~3~
-- 1 --
SPECIFICAIION
CARB~N FIBERS ~VING ~IGB S~ENGT~ AND
~IIG~ MODUL~S O~ ~L~Sl'ICITY ~ND POLY~R
CO~PnSITIO~ FOR T~EIR PROD~C~ION
T~CE~OLOGIC~L FIELD
This invention relates to carbon fibers having
h gh strength and high modulus of elasticity, and polymer
compositions for their production. More specifically,
it relates ~o carbon fibers csntaining silicon, or both
silicon and a specific transition metal atom, and polymer
composi~ions for their production.
BAC~GRO~ND TEC~OLOGY
Carbon fibers have light weight, high strength
and high modulus of elasticity, and thereore, their
utility is not only in sporting and leasure qoods, but
has been expanded to a wide range of fields including
aircraft, automobiles and building materials.
PAN-type carbon fibers derived from poly-
acrylonitrile as a raw material and pitch-type carbon
fibers obtained from petroleum and coal pitches as raw
materials are known as the carbon fibers.
Japanese Laid-Open Patent Publication No.
223316/1984 discloses a process for producing fibers
having high strength and high modulus of elasticity,
which comprises
; ta) hydrogenating a pitchr separating the solid
from the hydrogenation product, and removing low-bsiling
components by distillation to obtain a hydrogenated
pitch,
(b) heat-treating the hydrogenated pitch under
reduced pressure to give a mesophase pitch (containing
not more than 90 ~ by weight of mesophase carbon and at
least 30 % of optically anisotropic fibers), and there-
after
~c) melt-spinning the mesophase pitch, and
rendering the f.ibers infusible and carbonize them.
International Patent Laid Open W087/G5612 and
Japanese Laid Open Patent Publication No~ 209139/1987,
the corresponding Japanese priority application, dis-
closes an organopolyarylsilane being soluble in organ~csolv2nts and comprising organosilane segments in which
the skeletal portion is composed mainly of carbosilane
and polysilane, said segments being connected at random
via silicon-carbon linking groups.
Laid-Open International Patent ~0 87/05612 and
Japanese Laid-Open Patent Publication No. 21501S/1987,
the corresponding Japanese priority application, disclose
continuous SiC-C type inorganic fibers composed of mol-
ecules having carbcn and SiC as main constituents and
15 containing 5 to 55 ~ by weight of Si, 40 to 95 % by
weight of C and 0.01 to 15 % by weight of 0, said in-
organic 1bers showing excellent thermally resistant
strength and oxidation resi~tance with a volume re-
sistivity of 10 to 10 3 ohms~cm.
The above laid-open specifications describe a
process for producing inorganic fibers having properties
intermediate between the silicon carbide fibers and
carbon fibers, which comprise mixing an organic solvent-
soluble component of a coal or petroleum pitch with a
polysilane, and reacting the mixture under heat to syn-
thesize an organopolyarylsilane, and spinning it and
rendering the fibers infusible and curing the fibers.
However, in the above process, a pitch quite
free from an organic solvent-insoluble portion is
selected as one of the starting materials, and in the
production of the organopolyarylsilane, the reaction is
carried out under such conditions that no organic
solvent-insoluble portion is formed.
Accordingly, the resulting product as a spin-
ning material does not at all contain the above insolubleportion in the mesophase, which is said to be the most
important component for development of stEength by carbon
fibers~
Inorganic fibers obtained by spinning~ render-
ing the fibers infusible and curing them gives a dif-
fraction line ~002) corresponding to the graphite cry-
stals of caxbon under certain condit:ions~ but no orien-
tation inherellt to pitch fibers i5 noted~ Furthermoret
in the process described in the above patent documents,
the heat resistance o the fibers in an inert gas is
enhanced as the proportion of the pitch content in-
creases~ But~ on the contrary, the oxidation resistance
of the fibers is decreased, and moreover~ their mecha-
nical characteristics tend to be reduced markedly.
3apanese Laid-Open ~aten~ Publication No.
7737/1987 discloses a composite material comprising a
matrix of a plastic and as a reinforcing material hybrid
fibers consisting of inorganic fibers containing silicon,
titanium (or zirconium), carbon and oxygen and at least
one kind of fibers selected from the group consisting of
carbon fibers, glass fibers, boron fibers, aramid fibers
and silicon carbide Eibers having carbon as a core.
Japanese Laid-Open Patent Publication No.
266666~1986 discloses a coontinuous fiber bundle for use
in a composite material, said fiber bundle comprising
continuous fibers of ceramics (silicon carbide, silicon
nitride, aluminas etc.) or a heat-resistant material
(carbon~ metals, etc.) and short fibers, whiskers or
powders of the same material as above adhering to the
surface of the continuous fibers.
Japanese Laid-Open Patent Publication No.
195076/1985 discloses a method of improving the surface
hardness and oxidation resistance of carbon fibers, which
comprises adhering or contacting a silicon-containing
material to or with the surface of a caLbonaceous
material, melting the silicon-containing material to form
a modified layer composed of silicon carbide and carbon
on the surface.
~t~
3apanese Laid-Open Patent Publlc~tion No.
2S1175/1985 discloses a process for producing a molded
article composed of silicon carbide and carbon, which
comprises slowly o~idi~ing a molded carbon article at 400
to 600 C to render it light in weight and porous, and
then allowing a silicon-containing material ~o penetrate
into the pores and react at a t:emperature above the
meling point of the silicon-containing materialr
It is an object of this invention to provide
novel fibers having high strength and high modulus of
elastici~y.
Another object of this invention is to provide
fibers having high strength and high modulus of elas-
ticity containing crystalline carbon oriented in the
1~ direction of the fiber axis and consisting essentially of
silicon, carbon and oxygenO
Still another object of this invention is to
prov~de fibers having high strength and high modulus of
elasticity which when used as a reinforcing material for
a composite material, shows excellent we~tability with a
matrix material.
Yet another object of this invention is to
produce high strength and high modulus fibers which has
much higher modulus of elasticity than silicon carbide
2S fibers and excellent oxidation resistance with their
oxidation resistant temperature being higher by about 200
to 300 C than conventional pitch-type carbon fibers or
the PAN-type carbon fibers.
A further object of this invention is to pro-
vide a polymer composition suitable for production of the
fibers of this invention.
Other objects of this invention along with its
advantages will become apparent from the following de-
scription.
35According to this invention, the above objects
and advantages of this invention are firstly achieved by
~t ~9 l~a~
fibers having high strength and high modulus of elasti-
city comprising
~i~ crystalline carbon oriented suhstantially
in the direction of the fiber axis,
(ii) amorphous carbon and/or crystalline carbon
oriented in a direction different from the fiber axis
direction, and
(iii) a silicon-conta.ining component consisting
essentially of 30 to 70 % by weight of Si, 20 to 60 % by
weight of C and OOS to 10 % by weight of O, the propor-
tions being based on the total weight of silicon, carbon
and oxygenO
The above fibers of the inYention Sto be some-
times referred to as the first fibers of the invention)
can be produced by a process which comprises preparing a
spinning dope of a polymer composition comprising
(A) an organic silicon polymer resulting from
random bonding of a plurality of at least one type of
bond selected from the group consisting of units re-
presented by the following formula (a)
Rl
-Si- ~ a)
R2
wherein Rl and R2, independently from each
other, represent a hydrogen atom, a lower alkyl
group, a phenyl group or a silyl group ~-SiH3),
either via methylene groups (-CH2-) or both via methylene
groups and directly,
(B) a polycyclic aromatic compound in the s~ate
of a mesophase, a premesophase or a latently anisotropic
phase, and
(C) a polycyclic aromatic compound which is
optically isotropic but is not in the state of a premeso-
phase or a latently anisotropic phase,
at least a part of componen~ (A) being chemically bound
to component (B) and/or component (C~; spinning the
spinniny dope; rendering the sp~un fibQrs infusible under
tension or no tension, and pyrolyæing the infusible
fibers at a temperature of 800 to 3,~Q0 C in vacuum or
in an inert gaseous atmosphereO
The polymer composition used in the spinning
step has been provided for the first time by the present
inventors, and constitutes part of the invention~
The novel polymer composition can be produced
by heating the organic silicon polymer (A) and a pitch
which has no excessive heat history in an iner~ gas,
preferably at a temperature of 250 to 500 C, and melting
the resulting reaction product at 200 to 500 C together
with a pitch mainly having a mesophase, a premesophase or
a latently anisotropic phase.
The novel polymer composition and a process for
its production will first described~ and then, the above
fibers of the invention and a process for production
thereof.
The organic silicon polymer (A) is ob~ained by
the random bonding of the plurality of the bond units of
formula (a) via methylene groups (-CH2~) or via methylene
groups and directly.
In formula ~a), Rl and R , independently from
each other, represent a hydrogen atom~ a lower alkyl
group, a phenyl group or a silyl group (-SiH3). Examples
of the lower alkyl group are linear or branched alkyl
groups having 1 to 4 carbon atoms such as methyl, ethyl,
propyl and butyl groups.
The organic silicon polymer ~A) can be pro-
duced, for example, by rea~ting dimethyldichlorosilane
and metallic sodium to produce polymethylsilane, and
heating the polymethylsilane at a temperature of at least
400 C in an inert gas. In this example, an organic
silicon polymer in which a plurality of units of formula
(a~ wherein Rl and R2, independently from each other, are
hydrogen and methyl are bonded randomly via methylene
groups, or both via methylene groups and directly It
will be understood that when part of dimethyldichloro-
silane is replaced by diphenyldichlorosilane, an organicsilicon polymer is obtained which has units of formula
~a) wherein Rl and R2 in formula ~a), lndependently from
each other, represent hydrogen, methyl and phenyl.
The organic silicon polymer (A) has a weight
average molecular weight (Mw) of preferably 300 to l~OOOt
especially preferably 400 to 800.
The pitch which has no excessive heat history
may be originated from petroleum or coal. In particular
distilled oils or residual oils obtained by distilling
heavy oils produced by fluidized catalytic cracking of
petroleums, or heat-treated products of the distilled
oils or the residual oils are preferably used. These
pitches are usually optically isotropic ~these pitches
will be called optically isotropic pitches hereaEter).
Preferably, the optically isotropic pitches
contain 5 to g8 % by weight of components insoluble in
organic solvents such as benzene, toluene, xylene and
tetrahydrofuran~
These pitches are polycyclic aromatic compounds
if their chemical structure is considered, and are pre
ferably relatively high-molecular-weight compounds having
a weight average molecular weight of about 100 to 3,000.
The weight average molecular weight may be measured
directly by gel permeation chromatography ~GPC~ if the
pitch does not contain components insoluble in organic
solvents. On the other hand, when the pitch has com-
ponents insoluble inorganic solvents, the pitch is
hydrogenated under mild conditions to change the organic
solvent-insoluble components into organic solvent-soluble
components, and the molecular weight of the treated pitch
is then measured by GPC.
-- 8
The organic silicon polymer ~A) and the
optically iso~ropic pitches are hea~ed and reacted in an
inert gas such as nitrogen gas or argon gas, preferably
at a temperature of 250 to 500 CO If the reaction
temperature is e~cessively low, the reaction tfor ex-
ample/ the bonding o~ the aromatic carbons of the pitch
to the organic silicon polymer) is difficult. If, on the
other hand, the reaction temperature is excessively high,
the decomposition of ~he reac~ion product and its con-
version to a higher-molecular-weight product occur
vigorouslyO
The proportion of the pitch used in this re-
action is preferably 83 to 47900 parts by weight per 100
parts by weight of the organic silicon compound~ If the
proportion of the pitch used is too small, the amount of
silicon carbide component in the finally obtained fibers
is large~ and fibers having a high modulus of elasticity
are difficult to obtain. If this proportion is exces-
sively large, the amount of the silicon carbide component
formed becomes small, and fibers having excellent wetting
property with respect to the matrix and excellent oxida-
tion resistance are difficult to obtain.
The reaction product obtained by the above
reaction is then heat-melted with a pitch in the meso-
phase, the premesophase or in a latently anisotropicstate.
The mesophase pitch can be prepared by heating
a petroleum or coal pitch at 300 to 500 C in an inert
gas, and polycondensed while the resulting light frac-
tions are removed.
A suitable petroleum or coal pitch contains 5to 98 ~ by weight of components insoluble in an organic
solvent such as benzene, toluene, xylene or tetrahydro-
furan like the pitch used to react with the organic
silicon polymer.
By heat-treating the above starting pitch
~g ~ ?,?
either directly or af~er as required~ csmponents soluble
i.n organi~ sGlvent are remo~ed, the mesophase pitch can
be obtained. The advan~age of removing ~he organic
solvent-soluble components is to facilitate the formation
of a mesophase by remoYing the soluble oomponents which
are dificult of forming a mesophase and to obtain a
pitch having high optical anisotropy and a low melting
point.
The mesophase pitch is a polycyclic aroma~ic
oompound in view of its chemical s~ructureO Preferably,
it has a melting point of 200 to 400 C, a weight average
molecular weight of 200 to 10,000 and a degree of optical
anisotropy of 20 to 103 %, and contains 30 to 100 % of
components insoluble in benzene, toluene, xylene or
tetrahydrofuran. When the starting pitch is subjected to
an operation of removing the organic solvent-soluble
components, the mesophase pitch has a melting point of
200 to 350 C and a weight avera~e molecular weight of
200 to 8,000. The melting point can be determined by an
ordinary capillary method in a nitrogen box ~the same
hereinafter~.
The premesophase pitch can be produced by, for
example, hydrogenating a petroleum or coal pitch with a
hydrogen donor such as tetrahydroquinoline or hydroge-
nating the pitch under hydrogen pressure in the optionalpresence of a catalyst, and then heating the resulting
hydrogenated pitch for a short period of time at high
temperatures under reduced pressure.
~hen the hydrogenation is carried out by using
tetrahydroquinoline, at least 30 parts of the quinoline
is added to 100 parts by weight of ~he pitch, and the
mixture is heated at 300 to 500 C.
When hydrogenation is carried out by using
hydrogen, a catalyst such as a oobalt-molybdenum system
or an iron oxide system and a solvent such as quinoline
are optionally added to the starting pitch, and the pitch
-- 10 --
is hydrogenated at 400 to 500 C under a partial hydrogen
pressure of at least 10 kg~cm2. The resulting product is
heat-treated at a temperature of at least 440 ~C under a
pressure oi not more than 5~ mmHg for a period of not
more than 60 minutes after optionally it is filtered and
subjected to a treatment of removing th2 solvent and the
light componentsO The treating time is determined by the
treating ~empera~ure. Preferably7 ~he ~reatment is
performed at the highest possible temperature or the
shortest possible timeO ParticularlyO treatment for a
time of not more than 15 minutes is ad~an~ageous.
The premesophase pitch is a polycyclic
aromatic compound in view of its chemical structure~ and
preferably has a melting point of 200 to 350 C and a
weight average molecular weight of 600 to 6,000, and
contains at least 5 % of components insoluble in
quinoline~
The premesophase state, as referred to herein,
denotes the state which is optically isotropic at room
temperature but on heating to a high temperature of at
least ~00 C, can change to a mesophase state. The
premesophase pitch alone is spun, rendered infusible,
and pyrolyzed, orientation occurs in the pyrolyzing step,
and high modulus fibers can be obtained in the same way
as in the case of using a mesophase pitch~ The advantage
of using the premesophase pitch is that it can be spun
at lower temperatures than when the mesophase pitch is
used.
The pitch in the latently anisotropic state can
be obtained by removing light fractions from a heavy oil
(to be referred to sometimes as the FCC slurry oil~
obtained by fluidi~ed catalytic cracking of petroleums,
heat-treating the resulting pitch at 300 to 500 C, and
subjecting the resulting optically anisotropic mesophase
pitch to a hydrogenation treatment until the mesophase
contained therein changes into substantially quinoline-
soluble componen~s and the pi~ch as a whole forms anoptically isotropic homo~eneous phase.
Various known methods used for hydrogenation of
the aromatic ring may be used in the hydrogenation. For
example~ there can be used a method involving reduction
with an alkali metal, an alkaline earth metal and a
compound of any of these~ an electrolytic reduction
method, a hydrogenation method in a homogeneous system
with a complex compound catalyst, a hydrogenation method
in a heterogeneous system using a solid catalyst, a
hydrogenation method under a hydrogen pressure in the
absence of catalyst, and a hydrogenation method using a
hydrogen donor such as tetralin.
The hydrogenation may be carried out at a
temperature of not more than 400 C under a pressure of
not more than 200 atmospheres, although these conditions
may vary depending upon the method used. The resulting
hydrogenated pitch may be maintained in the heat-melted
state to enhance its thermal stability.
The heating temperature at this time is pre-
ferably above the melting temperature but does not exceed
450 C. Heating at high temperatures may result in the
formation of a new mesophase~ The formation of too large
an amount of the mesophase is undesirable because it
increases the softening point of the pitch~
The pitch in the latently anisotropic state is
a polycyclic aromatic compound in view of its chemical
structure. Preferably, it has a melting point of 200 to
350 C and a weight average molecular weight of 200 to
6,000, and is soluble in quinoline.
The latent anisotropy, as used herein, denotes
anisotropy which is attributed to the orientation of
molecules in the direction of an external force such as a
shearing force or a stretching force, which occurs upon
application of the external force. For example, when
this pitch is spun, rendered infusible ~cured~ and
~g ~
- 12 -
pyrolyzed in accoLdance with an ordinary method of pro-
ducing pitch-type carbon fibers, fibers oriented in the
direction of the fiber axis are obtained~
The pitches in the mesophase~ premesophase or
the latently anisotropic state may be used singly or in
combination.
These pitches and the reaction product between
the organic silicon polymer and the optically isotropic
pitch, are melted at a temperature in the range of 200 to
500 C. The pitch in the mesophaseY premesophase or
the latently anisotropic state is used in a proportion of
5 to 50,000 parts by weight9 preferably 5 to 10,000 parts
by weight, per lOQ parts by weight of ~he reaction pro-
ducto
If the proportion of the pitch is less than 5
parts by weight, highly elastic pyrolyzed fibers are dif-
ficult to produce as a final produc~. If it exceeds
50,000 parts by weight, it is difficult to obtain final
fibers having excellent wettability with respect to the
matrix and excellent oxidation resistance.
Thus~ according to this invention, there is
provided a polymer composition, comprising (A) an organic
silicon polymer, (B) a polycyclic aromatic compound in
the mesophase, and (C) an optically isotropic polycyclic
aromatic compound, at least a part of component (A) being
chemically bound to component (Bl and~or component (C) by
reaction. The formation of a chemical bond can be deter-
mined by the increase of the amount of that portion of
the polymer composition which is insoluble in, ~or
exampler toluene over the total amount of toluene-
insoluble portions of the individual components. For
example, if the polymer composition comprises 1 part by
weight of the reaction product obtained between 30 parts
by weight of the organic silicon polymer (A~ and 70 parts
by weight of component tC), and 14 parts of component
(B), the amount of the insoluble portion of the polymer
~ ,`,~?~,r~
- 13 -
composition increases to about ].03 to 1~03 time based
on the total amount oE the insoluble portic)ns of the
indiYidual componentsO Generally~ this figure tends to
be larger as the total amcunt oi- components SA~ and (C~
bcomes larger than the amount oi component (B~ and the
proportion of COmpOJlent (A~ becomes larger in the total
amount of components (A) and (C)O
The polymer composition of this invention is
composed of the constituents (A~, ~s3 and (C)~ and at
leasS a part of tlle silicon atoms o component (A) is
bonded to tlle carbon atoms on the aromatic rings of
component ~B~ and~or component (C)O Preferably, the
weight ratio of of component (A) to the total amount of
components (B) and ~C~ is from 1:0~5 - 5,000, and the
weight ratio of component ~B) to component (C~ is
1-0~02 - ~.
If the weight ratio of of component (A) to the
total amount of components (B) and ~C) is below 0.5, the
amount of the mesophase component in the polymer com-
position is insufficient, and fibers obtained from thepolymer composition have low strength and modulus of
elasticity. If this ratio exceeds 5~000, the amount of
the organic silicon in the polymer composition is in-
sufficient, and fibers obtained from this composition
have lowered oxidation resistance and tend to have
reduced wettability with an FRP matrix.
If the weight raito of (C) to tB~ is less than
O oO2 ~ the polymer composition has reduced spinnability in
melt spinning, and its spinning becomes extremely dif-
ficult with the occurrence of fiber breakage owing to thenon-uniform viscosity of the spinning dope~ If the above
weight ratio exceeds 4, the amount of the mesophase
component in the polymer composition becomes insufficient,
and fibers obtained from the composition have lowered
strength and modulus.
The polymer composition of this invention
~6~
cont~ins 0.01 to 30 % by weight of silicon atoms, and has
a weight average molecular weigh~ of 200 to 11,000 and a
melting point of 200 to 400 C.
If the silicon atom content of the polymer
composition is less than 0~01 %, the amount of the amor-
phous phase composed of Si 9 C and O or the ultrafine
beta-SiC particles in the fibers formed from the com-
position is too small, and therefore~ no marked im-
provement in the wettability of the resulting fibers ~ith
respect to the FRP matrix and the oxidation resistance of
the fibers is achieved. On the other hand, if the
silicon atom content exceeds 30 %~ the high elasticity of
the fibers owing to the orientation of ultrafine graphite
crystals in the fibers and the improved heat resistance
of the fibers in a non-oxidizing atmopshere cannot be
achieved~ and the resulting fibers do not at all differ
from SiC fibers.
If the weight average molecular weight of the
polymer composition is lower than 200, the composition
does not substantially contain a mesophase. From such a
composition, thereforei highly elastic fibers cannot be
obtained. If its weight average molecular weight is
larger than 11,000, the composition has a high melting
point and becomes difficult to spin.
A polymer composition having a melting point
lower than 200 C does not substantially contain a meso-
phase, and as-spun fibers from this composition tend to
melt adhere at the time of curing, pyrolyzed fibers
having high strength and modulus of elasticity cannot be
cbtained. If it is higher than 400 C, the composition
is decomposed during spinning, and becomes difficult to
spin.
Preferably, the polymer composition contains 10
to 98 ~ of components insoluble in an organic solvent
such as benzene, toluener xylene and tetrahydrofuran and
has a degree of optical anisotropy at room temperature of
5 to 97 %~
- 15 -
If the proportion of the organic solvent-
insoluble portion of the polymer composition is less than
10 ~, or the degree of optical anisotropy of the composi-
tion is less than 5 %, the mesophase is hardly oriented
in the direction of the fiber axis at the time of melt-
spinning the composition. Hence, even when the resulting
as-spun fibers are cured and pyrolyzed, there can
only be obtained fibers having low strength and low
modulus of elastiGity. When the composition contains
more than 98 % of the organic solvent-insoluble portion
or has a degree of optical anisotropy of more than 97 %,
the amount of the mesophase in the composition becomes
too large, and the composition becomes difficult to spin.
To produce the first fibers of this invention
from the polymer composition of this invention, a spin-
ning dope of the polymer composition is preparedl and
spun, and the resulting as-spun fibers are cured under
tension or under no tensionO The resulting infusible
fibers are pyrolyzed in an inert gaseous atmosphere at a
te~perature of 800 to 3,000 C.
The spinning dope is prepared usually by heat-
melting the polymer composition and as required, filter-
ing the melt to remove substances detrimental to spin-
ning~ such as microgels or impurities. Its spinning is
carried out by an ordinarily used synthetic resin
spinning apparatusO
The temperature of the spinning dope to be spun
is advantageously 220 to 4~0 C although it varies de-
pending upon the softening temperature of the starting
composition.
As required, a spinning cylinder is mounted on
the spinning appratus, and the atmosphere of the inside
of the spinning cylinder is formed into an atmosphere of
at least one gas selected from air, an inert gas, hot
air, a hot inert gas, steam and ammonia gas, and by
increasing the wind up speed, fibers having a small
- 16 -
diameter can be obt~inedO The spinning speed in melt
spinning can be varied within the range ~ 50 to 5,000
m/min. depending upon the properties of the starting
composition.
The re~ulting as spun fi~ers are then reduced
infusible Scuredi under tension or under no tension.
A typical method of curing is to heat the
as-spun ribers in an oxidizing atmosphere~ The tem-
perature at this time is preferably 5Q to 4~0 CO If the
temperature i5 excessively low, no bridging ~akes place
in the polymer constituting the as-spun fibers. If this
temperature i5 exCeBSively high, the polymer burns.
The purpose of curing is to bridge the polymer
constituting the as-spun fibers ~o proYide an insoluble
1~ and in~usible three dimensional structure and to preYent
it from being melted with the adjacent fibers melt-
adhering to each other in the subsequent pyrolyzing step~
The gas constituting the oxidizing atmosphere at the time
of curing is pr~ferably, for example, air~ ozone, oxygen,
chlorine ga~, bromine gas, ammonia gas or a gaseous
mixture of these~
Another method of curing comprises applying
gamma~ray irradiation or electron beam irradiation to the
as-spun fibers in an oxidizing or non-oxidizing atmos-
phere optionally with heating at low temperatures.
The purpose of applying gamma-rays or electron
beam irradiation is to polymerize the polymer forming the
as-spun fibers to a greater degree, and thereby prevent
the as-spun fibers from melting and thus losing the fiber
shape.
The suitable irradiation dose of ~amma-rays or
electron beams is 106 to 101 rads.
The irradiation may be carried out under vacuum
or in an atmosphere of an inert ga~ or an oxidizing gas
such as air, ozone, oxygen, chlorine gas, bromine gas~
ammonia gas or a gaseous mixture thereof.
f ~ r ~
~~ 17 ~
The operation of curing may be carried out
under tension or under no tension. The tension to be
applied is preferably 1 to 500 g/mm2~ Application of a
tension o~ not more than 1 9/mm2 cannot keep the fibers
taut. On the other hand, when this operation is carried
out under no tension, the as-spun fibers assume a wavy
form because of their shrinkage, but since this can
Erequently be corrected in the subsequent curing step,
tension is not always essential.
The resulting infusible fibers are pyrolyæed in
vacuum or in an atmosphere of an inert gas at a temp~ra-
ture of 800 to 3~0~0 C. The pyrolyzing can be carried
out under tension or under no tension. Preerably, it is
carried out under tension because if the fibers are
pyrolyzed at high temperatures under a tension of, for
example, 0.001 to 100 kg/mm2, inorganic fibers having
high strength and little flex can be obtained.
It is presumed that in the temperature elevat-
ing process, carbonization begins to become vigorous at
about 700 C, and is almost completed at about 800 C.
To obtain higher temperatures than 3,000 C, an expensive
apparatus is required, and there is no industrial advant-
age. Hence, pyrolyzing is carried out at a temperature
~f ~00 to 3,0~0 C.
Thus, according to this invention, there are
provided high strength and high modulus fibers containing
components ~i), (ii) and (iii) as stated at the outset of
the section ~Disclosure of the Invention" are obtained.
Component (i) is crystalline carbon oriented
substantially in the direction of the fiber axis. It is
believed in relation to the production process described
above that this carbon is derived from a polycyclic
aromatic compound which is in the mesophase, or in other
words, optically anisotropic.
Owing to the presence of component (i), a
structure known in the art, that is, a radial structure,
an onion structure, a random structure, a core-radial
structure~ a skin onion structure or a mosaic structure
is observed in the c~vss section of the fibers of this
inventionO
Component (ii) is amorphous carbon and/or
crystalline carbon oriented in a direction different from
the fiber axis direction. Like~wise, in relation to the
production process described above, this component is
believed to be derived from an optically isotropic poly~
cyclic aromatic compound.
Crystalline carbon has a crystallite size of
not more than 500 angstrom, and is ~n ultrafine graphite
crystal oriented in the direction of the fiber axis in
which by a high-resolution electron microscope having a
resolution ability of 1.5 angstrom, a fine lattice image
corresponding to ~002) plane with an interplanar spacing
of 3.2 angstrom.
In the fibers of this invention~ microcrystals
which are three-dimensionally arranged with a small
interlayer distance are effectively formed.
The silicon-containing component tiii) con-
sisting essentially of silicon, carbon and oxygen may be
an amorphous phase or an aggregation of a crystalline
particulate phase consisting essentially of crystalline
SiC and an amorphous SiOx (O<x<2) phase.
The crystalline particulate phase consisting
essentially of crystalline SiC may have a particle
diameter of not more than 500 angstrom.
The distributed state of silicon in the fibers
can be controlled in relation to the atmosphere in which
fibers are pyrolyzed for production of fibers, the size
and concentration of the mesophase in the starting
material. For example, if the mesophase is grown to a
large size, the silicon-containing polymer is liable to
be pushed out onto the fiber surface layer, and after
pyrolyxing, forms a silicon rich layer on the fiber
surface.
- 19 -
The fibers of this invention preferably contain
00015 to 200 parts by weight of component ~ per 100
parts by weight of components (i) and (iii) combined, and
the weight ratio of component ~i~ to component (ii) is
1:0~02 ~ ~.
If the proportion of component (iii~ is less
than 0~015 part by weigh~. per 100 parts by weight of
components (i) and ~ combined~ the resulting fibers
are much the same as pitch fibers, and an improvement in
oxidation resistance and wettabili~y canno~ be expec~ed~
If the proportion exceeds 200 parts hy weight, fine
crystals of graphite are not effectively formed, and
ibers of a high modulus of elasticity are difficult to
obtain~
lS The fibers of this lnvention ~omprises pre-
ferably 0.01 to 29 % by weight of silicon, 70 to 93.9
by weight of carbon and 0.001 to 10 % by weight of
oxygen, especially preferably 0.1 to 25 ~ by weight of
silicon, 74 to 99~8 % by weight of carbon and 0.01 to 8 %
by weight of oxygen, based on the total weight of
silicon, carbon and oxygen.
As second fibers of this invention, the present
invention provides fibers having high strength and high
modulus comprising
(i) crystalline carbon oriented substantially
in the direction of the fiber axis,
5ii) amorphous carbon and/or crystalline carbon
or.iented in a direction different from the direction of
the fiber axis, and
(iii') a silicon-containing component sub-
stantially composed of 0.5 to 45 ~ by weight of a metal
selected from titanium, ~irconium and hafnium, 5 to 70 %
by weight of Si, 20 to 40 % by we.ight of C and 0.01 to
30 % by weight of O, the proportions being based on the
total weight of said metal, silicon~ carbon and oxygen.
According to this invention~ the second fibers
~3~ t~
- 20 -
of this invention can be pro~uced by a process which
comprise6
preparing a spinnins dope of a polymer com-
position comprising
tA') an organic silicon polymer resulting from
random bonding of a plurali~y of units of at least one
kind select.ed from the group consisting o units of the
following formula ~a)
-Si~ ... (a)
R2
wherein Rl and R2, independently from each
other/ represent a hydrogen atGm~ a lower alkyl
group, a phenyl group or a silyl group ~-SiH3~,
and
at least one unit of formula (b)
-Si- ... (b)
R
wherein Rl is as defined abover and R3 re-
presents -M or -OM, and M represents one equiva-
lent of a metal selected from the group con-
sisting of titaniuum, zirconium and hafnium,
via methylene groups (-CH2-) or both via methylene groups
or directly,
(B) a polycyclic aromatic compound in the
mesophase, premesophase or the latently anisotropic
phase, and
(C) an optically isotropic polycyclic aromatic
compound which is not in the premesophase or the latently
anisotropic phase,
part of component (A~ being chemically bonded to com-
ponent ~B) and~or component (C);
- 21 --
spi.nnitlg the spinning dope,
rendering ~he ~ibe~s infusible under tension or
under rlo tel-sion; and
pyrol~zin~ the resul~ing infusible ~ibers in
va~uum or in an atmosphere o~ an .inert gas at a tem-
perature of 800 to 3,000 CO
The polymer compos.ition used in the spinning
step has been provide~ for the fir5~ time by ~he present
inventors and constitute part of the present invention.
The novel polymer composl~ion can be produced
by heating the organic silicon polymer (~) described
above in the production of ~he firs~ ~ibers of the
invention (to be sometimes referred to as the first
organic silicon polymer) and an optically isotropic pitch
1~ in an inert gas at a te~perature of preferably 250 to
500 C, then reacting the reaction product with a
transition metal compound of formula
MlX4
wherein Ml represents titanium, zironium or
hafnium, and X may be any moietyp for example a
halogen atom, an alkoxy group~ or a chain
forming group such as a beta~diket.one! which
permits M to be bonded to the silicons of the
precursor reaction product directly or through
an oxygen atom by condensation,
at a temperature oX 100 to S00 C; and heat-melting the
reaction product with a pitch in the mesophase, the
premesophase or the latently anisotropic state at a
temperature of 300 to 500 C.
The first organic silicon polymer/ the
op~ically isotropoic pitch and the heating condition~
therefor are as described hereinabove.
The precursor reaction product obtained by
heating is then reacted with the transition metal
- ~2 -
csmpound MlX4. By this reaction, the silicon atoms of
the precursor reaction product may be at least partly
bonded to the me~al M directly or through an oxygen atom.
If the reaction temperature is low, the con-
S densation reaction between the precursor reaction productand the compound of formula MlX4 does not proceed. If
the reaction temperature is excessively high, the cross~
linking reaction through M proceeds excessively to cause
gellation or the precursor reaction product itself con-
denses and becomes high in molecular weight. In somecases~ MX4 volatilizes, and a composition for obtaining
excellent fibers cannot be obtained.
The reaction product can also be prepared by
reacting the reaction product obtained after the reaction
f the organic silicon polymer (A) with the transition
metal compound, with a pitch.
The above reaction product contains the organic
silicon polymer (A') which results from random bonding of
a plurality of the units represented by formula (a) to at
least one unit of formula (b) through methylene groups or
both through methylene groups and directly without the
intermediary of methylene groups.
The units of formula (b~ may be~ for e~ample,
as follows when Ti(OC4Hg)4 is used as the transition
metal CompoundO
Rl Rl
-Si- and -Si-
%Ti 0%Ti
The reaction temperature at this time is especially
desirably 200 to 400 C.
The reaction product obtained by the above
reaction is then heat-melted with a pi.tch in the meso-
phase, premesophase or the latent anisotropy.
It should be understood that as regards these
3 ~ ¢
-- 23 --
pitches and l:he heat-rlle:lt.ing condltion~ he same
descrip~ion as ~ha~ ror ~he polymer composil:ion used in
the produc:t.ion vf the first ib~ers ~to be sometimes
referred to as the firc;t polymer COJllpO~iitiO~13 will applyO
The above polymer comlposition Ito ~2 somet:imes
referred to as the transition metal~conta.ining reaction
pros]uct or the second polymer composi~ionj may also be
produced by a process which comprises reacting the irst
organic silicon polyllner (Aj with an optically isotropic
1~ pitch, and reactirlg the resulting product wi~h a pol3r-
s:yclic aromatic compound such as one in ~he mesophase and
a transition metal compourld successively or together~
Thus9 accordin~ to this inventior;~ there is
provided a polymer composition comprising ~A' ) an organic
sil.ic3n compound, (B) a polycyclic aromatic compound sus~h
as one in the mesophase~ and (C~ an optically isotropic
polycyc~ic aromatic compound, at least part of the com-
ponent (A') being chemically bonded to component ~B)
and/or component (C).
The second polymer composi~cion of this
invention co~prises the components (A')~ (B) and ~C), and
the silicon atoms of the component (A') are at least
partly bonded to the carbon atoms of the aromatic rings
of component ~B) and/or component (C). The weight ratio
of component ~A') to the total sum of components (~) and
tC) is preferably 1:0~5 - 5~000r and the weight ratio of
eomponent (C) to component (B) is preferably 1:0~02 - 4O
I the weight .ratio of componen~ ~A') to the
total sum of components (B) and (C) is less than 0.5, the
amount of the mesophase component in the second polymer
composition is insufficient, and ibers obtained from
this polymer have low strength and ~odulus of elasticity.
I~ this ratio exceeds 5,000, the amount of the organie
silicon compound in the second polymer composition
becomes insufficient, and fibers obtained f rom this
polymer have low oxidation resistance. Furthermore, the
-- 2~ -
wettability of the fibers with respect to an FRP matrix
:ellds t~ be lowO
Xf the weight ratio of ~C~ ~o (B) is less than
O oO2 ~ the spinnability o:E the slecond polymer composition
5 in its melt~spirlrling is ~egradeld~ and f iber breakage
occurs o~ing to the norl-unifor~n viscosity of the dope.
Herlce~ the polymer composition becomes extremely dif-
ficult to spinO If 'che above weight ratio Zexoeeds 4,, the
amount o the ~esophase component i n the second polymer
composition is insllE:Lc.ient, and fibers obtained from the
polymer tends l:o have low s~rength and modulus of elas-
ticity O
Preferably7 in component IA' ~ 7 tbe ratio of the
total number of units Si-CH2 to that of units Si-Si is
15 ~ri'chin 1 0 - 20, and 0.2 to 35 ~ o units M of the tran
sition metal compound is contained based OS! the total
w@ight of the units Si~CH2 and units 5i Si.
The second polymer co~position preferably
contains 0 oOl to 30 %, especially O.OS ~o 30 %, of
silicon atoms, and 0,005 to 10 % of M, and has a weight
average molecular weight of 200 to 11,000 and a m21ting
point of 200 to 400 C.
If the content of silicon atoms in the second
polymer composition is less than 0~01 %, the wettability
Of the resulting fibers with respect to an FRP matrix and
the oxidation resistance of the fibers do not markedly
show an improvement~ On the other hand, i it exceeds
30 %, the orientation of the ultrafine graphite crystals
in the fibers makes it impossible to achieve high
elasticity in the fibers, and an improvement in the heat
resistance of the fibers in a non-oxidizing atmosphere,
and the fibers do not differ at all from 5iC fibersO
Since the second polymer composition contains M
in addition to silicon, the composition shows a further
improvement in mechanical properties, wettability wîth
plastics~ If the content af M is less than 0.005 %~ the
- 25 -
above properties are searcely exhibited. If it exceeds
10 %~ both a high-melting product which is extremely
crosslinked and the unreacted MX~ exist in the com-
position, and it becomes very dlifficult to melt-spin a
dope of th~ composition.
If the second polymer composition has a weight
average molecular weight lower than 200, it hardly con-
tains a rnesophase~ and therefore, high elasticity fibers
cannot obtained f rom the composition~ If its weight
10 average molecular weight is larger than 11,000~ the
composition has a high melting point and is difficult ~o
spin.
If the second polymer composition has a melting
point lower than 2û0 C, it does no~ subs~antially con-
tain a mesophase, and as-spun fibers obtained by spinning
this composition are liable to melt-adhere when subjec~ed
tG curing. Thus, fibers having high strength and modulus
of elasticity cannot be obtained. If its mel~ing point
is higher than 400 C, the composition undergoes de-
compositon during spinning, and is difficult to spin.
Preferably, the second polymer composi~ioncontains 10 to 98 % of a portion insoluble in an organic
solvent such as benzene, toluene, xylene or tetrahydro-
furan, and has a degree of optical anisotropy at room
temperature of 5 to 97 ~.
If the proportion of the organic solvent-
in~oluble portion of the second compoqition is less than
10 % or its degree of optical anisotropy is less than
5 %, the meqophase is hardly oriented in the direction of
the fiber axis when the composition is melt-spun. Accord-
ingly~ when the as-spun fibers are cured and pyrolyzed,
there can only be obtained fibers having low strength and
modulus of elasticity. On the other hand, when the
second poly~er composition contains more than 98 % of the
organic solvent-soluble portion, or has a degree of
optical anisotropy of more than 97 ~, the amount of the
~s ~
- 26
mesophase in the composition be~com~s ex~essive, and the
composi ti on i s di f f icu 1 t tQ spi n O
The secolld f ibers may be produced f rom the
second polymer composition of this invention by quite the
5 same process a5 that for producing the first fibers of
thi s i nverl~i on .
Thus7 the present invention also provides
fibers of high strength and elasticity comprising com-
ponents (i), ~ii) and (iii') described aboYe~
The component (i) is crystalline carbon
oriented substantially in the direction of the fiber
axis. In relation to the above production process, ~his
component is believed to be derived f rom a polycyclio
aromatic compound in the mesophase, or in other words, an
optically anisotropic polycyclic aromatic compound. In
the fibers of this invention, a structure well known in
the art is observed in a iber cross-section owing to the
presence of component (i~, namely a radical struc~ure, an
onion structure, a random structure, a core-radial struc-
ture, a skin onion structure, or a mosaic structure.
The constituent component (ii~ is amorphouscarbon and/or crystalline carbon oriented in a direction
different from the direction of the fiber axis~ Like-
wise, in relation to the above production process, it is
believed that component Sii3 is derived from an optically
isotropic polycyclic aromatic compound.
The crystalline carbon has a crystallite size
of not more than 500 angstrom. It is in the form of
ultrafine graphite crystal particles in which under a
high-resolution electron microscope, a fine lattice image
corresponding to (002) plane having a planar spacing of
32 angstrom and oriented in the direction of the fiber
axis is observed.
In the fibers of this invention, microcrystals
having a small in~erlayer distance and arranged three
dimensionally are effectively formed.
- 27 -
The silicon~contain.ing component ~iii') con-
sisting essentially of the transition metal, silicon,
carbon and oxygen may be an amorphous phase, or an ag-
gregate consisting substantially of a crystalline fine
particulate phase consisting of silicon~ carbon and a
transition metal selected from the group consisting of
titanium, zirconium and hafnium and an amorphous SiOy
(0<y<2~ and MOz (M is Ti, Zr or Hf, and 0~z<2~.
The amorphous phase of the silicon-containing
component tends to form when the pyrolyzing temperature
.in the production of the fibers is lower than 1000 C.
The aggregate of the crystalline fine particulate phase
and the amorphous phase tends to form when the pyrolyzing
temperature is 1700 ~ or higher.
The crystalline fine particulate phase consists
of crystalline SiC, MC (M is as defined above), a cry-
stalline solid solution of SiC and MC, and MCl x ~D<x~l),
and may have a particle diameter of not more than 500
angstrom.
At pyrolyzing temperatures intermediate between
the above temperatures, a mixture of the aggregates
forms. The amount of oxygen in the fibers can be con-
trolled by the proportion of MX4 added or the curing
conditions.
The state of distribution of the component
(iii') may also be controlled by the atmosphere of
pyrolyzing, or the size and concentration of the meso-
phase in the starting material. For exampleg when the
mesophase is grown to a large size, the component (iii~)
is liable to be pushed out onto the surface of the
fibers.
Preferably, the fibers of this invention con-
tain 0.015 to 200 parts by weight of component (iii) per
100 parts by weight of the components (i) and (ii) com-
bined, and the ratio of components (i) to (ii) is
1 : 0 . 0 ~
- 28 -
If the amQunt of component (iii) is less than
O.OlS part by weight per lO0 parts by weight oE com-
ponents ~i) and ~ii) combined, khe resulting fibers do no
differ from pitch fibers, and an improvemel1t in oxidation
resistance and wettability can Tnardly be e~pectedO If
the above proportion exceeds 200 parts by weight, fine
crystals of graphite are not efEectively formed, and
fibers having a high modulus of elasticity are difficult
to obtain.
The fibers of this inven~ion preferably consist
of O~Ol ~o 30 % by weight of silicon, O.Ol ~o lO % by
weight of the transition metal ~Ti, Zr or Hf~, 65 to
99.9 ~ by weight of carbon, and O.OOl to lO % by weight
of oxygen, particularly preferably O.l to 25 % by weight
15 of silicon, 0.01 to 8 % by weight of the transition
metal, 74 to 99.8 % by weight of carbon~ and OoOl to 8
by weight of oxygen.
The first and second fibers may be advantage-
ously used as a reinforcing material for composite
materials. Examples of such composite materials are as
follows:-
tl) A fiber-reinforced composite material
comprising a plastic as a matrix.
(2) A fibee-reinforced composite material
comprising ceramics as a matrix.
~ 3) A fiber-reinforced composite material
comprising carbon as a matrix.
(4) A fiber-reinforced composi~e material
comprising a pyrolyzed product of the polymer composition
~f this invention as a matrix.
(5) A composite material comprising a metal as
a matrix.
These examples will be described successively.
For the composite mater al comprising a plastic
as a matrix, both the firs~ and the second fibers of the
invention can be used.
- 2~
Incorporation of the fibers rnay be effected by,
Eor example, a method comprising incorporating these
fibers in the matrix, monoax7ally or multiax.ially, a
method comprising using the fibers in the form of a woven
fabric such as a plain~weave fabrlc? a satin weave
fabric, a twill fabricF an imitation gauze fabric, a
helical weave fabric and a three-dimensionally woven
fabric, or a method comprising using the fibers as
chopped fibers.
Examples of the plastic include epoxy re~ins~
unsaturated polyester resins, phenolic resins, polyimide
resinsp polyurethane resins~ polyamide resins, poly-
carbonate resins, silicone resins, fluorine-containing
resins, nylon resins, polyphenylene sulfide resins,
polybutylene terephthalate, ultrahigh-molecular-weight
polyethylene, polypropylene, modified polyphenylene oxide
resins, polystyrene, ABS resins, vinyl chloride resins,
polyether-ether ketone resins and bismaleimide resinsO
These plastic composite materials can be pro-
duced by methods known E~ se, for example, tl) a handlayup method, (2) a matched metal die method, (3) a break
away method, ~4) a filament winding method, (5) a hot
press method, (6) an autoclave method, and (7) a con-
tinuous pulling method.
According to the hand layup method (1), the
fibers are cut and spread densely on a mold. Then~ the
plastic containing a catalyst is coated on the spread
fibe~s ~y means of a bru~h or a roller and allowed to
cure naturally. The mold is then removed to produce a
composite material.
According to the matched me~al die method ~2),
the fibers are impregnated with the plastic, a curing
agent, a filler and a thickening agent, and then molded
under heat and pressure to form a composite material.
Depending upon the form of the material during the
molding, either the SMC (~heet molding compound) method
1 r~
~ 30 ~
or the BMC ~bulk molding compound1 method may be
selected.
According to the break away method (3)~ sheets
of the fibers are impreqna~ed wi~h the plastic and pre--
cured to form prepregs. The prepregs are wound up arounda tapered mandrel, and after curing, the cured composite
material i5 pulled out~ A hollow article of a complex
shape can be produced by ~his methodO
According to the filament winding methed ~4),
inorganic fibers impregnated with a thermose~tinq resin
such as an epoxy resin or an unsaturated polyester resin,
wound around a mandrel, and treated to cure the resin.
The cured product was removed from the mandrel to fsrm a
composite material~ This method is carried out by a wet
procedure or a dry procedure ~using a prepreg tape).
According to the hot press method ~5), prepreg
sheets of the fibers are stacked in one direction or at
any desired angle, and the stack i5 heated under pressure
by a hot press to form a composite material in the form
f a plate.
According to the autoclave method (6), prepregs
are stacked on a mold, and wrapped with a special rubber.
In a vacuum condition, the stack is put in a high-
pressure kettle and heated under pressure to obtain a
cured composite material. This method is suitable for
production of complex shapes.
According to the continuous pulling method (7~,
the fibers and the plastic are separately fed into a
molding machine, and mixed just before a mold. On the
3~ way, the mixture is passed ~hrough a heating oven, and
continuously ~aken up as a continuous long composite
material.
The tensile strength (~c) of the composite
material produced from the fibers and the plastic matrix
is expressed by the following equation.
~c = ~fVf ~ ~MVM
In which
~c the tensile strength of the composite
material
~ f: the tensile strength of the fibers
M^ the tensile strength of the matrix
Vf: the volume percent of the fibers
VM: ~he volume percent of ~he matrix
~s shown by the above equation, the strength Qf the
composite material becomes larger as the volume per-
centage of the fibers in the composite material becomes
larger. Accordingly to produce a composite material
having high strength, the proportion of the volume of the
inorganic fibers to be combined must be increased.
However, if the volume proportion of the inorganic fibers
exceeds 80 ~, the amount of the plastic matrix corres-
pondingly decreases, and it is impossible to fill the
interstices of the hybrid fibers sufficiently with the
plastic matrix. As a result, the composite material
20 produced does not exhibit the strength shown by the above
equation. If ~he volume proportion of the fibers is
decreased, the strength of the composite material cor
respondingly decreases as shown by the above equation.
To produce a practical composite material, it is
25 necessary to combine at least 10 % of the fibers. In
the production of fiber-reinforced plastic composite
materials, the volume proportion of the fibers to be
combined is preferably 10 to 80 %, especially preferably
30 to 60 ~.
The various mechanical properties in the pre-
sent specification are determined by the following
measuring methods.
(a) Interlayer shear strength
In the testing method for determining inter-
35 layer shear stress, a composite material containing
fibers ~10 x 12 x 2 mm) oriented monoaxially is placed on
two pins ~length 20 mm~ having a radius of curvature of
Ç mmO By using a presser with its tip having a radius of
curvature of 3OS mm, the composite material was compres-
sed and the so-called 3 point bending test was carried
out, ancl its interlayer shear stress is measured, and
expressed as shear stress ~kg/n~m2~.
(b) Tensile strength and tensile modulus in
a direction perpendicular ~o the fibers
A composite material, 2 mm ~hick, reinforced
monoaxially with fiber~ was produced~ and a test piece,
19 x 127 mm, was taken from it 50 that the axial direc-
tion of ~he test piece became perpendicular to the
direction of the fiber arrangement. The test piece had a
thickness of 2 mm. A curvature of 125 mmR was provided
in the thickness direction at the centeral portion of the
test piece was finished in a thickness o~ about 1 ~m.
The pulling speed was 1 mm/min., and the tensile strength
(kg/mm2) and tensile modulus (t/mm2) were determined.
(c~ Flexural strength and flexural modulus
in a direction perpendicular to the fibers
A composite material, 2 mm thick, reinforced
monoaxially with fibers was produced, and a test piece,
12.7 x 85 mm, was taken from it so tbat the axial direc-
tion of the test piece became perpendicular to the
direction of the fiber arrangement. The test piece had a
thickne~s of 2 mm. A curvature of 125 mmR was provided
in the thickness direction at the centeral portion of the
test piece was finished in a thickness of about 1 mm.
The test piece is subjected to a 3-point bending tes~,
and the flexural strength (kg/mm2) and the flexural
modulus (t~mm~) are determined.
The interlayer shear strength, the tensile
strength in the direction perpendicular to the fibers and
the flexural strength in the direction perpendicular ts
the fibers are indices showing the strength of ~onding
between the matrix and the fibers.
~ 3~
- 33
(d~ Tensile strength and tensile modulus
A composite material, 2 mm thick, reinforced
monoaxially with fibers was produced, and a test piece,
12.7 x 85 mm, was taken from it so that the axial direc-
tion of the test piece became perpendicular to thedirection of the fiber arrangementO ~he test piece had a
thickness of 2 mm. A curvature of l25 mmR was provided
in the thickness direction at the centeral portion of the
test piece was finished in a thickness of about 1 mmO
The pulling speed was 1 mm/min., and the tensile strength
(kg~mm2) and tensile modulus (t/mm2~ were determined.
~e) Flexural strength and 1exural modulus
A composite material, 2 mm thick, reinforced
monoaxially with fibers was produced, and a test piece,
12~7 x 85 mm, was ~aken from it so that the axial direc-
tion of the test piece became perpendicular to the
direction of ~he fiber arrangement. The test piece had a
thickness of 2 mm. A curvature of 125 mmR was provided
in the thickness direction at the centeral portion of the
test piece was finished in a thickness of about 1 mm.
The test piece was subjected to a 3-point bending test,
and the flexural strength (kg/mm2) and the flexural
modulus (t/mm2) were determined.
(ft Flexural impact value
Flexural impact value was measured by the
Charpy testing method (JIS R7111) by three-point bending.
The result wa~ expressed by flexural impact value (kg-cm/
cm2)
The flexural impact value is an index repre-
senting the strength of bonding between the plastic and
the fibers, particularly an index representing the
strength of resistance to instantaneous impact. If the
flexural impact value is low, the resin is liable to
separate from ~he fibers, and destruction is liable to
occur owing to instantaneous impact.
The above plastic composite material has
- 34 -
a~ an in~erlayer shear ~trength oE at least
8.5 k9JMm 9
b~ a tensile ~trength in a direction perpen-
dicular to the fibers of at least 6 kg/mm~
c) a flexural modulus in a direction perpen-
dicular to the fibers of at least 8 kg/mm2, and
d~ a flexural impact va:lue of at least 200
kg-cm/cm2.
Since the fibers of this inYention have ex-
cellent wetting property with respect to the plastics,
the fiber-reinforced plastic composite material sf this
invention does not particularly require surface-treatment
of the fibers and has excellent strength of bonding
between the fibers and the plasticO Accordingly, the
present invention provides a composite material having
excellent interlayer shear strengtht tensile strength
in a direction perendicular to the fibers, a flexural
strength in a direction perpendicular to the fibers, and
flexural impact value.
Since the fibers of this invention contain
carbon in which the crystals are oriented, they have
higher elasticity than amorphous inorganic fibers.
Accordingly, plastic composite materials reinforced with
the fibers of this invention have excellent tensile
modulus and flexural modulus~
The fibers of this invention are produced at
lower costs than conventional silicon carbide fibers
because the use of an expensive organic silicon compound
i.s decreased.
The fibers of this invention have an excellent
reinforcing effect in plastic composite materials. The
resulting reinforced plastic compssite materials have
excellent mechanical properties and can withstand in a
severe environment over long periods of time. Hence,
they can be used in ap~licat.ions in which conventional
inorganic fiber-reinforced plastic composite materials
ir~
-- 35 --
cannot be used satisfactorily. ~or example, such rein-
f~rced materials can be used as building materials,
materials for aircraft and space exploiting devices,
materials for ships and boatsS materials for land
transpor~ation machines and devices~ and materials for
acoustic machines and devices.
The first or second fibers of the invention may
be hybridized with fibers selected from the group con-
sisting of the fibers of the invention, carbon fibers,
glass fibers, boron fibers, alumina fibers, silicon
nitride fibers, aramid fibers, silicon carbide fibers,
silicon carbide fibers having carbon as a core and
Si-M-C-~ fibers (M=Ti or Zr3 having carbon as a core, and
the resulting hybrid fibers may be used to reinforce
plastic composite materials. The proportion of the
fibers of this invention in the hybrid fibers is at least
10 %, preferably at least 20 %. If the proportion is
lower than 10 ~, the hybrid fibers have a reduced im-
proving effect in respect of the strength of bonding
2~ between the fibers and the plastic~ the reinforcing
efficiency or the mechanical properties such as fatigue
strength. In other words, the hybrid fibers have a
reduced improving effect on interlayer shear strength,
flexural impact value and fatigue strength.
The states of hybridization of the hybrid fibers
are ~1) interhybridization achieved by lamination of a
layer of a certain kind of fibers and a layer of another
kind of fibers, and (2) interlayer hybridization achieved
by hybridization within one layer, which are basic~ and
there are ~3) combinations of these. The main combina-
tions are of the following 6 types.
(a) Lamination of single layer tapes (alternate
lamination of layers of dissimilar fibers)
~ b) Sandwich-type (lamination of dissimilar
layers in a sandwich form)
(c) Rib reinforcement
- 36 -
(d) Lamination of mix-wover1 tows (hybridization
of dissimilar monofilaments)
(e) Lamination of mix~woven tapes ~hybridiza--
tion of dissimilar yarns within a layer~
~f) Mix woven surface layer
Plas~ic composi~e ma1:erials reinforced with
these hybrid fibers have the same excellent advantages as
the above-described composite materials.
Fiber-reinforced composite materials including
ceramics as a matrix:
~ sth the first and second fibers of this
invention described above may be used as the reinforcing
fibers.
These fibers may be directly oriented in the
monoaxial or multiaxial directions in the matrix.
Alternatively, they may be used as woven fabrics such as
a plain weave fabric, a satin weave fabric, an imitation
gauze fabric~ a twill fabric, a helical weave fabric, or
a three-dimensionally woven fabric, or in the form of
chopped fibers.
Carbides, nitrides, oxides~ or glass ceramics,
for example, may be conveniently used as the ceramics.
Examples of the carbide ceramics that can be used include
silicon carbide, titanium carbide, zirconium carbide,
vanadium carbide, niobium carbide, tantalum carbide,
boron carbide, chromium carbide~ tungsten carbide and
molybdenum carbide. Examples of the nitride ceramics are
silicon nitride, titanium nitride, zirconium nitride,
vanadium nitride, niobium nitride~ tantalum nitride,
boron nitride, aluminum nitride and hafnium nitride.
Examples of the oxide ceramics include alumina~ silica,
magnesia, mulite and corierite. Examples of the glass
ceramics are borosilicate glass, high silica glass and
aluminosilicate glass. In the case of using these
ceramic matrices in ~he form of a powder, the powder is
advantageously as fine as possible and at most 300 micro
meters in maximum particle diameter in order to better
the adhesion of the ceramics to the fibers.
The proportion of the fibers of this invention
mixed in the matrix is preferably 10 to 70 % by volume.
If the above mixing ratio is less than 10 % by volume,
the reinforcing effects of the fibers does not appear
sufficiently. If it exceeds 70 %, the amount of the
ceramics is small 50 that the interstices of the fibers
cannot be filled sufficiently with the ceramics.
In the production of the ceramic composite
materials, it is possible to use a binder (sintering aid)
for sintering the powdery ceramic matrix to a high
density and/or a binder for increasing the adhesion of
the powdery ceramic matrix to the fibers.
The former binder may be ordinary binders used
at the time of sintering the carbide~ nitride, oxide and
glass ceramics For example, boron, carbon and boron
carbide may be cited as a binder for silicon carbide.
Examples of binders for silicon nitride are aluminum
oxide, magnesium oxide, yttrium oxide and aluminum oxide.
Preferred examples of the latter hinder include
organic silicon polymers such as diphenylsiloxane~
dimethylsiloxane, polyborodiphenylsiloxane, polyboro-
dimethylsiloxane, polycarbosilane, polydimethylsilazane,
polytitanocarbosilane and polyzirconocarbosilane, and
organic silicon compounds such as diphenylsilanediol and
hexamethyldisilazane.
The binder for increasing the adhesion of the
powdery ceramic matrix to the inorganic fibers, when
heated, is converted mainly into SiC or Si3N4 which
reacts on the surface of the powdery ceramic matrix to
form a new carbide, nitride or oxide. Consequently, the
adhesion of the powdery ceramic matrix to the inorganic
fibers becomes very superior. These organic silicon
compounds or polymers, like the ordinary binders, act to
increase the sinterability of the powdery ceramic matrix.
- 38 -
Accordingly~ the addition of these binder6 is very ad-
vantageous to the production of composite materials
having high strength. Where a strong adhesion between
the powdery ceramic matrix and the fibers can be ob-
tained~ it is not necessary to add binders.
The amount of the binders may be one s-uficient
for producing an effect of the additionO
Usually, it is preferably 0O5 ~o 20 % by
weigh~ based on ~he powdery ceramic matrix.
The ceramic composite materials reinforced with
the fibers of this invention can be produced, for exmple,
by the following methods.
There are various methods of obtaining ag
gregates of the powdery ceramic matrix and the ibers.
The aggregate can be obtained relatively easily, par-
ticularly by embedding the fibers in a rnixture sf the
powdery ceramic matrix or ceramics and a binder, a method
of alternatingly arranging the fibers and the powdery
ceramic matrix or the above mixture, or a method com-
prising arranging the fibers, and filling the intersticesof the fibers with the powdery ceramic matrix or the
above mixture.
Sintering of the aggregates may be effected,
for example, by a method comprising compression molding
the aggregate by using a rubber press, a mold press, etc.
under a pressure of 50 to S,000 kg~cm2, and sintering the
resulting molded product in a heating furnace at 800 to
2400 C, or by a method which comprises sintering the
aggregate at a temperature of 800 to 2400 C by hot
pressing while it was compressed under a pressure of 50
to 5,000 kg/cm2.
The above sintering methods may be carried out
in an atmosphere, for example an inert gas as nitrogen,
argon, carbon monoxide or hydrogen or in vacuum.
As shown in Example 102, in the production of
the above fiber-reinforced ceramic composite material, a
- 39 -
precursor of the ibers (precursor fibers before curing
may be used instead of the fibers~
By subjec~ing the result:iny sintered composite
ma~erial to a series of treatments to be described below
at least once, a sintered body having a higher density
can be obtained SpecificallyD a sintered body having a
higher density can be obtained by a series of treatments
o~ immersin~ the sintered body under reduced pressure in
a melt of th2 organic silicon compound or polymer, or if
desired, in a solution of the above compound or polymer
to impregnate the melt or solution in the grAin boun-
daries and pores of the sintered body, and heating the
sintered ~ody after impr~gnati~n. The impregnated
organic silicon eompound of polymer changes mainly into
SiC or Si3N4- They exist in the brain boundaries and the
pores of the composite sintered body. They reduce the
cores and at the same time, form a firm bond in the
ceramic matrix, and thus increases the mechanical
strength of the product.
The mechanical strengh of the resulting
sintered body may also be increased by coating the
organic silicon compound or polymer either as such or a
solution of it in an organic solvent to clog the pores,
or by coating it on the surface of the sintered product
2S and then heat~treating the coated sintered body by the
same method as above.
The organic solvent which may be used as
required ma~ be, for example, benzene~ xylene~ hexane,
ether, tetrahydrofuran, dioxane, dchloroform, methylene
chloride, ligroin, petroleum ether, petroleum benzine,
dime~hyl sulfoxide and dimethylformamide~ The organic
silicon compound or polymer is dissolved in the organic
solvent and can be used as a solution having a lower
viscoci~yO
The heat-treatment is carried out at 800 to
2400 C in an atmosphere of at least one inert gas
-- ~10 --
selected from ni~rogn, argon and hydrogen or in vaccum.
The serie~ of impregnation or coating opera-
tions may be repeated any numbe!r of times so long as
these operations are possible~
In the production of the fiber-reinforced
ceramic composite material, the form of the starting
ceramic and the method of producing the composite are not
to be limited to those described above, and ordinary
forms and methods used may be employed without any in-
C~nvenienceo
For example, a fine powder obtained b~ the
sol-gel method and a precursor polymer convertible to the
ceramics by pyrolyæing may be used as the starting ceramics.
When the reinforcing fibers are short ~ibers, injection
molding, extrusion molding and casting may be e~ployed as
the molding method. By jointly using ~IIP (hot isostatic
pressing) in pyrolyzing, the performance of the composite
material may be increased. On the other hand, excellent
composite materials may also be obtained by vapor-pha~e
methods such as CVD and CVI.
The fracture toughness, KIC, of the ceramic
composite material to that of the matrix alone containing
no fibers is about 2 to 7, and the ceramic composite
material has a reduction rate sf flexural strength ~to be
referred to as a "flexural strength reduction rate"),
measured by a thermal shock fracture resistance method,
of less than ~bout 10 %.
The fracture tnughness (KIC) is measured by the
IF method tIndentation Fracture ~lethod) described in J.
Am. Ceram. Soc. 59, 371, 1976) oE A~ G. EvanO
The flexural strength reduction rate is deter-
mined Erom the flexural strength of a sample (obtained by
heat-treating a piece, 3 x 3 x 30 mm, cut out from the
ceramic composite material at a temperature of 800 to
1,300 C in air or nitrogen for 20 minutes, immediately
then immersing it in water at 25 C, and then drying it)
~ 3~3~
measured by a three~point flexural strength testing
method, and that oE the ceramic: composite material not
subjected to the above heat-treatment~
The initial rate of f`iber degradation induced by
reaction to be simply referred to as the "degradation
rate" is determined as follows:
The inorganic fibers, silicon carbide fibers or
alumina fibers are embedded in the po~dery cera~ic matrix
and then heated in an argon atmosphere at a predetermined
temperature (the temperature use~ at the time of produc-
ing the composite material) for S minutes. The fibers
are then takerl out, and their tensile strength is mea
sured. The difference between the measured tensile
strength and the tensile strength of the fibers before
the treatment is divided by the heating time ~seconds)~
and the quotient i6 defined as the above "degradation
rate" .
As compared with conventional ceramic composite
materials reinforced with carbon fibers, the above
ceramic composite material can be used at high tem-
peratures in an oxidizing atmosphere. Furthermore, as
compared with ceramic composite materials reinorced with
other fibers, the increase of KIC in the above eeramic
composite material greatly improves the inherent brit-
tleness or the inherent nonuniformity of mechanicalstrength of the above ceramic composite material.
Accordingly it is suitable for use as a structural
material. The improvement of high temperature impact
strength enables the above ceramic matrix composite
material to be used in an environment where vaeiations in
temperature from high to low temperatures are great. The
fibers of this invention are stable to the ceramic as a
matrix, and fully achieves the inherent purpose of rein-
forcement with fibers.
Fiber-reinforced composite materials including
carbon as a matri~-
- 42 -
~ oth the first and the second fibers of this
invention can be used as the re!inforcing fibers.
These fibers may be dlirectly oriented in the
monoaxial or multiaxial di~ections in the matrix.
Alternatively~ they may be used in woven fabrics such as
a plain weave fabric~ a satin weave fabric, an imita~isn
gauze fabric, a twill fabric, a helical weave fabric, or
a three-dimensionally woven fabric, or in t.he form of
chopped fibers.
The proportion of ~he fibers of this invention
mixed in the matrix is preferably 10 to 70 ~ by volume~
If the above mixing ratio is less than 10 % by volume,
the reinforcing effects of the fibers does not appear
sufficiently. If it exceeds 70 %, the amount of the
ceramics is small so that it is difficult to fill the
interstices of the fibers sufficiently with the ceramics.
Carbonaceous material for matrices of ordinary
C/C composites may be used as materials for matrices of
the above composite materials. Examples include mate-
rials which can be converted to carbon by pyrolyzing, forexample, thermosetting resins such as phenolic resins and
furan resin, and thermoplastic polymers such as pitch,
moldable materials such as carbon powder or a mixture of
carbon powder and the above resins. When carbon powder
25 is used as a carbonaceous material for matrix, the use of
a binder is more effective for increasing the adhesion of
the matrix to the fibers.
Examples of the binder are organic silicon
polymers such as diphenylsiloxane~ dimethylsiloxane,
polyborodiphenylsiloxane, polyborodimethylsiloxane,
polycarbosilane, polydimethylsilazane, polytitano-
carbosilane and polyzirconocarbosilane and organic
silicon compounds such as diphenylsilanediol and hexa-
methyldisilazene.
The aggregate of the carbonaceous material and
the fibers may be molded, for example, by a method com-
r
~ ~3 ~
prising carbon powder optionally containing ~he binder to
the reinfocing fibers, and moldiny the m.ixture by using
a rubber press, a mold or a hot press, or a method com-
prising impregnating a so~lution of a ~hermose~ting or
thermcplastic resin in a bundle of the fibers or a woven
fabric of the fibers, drying and removing ~he solvent~
and molding the prepreg sheets by an ordinary method of
molding an ordinary FRP, or a method comprising laminat-
ing prepreg sheets on a mold, and molding them by a hot
1 n press~
The resulting molded article, if required~ isrendered infusible, and then in an inert atmosphere,
heated at 80a to 3000 9C to carbonize the matrix com-
ponentO
The resulting fiber~rein~orced material may
directly be used in various applications. Alternatively,
it may be further repeatedly subjected to a step of
impregnating it with a melt or solution of a thermo-
plastic or thermosetting resin and carbonizing the coated
material to give a higher density and a higher strength.
In particular, where mechanical properties are required,
the density of the material can be effectively increased
by a vapor-phase method such as CVI.
In the fiber-reinforced carbon material ob-
tained, the reinforcing fibers are the fibers of thisinvention having high strength and high modulus~ and have
improved adhesion to the carbon matrix. Accordingly, the
resulting fiber-reinforced carbon material has high
strength, modulus and tenaciousness and also excellent
practical mechanical properties such as abrasion resist-
ance~
Accordingly, the resul~ing composite materials
may advantageously be used in various kinds of brakes and
heat-resistant structural materials.
r-
-- 4~1 --
Fiber-reinforced composite materials including
a sintered body matrix producecl from the polymer com-
position of the invention~-
These composite matelials include a composite
material comprising the first fibers of the invention asthe reinforcing fibers and a carbonized product of the
first polymer composition of the invention as the matrix;
a composite material comprising the first ibers of the
invention as the reinforcing fibers; and a carbonized
1~ product of the second polymer composition of the
invention as the matrix; a composite material comprising
the second fibers of the invention as the reinforcing
fibers and a carboni~ed product of the first polymer
composition of the invention as the matrix; and a com-
posite material comprising the second fibers of theinvention as the reinforcing fibers and a carbonized
product of the second polymer composition of the
invention as the matrix.
To describe these composite materials com-
prehensively, the ~first and second" qualifying thefibers and the polymer compositivns will be omitted
hereinafter~
A fiber-containing molded ar~icle is produced
by, for example, a method comprising adding a powder of
the polymer composition to a fabric of the fibers such as
a plain weave fabric, a satin weave fabric, an imitation
gauze fabric, a twill fabric, a helical woven fabric or a
three-dimensionally woven fabric~ a method comprising
impregnating the fabric with a solution or slurry of the
polymer composition, remo~ing the solvent, drying the
impregnated fabric, and heat-molding the prepreg sheet,
or a method comprising melt-kneading the short fibers or
chopped fibers with the polymer composition and molding
the mixture by compression or injection molding. At this
time~ the content of the fibers in the molded article is
preferably 10 to 70 % by volume~ The polymer composition
r~
- ~5 --
of this invention as such may be used in this stepO
However~ since it is not necessary ~o flberize the
polymer composi~ion further, thle ratio o~ silicon to
carbon may be set within a slig;htly broader range than in
the case o the composition of this invention.
The proportions of khe optically isotropic
pitch used may be adjusted to llD to 4,900 parts by weight
per 100 parts by weight of the organic silicon polymer~
The proportion of the mesophase pitch may be adjusted to
5 to 50,000 parts by weight per 100 parts by weight of
the reacti.on product of the organic sil.icon polymer and
the isotropic pitch.
In the production of the fiber-containing
molded article, the polymer composition may be used as a
mixture of it with a calcined inorganic powder obtained
by pyrolyzing the polymer composition at 800 to l,OD0 C in
an inert atmosphere.
This calcined powder preferably consists es-
sentially of 0~01 to 69.9 ~ of Si, 2~.9 to 99.9 % of C
and 0.01 to 10 % of O if it does not contain a transition
metal compound. If it contains a tansition metal, it
preferably consists essentially of 0.005 to 30 ~ of the
transition metal, 0.01 to 69.9 ~ of Si, 29.9 to 99~9 ~ of
C and 0~01 to 10 % of O.
Then, as required, the product i5 subjected to
a curing treatment.
The methods of curing in the production of the
fibers o this invention may be directly used to perorm
this treatment.
The molded article rendered infusible is
pyrolyzed at a temperature of 800 to 3~000 C in vacuum
or in an inert gas to give a composite material contain-
ing a matrix composed of carbon, silicon and oxygen,
which is carbonized and fiber-reinforced.
It is presumed that in the process of heating,
carboniz~tion begins to be vigorous at about 700 C, and
P
- 46 --
is nearly ~ompeleted at about 800 C. It is preferred
therefore to perform pyrolyzing at temperatures of 800 QC
or above. To obtain temperaturles higher than 3 r C
requires expensive equipment, and pyrolyzing at high
temperatures above 3,000 ~ is not practical from the
viewpoint of cost.
The step of curing ma~y be omitted by greatly
decreasing the temperature-elevation rate for carbo-
nization in this step or by using a shape retaining jig
for the molded article, or a shape retaining means such
as a powder head. By performing the molding with a high
temperature hot press, a high-density composite can be
obtained in one step.
The fiber-reinforced carbonaceous composite
material obtained by pyrolyæing and carbonization con-
tains some open pores. If re~uired, it may be im-
pregnated with a molten liquid, solution or slurry of the
polymer composition and then pyrolyzed and carbonized
after optionally it is cured. This gives a composite
haviny a higher density and higher strength. The im-
pregnation may be effected by any oE the molten liquid,
solution and slurry of the polymer composition. To
induce permeation into fine open pores, after the com-
posite material is impregnated with the solution or
slurry of the polymer compositionr it is placed under
reduced pressure to facilitate permeation into the fine
pores. Then, it is heated while evaporating the solvent,
and subjected to a pressure of 10 to 500 kg~mm2. As a
result, the molten liquid of the polymer composition can
be filled in the pores.
The resulting impregnated material can be
cured, pyrolyzed and carbonized in the same way as above~
By repeating this operation 2 to 10 times, a fiber-
reinforced composite material having a high density and
high strength can be obtained.
This fiber-reinforced carbonaceous composite
- ~17 ~
material is characteY:ized by having high strength, high
modulus of elasticity and excellent tenaciousness since,
the reinforcing fibers have high streng-~h and modulus of
elasticity, and improved adh2sion to the carbon matrix.
F~rthermore, it has excel~ient oxidation resist~
as~ce and abrasion resistance attributed to the efect of
the siliicon carbide component contained in the fibers
and the matri~O Accordingly, this composite material
have excellent mechanical properties~ oxidation resist-
ance and abrasion resistance~ and is useful as various
~ypes o~ brakes and thermally resistant structural
materials~
Fiber-reinforced composite materials including
a metal as a matrix:-
The first and second fibers of this invention
may he used directly as the reinforcing fibers. They may
also be used as fibers to which at least one adhering
material selected from the group consisting of fine
particles, short fibers and whiskers of thermally resist-
ant materials.
First, a method of adhering at least one ad-
hering material selected from the group consisting of
fine particles, short ~ibers and whiskers of thermally
stable materials to the surface of the fibers of this
invention provided as continuous filaments will be
described.
Examples of the thermally stable materials are
metals, ceramics and carbon.
Specific examples of the metals as the
thermally stable materials are steel, stainless steelt
molybdenum and tungsten. Specific examples of the
ceramics include carbides such as SiC, TiC~ WC and B4C,
nitrides such as Si3N~, BN and AlN, borides such as TiB2
and ZrB2 and oxides such as A12O3, B2O3, MgO, ZrO2 and
SiO2. Other examples of the ceramics include poly-
carbosilane compositions, polymetallocarbosilane com-
- ~8 -
positions, and cal~ination produc-ts of the first and
~econd polymer compositions of this invention.
The forrn of the adhering material differs
depending upon the combination of it with the continuous
inorganic filaments or the required properties. The
short fibers or whiskers of the adhering material desir~
ably have an average particle diameter 1/3~000 to 1/5 of
that of the continuous filaments and an aspect ratio of
from 50 to 1,000. The fine particles desirably have an
average diameter 1/5,000 ts 1/2 of that of the continuous
fibers.
The amount of the adhering material to be
applied to the continuous fibers differs depending upon
the properties of both, and the use of the fiber-rein-
forced composite produced~ In the case of using it forfiber-reinforced metals, the volume ratio of the adhering
material based on the continuous filaments is preferably
about Ool to 500 %.
The adhering materials may be used singly or in
combination. For example, when the fibers of this inven-
tion are to be used for reinforcing Al containing Co, Si,
Mg and Zn, it is especially preferable to apply the fine
particles to the neighborhood of the surface of the
continuous fibers and apply the short fibers and/or the
whiskers to the outside of the fine particles in order
to prevent microsegregation of the added elements on the
surface of the continuous filaments. In this case, the
suitable ratio of the fine particles to the short fibers
and/or the whiskers is from 0.1:5 - 40:1.
It is preferred to immerse the continuous
filaments in a su~pension of the adhering material be-
cause it is simple and has a wide range of application.
Figure 1 shows one example of the outline of an
apparatus used in the production of the above fibers.
A bundle 4 of continuous filaments (a woven
fabric from the contilluous filament bundle may be used
~C
- ~9 -
instead of the continuous filament bundle~ wound on a
bobbin 5 is unwound, conducted by movable rollers 6 and
7, and passed through a liquid 3 in which the adhering
material is suspended. Then, it is pressed by press
rollers 8 and 9 and wound up on a bobbin 10. In the
resulting filament bundle or fabric, the adhering
material adheres to the surface of every individual
continuous filament~ There may be one treating vessel 1
containing a treating liquor 3. For various modiEied
methods~ two or more tgeating vessels containing treating
liquors of different compositions respectively may be
used.
To promote the adhesion of the adhering
material to the continuous filaments, ultrasonic vibra-
tion 2 may be applied to the treating liquor 3. In thecase of applying two or more kinds of the adhering
material to the continuous filaments~ the treating liquor
may be a suspension of the fine particles and the short
fibers and/or whiskers, or it is possible to use two
treating vessels one containing a suspension of the fine
particles as the treating liquor and the other containing
a suspension of the short fibers and/or whiskers as the
treating liquor. In the latter case, the sequence of
immersing the continuous filament bundle or the woven
fabric may start with the suspension of the fine par-
ticles or the suspension of the short fibers and~or
whiskers.
Since the fibers having the adhering material
are composed of a continuous filament bundle in which the
adhering material adheres to the surface of every in-
dividual filament of the invention having high strength
and high modulus of elasticity, these continuous fila-
ments can be uniformly dispersed in the composite
material, and the volume ratio of the fibers can be
controlled to a very broad range. Furthermore, the
contact among the continuous filaments decreases, and the
r.~ r~3
- 50 -
resulting composite material has a uniform composition~
This brings about the advantage of improving the
mechanical properties such as strength of the composite
material~
The reinforcing fibers may De applied to the
matrix by, for example, arranging the fibers themselves
in the monoaxial or multiaxial direction, or used in the
fvrm of various woven fabrics such as a plain weave
fabric, a satin weave fabric, an imitation gauze fabric
a twill fabric, a helical woven fabric or a three-
dimensionally woven fabric, or in the form of chopped
fiber, to give the composite material of this invention.
Metals that can be used in this invention may
be, for example, aluminum, aluminum alloys, magnesium,
magnesium alloys, titaniuum, and titanium alloys.
The mixinq proportion of the reinforcing fibers
in the matrix is preferably 10 to 70 % by weight.
The composite material can be produced by the
following methods of producing ordinary fiber-reinforced
metal composite materials. There are (1) a diffusion
bonding method, (23 a melting permeation method, ~3) a
flame spraying method, (4~ an electrolytic deposition
method, (5) an extrusion and hot roll method, (6) a
chemical vapor-phase deposition method, and (7) a
sintering method.
tl) According to the diffusion bonding method,
a composite material of reinforcing fibers and a matrix
metal can be produced by aligning the reinforcing fibers
and wires of the matrix metal alternately in one direc-
tion, covering the upper and lower suraces of the ar-
rangement with a thin coating of the matrix metal, or
covering only the lower surface of it with the above thin
coating and the upper surface of it with a powder of a
mixture of the matrix metal and an organic binder to form
a composite layer, laminating a plurality of such com-
posite layers, and consolidating the laminate under heat
and pressure.
The organic binder desirably volatili~es and
dissipate6 before it is heated to a temperature at which
i~ forms a carbide with the matrix metalO For example,
CMC, paraffins, resins and mineral oils may be used.
Alternatively, the colmposit2 material may also
be produced by bonding and coating a mixture of the
matrix metal powder and the organic binder to the ~ur-
faces of the reinforcing fibers, aligning and laminating
a plurality of layers of such fibers, and consolidating
the laminate under heat and pressure.
~ 2) According to the melting permeation
method, the composite material can be produced by filling
the interstices of tbe aligned reinforcing fibers with
molten aluminum, aluminum alloy, magnesium, magnesium
alloy, titanium or titanium alloy. Since the wettability
of the metal-coated fibers with the matrix metal is good,
the interstices of the aligned fibers can be filled
uniformly with the matrix metal.
(3) According to the flame spraying method, a
tape-like composite material can be produced by coating
the matrix metal on the surface of aligned reinforcing
fibers by plasma flame spray or gas flame spray~ It may
be used directly, or a plurality of the tape-like com-
posite materials are laminated and subjected to the
diffusion bonding method ~1) to produce a composite
material.
~ 4) According to the electrolytic deposition
method, a composite material can be produced by electro-
lytically depositing the matrix metal on the surface of
the reinforcing fibers, laminating a plurality of the
composite materials, aligning them, and subjecting tbe
lamination to the diffusion bonding method ~1).
~ 5) According to the extrusion and hot roll
method, a composite material can be produced by aligning
the reinforcing fibers in one direction, sandwiching the
aligned reinforcing fibers between foils of the matrix
t~
metal 7 optionally passing the sandwich structure between
heated rolls to bond the Eibers and the matrix metal.
(6~ According to the chemical vapor deposition
method~ a composite material can be produced by placing
the fibers in a heating furnace, introducing a gaseous
mixture of~ for example~ aluminum chloride and hydrogen
to thermally decompose the gas to deposit aluminum metal
on the surface of the fibers, and laminating the metal-
deposited fibers, and subjecting the laminate to the
diffusion bonding method (1).
~ 7~ According to the sintering method~ a
composite material can be produced by filling a powder of
the matrix metal in the interstices of aligned fibers~
and sintering the resulting product under pressure or
without pressure.
The tensile strength (~) of the composite
material produced from the inorganic fibers and the metal
matrix is represented by the above equation (see the
above description on the composite material including a
plastic matrix).
As shown by the above equation, the strength of
the composite material becomes higher as the volume
proportion of the reinforcing fibers in the composite
material becomes larger. Hence, to produce a composite
material having high strength, it is necessary to
increase the volume proportion of the reinforcing fibers~
However, if the volume proportion of the reinforcing
fibers exceeds 70 %, the amount of the metal matrix is
small so that the intersices of the reinforcing fibers
cannot be fully filled with the metal matrix. Hence, the
composite material produced cannot exhibit the strength
shown by the above equation. If the volume proportion of
the reinforcing fibers in the composite material is
decreased, the strength of the composite material de-
creases as shown by the above equation. To obtaina composite material having practical utility, it is
- 53 --
mecessary to combine at least 10 % of the reinforcing
fibers~ Accordillgly, if the voLume proportion of the
reinforcing fibers is limited to 10 to 70 ~ by volume in
the production o the fiber-reillforced metal composite
material 9 the best result can be obtained~
In the production oE the compositc material, it
is necessary to heat the metal to a temperature near the
melting point or a higher temperature as stated above,
and combine it with the reinforcing fibers. Thus9 the
reduction of fiber strength by the reacion of the rein-
forcing fibers with the molt~n metal gives rise to a
problem. But when the fibers of this invention are
immersed in the molten metal, the abrupt degradation seen
in ordinary carbon fibers is not observed, and therefore,
a composite material having excellent mechanical strength
can be obtained.
The methods of measuring the various mechanical
properties used in this invention will be described.
(a) Initial rate of degradation induced by
2n reaction
tl~ In the case of metals and alloys having
a melting point of not more than 1200 C
The fibers are immersed for 1, 5, 10, and 30
minutes respectively in a molten metal heated to a tem-
perature 50 C higher than the melting point of the
metal. Then, the fibers are extracted, and their tensile
strength is measured. From the results obtained, a
reaction degradation curve showing the relation between
the immersion time and the tensile strength of the fibers
is determined. From a tangent at an immersion time of 0
minute, the initial rate of degradation induced by reac-
tion tkg~mm2-sec 1) is determined.
(2) In the case of metals and alloys having
a melting point higher than 1200 ~C
The fibers are laminated to a metal foil~ The
laminate is placed under vacuum, heated to a ternperature
-- 5~ --
of (the melting point of the metal foil) x (0.6-0.7), and
maintained under a pressure of 5 kg/mm2 for 5, 10, 20 and
30 minutes~ respectivelyD Then, the fibers are extracted,
and their tensile streng~h is measured~
From the results, the ini~ial rate of degrada-
tion induced b~ reaction is detlermined by the same pro-
cedure as in (1).
(b) Ratio of fiber strength reduction
The fiber strength at an immersion time and a
maintenance time sf 30 minutes in (a) above is deter-
mined. The ratio of fiber strength reduction is cal-
culated by dividing (the initial strength - the fiber
strength determined abovej by the initial strength.
The initial rate of reduction by reaction shows
the degree of the reaction between the fibers and the
matrix in the production of a fiber-reinforced metal
within a short time~ The smaller this value~ the better
the affinity between the fibers and the matrix and the
larger the fiber reinforcing effect.
(c) Interlayer shear strength test
The same as the method described above with
respect to a composite material comprising plastics as a
matrixO
~d) Fatigue test
A round rod (10 mm in diameter x 100 mm in
length) is produced from a composite material in which
the inorganic fibers are aligned monoaxially. The axial
direction of the composite material is the longitudinal
direction of the rod~ The rod is worked into a tes~
specimen for a rotational bending fatigue test. The
specimen is subjected to a rotational bending fatigue
test with a capacity of 1.5 kgm, and its fatigue strength
after 107 times is measured and defined as the fatigue.
The ratio of the fatigue strength and the
tensile strength is an index showing the strength of
bonding between the matrix and the fibers.
- 55 -
Since the degradation of the fiber strength due
to the reaction with the molten metal is little in the
fibers of this invention, the fiber-reinforced ~etal
composite materials including the fibers of this
inventioll have excellent tensile strength and other
mechanical properties, high modulus of elasticity and
excellent thermal resistance and abrasion resistance.
Accordingly, they are useful as various material in
various technological fields such as synthetic fibers,
synthetic chemistry, machine industry, construction
machinery, marine and space exploitation~ automobiles and
f oods~
According to this invention, a carbonized
sintered body can be produced from a polymer composition
by the following procedure.
Examples of the polymer composition that can be
used at this time are the first and second polymer com-
positions of the inventi~n~ and polymer compositions
having a slightly broader chemical composition than the
polymer compositions of this invention, which are de-
scribed with reEerence to the description of fiber-
reinforced composite materials comprising a carbonized
product of the polymer composition of the invention as a
matrix.
The polymer composition or a mixture oE the
polymer composition and its calcination product is first
finely pulverized, and can be molded by using a method of
molding an ordinary carbonaceous material. The calcina-
tion may be carried out at a temperature of 800 to
30 1300 C.
The molding method can be selected from the
molding methods for ordinary carbonaceous material by
considering shape, size, use of the molded product and
the productivity of molding. For example, for production
oE articles of the ~ame shape with good productivity, a
dry mold press method is suitable. To obtain molded
- 5~ -
articles of a slightly complex shape7 an lsostatic mold-
ing method ~rubber press molding method) is suitableO
For molding a molten mass of the above polymer, a hot
press molding method, an injection molding method and an
extrusion molding method are suitable.
In the case of molding the mixture of the
polymer composition and its calcination product, the
proportions of th2 polYmer composition and its calcina-
tion product may be properly determined by considering
the shape, use and cost of the molded article to be
obtained.
The molded article is then subiected to an
curing treatment.
A typical method of curing is to heat the
molded article in an oxidizing atmosphere. The curing
temperature is preferably 50 to 400 ~C~ If the curing
temperature is excessively low, bridging of the polymer
does not take place. If this temperature is excessively
high r the polymer burns.
The purpose of curing is to render the polymer
constituting the molded article in the three-dimensional
infusible insoluble bridged state and to have the molded
article retain its shape without melting during carbo-
nization in the next step. The gas constituting the
~S oxidizing atmosphere during curing may be, for exampe,
air, ozone, oxygen, chlorine gas, bromine gas, ammonia
gas, or mixtures of these gases.
An alternative method of curing which may also
be used comprises applying gamma-ray irradiation or
electron beam irradiation to the molded article in an
oxidizing or non-oxidizing atmosphere while as required
heating it at low temperatures.
The purpose of gamma ray or electron beam
irradiation is to prevent the matrix from melting and
losing the shape of the molded article by further poly~
merizing the polymer constituting the molded article.
- 57 -
The suitable irradiation dose of yamma rays or
electron beams is 106 to 101 rads.
The irradiation may be carried out in vacuum,
in an inert gas atmosphere or in an atmosphere of an
oxidizing gas such as air, oæone~ o~ygen, chlorine gas,
bromine gas, ammonia gas or mixtures of these.
curing by irradiation may also be carried out
at room temperature. If required, by performing it while
heating at a temperature of 50 to 200 C~ the curing may
be achieved in a shorter period of time~
The molded article rendered infusible is then
pyrolyzed and carbonized at a temperature of 800 to
3000 C in vacuum or in an inert gasO
It is presumed that in the heating process,
carbonization begins to become vigorous at about 700 C,
and is nearly completed at about 800 C. Hence, the
pyrolyzing i5 preferably carried out at a temperature of
at least 800 C. To obtain temperatures higher than
3000 3C, expensive equipment is required. Accordingly,
pyrolyzing at high temperatures higher than 3000 C is
not practical in view of cost.
The curing step may be omitted by making the
temperature elevation rate for carbonization in this step
very slow, or by using a jig for retaining the shape of
the molded ~rticle or a shape retaining means such as a
powder head. Alternatively, by using a high temperature
hot press method in this molding step, the next step may
be omitted.
~s required, the resulting carbonaceous
material may be impregnated with a melt, solution or
slurry of the polymer solution, and pyrolyzed for
carbonization~ This further increases the density and
strength of the carbonaceous material.
For impregnation, any of the melt, solution and
slurry of the polymer composition may be used. To facili-
tate permeation into fine open pores, the carbonaceous
s~ g~
- 58 -
material after impregnation with the solu~ion or slurry
of the polymer composition is placed under reduced pres~
sure to facilitate permeation into the fine pores~ heated
while evaporating the solvent, and pressed under 10 to
5~0 kg/cm2 thereby to Eill the melt of the polymer
composition into the pores.
The carbonaceous material impregnated with the
polymer composition may be cured, pyrolyzed and
carboni~ed in the same way as in the previous step~ By
repeating this operation 2 to 10 times, a carbonaceous
material having high density and high s,rength can be
obtained.
The state of existence of Si, C and O in the
silicon-containing component corresponding to the con-
stituent (iii) of the first fibers in the resultingearbonaceous material can be controlled by the carbo~
nization temperature in the above-mentioned step.
When it is desired to obtain an amorphous
material consisting substantially of Si, C and O, it is
proper to adjust the carbonization temperature to 800 to
1000 C. If it is desired to obtain a material con-
sisting substantially of beta-SiC and amorphous SiOx
(O~x<2), temperatures of at least 1700 C are suitable.
When a mixture of the aggregates is desired,
temperatures intermediate between the above temperatures
may be properly selected.
The amount of oxygen in the carbonaceous
material of this invention may be controlled, for
example, by the curing conditions in the above
3~ curing step.
The state of existence of Si, M, C and O in the
silicon-containing component corresponding to component
~iii) of the second fibers may be controlled likewise~
The resulting carbonaceous material contains a
silicon carbicle component very uniformly dispersed and
integrated in carbon. The presence of this component
~3~
- 59 --
promotes microcrystallization of oarbon at low tem-
peratures, inhibition of consumption of carbon by
oxidation, and the increase of hardness.
The carbonaceous material, therefore, has
excellent mechanical properties, oxidation resistance and
abrasion resistance and can be advantageously used as
vario~s types o~ brakes and thermally stable structural
materials.
Brief Description ~f the Drawing
Figure 1 is an outline view of an apparatus
used for applying thermally stable fine particles to the
surface of the fibers of this invention.
In the following examples, the weight average
molecular weight and the softening point were measured by
the following methods.
The weight average molecular weight (Mw) is a
value dertermined by the following procedure.
If the pitch is soluble in GPC measuring
solvent ~chloroform, T~F or o-dichlorobenzene), it is
dissolved in that solvent, and its molecular weight is
measured by using an ordinary separation column.
The concentration of the sample is not par~
ticularly limited because integration may be carried out
freely. The suitable concentration is 0.01 to 1 ~ by
weight.
On the other hand, when the pitch contains
components insoluble in the above organic solvent, it is
subjected to a hydrogenation treatment under mild
conditions to hydrogenate part of the aromatic rings
without cleaving the carbon-carbon bonds to render it
solvent-soluble. Then, its GPC measurement is conducted.
The hydrogenation method wih lithium and
ethylenediamine described by J. D. Brooks and H.
Silverman ~Fuel, 41, 1962, p. 67-69) is preferred because
the hydrcgenation can be performed under mild conditions
below 100 C.
3~
- 60 -
The results of the GPIC measurement usua-].ly have
a broad distribution, and Mw is determined by ap
proximation to one peak~
The softening point is measured by using a
commercial thermal analysis system,. :Eor e~ample, Metler
FP~oO Ther~osystem~ Specifically, a sample is filled in
a sample cylirld2r having an open pore portion at the
bottom, and heated at a rate of ~ C/min., and the
Elowing of the sample from the pore portion by softenlng
is optically detected, and the softening point is deter-
mined~
- 61 -
EX~MPLES
The following examples illustra-~e the present
inven-tion.
ReEerence Example 1
In a 5-liter three-necked flask were placed 2.5
li-ters of anhydrous ~ylene and 40() g or sodium. The
-Elask inside was heated to the boiling point of xylene in
a nitrogen gas current, and 1 liter oE dime-thyldichloro-
silane was dropped into the flask in 1 hour After the
completion of -the dropping, the flask contents was sub-
jected to reEluxing with heating for 10 hours to form a
precipitate. The precipita-te was collected by filtration
and washed with methanol and water in this order to
obtain 420 g of a polydimethylsilane as a white powderO
400 g of -this polydimethylsilane was fed into a
3-liter three-necked flask provided with a gas-blowing
tube, a stirrer, a cooler and a distillate tube and
subjected to a heat treatment at 420 ~C with s-tirring in
a nitrogen current of 50 ml/min. to obtain 350 g of a
colorless transparent slightly viscous liquid.
The liquid had a number-average molecular
weight of 470 as measured by an osmo-tic pressure method.
The substance, as measured for infrared absorp-
tion spectrum, showed absorptions of Si-CH3 at 650 -
900 cm 1 and 1250 cm 1, Si-H at 2100 cm ~ Si-CH2--Si at
1020 cm~l and 1355 cm~l and C-H at 2900 cm 1 and 2950 cm 1
The substance, as measured for Ear infrared absorption
spectrum, showed an absorption of Si-Si at 380 cm-l~
It was confirmed from the results of NMR analy-
sis and infrared absorption analysis that the aboveorganosilicon polymer was a polymer wherein the ratio of
the total number of tSi-CH2) units to the total number of
(Si-Si) units is about 1:3.
300 g of the above organosilicon polymer was
treated with e-thanol to remove a low-molecular portion to
obtain 40 g of a polymer having a number-average mole-
- 62 -
culer weight of 1200.
This substance was measured Eor infrared absorp-
tion spectrum, which gave the same absorption peaks as
above.
It was confirmed from the results of NMR analy-
sis and inErared absorption analysis that the organo-
silicon pol~mer was a polymer wherein -the ratio oE the
to-tal number of (Si-CH2) units to the total number of
(Si-Si) units was about 7:1.
ReEerence Example 2
High-boiling pe-troleum fractions (gas oil and
heavier Eractions) were subjected to Eluid catalytic
cracking and rectification at 500 C in the presence o-f a
silica-alumina cracking catalyst, and then a residue was
obtained from the rectifier bottom. Hereinaf-ter, this
residue is referred to as FCC slurry oil.
The FCC slurry oil had a C/H atomic ratio of
0.75 by elemental analysis and an aromatic carbon ratio
of 0.55 by NMR analysis.
Example 1
(First step)
100 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated for 2 hours at 420 C in a
nitrogen gas current of 1 liter/min to remo~e the 420 C
fraction. The residue was filtered at 150 C to remove
the portion which was not in a molten s-tate at 150 C,
and thereby to obtain 57 g of a lighter reforming pitch.
The reforming pitch had a xylene insoluble
content of 60%.
57 g of the pitch was mixed with 25 g of the
organosilicon polymer obtained in Reference Example 1 and
20 ml of xylene. The mixture was heated with stirring
and, after distilling ofE xylene, was subjected to a
reac-tion for 6 hours at 400 ~C to obtain 43 g of a reac-
tion product.
Infrared absorption spectrum analysis indicated
that in the reaction product there occurred the decrease
r -
- 63 -
of the Si-H bond (IR: 2100 cm 1) present in or~anosilicon
polymer and the new Eormation of Si-C (this C is a
carbon of benzene ring) bond (IR: 1135 cm~ Therefore,
i-t became clear that the reaction product contained a
5 structure in which part of the silicon atoms of organo-
silicon polymer bonded direc-tly with a polycyclic aroma-
tic ring.
The reac-tion product con-tained no xylene in~
soluble and had a weight-average molecular weight of 1450
and a melting point of 265 C O
(Second step)
400 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated for 1 hour at 450 ~C in a
nitrogen gas current of 1 liter/min to remove the 450 C
fraction. The residue was filtered at 200 C to remove
the portion which was not in a molten state at 200 C,
and thereby to obtain 180 g of a reforming pitch.
180 g of the reforming pitch was subjected to a
condensation reaction for 8 hours at 400 C in a nitrogen
20 current while removing the light fractions formed by the
reaction, to obtain 80.3 g of a heat-treated pitch. This
heat-treated pitch had a melting point of 310 C, a
xylene insoluble content of 97% and a quinoline insoluble
conten-t of 20~. The pitch was a meso phase pitch having
an optical anisotropy of 95 % when the polished surface
was observed by a polarizing microscope.
(Therd step)
40 g oE the reaction product obtained in the
first step and 80 g of the mesophase pitch obtained in
the second step were melt mixed for 1 hours at 350 C in
a nitrogen atomosphere to obtain a uniform silicon-
containing reaction product.
This silicon-containing reaction product had an
optical anisotropy of 51 %, a xylene insoluble content of
68 % and a melting point of 281 C. The reaction product,
when subjected to a hydrogenation reaction under mild
- 6~ -
conditions and suhsequently to the measuremen-t of weight-
average mo.Lecular weight by gel permeation chromatography
tGPC), had a ~w of 1250.
The above silicon-containing reac-t.ion product
was heated a-t 1000 ~C in air; -the resulting ash was
subjected to alkali ~usion and then to a hydrochloric
acid -treatment, and dissolved in wa-ter; the aqueous
solution was measured for silicon concen-tration using a
high frequency plasma ernission spectrochemical analysis
apparatus (ICP), which indicated that the silicon content
in the si]icon-containing reac-tion product was 5~2 ~.
Examples 2-8
Various silicon-containing reaction products
were obtained by varying the feeding ratio of -the organo-
silicon polymer and the reforming pitch and their copoly-
merization conditions in the first step of Example 1, -the
heat treatment conditions in the second step of Example
1, and the feeding ratio and the melt mixing (melt con~
densation) conditions in -the third step of Example 1.
The results are shown in Table 1 together with -the re-
sults of Example 1. In all the Examples, the obtained
silicon-containing reaction product had a silicon content
of 0.4-24.8 ~ and an optical anisotropy.
- 65 -
<IMG>
- 66 -
<IMG>
3~3
- 67 -
Comparative Example 1
(First step)
200 g of the ~'CC slurry oil obtalned in Refer-
ence Example 2 was heated for 2 hours at 420 C in a
nitrogen gas curren-t of 1 liter/min to remove the 420 C
fraction and thereby to obtain 114 g of a reforming
pitch. The pitch was dissolved in 500 ml of xylene of
130 C to remove 69 g of the xylene insoluble portion.
The resulting xylene soluble pitch portion (45 g) was
mixed with 45 g of the organosilicon polymer obtained in
Reference ~xxample 1, and the mixture was subjected to a
copolymeri~ation reaction for 6 hours at 400 C to obtain
32 g of a reaction product.
(Second step)
200 g of the xylene soluble pitch component was
subjected to a heat treatment for 6 hours at 400 C in an
inert atmosphere to obtain 41 g of a heat-teated pitch.
(Third step)
30 g of the reaction product obtained in -the
first step and 60 g of the heat-treated pitch obtained in
the second step were mixed with heating for 2.5 hours at
300 C
The product obtained above had a weight-average
molecular weight (~w) of 1750 and a silicon content of
10.5 %, bu-t had a low me]ting point of 198 C and a low
xylene insoluble content of 11 % and was optically iso-
tropic.
Comparative Example 2
100 g of the reforming pitch obtained in the
first step of Example 1 was mixed with 50 g of the organo-
silicon polymer obtained in Reference Example 1, and the
mixture was subjected to a reaction for 6 hours at 400 C
to obtain 79 g of a reaction product.
The reaction product had a melting point of
252 C and a silicon content of 15 ~ and contained no
xylene insoluble and no mesophase portion.
- 68 -
Example 9
Each of the silicaon-containing reaction pro-
ducts ob-tained in Examples 1 and 2 was used as a spinning
dope and subjected to melt spinning using a spinning
nozzle of 0.3 mm in diameterA The resu~ting precursor
fiber was cured at 300 C in an air current and then
subjected to pyrolyzing at 1300 ~C in an argon current to
obtain two carbonaceous inorganic fibers. The carbonace-
ous inorganic fiber producted from the Example 1 dope had
a diameter of 14 ~, a tensile strength of 190 kg/mm2 and
a -tensile modulus of elasticity of 18 t/mm2, and the
carbonaceous inorganic fiber produced from the Example 2
dope had a diameter of 17 ~, a tensile strength of 161
kg/mm2 and a tensile modulus of elasticity of 16 t/mm2.
Observation by a scanning type electron micro-
scope indicated that the both fibers had a sec-tional
structure similar to the radial structure preferably used
in pitch fibers and, in the two fibers, the mesophase
component which had been present in the respective dopes
was orientated to the fiber axis airection by the spin-
ning, curing and pyrolyzing procedures.
Comparative Example 3
Each of the reaction products obtained in
Comparative Examples 1 and 2 was subjected to spinning,
curing and pyrolyzing under the same conditions as in
Example 9 to obtain two pyrolyzed fibers. The Eiber
obtained from the Comparative Example 1 dope had a dia-
meter of 17 ~, a tensile strength of 105 kg/mm2 and a
tensile modulus of elasticity of 7.1 t/mm2~ and the fiber
obtained from the Comparative Example 2 dope had a dia-
meter of 16 ~, a tensile strength of 75 ~g/mm2 and a
tensile modulus of elasticity of 5.0 t/mm2.
The sections of these fibers contained no
structure showing orientation.
Example 10
(First step)
200 g of the FCC slurry oil obtained in ~efer-
- 69 -
ence Example 2 was heated for 0.5 hours at 450 C in a
nitrogen gas current of 2 liters/min to remove the 450 C
fraction. The residue was fi]~ered at 200 C to remove
-the portion which was not in a molten state at 200 C and
thereby to obtain 57 g of a reforming pi-tch.
This reforming pitch had a ~ylene insoluble
content of 25 %.
57 g of -the pitch was mixed with 25 g of -the
organosilicon polymer obtained in Rference Example 1 and
20 ml of xylene. ~he mixture was heated with stirring to
remove xylene and then subjected to a reaction Eor 6
hours a-t 400 C to obtain 51 g of a reaction productO
Infrared absorption spectrum analysis indicated
that in the reaction product there occurred the decrease
of the Si-H bond ~IR: 2100 cm~l) present in organosili,con
polymer and the new formation of Si-C (this C is a carbon
of benzene ring) bond (IR: 1135 cm-l). Therefore, it
became clear that the reaction produc-t contained a struc-
ture in which part of the silicon atoms of organosilicon
polymer bonded directly with a polycyclic aromatic ring.
The reaction product contained no xylene in-
soluble and had a weight-average molecular weight of
1400, a melting point of 265 C and a softening point of
310 C.
(Second step)
180 g of the reforming pitch was subjected to a
condensation reaction for 8 hours at 400 C in a nitrogen
current while removing the light fractions Eormed by the
reaction, to obtain 97.2 g of a heat-treated pitch. The
heat-treated pitch had a melting point of 263 C, a
softening point of 308 C, a xylene insoluble content of
77 % and a quinoline insoluble content of 31 ~. Obser-
vation by a polarizing microscope indicated that the
pitch was a mesophase pitch having an optical anisotropy
Of 75 ~,
(Third step)
70 _
~ .4 g of the reaction product obtained in the
first step and 90 g of the mesophase pitch obtained in
the second step were melt mixed Eor 1 hour at 380 C in a
nitrogen atomosphere to obtain a uniform silicon-contan-
ing reaction product.
This silicon-containing reaction product had an
optical anisotropy of 61 %, a xylene insoluble content of
70 ~, a melting point of 267 ~C and a softening point of
315 C.
The reaction product was subjected to hydro-
genation under mild conditions and then to gel permeation
chromatography (GPC) to measure the weight-average mole-
cular weight (~w) of the reaction product. The ~w was
900 .
The silicon-containing reaction product was
heated to 1000 ~C in air; the resulting ash was subjected
to slkali fusion and then to a hydrochloric acid treat-
ment, and dissolved in water; the aqueous solution was
measured for silicon concentration using a high frequency
plasma emission spectrochemical analysis apparatus (ICP),
which indicated that the silicon content in the silicon
containing reaction product was 0.91 ~. Examples 11-19
Various silicon-containing reaction products
were obtained by varying the feeding ratio of the organo-
silicon polymer and the lighter reforming pitch and theircopolymerization conditions in the first step of Example
10, the heat treatment conditions in the second step of
Example 10, and the feeding ratio and the melt mixing
(melt condensation) conditions in the third step of
Example 10. The results are shown in Table 2 together
with the results of Example 10. All of the silicon-
containing reaction products obtained in Examples 11-19
had an optical anisotropy.
- 71 -
<IMG>
- 72 -
<IMG>
~¢3~3~
- 73
Example 20
The silicon-containing reaction products ob-
tained in Examples 10, 11 and 19 were used as a spining
dope and subjected to melt spinning using a nozzle of
0.15 mm in diame-ter. Each oE the resul-ting precursor
fibers was cured at 300 C in an air corren-t and then
pyrolyzed at 1300 C in an argon current to obtain three
carbonaceous inorganic Eibers. ~`he fiber obtained from
the Example 10 dope had a diameter of 8 ~, a tensile
strength of 320 kg/mm2 and a -tensile modulus of elasti-
city of 26 t/mm2; the fiber obtained from the Example 11
dope had a diameter of 9 ~, a tensile strength of 260
kg/mm2 and a tensile modulus of elastici-ty of 24 t/mm2;
and the fiber obtained from -the Example 19 dope had a
1~ diameter of 3 ~, a tensile strength of 300 kg/mm2 and a
tensile modulus of elasticity of 22 t/mm2.
Observation by a scanning type electron micro-
scope indicated that all the fibers had a sectional
struture similar to the radial structure preferably used
in pitch fibers and, in these fibers, the mesophase
componnt which had been present in the respective dopes
was orientated to the fiber axis direction by the spin-
ning, curing and pyrolyzing procedures.
Example 21
(Firs-t step)
100 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated for 2 hours at 420 C in a
nitrogen gas current of 1 liter/min to remove the 420 C
fraction. The residue was filtered at 150 C to remove
the portion which was not in a moleten state at 150 C
and thereby to obtain 57 g of a reforming pitch.
The reforming pitch had a xylene insoluble
content of 60 ~.
57 g of the reforming pitch was mixed with 25
g of the organosilicon polymer obtained in Reference
Example 1 and 20 ml of xylene. The mixture was heated
-- 74 -
with s-tirring and, a~ter removing xylene, was subjected
to a reac-tion for 4 hours at 400 C to obtain 53 g of a
reaction procluct. InErared absorption spec-trum analysis
indicated tha-t in the reac-tion produc-t there occurred the
decrease of the Si-H bond (IR: 2100 cm-l) present in
organosilicon polymer and -the new formation of Si-C (this
C is a carbon of benzene ring)bond (IR: 1135 cm-1).
Therefore, it became clear -that the reaction product
contained a structure in which part of the silican atoms
Of organosilicon polymer bonded directly with a po]y-
cyclic aroma-tic ring.
The xeaction product contained no xylene in-
soluble and had a weight-average molecular weight oE 1150
and a melting point of 245 C.
(Second step)
400 g of the FCC slurry oil ob-talned in Refer-
ence Example 2 was heated to 420 C in a nitrogen gas
current to remove the 420 C fraction. The residue was
filtered at 150 C to remove the portion which was not in
a molten state at 150 C, and then subjected to a conden-
sation reaction for 9 hours at 400 C to ob-tain a heat-
treated pitch. The pitch had a melting point of 265 C,
a softening point of 305 C and a quinoline insoluble
content of 25 ~. Observation of the polished surface of
the pitch by a polarizing microscope indicated that the
pitch was a mesophase pitch showing anisotropy.
This mesophase pitch was hydrogeneted at a
hydrogen pressure of 100 kg/cm2 using a michel-cobalt
solid catalyst (carrier: zeolite), for l hour at 360 C.
The hydrogenation product contained no quinoline in-
soluble and, when the polished surface was observed by a
polarizing microscope, was an optically isotropic pitch.
This pitch was kept for 30 minuites at 400 C in a nitro-
gen current to effect heat stabilization and thereby to
obtain a heated-treated pitch. The resulting pitch
contained no quinoline insoluble, had a mel-ting point of
3~3
- 75 -
230 ~C and a so:Eteni.ng poing of 238 C, and was an iso-
tropic pitch. This heat-trea-~ed pitch was mede into a
fiber using a capi.llary of 0.5 mm in diameter; the fiber
was cured at 300 C in air and pyrolyzed at 1000 C in a
nitrogen current, and -the section of the resulting fiber
was observedl which indicated that the fiber had orien-
tation in the ~iber axis direction. Therefore~ the
hea-t-trea-ted p.itch was found to be poten-tially aniso-
tropic.
(Third step)
40 g oE the reaction product obtained in the
first step and 80 g of the heat-treated pitch obtained in
the second step were melt mixed for 1 hour a-t 350 C in a
nitrogen current to obtain a uniform si.licon-containing
reaction product.
This silicon-containing reaction product con-
-tained no quinoline insoluble and had a xylene insoluble
content of 32 %, an optical isotropy, a melting point of
241 C and a softening point of 262 C. The reaction
produc-t had a weight-averagge molecular weight (~w) of
980 as measured by gel permeation chromatography (GPC).
The silicon-containing reaction product was
heated to 1000 C in air; the resulting ash was subjected
to alkali fusion and then to a hydrochloric acid treat-
ment, and dissolved in water; the resulting aqueoussolution was measured for silicon concentration by a high
:Erequency plasma emission spectrochemical analyzer (ICP).
It indicated that the silicon content in the silicon-
containing reaction product was 5.4 ~.
Example 22
(First step3
A reaction poroduct was obtained in the same
manner as in the Eirst step of Example 21 except that the
ratio of the reforming pitch and the organosilicon poly-
mer was changed to 60 parts : 40 parts and the copolymeri-
zation temperature and time were chanyed to 420 C and 2
- 76 --
hoursl respectively. The reaction prod~lct had a melting
point of 238 C and a weight--average molecular weight (Mw~
of 1400 and contained no quinoline insoluble.
~Second step)
The same procedure as in the second step of
Example 21 was repeated except that the conditions for
obtaining a rnesophase were 420 C and 4 hours and the
hydrogenation was effected ror 2 hours a-t 95 C using
metallic lithium and ethylenediamine, to obtain a heat-
treated pitch. This heat-treated pitch had a melting
point of 225 C and a softening point of 231 C and was
confirmed by the same method as in Example 21 -to be
potentially anisotropic.
(Third step)
The same procedure as in the third step of
Example 21 was repeated except that -the feeding ratio of
the reaction product obtained in the above first step and
the heat-treated pitch obtained in the above second step
was 1:6 by weight and the mel;- mixing temperature wa 380
CF to obtain a silicon-containing reaction product.
This reaction product had a weight-avedrage molecular
weight (Mw) of 800, a silicon content of 3.2 %, a melting
point of 232 C and a softening point of 245 C.
Comparative Example 4
(First step)
This was effected in the same manner as in
Comparative Example 1.
(Second step)
200 g of the xylene-soluble pitch component
obtained in the first step was heat-treated for 2 hours
at 400 C in a nitrogen atomosphere to obtain 65 g of a
pitch which contained no quinoline insoluble and which
was optically isotropic. This pitch caused no orienta
tion when subjected to shear by the method of Example 21
and accordingly contained no potantially anisotropic
component.
(Third step)
3~ ~
'.0 g of the reaction product obtained in the
firs-t step and ~0 g of -the heat-treated pitch obtained in
the second step were mixed Eor 1 hour at 3A0 C~ The
resulting product had a weight-average molecular weigh-t
(Mw) of 1450 and a silicon--colltent of 9.8 % but a low
melting point of 185 CO
Example 23
The silicon-containing reaction products ob-
tained in Examples 21 and 22 were used as a spinning dope
and subjected to melt spinning using a nozzle of 0.3 mm
in diameter. The resulting precursor fibers were cured
at 300 C in an air current and pyrolyzed at 130Q C in
an argon current to obtain carbonized inorganic fibers.
The fiber obtained from the Example 21 dope had a dia-
meter of 10 ~, a tensile strength of 260 kg/mm2 and atensile modulus of elasticity of 20 t/mm2. The fiber
obtained from the Example 22 dope had a diameter of 9 u,
a tensile strength of 290 kg/mm2 and a tensile modulus of
elasticity of 24 t/mm~.
Observation by a scanning type electron micro-
scope indicated that the both fibers had a sectional
structure similar to the radial structure preEerably used
in pitch fibers and, in the two fibers, the mesophase
component which had been present in the respective dopes
was oriented to the fiber axis direction by the spinning,
curing and pyrolyzing procedures.
Comparative Example 5
The reaction product obtained in Comparative
Example 4 was subjected to spinning, curing and pyrolyz-
ing under -the same conditions as in Example 23 to obtain
a fiber. The fiber had a diameter of 17 ~, a tensile
strength of 95 kg/mm2 and a tensile modulus of elasticity
of 6.0 t/mm2. The section of the fiber contained no
portion of orientation struc-ture.
Example 24
(First step)
This was effected in the same manner as in the
3s ~
- 78 -
first step of Example lr
(Second step)
400 g of the FCC slurry oil obtained in Refer-
ence Example 2 and 300 g of .l,2,3,4-tetrahydroquinoline
were subjected to a hydrogenat;on treatmen-t for lQ
minutes at 450 C in an autoc]ave. Then, the te-txahydro-
quinoline was removed by distillation to obtain a hydro-
genated pitch.
The pitch was fed into a metallic container.
The container was immersed in a -tin bath under a reduced
pressure of 10 mmHg to trea-t the pitch for 10 minu-tes at
450 C to obtain 62 g of a pitch.
The pitch had a melting point of 230 Ct a
softening point of 238 C and a quinoline insoluble
content of 2 %.
(Third step)
40 g of the reaction product obtained in the
first step and 80 g of the pitch ootained in the second
step were melt mixed for 1 hour at 350 C in a nitogen
atomosphere to obtain a uniform silicon-containing
reaction product.
This silicon-containing reaction product had an
optical isotropy, a xylene insoluble content of 45 % and
a melting point of 251 C. The reaction product, when
hydrogenated under mil.d conditions and subjected to gel
permeation chromatography to measure a weight-average
molecular weight tMw), had a Mw of 1080.
The silicon-containing reaction product was
heated to 1000 C in air; the resulting ash was subjected
to alkali fusion and then to a hydrochloric acid treat-
ment, and dissolved in wa-ter; the resulting aqueous
solution was measured for silicon concentration by a high
frequency plasma emission spec-trochemical analyzer (ICP).
I-t indicated that the silicon content in the silicon-
containing reaction product was 5.8 % rExample 25
- 79 -
(First step)
- The same procedure as in Example 24 was repeat-
ed except that the ra-tio of the reforming pi-tch and the
organosilicon polymer was changed to 60 parts : 40 parts
and their copolymeriza-tion temperature and time were
changed to 420 C and 2 hours, respectively, to obtain a
reaction procuct. This reaction product had a melting
point of 238 C and a weight-average molecular weight
(~w) of 1400 and contained no ~uinoline insoluble.
~Second step)
The FCC slurry oil obtained in Reference Exam-
ple 2 was treated in an autoclave for 1 hour at 430 C in
a nitrogen atmosphere at an antogenic pressure of 95
kg/cm2 (hydrogen partial pressure was 21 kg/cm2~; then,
the 320 C or lower fraction was removed under a reduced
pressure of 10 mmHg; and the resulting pitch was heated
for 3 minutes at 450 C to obtain a heat-treated pitch
having a melting point of 251 C, a softening point of
260 C and a quinoline insoluble content of 5 %.
(Third step)
The same procedure as in Example 24 was repeat-
ed except that the feeding ratio of the raction product
obtained in the above first step and the heat-treated
pitch obtained in the above second step were 40 parts :
60 parts and the melt mixing tempera-ture and time were
380 C and 30 minutes, respectively, to obtain a silicon-
containing reaction product. The reaction product had an
optical isotropy, a xylene insoluble content of 39 %, a
weight-average molecular weight (~w) of 1210, a silicon
content of 8.2 ~ and a melting point of 258 C.
Example 26
The silicon-containing reaction products ob-
tained in Examples 23 and 24 were used as a spinning dope
and subjected to melt spinning using anozzle of 0.3 mm in
diameter. The resulting precursor fibers were cured at
300 C in an air current and pyrolyzed at 1300 C in an
- 80 -
argon current to obtain carbonized inorganjic fibers.
The fiber obtained from the Example 23 dope had a dia-
meter of 11 ~, a tensile strength of 288 kg/mm2 and a
tensile modulus of elasticity o-E 24 t~mm2. The fiber
obtained from -the Example 24 dope had a diameter of 9 ~,
a tensile strength of 261 kg/mm2 and a tensile modulus of
elasticity of 21 t/mm2
Observation by a scanning type electron micro-
scope indicated that the both fibers had a sectional
structure similar to the radial structure preferably used
in pitch fibers and, in the two fibers, the mesophase
component which had been present in the respective dopes
was orientated to the fiber axis direction by the spin-
ning, curing and pyrolyzing procedures.
Example 27
(First step)
170 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated to 420 C in a nitrogen gas
current to remove the 420 C fraction. The residue was
filtered at 150 C to remove the portion which was not in
a molten state at 150 C, to obtain 98 g of a reforming
pitch.
The xylene soluble portion was removed from the
reforming pitch to obtain a xylene insoluble component in
an amount of 60 %.
60 g of the xylene insoluble component was
mixed with 25 g of the organosilicon polymer obtained in
Reference Example 1 and 20 ml of xylene. The mixture was
heated with stirring and, after distilling off xylene,
subjected to a reaction for 4 hours at 400 C to obytain
58 g of a reaction product.
Infrared absorption spectrum analysis indicated
that in the reaction product there occurred the decrease
of the Si-~ bond (IR: 2100 cm~l) presen-t in organosilicon
polymer and the new forma-tion of Si-C (this C is a carbon
of benzene ring) bond (IR: 1135 cm~l~. Therefore, it
5~J
- 81 -
became clear that the reaction product contained a struc-
ture in which part of -the silicon atoms of organosilicon
polymer bonded directly with a polycyclic aromatic ring.
The above reaction product contained no xylene
insoluble and had a weight-average molecular weight of
1250 and a rnelting point of 2~8 C.
(Second step)
500 g oE the FCC slurry oil obtained in Refer-
ence Example 2 was heated to 450 C in a nitrogen gas
current to remove the 450 C fraction. ~he residue was
filtered at 20C C to remove -the portion which was not in
a molten state at 200 C and thereby to obtain 225 g of a
reforming pitch.
The xylene soluble portion was removed from the
reforming pitch to obtain 180 g of a xylene insoluble
portion.
180 g of the xylene insoluble portion was
subjected to a condensation reaction for 6 houxs at 400
C in a nitrogen current while removing the light frac-
tions formed by the reaction, to obtain 96 g of a heat~treated pitch. This heat-treated pitch had a melting
point of 262 C and a quinoline insoluble content of 7 ~.
The pitch was found by observing its polished surface by
a polarizing microscope, to be mesophase pitch having an
optical anisotropy of 96 ~.
(Third step)
40 g of the reaction product obtained in the
first step and 80 g of the mesophase pitch obtained in
the second step were rnelt mixed for 1 hour at 350 C in a
nitrogen atmosphere to obtain a uniform silicon-contain-
ing reaction poroduct.
The silicon-containing reaction product had an
optical anisotropy of 58 %, a xylene insoluble content of
71 % and a melting point of 250 C and, when subjected to
hydrogenation under mild conditions and then to measure-
ment of weight-average molecular weight (Mw) by gel
- 82 -
permeation chromatography (GPC), had a Mw of 1025.
The silicon-containing reaction product was
heated to 1000 C in air; ~he resulting ash was subjected
to al.]sali fusion and -then to a hydrochloric acid treat-
ment, and dissolved in water; the resul-ting aqueous
solution was measured Eor silicon concen-tration by a high
frequency plasam emission spectrochemical analyzer ~ICP).
It indicated -that the si.licon content in the silicon-
con-taining reaction product was ~.8 %.
Examp:Le 28
(First step)
The same procedure as in Example 27 was repeat-
ed except -that the xylene used as a solvent Eor washing
the reforming pitch was changed to benzene, -the ratio oE
the organosil.icon polymer and the benzene insoluble
portion was changed to 60 parts : 40 parts and the reac-
tion conditions were changed to 420 C and 2.5 hours, to
obtain a reaction product. This reaction product had a
melting point of 256 C and a weitht-average molecular
weight (Mw) of 1480.
(Second sted)
The same procedure as in Example 27 was repeat-
ed except that the xylene used as a solvent for washing
the reforming pitch was changed to toluene and the heat
treatment conditions were changed to 380 C and 12 hours,
to obtain a meso phase-containing pi-tch. This pitch had
a melting point of 248 C and a quinoline insoluble
con-tent of 5 % and was found by observing its polished
surface by a polarizing microscope, -to be a meso- phase
pitch having an optical anisotropy of 75 ~.
(Third step)
The same procedure as in Example 27 was repeat-
ed except that -the feeding ratio of the raction product
obtained in the above first step and the mesophase pitch
obtained in the above second step was 40 parts : 60 parts
and -the melt mixing conditions were 370 C and 30 minutes,
- 83 -
to ob-tain a silicon-containing raction product.
This react:ion product ha.d a melting point of
255 C, a xylene insoluble conten-t of 58 %, an optical
anisotropy of ~5 %, a weight-average molecular weight
(Mw) of 1210 and a silicon con-tent: oE 8.5 %~
Example 29
The silicon-containing reaction products obtain-
ed in Examples 27 and 28 were used as a spinning dope and
subjected to me]t spinning using a nozzle of 0~3 mm in
diameter. The resulting precursor fibers were cured at
300 C in an air current and pyrolyzed at 1300 C in an
argon current to obtain carbonized inorganic fibers~ The
fiber obtained Erom the F.xample 27 dope had a diameter of
12 ~ a tensile s-trength of 288 kg/mm and a tensile
modulus of elasticity of 26 -t/mm2. The fiber obtained
from the Example 28 dope had a diameter of 11 ~,
a tensile strength of 270 kg/1~m2 and a tensile modulus of
elasticity of 24 t/mm2.
Observation by a scanning type electron micro-
scope indicated that the bothe fibers had a sectinalstructure similar to the radial structure preferably used
in pitch fibers and, in the two finers, the mesophase
components which had been present in the respective dopes
was orientated to the fiber acis direction by the spin-
ning, curing and pyrolyzing procedures.Example 30
(1) The mesophase pitch having an optical aniso-
tropy of 95 %, obtained in the second step of Example 1
was allowed to stand at 350 C to separate and remove -the
light portion by means of specifi.c gravity differance and
thereby to obtain 80 g of the residue.
The reaction product obtained in the first step
of Example 1 was melted and allowed to stand at 300 C
to separate and remove the light portion by means of
specific gra-tivy difference and thereby to obtain 40 g of
the residue.
- 84 -
The above two residues (80 g and 40 g) were
mixed and allowed to stand for 1 hour at 350 c in a
nitrogen atomosphere to obtain a uniform silicon-contain-
ing reaction prsduct~ This reaction product had a melt-
ing point oE 290 C and a xylene insoluble content of 70
~. llereinafter, the reaction product is referred to as
the matrix polymer Io
(2) A two~dimensional plain weave fabric made fxom
a commercially available PAN-based carbon fiber having a
diameter of 7 ~m, a tensile strength of 300 kg/mm2 and a
tensile modulus of elasticity of 21 t/mm2 was cut into
discs each of 7 cm in diameter. The discs were impreg-
nated wi-th a xylene slurry containing 30 ~ of the matrix
polymer I and then dried to obtain prepreg sheets. In a
mold, these prepreg sheets were laminated in a total
sheet number of 30 with the fine powder of the matrix
polymer I being packed between each two neighboring
sheets and with the fiber direction of a sheet differing
from that of the lower sheet by 45 C, and hot pressed at
350 c at a pressure of 50 kg/cm2 to form a disc-like
molded material. This molded material was buried in a
carbon powder bed for shape retention and heated to 300
C at a rate of 5 C/h in a nitrogen current and then to
1300 C to carbonize the matrix. The resulting composite
material had a buld density of 1.60 g/cm3.
The composite material was immersed in a xylene
slurry containing 50 % of the polymer I; the system was
heated to 350 c under reduced pressure while distilling
off xylene; then, a pressure of 100 kg/cm2 was applied to
effect impregnation. Thereafter, the impregnated com-
posite material was heated to 300 C in air at a rate of
5 c/h for curing and carbonized at 1300 C. This impreg-
nation procedure was repeated three times to obtain a
material having a bulk density of 1.95 g/cm3. The com-
posite material had a flexural strength of 45 kg/mm2.Comparative Example 6
- 85 -
Using, as a matrix polymer, a petroleum-based
heat-treated pitch having a softening point of 150 C and
a carbon residue of 60 % f the procedure of Example 30 (2)
was repeated to obtain a carbon fiber-reinforced carbon
material. This material had a low bulk density of 1.67
g/cm3 and a low flexural strength of 15 kg/mm2.
Example 31
(1) 50 g of the organosilicon polymer obtained in
Reference Example 1 was mixed with 50 g of a reforming
pitch. The mixture was subjected to a reaction for 4
hours at 420 C to obtain a reaction product.
Separately, the reforming pitch was subjected
to a reaction for 4 hours at 430 C to obtain a mesophase
pitch.
The reaction product and the mesophase pitch
were mixed at a 50-50 weight ratio and melted tc obtain a
silicon-containing reaction product. Hereinafter, this
reaction product is referred to as the matrix polymer II.
(2) A three-dimensional fabric made from a Si-~-C-O
fiber [Tyranno (registered trade name) manufactured by
Ube Industries, Ltd.] was impregnated with a xylene
solution containing 50 % of the matrix polymer II obtain-
ed in (1) above, in an autoclave and, after removing
xylene by distillation, was pressurezed at 100 kg/cm2 at
400 C to obtain a molded material. This molded material
was cured at 280 C and pyrolyzed at 1300 C for carboni-
zation. The above procedure was repeated four times to
obtain a composite material having a bulk density of 1.88
g/cm3 and a flexural strength of 38 kg/mm2.
Example 32
A bundle of commercially available pitch-based
carbon fibers each having a diameter of 10 ~m, a tensile
strength of 300 kg/mm2 and a tensile modulus of elasticiy
of 50 t/mm2 and arranged in the same one direction and a
fine powder obtained by carbonizing the matrix polymer I
at 800 C were laminated by turns and hot pressed at 2000
3~3
- ~6 -
C a-t 500 kg/cm2. The resulting composite ma-terial had a
bulcl densi-ty of 2.n5 g/cm3 and a flexural streng-th of 58
kg/mm2.
Example 33
The composite materials of Examples 30, 31 and
32 and -the compjosite materia~ of Comparative Example 6
were each heated for 1 hour in an oven having an atmos-
pheric temperature o:E ~00 C and then measured Eor
flexural strength.
In the cornposite material of Comparative ~xam-
ple 6,oxidative degradation progressed to such an extent
that the strength measurement was impossible~ Meanwhile
in -the composite material of Example 30, the flexural
strength decreased by only 10 ~ and, in the composite
materials of Examples 31 and 32, no strength decrease was
seen.
Example 34
The powder of the matrix polymer I obtained in
Example 30 was heated to 800 C in a nitrogen current to
prepare a prefired material. This prefired material was
finely ground to obtain a prefired powder. This prefired
powder and an equal weight of the polymer I powder were
subjected to wet mixing to obtain a powder. The powder
was hot pressed at 350 C at 100 kg/cm2 to obtain a
disc-like molded material having a diameter of 7 cm.
This molded material was buried in a carbon powder bed
for shape retention and heated to 800 C in a nitrogen
current at a rate of 5 c/h and further to 1300 c for
carboni.zation. The resulting carbonaceous inorganic
material had a bulk density OL- 1. 50 g/cm3~
This carbonaceous inorganic material was im-
mersed in a xylene slurry containing 50 ~ of the polymer
I and heated to 350 C under reduced pressure while
distilling off xylene; a pressure of 100 kg/cm2 was
appliea for impregnation; the impregnated materi.al was
heated to 300 C in air at a rate of 5 C/h for curing
r~
- 87 -
and then carbonized at 1300 C. This impregnation and
carbonization procedure was repeated three rnore times to
obtain a material having a bulk densi-ty of 1.95 g/cm3.
The material had a flexural strength of 21 kg/mm2. This
carbonaceous inorganic material was pyrolyzed a-t 2500 c
in argon, whereby the bulk densi-ty and flexural. strength
improved to 1.9~ g/cm3 and 24 kg/mm2, respectively.
Also, the material had a flexural strength of 25 kg/mm2
at 1500 C in nitrogerl.
E~ample 35
A prefired powder was prepared from -the matrix
polymer I in the same manner as in Example 34. 70 % of
this prefied powder was added to 30n % of a powder of the
matrix polymer Il obtained in Example 31 (1)~ They were
molded and carbonized in the same manner as in Example 34
-to obtain a carbonaceous inorganic material having a bulk
density o:E 1.67 g/cm3.
In the same manner as in Example 34, this
material was immersed in a xylene slurry containing 50 ~
f the matrix polymer II and then carbonized; the impreg-
nation and carbonization procedure was repeated three
more times to obtain a carbonaceous inorganic ma-terial
having a bulk density of 2.01 g/cm3. The material had a
flexural strength of 23 kg/mm . ~hen this material was
kept for 24 hours at 600 C in air, there was no decrease
in weight or in strength.
Comparative Example 7
80 ~ of a synthetic graphite powder having a
bulk density of 0.15 g/crn3 (under no load) was mixed with
20 % oE the mesophase pitch obtained in the second step
of Example 1. The mixture was subjected to molding and
carbonization in the same manner as in Example 34 to
ob-tain a carbon material having a bulk density of 1.66
g/cm3.
The impregnation of the carbon material with
mesophase pitch and the subsequent carbonization of -the
.~d ~ ~ ~3 ~
- 8~ -
impregnated carbon material was repeated four times in
the same manner as in Example 34 to obtain a carbon
material having a bulk density of 1.9~ g/cm3.
The carbon material had a flexural s-trength of
5.0 kg/mm . When the ma-terial was kept for 24 hours a-t
600 C in air t the weight decreased by 20 ~ and the
material turned porous.
Comparative Example 8
The carbon material having a bul~ density of
1O66 g/cm3, obtained in Comparative Example 7 was covered
with a metallic silicon powder and heated to 1500 C to
give rise to melt impregna-tion J a reaction and sintering
and thereby to obtain a carbon-carbon silicide composite
material. The material had an improved flexural streng-th
f 8.2 kg/mm2. However, when the material was measured
for flrxural strength at 1500 c in nitrogen, the strength
decreased to 3.0 kg/mm~ because the unreacted siliconn
melted and consequently deformation occurred.
Example 36
(First step)
500 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated for 1 hour at 450 C in a
nitrogen gas current of 1 liter/min to distil off the 450
C fraction. The residue was fi]tered at 200 c to
remove the portion which was not in a molten state a-t 200
c and thereby to obtain 225 g of a reforming pitch.
This reforming pitch had a xylene insoluble
content of 75 % and an optical isotropy.
49 g of the pitch was mixed 21 g of the organo-
silicon polymer obtained in Reference Example 1 and 20 ml
of xylene. The mixture was heated with stirring and,
after distilling off xylene, was subjected ot a reaction
for 6 hours at 400 C to obtain 39 g of a precursor
reaction product.
Infrared absorption spectrum analysis indicated
that in the precursor reaction product there occurred the
- 89 -
decrease of -the Si-H bond (IR: 2100 cm 1) present in
organosilicon polyme.r and the new formation o:E Si-C (-this
C is a carbon oE benzene ring) bond (IR: 1135 cm l)o
Therefore, it became clear that the precursor reaction
product contained a structure in which part of the silicon
atoms of organosilicon polymer bonded directly with a
polycyclic aromatic ring.
(Second s-tep)
39 g oE the precursor reaction product was
mixed with 11 g of a xylene sol.ution containing 2.75 g
(25 %) of tetraoctoxy-titanium [Ti(OC8H17)~. AEter
distilling off xylene, the mi.xture was subjected to a
reacti.on for 2 hours a-t 340 C to obtain 38 g of a reac-
tion product.
The reaction product contained no ~ylene in-
soluble and had a weight-average molecular weight of 1650
and a melting point of 272 C.
(Third step)
400 g of a FCC slurry oil was heated to 450 c
in a nitrogen gas current to distil off the 450 C frac-
tion. The residue was filtered at 200 C to remove the
portion which was not in a molten state at 200 C, to
obtain 180 g lighter reforming pitch.
180 g of the pitch was subjected ot a conden-
sation reaction for 7 hours at 400 C in a nitrogencurrent while removing the ligh-t fractions formed by the
reaction, to obtain 85 g of a heat-treated pitch.
The heat-treated pitch had a melting point of
268 C, a xylene insoluble content of 92 % and a ~uino-
line insoluble content of 12 % and, when its polishedsurface was observed by a polarizing microscope, was a
mesophase pitch having an optical anisotropy of 89 %.
(Fourth step)
15 q oE the raction product obtaine in the
second step and 75 g of the mesophase pitch obtained in
-the third step were melt mixed for 1 hour at 310 c to
obtain a uni:E orm reaction product containing silicon and
_ 9~ _
ti-tanium.
This ti-tanium-containing reaction product had
an optical anisotropy of 66 901 a xylene insoluble of 74 %
and a melting point of 270 C and" when hydrogena-ted
under mild conditi.ons and measured :~or weigh-t-average
molecular weigh-t (MW) by gel permea-tion chromatography
(GPC), had a ~w of 880.
The ti-tanium-containing reac-tion product was
heated to 1200 c in air; the resulting ash was subjee-ted
to alkali fusion and then to a hydroehlorie aeid treat-
ment, and dissolved in water; -tne resul-ting aqueous
solution was measured or silicon and titanium eoneentra-
tions by a high frequeney plasma emission speetroehemieal
ana]y%er (ICP~. It indiea-ted that the silieon and -tita-
nium concentrations in teh titanium-eontaining reaetion
product were 3.1 % and 0.1 %, respeetively.
Examples 37-42
Various titanium-eontaining reaction produets
were obtained by varying the feeding ratio and reaetion
conditions of the piteh, the organosilieon polymer and
Ti(OC8H17)4 in the first and second steps of Example 36,
the heat treatment eonndi-tions in the third step of
Example 36 and the feeding ratio and melt mixing (melt
eondensation) eonditions in the fourth step oE Example
36. The results are shown in Table 3 together wi-th the
results of Example 36. In eaeh Example, the titanium-
containing reaction produet obtained eontained silieon
and titanium in amounts of 0.4-22.0 % and 0.01-3.5 %,
respeetively, and had an optieal anisotropy.
- 91 -
<IMG>
- 92 -
<IMG>
- 93 -
Comparative Example 9
~First step)
200 g oE the FCC oil slurry obtained in Refer-
ence Example 2 was heated a-t 420 ~C for 2 hours in a
nitrogen gas ~urrent of 1 liter/min to dis-til o-Ef -the 420
C fraction and thereby to obtain 11~ g oE a reforming
pitch~ The pitch was dissolved in 500 ml oE xylene of
130 C to remove 69 g of the xylene insrluble portion.
The resulting xylene soluble portion (45 g~ of the pitch
was mixed with 45 g of the organosilicon polymer obtained
in Reference Example l; and the mixture was subjected to
a copo:Lymerization reaction for 6 hours at 400 c to
obtain 32 g oE a precursor reaction product.
(Second step)
200 g of the xylene soluble pi-tch component
obtained in the first step was heat treated for 6 hours
at 400 C in an inert atmosphere to obtain 41 g of a
heat~treated pitch.
(Third step)
30 g of the copolymer obtained in -the first
step and 60 g of the heat-treated pitch obtained in the
second step were mixed for 2.5 hours at 300 C.
The resulting reaction product had a weight-
average molecular weight (Mw) of 1750 and a silicon
25 content of 10.5 % but had a low melting point of 19~ C,
a low xylene insoluble content of 11 % and an optical
isotropy.
Comparative Example 10
100 g of the mesophase pitch obtained in the
third step of Example 36 was mixed with 50 g of the
organosilicon polymer obtained in Example 1, and the
mixture was subjected to a reaction for 6 hours at 400 C
to obtain 79 g of a precursor reaction product. The
copolymer had a melting point of 252 C, a silicon con-
3~ tent of 15 % and a weight-average molecular weight ~Mw)
of 1400 and contained no xylene insoluble and no meso-
3 q~ ~ r~
- 9'1 -
phase portion.
Example 43
39 g of the precursor reac-tion product obtained
in -the first step of Example 36 was mixed with an ethanol-
xylene solution containing 5.4 g (1.5 %) of tetrakisacetyl-
acetonatozirconium. After distilling off the solvent,
the mixture was subjected to a polymerization reaction
for 1 hour at 250 C to obtain 39~5 g of a reaction
product.
20 g of this reaction product and 50 g of a
mesophase pitch prepared in the same manner as in Example
36 were melt mixed for 1 hour at 350 C to obtain 67 g of
a reaction product containing silicon and zirconium.
This zirconium-containing reaction product had
a melting point of 274 C, a xylene insoluble content of
69 % and a number-average molecular weight of 1050.
The silicon and zirconium contents in the
reaction product were 4.1 % and 0.8 %, respectively.
Example 44
Using 60 g of the mesophase pitch obtained in
Example 36 and 40 g of an organosilicon polymer, there
was obtained 57 g of a precursor reaction product in the
same manner as in Example 36.
40 g of this precursor reaction product was
mixed with an ethanol-xylene solution containing 7.2 g of
hafnium chloride. After distilling off ethanol and
xylene, the mixture was subjected to a polymerization
reaction for 1 hour at 250 C to obtain 43.5 g of a
reaction product.
20 g of this reaction product and 80 g of a
mesophase pitch were melt mixed for 1 hour at 350 C to
obtain 96 g of a hafnium-containing reaction product.
This hafnium-containing reaction product had a
melting point of 280 C, a xylene insoluble content of 76
% and a number-average molecular weight of 980.
The silicon and hafnium contents in the reac-
~ 3
- 95 -
tion product were 3.6 % and 1~9 ~" respectively.
Example 45
The metal-containing reaction products obtained
in EXamples 36, 3~, 39, 43 and 44 were used as a spinning
dope and subjected -to melt spinning using a nozzle of
0.15 mm in diameter. The resultlng precursor fibers
were cured at 300 c in an air current and pyrolyzed at
1300 c in an argon current to obt:ain carbonaceous in-
organic Eibers. The Eiber obtained from Example 36 dope
had a diameter of 9.5 ~, a tensile strength of 325 kg/mm2
and a tensile modulus of elasticity of 32 t/rnm2~ The
fiber obtained from Example 38 dope had a diameter of 9.0
~, a tensile strength of 318 kg/mm and a tensile modulus
of elasticity of 36 t/rnm2. The fiber obtained from
Example 39 dope had a diameter of 8.6 ~, a tensile streng-
th of 360 kg/mm and a tensile modulus of elasticity of
33 t/mm . The Eiber obtained from the Example 43 dope
had a diameter of 11.5 ~, a tensile strength of 340
kg/mm2 and a tensile modulus of elasticity of 34 t/mm2.
The fiber obtained from the Example 44 dope had a dia-
meter of 12.0 ~, a tensile strength of 328 kg/rnm2 and a
tensile modulus of elasticity of 38 t/mm2.
Observation of fiber section by a scanning type
electron microscope indicated that each fiber had a
coral-like radom structure, a random-radial structure
(the radial occupied a basic structure) and a spiral-like
onion structure and, in each fiber, the mesophase com-
ponent which had been present in its dope was orientated
to the film axis direction by the spinning, curing and
pyrolyzing procedures.
Comparative Example 11
The reaction products obtained in Reference
Examples 9 and 10 were subjected to spinning, curing and
pyrolyzing in the same conditions as in Example 45, to
obtain pyrolyzed fibers. The fiber obtained from the
Comparative Example 9 dope had a diameter of 11 ~, a
r
- 96 -
tensile strength oE 120 kg/mm2 and a tensile modulus of
elas-ticity oE 7~5 -t/mm2~ The Eiber obtained Erom the
Comparative Example 10 dope had a diameter oE 10.5 ~, a
tensile strength of 85 kg~mm~ and a ~ensile modulus of
elasticity of 5.7 t~mm2.
The sections oE these Eibers containecl no
orientat iOII S tructure.
Example 46
(First step)
700 g oE the FCC slurry oil obtained in Refer-
ence Example 2 was heated Eor 0.5 hours at 450 C in a
nitrogen gas current of 2 li-ters/min to distil off -the
450 C frac-tion. The residue was filtered at 200 C to
remove the portion which was not in a molten state at 200
1~ C, to obtain 200 g a reforming pitch.
This reforming pitch contained 25 6 oE a xylene
insoluble and was optically isotropic.
57 g of this pitch was mixed with 25 g of the
organosilicon polymer obtained in Reference Example 1 and
20 ml of xylene. The mixture was heated with stirring to
distil off xylene and subjected to a reac-tion for 4 hours
at 400 C to obtain 57.4 g of a precursor reaction product.
Infrared absorption spectrum analysis indicated
that in the precursor reaction product there occurred the
decrease of the Si-H bond (IR: 2100 cm l)present in the
organosilicon polymer and the new formation of Si-C (this
C is a carbon of benzene ring) bond (IR: 1135 cm 1).
Therefore, it became clear that the precursor reaction
product contained a structure in which part of the sili-
con atoms of organosilicon polymer bonded directly with apolycyclic aromatic ring.
(Second step)
57.4 g of the precursor reaction produc-t was
mixed with 15.5 g of a xylene solution containing 3.87 g
(25 6) of tetraoctoxytitanium [Ti(OC,3H17)~]. After
distilling off xylene, the mixture was subjected -to a
3~
- 97 -
reac-tion :Eor l hour at 340 C -~o obtain 56 g of a reac-
tion product.
This reac-tion product contained no xylene
insoluble and had a weight~averac;e molecular weight oE
5 1580r a melting point oE 258 ~C ancl a sof-tening point oE
292 C~
(Third step)
180 g of the ligh-ter reforming pitch obtained
in Reference Example 2 was suhjected to a condensation
reaction for 8 hours a-t A00 C while removing the light
fractions formed by the reaction, to obtain 97r2 g oF a
heat-treated pitch.
This heat~treated pitch had a melting point of
263 CI a softening point of 308 C~ a xylene insoluble
15 content of 77 % and a quinoline insoluble content of 31
and, by observing its polished surface by a polarizing
microscope, was found to be a mesophase pitch having an
optical anisotropy of 75
(Fourth step)
6~4 g of the reaction product obtained in the
second step and 90 g of the mesophase pitch obtained in
the third step wrer melt mixed for l hour at 380 C to
obtain a uniform titanium-containing reaction product.
This titanium-containing reaction product had
25 an optical anisotropy of 62 ~ ~ a xylene insoluble content
oE 68 QO~ a melting point of 264 C and a softening point
of 307 C and , when hydrogena-ted under mild conditions
and measured for weight-average molecular weight Mw by
gel permeation chromatography (GPC), had a Mw of 860~
The titanium-containing reaction product was
heated at 1200 c in air; the resulting ash was subjected
to alkali fusion and then to a hydrochloric acid treat-
ment, and dissolved in water; the aqueous solution was
measured for silicon and titanium concentrations using a
35 high frequency plasma emission spectrochemical analyzer
(ICP). It indicated that the silicon and titanium con-
~a~
9~
tents in -the titanium-containing reaction product were
0.91 ~ and 0.06 ~, respectively.
Examples 47-54
Va.rious -titanium-containing reac-ti.on produc-ts
were obtainecl by varying the :Eeeding ratio o.E the pitch,
the organosilicon polymer and Ti(OC~H17)4 and the.ir
reaction concli-tions in -the first and second steps of
Example 46~ the heat treatment conditions in the third
step oE Example 46 and the Eeeding ratio and -the melt
mixing (melt condensa-tion) conditions in the fourth s-tep
oE Example 46. The results are shown in Table 4 together
wi-th the results of Example 46. In each Example~ the
titanium-containing reaction product had an optical
anirotropy.
- 99 -
<IMG>
- 100 -
<IMG>
~ 101 --
Example 55
39 g of the precursor polymer obtained in
Example 46 was mixed wi-th an ethanol-xylene solution
containing 5.4 g (1.5 %) of tetrakisacetylacetonato
zirconium~ After disti]ling off -the solvent, the mixture
was subjected to a polymerization reaction for 1 hour at
250 c to obtain 39.5 g of a reaction product.
20 g of this reaction product and 50 g of a
mesophase pitch prepared in the same manner as in
Example 46 were melt mixed for 1 hour at 360 C -to obtain
67 g of a reaction product containing silicon and zir-
conium.
This zirconium-containing reaction product had
a melting point of 266 C, a xylene insoluble content of
54 ~ and a weight-average molecular weight of 1010.
The silicon and zirconium contents in the
reaction product were 4.1 % and 0.8 ~, respectevely.
Example 56
Using 60 g of the pitch obtained in Example 46
and 40 g of an organosilicon polymer, there was obtained
57 g of a precursor reaction product in the same manner
as in Example 46.
40 g of the precursor reaction product was
mixed with an ethanol-xylene solution contaning 7.2 g of
hafnium chloride. Af-ter distilling off xylene and
ethanol, the mixture was subjected to a polymerization
reaction for 1 hour at 250 C to obtain 43.5 g of a
reaction product.
20 g of this reaction product and 30 g of a
mesophase pitch were melt mixed for 1 hour at 350 C to
obtain 96 g of a hafnium-containing reaction product.
This hafnium-containing reaction product had a
melting point of 269 C, a xylene insoluble content of 60
% and a weight-average molecular weight of 930.
The silicon and hafnium contents in the reac-
tion product were 3.6 % and 1.9 %, respectively.
S~ ..a~
- 102 -
Examp~Le 57
The metal-containing reaction products obtained
in Examples ~6, 47, 54, 55 and 56 were used as a spinning
dope and subjected to melt spinning using a nozzle of
0.15 mm in diameter. The resulting precursor fibers were
cured at 300 ~C in an air current and pyrolyzed at 1300
C in an argon current to obtain carbonaceous inorganic
fibers. The fiber obtained from the Example 46 dope had
a diameter of 7.5 ~, a tensile strength of 358 kg/mm2 and
1~ a tensile modulus of elasticity of 32 -t/mrn2~ The fiber
obtained from the Example 47 dope had a diameter of 9.5
~, a tensile strength of 325 kg/rnm2 and a tensile modulus
oE elasticity of 32 t/rnm . The fiber obtained from the
Example 54 had a diameter of 8.5 ~, a tensile strength of
362 kg/mm2 and a tensile modulus of elasticity oE 34
t/mm2 The fiber obtained from the Example 55 dope had a
diameter of 11.0 ~, a tensile strength of 350 kg/mm2 and
a tensile modulus of elasticity of 34 t/mm2. The fiber
obtained from the Example 56 dope had diameter oE 12.0 ~,
a tensile strength of 340 kg/mm2 and a tensile modulus of
elasticity oE 38 t/mm2.
Observation of fiber section by a scanning type
electron microscope indicated that each Eiber had a
coral-like random structure, a random-radial structure
(th radial occupled a basic portion) and a spiral-like
onion structure and, in each fiber, the meso phase com-
ponent which had been present in its dope was orientated
to the fiber axis direction by spinning, infusibilization
and pyrolyzing procedures.
Example 58
(First step)
500 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated to 450 c in a nitrogen gas
current to distil off the 450 C fraction. The residue
was filtered at 200 ~C to remove the portion which was
not in a molten state at 200 ~C, to obtain 225 g of a
t~
- 103 -
reforming pitch.
This reforming pitch con-tained a xylene in-
soluble in an amount of 75 ~ and was ootically isotropic.
49 g oE the pitch was mixed with 21 g of the
organos;licon polymer obtained in ReEerence Example 1 and
20 ml oE xylene, and the mixture was heated with s-tirring
-to distil off xylene and then subjected to a reaction for
6 hours at 400 c to obtain 39 g of a precursor reaction
product.
Infrared absorption spectrum analysis indicated
that in the precursor reaction produc-t there occurred the
decrease of the Si-H bond (IR: 2100 cm 1) present in
organosilicon polymer and the new formation of Si-C (this
C is a carbon of benzene ring) bond (IR: 1135 cm l)
Therefore, it becsme clear that the precursor reaction
product contained a structure in which part of the silicon
atoms of organosilicon polymer bonded directly with a
polycyclic aromatic ring.
(Second step)
39 g of the precursor reaction product was
mixed with 11 g of a xylene solution containing 2.75 g
(25 ~) of tetraoctoxyti-tanium [Ti~oc8Hl7)4]. ~fter
distilling off xylene, the mixture was subjected to a
reaction for 2 hours at 340 C to obtain 38 g of a reac-
-tion product
This reaction product contained no xylene
insoluble and had a weigh-t-average molecular weight of
1650 and a melting point of 272 c.
(Thirs step)
400 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated -to 420 C in a nitrogen gas
current to distil off the 420 C fraction. The residue
was filtered at 150 c to remove the portion which was
not in a molten state at 150 C, and then subjected to a
polycondensa-tion reaction while removing -the light frac-
tions formed by the reaction, to obtain 75 g of a heat-
- 104 -
treated pitch. This hea-t-treated pi-tch had a mel-ting
point of 275 C, a softening point: of 305 C~ a xylene
insoluble content of 96 ~ and a quinoline insoluble
content of 25 ~5 ancl, by observing its polished surface by
a polarizing microscope, was found to be a mesophase
pitch having an optical anisotropy of 95 %.
I'his mesophase pitch was subjected to hydro-
genation for 1 hour at 360 c at a hydrocJen pressure of
100 kg~cm2 using a nichel-cobalt solid catalyst supported
by zeolite. The resulting hydrogenation produc-t contain-
ed no quinoline insoluble and, by oberving its polished
surface by a polarizing microscope, was found to be an
optically isotropic pitch~ This pi-tch was thermally
stabilized by keeping for 30 minutes at 400 c in a
nitrogen current, to obtain a heat-treated pitch. This
heat-trdeated pitch contained no quinoline insoluble and
had a melting point of 230 c, a softening point of 238
c and an optical isotropy. This pi-tch was made in-to a
precursor fiber using a capillary having a diameter of
0.5 mm; the precursor fiber was cured at 300 c in air
and pyrolyzed at 1000 C in a nitrogen current; the
resulting fiber had an orientation to the fiber axis
direction when its section was observed microscopically.
Therefore, the heat-treated pitch was potentially aniso-
tropic~(Fourth step)
40 g of the reaction product obtained in the
second step and 80 g of the heat-treated pitch obtained
in the third step were melt mixed for 1 hour at 350 C to
obtain a uniform titanium-containing reaction product.
This titanium-containing reactio product con-
tained no xylene insoluble and had an optical isotropy, a
melting point of 248 C and a softening point of 270 c.
The reaction product was measured for weight-average
molecular weight (Mw) by gel permeation chromatography
(GPC), which was lQ20.
-- 105 -
The -titanium-containing reaction product was
hea-ted to lOnO C in air, the resultirlg ash was subjected
to al]cali Eusion and -then to a hydrochloric acid -trea-tment,
and dissolved in water; the resulting aqueous solution
was measured Eor metal concentrations by a high frequency
plasma emission spectrochemical analyzer (ICP~. It
indicated -that the silicon and titanium contents in the
titanium-con-taining reaction products were 5.2 ~ and 0.2
%, respectively.
Exaple 59
(First step)
39 g of a precursor reaction product was obtain-
ed in the same manner as in the first step of Example 58.
(Second step)
39 g of the precursor reaction product was
mixed with an ethanol-xylene solution containing 5.4 g
~15 %) of tetrakisacetylacetonatozirconium. After distil-
ling off the solvent, the mixture was polymerized for 1
hour at 250 C to obtain 39.5 g of a reaction product.
(Third step)
A heat-treated pitch was obtained in the same
manner as in Example 58 except that the conditions for
converting to a meso phase were 420 C and 4 hours and
hydrogenation was effected for 2 hours at 95 C using
metallic lithium and ethylenediamine. This heat-treatedf
pitch had a melting poing of 225 C and a soEtening point
of 231 C,. and was found by the same method as in Example
58 to be potentially anisotropic.
(Fourth step)
20 g of the raction product obtained in -the
second step and 5a g of the heat-treated pitch obtained
in the third step were melt mixed for 1 hour at 350 c to
obtain 67 g of a reaction product containing silicon and
zirconium.
This zirconium-con-taining reaction product had
a melting point of 242 c, a softening point of 268 C,
a xylene insoluble content of 55 ~ and a weight-average
q~ r ~
106 -
molecular weight of 960.
The silicon and zirconium contents in the
reaction produc-t were ~.1 % and 0.8 ~, respectively.
Example 60
(First step~
Using 6n y of the pitch obtained in the Eirst
step of Example 58 and 40 g of an organosilicon polymer,
there was obtained 57 g of a precursor reaction product
in the same manner as in E~ample 58.
(Second step)
40 g of the precursor reaction product was
m,ixed with an ethanol-xylene solution containing 7.2 g oE
haEnium chloride. After distilling off ~ylene~ the
mixture was polymerized for 1 hour at 250 C -to obtain
43.5 g of a reaction product.
(Third step)
A heat-treated pitch was obtained in the same
manner as in Example 58 except that the conditions for
converting to a mesophase were 430 c and 1 hour and
hydrogenation was effected for 1 hour at 420 C at a
hydrogen pressure of 80 kg/cm2 using no catalyst. This
heat-treated pitch had a melting point of 233 C and a
softening point of 241 C and was conEermed by the same
method as in Example 58 to be potentialy aniso-tropicO
(Fourth step)
20 g of -the reaction product obtained in the
second step and 50 g of the heat-treated pitch obtained
in the third step were melt mixed for 1 hour at 350 C to
obtain 95 g of a reaction product containing silicon and
hafnium.
This hafnium-containing reaction product had a
melting point of 248 c, a softening point of 271 C, a
xylene insoluble content of 63 ~ and a weight-average
molecular weight of 890.
The silicon and hafnium conten-ts in the reaction
product were 3.6 % and 1.9 %, respectively.
-- 107 -
Example 6:L
l'he metal--containing reaction products obtained
in Examples 58, 59 and 69 were used as a spinning dope
and subjected to melt spinning using a nozzle of 0.15 mm
in diameter. The resulting precursor fibers were cured
at 300 C in an air current and pyrolyzed at 1300 c in
an argon current to obtaln carbonaceous inorganic fibers.
These Eibers had diameters, tensile strenqths and tensile
moduli of elasticity oE 9~0 ~, 360 kg/mm2 and 30 -t/mm2 in
the case of the fiber obtained from the Example 58 dope,
10.9 ~, 365 kg/mm2 and 33 t/mm2 in the case of the fiber
obtained from Example 59 dope and 11.2 ~, 351 kg/mm2 and
32 t/mm2 in the case of the fiber obtained from the
Exxample 60 dope.
Observation of fiber section by a scanning type
electron microscope indicated that each fiber had a
coral-like random structure, a random-radial structure
(the radial occupied a basic structure) and a spiral-like
onion struc-ture and, in each fiber, the meso phase com-
ponent which had been present in its dope was orientated
to the fiber axis direction by the spinning, curing and
pyrolyzing procedures.
Example 62
(First and second steps)
These two steps were effected in the same
manner as in the first and second steps of Example 36.
(Third step)
400 g of the FCC slurry oil obtained in Refer-
ence Example 2 and 300 g of 1, 2, 3, 4--tetrahydroquinoline
30 were sub~ected to hydrogenation for 10 minutes at 450 c
in an autoclave. Then, -the tetrahydroquinoline was
distilled off to obtain a hydrogenated pitch.
The pitch was fed in-to a metallic container.
The container was immersed in a tin ba-th under a reduced
pressure of 10 mmHg, and the pitch in the container was
heat treated for 10 minutes at 450 C to ob-tain 62 g of a
~C~
- 108 -
hea-t-treated pitch.
The heat-treated pitch had a melting point of
230 ~c, a softening point of 238 ~C and a quinoline
insoluble con-tent of 2~.
(Fourth step)
~ 0 g of the reaction product obtained in the
second step and 80 g of the heat-treated pi-tch obtained
in the third step were melt mixed for 1 hour a-t 350 C in
a nitrogen atomosphere to obtain a unEorm titanium-
containing reaction product.
This titanium-containing reaction product had
an optical isotropy, a xylene insoluble content of 50 ~,
a melting point of 254 C and a softening point of 271 C
and, when hydrogenated under mild conditions and measured
for weight-average molecular weight (~w) by gel permea-
tion chromatography ~GPC), had a ~w of 1100.
The titanium-containing reaction product was
heated to 1000 C in air; the resulting ash was subjected
to alkali fusion and then to a hydrochloric acid treat-
ment, and dissolved in water; the resulting aqueoussolution was measured for metal concentrations using a
high frequency plasma emission spectrochemical analyzer
(ICP). It indicated that the silicon and titanium con-
tents in the titanium~containing reaction product were
5-8 % and 0.2 ~, respectively.
Example 63
(First step)
A precursor reactio product was obtained in the
same manner as in the first step of Example 62.
(Second step)
39 g of the precursor reaction product was
mixed with an ethanol-xylene solution containing 5.4 g
(1.5 ~) of -tetrakisacetylacetonatozirconium. After
distilling off the solvent, the mixture was polymerized
for 1 hour at 250 C to ob~ain 39.5 g O-r a reaction
product.
(Third step)
- 109 -
The FCC slurry oil obtained in Reference Example
2 was hydrogenated in an autoclave for 1 hour at 350 C
at a hydrogen pressure of 80 ~g/cm2 using a nickel-cobalt
sol:id catalyst suppor-ted by zeolite. The resul-ting oil
was put under a reduced pressure of 15 mmlIg to distil off
the 320 C or lower fraction. The resu]ting pitch was
heated Eor 10 minutes at 440 c under a reduced pressure
of 2 mmFlg to obtain a heat-treated p:i-tch having a melting
point oE 248 C~ a softening point of 255 C and a ~uino-
line insoluble content of 1 ~.
(Fourth step)
20 g of the reaction product obtained in thesecond step and 50 g of the heat-treated pitch obtained
in the third step were melt mixed for 1 hour at 350 C to
obtain 67 g of a reaction product containing silicon and
zirconium.
This zirconium-contining reaction product had a
melting point of 254 C, a softening point of 273 C, a
xylene insoluble content of 61 % and a weight-average
molecular weight (~w) -to 1010.
The silicon and zirconium contents in the
reaction product were 4.0 % and 0.8 ~, respectively.
Example 64
(First step)
Using 60 g of the pitch obtained in Example 62
and 40 g of an organosilicon polymer, there was obtained
57 % of a precursor reaction product in the same manner
as in Example 62.
(Second step)
40 g of the precursor reaction product was
mixed with an ethanol-xylene solution containing 7.2 g of
hafnium chloride. After distilling off the solvent, the
mix-ture was polymerized for 1 hour at 250 C to obtain
43.5 g of a reaction product.
(Third step)
The FCC slurry oil obtained in Reference Exam-
- 110 -
ple 2 was treated in an autoclave Eor 1 hour at 430 C in
a ni-trogen atmosphere at an autogenic pressure oE 95
]ig/cm2 (hydrogen par-tial pressure was 21 kg/cm2~. Then,
the 320 C or lower fraction was removed under a reduced
pressure of 10 INm Hg. The resulting pitch was heated for
3 minutes at 450 C under a reduced pressure of 10 mmHg
to obtain a heat-trea-ted pitch having a melting point of
251 c, a softening point of 260 C and a quinGline
insoluble content of 260 C~
(Fouxth step)
20 g of the reaction product obtained in the
second step and 30 g oE the heat-treated pitch obtained
in the third step were melt mixed for 1 hour at 350 C to
obtain 96 g of a reaction product containing silicon and
hafnium~
This hafnium-containing reaction product had a
melting point of 253 C, a xylene insoluble content of 71
and a weight-average molecular weight of 870.
The silicon and hafnium contents in the reaction
product were 3.6 % and 1.9 %, respectively.
Comparative Example 12
(First step)
200 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated to 420 C in a nitrogen gas
current to distil off the 420 C fraction to obtain 114 g
of a reforming pitch. The pitch was dissolved in 500ml
or xylene of 130 C. The xylene insoluble portion ~69 g)
was removed and the resulting xylene soluble portion (45
g) of the pitch was mixed with 45 g of the organosilicon
polymer obtained in Reference Example 1. The mixture was
subjected to a copolymerization reaction for 6 hours at
400 c to obtain 32 g of a precursor polymer.
(Second step)
200 g of the xylene soluble pitch component
ob-tained in the first step was heat treated for 2 hours
at 400 ~C in a nitrogen gas current to obtain 65 g of
heat-treated pitch which contained no quinoline insoluble
and which had an optical isotropy.
(Third step~
30 g oE the precursor polymer obtained in the
Eirst step and 60 g oE the heat-trea-ted pi-tch obtained in
the second step were miced for 1 hour at 340 C. The
resulting product had a weigh-t-average molecular weight
~w) of 1450 and a silicon con-tent of 9.8 ~ but had a
mel-ting point oE 185 C~
Comparative Example 13
100 g of the reforming pitch obtained in Exam-
pie 62 and 50 g of the organosilicon polymer obtained in
Reference Example 1 were reacted for 6 hours at 400 C to
obtain 79 g of a precursor polymer.
The precursor polymer had a melting point oE
252 C, a silicon content of 15 ~ and a weight-average
molecular weight (~w) of 1400.
Examp~e 65
The metal-containing reaction products obtained
in Examples 62, 63 and 64 were used as a spinning dope
and subjected to melt spinning using a nozzle of 0.15 mm
in diameter. The resulting precursor fibers were cured
at 1300 C in an air current and pyrolyzed at 300 C in
an argon current to obtain carbonaceous inorganic fibers.
These fibers had diameters, -tensile strengths and tensile
moduli of elasticity of 9.5 ~, 345 kg~mm2 and 32 t/mm2 in
the case of the Eiber obtained from the Example 62 dope,
12.0 ~, 350 kg/mm2 and 34 t/mm2 in the case of the fiber
obtained from the Example 63 dope and 12.5 ~, 330 kg/mm2
and 33 t/mm2 in the case oE the fiber obtained from the
Example 64 dope.
Observation of fiber section by a scanning type
electron microscope indicated that each fiber had a
coral-like random structure, a random-radial structure
(the radial occupied a basic portion) and a spiral-like
onion structure and, in each fiber, the meso-phase com-
- 112 --
ponent which had been present in its dope was orientated
to the -tiber axis direction by the spinning, curing and
pyroly 2 ing procedures~
Comparative Example 14
rrhe polymers obtained in Compara-tive Examples
12 and :L3 were subjected to spinning, curing and pyrolyz-
ing under the same conditions as in Example 65, to ob-tain
pyrolyzed Eibers~ These Eibers had diameters, tensile
strength and tensile moduli of elasticity oE 17 ~, 95
kg/mm2 and 6.0 t/mm2 in the case of the fiber obtained
from -the Comparative Example 12 dope and 16 ~, 75 kg/rnm2
and 5.0 t/mm2 in the case of the fiber obtained from -the
Comprative Example 13 dope. The sec-tion of each fiber
contained no orientation structure.
Example 66
(First step)
500 g of the FCC slurry oil obtained in Refer-
ence Example 2 was heated to 450 ~C in a nitrogen gas
current to distil off the 450 c fraction. The residue
was filtered at 200 c to remove -the portion which was
not in a molten state at 200 C, to obtain 225 g of a
iighter reforming pitch.
From this reforming pitch was removed the
xylene soluble to obtain 180 g of an organic solvent
in5Oluble (1).
49 g of the organic solvent insoluble (1) was
mixed with 21 g of the organosilicoan polymer obtained in
Reference Example 1 and 20 ml of xylene. The mixture was
heated with stirring to distil off xylene and then subject-
ed to a reaction for 4 hours at 400 C to obtain 48 g ofa predursor reaction product.
Infrared absorption spectrum analysis indicated
that in the precursor reaction product -there occurred the
decrease of the Si-H bond (IR: 2100 cm~l) presen-t in
organosilicon polymer and the new formation of Si-C (this
C is a carbon of benzene ring) bond (IR 1135 cm~l).
- 113 -
Therefore, it became clear that the precursor reaction
product contained a structure in which par-t oE the silicon
atoms oE organosilicon polymer bonded dîrec-tly with a
polycyclic aromatic ring.
tSecond step~
50 g oE the precursor reaction product was
mixed with a 11 g of xylene solution containing 4.0 g (25
%) of tetraoctoxytitanium [Ti(OC8~17)~l]. After dis-
tilling off xylene, the mix-ture was subjeeted -to a reae~
tion for 2 hours at 340 C to obtain 49 g of a reaction
product.
This reaction product contained no xylene
insoluble and had a weight-average molecular weight of
1710 and a melting point of 275 C.
(Third step)
180 g of the organic solvent insoluble ~1)
obtained in the first step was subjected to a polyeonden-
sation reaetion for 6 hours at 400 c in a nitrogen
eurrent while distilling off the light fraetions formed
by the reaction, to obtain 96 g of a heat-treated pitch.
The heat-treated pitch had a melting point of 262 C and
a quinoline insoluble eontent of 7 % and, when its polish-
ed surface was observed by a polarizing mieroseope, was a
mesophase piteh having an optical anisotropy of 96 %~
(Fourth step)
40 g of the reaction product obtained in the
second step and 80 g of the mesophase pitch obtained in
the third step were melt mixed for 1 hour at 350 C in a
nitrogen atmosphere to obtain a uniform -titanium-contain-
ing reaetion produet.
This titanium-eontaining reaetion product had
an optieal anisotropy of 61 %, a xylene insoluble eon-tent
of 75 %, a melting point of 263 C and a softening point
of 272 C and, when hydrogenated under mild conditions
and measured for weight-average molecular weight (~w) by
gel permeation chromatography (GOC), had a ~w of 1045.
- 114 -
This titanium-containing reaction product was
heated to 1000 C in air, the resul-ting ash was subjected
-to alkali fusion and then to a hydrochloric acld trea-t-
ment , and dissolved in water; the resulting- aqueous
solution was measured for metal concentra-tions using a
high frequency plasma emission spec-tro-chemical analyzer
(ICP)~ It indicated that the silicon ancl titanium con-
tents in the titanium-containing reaction product were
4.8 % and 0.18, respectively.
Example 67
(First step)
A precursor reaction product was obtained in
the same manner as in the first step of Example 66.
(Second step)
39 g of the precursor reaction product was
mixed with an e-thanol-xylene solution containing 5.4 g
(1.5 %f) of ~etrakisacetylacetonatozirconium. After
distilling off the solvent, the mixture was polymerized
for 1 hour at 250 ~C to obtain 39.5 g a reaction product.
(Third step)
A mesophase pitch was obtained in the same
manner as in Example 66 except that the solvent used -Eor
washing the reforming pitch was toluene and the heat
treatment conditions were 380 C and 18 hours, The
mesophase pitch had a melting point of 248 C and a
quinoline insoluble of 5 % and, when its polished surface
was observed by a polarizing microscope, had an optical
anisotropy of 75 %.
(Four-th step)
20 g of the reac-tion product obtained in the
second step and 50 g of the meso phase pitch obtained in
the third step were melt mixed for 1 hour at 350 CC to
obtain 67 g of a reac-tion product containing silicon and
zirconium.
This zirconium-containing reaction product had
'ie~,
- 115 -
a melting polnt of 258 ~C, a softening point of 270 C, a
xylene insoluble content oE 72 % and a weight-average
molecular weight ~w) of 960.
The silicon and zirconium contents in the
reaction product were 4.1 % and 0.8, respectively.
Example 68
(First step~
Using 60 g of the organic solvent insoluble (1)
obtained in Example 66 and 40 g of an organosilicon
polymer, there was obtained 57 g of a precursor reaction
product in the same manner as in Example 66.
(Second step)
40 g of -the precursor reaction product was
mixed with an ethanol-xylene solution containing 7.2 g of
hafnium chloride. A-f-ter distilling off xylene, the
mixture was polymerized for 1 hour at 250 C to obtain
43.5 g of a reaction product.
(Third step)
A mesophase pitch was obtained in the same
manner as in Example 66 except that the solvent used for
washing the reforming pitch was benzene and the heat
treatment conditions were 420 C and 4 hours. This
mesophase pitch had a melting point of 256 C and a
quinoline insoluble content of 7 % and, when i-ts polished
surface was observed by a polarizing microscope, had an
optical anisotropy of 80 %.
(Fourth step)
20 g of the reaction product obtained in the
second step and 80 g of the mesophase pitch obtained in
the third step were melt mixed for 1 hour at 350 C to
obtain 97 g of a reaction product containing silicon and
hafnium. This hafnium-containing reaction product had a
melting point of 260 C, a xylene insoluble content of 79
~ and a weight-average molecular weight of 920.
The silicon and hafnium contents in the react-
- 116 -
ion product were 3.6 % and 1.9 %, respectively.
Example 69
The metal-con-taining reaction products obtained
in Examples 66D67 and 68 were used as a spinning dope and
subjected to melt spinning using a nozzle of 0.15 r.lm in
diameter. The resulting precursor fibers were cured at
300 C in an air current and pyrolyzed at 1300 ~C in an
argon current to obtain carbonaceous inorganic fibers.
These fibers had diameters, tensile streng-ths and tensile
moduli of elasticity of 9,5 ~, 340 kg/mm2 and 32 t/mm2 in
the case of the fiber obtained from the Example 66 dope,
11.1 ~, 348 kg/mm2 and 34 t/m2 in the case of the fiber
obtained from the Example 67 dope and 11.5 ~, 332 kg/mm2
and 32 t/mm2 in the case of the fiber obtained from the
~xample 68 dope.
observation of fiber section by a scanning type
electron microscope indicated that each fiber had a
coral-like random structure, a random-radial structue
(the radial occupied a basic portion) and a spiral-like
onion structure and, in each fiber, the mesophase com-
ponent which had been present in its dope was orientated
to the fiber axis direction by the spinning, curing and
pyrolyzing procedures.
Example 70
(1) 35 g of the raction produet ob-tained in the
second step of Example 36 and 70 g of the mesophase
pitch obtained in the third step of Example 36 were melt
mixed Eor 1 hour at 350 C in a nitrogen atmosphere to
obtain a uniform reaetion product eontaining silicon and
titanium.
This reaction product had a melting point of
272 C and a xylene insoluble content of 59 %. Herein-
after the reaction product is referred to as the matrix
polymer III.
(2) A two-dimensional plain weave Eabric made from
a commercially available P~N-based carbon fiber having a
- 117 -
diameter oF 7 ~m; a tensile strength of 300 kg/mm and a
tensile modulus of elasticity oE 21 t/mm was cut into
discs of 7 cm in diameter. The discs were impregnated
with a xylene slurry containing 30 ~ of -the matrix poly-
mer III and -then dried to ob-tain prepreg sheets. In a
die, these prepreg sheets were laminated in a ~otal sheet
number oE 30 with the Eine powder of the matrix polymer
III being packed between each two neighboring sheets and
with the Eiber direction of a sheet differing from that
Of -the lower sheet by 45 , and hot pressed at 350 C a-t
a pressure of 50 kg/cm to form a disc--like molded
material. This molded material was buried in a carbon
powder bed shape reten-tion and heated to 800 C at a rate
of 5 C/h in a nitrogen current and then to 1300 C to
carbonize the matrix. The resulting composite ma-terial
had a bulk density of 1.67 g~cm .
The composite material was immersed in a xylene
slurry containing 50 % of the matrix polymer III; the
system was heated to 350 C under reduced pressure while
dis-tilling off xylene; then, a pressure of 100 kg/cm was
spplied to effect impregnation. Thereafter, the impreg-
nated composite material was heated to 300 C in air at a
rate of 5 C/h for infusibilization and carbonized at
1300 C. This impregnation procedure was repeated three
times to obtain a material having a bulk density of 2.05
g/cm . The composite material had a flexural strength of
55 kg/mm .
Comparative Example 15
Using, as a matrix polymer, a petroleoum-based
heat-treated pitch having a softening point of 150 C and
a carbon residue of 60 ~, there was obtained a carbon
fiber-reinforced carbon material, in the same manner as
in Rxample 70. The material had a bulk density of 1.71
g/cm and a flexural strength of 19 kg/mm .
Example 71
(1) 39 g of the precursor reaction product obtained
5~
- ll8 -
in the first step of Example 36 was mixed with an ethanol-
xylene solution containing 5.4 g (1.5 ~) of tetrakisacetyl-
acetonato~irconium. AEter distilling off xylene and
ethanol, the mixture was polymerized for 1 hour a-t 250 C
-to obtain 39.5 g oE a reaction produc-t.
20 g of the reaction product and 50 g of a meso
phase pitch prepaxed in the same manner as in the fiest
step of Example 36 were finely ground and melt-mixed and
at 350 C to ob-tain a zirconium-containing reaction
product
This reaction product is hereinafter reEerred
to as -the matrix polymer IV.
(2) A bundle oE commercially available pitch-based
carbon fibers each having a diameter of 10 ~m, a tensile
strength of 300 kg/mm and a tensile modulus of elasti-
city of 50 t/mm and arranged in the same one direction
and a fine powder obtained by carboni~ing the ma-trix
polymer IV at 800 C were laminated by turns and hot
pressed at 2000 c a-t 500 kg/cm . The resulting com-
posite material had a bulk density of 2.05 and a flexuralstrength of 61 kg/mm .
Example 72
(1~ 57 g of a precursor reaction product was obtain-
ed in the same manner as in the first step of Example 36
except that the amounts of the reforming pitch and the
organosilicon polymer used were changed to 50 g and 50 g,
respectively.
40 g of the precursor reaction product was
mixed with an ethanol-xylene solution containing 7.2 g
(1.5 %) of hafnium chloride. ~fter distilling oE-f xylene
and ethanol, the mixture was polymerized for 1 hour at
250 ~C to obtain 43.5 g of a reaction product.
60 g of the reaction product and 40 g of a
mesophase pitch were melt mixed at 320 C to obtain a
hafnium-containing reaction product. This product is
hereinaf-ter referred to as the matrix polymer V.
- 119 -
(2) A three-dimensional fabric made from a Si-M-C-o
.Eiber [Tyranno (regis-tered trade name~ manufactured by
Ube Illdustries, Ltd.] was mpregnated with a xylene
solution containing 30 % of -the matrix polymer ~, in an
S autocl.ave and, after distilling off xylene, was pressuriz-
ed at 100 kg/cm at 400 C to obtain a molded material.
This rnolded material was cured at 280 ~C and pyrolyzed at
1300 C for carboniza-tion. The above procedure was
repeated Eour times to obtain a composite material having
a bulk density of 1.91 g/cm and a flexural strength of
42 kg~mm .
Example 73
The composite materials of Examples 70-72 and
-the composite material of Comparative Example 15 were
heated for 1 hour in an air oven of 500 C and then
measured for flexural strength~
In the composite material of Comparative Example
15, oxidative deterioration progressed to such as extent
that the measurement of flexural strength was i.mpossible.
In the composite material of Example 70, the flexural
strength decreased by only 7 ~. In the composi-te
materials of Examples 71 and 72, there was no decrease in
flexural strength.
Example 74
The powder of the matrix polymer III obtained
in Example 70 (1) was heated to 800 C in a nitrogen
current to prepare a prefired material. This material
was finely ground to obtain a prefired material powder.
The prefired material powder was set mixed with an equal
weight of the powder of the matrix polymer III. The
resulting powder was hot pressed at 100 kg/cm at 350 C
to obtain a disc-like molded material of 7 cm in dia-
meter. This molded material was buried in a carbon powder
bed for shape retention and heated to 800 C at a rate of
5 C/h in a nitrogen current and further to 1300 C for
carboni2ation. The resulting carbonaceous inorganic
- 120 -
ma-terial had a bulk density of 1.52 g/cm3.
The carbonaceous inorganic material was immers-
ed in a xylene slurry containing 50 ~ of the matrix
polymer ITI; the system was heated to 350 C under re~
duced pressure while distilling off xylene; then, a
pressure of 100 kg/cm2 was applied to eEfect impreg-
nation. ThereaEter, the impregnated composite materia]
was heated to 300 C in air at a rate of 5 C/h Eor
curing and carbonizecl a-t 1300 C. This impregnation and
carboniæation procedure was repeated three more times to
obtain a material having a bulk density of 1.96 g/cm3.
The material had a Elexural strength of 23 kg/mm . When
the carbonaceous inorganic material was fired at 2500 C
in argon, the bulk density and the flexural strength
improved to 1.99 g/cm3 and 28 kg/mm2, respectively. The
flexural strength at 1500 C in nitrogen was 29 kg/mm2.
Example 75
The matrix polymer IV obtained in Example 71
(1) was subjected to the same procedure as in Example 74
tG obtain a prefired powder. 70 ~ of this prefired
powder was mixed with 30 % of the powder of the matrix
polymer V obtained in Example 75 (1), and the mixture was
molded and carbonized in the same manner as in Example 74
to obtain a carbonaceous inorganic material having a bulk
density of 1.72 g/cm3.
In the same manner as in Example 74, this
material was impregnated with a xylene slurry containing
50 % of the matrix polymer IV; the impregnated material
was carbonized; this impregnation and carbonization
procedure was repeated three more times to obtain a
carbonaceous inorganic material having abulk density of
2.04 g/cm3. This material had a flexural strength of 28
kg/mm . When the material was kept for 24 hours at 600
C in air, there was no reduction in weight and strength.
Comparative Example 16
S~
- 12~ -
80 ~ of a synthetic graphite powder having a
bulk density oE 0.15 g/cm3 under no load was mixed wi-th
20 ~ of the meso phase pitch ob-tained in -the third step
oE Example 36. The mix-ture was molded and carbonized in
-the same manner as in Example 7~ to obtain a carbon
mater:ial having a bulk density of 1.66 g/cm3.
Impregnation of this carbon material with
mesophase pitch and subsequent carbonization were repeat-
ed four times in the same manner as in Example 7~ to
obtain a carbon material having a bulk density of 1.92
g/cm3/
The carbon material had a flexural strength of
5~0 kg/~m . When the material was kept for 24 hours at
600 C in air, the material showed a 20 % reduction in
weight and became porous.
Comparative Example 17
The carbon material having a bulk density of
1.66 g/cm , obtained in comparative Example 16 was
covered with a metallic silicon powder and heated to 1500
C to effect melt impregnation, reaction and sintering to
obtain a carbon silicon carbide composite material. The
material had an improved flexural strength of 8.2 kg/mm2.
When the material was measured for Elexural strength at
1500 C in nitrogen, the material caused deformation
owing to the melting of unreacted silicon and showed a
reduced flexural strength of 3.0 kg/mm2.
Example 76
The same silicon-containing reaction product as
obtained in Example 30 (1) was used as a spinning material
and subjected to melt spinning at 360 C using a metallic
nozzle of 0.15 mm in diameter. The spun fiber was cured
at 300 C in air and pyrolyzed at 1300 c in an argon
a-tmosphere to obtain an inorganic fiber having a diameter
of 10 ~m.
The Eiber had a tensile strength of 295 kg/mm2
and a tensile modulus of elasticity of 26 t/mm2 and, when
- 122 -
i-ts breaking surface was observeci, clearly had a radial
structure.
When -the Eiber was sublected to -thermal oxida-
tion, ~here occurred substantially no weig~-t decrease up
to 700 C and, at 800 C, only 5 ~ of the total weight
was lost.
The inorganic fiber was used as a reinforcing
agent for an epoxy resin of bisphenol A type to obtain a
unidirectionally reinforced epoxy redin composite material
lQ (Vf: 60 ~). This composite material had flexural streng-
ths at 0 and 90 directions oE 195 kg/mm2 and 12.8
kg/mm2, respectively, which were far superior to the
flexural strengths at 0 and 90 directions of 100 kg/mm2
and 3.5 kg/mm2 possessed by a unidirectionally reinforced
epoxy resin composite material lVf: 60 %) using a conven-
~ional pitch-based carbon fiber having a tensile strength
of 280 kg/mm and a tensile modulus of elasticity of 55
t/mm .
Example 77
The precursor fiber (spun fiber) obtained in
Example 76 was cured at 300 C in air and then pyrolyzed
at 1400 C in an inert gas atmosphere to obtain an in-
organic Eiber of 9.5 ~m in diameter. Observation by a
transmission electron microscope indicated that, in the
inorganic fiber, amorphous SiC and ~-SiC crystallites
were uniformly dispersed in crystalline carbon.
The inorganic fiber consisted of a radial
structure and partially a random structure and had a
tensile strength of 232 kg/mm2 and a tensile modulus of
elasticity of 30 t/mm2.
The inorganic fiber was used as a reinforcing
agent for an epoxy resin of bisphenol A type to obtain a
unidirectionally reinEorced epoxy resin composite material
(Vf; 60 %). This composite material had flexural streng-
ths at 0 and 90 directions of 150 kg/mm2 and 6.8kg/mm2, respectively.
r-~
-- 123 --
Examples 78-80
(A) The residue (the 40-g residue) used in
Example 30 (1) and obtained by mel-ting the reac-tion
produc-t obtained in the first step of Example 1 and
allowing it to stand at 300 C to remove the light por-
tion by means of specific rgavity difference [the residue
is hereinaf-ter referred to as the polymer (a)] and (~
the 95 % meso phase pitch obtained in the second step of
Example 1 were melt mixed at various ratios at various
temperatures to obtain three uniform silicon~-containing
reaction products. These reaction products were made
into inorganic Eibers in the same manner as in Example
76. The inorganic fibers were measured for mechanical
properties. The results are shown in Table 5.
Table 5
_ _ _ I ~ I
olymer ~eso~ Mix- Mix- ~ylene ~ia- ~'ensil ~ensil
(a) ?hase ing ng insolu- ~e-ter strength ~odulus of
?itch t.emp. time ble 2 ~lasticity
_ __ (g) (g) (C) ~h) content (~m) (kg/mm ) (t/mm)
~mple 78 20 100 360 1 79 11 256 23
~mple 79 60 60 320 1.5 45 12 238 18
~mple 80 BO 40 300 1.5 25 12 200 15
Example 81
The same silicon-containing reaction product as
obtained in Example 10 (3) was used as a spinning material
2Q and subjected to melt spinning at 360 C using a metallic
nozzle of 0.15 mm in diameter. The resulting spun fiber
was oxidized and cured at 300 C in air and -then pyrolyzed
at 1300 C in an argon atomosphere to obtain an inorganic
fiber of 8 ~m in diameter.
-- 124 --
This inorganic fiber had a tensile strength of
320 kg/mm~ and a tensile modulus of elas-tici-~y of 26
t/mm2 ancl, when its breaking surface was observed, had a
radial s~ructure
The inorganic fiber was ground, subjected to
alkali fusion and a hydrochloric acid treatment, dissolved
in water, and then subjected to high frequency plasma
emission spectrochemical analysis ~ICP). As a result,
the inroganic fiber had a silicon content oE 0.95 ~.
The inorganic Eiber was oxidized in air wlth
heating. No decrease in mechanical properties was seen
even at 600 C. Thus, it was confirmed that the in-
organic fiber was superior in oxidation resistance to
commercially available carbon fibers which were burnt out
15 at 600 c.
The inorganic fiber was used-as a reinforcing
agent for an epoxy resin of bisphenol ~ type to obtain a
unidirectionally reinforced epoxy resin composite
material (Vf: 60 %). This composite material had flexural
20 strengths at 0 and 90 directions of 210 kg/mm2 and
13.2 kg/mm2, respectively, which were far superior to
the flexural strengths at 0 and 90 directions of 100
kg/mm2 and 3.5 kg/mm2 possessed by a unidirectionally
reinforced epoxy resin composite matirial (Vf: 60 %~
using a conventional pitch-based carbon fiber having a
tensile strength of 280 kg/mm2 and a tensile modulus of
elasticity of 55 t/mm2.
Example 82
The precursor fiber (spun fiber) obtained in
Example 81 was cured at 300 C in air and then pyrolyzed
at 2400 C in an inert gas atmosphere to obtain an in-
organic fiber of 7.1 ~m in diameter. Observation by a
transmission electron microscope indicated that, in the
inorganic fiber, ~-SiC crystallites were uniformly dis-
persed in crystalline graphite.
This inorganic fiber consisted of a radial
- 125 -
struc-ture and partially a random structure and had a
tensile s-trength of 340 kg/mm2 and a high tensile modulus
of elasticity of 55 t/mrn2.
The unidirectionally reinforcecl epoxy resin
(bisphenol ~ type) composite ma-terial (Vf: 60 %) using
the above inorganic -fiber as a reinjEorcing agent had
flexural strengths at O abd 90 directions oE 205
kg/mm2 and 6.0 kg/mm2, respectively.
Examples 83~-86
The reaction product obtained in the first step
of Example lO and the 75 % mesophase pitch obtained in
the second step of Example 10 were melt mixed at various
ra-tios at various temperatures to obtain four uniform
silicon-containing reaction products. These reaction
products were made into inorganic -'ibers in the same
manner as in Example 81. The inorganic fibers were
measured for mechanical proper-ties. The results are
shown in Table 6.
Table 6
~eac- Meso- Mix- ~ix- Silicon In- 3ia- Tensil Tensil
ion phase ing ng content solu- ~e-ter strength ~dulus
?ro pitch temp. ime ble ~f
luct elasti-
(g) (g) (C) (h) (%) (%) (~m) (kg/mm2) (Ct/mm2)
__ _
Example 83 20 100 360 1 2. 48 61 8 310 24
Example 84 60 60 3501.5 7.44 35.5 11 260 18
Example 85 80 40 3401.5 10.01 25 12 210 15
_ __ . _ _
Example 86 3 97 400 1 0.47 71 8 315 28
* The r_action product obtained in the first step
- 126 -
Example 87
100 par-ts oE a bisphenol A type epoxy resin (XB
2879 A manufactured by Ciba Geigy Co.) and 20 parts of a
dlcyandiamide curing agent (XB2879B manufac-tured by Ciba
Geigy Co.) were mixed uniformly. The mixture was dissolv-
ed in a mixed solvent of me-thyl cellosolve and acetone
(1:1 by weight) to prepare a solution containing 28 ~ of
the mixture.
The inorganic fiber havlng a silicon content of
0-95 ~, obtained in the first half of Example 81 (the
fiber is hereinafter referred to as the inorganic fiber
I1 was impregnated with the above solution and then taken
off in one direction using a drum winder, and heated for
14 minutes at 100 C in a heat circulation oven to prepare
prepregs of half-cured inorganic fibers arranged uni-
directionally. The prepregs had a fiber content of 60
by volume and a thickness of 0.15 mm.
10 sheets of the prepregs were laminated with
the $ibers arranged unidirectionally, and press molded at
7kg/cm for 4 hours at 170 C to obtain a unidirectional-
ly reinforced epoxy resin composite matrial of 250 mm x
250 mm.
A test sample of 1.27 mm (width) x 85 mm (length)
x 2 mm (thickness~ for measurement oE flexural strength
was cut out from the above composite material. Using the
test sample, a three-point bending test (span/width = 32)
was conducted at a speed of 2 mm/min. The mechanical
properties of the above composite material are shown
below.
Tensile strength (kg/mm2) 170
Tensile modulus of elasticity (t/mm2) 16
Flexural strength (kg/mm2 232
Flexural modulus of elasticity (t/mm2) 16
~ensile strength in direction perpendicular
to fiber (kg/mm2) 6.7
Tensile modulus of elastici-ty in direction
- 127 -
perpendicular to fiber (t/mm2~ 5.1
Flexural strength in direction perpendicular
to fiber (kg/mm2) 9.2
Flexural modulus of elas-ticity in direction
perpendicular to fiber (t/mm2~ 5.0
Interlaminar shear strength (kg/mm2) 9.0
Flexural shock (kg.cm/mm2) 255-
Comparative Example 18
A carbon fiber-reinforced epoxy resin composite
ma-tirial was produced in the same manner as in Example 87
: except that the inorganic fiber I was replaced by a high
modulus pitch-based carbon fiber having a tensile strength
of 280 kg/mm2, a tensile modulus of elasticity of 55
t/mm2 and a diameter of 10 ~. The composite material had
a fiber content of 60 ~ by volume. The mechanical proper-
ties of the composite material are shown below.
Tensile strength (kg/mm2) 150
Tensile modulus of elasticity (t/mm ) 23
Flexural strength (kg/mm2 100
Flexural modulus of elasticity (t/mm2) 12
Tensile strength in direction perpendicular
to fiber (kg/mm2) 3.0
Tensile modulus of elasticity in direction
perpendicular to fiber (t/mm2) 0.5
Flexural strength in direction perpendicular
to fiber (kg/mm2) 3.5
Flexural modulus of elasticity in direction
perpendicular to fiber (t/mm2) 0.5
Interlaminar shear strength (kg/mm2) 7.5
Flexural shock (kg.cm/mm2) 70
Comparative Example 19
A carbon fiber-reinforced epoxy resin composite
matirial was produced in the same manner as in Example 87
except that the inorganic fiber I was replaced by a
surface-treated high strength PAN-based carbon fiber
having a tensile strength of 300 kg/mm2, a tensile modu-
S~
- 128 -
lus of elasticity of 21 t/mm ancl a diameter of 7.5 ~.
The composite material had a fiber content of 60 ~ by
volume and the Eollowing mechanical properties.
Tensile strength ~kg/mm ) 172
Tensile modulus of elasticity tt/mm ) 14
Flexural strength ~kg/~m 170
Flexural modulus of elasticity (t/mm ) 13
Tensile strength in direction perpendicular
to fiber (kg/mm ) 4.5
Tensile modulus of elasticity in direction
perpendicular to fiber (t/mm ) 0.88
Flexural strength in direction perpendicular
to fiber (kg/mm ) 6.2
Flexural modulus of elasticity in deraction
perpendicular to fiber (t/mm ) 0.87
Interlaminar shear strength (kg/mm ) 8.1
Flexural shock (kg.cm/mm ) 150
Example 8~
(1) 3 g of the reaction product obtained in Example
10 (1) and 97 g of the meso phase pitch obtained in
Example 10 (2) were melt mixed for 1 hour at 400 c in a
nitrogen atrmosphere to obtain a uniform silicon-contain-
ing reaction product. This reaction product had a melt-
ing point of 272 C, a softening point of 319 C and a
5 xylene insoluble content of 71 %.
The reaction product was used as a spinning
material and subjected to melt spinning at 3~0 c using a
metallic nozzle of 0.15 mm in diameter. The spun fiber
was cured at 300 C in air and pyrolyzed at 2000 c in an0 argon atmosphere to obtain an inorganic fiber II having
diameter of 7.3 ~.
The inorganic fiber II had a tensile strength
of 325 kg/mm and a high tensile modulus of elasticity of
41 t/mm .
The inorganic fiber II was ground, subjected to
alkali fusion and then to a hydrochloric acid treatment,
- 1~9 -
and dissolved in wa-ter~ The resul-ting aqueous solution
was subjected to high frequency plasma emission spectro-
chemical analysis~ ~s a result, the inorganic fiber TI
had a silicon content oE 0.~7 %.
(2) The same procedure as in Example 87 was repeat-
ed excep-t that -the inorganic fiber I was replaced by the
inorganic Eiber II and the epoxy resin was replaced by a
commercially available unsaturated polyester resin, to
obtain an inorganic Eiber-reinforced polyester composite
material having a Eiber content of 58 % by volume. This
composite material had the following mechanical properties.
Tensile strength Ikgfmm ) 161
Tensile modulus of elas-ticity (t/mm ) 21
Flexural strength (kg/mm2 23~
Flexural modulus of elastici-ty (t/mm ) 205
Tensile strength in direction perpendicular
to fiber (kg/mm2) 6.2
Tensile modulus oE elasticity in direction
perpendicular to fiber (t/mm2) 5.5
Flexural strength in direction perpendicular
to fiber (kg/mm2) 9.1
Flexural modulus of elasticity in direction
perpendicular to fiber (t/mm ) 8.7
Interlaminar shear strength (kg/mm2) 9.0
Flexural shock (kg.cm/mm2) 251
Example 89
The same procedure as in Example 87 was repeat-
ed except that the epoxy resin was replaced by a poly-
imide resin manufactured by Ube Industries, Ltd., to
obtain an inorganic fiber-reinforced polyimide composite
material having a fiber content of 60 % by volume.
The composite material had the following mecha-
nical properties.
Tensile strength (kg/mm2) 162
Tensile modulus of elasticity (t/mm ) 16
Flexural strength (kg/mm2 230
- 130 -
Flexural modulus of ela.sticity ~t/mm ) 16
Tensile strength in direction perpendicular
to fiber (kg/mm 1 6.3
Tensile modulus of elasticity in direction
perpendicular to :Eiber ~t/mm2) 4.9
E'lexural strength in direction perpendicular
-to fiber (kg/mm2) 8.9
Flexural modulus of elast.icity in direction
perpendicular to fiber (t/mm2) 5.0
Interlaminar shear strength (kg/mm2) 9.0
Flexural shock (kg.cm/~n2) 2Sl
Example 90
100 parts of a bisphenol A type epoxy resin
(XB2879A manufactured by Ciba Geigy Co.) and 20 parts of
a dicyandiamide curing agent tXB2879B manufactured by
Ciba Geigy Co.) were mixed uniformly. The mixture was
dissolved in a mi~ea solvent of methyl cellosolve and
acetone (1:1 by weight) to prepare a solution containing
2~ ~ of the mixture.
The same inorganic fiber I as used in Example
87 was impregnated with the above solution and then
taken off in one direction using a drum winder, and
heatedf for 14 minutes at 100 C in a heat circulation
oven to prepare prepreg sheets of halfcured inorganic
fibers arranged unidirectionally. Separately, a surface-
treated carbon fiber (a PAN-based carbon fiber having a
diameter of 7 ~, a tensile strength of 300 kg/mm2 and a
tensile modulus of elasticity of 24 t/mm2) was subjected
to the same treatment as above, to prepare prepreg sheets0 of half-cured carbon fibers arranged unidirectionally.
The inorganic fiber prepreg sheets and the
carbon fiber prepreg sheets were laminated by turns with
the fibers arranged in one same direction and then hot
pressed to obtain a hydrid fiber (inorganic fiber/carbon
fiber)-reinforced epoxy resing composite material.
The composite material had a fiber content of
t~
- 131 -
60 % by volume (content of inorganic Eiber = 30 % by
volume and conten~ of carbon fiber = 30 % by volume).
The composite material had a tensile strength,
a t:ensile modulus of elasticity and a flexural strength
of 1~5 kg/mm2, 16.3 t~mm2 and 185 kg/mm2, respectively,
at a 0 direction, a flexural strength of ~.3 kg/mm2 at
a 90 direction, an interlaminar shear strength of 8.1
kg/mm2 and a Elexural shock of 22~ kg.cm/cm2.
Example 91
(1) 100 parts of a polydimethylsilane obtained by
subjecting dimethylchlorosilane -to dechlorination conden-
sation with me-tallic sodium was mixed with 3 parts of a
polyborosiloxane. The mixture was condensed at 350 C in
nitrogen to prepare a polycarbosilane having a main chain
consisting mainly of a carbosilane unit represented by
the formula (Si-CH2) (the silicon atom in the carbosilane
unit has a hydrogen atom and a methyl group bonded thereto).
This polycatbosilane was mixed with a titanium alkoxide,
and the mixture was subjected to crosslinking and polymeri-
zation and 340 C in nitrogen to obtain a polytitanocarbo-
silane consisting of 100 parts of the carbosilane unit
and 10 parts of a titanoxane unit represeented by the
formula (Ti-O). This polymer was melt spun, cured at 190
c in air and successively pyrolyzed at 1300 c in nitro-
gen to obtain an inorganic fiber composed mainly ofsilicon, titanium, carbon and oxygen (titanbium content =
3 ~) and having a diameter of 13 ~, a tensile strength of
310 kg/mm and a tensile modulus of elasticity of 16
t/mm2 (monofilament method). The inorganic fiber was a
Si-Ti-C-O fiber consisting of a mixed system of (A) an
amorphous portion consisting of Si, Ti, C and O, (B)
crystalline ultrafine particles each of about 50 ~ in
diameter, of ~-SiC, TiC, a ~-SiC-TiC solid solution and
TiCl x (O<x<l) and (C) an amorphous portion consisting of
SiO2 and Tio2.
(2) The same procedure as in Example 90 was repeat-
,3
- 132 -
ed except that the carbon flber was replaced by the
Si-Ti-C-O fiber obtained in (1) above, -to obtain a hydrid
fiber-reinforced epoxy resin composite materialO This
composite ma-terial had a -fiber content oE 60 gO by volume
(content of inorsanic fiber = 30 -~ by volume and content
of Si-Ti-C-O Eiber = 30 ~ by volume). The composite
material had a -tensile streng-th, a tensile modulus of
elasticity and a flexural strength of 198 kg/mm2, 15.1
t/mm2 and 195 kg/mm2, respectively, at a 0 direc-tion, a
Elexural strength of 12.0 kg/mm2 at a 90 direc-tion, an
interlaminar shear strength of 11.5 kg/mm2 and a flexural
shock of 280 kg.cm/cm .
Comparative Example 20
Using only a carbon fiber (PAN-based, diameter
= 7 ~) and in the same manner as in Example 90, there
were prepared prepreg shee-ts of half-cured carbon fibers
arranged unifirectionally.
These prepreg sheets were laminated, with the
fibers arranged in one same direction, and then hot
pressed to obtain a carbon fiber-reinforced epoxy resin
composite material. The composite material had afiber
content of 60 ~ by volume. The composite material had a
tensile strength, a tensile modulus of elasticity and a
flexural strength of 150 kg/mm2, 14 -t/mm2 and 172 kg/mm2,
respectively, at a 0 direction, a flexural strength of
6.2 kg/mm2 at a 90 direction, an interlaminar shear
strength of 8.1 kg/mm2 and a flexural shock of 150
kg,cm/cm2.
Comparative Example 21
Using only the Si-Ti-C-O fiber obtained in
Example 91 (1) and in the same manner as in Example9,
there were prepreg sheets of Si-Ti-C-o fibers. These
sheets were made into a Si-Ti-C-o fiber-reinforced epoxy
resin composite material in the same manner as in Com-
parative Example 20. The composite material had a fiber
conten-t of 60 gO by volume. The composite material had a
- 133 -
tensile modulus of elastici-ty of 11.3 t~mm . The other
mechanical strengths of the material were about the same
as those of Example 91.
Examples 92-9~
The same procedure as in Example 90 was repeat-
ed except that the carbon fiber was replaced by an alumina
fiber, a silicon carbide fiber or a glass fiber (their
properties are shown in Table 7. They are hereinafter
referred to as the second fiber for redinforcernen-t(s)),
to obtain hydrid fiber-reinforced epoxy resin composite
rnaterials. These composite fibers had a fiber content of
60 ~ by volume (inorganic fiber content = 30 % by volume,
content of second fiber for reinforcement = 3d % by
volume~.
The properties of the hydrid fiber-reinforced
epoxy resin composite materials are shown in Table ~.
Table 7
Second fiber for
~ reinforcement Alumina Silicon E-glass
Mechanical ~ fiber carbide fiber
Properties _ fiber
~iameter (~) 9 15 10
Tensile strength (kg/mm )260 280 180
_
Tensile modulus 2f 25 20 7
elasticity (t/mm )
.~. ~ t~ 5,3
- 134 -
Table 8
~ ~ Example Example Example Example¦
\ ~ 92 93 94 _
Second :Eiber
\ :Eor rein- Alumina Silicon E-glass
Mechanical \ Eorcement fiber carbide Eiber
Properties --________=_ _ Eiber _
Tenslle strength (kg/mm ) 160 192 157
Tensile modulus ~E
elasticity (t/mm ) 16 15 11
. _ __
Flexural strength (kg/mm ) 188 214 178
Flexural modulus~of14 18 11
elas-ticity ~t/mm~)
_ ~
Compre~sion strength185 191 165
Comparative Examples 22-24
Using an alumina fiber, a silicon carbide fiber
or a glass fiber and in the same manner as in Example 90,
-there were prepared alumina fibe prepreg sheets, silicon
carbide prepreg sheets and glass fiber prepreg sheets.
Using these prepreg sheets and in the same manner as in
Compatrative Example 20, there were prepared an alumina
fiber-reinforced epoxy resin composite material, a silicon
carbide fiber-reinforced epoxy resin composite material
and a glass :Eiber-reinforced epoxy resin composite
material, These composite ma-terials had a fiber content
of 60 % by volume.
f~ t~8
- 135 -
The mechanical properti.es of the composite
materials are shown in Table 9~ The mechanical proper-
-ties of the reinforclng second fi.bers us2d are shown in
Table 7.
Table 9
..._ Compara- ~ompara- Compara~
\ ~ Example tive Live tive
\ ~ Example xample Exa24mPle
\ Second fiber _ _
\ for rein- Al.umina Silicon E-glass
Mechanical \ force- fiber carbide fiber
Properties ~ ment fiber
Tensile strength (kg/mm2) 130 170 120
_
Tensile modulus ~f
elasticity (t/mm ) 14 12 4.5
Flexural strength (kg/mm2) 160 193 120
. _
Flexural modulus2of12 5 9 7 4 2
elasticity (t/mm )
(kg/Pmm~) 9 170 160 46
Example 95
Using, as reinforcing fibers, the inorganic
fiber II and a silicon carbide fiber using carbon as its
core, having a diameter of 140 ~l, a tensile strength of
350 kg/mm and a tensile modulus of elasticity and in the
same mann~r as in Example 90, there was prepared a hydrid
fiber-reinforced epoxy resin composite material. The
composite material had a fiber content of 4~ % by volume
(inorganic fibe II content = 30 ~ by volume, content of
silicon carbide fibe using carbon as its core = 15 % by
g q ~ ,~ r~ ~,
- 136 -
volume).
The composite material had a tensile strength,
a tensile modulus oE elastici-ty and a flexural strength
- of 165 Icg/mm2, 25 t/mm2 and 210 kg/mm2, respec-tively~ at
a 0 direction and a flexural strength of 6.1 kg/mm2 a-t
a 90 direction.
Compara-tive Example 25
Using the silicon carbide fiber using carbon as
its core, used in Exmaple 90 and in the same manner as in
Example 90, there were prepared prepreg sheets of silicon
carbide Eiber using carbon as it core. Using these
prepreg sheets and in the same manner as in Comparative
~xample 20, there was obtained an epoxy resin composi-te
material reinforced with a silicon carbide Eiber using
carbon as its core. The composite material had a fiber
content of only 33 % by volume becouse the silicon carbide
fiber using carbon as lts core had a large diameter.
The composite material had a tensile strength,
a tendile modulus of elasticity and a flexural strength
of 140 kg/mm2, 23 t/mm2 and 195 kg/mm2 at a 90 direc-
tion.
Example 96
Using, as reinforcing fibers, the inorganic
fiber II and a boron fiber having a diameter of 140 ~, a
tensile strength of 357 kg/mm and a tensile modulus of
elasticity of elasticity of 41 t/mm2 and in the same
: manner as in Example 90, there was prepared a hydrid
fiber-reinforced epoxy resin composite material. This
composite material had a fiber content of 50 ~ by volume
(inorganic fiber II content = 30 ~ by volume, boron fiber
content = 20 ~ by volume).
The composite material had a tensile strength,
a tensile modulus of elasticity and a -flexural strength
oE 175 kg/mm2, 25 t/mm2 and 210 kg/mm2, respectively, at
a 0 direction and a flexural streng-th of 5.8 kg/mm2 at a
90 direction.
- 137 -
Comparative ExampLe 26
~ sing only the boron Eiber used in Example 96
and in the same manner as in Example 90, there were
prepared boron Eiber prepreg sheet:s. Then, a boron
fibeer-reinforced epoxy resin composite material was
obtained in -the same manner as in Comparative Example 20.
The composite material had a fibeer conten-t of only 31
by volume because the boron fiber had a large diameter.
The composite material had a tensile strength, a tensile
modulus of elas-ticity andd a flexural strength of 154
kg/mrn2, 22 t/mm2 and 193 kg/mm2, respectively, at a 0
directior- and a Elexural strength or 3.8 kg/mm2 a-t a 90
direction.
Example 97
The same procedure as in Example 90 was repeat-
ed except that the carbon fiber was replaced by an aramid
fiber having a tensile strength of 270 kg/mm2 and a
tensile modulus of elasticity of 13 t/mm2, to obtain a
hydrid fiber-reinforced epoxy resin composite material.
The composite material had a fiber content of 60 % by
volume (inorganic fiber content = 30 3 by volume, aramid
fiber content = 30 % by volume).
The composite material had a tensile strength,
a tensile modulus of elastlcity and a flexural strength
f 156 kg/mm2, 12 t/mm2 and 158 kg/mm2, respective]y, at
a Q direction and was significantly improved in strength
and elastic modulus as compared with an aramid fiber-
reinforced epoxy resin having a fiber content of 60 % by
volume had a tensile strength, a tensile modulus of
elasticity and a flexural strength of 95 kg/mm2, 5.3
t/mm2 and 93 kg/mm2, respectively, at a 0 direction.
The above composite material also had a flexural shock of
276 kg.cm/cm2 and did not substantially reduce the shock
resis-tance of the aramid fiber which characterizes the
fiber. (An aramid fiber-reinforced epoxy resin having a
Eiber con-tent o-E 60 % by volume had a flexural shock of
3 ~
- l38 --
302 kg.cm/cm r )
Example 98
To a ~-SiC powder having an average partiele
diameter of 0.2 ~m were added 3 ~ Gf boron carbide and lO
~ oE a polytitanocarbosilalle powder, and -they were through-
ly rnixed. This mixture and a bundle of the inorganie
fibers I of 50 mm in length uniformly arranged in one
direetion were laminated by -turns fo that the inorganic
fiber I content in the resulting laminate became ~0 % by
volume. The resultinq laminate was press molded at 500
kg/cm in a mold. The molded material obtained was
heated to 1950 C in an argon atmosphere at a rate oE 200
C/hr and kept at that temperature for 1 hour to obtain
an inorganic Eiber-reinforced silieon earbide eomposite
sintered material.
Comparative Example 27
~l) Dimethyldiehlorosilane was subjeeted to deehlori-
nation eondensation with metallic sodium -to syn-thesize a
polydimethylsilane. lO0 parts by weight of the polydi--
methylsilane and 3 parts by weight of a polyborosiloxanewere mixed, and the mixture was subjected to eondensation
at 3~0 C in nitrogen to obtain a polycarbosilane having
a main ehain eonsisting mainly of a carbosilane uni-t
represented by the formula (Si-H) (the silieon atom of
the earbosilane unit has a hydrogen atom and a methyl
group bonded thereto). The polyearbosilane was melt
spun, eured at l90 C in air, and suecessively pyrolyzed
at 1300 C in nitrogen to obtain a silicon earbide fiber
eomposed mainly of Si, C and O, having a diameter of 13
~, a tensile strength oE 300 kg/mm and a tensile modulus
of elasticity of 16 t/mm .
(2) The same procedure as in Example 98 was repeat--
ed except that the inorganie fiber I was replaced by the
silicon carbide fiber produeed only frorn a polyearbosilane
in (l) above, to obtain a silicon carbide Eiber-reinforeed
silicon carbide composite sintered material.
-- 139 -`
Comparative Example 28
~ sing a commercially available PAN-based carbon
Eiber having a diame-ter oE 7.0 ~m, a tensile strength o
300 kg/mm and a tensile modulus of elasticity of 21
t/mm and in the same manner as in Example 98~ there was
obtained a carbon fiber-reinforced silicon carbide com-
posite sintered material.
Comparative Example 29
The same procedure as in Example 98 was repeat-
ed excep-t that neither inorganic fiber nor polytianocarbo-
silane powder was used, to obtain a silicon carbide
sintered material.
Example 99
(1) The same spinning material as used in Example
15 88 ~1) was melt spun at 360 C using a me-tallic nozzle of
0.15 mm in diameter. The spun fiber was oxidized and
cured at 300 C in air and pyrolyzed at 2500 C in an
argon atmosphere to obtain an inorganic fiber III having
a diameter of 7.2 ~.
This fiber had a tensile strength of 335 kg/mm
and a tensile modulus of elasticity of 53 t/mm2.
The inorganic fiber III was ground, subjected
to alkali fusion and then to a hydrochloric acid treatment,
dissolved in water and then subjected to high frequency
plasma spectrochemical analysis. As a result, the in-
organic fiber III had a silicon content of 0.42 ~.
(2) The same procedure as in Example 98 was repeat
ed except that the inorganic fiber III was used as a
reinforcing fiber, to obtain an inorganic fiber-reinEorc-
ed silicon carbide composite sintered material.
The mechanical strengths of the sinteredmaterials obtained in Example 93 and 99 and Comparative
E~amples 27-29 are shown in Table 10. In Table 10
Elexural s-trength is a value when the measurement was
made at a direction perpendicular to fiber.
~¢~
- 140 -
Table lO
Frexural strength (kg/mm ) ~ Reduction Deterio-
_ _ _ Kic in flexu- ration
ratio ral st- rate
Room 800 C 1400 C rength (1950 ~)
temp. (in air) (in nitrogen (800 C) (kg~m
___ _ _ _ ~ _ (~) sec )
EYample 98 57 48 645.l 5 OolO
Comparative 15 _ _ _ _
~ple 27 _ _ _
Comparative 42 20 502.5 2S
Example 27
_ _ _ _
O~xrative 50 53 55 _ 70
_ _
Example 99 63 53 69 4.0 O.08
Example lO0
An X-Si3N4 powder having an average particle
diameter of 0.5 ~m was thoroughly mixed with 2 % of
alumina, 3 ~ of yttria and 3 % of aluminum nitride. The
resulting powder and a bundle of the inorganic fibers I
of 50 mm in length arranged in one direction were laminat-
ed by turns so that the fiber content in the resulting
laminate became about lO % by volume. At this time, the
inorganic fibers I were laminated in two directions of 0
and 90 ~ The laminate was pressed for 30 minutes at 300
kg/cm2 at 1750 C to obtain an inorganic fiber-reinforced
silicon nitride composite sintered material.
The Elexural streng-th at room temperature and
1400 C, etc. of the sintered material are shown in Table
11 .
Comparative Example 30
The same procedure as in Example 100 was repeat-
ed except that no inorganic fiber I was used, to obtain a
sintered material. The results are shown in Table 11.
Table 11
_ Flexural ~trength _ Deterio-
(kg/mn ) Reduction ration
Kic in flexural rate
ratio strength (1750~;)
Room (1200 C) (kg~
temp.1400 C (%) sec )
Example 100 125 76 2.2 0.20
Comparative 120 45 _ 55
Example 30
_
10 Example 101
To a powder (average particle diameter = 44 ,um)
of a borosilicate glass (7740 manufactured by Corning
Glass Works) were added 45 g6 by volume of chopped fibers
of 10 mm in length obtained by cutting the inorganic
15 fiber 1. They were thoroughly dispersed in isopropyl
alcohol to obtain a slurry. This slurry and a bundle of
the inorganic fibers I arranged in one direction were
laminated by turns, dried and hot pressed at 750 kg/cm
for about 10 minutes at 1300 C in an argon atmosphere to
20 obtain an inorganic fiber-reinforced glass composite
material. The results are shown in Table 12.
Comparative Example 31
The same procedure as in Example 101 was repeat-
ed except that the inorganic fiber I was replaced by a
25 commercially available silicon carbide fiber, to obtain a
~t~ ?~
~ 2
glass ceramic. The resul~s are shown in Table ]2.
Table 12
_ Flexural ~trer.gth _ _ ~eterioration
(]~g/mm ) Reduc-tion rate
Kic in Ele~Yural (1300 C)
(R~l~emperature) ratio strerlgth ~kg/~m2 seC-l
(kg/mm ) ('300 C) (~
._ _ __ __ _ _ ___
E~ample 101 21.0 4 8 3 O.2
__ ~
Comparative
Example 31 14.2 4 _ 1O50
..._ _
Example 102
An alumina powder having an average particle
diameter of 0.5 ~m was mixed with 2 ~ by weight of tita-
nium oxide. To the mixture was added 15 ~ by volume of a
spun Eiber of a silicon-containing reaction product ~this
spun fiber was a precursor of the inorganic fiber I), and
ln they were thoroghly mixed in an alumina-made ball millO
The precursor fiber had an average leng-th of about 0.5
mm. The mixture was sintered at 2000 c in an argon
atmosphere using a hot press. The resulting sintered
material was subjected -to a spalling test. Tha-t is, the
sintered material was made into a shape of plate (40 mm x
10 mm x 3 mm); the plate was rapidly heated for 20 minutes
in a nitrogen atmosphere in an oven of 1300 ~C; then, the
plate was -taken out and subjected to forced air cooling
Eor 20 minutes; this cycle was repeated until cracks
appeared; thus, the cycle number in which cracks first
appeared was examined.
The cycle number and mechanical strength of the
sintered material are shown in Table 13.
Comparative Example 32
The same procedure as in Example 102 was repeat-
ed except that no precursor fiber was used, to obtain a
- 1~3 -
sintered material.
The results are shown i.n Table 13
Table 13
_ _ _ Reduction
Kic ratio in flexural Spalling test
strength (cycle number)
t800 C) ~%)
__ ~ _ _~
Example 102 2.5 5
. . .
Comparative _ 90
Example 32
Example 103
A plain weave fabric of the inorganic fiber I
used in Example 87 was immersed in a methanol solution of
a resol type phenolic resin (MRW 3000 manufactured by
~eiwa Kasei K.K.), pulled up, subjected to methanol
removal and dried to obtain a prepreg sheet. The prepreg
sheet was cut into square sheets of 5 cm x 5 cm;; the
square sheets were piled up in a mold and pressed at 50
kg/cm at 200 C to cure the phenolic resin to obtain a
molded material. The molded material was buried in a
carbon powder and heated to 1000 C a-t a rate of 5 C/h
in a nitrogen current to obtain an inorganic fiber-
reinforced carbon composite material. The composite
material was a porous material having a bulk density of
1.22 g/cm .
This compostie material was mi~ed with the
mesophase pitch powder obtained in Example 1 (2), melted
at 350 C in a nitrogen atmosphere in an autoclave, made
vacuum to effect impregnation of the pores of the com-
posite material with the mesophase pitch, pressurized at
a 100 kg/cm2 to fur-ther effect impregnation, heated to
300 C at a rate of 5 C/h for curing, and carbonized at
1300 C. This impregnation with mesophase pitch and
f~ Si~
carboni~ation procedure was repeated three more times to
obtain a composite ma-tirial having a bulk density of 1.85
g/cm and a flexural strength oE 37 kg/mm~. The composite
ma-terial had a fiber content (Vf~ of 60 % by volume~ ~Vf
was 60 ~ by volume also in the following Example 10~.)
Example 104
A graphite powder having an average particle
diameter of 0.2 ~m arld -the same mesophase pitch powder as
used in Example 103 were mixed at a 1:1 weight ratio.
The resulting mixed powder and the fabric of the in-
organic fiber III obtained in Example 99 (1) were laminat-
ed by turns and pressed at 100 kg/cm2 at 350 C to obtain
a molded material. This molded material was subjected to
four times of impregnation with mesophase pitch and
carboniæation in the same manner as in Exmple 103, to
obtain a composite material having a bulk densi-ty of 1.92
g/cm3 and a flexural strength of 41 kg/mm2. When the
compos-tite material was heated to 2500 ~C in an argon
atmosphere to graphitize the matrix, the flexural strength
of the composite material improved to 51 kg/mm2.
Comparative Example 33
The same procedure as in Example 103 was repeat-
ed except that there was used a commercially availlable
P~N-based carbon fiber having a diameter of 7 ~m, a
tensile strength of 300 kg/mm2 and a tensile modulus of
elasticity of 21 t/mm2, to obtain a composite material.
The composite material had a bulk densLty of 1.83 g/cm3
and a flexural strength of 21 kg/mm2.
Comparative Example 34
Impregnation with mesophase pitch and carboniza-
tion at 1300 C were repeated four times in ths same
manner as in Example 104 e~cept that there was used a
fabric of the silicon carbide fiber obtained in Compara-
tive Example 27 (1), to obtain a co~posite material. The
composite material had a flexural strength of 29 kg/mm2.
When this material was fur-ther pyrolyzed at 2500 ~C, the
.;8
- 145 -
flexural strength decreased to 9 kg/mm2 and the fiber
reinforcement effect: was lost completely
Example 105
(1~ To 57.4 g of the reac}ion p{oduct of Example 10
~1~ was added 15.5 9 of a xylene solution containing 25
(3.87 g) of tetraoctoxytitanium ~Ti(OC8H17)4]. After
distilling off xylene, the residue was reacted for 1 hour
at 340C to obtain 56 g of a reaction product.
The reaction product and the mesophase pitch
obtained in Example 10 (2) were melt mixed at a ratio of
1:1 at 380C in a nitrogen atmosphere to obtain a polymer
II.
(23 A two-dimensional plain weave fabric of the
same inorganic fiber I as used in Example 87 was cut into
discs of 7 cm in diameter. The discs were impregnated
with a xylene slurry containing 30 ~ of the polymer II
and dried to prepare prepreg sheets. In a mold, these
prepreg sheets were laminated in a total number of 30
with the fine powder of the polymer II being packed
between each two neighboring sheets and with the fiber
direction of a sheet differing from that of the lower
sheet by 45, and hot pressed at 350C at a pressure of
50 kg/cm2 to obtain a disc-like molded material. This
molded material was buried in a carbon powder bed for
shape retention and heated to 800C at a rate of 5C/h in
a nitrogen current and then to 1300C to carbonize the
matrix. The resulting composite material had a bulk
density of 1.19 g~cm3.
The composite material was immersed in a xylene
slurry containing 50 ~ of the polymer II; the system was
heated to 350C under reduced pressure while distilling
off xylene; then, a pressure of 100 kg/cm2 was applied to
effect impregnation. Thereafter, the impregnated com-
posite material was heated to 300C in air at a rate of
5C~h for curing and carbonized at 1300C~ This im-
preynation and carbonization procedure was repeated three
r j
~ 146 ~
more times to obtain a composite material having a bulk
density of l.96 g/cm3~ The composite material had a
Elexural strength of 57 kg~mm2
Example 106
(13 To 39 g of the reaction product of Example lO
(13 was added an e~hanol-xylene solution containing 1.5 %
(5.4 g) of tetrakisacetylacetonatozirconium. After
distilling off xylene, the residue was reacted for l hour
at 250~C to obtain 39.5 g of a reaction product.
The reaction product and the same mesophase
pitch as mentioned above were melt mixed at a l:l ratio
at 380C in a nitrogen atmosphere to obtain a polymer
III.
(2) The polymer III was prefired at l300C in
nitrogen to obtain an inorganic material. 50 9 of this
inorganic material was mixed with 50 g of a powder of the
polymer III. The resulting mixture and a two-dimensional
plain weave fabric of the inorganic fiber III obtained in
Example 99 tl1 were piled up by turns and hot pressed at
400DC at lO0 kg/cm2 to obtain a molded material~ The
molded material was carboniæed in the same manner as in
Example 105. The resulting material was subjected to
four times of ta) impregnation with the polymer III and
~b) carbonization, in the same manner as in Exa~ple l.
The resulting composite material had a bulk density of
2.03 g/cm3 and a flexural strength of 58 kg~mm2. When
the composite material was pyrolyzed at 2200C in argon
the bulk density and flexural strength improved to 2.06
g~cm3 and 63 kg~mm2, respectively.
Example 107
(l) The procedure of Example lO tl) was repeated
except that the amounts of the reforming pitch and
organosilicon polymer used were changed to 60 g and 40 g,
respectively, to obtain 57 g of a reaction product.
To 40 g of this reaction product was added an
ethanol-xylene solution containing 7.2 g (1.5 ~) of
- 147 -
harfnium chloride. After disti;Lling off xylene, the
residue was polymerized ~or 1 hour at 250C to obtain
43.5 g of a xeaction product.
The reaction product and the ~ame mesophase
pitch as mentioned above were melt mixed at a 1:1 ratio
at 380C in a nitrogen atmosphere to obtain a polymer IV.
(2) The procedure of Example 105 was repeated
except that the polymer IV was used as a polymer for
production of prepreg sheets, a polymer kor mold packing
and a polymer for impregnation, to obtain a composite
material. The composite material had a bulk density of
2.10 g~cm3 and a flexural strength of 54 kg/mm2.
Comparative ~xample 35
A carbon fiber-reinforced carhon material was
obtained in the same manner as in Example 105 except that
the inorganic fiber III as an reinforcing fiber was
replaced by a commercially available PAN-ba~ed carbon
fiber having a fiber diameter of 7 ~m, a tensile strength
of 300 kg~mm2 and a tensile modulus of elasticity of 21
t/mm2 and the polymer III was replaced by a petroleum-
based heat treated pitch having a softening point of
150C and a carbon residue of 60 %. This material had a
low bulk density of 1.67 g~cm3 and a flexural strength of
lS kg/mm .
Comparative Example 36
The silicon carbide fiber obtained in Com-
parative Example 27 tl) and an equal weight mixture~ as a
matrix material, of (a) synthetic graphite having a bulk
density ~under no load) of 0.15 g/cm3 and (b) the same
pitch powder as used in Comparative Example 35, were
subjected to hot pressing in the same manner as in
Example 106 to obtain a molded material The molded
material was carbonized. The carbonized material was
subjected to four times of (a) impregnation with the
above pitch and (b) carbonization, to obtain a composite
material having a bulk density of 1.90 g/cm3 and a
r- ~3
-- 1~8 --
flex-lral strength of 21 kg/mm2. It was tried to
graphitize the composite material at 2200C, but the
reinforcing fiber deteriorated and the strength of the
composite material decreased to 5 kg/mm2
Example 108
The composite materials of Examples 105, 106
and 107 and Comparative ~xamples 35 and 36 were heated
for l hour in an air oven of 600C and then measured for
flexural strength. In the composite materials of
Comparative Examples 35 and 36, oxida~ive deterioration
took place to such an ex~ent as to allow no strength
measurement. In the composite materials of Examples 1059
106 and 108, there was seen no strength reduction.
Example 109
~l) 50 g of a reforming pitch was added to 50 g of
the organosilicon polymer obtained in Reference Example
l. The mixture was reacted for 4 hours at 4~0C to
obtain 48 g o a reaction productO
Separately, a reforming pitch was reacted for
4 hours at 430C to obtain a mesophase pitch.
The reaction product and the mesophase pitch
were melt mixed at equal weights to obtain a uniform
silicon containing reaction product. The reaction
product is hereinafter referred to as the polymer V.
(2) A two-dimensional plain weave fabric of the
inorganic fiber I obtained in Example 87 (l) wa~ cut into
discs having a diameter of 7 cm. The discs ~ere im-
pregnated with a xylene slurry containing 30 % of the
reaction product of Example lO (l) and dried to prepare
prepreg sheetsO In a mold, these prepreg sheets were
laminated in a total sheet number of 30 with the fine
powder of the matrix polymer V being packed between each
two neighboring sheets and with the fiber direction
(angle) of a sheet advanced from that of the lower sheet
by 45, and hot pressed at 350 at a pressure of 50
kg/cm to form a disc-like molded material. This molded
r-~
-- 149 --
material was buried in a carbon powder bed for shape
retention and heated to 800C at a rate of 5C/h in a
nitrogen current and then to 1300C to carbonize the
matrix. The resulting composite material had a bulk
density of 1.32 g~cm3.
The composi~e material was immersed in a xylene
slurry containing 50 ~ of the product of Example 10 ~
the system was heated to 350C under reduced pressure
while distilling oEf xylene; then, A pressure of 100
kgJmm2 was applied to effect impregnation. Thereafter,
the impregnated composite material ~as heated to 300~C in
air at a rate of 5C/h for curing and carbonized at
1300C. ~his impregnation and carboniæation procedure
was repeated three more times to obtain a material having
a bulk density of 1.95 g/cm3. ~he composite material had
a flexural strength of 55 kg/mm .
Example 110
The silicon-containing reaction product ob-
tained in Example 88 tl) was prefired at 1300C in
nitrogen to obtain an inorganic material. 50 parts of
this inorganic material and 50 parts of a powder of the
polymer V were mixed. The mixture and a two-dimensional
plain weave fabric of the inorganic fiber III obtained in
Example 99 tl) were piled up by turns and hot pressed at
400C at 100 kgJcm2 to obtain a molded material. The
molded material V was carbonized in the same manner as in
Example 109. The carbonized material was subjected to
four ~imes of ~a) impregnation with the polymer V and (b)
carbonization, in the same manner as in Example 109. The
resulting composite material had a bulk density of 2.02
g/cm3 and a flexural strength of 58 kg~mm2. When the
composite material was pyrolyzed at 2200C in argon, the
bulk density and flexural strength improved to 2.05 g~cm3
and 61 kgJmm , respectively.
Comparative Example 37
A carbon fiber-reinforced carbon material was
t~
- 150 -
obtained in the same manner as in Example 109 except that
the inorganic fiber I as a reinforcing fiber was chanqed
to a commercially available PAN-based carbon fiber having
a fiber diameter oE 7~m, a tensile strength of 300
kg/mm and a tensile modulus of elasticity of 21 t/mm2
and the polymer V was changed to a petroleum-based heat
treated pitch having a softening point of 150C and a
carbon residue of 60 %. The material had a low bulk
density of 1.67 g/cm and a Elexural strength of 15
~g/mm .
Comparative Example 38
The silicon carbide fiber obtained in
Comparative Example 27 (1~ and an equal weight mixture of
(a) snthetic graphite having a bulk density ~under no
load) of 0.15 g/cm3 and (b) a powder of the same pitch as
used in Comparative Example 37 were subjected to hot
pressing in the same manner as in Example 110 to obtain a
molded material. The molded material was carbonized and
then subjected to four times of (a) impregnation with the
above pitch and (b) carbonization, to obtain a composite
material having a bulk density of 1.90 g/cm3 and a
flexural strength of 21 kg/mm . It was tried to
graphitize the composite material at 2200C, but the
reinforcing fiber deteriorated and the strength decreased
to 5 kg/mm2.
Example 111
The composite materials of Examples 109 and
110, and Comparative Examples 37 and 38 were heated for
1 hour in an air oven of 600C and then measured for
flexural strength.
In the composite materials of Comparative
Examples 37 and 38, oxidative deterioration took place to
such an extent as to allow no strength measurement.
Meanwhile, in the composite material of Example 109,
strength reduction was only 5 % and in the composite
material of Example 110~ there was seen no strength
reduction.
i?
-- 151 --
Example 112
A fiber was produced using an apparatus of Fig.
lo
FigO 1 is a schematic illustration showing an
example of the apparatus used for production of a fiber
for use in the composite material of the present inven-
tion, wherein the numeral 1 is a treating tank, the
numeral 2 is an ultrasonic applicator, the numeral 3 is a
treating solution, the numeral 4 is a continuous fiber
bundle, the numerals 5 and 10 are bobbins, the numerals 6
and 7 are movable rollers, the numerals 8 and 9 are
pressure rollers, the numeral 11 is a blower, the numeral
12 is a drier and the numeral 13 is a stirrer.
250 g of silicon carbide fine particles
(average diameter: 0.28/~m) was placed in a treating tank
1 containing 5,000 cc of ethyl alcoholn Ultrasonic
vibration was applied by an ultrasonic applicator 2 to
suspend the silicon carbide fine particles in ethyl
alcohol and thereby to prepare a treating solution 3.
A continuous fiber bundle 4 of the same in-
organic fiber I as used in Example 87 was unwound from a
bobbin 5 and passed through a treating solution 3 with
the passing time controlled at about 15 sec by movable
rollers 6 and 7. ~During the passing, an ultrasonic wave
was applied to the treating solution 3 and the solution 3
was stirred with air being blown.) Then, the continuous
fiber bundle was pressed by pressure rollers 8 and 9,
wound up by a bobbin 10, and dried at room temperature in
air. In Fig. 1, the numerals 11 and 12 are a blower and
a drier, respectively, and are used as necessary. The
numeral 13 is a stirrer.
The fiber which had been black before the
treatment had a grayish green color after the treatment.
Weighing of the fiber after the treatment indicated that
6 % by volume of the fine particles attached to the
fiber.
- 152 -
Example 113
The same treatment as in Example 112 was re-
peated except that as the treating solution in the
treating tank 1 there was used a slurry ohtained by
suspending 100 g of silicon carbide whiskers (average
diameter: about 0.2~m, average length: about 100J~m~ and
250 g o silicon carbide fine particles (average particle
diameter: 0O28f~m) in 5,000 cc of ethyl alcohol.
The fiber which had been black before the
treatment had a grayish green color after the treatment.
Observation of the fiber after the treatment by an
electron microscope (SE~) indicated that mainly fine
particles attached to the surface of each continuous
fiber and further mainly whiskers attached thereonto.
Weighing of the fiber after the treatment indicated that
9 % by volume of the fine particles and whiskers attached
to the fiber.
Example 114
The same treatment as in Example 113 was re-
peated except that as the continuous fiber there was usedthe inorganic fiber II obtained in ~xample 88 ~1), to
obtain a fiber to which about 8 % of fine particles and
whiskers had attached.
Example 115
A continuous fiber bundle 4 of the inorganic
fiber I was treated in the same manner as in Example 112
except that as the treating solution there was used a
suspensln obtained by suspending 100 9 of silicon nitride
whiskers (average diameter: about 0.3/~m, average length:
30 about 200~ m) and 100 g of the above silicon carbide fine
particles in 5,000 cc of water. As a result, about 4 %
by volume of the fine particles and whiskers attached to
the continuous fine bundle 4.
Example 116
A continuous fiber bundle 4 of the inorganic
fiber I was passed through a suspension obtained by
- 153 -
stirring 100 9 of silicon carbide fine particles in 500
cc of ethanol, while applying am ultrasonic wave to the
suspensionO Then, the fiber bumdle was passed through a
suspension obtained by stirring 150 9 of silicon nitride
whiskers in 500 cc of ethanolr in the same manne~ and
dried. As a result, about 12 % by volume of the fine
partlcles and whiskers attached to the fiber bundle.
Example 117
The silicon-containing reaction product ob-
tained in the third step of Example 10 was finely groundand then pyrolyzed at 1300C in an argon current to
obtain a fine powder having an average particle diameter
of 0.5 m and consisting of crystalline carbon, amorphous
carbon and an amorphous material composed mainly of
Si-C-O. 100 g of this f ine powder was suspended in 500
cc of ethanol by stirring~ A continuous fiber bundle 4
of the inorganic fiber I was passed through the above
suspension while applying an ultrasonic wave to the
suspension. The fiber bundle was then passed through a
suspension obtained by suspending 150 g of silicon
nitride whiskers in 500 cc of ethanol by stirring, in the
same manner and dried. As a result, about 10 % by volume
of the f ine particles and whiskers attached to the fiber
bundle.
Comparative Example 39
Using, as a continuous fiber, a commercially
available acrylonitrile-based carbon fiber (HM-35), there
was repeated the procedure of Example 112 to obtain a
fiber to which a silicon carbide powder had attached, as
well as a fiber to which silicon carbide whiskers had
attached.
Example 118
Using the fiber of Example 112 and an aluminum
matrix, there was prepared a unidirectionally reinforced
FRM. The FRM had a fiber volume fraction (vf) of 50 %
and a flexural strength of 165 kg/mm2 (tne ROM value was
175 kg/mm2).
- 15~ --
Comparative Example 40
Using the fiber to which a silicon carbide
powder had attached/ obtained in Comparative Example 39
and an aluminllm matrix, there was prepared a unidirec-
tinnally reinforced FRM. The FRM had a fiber volumefraction tv) of ~0 % and a Elexural strength of 130
kg/mm2. Therefsre, the strength was considerably low as
compared with the ROM value tl60 kg/mm )~
Example 119
Using the fiber of Example 113 or 114 and~ as a
matrix 7 aluminum containing 5 ~ in total of copper and
n,agnesium, there were prepared two unidirectionally
reinforced FRM's. These FRM's each had a fiber volume
fraction of 50 %. Their flexural strengths were 170
kgJmm when the fiber of Example 113 was used and 165
kg/mm when the fiber of Example 114 was used, and were
scarcely different from the ROM values ~175.0 kg/mm2~.
Comparative Example 41
Using the fibers of Comparative Example 39 and
the matrix of Example 118, there were prepared two FRM's.
The FRM using the fiber to which a silicon carbide powder
had attached, had a fiber volume fraction (Vf) of 60 ~
and a flexural strength of 125 kg/mm2 ~the ROM value was
160 kg/mm ~. The FRM using the fiber to which silicon
carbide whiskers had attached, had a fiber volume frac-
tion ~Vf) of 50 % and a flexural strength of 100 kg/mm2
~the ROM value was 130 kg/mm ). In the both FRM's, the
strengths were considerably low as compared with the ROM
values.
Example 120
The same inorganic fiber as used in Example 87
was unidirectionally arranged on a pure aluminum foil
~specified by JIS 1070) of 0.5 mm in thickness. Thereon
was placed another aluminum foil of same quality and
si~e. The laminate was subjected to hst rolling at 670C
to prepare a composite foil of fiber and alumin~m. The
~0~
- 155 -
composite foil was piled up in ,a total sheet number of
27, was allowed to stand for 10 minutes at 670C under
vacuum, and then subjected to h~t pressing at 6~0C to
obtain an inor~anic fiber-reinforced aluminum composite
material.
The inorganic fiber was measured for initial
deterioration rate ~kg~mm2.sec 1) and fiber strength
reduction (%). The composite material was measured for
tensile strength in fiber direction (kg/mM2), tensile
1~ modulus of elasticity in fiber direction ~t~n2),
interlaminar shear strength ~kg~mm2), tensile strength in
direction perpendicular to fiber (kg/mm2) and fatigue
limit/tensile strength. The results are shown in Table
14. The Vf of the composite material was 30 ~ by volumeO
Comparative Example 42
A carbon fiber-reinforced aluminum composite
material was prepared in the same manner as in Example
120 except that there was used, in place of the inorganic
fiber used in the present invention, a commercially
available PAN-based carbon fiber having a tensile
strength of 300 kg~mm2 and a modulus of elasticity of 21
t/mm2. The carbon fiber and the composite material were
measured for the above mentioned properties. The results
are shown in Table 14. The Vf of the composite material
was 30 % by volume.
- 156 -
Table 14
Comparative
Example 1~ E~
Initial det~riora~ion
rate ~kg~mm ~sec ) 0.9 3.2
Eiber strength
reduction (%) 55 90
Tensile strength in 2
fiber direction (kg/mm ) 51 25
Tensile modu:Lus of
elasticity in f~ber
direction (t/mm ) 908 6.5
Interlaminar sh~ar
strength ~kg/mm ~ 4.~ 2.2
Tensile strength in
direction perpe~dicular
to fiber (kg/mm ) 3.9 1.8
Fatigue limit~
tensile strength 0.38 0.25
Example 121
A fiber-reinforced metal was prepared in the
same manner as in Example 120 except that there was used
an aluminum alloy foil ~specified by JIS 6061). The
inorganic fiber and the fiber-reinforced metal were
measured for the above mentioned properties. The results
are shown in Table 15.
C0mparative Example 43
A carbon fiber-reinforced aluminum composite
material was prepared in the same manner as in Example
121 except that the inorganic fiber was replaced by a
carbon fiber. The carbon fiber and the composite mate-
rial were measured for the above mentioned properties.
The results are shown in Table 15.
- 157 -
Table 15
Comparative
Example 121 Example 43
Initial det~riora~ion
rate (kg~mm .sec ) 1.1 3.9
Fiber strength
reduction ~%) 59 95
Interlaminar sh~ar
strength tkg~mm ) 10.1 4.0
Tensile strength in
direction perpe~dicular
to fiber ~kgJmm ) 7.5 3.2
Fatigue limit~
tensile strength 0.39 OD25
Example 122
A plurality of the inorganic fibers I were
arranged unidirectionally and coated with metallic
titanium in a thickness of 0.1-10 ~ by the use of a
thermal spraying apparatus. This coated inorganic fiber
layer was piled up in a plurality of layers with a
titanium powder being packed between each two neiyhboring
layers. The laminate was press molded. The molded
material was prefired for 3 hours at 520C in a hydrogen
atmosphere and then hot pressed at 200 kg~cm2 at 1150C
for ~ hours in an argon atmosphere to obtain an inorganic
fiber-reinforced titanium composite material~
The inorganic fiber was measured for initial
deterioration rate (kg/mm2.sec 1) and fiber strength
reduction ~%), and the composite material was measured
for tensile strength in fiber direction (kg/mm2),
interlaminar shear strength (kg/mm2), tensile strength in
direction perpendicular to fiber ~kg~mm2) and fatigue
limit/tensile strength. The results are shown in Table
16.
- 158 -
The tensile strength in fiber direction~ of the
composite materiaL was 122 kg/mm , which was about t~o
times the tensile strength of metallic titanium alone.
The Vf of the composite materiaL was 45 % by volume.
Comparati~e Example 4~
A carbon fiber reinforced titanium composite
material was prepared in the ~ame manner as in Example
122 except that the inorganic fiber was replaced by a
carbon fiber. The carbon fiber and the composite mate-
rial were measured for the above mentioned properties~
The results are shown in Table 16.
Table 16
Comparative
Exam~le 122 Example 44
Initial det~riora~ion
rate (kyJmm .sec ) 1.0 3.7
Fiber strength
reduction (%) 58 95
Tensile strength in
fiber direction (kg/mm2) 122 52
Interlaminar sh~ar
strength (kg/mm ) 12.1 4.7
Tensile strength in
direction perpe~dicular
to fiber (kg~mm ) 8.3 3O8
Fatigue limit/
tensile strength 0.33 0.20
Example 123
A plurality of the inorganic fibers I were
arranged unidirectionally and coated with a titanium
alloy (Ti~6Al-4V) in a thickness of 0.1-10 ~ by the use
of a thermal spraying apparatus. This coated inorganic
fiber layer was piled up in a plurality of layers with a
titanium powder being packed between each two neighboring
- 159 -
layers. The laminate was press molded~ The molded
material was prefired for 3 hours at 520C in a hydrogen
gas atmosphere and then hot prer,sed at 200 kg/cm2 at
1150C for 3 hours in an argon atmosphere to obtain an
inorganic fiber-reinforced titanium composite material.
The inorganic fiber was measured for initial
deterioration rate ~kg/mm2.sec 1) and fiber strength
reduction ~%), and the composite material was measured
for interlaminar shear strerlgth tkg/mm23, tensile
strength in direction perpendicular to fiber (kg/mm2) and
fatigue limit/tensile strength. The Vf of the composite
material was 45 ~ by volume. The results are shown in
Table 17.
Comparative Example 45
A carbon fiber-reinforced titanium composite
material was prepared in the same manner as in Example
123 except that the inorganic fiber was replaced by a
carbon fiber. The carbon fiber and the composite mate-
rial were measured for the above mentioned properties.
The results are shown in Table 17.
Table 17
Comparative
Example 123 Example 45
Initial det~riora~ion
rate (kg/mm .sec ) 1.1 4.0
Fiber strength
reduction (%) 61 96
Interlaminar sh~ar
strength (kg/mm ) 16.9 7O4
Tensile strength in
direction perpe~dicular
to fiber lkg~mm ) 13.5 6.0
Fatigue limit/
tensile strength 0.32 0.19
~f~
- 160 -
Example 124
On a pure magnesium foil of 0.5 mm in thickness
were unidirectionally arranged a plurality of the in-
organic fibers I. Thereon was placed another magnesium
foil of same quality and size. The laminate was hot
rolled at 670~C to obtain a composite foil of fiber and
magnesium. This composite foil was piled up in a total
number of 27~ wa~ allowed to stand for 10 minutes at
670C under vacuum, and then was hot pressed at 600C to
obtain an inorganic fiber-reinforced magnesium composite
materialO
The inorganic fiber was measured for initial
deterioration rate (kg~mm2.sec 1) and fiber strength
reduction (%~, and the composite material was measured
for interlaminar shear strength ~kg/mm2), tensile
strength in direction perpendicular to fiber (kg~mm2) and
fatigue limit/tensile strength. The Vf of the composite
material was 30 % by volume. The results are shown in
Table 18.
Comparative Example 46
A carbon fiber-reinforced magnesium composite
material was prepared in the same manner as in Example
124 except that the inorganic fiber was replaced by a
carbon fiber. The carbon fiber and the composite mate-
rial were measured for the above mentioned properties.The results are shown in Table 180
.7
~ 161 -
rrable 18
Comparative
3~xample 12~ Example 46
Initial det~riora~ion
rate ~kg/mm .sec ) lol 4~1
Fiber strength
reduction (%) 64 96
Interlaminar sh~ar
strength ~kg/mm ~ 4.1 1.5
Tensile strength in
direction perpe~dicular
to Eiber (kgJmm 1 3.1 1.3
Fatigue limit~
tensile strength 0.34 0~21
Example 125
A plurality of the inorganic fibers I were
undirectionally arranged on a magnesium alloy foil
(specified by JIS A 891) of 0.5 mm in thickness. Thereon
was placed another magnesium alloy foil of same quality
and size. The laminate was not rolled at 670~C to pre-
pare a composite foil of fiber and magnesium alloy. This
composite foil was piled up in a total number of 27, was
allowed to stand for 10 minutes at 670C under vacuum,
and was hot pressed at 6C0C to obtain an inorganic
fiber~reinforced magnesium composite material.
The inorganic fiber was measured for initial
deterioration rate (kg~mm2.sec 1) and fiber strength
reduction (%), and the composite material was measured
for interlaminar shear strength (kgJmm2~, tensile
strength in direction perpendicular to fiber (kgJmm2) and
fatigue limit/tensile strength. The Vf of the composite
material was 30 % by volume. The results are shown in
Table 19.
Comparative Example 47
A carbon fiber-reinforced magnesium composite
r5
~ 1~2 -
material was obtained in the ~ame manner as in Example
125 except that the inorganic fiber was replaced by a
carbon f iber . The carbon fiber and the composite mate-
rial were ~easured for the above mentioned properties.
The results are shown in Table 19.
Table 19
Comparative
xam~le 125 Example 47
Initial det~riora~ion
rate (kg/mm ~sec ~ 1.0 4.0
Eiber strength
reduction (~ 62 96
Interlaminar sh~ar
strength ~kg/mm ) 6.8 2~8
~ensile strength in
direction perpe~dicular
to fiber (kg/mm ) 5.2 2.2
Fatigue limit~
tensile strength 0.36 0.27
Example 126
An inorganic fiber~reinforced aluminum com-
posite material was prepared in the same manner as inExample 120 except that there was used the inorganic
fiber II. The composite material had a Vf of 30 % by
volume.
The tensile strength of the composite material
was about the same as that of the composite material
obtained in Example 120, but the tensile modulus of
elasticity was 15.2 t/mm-.
Comparative Example 48
A carbon fiber reinforced aluminum composite
material was prepared in the same manner as in Example
120 except that there was used the silicon carbide fiber
obtained in ComparatiYe Example 27 (1).
t,~
- 163 -
The tensile strength of the composite material
was about the same as that of the composite material
obtained in Example 120, but the tensile modulus of
elasticity was 6.3 t~mm2O The Vf of the composite
material was 30 ~ by volume~
Example 127
(1) 500 g of the same FCC slurry oil as obtained in
Reference Example 2 was heated for 1 hour at 450C in a
nitrogen gas current of 1 liter/min to distil off the
450C fraction. The residue was filtered at 200C to
remove the portion which was not in a molten state at
200C, and thereby to obtain 225 g of a reforming removed
pitch~
The reforming pitch had a xylene insoluble
content of 75 ~ and was optically isotropic.
(2) 400 9 of the FCC slurry oil was heated at 450C
in a nitrogen gas current to remove the 450C fraction.
The residue was filtered at 200C to remove the portion
which was not in a molten state at 200C, and thereby to
obtain 180 g of a reforming pitch. 180 g of the re-
forming pitch was subjected to a condensation reaction
for 7 hours at 400C in a nitrogen current while removing
the light fractions formed by the reaction, to obtain 85
g of a heat-treated pitch.
This heat-treated pitch had a melting point of
268C, a xylene insoluble content of 92 % and a quinoline
insoluble content of 12 %. The pitch was a mesophase
pitch having an optical anisotropy of 89 % when the
polished surface was observed by a polarizing microscope~
The pitch is hereinafter referred to as the mesophase
pitch (A).
The FCC slurry oil was heated at 420C in a
nitrogen gas current to distil off the 420C fraction.
The residue was subjected to a polycondensation reaction
for 5 hours at 400C to obtain a mesophase pitch having a
melting point of 258C, a xylene insoluble content of
~ 9~
- 16~1 -
65 %, a quinoline insoluble content of 6 % and an optical
anisotropy oE 52 %. The p1tch is hereinafter referred to
as the mesophase pitch (B)o
(3) 49 g oE the pitch obtained in (1) above was
mixed with 21 g of the organosilicon polyme~ obtained in
Reference Example 1 and 20 ml of xylene. The mixture was
heated with stirring to distil o$f xylenei and the re-
sidue was reacted for 6 hours at 40n~c to obtain 39 g of
a precursor reaction product.
Infrared absorption spectrum analysis indicated
that in the precursor reaction product there occurred the
decrease of the Si-H bond (IR: 2100 cm 1) present in
organosilicon polymer and the new formation of Si-C (this
C is a carbon of benzene ring) bond (IR~ 1135 cm 1).
Therefore, it became clear that the precursor reaction
product contained a structure in which part of the
silicon atoms of organosilicon polymer bonded directly
with carbons o the polycyclic aromatic ring.
39 g of the precursor reaction product was
mixed ~ith 11 g of a xylene solution containing 2.75 g
(11 %) of tetraoctoxytitanium ~Ti(OC8H17)~]. The mixture
was heated to distil off xylene. The residue was reacted
for 2 hours at 340C to obtain 38 g of a reaction pro-
duct.
The reaction product contained no xylene in-
soluble, had a weight-average molecular weiyht of 1650
and a melting point of 272C~
(4) 35 g of the above reaction product and 70 g of
the mesophase pitch (A~ were melt mixed for 1 hour at
310C in a nitrogen atmosphere to obtain a uniform
titanium-containing reaction product. The product had a
melting point of 272C and a xylene insoluble content of
59 %.
(5) The titanium-containing reaction product was
used as a spinning material and subjected to melt spin-
ning at 340C using a metallic nozzle of 0.~5 mm in
1~0 ~ J3 ~
- 165 -
diameter. The spun fiber was subjected to curing in air
and then to pyrolyzing of 1300C in an argon atmosphere
to obtain an inorganic fiber of 10 ~m in diameter.
The inorganic fiber had a tensile strenyth of
320 kg/mm2 and a tensile modulus of elasticity oE 32
t/mm2. The fiber, when the breaking surface was observed
by a scanning type electron microscopei had a coral~like
random-radial mixed structure consisting of a plurality
of piled crystal layers~
The inorganic fiber, when heated (oxidized) in
air, showed substantially no weight decrease up to 700C
and showed only 7 % of weight loss at 800~C.
Example 128
39 g of the precursor reaction product obtained
in Example 127 t3) was mixed with an ethanol-xylene
solution containing 5.4 g (1.5 ~ of tetrakisacetyl-
acetonato~irconium. After xylene was distilled off, the
residue was polymerized for 1 hour at 250C to obtain
39.5 g of a reaction product.
20 g of the above reaction product and 50 g of
the mesophase pitch (A) prepared in the same manner as in
Example 127, were mixed in a fine particle state. The
mixture was melted in a spinning chimney at 350~C and
spun at 340C using a nozzle of 0.2 mm in diameter. The
spun fiber was cured at 250~C in air and then pyrolyzed
at 1400~C in an argon atmosphere to obtain an inorganic
fiber of 11 ~ in diameter.
The fiber had a tensile strength of 325 kg/mm2
and a tensile modulus of elasticity of 35 t/mm2.
Example 129
57 g of a precursor reaction product was ob-
tained in the same manner as in Example 127 except that
the amounts of the reforming pitch and organosilicon
polymer used were changed to 60 g and 40 g, respectively.
40 g of the precursor reaction product was
mixed with an ethanol-xylene solution containing 7.2 g
- 166 -
(1.5 ~) of hafnium chloride. Af-ter xylene was distilled
off, the residue was polymerized for 1 hour at 250~C to
obtairl 43~5 g of a reaction product.
20 g of the reaction product and 80 g of the
mesophase pitch ~A) were mixed in a fine particle state.
The mix-t-lre was melted and deaerated at 350UC in a
spinning chimney, was melt spun at 350C9 was cured at
270C, and was pyrolyzed at 1200C in argon to obtain an
inorganic fiber of 12 5 ~. The fiber had a tensile
strength of 315 kg/mm and a tensile modulus of
elasticity of 35 t/mm2.
Example 130
18 gO of the reaction product obtained in the
same manner as in Example 127 (3) and 90 g 3f the meso-
phase pitch (B) described in Example 127 (2~ were meltmixed for 1.5 hours at 300C in a nitrogen current to
obtain a spinning dope having a melting point of 265C
and a xylene insQluble content of 49 %. The dope was
melt spun at 330C using a nozzle of 0.15 mm in diameter,
was cured at 3D0C, and was pyrolyzed at 1700C to obtain
an inorganic fiber of 8 ~ in diameter. The fiber had a
tensile strength of 305 kg/mm and a tensile modulus of
elasticity of 38 t/mm .
Example 131
39 9 of the precursor reaction product obtained
in Example 127 (3) was mixed with 0.9 g o tetrabutoxy-
titanium. The mixture was subjected to the same pro-
cedure as in Example 127 to obtain 38.5 g of a reaction
product. 18 9 of this reaction product and 90 g of the
mesophase pitch (A) described in Example 127 (2) were
melt spun at 345C in the same manner as in Example 128,
was cured at 300C, and pyrolyzed at 2100C in an argon
atmosphere.
The resulting inorganic fiber had a diameter of
7.5 ~(, a tensile strength of 290 kgfmm2 and a tensile
modulus of elasticity of 45 t/mm2~
- 167 -
Example 132
An inorganic fiber was obtained i.n the same
manner as in Example 131 except that the amount of
tetrabutoxytitanium used was 9 0 g and the p~rolyzing
temperature was 2500C.
The inorganic fiber had a diameter of 7.5 , a
tensile strength of 335 kg/mm and a tensile modulus of
elasticity of 55 t/mm .
Example 133
There were uniformly mixed 100 parts of a
bisphenol A type epoxy resin (XB2879A manufactured by
Ciba Geigy Co.3 and 20 parts of a dicyandiamide curing
aqent (XB2879B manufactured by Ciba Geigy Co.). The
mixture was dissolved in a 1:1 tby weight) mixed solvent
f methyl cellosolve and acetone to prepare a solution
containing 28 % of the mixture.
The inorganic fibers obtained in Examples
127-130 were impregnated with the above solution, were
unidirectionally taken off using a drum winder, and were
heated for 14 minutes at 100C in a heat circulation oven
to prepare half-cured inorganic fiber prepregs in which
the fibers were arranged unidirectionally. These pre-
pregs had a fiber content of 60 % by volume and a thick-
ness of 0.2 mm.
Each prepreg was piled up in a total number of
10 and press molded at 11 kg/cm2 at 130C for 90 minutes
to obtain four kinds of unidirectionally reinforced epoxy
resin composite materials of 250 mm x 250 mm.
A test sample of 12~7 mm (width), 85 mm (length)
and 2 mm (thickness) for measurement of flexural strength
was prepared from each of the above composite materials,
by cutting. Ea~h test sample was subjected to a three-
point bending test (span/width = 32, speed ~ 2 mm/min).
The flexural strengths of each composite material at 0
and 90 directions are shown in Table 2G.
- 1~8 --
Separately, a composite material was prepared
in the same manner as above except that there ~as used a
pitch-based carbon fiber havin~ a tensile strength of 280
ky/mm2 and a tensile modulus of elasticity of 55 t/mm2.
The flexural stengths of this composite material are also
shown in Table 20.
Table 20
~lexural strengths (kg/mm2)
Fiber 0 90
_
Example 127 203 13~0
Example 123 205 13.2
Example 129 201 13.8
Example 130 198 12.0
Carbon fiber 100 3~5
Example 134
(1) 57 g of the pitch containing 25 ~ of a xylene
insoluble portion, obtained in Example 10 tl) was mixed
with 25 g of the organosilicon polymer obtained in Refer-
ence Example 1 and 20 ml of xylene. The mixture was
heated with stirring to distil off xylene, and the re-
sidue was reacted for 4 hours at 400C to obtain 57.4 gof a precursor reaction product.
Infrared absorption spectrum analysis indicated
that in the precursor reaction product there occurred the
decrease of the Si-H bond (IR: 2100 cm 1) present in
organosilicon polymer and the new formation of Si-C (this
C is a carbon of benzene ring) bond tIR: 1135 cm 1).
Therefore, it became clear that the precursor reaction
product contained a polymer having a portion in which
part of the silicon atoms of organosilicon polymer bonded
directly with carbons of the polycyclic aromatic ring.
- 169 -
57.4 9 or the precursor reaction product was
mixed with 15~5 g vf a xylene solution containing 3O87 g
(25 ~) of tetraoctoxytitanium ~Ti (OC8H17)4]. AEter
xylene was distilled oEf~ ~he r,esidue was reacted for 1
hour at 340C tv obtain 56 g of a reaction product.
The reaction product contained no xylene in-
soluble portion/ had a weight-aJerage molecular weight of
1580, a melting point of 258C and a softening point of
2~2C~
~2) 6.4 g of the above reaction product and 90 g of
the sarne mesophase pitch as obtained in Example 10 (2)
were mixed~ The mixture was melted or 1 hour at 380C
in a nitrogen atmosphere to obtain a uniform titanium-
containing reaction product.
The reaction product had a melting point of
264C, a softening point of 307C and a xylene insoluble
content of 68 %.
~3) The above reaction product was used as a spin-
ning material and melt spun at 360C using a metallic
nozzle of 0.15 mm in diameter. The spun fiber was sub-
jected to curing at 300C in air and then to pyrolyzing
at 1300~C in an argon atmosphere to obtain an inorganic
fiber of 7D5 m in diameter.
The fiber had a tensile strength of 358 kg~mm
25 and a tensile modulus of elasticity of 32 t/mm2O The
fiber, when the breaking surface was observed by a scan-
ning type electron microscope, had a coral-like random-
radial mixed structure consisting of a plurality of piled
crystal layers.
The inorganic fiber was ground, subjected to
alkali fusion, and treated with hydrochloric acid to
convert into an aqueous solution. The solution was
subjected to high frequency plasma emission sp34tro-
chemical analysis (ICP). As a result, the invrganic
fiber contained silicon and titanium in amounts of 0.95 %
and 0.06 %, respectively.
- 170 -
The above fiber~ when heated and oxidized in
air; showed no reduction in above mentioned mechanical
properties evell at 6G0C and W21S superior in oxidation
resistance to commercially available carbon fibers which
were oxidized and burnt out at 600C~
E`xample 135
39 g of the precursor reaction product obtained
in Example 134 was mixed with an ethanol-xylene solution
containing 5.4 g (105 %) of tetrakisacetylacetonato-
zirconium~ After xylene was distilled off~ the residuewas polymerized at 250C for 1 hour to obtain 39O5 g of a
reaction product.
20 g of the reaction product and 50 g of the
same mesophase pitch as used in Example 134 (1) were
finely ground and melt mixed for 1 hour at 360C. The
melt was spun at 350C using a no~zle of 0.2 mm in dia-
meter. The spun fiber was cured at 250C in air and then
pyrolyzed at 1400C in an argon atmosphere to obtain an
inorganic fiber of 11 in diameter.
The fiber had a tensile strength of 345 kg/mm2
and a tensile modulus of elasticity of 35 t/mm2.
Example 136
57 g of a precursor reaction product was ob-
tained in the same manner as in Example 134 except that
the amounts of the reforming pitch and organosilicon
polymer used were changed to 50 g and 40 g~ respectively.
40 g of the precursor reaction product was
mixed with an ethanol-xylene solution containing 7.2 g
(1.5 %~ of hafnium chloride. After xylene was distilled
off, the residue was polymerized for 1 hour at 250C to
obtain ~3.5 9 of a reaction product.
20 g of the reaction product and 80 g of the
same mesophase pitch as used in Example 134 (2) were
finely ground and melt mixed for 1 hour at 350C. The
melt was spun at 350C. The spun Eiber was cured
at 270C and pyrolyzed at 1200C in argon to obtain an
- 171 -
inorgarlic fiber of 12A5 ~ The Eiber had a tensile
strength of 335 kg/mm2 and a tensile modulus of
elasticity of 35 k/mm
Example 13 '7
108 g of the same reaction product as obtained
in Example 134 (1) and 90 g of the mesophase pitch ~B)
obtained in Example 127 (2) were melt mixed for 1.5 hours
at 400~C in a nitrogen current to obtain a spinning dope
havillg a melting poin~ of 265C and a ~ylene insoluble
10 COntent O~ 55 %. The dope was melt spun at 350C using a
a nozzle of 0.15 mm in diameterO The spun fiber was
cured at 300C and then pyrolyzed at 1700C to ohtain an
inorganic fiber of 8 ~ in diameter~
The inorganic fiber was ground, subjected to
15 alkali fusion and treated with hydrochloric acid to
convert into an aqueous solution~ The aqueous solution
was subjected to high frequency plasma emission spectro-
chemical analysis (ICP). As a result, the inorganic
fiber contained silicon and titanium in amounts of 0.3
and 0.015 ~ ~ respectively.
The fiber had a tensile strength of 335 kg/mm
and a tensile modulus of elasticity of 40 t~mm2.
Example 138
39 g of the precursor reaction product obtained
25 in Example 134 was mixed with 0.9 g of tetrabutoxy-
titanium, and the procedure of Example 134 (1) was
repeated to obtain 38.5 g of a reaction product~
18 9 of this reaction product and 90 g of the
same mesophase pitch as obtained in Example 10 (2) were
melt spun at 355C in the same manner as in Example 131.
The spun fiber was cured at 300C and then pyrolyzed at
2100C in an argon atmosphere.
The resulting inorganic fiber had a diameter of
of 7.5~, a tensile strength of 290 kg/mm2 and a tensile
modulus of elasticity of 45 t/mm2.
- 172
Example 139
An inorganic fiber was obtained in the same
manner as in Example 138 except that the amount of
tetrabutoxytitanium used was changed to 9 g and the
pyroly~ing temperature was changed to 2500C.
The inorganic fiber had a diameter of 7.5~, a
tensile strength of 335 kg/~m2 and a tensile modulus of
elasticity of 59 t/mm2.
Example 140
The inorganic fibers obtained in Examples
134-137 were used as a reinforcing agent to obtain uni-
directionally reinforced epoxy resin (bisphenol A type3
composite materials (Vf: 60 ~ by volume~. The flexural
strengths of these composite materials are shown in Table
21.
Table 21
F ural strengths Ikg/mm )
Inorganic fiber 0 90
Example 134 24813.0
Example 135 24013.2
Example 136 23813.8
Example 137 23512.0
Example 141
(1) 700 g of the FCC slurry oil obtained in
Reference Example 2 was heated to 450C in a nitrogen gas
current to distil off the 450C fraction. The residue
was filtered at 200C to remove the portion which was not
in a molten state at 200C, and thereby to obtain 200 g
of a reforming pitch.
The reforminy pitch contained a xylene in-
soluble portion in an amount of 25 ~ and was optically
isctropicO
5~
- 173 -
57 g of the reforming pitch was mixed with 25 y
of the organosilicon polymer obtained in ~eference
Example 1 and 20 ml of xyleneO The mixture was heated
with stirring to distil off xy]ene. The reisdue was
reacted for 4 hours at 400C to obtain 57~4 g of a pre-
; cursor reacticn product~
Infrared absorption spectrum analysis indicated
that in the precursor reaction product there occurred the
decrease of the Si-H bond (IR: 2100 cm 1) present in
organosilicon polymer and the new formation of Si-C (this
C is a carbon of benzene ring) bond (IR: 1135 cm 1)
Therefore, it became clear that the precursor reaction
product contained a portion in which part of the
silicon atoms of organosilicon polymer bonded directly
with carbons of the polycyclic aromatic ring.
57.4 g of the precursor reaction product was
mixed with 1505 g of a xylene solution containing 3.87 g
(25 ~ of tetraoctoxytitanium [Ti5OC8H17)4]. After
xylene was dis~illed off, the residue was reacted for l
hour at 340C to obtain 56 g of a reaction product.
The reaction product contained no xylene in-
soluble portion and had a weight-average molecular weight
of 1580, a melting point of 258C and a softening point of
292C.
180 g of the above reforming pitch was sub-
jected to a polycondensation reaction for 8 hours at
400C while removing the light fractions generated by the
reaction, to obtain 97.2 g of a heat-treated pitch.
The heat-treated pitch had a melting point of
263C, a softening point of 308C, a xylene insoluble
content of 77 % and a quinoline insoluble content of
31 %. The pitch, when the polished surface was observed
by a polarizing microscope, was a mesophase pitch having
an optical anisotropy of 75 %.
6.4 g of the reaction product and 90 % of the
mesophase pitch were melt mixed for l hour at 380C in a
- 17~ -
nitrogen atmosphere to obtain a uniform ti~anium-contain-
lng reaction product.
The reaction product had a melting point of
264C, a softening point of 307"C and a xylene insoluble
content of 68 %~
The reaction product was used as a spinning
material and melt spun at 360C using a metallic nozzle
of 0.15 mm in diameter. The spun fiber was cured at
300C in air and then pyrolyzed at 1300C in an argon
atmosphere to obtain an inorganic fiber IV of 7.5 ~ in
diameter.
The inorganic fiber had a tensile strength of
358 kg/mm2 and a tensile modulus of elasticity of 32
t/mm . The fiber, when the breaking surface was observed
by a scanning type electron microscope, had a coral-like
random-radial mixed structure consisting of a plurality
of piled crystal layersO
The inorganic fiber was ground, subjected to
alkali fusion, treated with hydrochloric acid, and con-
2~ verted to an aqueous solution. The aqueous solution wassubjected to high frequency plasma emission spectro~
chemical analysis (ICP). As a result, the inorganic
fiber contained silicon and titanium in amounts of 0.95
and 0.06 %, respectively.
(2) 100 parts of a bisphenol A type epoxy resin
(XB2879A manufactured by Ciba Geigy Co.) and 20 parts of
a dicyandiamide curing agent (XB2879B manufactured by
Ciba Geigy Co.) were mixed uniformly. The mixture was
dissolved in a 1~1 (by weight~ mixed solvent of methyl
cellosolve and acetone to obtain a solution containing
28 % of the mixture.
The inorganic fiber IV obtained in (1) above
was impregnated with the above solution, was taken off
unidirectionally using a drum winder, and was heated for
14 minutes at 100C in a heat circulation oven to prepare
a half-cured inorganic fiber prepreg wherein the fiber had
- ~75 -
been arranged unidirectionally~ The prepreg had a Eiber
content of 60 ~ by volume and a thickness of O.lS mm.
The prepreg was piled up in a total number of
10 with the fibers of all the prepregs arrangecl in the
same direction and press molded at 7 kg/cm2 for 4 hours
at 17UC to obtain a unidirectionally reinforced epoxy
resin composte material of 250 mm x 2$0 mm.
From the composite material was cut out a test
sample of 12.7 mm (width), 85 mm (length) and 2 mm
(thickness) for flexural strength measurement. Using the
test sample~ a three-point bending test (span/width = 32
mm) was effected at a speed of 2 mm/min. The mechanical
properties of the composite material are shown below.
Tensile strength tkg/mm2)192
Tensile modulus ~f
elasticity (t/mm ) 19
Flexural strenqth ~kg~mm ) 152
Flexural modulus of
elasticity (t/mm2) 18
Tensile strength in direction2
perpendicular to fiber (kg/mm ) 6.9
Tensile modulus of elasticity
in direction p~rpendicular
to fiber tt/mm ~ 5.5
Flexural strength in directio~
perpendicular to fiber (kg/mm ) lQ.2
Flexural modulus of elasticity
in direction p~rpendicular
to fiber (t/mm ) 5.4
Interl~minar shear strength
(kg/mm ~ 9.3
Flexural shock (kg.cm/mm2) 272
,5~
- 176 -
Example 142
(1) 39 g of the same precursor reaction product as
used in Example 141 (1~ was mixed with an ethanol-xylene
solution containing 5 4 g ~1.5 %) of tetrakisacetyl-
acetonatozirconium. After xylene and ethanol were dis-
tilled off~ the residue was polymerized Eor 1 hour at
250C to obtain 39.5 y of a reaction product.
2G g of the reaction product and 50 g of the
same mesophase pitch as used in Example 141 (1) were
finely ground and then melt mixed for 1 hour at 360~C~
The mixture was melt spun at 350C using a nozzle of 0.2
mm in diameter. The spun fiber was cured at 250C in air
and then pyrolyzed at 1400C in an argon atmosphere to
obtain a zirconium-containing inorganic fiber V of 11
5 in diameter.
The inorganic fiber had a tensile strength of
345 kg/mm2 and a tensile modulus of elasticity of 35
t/mm2 .
(2) There was used, as a reinforcing fiber, the
inorganic fiber V obtained in (1) above; as a matrix,
there was used a commercially available unsaturated
polyester resin in place of the epoxy resin; and the
procedure of Example 141 was repeated to prepare an
inorganic fiber-reinforced polyester composite material
having a fiber content of 60 % by volume. The mechanical
properties of the composite material are shown below.
Tensile strength (kg/mm2)180
Tensile modulus 2f
elasticity (t/mm ) 19
Flexural strength (kg/mm2) 240
Flexural modulus2of
elasticity ~t~mm ) 18
Tensile strength in direction
perpendicular to fiber (kg/mm2) 6.5
- 177 -
Tensile ~odulus of elasticity
in direction p~rpendicular
to fiber (t/mm ) 5.5
Flexural strength in directio~
perpendicular to Eiber (kg/~m ~ 9.7
Flexural modulus of e:Lasticity
in direction p~rpendicular
to fiber (t/mm ) 5.5
Interl~minar shear strength
(kg/mm ) 9.0
Flexural shock (kg.cm/mm2) 264
Example 143
Sl) 57 g of a precursor reaction product was ob-
tained in the same manner as in Example 141 ~1) except
that the amounts of the reformin~ pitch and organosilicon
polymer used were changed to 60 g and 40 g, respectively.
40 g of the precursor reaction product was
mixed with an ethanol-xylene solution containing 7.2 g
(1.5 %) of hafnium chloride. After xylene and ethanol
were distilled off, the residue was polymeriæed for 1
hour at 250C to obtain 43.5 g of a reaction product.
20 g of the reaction product and 80 9 of the
same mesophase pitch as used in Example 141 (1) were
finely ground and then melt mixed for 1 hour at 360C.
15 The mixture was melt spun at 350C using a nozzle of 0~2
mm in diameter. The spun fiber was cured at 270C in air
and pyrolyzed at 1200C in an argon atmosphere to obtain
a hafnium-containing inorganic fiber VI of 12.5 ~ in
diameter.
The inorganic fiber had a tensile strength of
335 kg~mm2 and a tensile modulus of elasticity of 35
t~mm2 .
(2) The procedure of Example 141 was repeated
except that there was used, as a reinforcing fiber, the
inorganic fiber VI obtained in (1) above and, as a
matrix~ there was used a polyimide resin manufactured by
- 17~
Ube Industries, Ltd. in place of ~he epoxy resin, to
prepare an inorganic fiber-reinforced polyimide composite
material having a fiber content: of 60 % by volume.
The mechanical properties of the composite
material are shown below.
Tensile strength (kg~'mm2) 177
Tensile modulus ~f
elasticity ~t/mm ~ 19
Flexural strength (kg/mm ) 239
Flexural modulus of
elasticity lt/mm21 18u5
Tensile strength in direction2
perpendicular to fiber ~kg/~n ) 6~4
Tensile modulus of elasticity
in direction p~rpendicular
to fiber tt/mm ) 5.4
Flexural strength in directio~
perpendicular to fiber (kg/mm ) 9.6
Flexural modulus of elasticity
in direction p~rpendicular
to fiber (t/mm ) 5~4
Interl~minar shear strength
(kg/mm ) 8.9
Flexural shock (kg.cm/mm2) 261
Example ~44
~1) 1.8 g of the same reaction product as obtained
in Example 141 (1) and 90 9 of a mesophase pitch were
melt mixed for 1.5 hours at 400C in a nitrogen current
to obtain a spinning dope having a melting point of 265C
and a xylene insoluble content of 55 %. The dope was
melt spun at 350~C using a a nozzle of 0.15 mm in dia-
meter. The spun fiber was cured at 300C and then
1~ pyrolyzed at 1700~C to obtain an inorganic fiber VII of
8~ in diameter.
- 179 -
The inorgallic fiber VII ~as ground, subjected
to alkali fusionO treated with hydrochloric acid, and
converted to an aqueous solutiomO The aqueous solution
was subjected to high frequency plasma emission spectro-
chemical analysis (ICP)o ~s a :result, the inorganicfiber VII contained silicon and titanium in amounts of
0O3 % and 0.015 %, respectively.
The fiber had a tensile strength of 335 ky/mm
and a tensile modulus of elasticity of 40 timm2.
(2) The inorganic fiber VII obtained in (1) above
was used as an inorganic fiber and the procedure of
Example 141 was repeatd to obtain an inorganic fiber-
reinforced epoxy composite material having a fiber con-
tent of 60 % by volume.
The mechanical properties of the composite
material are shown below.
Tensile strength (kg/mm )180
Tensile modulus ~f
elasticity (t/mm ) 24
Flexural strength (kg/mm2) 242
Flexural modulus of
elasticity (t/mm2~ 22
Tensile strength in direction2
perpendicular to fiber (kg/mm ) 6.5
Tensile modulus of elasticity
in direction p~rpendicular
to fiber (t/mm ) 6.6
Flexural strength in directio~
perpendicular to fiber (kg/mm ) 9O9
Flexural modulus of elasticity
in direction p~rpendicular
to fiber (t/mm ) 6.4
Interl~minar shear strength
~kg/mm ) 9.0
Flexural shock (kg.cm/mm2) 265
.~0~
- 180 -
Example 145
100 parts of a bisphenol A type epoxy resin
(xs2879A manufactllred by Ciba Geigy Co.1 and 20 parts of
a dicyandlamide curing agent (XB287gB manufactured by
Ciba Geigy Co.) were mixed uniformly. The mixture was
dissolved in a 1:1 (by weight) mixed solvent of methyl
cellosolve and acetone to prepa e a solution containing
28 ~ of the mixture~
The same inorganic fiber IV as used in Example
141 (1) were impregnated with the above solution, was
taken off unidirectionally using a drum winder, and was
heated for 14 minutes at ]00C in a heat circulation oven
to prepare half-cured inorganic fiber prepreg wherein the
fiber had been arranged in the same direction.
~sing a surface-treated carbon fiber ~poly-
acrylonitrile-based, tensile strength = 300 kg/mm2,
tensile modulus of elasticity = 24 t/mm2, fiber diameter
= 7~ ) and~ in the same manner as above, there was pre-
pared a half-cured carbon fiber prepreg sheet wherein the
fiber had been arranged in the same direction.
The inorganic IV fiber prepreg sheet and the
carbon fiber prepreg sheet both obtained above were piled
up by turns with the fibers directed in the same direc-
tion and then hot pressed to prepare a hybrid fiber
(inorganic fiber/carbon fiber)-reinforced epoxy composite
material.
The composite material had a total fiber con-
tent of 60 % by volume (inorganic fiber = 30 % by volume~
carbon fiber = 30 ~ by volume)O
The composite material had a tensile strength
at 0 of 197 kg/mm2, a tensile modulus of elastieity at
0 of 16.8 t/mm2, a flexural strength at 0~ of 199
kg/mm2, a flexural strength at 90 of 8.0 kg/mm2, an
interlaminar shear strength of 9.1 kg/mm2 and a flexural
shock of 235 kg.cm/cm2.
-~&15
- 181 -
Example 146
A hybrid fiber-reinforced epoxy composite
material was peepared in the same manner as in Example
145 except that the carbon fiber was replaced by the same
Si-Ti-C-O fiber as obtained in Example 91 (1)~ The
composite material had a total fiber content of 60 % by
volume tinorganic fiber = 30 ~ by volumei Si-Ti-C-O fiber
= 30 % by volume). The composite material had a tensile
strength at 0~ of 207 kg/mm2, a tensile modulus of
elasticity at 0 of 15~9 t/mm~, a flexural strength at 0
of 221 kg/mm2, a flexural strength at 90 of 13.1 kg/mm2,
an interlaminar shear strength of 2.9 kg/mm2 and a
flexural shock of 290 kg.cm/cm .
Examples 147-149
Hybrid fiber-reinforced epoxy resin composite
materials were prepared in the same manner as in Example
145 except that the carbon fiber was replaced by an
alumina fiber, a silicon carbide fiber or a glass fiber
each having the properties shown in Table 7 given pre-
viously (these fibers are referred to as second fiber for
reinforcement). These composite materials had a total
fiber content of 60 % by volume (inorganic fiber = 30 %
by volume, second fiber for reinforcement = 30 % by
volume) .
The properties of the above hybrid fiber-rein-
forced epoxy resin composite materials are shown in Table
22.
- 1~2 -
Table 22
, . ,
\ ~ ~ample 147 EX ~ le 1~8 ~ample 149
\ Second fiber ~ _ _ _ _
\ for rei~orcement .~umina S.ilicon E-glass
\ fiber carbide f iber
M~hanical properti ~ \ -Eiber
. . _ .
Tensile stre~th ~kgJmm ) 166 198 162
__ _ __ ._
Tensile modulus ~f
elasticit~ (t/mm) 16 15 11
_ _ . _
Flexural stre~th tkg/mm2) 192 218 181
Flexural m~lus2of
elasticity ~tJmm ) 14 13 11
.
Compression strength ~kg/mm2l 190 196 169
Example 150
As an inorganic fiber, there was used the
lnorganic fiber V obtained in Example 142 ~1); there was
used, in place of the carbon fiber~ a silicon carbide
riber using carbon as a core and having a diameter of
140 ~, a tensile strength of 350 kg~mm2 and a tensile
modulus of elasticity of 43 t/mm2; and the procedure of
Example 142 was repeated to obtain a hybrid fiber-rein-
forced epoxy resin composite material. The composite
material had a total f.iber content of 46 % by volume
(inorganic fiber = 30 % by volume, silicon carbide fiber
using carbon as a core = 16 ~ by volume). The composite
material had a tensile strength at 0 of 171 kg/mm2~ a
tensile modulus of elasticity at 0 of 22 t/mm2~ a
flexural strenqth at 0 of 218 kg/mm2 and a flexural
strength at 90 of 6.9 kgJmm2
~ 1~3 -
Example 151
There was used~ as an inorganic fiber, the
inorganic fiber VI obtained in Example 143 ~1); there was
used~ in place of the carbon fiber, a boron fiber having
a dîameter of 140 ~, a tensile strength f 357 kg/mm2 and
tensile modulus of elasticity oE 41 t/mm ; and the pro-
cedure of Example 145 was repeated to prepare a hybrid
fiber-reinforcecl epoxy resin composite materlal. The
composite material had a total fiber content of 50 ~ by
volume ~inorganic fiber = 30 ~ by volume, boron fiber =
20 % by volume~
The composite material had a tensile strength
at 0 oE 185 kg/mm2, a tensile modulus of elasticity at
0 of 21 t/mm~, a flexural strength at 0 oE 219 kg/mm
and a flexural strength at 90 of 7.8 kg/mm2
Example 152
There was used, as an inorganic fiber~ the
inorganic fiber VII obtained in Example 144 (1); there
was used, in place of the carbon fiber, an aramid fiber
having a tensile strength of 270 kg/mm2 and a tensile
modulus of elasticity of 13 t/mm2; and the same procedure
as in Example 145 was repeated to prepare a hybrid fiber-
reinforced epoxy resin composite material. The composite
material had a total fiber content of 50 % by volume
(inorganic fiber = 30 ~ by volume, aramid fiber = 30 % by
volume).
The composite material had a tensile strength,
a tensile modulus of elasticity and a flexural strength
all at 0 of 162 kg/mm2, 16 t~mm2 and 166 kg/mm2,
respectively, and was significantly superior in strengths
and modulus of elasticity as compared with an aramid
fiber-reinforced epoxy resin (the aramid fiber-reinforced
epoxy resin having a fiber content of 60 ~ by volume had
a tensile strength, a tensile modulus of elasticity and a
flexural strength all at 0 of 95 kg/mm2, 5.3 t/mm2 and
93 kg/mm , respectively). The composite material had a
J
- 184 -
flexural ~hock of 276 kg~cm/cm2, which was not signifi-
cantl~ lower than the high shock resistance of aramid
f.ibers (the aramid fiber-reinforced epoxy resin having a
fiber content of 60 ~ by volume had a Elexural shock of
302 kg.cm/cm2).
Example 153
To a ~-silicon carbide powder having an average
particle diameter of 0.2~m were added 3 % of a boron
carbide powder and 10 ~ of a polytitanocarbosilane
powder, and they were mixed thoroughlyO The resulting
mixture and a plurality of the inorganic fibers obtained
in Example 127 (53, each having a length of 50 mm and
arranged in the same direction~ were piled up by turns so
that the inorganic fiber content besame 40 ~ by volume.
The laminate was press molded in a mold at 500 kg~cm2.
The molded material was heated to l950~C in an argon
atmosphere at a rate of 200C/h and kept at that tem-
perature for 1 hour to obtain an inorganic fiber-rein-
forced silicn carbide composite sintered material,
EXample 154
An inorganic fiber-rein.forced silicon carbide
composite sintered material was obtained in the same
manner as in Example 153 except that there was used, as
a reinforcing fiber, the inorganic fiber obtained in
Example 132-
The mechanical strengths of the sintered
materials obtained in Examples 153 and 154 are shown in
Table 23. The flexural strength in Table 23 is a value
obtained in a direction normal to fiber. In Table 23,
there are also shown the values of Comparative Examples
27, 28 and 28 ~see Table 10).
- 185 -
<IMG>
3~
- 1~6 --
Example 155
To an ~-silicon nitride powder having an
average particle diameter of 0,5 m s~ere added 2 % of
alumina, 3 % of yttria and 3 % of aluminum nitride~ and
they were mixed thoroughly. The resulting mixed powder
and a plurality of the inorganic fibers obtained in
Example 128, having a length of 50 mm and arranged in the
same direction were piled up by turns so that the fiber
content became about 10 ~ by volume. At ~his time, the
fiber direction of one inorganic fiber layer was dif-
ferent from that of the lower inorganic fiber layer by
90. The resulting laminate was kept at 300 kg/cm2 at
1750C for 30 minutes in a hot pressing machine to obtain
an inorganic fiber-reinforced silicon nitride compvsite
sintered material.
The properties (flexural strength at room
temperature and 1400C, etc.) of the sintered material
are shown in Table 24.
Table 24
Flexural K Flexural Deterioration
streng~h rac~iO stre~th rate 2 -1
(kg~mm ) reduction (kg/mm .sec )
(%) (1200C) (1750C)
Rtoomp. 1400C
_ _
~ample 155 128 80 2.2 0 16
Comparative
xample 30 120 45 _ 55
Example 156
In isopropanol were thoroughly dispersed (a) a
borosilicate glass (7740) powder (a product of Corning
Glass Works) having an average partiole diameter of 44 m
3~
- 187 -
and (h) 45 ~ by volume of chopped fibers obtained by
cutting the inorganic fiber obtained in Example 129 into
a length of 10 mm. The resulting slurry and a plurality
of the same inorganic fibers arranged in the same direc-
tion were piled up by turns~ The laminate was dried andthen treated by a hot pressing machine at 750 kg/mm2 at
1300C for about 10 minutes in an argon atmosphere to
obtain an inorganic fiber-reinforced glass composite
material~
Table 25
Flexural K Flexural Deterioration
streng~h r~io strer,gth rate ~ -1
(kg/mm ~ reduction ~kg/mm .sec )
r ~ ~%) (S00C)(1300~C)
~ample 156 21.0 5.1 2 0.25
.
Comparative
~a~ple 31 14.2 4 1.50
In Table 25, the values of Comparative Example
31 also shown (see Table 12).
Example 157
An alumina powder having an average particle
diameter of 0.5~ m was mixed with 2 % of titanium oxide.
To the resulting mixture was added a spun fiber of a
titanium-containing reaction product lsaid spun ~iber is
a precursor for the inorganic fiber obtained in Example
127 (5)~ so that the fiber content in final mixture
became 15 % by volume. The mixture was stirred thorough-
ly in an alumina ball mill. The average length of the
precursor fiber was about 0.5 mm~ The resulting mixture
was sintered at 2000~C in an argon atmosphere by a hot
pressing machine. The resulting sintered material was
subjected to a spalling test. That is, a plate (40 x 10
~dP O q;~ ! 5 ~1
- 1~8 -
x 3 mm) prepared from the sintered material was rapidly
heated for 20 minutes in a nitrogen atmosphere in an oven
of 1300C~ taken out, and forcibly air-cooled for 20
minutes; this cycle was repeated; thereby, there was
examined a cycle number at which cracks appeared in the
plate for the first time.
The oycle number and mechanical strengths of
tbe sintered material are shown in Table 26.
Table 26
_ _ _ Flexural Spalling
r~tio strength test
reduction
~%~ (~00C)
_
Example 157 3.1 5 9
Comparative
Example 32 _ _
In Table 26, the values of Comparative Example
32 are also shown (see Table 13).
Example 158
A ~-silicon carbide powder having an average
paricle diameter of 0.2~ m was thoroughly mixed with 3 ~
of a boron carbide powder and 10 ~ of a polytitanocarbo-
silane powder. The mixture and a plurality of the in-
organic fibers (obtained in Example 134) having a length
of 50 mm and arranged in the same direction were piled up
by turns so that the fiber content became 40 ~ by volume.
The laminate was press molded at 500 kg/mm2 in a mold.
The resulting molded material was heated to 1950C at a
rate of 200C/h in an argon atmosphere and kept at that
temperature for 1 hour to obtain an inorganic fiber-
reinforced silicon carbide composite sintered material.
- 189 -
Example 159
(1~ 1.8 g of the reaction product of Example 134
(1~ and 9Q g of the same mesophase pitch as obtained in
Example 10 (2) were melt mixed for 1~5 hours at 400~C in
a nitrogen current to obtain a spinning material having a
melting point of 265~C ancl a xylene insoluble cor.tent of
55 %.
The material was melt spun at 350C using a
a nozzle of 0.15 mm in diameter. The spun fiber was
cured at 300~C and then pyrolyzed at 2500~C to obtain
an inorganic fiber of 7 ~ in diameter.
ICP analysis conducted in the same manner as
in Example 134, indicated that the inorganic fiber con-
tained silicon and titanium in amounts o~ 0.3 ~ and
1~ 0.015 %, respectively. The fiber had a tensile strength
of 345 kg/mm2 and a tensile modulus of elasticity of 60
t~mm~.
(2) The same procedure as in Example 158 was re-
peated except that there was used, as a reinforcing
fiber, the inorganic fiber obtained in (1) above, to
obtain an inorganic fiber-reinforced silicon carbide
composite sintered material.
The mechanical strengths of the sintered
materials obtained in Examples 158 and 159 are shown in
Table 27. In Table 27, flexural strength is a value
obtained in a direction normal to fiber.
- 190 -
<IMG>
- 191 -
Example 160
An ~ silicon nitride ]powder having an average
particle diameter of 0.5~ m was thoroughly mixed with 2 %
nf alumina, 3 % of yttria and 3 ~ of aluminum nitride.
The resulting powder and a plurality of the inorganic
fibers of Example 135 having a length of 50 mm and ar-
ranged in the same direction were piled up by turns so
that the fiber content became about 10 % by volume. At
this time, the fiber direction of one inorganic Eiber
layer was different from that of the lower inorganic 2
fiber layer by 90. The laminate was kept at 300 kg/cm
at 1750C for 30 minutes in a hot pressing machine to
obtain an inorganic fiber-reinforced silicon nitride
composite sintered material.
The flexural strength at room temperature and
14000C, etc. of the sintered material are shown in Table
28~
Table ~8
_
Flexural Kl Flexur~ Deterioration
streng~h ractiO strength rate
(kg/mm) reduction (kg~mm2 seC-l~
t%) ~1200C) (1750C)
Rtemp. 1400C
_ _
Example 160 130 82 2.2 0.16
Example 161
In isopropanol were thoroughly dispersed (a) a
borosilicate glass t7740) powder (a product of Corning
Glass Works) having an average particle diameter of 44~m
and (b) 45 % by volume of chopped fibers obtained by
cutting the inorganic fiber of Example 136 into a length
of 10 mm. The resulting slurry and a plurality of the
same inorganic fibers arranged in the same direction were
- 192 -
piled up by turns~ The laminatle was dried and then
treated by a hot pressing machine at 750 kg/mm2 at 1300C
for about 10 minutes in an argon atmosphere to obtain an
inorganic fiber-reinforced glass composite material.
The results are shown in Table 290
Table 29
_
Fl~xural K Flexural Deterioration
stre~ ~ r~io strength rate 2 -1
tkgtmm ) reduction tkg~m~ .sec
(r~ (~) (9OODC) (1300C)
temp.)
~ample 161 23.U 5.1 0.25
Example 162
A plain weave fabric of the inorganic fiber
obtained in Example 127 (5) was immersed in a methanol
solution of a resole type phenolic resin (MRW-3000 manu-
factured by Meiwa Kasei) and then pulled up. The im-
pregnated fabric, after methanol was removed, was dried
~o obtain a prepreg sheet. From the prepreg sheet were
cut out square sheets of 5 cm x 5 cm. The square
sheets were piled up in a mold and pressed at 50 kg/cm
at 200C to cure the phenolic resin to obtain a molded
material. The molded material was buried in a carbon
powder and heated to 1000C at a rate of 5C/h in a
nitrogen current to obtain an inorganic fiber-reinforced
carbon composite material. The composite material was
a porous material having a bulk density of 1.26 g~cm3.
The compposite material was mixed with a powder
of the mesophase pitch (A) [this pitch is an inter-
mediate of the inorganic fiber of Example 127 t5)]. Themixture was placed in an autoclave and heated to 350C in
a nitrogen atmosphere to melt the pitch and then the
autoclave inside was made vacuum to impregnate the pores
i~ r~
-- 193 --
oE the composite material with the molten mesophase
pitch~ Thereafter, a pre~sure of 100 kg/cm2 was applied
for further impregnation. The impregnated composite
material was heated to 300C at a rate of 5C/h in air
for curing and then was carboniæed at 1300C. The above
impregnation with mesophase pitch ancl carbonization were
repeated three more times to obtain a composite material
having a bulk density of 1086 gJcm and a 1exural
strength of 39 Icg/mm~O
Using the inorganic fibers obtained in Examples
128 and 129 and in the same manner as above~ there were
prepared composite materials. The composite material
prepared using the inorganic fiber of Example 128 had a
bulk density of 1.86 g/cm3 and a flexural strength of
40 kg/mm2, and the composite material prepared ~sing the
inorganic fiber of Example 129 had a bulk density of 1.85
g/cm3 and a flexural strength of 37 kg/mm2. These com-
posite materials had a fiber content (Vf) of 60 ~ by
volume. (The Vf in the following Example 163 was also
60 % by volume.)
Example 163
A graphite powder having an average particle
diameter of 0.2 m and a powder of the mesophase pitch
(A) [the pitch is an intermediate of the inorganic fiber
f Example 127 tS)] were ground and mixed at a 1:1 weight
ratio. The resulting powder and a fabric of the in-
organic fiber of Example 131 were piled up by turns. The
laminate was hot pressed at 100 kg/cm2 at 350C to obtain
a molded material. The molded material was subjected to
four times of the same impregnation with mesophase pitch
and carbonization as in Example 162~ to obtian a composite
material having a bulk density of 1.92 g~cm3 and a
flexural strength of 42 kgimm2. When the composite
material was heated to 2500C in an argon atmosphere to
graphitize the matrix, the flexural strength improved to
50 kg/mm2.
D~
- 19~1 -
Example 16~
A plain wea~e fabric of the inorganic fiber
obtained in Example 134 was immersed in a methanol
solution of a resole type phenolic resin (MRW-3000 manu-
factured by Meiwa Kasei) and then pulled up. The im--
pregnatecl fabric, after methanol was removed, was dried
to obtain a prepreg sheet~ From the prepreg sheet were
cut out square sheets of 5 cm x 5 cm. The square sheets
were piled up in a mold and pressed at 50 kg~m2 at 200C
to cure the phenolic resin to obtain a molded material.
The molded material was buried in a carbon powder and
heated to 1000C at a rate of 5C/h in a nitrogen current
to obtain an inorganic fiber-reinforced carbon composite
material. The composite material was a porous material
lS having a bulk density of 1~25 g/cm3.
The compposite material was mixed with a powder
of the mesophase pitch which is an intermediate oE the
inorganic fiber of Example 134. The mixture was placed
in an autoclave and heated to 350C in a nitrogen atmos-
phere to melt the pitch and then the autoclave insidewas made vacuum to impregnate the pores the composite
material with the molten mesophase pitch. Thereafter,
a pressure of 100 kg/cm~ was applied for further im-
pregnation. The impregnated composite material was
heated to 300C at a rate of 5C/h in air for curing and
then was carbonized at 1300C. The above impregnation
with mesophase pitch and carbonization were repeated
three more times to obtain a composite material having a
bulk density of 1.87 g~cm and a flexural strength of 44
kg/mm2.
Using the inorganic fibers obtained in Examples
135 and 136 and in the same manner as above, there were
prepared composite materials. The composite material
prepared using the inorganic fiber of Example 135 had a
bulk density of 1.86 g/cm and a flexural strength of
45 kg/mm2, and the composite material prepared using the
5i8
- 195 -
inorganic fiber oE Example 136 had a bulk density of 1.85
gtcm3 and a flexural strength oE 39 kg/mm2. These com-
posite materials had a fiber content (Vf) of 60 % by
volume. ~The Vf in the following Example 1~5 was also
60 ~ by volume~)
Example 165
A graphite powder having an averaqe particle
diameter of 0.2 ~m and a powder of the mesophase pitch
(A) which is an intermediate of the inorganic fiber of
Example 134 were ground and mixed at a 1:1 weight ratio~
The resulting powder and a fabric of the inorganic fiber
of Example 159 ~1) were piled up by turns. The laminate
was hot pressed at 100 kg/cm2 at 350C to obtain a molded
material. The molded material was subjected to four
times of the same impregnation with mesophase pitch and
carbonization as in Example 164, to obtian a composite
material having a bulk density of 1.92 g/cm3 and a
flexural strength of 47 kg/mm2. When the composite
material was heated to 2500C in an argon atmosphere to
graphitize the matrix, the flexural strength improved to
55 kg/mm2.
Example 166
(1) The procedure of Example 134 was repeated
except that the reaction product of Example 134 (1)
(melting point = 258C, softening point = 292C) and the
mesophase pitch of Example 134 (2) were used as a ratio
of 1:1, to obtain a titanium-containing reaction product.
(2) A two-dimensional plain weave fabric of the
inorganic fiber obtair.ed in Example 134 was cut into
discs of 7 cm in diameter. The discs were impregnated
with a xylene slurry containing 30 ~ of the spinning
material polymer used in Example 134 and then were dried
to obtain prepreg sheets. These prepreg sheets were
piled up in a mold in a total sheet number of 30, with a
fine powder of the titanium-containing reaction product
of (1) above being packed between each two neighbouring
0~3~ ~3
- 196 -
prepreg sheets and with the fiber direction of one pre-
preg sheet being advanced by 45 from that of the lower
prepreg sheetO The laminate was hot pressed at 50 kg/cm2
at 350C to obtain a disc-like ~olded materialO The
molded material was buried in a carbon powder bed for
shape retention, was heated to 800C at a cate of 5C/h
in a nitrogen current, and was further heated to 1300C
to carbonize the matrixD The resulting composite
material had a bulk density of 1.20 gJcm3.
The composite material was immersed in a xylene
slurry containing 50 % of the metal-containing reaction
product of (1) above. The resulting material was heated
to 350C under vacuum while distillng oEf xylene; a
pre~sure of 100 kg/cm2 was applied for impregnation;
then, the material was heated to 300C at a rate of 5C/h
in air for curing and thereafter carbonized at 1300C.
This impregnation and carbonization treatment was re-
peated three more times to obtain a composite material
having a bulk density of 1.95 g/cm3. The composite
material had a flexural strength of 59 kg/n~2.
Example 167
There were mixed ~a) 50 parts of an inorganic
substance obtained by prefiring the spinning polymer used
in Example 159 ~1), at 1300C in nitrogen and (b) 50
parts of a powder of the titanium-containing reaction
product of Example 166 (1). The resulting mixture and a
two-dimensional plain weave fabric of the inorganic fiber
obtained in Example 159 (1) were piled up by turns. The
laminate was hot pressed at 100 kg/cm2 at 400C to obtain
a molded material. The molded material was carbonized in
the same manner as in Example 166. The resulting mate-
rial was subjected to four times of (a) the impregnation
with the titanium-containing reaction product of Example
166 (1) and (b) carbonization, in the same manner as in
Example 166. The resulting composite material had a
bulk density of 2.02 gJcm3 and a flexural strength of
3~8
- ~97 ~
61 ky/mm~0 When the composite material was pyrolyzed at
2200C in argon, the bulk density and flexural strength
improvecl to 2005 g/cm3 and 65 kl3/mm~, respectiYelyO
Example 168
(l~ The procedure of Example 135 was repeated
except that the reaction product which is an intermediate
of the inorganic fiber of Example 135 and the mesophase
pitch were used at a 1:1 ratio, to obtain a zirconium-
containing reaction product.
(2) The procedure o Example 166 was repeated
except that as a reinforcing fiber there was used the
inorganic fiber of Example 135~ there was usedt as a
polymer for prepreg sheet preparation, the spinning
polymer used in Example 135, and as a packing powder used
in molding there was used the zirconium~containing re-
action product of (1) above, whereby a composite material
having a bulk density of 1.21 gtcm3 was obtained~
The composite material was subjected to the
impregnation with the zirconium-containing reaction
product of (1) above in the same manner as in Example
166, to obtain a composite material haYing a bulk density
of 1.97 g/cm3 and a flexural strength of 61 kg/mm2.
Example 169
tl) The procedure of Example 136 was repeated
except that the reaction product which is an intermediate
of the inorganic fiber of Example 136 and the mesophase
pitch were used at a 1:1 ratio, to obtain a hafnium-
containing reaction product.
(2~ The procedure of Example 166 was repeated
except that as a reinforcing fiber there was used the
inorganic fiber of Example 1369 there was used, as a
polymer for prepreg sheet preparation, the spinning
polymer used in Example 136, and as a packing powder used
in molding there was used the metal-containing reaction
product of (1) above, whereby a composite material having
a bulk density of 1.25 g~crn3 was obtained.
- 19~ -
The composite material was subjected to the
impregnation with the hafnium-c~ntaining reaction
product of (1) above in the same manner as in Example
156, to obtain a composite material having a bulk density
of 2O05 g/cm3 and a flexural strength of 56 kg/mm2.
Example 170
The composite materlals of Examples 166, 167.
168 and 169 were heated for 1 hour in an oven containing
air of 600C and then measured Eor flexural strength.
There was seen no strength reduction in any
composite material (see Comparative Examples 33 and 34).
Example 171
(lj 6.4 g of the precursor reaction product used in
preparation of the inorganic fiber of Example 134 and 90
g f a mesophase pitch were melt mixed for 1 hour at
380C in a nitrogen atmosphere to prepare a reaction
product.
(2) S0 g of the organic polymer used in preparation
of the inorganic fiber of Example 134 and 5Q g of a
reforming pitch were treated in the same manner as in
Example 134 to obtain a precursor reaction product. This
precursor reaction product and the mesophase pitch of
Example 134 were melt mixed at a 1:1 ratio for 1 hour at
380~C in a nitrogen atmosphere to obtain a reaction
product~
(3) A two-dimensional plain weave fabric oE the
inorgnaic fiber obtained in Example 13~ was cut into
discs of 7 cm in diameter. The discs were immersed in a
xylene slurry containing 30 % of the reaction product of
(1) above and then were dried to obtain prepreg sheets.
These prepreg sheets were piled up in a mold in a total
sheet number of 30, with a fine powder of the reaction
product of ~2) above being packed between each two nei-
bouring prepreg sheets and with the fiber direction of
one prepreg sheet being advanced by 45 from that of the
lower prepreg sheet. The laminate was hot pressed at
2 - 199 _
50 kg/cm at 350C to obtain a disc-like molded material.
The molded material was buried in a carbon powder bed
for shape retentiorl, was heated to 800C at a rate of
5~C/h in a nitrogen current~ and was further heated to
1300C to carbonize the matrix. The resulting composite
material had a bulk density of 1.21 g/cm ~
The composite material was immersed in a xylene
slurry containing 50 % of the reaction product of (2)
above. The resulting material was heated to 350C under
1~ vacuum while distilling off xylene~ a pressure cf 100
kg/cm2 was applied for impregnation; then, the material
was heated to 300C at a rate of 5C/h in air for curing
and thereafter carbonized at 1300C. This impregnation
and carbonization treatment was repeated three more tirnes
to obtain a composite material having a bulk density o
1.93 9/cm3. The composite material had a flexural
strength of 57 kg/mm2.
Example 172
There were mixed (a~ 50 parts of an inorganic
substance obtained by prefiring the reaction product of
Example 171 (1) at 1300C in nitogen and (b) 50 parts of
a powder of said reaction product. The resulting mixture
and a two-dimensional plain weave fabric of the inorganic
fiber obtained in Example 159 (1) were piled up by turns.
The laminate was hot pressed at 100 kg/cm2 at 400C to
obtain a molded material. The molded material was carbo-
nized in the same manner as in Example 171. The result-
ing material was subjected to four times oE (a) the
impregnation with the reaction product of Example 171
(2) and (b) carbonization, in the same manner as in
Example 171. The resulting composite material had a bulk
density of 2.00 g/cm3 and a flexural strength of 59
kg/mm . ~hen the composite material was pyrolyzed at 2200C
in argon, the bulk density and flexural strength improved
to 2O03 gicm3 abd 63 kg/mm~, respectively~
- 200 -
Example 173
A composite material having a bulk density of
1.20 g/cm3 was obtained in the same manner as in Example
171 except that as a reinforcing fiber there was used the
inorganic fiber of Examp:Le 135.
The material was subjected to the impregnation
with the reaction product of Example 171 ~2) .in the same
manner as in Example 171 to obtain a composite material
having a bulk density of 1~96 g/cm3 and a flexural
Strength Of 59 kg~mm2
Example 17~
(1) The procedure of Example 171 was repeated
except that as a reinforcing fiber there was used the
inorganic fiber of Example 136, to obtain a composite
mater.ial having a bulk density of ln24 g~cm3.
The material was subjected to the impregnation
with the reaction product of Example 171 (2) in the same
manner as ln Example 171 to obtain a composite material
having a bulk density of 2.03 g/cm3 and a flexural
strength of 54 kg/mm2.
Example 175
The composite materials of Examples 171, 172,
173 and 174 were heated for 1 hour in an oven containing
air of 600C and then measured for flexural strength~
No strength reduction was seen in any COJnpOSite
material.
Example 176
A fiber was prepared using an apparatus of Fig.
1. 250 9 of silicon carbide fine particles (average
3n particle diameter = 0.28 m) was placed in a treactîng
tank containing 5,000 cc of ethyl alcohol. Ultrasonic
vibration was applied by an ultrasonic applicator 2 to
suspend the fine particles in ethyl alcohol and thereby
to prepare a treating solution 3.
A continuous fiber bundle 4 of the inorganic
fiber obtained in Example 134 was unwound from a bobbin
~ r r~ r~ ~
-- :?,01 --
5 and passed through ~he ~reating solution 3 with the
passing time controlled at about 15 sec~ by movable
eollers 6 and 7. (Durny the passiny, an ultrasonic wave
was applled to the treating solution 3 and the solution 3
was stirred with air beir.g blownO) Then~ the continuous
fiber bundle was pressed by pressure rollers 8 and 9,
wound up by a bobbin 10, and dried at room temperature in
air.
Weighin~ of the fiber after the treatment
indicated that 7 ~ by volume of the fine particles
attached to the fiber.
Example 177
The same treatment as in Exarnple 176 was re-
peated except that as the treating solution in the
treating tank 1 there was used a slurry obtained by
suspending 100 g of silicon carbide whiskers (average
diameter: about 0.2/~m, average length: about 100 rn) and
250 9 oE silicon carbide fine particles (average particle
diameter: 0.28~ m) in 5,000 cc of ethyl alcohol.
The fiber obtained had a grayish green color.
Observation of the fiber by an electron microsocpe (SEM)
indicated that mainly fine particles attached to the
surface of each continuous fiber and further mainly
whi~kers attached thereonto. IYeighing of the fiber
indicated that 10 % by volume of the fine particles and
whiskers attached to the fiber.
Separately, a continuous fiber bundle of the
inorganic fiber of Example 159 (1) was subjected to the
same treatment as above to obtain a fiber to which 8 % by
volume of fine particles and whiskers attached.
Example 178
A continuous fiber bundle 4 of the inorganic
fiber obtained in Example 135 was treated in the same
manner as in Example 176 except that as a treating
solution there was used a suspension obtained by sus-
pending 100 g of silicon nitride whiskers (average
~0~ 8
- 202 --
diameter: about 0~3 m, average length about 200 m) and
100 g of the above mentioned silicon carbide Eine par-
ticles in 5,000 cc of waterO As a result, about 5 % by
volume of the fine particles asld whiskers attached to the
continuous fine bundle 4O
Example 179
A continuous fiber bundle 4 of the inorganic
fiber obtained in Example 136 was passed through a sus-
pension obtained by stirring 100 g of silicon carbide
fine particles in 500 cc of ethanol, while applying an
ultrasonic wave to the suspension. Then, the fiber
bundle was passed through a suspension obtained by stir-
ring 150 g of silicon nitride whiskers in 500 cc of
ethanol, in the same manner and then dried. As a result,
about 14 % by volume of the fine particles and whiskers
attached to the fiber bundle.
Example 180
The titanium-containing reaction product which
is a spinning material for preparation of the inorganic
fiber of Example 134 was finely ground and then pyrolyzed
at 1300C in an argon current to obtain a fine powder
having an average particle diameter of 0.5~ m and con-
sisting of crystalline carbon, amorphous carbon and an
amorphous material composed mainly of Si-C-O. 100 g of
this fine powder was suspended in 500 cc of ethanol by
stirring. A continuous fiber bundle 4 of the inorganic
fiber obtained in Example 134 was passed through the
above suspension while applying an ultrasonic wave to the
suspension. The fiber bundle was then passed through a
suspension obtained by suspending 150 g of silicon
nitride whiskers in 500 cc of ethanol by stirring, in the
same manner and then dried. As a result, about 12 ~ of
the fine particles and whiskers attached to the fiber
bundle.
Example 181
Using the fiber obtained in Example 176 and
~,~ 3
~ 203 -
~an aluminum matrix~ there was pre~pared a unidirectionally
reinfQrced FRM. The FRM had a fiber volume fraction (vf)
of 50 ~ and a flexural strengkh of 179 kg/mm2 (the ROM
value was 190 kg/mm23.
Example 182
Using the fiber obtained in Example 177 from
the inorganic fiber oE Example 13~ and, as a matrix,
aluminum containing 5 ~ in total of copper and magnesium,
there was prepared a unidirectionally reinforced FRM.
The FRM had a fiber volume fraction of 50 %. Its flexu-
ral strength was 185 kgJmm2 and was scarcely different
from the ROM value (190 kg~mm ~.
Using the fiber obtained in Example 177 from
the inorganic fiber of Example 159 (1) and in the same
manner, there was prepared a FRM. The FRM had a flexural
strength of 175 kg/mm2, which was scarcely different from
the ROM value (173 kg/mm ).
Example 183
The inorganic fiber of Example 134 ~as uni-
directionally arranged on a pure aluminum foil (specifiedby JIS 1070) of 0 5 mm in thickness. Thereon was placed
another aluminum foil of same quality and size. The
laminate was subjected to hot rolling at 670C to prepare
a composite foil of fiber and aluminum. The composite
2S foil was piled up in a total sheet number oE 27, was
allowed to stand for 10 minutes at 670C under vacuum,
and then subjected to hot pressing at 600C to obtain an
inorganic fiber-reinforced aluminum composite material.
The inorganic fiber was measured for initial deteriora-
tion rate (kg/mm2~sec 1) and fiber strength reduction(%). The composite material was measured for tensile
strength in fiber direction (kg/mm2~, tensile modulus of
elasticity in fiber direction (t/mm2), interlaminar shear
strength (kg/mm ) r tensile strength in direction per-
pendicular to fiber (kg/mm2) and fatigue limit/tensile
strength. The results are shown in Table 30. The Vf of
the composite material was 30 ~ by volume~
- 204 -
For reference, the results of Comparative
Example 42 are also shown in Table 30.
Table 3Q
Comparative
~ Example ~2
Initial det2riora~ion
rate (kg~mm .sec ~ 0.7 3~2
Fiber s~.rength
reduction (%) 51 90
Tensile strength in
fiber direction (kg/mm2) 55 25
Tensile modulus of
elasticity in f~ber
d.irection ~t/mm ) 12.1. 6.5
Interlaminar sh~ar
strength (kg/mm ) 5.4 2.2
Tensile strength in
direction perpe~dicular
to fiber (kg/mm ) 4.3 1.8
Fatigue limit/
tensile strength 0.39 0~25
Example 184
A fiber-reinforced metal was prepared in the
same manner as in Example 183 except that there was used
an aluminum alloy foil (specified by JIS 6061). The
inorganic fiber and the fiber-reinforced metal were
measured for the above mentioned properties. The results
are shown in Table 31. The results of Comparative
Example 43 are also shown in Table 31.
Table 31
Comparative
Example 184 Example 43
Initial det~riora~ion
rate tkg/mm .sec -) 1.0 3.9
Fiber strellgth
reduction t%) 55 95
Interlaminar sh~ar
strength ~kg~mm ) 11.2 4.0
Tensile strength in
direction perpe~dicular
to fiber (kg/mm ) 9.1 3.2
Fatigue limit/
tensile strength 0.42 0.25
Example 185
A plurality of the inorganic fibers of Example
135 were arranged unidirectionally and coated with
metallic titanium in a thickness of 0.1-lO~L by the use
of a thermal spraying apparatus. This coated inorganic
fibee layer was piled up in a plurality of layers with a
titanium powder being packed between each two neighboring
lQ layers. The laminate was press molded. The molded
material was prefired for 3 hours at 520C in a hydrogen
atmosphere and then hot pressed at 200 kg/cm2 at 1150~C
for 3 hours in an argon atmosphere to obtain an inorganic
fiber-reinforced titanium composite material.
The inorganic fiber was measured for initial
deterioration rate (kg/mm2.sec 1) and fiber strength
reduction (%), and the composite material was measured
for tensile strength in fiber direction (kg~mm2~,
interlaminar shear strength ~kg/mm2), tensile strength in
direction perpendicular to fiber (kg/mm2) and fatigue
limit/tensile strength. The results are shown in Table
32.
- 206 -
The tensile strength in fiber direction, of the
composite material was 137 kg/mm2, which was about two
t:imes the tensile strength of metallic titanium alone.
The Vf of the composite materia3. was 45 % by volume.
The results of Comparative ~xample 44 are also
shown in Table 32~
Table 32
Comparative
Example 185 Example 44
Initial det~riora~ion
rate ~kg/mm .sec ~ 0.8 3O7
Fiber strength
reduction ~%) 49 95
Tensile strength in 2
f.iber direction (kg/mm ) 137 52
Interlaminar sh~ar
strength ~kq/mm ) 14.~ 4.7
Tensile strength in
direction perpe~dicular
to fiber (kg~mm ) 10.1 3.8
Fatigue limit/
tensile strength 0.39 0~20
Example 186
A plurality of the inorganic Eibers of Example
135 were arranged unidirectionally and coated with a
titanium alloy ~Ti-6Al-4V) in a thickness of 0.1-10 ~ by
the use of a thermal spraying apparatus~ This coated
inorganic fiber layer was piled up in a plurality of
layers with a titanium powder being packed between each
two neighboring layers. The laminate was press molded~
The molded material was prefired for 3 hours at 520C in
a hydrogen gas atmosphere and then hot pressed at 200
kg/cm2 at 1150C for 3 hours in an argon atmosphere to
obtain an inorganic fiber-reinforced titanium composite
material.
'
- 207 -
The inorganic fiber Wc15 measured for initial
deterioration rate tkg/mm2~sec ]L) and fiber strength
reduction (~) r and the composite material was measured
for interlaminar shear strength (kg~mm2~, tensile
strength in direction perpendicular to fiber ~kg/mm2) and
fatigue limititensile strength. The Vf of the composite
material was 45 ~ by volume. The results are shown in
Table 33.
The results of Comparative Example 45 are also
lQ Shown in Table 33.
Table 33
Comparative
Example 186 Example 45
Initial det~riora~ion
rate (kg/mm .sec ) 0.8 4.0
Fiber strength
reduction (%) 50 96
Interlaminar sh~ar
strength (kg~mm ) 20.1 7.4
Tensile strength in
direction perpe~dicular
to fiber (kg/mm ) 16.5 6.D
Fatigue limit/
tensile strength 0.39 0.19
Example 187
On a pure magnesium foil of 0.5 mm in thickness
were unidirectionally arranged a plurality of the in
organic fibers of Example 136. Thereon was placed
another magnesium foil of same quality and size. The
laminate was hot rolled at 670C to obtain a composite
foil of fiber and magnesium. This composite foil was
piled up in a total number of 27, was allowed to stand
for 10 minutes at 670C under vacuum, and then was hot
pressed at 600C to obtain an inorganic fiber-reinforced
magnesium composite material.
- 208 -
T}le inorganic fiber was measured for initial
deterioration rate (kg~mm2~sec 1) and fiber strength
reduction (~), and the composite material was measured
for interlaminar shear strength (kg/mm23, tensile
streng-th in direction perpendicular to fiber ~kgimm2) and
fatigue limit/tensile strength. The Vf of the composite
mater:ial was 30 ~ by volume. The results are shown in
Tab~e 34~
The results of Comparative ~xample 46 are also
shown in Table 3~O
Table 34
Comparative
Example 187 Example 46
Initial det~riora~ion
rate ~kg~mm .sec ~ 0~9 4.1
Fiber strength
reduction (%) 60 96
Interlaminar sh~ar
stren~th (kg/mm ) 4.6 1.5
Tensile strength in
direction perpe~dicular
to fiber (kg/mm ) 3.7 1.3
Fatigue limit/
tensile strength 0.37 0.21
Example 188
A plurality of the inorganic fibers of Example
136 were undirectionally arranged on a magnesium alloy
foil (specified by JIS A 891) of 0.5 mm in thickness.
Thereon was placed another magnesium alloy foil of same
quality and size. The laminate was hot rolled at 670C
to prepare a composite foil of fiber and magnesium alloy.
This composite foil was piled up in a total number of 27,
was allowed to stand for 10 minutes at 670~C under
vacuum, and was hot pressed at 600C to obtain an in-
organic fiber-reinforced magnesium composite material.
5;~
- 209 -
The inorganlc fiber was measured for initial
deterioration rate ~kg/mm2~sec L) and fiber strength
reduction (~, and the composite material was measured
for interkaminar shear strength (kg/mm2~, tensile
strength in direction perpendicular to fiber (kg/mm2) and
fatigue limit/tensile strength~ The Vf of the composite
material was 30 ~ by volume. The results are shown in
~able 35.
The results of Comparative Example 47 are also
Shown in Table 35,
Table 35
Comparative
Example 188 Example 47
Initial det~riora~ion
rate (kg/mm .sec ) 0.9 4O0
~iber strength
reduction (~) 60 96
Interlamînar sh~ar
strength (kg/mm ~ 7.5 2.8
Tensile strength in
direction perpe~dicular
to fiber (kg/mm ) 6.1 2.2
Fatigue limit~
tensile strength 0.40 0.27
Example 189
An inorganic fiber-reinforced aluminum com-
posite material was prepared in the same manner as inExample 183 except that there was used the inorganic
fiber of Example 159 (1). The tensile strength of the
composite material was about the same as that of the
composite material obtained in Example 183, but the
tensile modulus of elasticity was greatly improved to
24.5 t/mm . The Vf of the composite material was 30 % by
volume.
