Note: Descriptions are shown in the official language in which they were submitted.
1 324469
PROCESS FOR PRODUCING CARBON MATERIALS
BACRGROUND OF THE INVENTION
. . .
1) Field of the Invention:
' 5 This invention relates to a process for
producing carbon materials whicb can be used either in - ::
the form of fibers or va3ious molded articles as fillers
for various composite materials, heat insulating mate-
rials and ablation materials, or in the form of activated
carbon materials including molecular sieve carbon
materials, activated carbon fibers and the like as
adsorbent or separating materials.
2) Description o~ the Related Art:
Among carbon materials in such fibrous forms
as generall~ called carbon fibers, molecular sieve `-`
carbon fibers or activated carbon fibers, carbon fibers
are produced by spinning rayon, lignin, polyacrylonitrile
_ ~herainafter referred to as PAN~, pitch or the like,
20 rendering the spun fiber infusible, carboni2ing it at `
a temperature of 1,000 to 1,600C,,or further graphitiz- ;
ing the resulting carbon fiber at a temperature of :~
2,000 to 3,000C. On the other hand, molecular sieve :~
. ~.
carbon fibers and activated carbon fibers are produced
25 either by spinning a raw material as described above, ` .
~ ` ' "
~ .''. . ':
:~ ...,, :...
l 32446q
rendering the spun fiber infusible, and then activating
it, or by rendering the spun fiber infusible, carbonizing
it, and then activating the resulting carbon fiber.
Although these carbon materîals in fibrous
form have excellent properties which are not possessed
by other materials, they involve`several operational
problems as described in~the f~llowing paragraphs (1)
to ~3). Therefore, these carbon materials are high in
price and still far from being widely used as common
industrial materials~
(1) In order to provide industrially practicable
spinnability, the spinning material must previously
be freed of any for~ign matter by hiqh-precision
filtration.
(2) Rayon and PAN are spun according to the wet or dry
spinning te~hnique, which involves the cost of
solvent recoYery. On the other hand, the spinning
of lignin and pitch produces tar and mist, so that
it is important to control the spinning atmosphere.
_ 20 (3) All of the fibers spun from the aforesaid raw
~.
materials require a treatment for rendering them - -
infusible. Generally, this treatment is carried -
out by air oxidation. In,this treatment, a long
treating time, l~rge-capacity oxidizing equipment
and the like are needed to prevent violent
exothermic reaction, i.e., combustion. -`
:
1 324469
In order to eliminate the time-consuming step
of rendering the spun fiber infusible by air oxidation,
there has been proposed a process in which fibrous
polystyrene is soaked in sulfuric acid and then carbonized
(Japanese Patent Publication No. 36085/'86). However,
this process has the disadvantage that the sulfonation
of polystyrene (i.e., the introduction of sulfonic groups
into polystyrene) is not ~ffected uniformly throughout
the entire fiber. That is, spots rendered infusible,
spots made fragile due to excessive sul~onation, and
spots not rendered infusible are formed in the fiber
surfaces, resulting in a very inhomogeneous ~iber.
, ~
SU~NARY OF THE INVENTION
lS It is the primary ob~ect of the present
in~ention to provide a process for producing carbon `
ma~erial~ by ~hich the abovè-described problems of the
prior art can be solved and in which carbon materials
ha~ng the form of fibers or molded articles (such as
honeycQmbs) and useful as components for various
composite materials and as adsorbent or separating
materials can be produced by easy and simple operation.
In view of ~he above and other objects, the
present inventors have made an intensive inveatigation
and have found that the above-described problems can
be solved by using a methylene type linkage-containing
1 324469
condensation product of an aromatic sulfonic acid or a
salt thereof as the spinning or moldinq material. The
present invention has been completed on the ~asis of
this finding.
According to the present invention, there is
provided a process for producing carbon materials which
comprises the steps of p~eparing a raw material -
composition comprising a methylen type linkage-containing
condensation product of an aromatic sulfonic acid or a
salt thereof and a solvent, the condensation product
having been formed by means of a linkage of the formula
-(CH2)n-Tx (CHR~m (1)
where T is a benzene or nap~hthalene ring, R is a hydrogen
atom, an alkyl group of 1 to i carbon atoms, or a
ben~ene ring, and each of n, m and x is 0 or 1, but n
and m should not be zero at the same time; spinning or
molding the raw material composition; and carbonizing
the spun fiber or molded article.
~ ~ .
DETAIL~D DESCRIPTI~N OF THE IN~ENTION
_
Specific examples of the aromatic sulfonic ~ -
acid, or salt thereof, which is used in the present
invention include naphthalenesulfon~c acid, anthracene-
sulfonic acid, phenantbrenesulfonic acid, sulfonated
. .
~ , . ' ~ . ~ ' . . '
1 324469
products of polycyclic aromatic compound mixtures
(such as creosote oil, anthracene oil , tar and pitch),
toluenesulfonic acid, xylenesulfonic acid, sulfonated
phenols and mixtures thereof, as well as salts of the
foregoing. These aromatic sulfonic acids can be
: obtained by sulfonàting the corresponding àromatic
compounds according to an~ of vario~s well-known methods.
Although ~he cation constituting salts of the aromatic
sulfonic acids can be Na~, K~, Ca~2, NH4~ and the like,
10 ammonium salts are preferred because of the ease with ~ ~`
~hich the spun fiber can be handled in the carbonization
step. Moreover, preferred salts may vary according to
the desired type of carbon material. That is, ammonium
salts are preferred for the productàon of carbon -
materials re~uirin~ strength. In order to produce
porous adsorbent materials or separating materials, ` `
ammonium salts can be used satisfactorily, but sodium
and calciu~ salts are more preferred.
Condensation product~ of the above-described `` 20 aromatic sulfonic acids or salts thereof can be prepared
according to any of various well-known methods. However,
it is common practice to condensate an aromatic sulfonic
acid or a salt thereo~ with the aid of formalin, `
paraformaldehyde, hexamethy}enetetramine or other
aldehyde. It is also possible to use a methylene type
linkage-containing polymer (such as polystyrenesulfonic
1 324469
acid) obtained by polymerizing an aromatic sulfonic
acid having a vinyl group. Although the linkage connect-
ing molecules of the aromatic sulfonic acid may be
any of the linkages within the scope of formula (1),
the -CH2- linkage is especially preferred because
` methylene-linked condensation products are easy to
prepare or obtain. And ~he linkage in a methylene type
linkage-containing condensation product of an aromatic
sulfonic acid or a salt thereof as said in the present
invention, includes not only those which connect
directly with an aromatic ring but also those which
connect by means of side chains as in the case of a
polystyrenesulfonic acid.~
Various types of condensation products can
be obtained, depending on the type of aromatic compound
us~d, the conditions of sulfonation and condensation
reactions, and the like. Of course, these condensation
pr~ducts may be used alone or in admixture of two or more,
and may also be used in the form of polycondensation
_ 20 products.
As an example of the methylene type linkage-
containing condensation product of aromatic sulfonic
acid, or salt th~reof, which is used in the process of
the present invention, mention is made of a condensation
product obtained by condensing ammonium naphthalene-~-
sulfonate with the aid of formaldehyde. This condensation
' .:`
. ,"., ~; ;; .
1 32446q
product is a mixture of monomer and various polymers
having polymerization degrees of up to about 200, and
has a number-average molecular weight of about 2,000
to 50,000. This condensation product is a solid at
ordinary temperatures, sparingly soluble in organic
solvents such as benzene,~toluene and acetone, and
readily soluble in aqueous solvents. A 60~ ~w/w)
aqueous solution thereof~has a viscosity of about 10
to 20,000 poisas at 60C and exhibits adequate `.
10 spinnability and moldability. When this condensation .
product is carbonized at a temperature of 800 to
1,000C, the yield of the resulting carbon material is
.. ~: .... .
about 50% by weiqht~
The above-described condensation product is
only one example of the condensation products useful
in the process of the present invention, and it is to
be understood that the range of the polymerization
de~ree, or number-average molecular weight, of a : .
condensation product useful in the process of the present 20 invention depends on the type of the aromatic sulfonic
acid, or salt thereof, constituting the condensation
product. For example, a useful condensation product ~ :
of sulfonated creosote oil is a mixture of monomer and
various polymers having polymerization degrees of ~.
25 up to about 40, and has a number-average mo~ecular ~:
weight of about 2,000 to about 5,000. A useful ~;
' :
~' ':' ' .
1 324469
condensation product of phenanthrenesulfonic acid
is a mixture of monomer and various polymers having
polymerization degrees of up to about 30, and has a
number-average molecular weight of about 2,500 to about
5,000.
T~e above-definèd condensation product or
polymer of aromatic sulfonic acid or salt thereof is
dissolved or dispersed i~p~a solvent to prepare a
raw material composition. If necessary, the viscosity
of this raw material composition is adjusted by suitable
means such as dilution and concentration. Then, the
ra~ material composition is spun into fibrous form or
molded into any desired shape such as block, column,
plate, film or honeycomb. Finally, the spun fiber or
molded article is carbonised to obtain a carbon
material.
In view of the properties of t~ë condensation
product or polymer of aromatic sulfonic acid or salt
thereof, the solvent used in the process of the present
_ 20 invention is preferably selected from polar solvents
`
including water, alcohols (such as methanol), aceto-
nitrile and the like. Among others, it is most
preferable to use water or an aqueous solvent comprising
a mixture of water and a suitable water-soluble solvent.
Where a carbon material in fibrous ~orm is to
be produced by the process of the present invention, it -
1 324469
g
is undesirable that the aromatic sulfonic acid used
as the raw material contains a high proportion of
unsulfonated aromatic compounds, because they make -
the resulting carbon fibers inhomogeneous and cause a
reduction in strength. In such a case, the methylene
type linkage-containing condensation products of
unsulfonated aromatic cQ~pounds can be removed by .
using water as the solve~nt. That is, since the
methylene-linked condensation products of unsulfonated
aromatic compounds àre hardly soluble in water and,
therefore, can be separated from the spinning solution .`
i~ according to suitable techniques such as filtration, .
centrifugation and dialysis. Moreover, the use of an
agueous solvent is preferred from operational points `.`
of view, because the spinning atmosphere can be
controlled easily.and there is no risk of ignition or
explosion.
In the process of the present invention, the . .
spinnability and moldability of the raw material ` ;
composition can further be improved by adding a water~
soluble polymeric compound, as a spinning or molding
aid, to the raw material composition in an amount of :
0.02 to 20 parts by weight per 100 parts by weight .:
of the solid constituent of the raw material composition.
25 The water-soluble polymeric compound used in the present~ .
invention can be any of various polymeric compounds ~.
1 324469
-- 10 --
that are soluble or colloidally dispersible in water
and aqueous solvents. Especially preferred are poly-
alkylene oxid~ compounds such as condensation products
of ethylene oxide, propylene oxide, etc., and condensa-
tion products obtained by ~he reaction of these compounds
: with various alcohols, fatty acids, alkylamines andalkylphenols; polyvinyl cQmpounds such as polyvinyl
alcohol and polyvinyl py~rolidone; polyacrylic compounds
such as polyacrylic aci~, polyacrylamide and acrylic
acid-acrylamide copolymer; and the like. Among the
methylene-linked condensation products of aromatic
sulfonic acids, or salts thereof, which can be used as
the raw material in the process of the present invention,
those having high solubility in water ~such as poly-
styrenesulfonic acid) can also be used as the water-
so}uble polymeric compound. The addition of such a
~ater-soluble polymeric ~ompound is effective in ~`
accelerating the spinning speed, making it easy to ` `
handle the spun fiber or molded article prior to 20 carbonization, and increasing the strength of the
resulting carbon fiber or molded product. If the amount
of water-soluble polymeric compound added is less than
0.02 part by weight, a satisfactory effect cannot be
obtained. If it is greater than 20 parts by weight,
the fiber or the }ike is liable to fusion during the
heating operation for carbonization. This is undesirable
1 324469
11 --
because a separate step of rendering it infusible is
required.
As described above, the methylene type linkage-
containing condensation product of aromatic sulfonic
acid or salt thereof, which is used in the process of
: th`e present invention, can be spun or molded and then
carbonized to produce ca~bon materials in fibrous form
and in various other forms. However, on the basis of `~
the feature that the aforesaid condensation product can
be carbonized without being rendered infusible, the
process of the present il~vention is particularly suitable
for the production of caxbon materials in fibrous form.
The content of the condensation product in
the raw material composition for spinning ~i.e., the
15 spinning material) may vary according to the types of :
the condensation product~ water-soluble polymeric
co~pound and solvent. ~owever, it is qenerally in the ` `
r~nge of 20 to 80~ by weight and preferably in the range
o~ 40 to ?0~ by weight.
_ 20 In the spinning material liquid there are
sometimes produced impurities from the raw materials
or derivative substances, whether in solid or gel,
resulted from reaction by-products among the raw matèrials. -
The removal of such i~purities or substances is effective
in gaining a high-spinnability or an improved q~ality of
carbon materials in fibrous form. Though it can be made
1 324469
- 12 -
outside a spinning machine, the removal can be far
effectively carried out by placing a sintered metal
filter, a sintered metal fibrous filter, a sintered
metal wire netting filter or a pack filter of various
metal fillers upon a spinneret.
The spinning temperature may vary according
to the composition of t~è spinning material, the desired
shape of fiber, and the like. However, where water is
used as the solvent, the spinning temperature is
preferably in the range of 20 to 100C. The fiber
emerging from the spinnerlet is drawn out by means of a
wind-up roll, godet rolls, an air sucker or the like, is
wound up or is accumulate~ in a receiver after having
been dried within a barrel dryer equipped under the
spi~neret, preferably in a heated-air stream flowing
in parallel to the progress of the ~iber. A draft ratio
~i.e., the spinneret's di~meter/the spun fiber's
diameter) where thè fiber is drawn out, can be 100 to
2; however, a preferable range of it is 10 to 5. A 20 fiber ~ith a big surface can be also produced by apply-
ing a spinneret of irregular form in order to ease
the drying of the fiber and enhance the fibrous strength. -
Although the diameter of the spun fiber may be determined
aribitrarily, it is preferably in the range of 2 to 100
, .
25 ~m and more preferably in the range of 8 to 20 ~m. `
There is a possibility that the spun fiber
.
- 1 324469
might absorb humidity and melt into another one because
of its hygroscopicity if it is left for a long time
in the open air. Accordingly, it is favorable soon to
send the spun ~iber to the carbonization process or
to stock it in the dry air when necessary.
According to the process of the present
invention, the spun fiber can be carbonized without being
rendered infusible~ In the carbonization process the
spun fiber is fired by heating at a thermal ascending
speed of 1 to 2,000C/min., preferably 10 to 500C/min.,
up to a temperature of 500 to 2,000C, but under a -~
non-oxidation atmosphere such as in a stream of N2 or -
oth~r non-activated gases~ "
In the case of the raw material being an
ammonium salt of a methylene type condensation product
of an aromatic sulfonic acid,`a sulfurous acid and an "
ammonium root are eliminated in the principal range of
2~0 to 350C during the carbonization, when the raw
material of about 50% by weight is lost. In order to
_ 20 prevent the derogation of fibrous quality owing to a
. _ . .
sudden elimination of volatile matters, it is favorable
that thermal ascending is made at a gentle speed in
the range of 250 to 350C or that a thermal retention
time in the same thermal range is included in a thermal
proqram for the carbonisation. The fiber may further
be fired at a temperature of 2,000 to 3,000C to obtain
- 1 324469
a carbon fiber comprising graphite. In addition, its
properties (e.g., tensile strength~ can further be
improved by drawing the fiber during the firing
operation.
Where a carbon material in the form of a
molded article is to be produced by the process of the
present invention, the cdntent of the condensation
produ`ct in the raw mate * al composition for molding
(i.e., the molding material) may vary according to
the types of the condensation product, water-soluble
polymeric compound and solvent. Rowever, it is generally
i~ in the range of 20 to 90% by weight and preferably in
the range of 40 to 80% by~weight.
The molded article can be carbonized under ~ `
substantially the same conditions as employed for the
spun fiber.
In a preferred em~odiment of the present
invention, a continuous process can be established ~`
which comprises sulfonating~the aromatic compound used
_ 20 as the raw material, condensing it with the aid of
,~,
formalin or the li~e while controlling the water
content and pR of the r~action system, neutralizing the
condensation product, removing any"insoluble matter
~ccording to the needr adjusting the viscosity of the
. .
condensation product ~e.g., by controlling its water
content) to prepare a spinning or molding material,
,'~.' . ': .
"'','',,.
"' .:
1 324469
- 15 -
spinning or molding it, and then carbonizing the spun
fiber or molded article to obtain a carbon material.
Moreover, better results can be obtained by adding the
above-described water-soluble polymeric compound at
the time of prep~ration of the spinning or molding
material.
The properties`of carbon fibers produced by
the process of the present invention will vary according
to the type of the aromatic compound, or salt thereof,
1~ used in the spinning material, the diameter of the
fiber, and the like. More specifically, the strength
of the resulting fiber increases with a rise in carboniza-
tion temperature. For example, the fi~er fired at
600C has a strength of 20 to 50 kg/mm2 and the fiber `
fired at 1,200C has a strength of 40 to 200 kg/mm2.
The carbon materials produced by the process
of the present invention have a relatively }arge specific
surface area because the elimination of sulfonic groups
occurs in the carbonization step. Moreover, since 20 the ra~ material is sulfonated while it is in the low-
molecular-weight state, the sulfonic groups are
distributed evenly. Therefore, the carbon materials
produced by the present invention are more homogeneous
and have more excellent properties than those produced
by conventional met~ods such as the treatment of polymers
with sulfuric acid. These carbon materials, especially
"
1 32~469
- 16 -
in fibrous fonm, can be used as fillers for various
composite materials and as heat insulating materials.
Moreover, by further subjecting them to an activation
treatment, they can also be used as adsorbent or
separating materials, including molecular sieve carbon
materials, activated carbon fibers and the like.
The activation ~reatment can be carried out in
the same manner as for the preparation of ordinary
activated carbon and the like. Specifically, the carbon
materials of the present invention may be activated by
suitable gases such as steam, air and C02 or by suitable
i~ chemicals such as 3inc chloride or sulfuric acid. ~
The activation treatment may be carried out ` `
after the spun fiber or molded article has been carbonized,
or while the spun ~iber or molded article is being
carbonized.
In one embodiment of the activation treatment
using steam as the activator, the spun fiber or molded `
article ~not carbonized) is heated at a temperature of
20 350C or above, preferably 450C or above, in an `
atmosphere of an inert gas and then treated with steam
at a t~mperature of 700 to 900C for 10 to 120 minutes.
Where an activator (such as C02) involving
no risk of dissolving the spun fiber or molded article
is used, the spun fiber or molded article may be
directly treated with steam at a temperature of 700 to
1 324469
- 17 -
1,000C for lo to 180 minutes without heating at a
lower temperature.
As a result of the above-described activation
treatment, there is obtained an activated carbon mate-
r al having a specific surface area of 500 to 2,500
; m /g as measured by the N2 BET method.
According to th~ process of the present
invention, carbon materials having excellent properties
and useful in wide applications can be produced by much
simpler operation, as compared with prior art processes.
Moreover, because of the ragular el~mination of sulfonic
i groups, the carbon materials produced thereby have
good ho geneity and high activity and, therefore,
are of great industrial value.
The process of the present invention will be
~oru specifically explained wlth reference to the
follo~ing ex~nples.
~xa~ple 1
_ 20 1,280 g of naphthalene having a purity of
9S~ ~as mixed with 1,050 g of 98% sulfuric acid and
sulfonated at ~60C for 2 hours. Unreacted naphthalene
and the water formed by the reaction were removed from
the system by distillation under reduced pressure.
Then, 857 g of 35~ fonnalin was added and the resulting `
m~xture ~as reacted at 105C for 5 hours to obtain a - `
l 32446q
- 18 -
methylene-linked condensation product of naphthalene-
~-sulfonic acid. Furthermore, this condensation product
was neutraliæed with aqueous ammonia and then filtered
through No. 5 filter paper Imanufactured by Toyoroshi
Kaisha, Ltd.). The filtrate was concentrated to obtain
a spinning material in the form of a solution containing
34% by weight of water and having a viscosity of 100
centipoises at 85C. The~resulting salt of the conden-
sation product had a number-average molecular weight
of 4,300. This spinning material was dry-spun using
a stainle~s steel spinneret having an orifice diameter
of 0.1 mm.
The spun fiber was directly subjected to a
carbonization step~ Specifically, the fiber was fired
in a stream of N2 by raising the temperature from room
temperature to 800C at a ratè of 10C/min. The ;
resulting carbon ~iber had a diameter of 12 ~m, a
tensile strength of 65 kg/mm2, a specific surface area ;
of 250 m2/g a~ measured by thè C02 BET me~hod, and a
specific surface area o~ 30 m2/g as measured by the N2
BET method. Moreover, when measured at 25C under 3
atmospheres, its equilibrium C02 adsorption was 188 ml/g
and its equilibrium N~ adsorption was 25 ml/g.
Furthermore, the above fiber was activated
by treatment with steam at 850C for 60 minutes. The
resulting fiber had a specific surface area of },470 m2/g ~ ``
~ ',~~ '
.''. ' ~
.~
1 324469
-- 19 --
as measured by the CO2 BET method, and a specific sur-
face area of 1,560 m2/g as measured by the N2 BET
method.
5 Example 2
;` 1,700 g of creosote oil was mixed with 1,050 g
of 98% sulfuric acid and`sulfonated at 160C for 2
hours. Unreacted oil and~the water formed by the
reaction were removed from the sys~em by distillation.
Then, 857 g of a 35% aqueous solution of formalin was
added and the resulting mixture was reacted at 105C for
5 hours to obtain a methylene-linked condensation
product of aromatic sulfonic acids. This condensation
product was mixed with 37 g of calcium hydroxide to
convert the excess sulfuric acid to gypsum, and then
centrifuged to re~ove it together with water-insoluble
gel-like solid matter. ~fter centrifugation, the
supernatant liquid was adjusted to a water content
of 40~ by weight. Thus, spinning material A was 20 obtained in the form of a solution having a viscosity
of 100 centipoises at 85C. On the other hand, spinning
material B was prepared by taking a part of spinning
solution A, neutralizing it with sodium hydroxide,
purifying it again by filtration, and then adjusting
the filtrate to a water content of 40% by weight. Spinning
material A was spun using a platinum spinneret. The
spun fiber was directly subjected to a carbonization
1 32446q
- 20 -
step where it was fired in a stream of N2 by raising
the temperature from room temperature to 1,200C at a
rate of 10C/min. The resulting carbon fiber had a
diameter of 15 ~m and a tensile strength of 52 kg/mm2.
spinning material B was spun using a stainless steel
spinneret. The spun fiber was directly subiected to a
carbonization step where it was fired in a stream of
N2 by raising the temperature from room temperature
to 800C at a rate of 10C/min and then to an activation
s~ep by steam at a tempera~ure of 900C for 15 minutes. , -
The resulting carbon fiber had a diameter of 12 ~m, a ,
i~ tensile strength of 30 kgfmm2, a specific surface ~'`
area of 720 m2~g as measured by the C02 BET method,
and a specific surface area of 870 m /g as measured
15 by the N2 BET method. ~ ,
.
Example 3
1,280 g of naphthalene having a purity of 95% ~`
~as mixed ~ith 1,050 g of 983~ sulfuric acid and
_ 20 sulfonated at 158C for 1 hour. Unreacted naphthalene
and the water formed by the reaction were removed from
~he system by distàllation under reduced pressure. ,~
Howe3ver, 0.6% (based,on the charged amount~ of unreactëd
naphthal3ene remained in the system. Then, 875 g of ' '''
25 35~ formalin was added and the resulting mixture was ' ,- '
reacted at 105C for 5 'hours to obtain a methylene-linked ; ' ,
, , - , .. , : . . . ... . ~
1 324469
condensation product of naphthalene-B-sulfonic acid
This condensation product had a number-average molecular
weight of 3 200 Furthermore the condensation product
was neutralized with ammonia and then filtered
through No SC filter paper (manufactured by Toyoroshi
Raisha Ltd ) To the filtrate ~as add~d a specified
amount of an aqueous solution of Poval PVA-217~ (manu-
f~ctured by ~uraray Co ~Ltd ; polymerization degree
1 700-2,~00) Th~ filtr~te containing the ~ater-
~olubl~ polym~ric compound ~a~ conc~ntr~ted to obtain
a ~pinning matarial having a vi~co~ity of 20 poi~e~
i~ a~ ~a~ur~d at 85'C wit~ a Brookfi-ld typ~ vi~co~ ter
T~ pinn~ng ~at~rial ~ dry-~pun at bout 60 C u~ing
a ~tainlar~ ~t~ l ~pinn~ret having an ori~ica diametar
of 0 2 no S~a ~pun f~ r ~nr dircctly ~ub~c~d to
c rbo ~ ~tlo~l ~t p. ~cifical.ly, th~ fib-r ~ ~
pl ~ d ~ tr~n of N2 ~nd h ae ~ fro~ ro ~ t~pera-
t~r~ t ~i r~t of 200-C~A on the av~r~ge
D~r~ t ~ tioni procc-~, t~ fib r ~ held
_ 20 ~t ~ C ~ ~ ~nut~ and at l,OOO-C for S minute~
Th pi~ t~ Of ~pinning m~it ri~l~ contain~ng
variouJ ~ount of ~VA and ~o~e prop rti-- of th-
carbon f~bor~ fo`~ di fro~ ~he~- pinning mat ri~ are
~boNn iA Tablc 1
.~,,~ ~.
.
1 324469
-- 22 --
0~^ __ O ~ ~
~ .~ .,1 ~ P.
S~ ~ ~ a
tJ~ 1: ~ Cl~ ~ ~ ~ ~ t`~ _I N O N U~
O
~I) .q x ~ a~
_ ~ Q O Q~ 3 ~:
s~ ~
o~q ~` ~ ~
_ co ~ ~ ~ ~ .~
3 ~iP 3
t:~ ~ 1~ t~
~` g -, ,~
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0~ O O O O O O O O O O ~ U ~ `rI
~-1 ~ O ~1 ~D O ~ r ~ o .C
E~ ~ ~ ~ O
~ ~ ~ - ~ ~ o~ :
~-- ~ ~ u ~
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- ~o ~ ~ ~ ~ ,p ,~,. .
. ~ ~s ~
O ~ ~ ~o ~ ~ r co o
~ O O O` O O ~ ~ a 3 ~
~ --
`~ ~
1 324469
The carbon fiber having a PVA content of 0.8%
was activated by treatment with steam at 850C for
60 minutes. The resulting fiber had a specific surface
area of 1,400 m /g as measured by the C02 BET method,
and a specific surface area of 1,520 m2/g as measured
by the N2 BET mèthod. .
Example 4 ~
2,000 q o~ creo~o~e oil wa~ mixed with
10 1,050 g of 98~ ~ulfuric acid and sulfonated at 158C
for 1 hour. unreacted oil and th~ ~at~r form~d by th
; r~act$on ~or~ romov~d fro~ th ~y~t~u ~y di~till~tion.
Then, 357 g Of a 35~ aqul~Ou~ ~olution of formal$n
~- add~d and the~r~ulting ~xture ~ reacted at 105C
for 5 bour~ to obta$n a ~a~hyl-na~ cd cond n~ation
product of ro~-tic ~u~fonic ~Cid~ iC~ b~d ~ nu~b~r
~v~rag~ nol~cular ~oig~t of 5600 Thl~ condan-ation
~ ~ ~it~ 37 g of calc~un ~ydroxld~ to
cc ~ud~ o ulfuric ~cid to gy~-u~, and tbcn
_ 20 ~ r no~a ny i~ olubl~ ol~d ~ tt r Tb~
filtr~t~ ~q~ ~ utr~ d ~ith ~-oon~ nd divid~d into
fiva ~qual p~rt~ To four of th -o part- ~ro ~dd~d
pocl~ d mo~nt~ of aqu ou- olutio~- of poly~tyr-n--
Jul~oo~c ~o~d Jodiu~ ~-lt (P8-100, ~anuf~ctur~d by
25 $o oh Co , Ltd s avar~g~ mol~cular ~ight 800,000-
1,200,000), polyacrylic acid 80dium salt (Aqualic MP-30~,
1 32446q
manufactured by Japan Catalytic Chemical Industry Co ,
Ltd ; average molecular weight 40,000), polyacrylamide
(Hopelon A-lo~, manufactured by Mitsui-Toatsu Chemicals
Inc.; average molecular weight 600,000-700,000) and
polye~hylene glycol tPEO-3, manufactured by Seitetsu
Xagaku Co , Ltd average~molecular weight 600,000-
1,100,000), re~pectively` T~ese liquid~ were filtered
again through No 5C fil~er paper (manufactured by
Toyoroshi Kai~ha, Ltd ) and then concan~rated to obt~in
five spinning material~ having a vi~co~ity of 100
poises a~ mea~ured at 65 C ~it~ a Broo~field typo
vi~comct r ~ch of th~s~ ~pinning mat-rlal~
dry-~pun u~ing a ~pinn~r~t h~v~ng an orific- dia~etor
of 0 2 m~ Tho ~pun fiber ~a~ directly ~ub~oct~d to
a c~rbcni~ation st p Specifically, thc fib~r
plac~d in a ~tr a~ of N2 nd ~a~t-d fro~ roo~ t ~p ra- `
turc ~o l,OOO'C at a rat~ o~ 200 CJ~n on th av-r~g- ` `
Dur~ tbl~ ation proc~-, tha f~b r ~a~ hcld
~t ~O~C ~or ~ n~nute~ and at l,OOO C for S minuta~
_ 20 ~b~ J;dnrabl~t~ of t~a five ~pinnlng ~at rial~ ~nd
~o~ prop~rt~ ~ of tha carbon fibar- form d fro~ tha~a
~pinning ~at rial- ~re ~ho~n ~n Tabla 2
:, '
;'
~
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1 324469
s CP
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