Note: Descriptions are shown in the official language in which they were submitted.
2~7~2~8
DESCRIPTION
COMPOSITE COMPOSITION HAVING HIGH TRANSPARENCY
AND PROCESS FOR PRODUCING SAME
Technical Field
This invention relates to composite compositions having high
transparency, rigidity, toughness and thermal resistance, and to
a process for producing the same.
Backqround Art
Acrylic resins are being used in glazing applications such as
windowpanes because of their high transparency. However, acrylic
resins inherently have low rigidity, hardness and thermal
resistance, and are hence less than satisfactory.
In an attempt to overcome this disadvantage, many
investigations have heretofore been made on the formation of
composite materials consisLing of acrylic resins and inorgan1c
substances. For example, there have been proposed a number of
methods in which a dispersion of a silica compound (formed by
polycondensation of an alkoxysilane) or colloidal silica in an
acrylic resin solution is used as a coating film for hardenin~
the surfaces of plastic substrates (see, for example, Japanese
Patent Laid-Open Nos. 11952/'7~ and 11989/'78).
However, when such a composite material~is coated on pl~stic
substrates, a coating film having high hardness and high wear
resistance is obtalned, but~no substantial improvement in
rigidity can be expected. Moreover, good transparency is
obtained at coating film thicknesses of the order of several tens
of microns, but a marked reduction in transparency results at
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greater coating film thicknesses.
On the other hand, it is described in J. Mater. Res., Vol. 4,
p. 1018 (1989) that a silica gel-polymethyl methacrylate compos-
ite material is obtained by impregnating porous silica gel having
a controlled pore diameter with methyl methacrylate and then
polymerizing the lat~er. However, this method has the disadvan-
tage that it involves troublesome steps and is not suitable for
industrial purposes and that it is di~ficult to subject the
resulting composite material to postworking.
Disclosure of the Invention
It is an object of the presen~ invention to provide an organic
polymer to which high rigidity and high thermal resistance have
been imparted without impairing the high transparency, high
toughness, low specific gravity and good workability inherently
possessed by acrylic resins.
According to the present invention, there is provided a com-
posite composition consistiny essentially of
(A) a silica polycondensate formed by hydrolysis and
polycondensation of one or more silane compounds of the
general formula
SiRlaR2b(oR3)C (I)
where Rl and R2 are hydrocarbon radicals of 1 to 10 carbon
atoms which may contain an ether linkage or ester linkage,
R3 is a hydrogen atom or a hydrocarbon radical of 1 to 10
carbon atoms, a and b are whole numbers of 0 to 3, and c is
egual to (4-a-b)~and represents a whole number of 1 to 4; and
(B) a polymer of a radical-polymerizable vinyl compound (B')
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composed chiefly of one or more monomers selected from the
group consisting of acrylic acid, methacrylic acid, acrylic
esters and methacrylic esters;
the components (A) and (B) being intermingled homogeneously.
Best Mode for Carryin~ Out the Invention
Since the composite compositions of the present invention form
a semi-interpenetrating network structure in which the silica
skeleton of a silica polycondensate (A) formed by hydrolysis and
polycondensation of an alkoxysilane compound and a polymer (B) of
a radical-polymerizable vinyl compound (B') are intermingled on a
molecular level, they have the very striking feature that they
exhibit very high rigidity, toughness and thermal resistance, as
well as high transparency.
The radical-polymerizable vinyl compound (B') used in the
present invention lS composed chiefly of one or more monomers
selected from the group consisting of acrylic acid, me~hacrylic
acid, acrylic esters and methacrylic esters. Useful acrylic or
methacrylic esters (hereinafter referred to briefly as
(meth)acrylic esters) include, for example, alkyl esters of
(meth)acrylic acid such as methyl (meth)acrylate, ethyl
(meth)acrylatel propyl (meth)acrylate, butyl (meth)acrylate and
2-ethylhexyl (meth)acrylate; and hydroxyl-containing alkyl esters
of (meth)acrylic acid such as 2-hydroxyethyl (meth)acrylate and
2-hydroxypropyl (meth)acrylate. In the radical-polymerizable
vinyl compound (B'), at least one monomer selected from these
(meth)acrylic acid and (meth)acrylic esters should preferably be
present in an amount of not less than 50% by weight and more
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preferably in an amount of not less than 70% by weight. Among
(meth)acrylic acid and (meth)acrylic esters, methacrylic esters
such as methyl methacrylate, ethyl methacrylate and 2-
hydroxyethyl methacrylate are preferred, and methyi methacrylate
and 2-hydroxyethyl methacrylate are especially preferred.
In the present invention, certain compounds other than
(meth)acrylic acid and (meth)acrylic esters may be used as compo-
nents of the radical-polymerizable vinyl compound (B'). They are
compounds which are copolymerizable with the above-described
(meth)acrylic esters and the like. Such compounds include, for
example, unsaturated carhoxylic acids such as maleic acid and
itaconic acid; acid anhydrides such as maleic anhydride and
itaconic anhydride; maleimide derivatives such as
N-phenylmaleimide, N-cyclohexylmaleimide and N-t-butylmaleimide;
nitrogen-containing monomers such as acrylamide, methacrylamide,
acrylonitrile, methacrylonitrile, diacetone acrylamide and
dimethylaminoethyl (meth)acrylate; epoxy-containing monomers such
as allyl glycidyl ether and glycidyl (meth)acrylate; aromatic
vinyl compounds such as styrene and a-methylstyrene; and
multifunctional monomers such as ethylene glycol
di(meth)acrylate, allyl (meth)acrylate, divinylbenzene and
trimethylolpropane tri(meth)acrylate. These compounds may be
used alone or in combination. In the radical-polymerizable vinyl
compound (B')j these compounds are preferably used in an amount
of not greater than 50% by weight~and more preferably in an
amount of not greater than~30% by welght.
Moreover, vinyl compounds having ln the molecule at least one
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group reactive with the silanol groups contained in ~he silica
polycondensate (A) (i.e., at least one functional group selected
from the class consisting of hydroxyl, carboxyl, halogenated
silyl and alkoxysilyl groups) function to furthex improve some
properties (such as rigidity, toughness and thermal resistance)
of the resulting composite composition. Accordingly, it is
preferable that such a vinyl compound be contained as a compon~nt
of the radical-polymerizable ~inyl compound (B').
Such vinyl compounds having a reactive group in the molecule
include, for example, 2-hydroxyethyl (meth)acryla-te,
2-hydroxypropyl (meth)acrylate, (meth)acrylic acid,
vinyltrichlorosilane, vinyltrimethoxysilane and
y-methacryloyloxypropyltrimethoxysîlane. Among these vinyl
compounds, 2-hydroxyethyl methacrylate, methacrylic acid,
vinyltrichlorosilane, vinyltrimethoxysilane and
~-methacryloyloxypropyltrimethoxysilane are especially
preferred.
The silica polycondensate (A) used in the present invention is
a product obtained by hydrolysis and polycondensation of one or
more silane compounds o~ the general formula
SiRlaR2b(oR3)C (I)
where Rl and R2 are hydrocarbon radicals of 1 to 10 carbon atoms
which may contain an ether linkage or ester linkage, R3 is a
hydrogen atom or a hydrocarbon radical of 1 to 10 carbon atoms, a
and b are whole num~ers of O to 3, and c is equal to (4-a-b) and ;~
represents a whole number of 1 to 4. During this reaction, most
of the oR3 gro~ps contained in the ~ilane compounds are
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hydrolyz~d, but some oR3 groups still remain on the outer
surfaces of the silica polycondensate (A). Therefore, the silica
polycondensate (A) dissolves in the radical-polymerizable vinyl
compound (B').
The silane compounds which are within the scope of the general
formula (I) and useful in the present inven~ion can be divided
into silane compounds (A-l) in which c has a value of 4, and
silane compounds (A-2) in which c has a value of 1 to 3. More
specifically, the silane compounds (A-l) are represented by the
general formula
Si(oR334 (II)
where R3 is as previously defined, and the silane compounds (A-2)
are represented by the general formula
SiRlaR2b(oR3)d (III)
where Rl, R2, R3, a and b are as previously defined, and d is
equal to (4-a-b) and represents a whole number of 1 to 3. In
thls case, lt is preferable to use 1 to 100 parts by weight, more
preferably 20 to 100 parts by weight, of a silane compound (A-l)
and 0 to 99 parts by weight, more preferably 0 to 80 parts by
weight, of a silane compound (A-2). If the silane compound (A-l)
is used in smaller amounts, it is difficult to obtain a composite
composition having high rigidity and high thermal resistance as
desired in the present invention, probably because the resulting
silica:polycondensate fails ~o produce a well-developed three-
dimensiona} network structure. Most preferably, the silane
compounds (A-1) and (A-2) are used in amounts of 50 to 100 parts
by weight and 0 to S0 parts by weight, respectively.
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The silane compounds (A-1) which can be used in the present
invention include, for example, tetramethoxysilane,
tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane,
tetra-n-butoxysilane, tetrahexyl orthosilicate, tetraoctyl
orthosilicate, tetraphenyl orthosilicate and tetrabenzyl
orthosilicate. These silane compounds (A-1) may be used alone or
in combination. Among them, tetramethoxysi.lane and
tetraethoxysilane are preferably used.
The silane compounds (A-2) which can be hydrolyzed and
polycondensed together with the silane compounds (A 1) include,
for example, methyltrimethoxysilane, methyltriethoxysilane,
ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxy-
silane, phenyltriethoxysilane, vinyltrimethoxysilane,
vinyItriethoxysilane, y-glycidoxypropyltrimethoxysilane,
y-methacryloyloxypropyltrimethoxysilane, acetoxyethyltriethoxy-
silane, dimethyldimethoxysilane, diphenyldimethoxysilane,
methylethyldiethoxysilane, methylphenyldimethoxysilane,
methoxyethyltriethoxysilane and trimethylmethoxysilane. These
silane compounds (A-2) may be used alone or in combination.
Among them, methyltrimethoxysilane, methyltriethoxysilane,
vinyltrimethoxysilane and y-methacryloyloxypropyl-
trimethoxysilane are preferably used. Especially where
vinyltrimethoxysilane and y-methacryloyloxypropyl-
trimethoxysilane are used, the resulting silica polycondensate
(A) itself has polymerizable vinyl groups, so that it
copolymerizes with the radical-polymerizable vinyl compound (B')
to form chemical bonds therebeeween. The6e chemical bonds serve !~
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to reinforce the interface be~ween the polymer (B) of the
radical-polymerizable vinyl compound and the silica
polycondensate (A), thus improving the properties of the
composite composition of the present invention.
In order to form the silica polycondensate (A) by hydrolysis
and polycondensation of a silane compound, the silane compound
may be used alone or in combination with a minor amount of a
component co-condensable therewith. Useful components co-
condensable with silane compounds include, for example, metallic
alkoxides, organic metallic salts and metallic chelates. Such
co-condensable components are preferably used in an amount of O
to 100 parts by weight, more preferably O to 50 parts by weight,
per 100 parts by weight of the silane compound.
Specific examples of such co-condensable metallic alkoxides,
organic metallic salts and metallic chelates include titanium
tetraethoxide, titanium tetraisopropoxide, zirconium
tetraethoxide, zirconium tetra-n-butoxide, aluminum
triisopropoxide, zinc acetylacetonate, lead acetate and barium
oxalate.
In the hydrolysis and polycondensation reaction of a silane
compound, water needs to be present in the reaction system.
Generally, the proportion of water present in the reaction system
exerts no significant influence on the reaction rate. However,
if the amount of water is extremely small, the hydrolysis is too
slow to form a polycondensate. If the reaction is carried out
by using water in an amount of greater than 50% by weight based
on the total weight of the reaction system, the resulting silica
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polycondensate (A) solution is unstable and liable to premature
gelation, so that the radical-polymerizable vinyl compound (B')
canno-t be easily charged thereinto later. More preferably, water
is used in an amount of not ~reater than 20% by weight.
In the hydrolysis reaction of a silane compound, an inorganic
or organic acid can be used as a catalyst. Useful inorganic
acids include, for example, hydrohalogenic acids (such as
hydrochloric acid, hydrofluoric acid and hydrobromic acid),
sulfuric acid, nitric acid and phosphoric acid. Useful organic
acids include, for example, formic acid, acetic acid, oxalic
acid, acrylic acid and methacrylic acid.
This ca~alyst can be used in an amount of 0.001 to 10 parts by
weight per 100 parts by weight of the silane compound, though the
amount of catalyst used depends on the strength of the acid. If
the amount of catalyst used is less than 0.001 part by weight,
the silane compound is not fully hydrolyzed and, therefore, the
desired polycondensate may not be obtained. If the amoun~ of
catalyst used is greater than 10 part~ by weight, no additional
benefit is derived.
In order to effect the reaction mildly and uniformly, a
solvent is used in the reaction system ~or the hydrolysis of a
silane compound. It lS desirable that the solvent allows the
reactant (i.e., silane alkoxide), water and the catalyst to be
intermixed. Useful sol~ents include, for example, waterl
alcohols such as methyl alcohol, ethyl aIcohol and isopropyl
alcohol; ketones such as acetone; and ethers such as
tetrahydrofuran and dioxane.
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No particular limitation is placed on the amount of solvent
used, so long as the reactant can be dissolved homogeneously.
~owever, if the concentration of the reactant is too low, the
reaction rate may become unduly slow. The hydrolysis and
polycondensation reaction of a silane compound is usually carried
out at a temperature ranging from room temperature to 120 C for a
period of 30 minutes to 24 hours, and preferably at a temperature
ranging from room temperature to the boiling point of the solvent
for a period of 1 to 10 hours. It is important that, even after
completion of the reaction, the formed silica polycondensate is
left dissolved in the solvent. If the polycondensation is
allowed to proceed until the silica polycondensate separates out
as a solid from the solvent, or the solvent is distilled off, the
silica polycondensate (A) cannot be dissolved in the radical-
polymerizable vinyl compound (B') at ~he time of subsequent
polymerization, so that the silica polycondensate (A) and the
polymer (B) of the radical-polymerizable vinyl compound (s~) are
not homogeneously intermingled on a molecular level. Thus, it is
difficult to obtain a composite composition having excellent
properties as desired in the present invention.
In the silica polycondensate (A) obtained in the above-
described mlnner, there may be used a silica polycondensate whose
silanolic hydroxyl groups and/or alkoxy groups have been replaced
by a vinyl compound (C-l) having a hydroxyl compound or a vinyl
compound (C-2) having a carboxyl group. These vinyl compounds
(C-l) and (C-2) wlll herelnafter be referred to collectlvely as
modifying compounds.
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No particular limitation is placed on the type of modifying
compound used, so long as the modifying compound can replace the
silanolic hydroxyl groups and/or alkoxy groups of the silane
polycondensate (A) by means of its hydroxyl or carboxyl group.
Specific examples of the vinyl compound (C--l) having a
hydroxyl group include allyl alcohol, methallyl alcohol, 2-
hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.
Specific examples of the ~inyl compound (C-2) having a carboxyl
group include tmeth)acrylic acid, crotonic acid, itaconic acid
and maleic anhydride. The foregoing vinyl compounds (C-l) and
(C-2) may be used alone or in combination.
In order to replace the silanolic hydroxyl groups and/or
alkoxy groups of the silica polycondensate (A) by a modifying
compound, it is a con~on practice to add the modifying compound
to the reaction solution which has gone through the hydrolysis
and polycondensation reaction and hence contains the silica
polycondensate (A). The replacement reaction is usually carried
out at a temperature ranging from room temperature to 120-C for a
period of 30 minutes to 24 hours, and preferably at a temperature
ranging from room temperature to the boiling point of the solvent
for a period of 1 to 10 hours.
The modlfying compound may be added in excess to the reaction
system. If the modifying compound is added in excess, the
replacement reaction proceeds smoothly. Even if somé unreacted
modifying compound remains in the silica polycondensate tA)
solution and cannot be removed at the time of distilling off of
the solvent, such unreacted modifying compound copolymerizes with
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the radical-polymerizable vinyl compound (s~) and henc~ exerts no
adverse influence on the properties of the composite composition
of the present invention.
The modifying compound introduced into the silica
polycondensate (A) in the above-described manner has the effect
of improving the bonding properties of the interface between the
inorganic polymer (i.e., the silica polycondensate tA)) and the
organic polymer (i.e., the polymex of the compound (B')). During
subsequent polymerization for the formation of a composite
composition, the silica polycondensate (A) undergoes further
hydrolysis and polycondensation to produce a higher degree of
three~dimensional network structure. On this occasion, the
decomposition products arising from the modifying compound are
incorporated into the polymer derived from the radical-
polymerizable vinyl compound (B'), instead of providing volatile
components. Accordingly, use of the modifying compound has the
advantage that the resulting composite composition does not
suffer from volume shrinkage, cracking, fracture or other defect
which is caused by volatilization of the alcohol formed as a by-
product during further polycondensation of the silica
polycondensate (A), thus making it possible to produce
substantially thick articles successfully.
If a silica polycondensate (A) is formed by using only a vinyl
compound-substi~uted silane alkoxide resulting from reaction with
the above-described modifying compound, as the silane compound
being a monomer for the polycondensation reaction, the silica
content of the resulting fiilica polycondensate is about 14~ by
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weight at the best. However, if a silica polycondensate (A) is
first formed from a silane compound represented by the general
formula (I) and used after having been subjected ~o replacement
reaction with the modifying compound, the silica content of the
resulting composite composition can be increased to 15% by weight
or greater and further to 20% by weight or greater. Thus, there
can be produced composite compositions having a high silica
content.
The composite compositions of the present invention comprise a
silica polycondensate (A) and a polymer ~B) of a radical-
polymerizable vinyl compound (B'), both components being
intermingled on a molecular level. The proportions of the silica
polycondensate (A) and the polymer (B) of the radical-
polymerizable vinyl compound (B') in the composite compositions
are preferably chosen so that the components (A) and (B) are
present in amounts of 1 to 99% by weight and 99 to 1% by weight
respectively. More preferably, the components (A) and (B) are
used in amounts of 10 to 90~ by weight and 90 to 10% by weight,
respectively. Most preferably, the components (A) and (B) are
used in amounts of 70 to 20% by weight and 30 to 80% hy weight,
respectively. Especially when the silica polycondensate (A) is
used in an amount of 70 to 20% by weight, the properties desired
in the present invention are manifested to a full degree.
Although no partîcular limitation i9 placed on the method by
which the composite compositions of the present invention are
produced, i~ is preferable to produce them according to the
conventionally kno~n cast polymerization process. By way of
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example, the cast polymerization process starts with mixing a
silica polycondensate (A) with a radical-polymerizable vinyl
compound (B') in the form of a monomer or a partial pol~ner. The
solvent and water remaining in this mixture are distilled off to
obtain a mixed solution comprising the component ~A) dissolved in
the component (s~. Then, a casting material is prepared by
adding a radical polymeriæation initiator to the mixed solution.
More specifically, both components are mixed, for example, by
mixing the component (B') directly with a solution of the silica
polycondensate (A) in a suitable solvent and then removing the
solvent and water associated with the component (A), or by adding
the component (B') to a solution of the silica polycondensate
while removing therefrom the solvent and water associated with
the component (A). In other words, it is important that a mixed
solution comprising both components is prepared without causing
the component (A) to separate out as a solid. It is to be
understood that the above-described mixed solution can have any
ViScoSlty, so long as the component (A) is homogeneously
dLssolved ln the component (B'). For example, the mixed solution
may have the form of a gel-like material.
The radical polymerization initiators which can be used for
this purpose include, for example, azo compounds such as 2,2'-
azobisisobutyronitrlle,~2,2'-azobis(2,4-dimethylvaleronitrile)
and 2,2'~-azobis(2 r 4-dimethyl-4-methoxyvaleronitrile); organic
peroxides such as benzoyl peroxide and lauroyl peroxide; and
redox polymerization initiators.
This castiny material can be cast-polymerized by the so-called
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cell casting process in which a cell is formed by ~wo surface-
treated inorganic glass or metal plates disposed in opposed
relationship and sealed with a gasket at their periphery, and the
casting material is poured into the cell and heated; or the
continuous casting process in which a casting space is defined by
two stainless steel endless belts having one mirror-polished
surface and traveling in the same direction at the same speed,
and two gaskets disposed along the edges of the belts, and the
above-described casting material is continuously poured into the
casting space from the upstream side and heated. The
polymerization temperature at which a composite composition in
accordance with the present invention is formed is usually within
the range of 10 to lSO C. However, it is preferable to form a
composite composition by effecting polymerization of the
radical-polymerizable vinyl compound (B~) and further
polycondensatlon of the silica polycondensate (A)~concurrently at
a temperature above room temperature, i.e., within the range of
40 to 150-C.
Furthermore, in any convenient step of the present process,
various additives such as colorants, ultraviolet absorbers,
thermal stabilizers and mold releaslng agents may be added to the
composite composition in such amounts as not to impair the
effects of the present invention.
Even when the SiO2 content is 15% by weight or greater, the
composite compositions of the present invention have a haze of
not greater ~han 5% or, in most cases, not greater than 3~ as
measured at a plate thickness of 3 mm. ~This is one of the most
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striking features of the present invention. In electron
micrographs, no fine particle of silica is observed even a-t a
magni~ication of 200,000 diameters. This means that, in the
composite compositions of the present invention, the silica
polycondensate (A) and the polymer (B) of the radical-
polymerizable vinyl compound (B') are intermingled on a molecular
level. In the case of acrylic resins having ordinary fine
particles of silica dispersed therein, the fine particles of
silica are clearly recognized in electron micrographs at a
magnification of the order of several thousand diameters. When
the SiO2 content is 15% by weight or greater, such composite
materials have a haze of greater than 20% as measured at a plate
thickness of 3 mm and show a marked reduction in transparency.
It can be seen from the foregoing description that, as contrasted
with acrylic resins having ordinary fine particles of silica
dispersed therein, the composite compositions o the present
invention have surprising effects which have not been known in
the prior art.
The present invention is more specifically explained with
reference to the following examples. However, it is to be
understood that the present invention is not limited thereto. In
these examples and comparative examples, all parts are by weight
unless otherwise stated.
Properties of the resulting composite compositions were
evaluated according to the following methods: Transparency was
evaluated by using an integrating sphere type haze meter
(SEP-H-SS; manufactured by Japan Precision Optics Co., Ltd.) to
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measure the total light transmittancP and haze of a sample
according to ASTM D1003. Thermal resistance was evaluated by
annealing a sample and then measuring its heat distortion
temperature (HDT) according to ASTM D648. Strength was evaluated
by annealing a sample at 130C for 60 hours and then making a
bendin~ test of the sample according to ASTM D790 to determine
its flexural breaking strength and flexural modulus of
elasticity. The SiO2 content of a sample was determined by
calcining the sample in a crucible and calculating its SiO2
content from the weighk of the residue.
Example 1
A glass flask fitted with agitating blades was charged with
832 parts of tetraethoxysilane and 800 parts of ethanol. While
the contents of the flask were being stirred, 144 parts of
deionized water and 4 parts of 36 wt.% hydrochloric acid were
added ~hereto and the temperature was xaised to 70 C.
After 2 hours, the volatile components (i.~e., the solvent and
~water) were dlstilled off at 40 C under reduced pressure by means
of~a rotary e~aporator, while methyl methacrylate (hereinafter
abbrevlated as MMA) was added at the same rate as the volatile
components were distilled off. Finally, the solvent was
completely replaced by MMA and the resulting mixture was
concentrated to a total amount of 800 parts. Thus, there was
obtained a mlxed solution.
Then, 0.1 part of 2,2'-azobisisobutyronitrile (hereinafter
,
~abbrevi~ated as AIBN) as a polymerization initiator was added to
and dissolved in 200 parts of the above mix~d solution. After
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the mixed solution was exposed to reduced pressure in order -to
remove any dissolved air, it was poured into a cell formed by a
gasket and two stainless steel plates and adjus~ed previously so
as to have a thickness of 3 mm. Subsequently, ~he mixed solution
was polymerized at 80 C for 5 hours and then at 120C for 2 hours
to obtain a cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 1.
Example 2
A glass flask fitted with agitating blades was charged with
832 parts of tetraethoxysilane and 800 parts of ethanol. While
the contents of the flask were being stirred, 144 parts of
deionized water and 4 parts of 36 wt.% hydrochloric acid were
added thereto and the temperature was raised to 70 C. After 2
hours, 450 parts by weight of 2-hydroxyeth~l methacrylate
(hereinafter abbreviated as HEMA) was added. The volatile
components (i.e., the solvent and water) were distilled off in
the same manner as described in Example 1, while MMA was added
until the solvent was completely replaced by MMA. The resulting
mixture was concentrated to a total amount of 1,100 parts. Thus,
there was obtained a mixed solution.
Then, 0.1 part of AIsN was added to and dissolved in 300 parts
of the above mixed solution. Thereafter, the mixed solution was
polymerized in all thè same manner as described in Example 1 to
obtain a cast plate. Properties of this cast plate were
evaluated and the results thus obtalned are shown in Table 1.
Example 3
A glass flask fitted with agitating blades was charged with
. .
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~: : ' ' '' ' ' , . ~ .
:~ ' ,- . ~ ' : ' ,
. .
- lg - 2~ 2~
832 par~s of tetraethoxysilane, 80 parts of y-methacryloyloxy-
propyltrimethoxysilane and 800 parts o~ ethanol. While the
contents of the flask were being stirred, 160 parts of deionized
water and 4 parts of 36 wt.% hydrochloric acid were added thereto
and the tempera-ture was raised to 70 C. After 2 hours, the
solvent was completely replaced by MMA in the same manner as
described in Example 1, and the resulting mixture was
concentrated to a total amount of 800 parts. Thus, there was
obtained a mixed solution.
Then, 0.1 part of AIBN was added to and dissolved in 200 parts
of the above mixed solution. Thereafter, the mix~d solution was
polymerized in all the same manner as described in Example 1 to
obtain a cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 1.
Example 4
A glass flask fltted with agitating blades was charged with
832 parts of tetraethoxysilane and 800 parts of ethanol. While
the contents of the fz Pb were being stirred, 144 parts of
deionlzed water and 4 parts of 36 wt.~ hydrochloric acid were
addbQ thereto and the temperature was raised to 70 C. After 2
hours, 600 parts of HEMA was added and the volatile components
were completely distilled off by means of a vacuum pump. Thus,
there was obtained 8;84 parts of a mixed solution of a silica
polycondensate in HEMA.
::
Then, 0.1 part of AIBN was added to and dissolved in 200~parts
of the above mixed solution. Thereafter, the mixed solution was
polymarized ln~all the same manner as descrlbed in~Example 1 Co
:
.
. : ~
- 20 -
ohtain a cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 1.
Example 5
A glass flask fitted with agitating blades was charged with
416 parts of tetraethoxysilane, 356 parts of methyltriethoxy-
silane and 800 parts of ethanol. While the contents of the flask
were being stirred, 144 parts of deionized water and 4 parts of
36 wt.% hydrochloric acid were added thereto and the temperature
was raised to 70 C. After 2 hours, the solvent was completely
replaced by MMA in the same manner as described in Example 1, and
the resulting mixture was concentrated to a total amount of 600
parts. Thus, there was obtained a mixed solution.
Then, 0.05 part of 2,2-azobis(2,4-dimethylvaleronitrile)
(hereinafter abbreviated as AVN) was added to and dissolved in
200 parts of the above mixed solution. Thereafter, the mixed
solution was polymerized in all the same manner as described in
Example 1 to obtain a cast plate. Properties of this cast plate
were evaluated and the results thus obtained are shown in Table
1. :
Example 6
A glass flask fitted with agitating blades was charged with
396 parts of tetraethoxysilane, 24.8 parts of y-methacryIoyloxy~ ;
propyltrimethoxysilane and 400 parts of ethanol. While the
contents of the flask were being stirred, 72 parts of deioni~ed
; water and 2 parts of 36 wt~% hydrochloric acid were added thereto
and the temperature was raised to 70 C. After 2 hours, the
reaction solutLon was cooled and 0.05~part of AVN was added
- -:
:,;
. . .
,.
: . :
- 21 - 2~ ~1 208
thereto. Then, the solvent was completely replaced by MMA in the
same manner as described in Example l, and the resulting mixture
was concentrated to a total amount of 200 parts. Thus, there was
obtained a mixed solution.
The resulting soft, transparent gel-like material was placed
in a cell formed by a gasket and two stainless steel plates and
adjusted previously so as to have a thickness of 3 mm.
Subsequently, the gel-like material was polymerized at 65C for 4
hours and then at 130C for 2 hours to obtain a cast plate.
Properties of this cast plate were evaluated and the results thus
obtained are shown in Table l.
Example 7
A glass flask fitted with agitatinq blades was charged with
832 parts of tetraethoxysilane and 800 parts of ethanol. While
the contents of the flask were being stirred, 144 parts of
deionized water and 4 parts of 36 wt.% hydrochloric acid were
added thereto and the temperature was raised to 70 C. After 2
hours, the reaction solution was cooled to O C and slowly added
dropwise to a stirred solution which had been prepared by
dissolving 80 parts of titanium tetralsopropoxide in 800 parts of
ethanol and had baen cooled to O C. Thereafter, the solvent was
completely replaced by MMA in the same manner as described in
Example 1, and the resulting mixture was concentrated to a total
amount of 800 parts. ~hus, there was obtained a mixed solution.
Then, 0.1 part of AIBN was added to and dissolved in 200 parts
of the above mixed solukion. Thereafter, the mixed solution was
polymerized in all the same manner as described in Example 1 to
- ' "
, '
- 22 - ~071?. 08
obtain a cast plate. Properties of ~his cast plate were
evaluated and the results thus obtained are shown in Table 1.
Example_8
A glass flask fitted with agitating blades was charged with
792 parts of tetraetho~ysilane, 50 parts of y-methacryloyloxy-
propyltrimethoxysilane and 800 parts of ethanol. While the
contents of the flask were being stirred, 144 parts of deionized
water and 4 parts of 36 wt.% hydrochloric acid were added thereto
and the temperature was raised to 70 C. After 2 hours, 400 parts
of a partial polymer of MMA (having a polymerization rate of 10%
by weight) was added thereto. Then, the solvent was completely
replaced by MMA in the same manner as described in Example l, and
the resulting mixture was concentrated to a total amount of l,lO0
parts. Thus, there was obtained a mixed solution.
Then, 0.1 part of AIBN was added to and dissolved in 200 parts
of the above mixed solution. Thereafter, the mixed solution was
poly:merized in all the same manner as described in Example l to
obtain a cast plate. Properties of this cast plate were
evaluated and the xesults thus obtained are shown in Table l.
Rxample 9
A glass flask fitted with agitating blades was charged with
832 parts of tetraethoxysilane and 800 parts of ethanol. While
the contents of ~he flask were being stirred, 144 parts of
deionized water and 4 parts of 36 wt.% hydrochloric acid were
added thereto and the temperature was raised to 70 C. ~fter 2
hours, 80 parts of methacrylic acid (hereinafter abbreviated as
MAA) was added thereto. Then, MMA was added in the same manner
:
. ," . : . , ' ,' . ' ' ,, :,,, ': :, ' , :
- 23 - ~ ~7~
as described in Example 1 to replace the solvent by MAA and MMA,
and the resulting mixture was concentrat2d to a total amount of
800 parts. Thus, there was obtained a mixed solution.
Then, 0.1 part of AIBN was added to and dissolved in 200 parts
of the above mixed solution. Thereafter, the mixed solution was
polymerized in all the same mannex as described in Example 1 to
obtain a cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 1.
Example 10
A glass flasX fitted with agitating blades was charged with
832 parts of tetraethoxysilane, 6.5 parts of vinyltrichlorosilane
and 800 parts of ethanol. While the contents of the flask were
being stirred, 144 parts of deionized water was added thereto and
the temperature was raised to 70 C. After 2 hours, the solvant
was completely replaced by MMA in the same manner as described in
Example 1, and the resulting mixture was concentrated to a total
amount of 800 parts. Thus, there was obtained a mixed solution.
Then, 0.1 part of AIBN was added to and dissolved in 200 parts
of the above mixed solution. Thereafter, the mixed solution was
polymerized in all the same manner as~ described in Example 1 to
obtain a cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 1.
Exampl_ 11
A cast plate was obtained in all the same mann~r as descrlbed
in Example 1, except that 832 parts of tetraethoxy-silane was
replaced by 608 parts of tetramethoxysilane. Properties of this
cast plate were evaluated and the results thus obtained are shown
:
:. :: ,,
:- : . : : . : - :
.
:, , : ~ ::, : .
~: : . ~,. .. - : ~ - : .
- 24 - 2B7~.2~
in Table 1.
Example 12
A cast plate was obtained in all the same manner as described
in Example 3, except that 80 parts of y-methacrylyoloxypropyl-
trimethoxysilane was replaced by 59 parts of vinyltrimethoxy-
silane. Properties of this cast plate were evaluated and the
results thus obtained are shown in Table 1.
Example 13
A cast plate was obtained in all ~he same manner as described
in Example 3, except that the amount of water used for the
reaction was altered to 288 parts. Properties of this cast plate
were evaluated and the results thus obtained are shown in Table
1.
Example 14
A cast plate was obtained in all the same manner as described
in Example 4, except that the amount of water used ~or the
reaction was altered to 1,440 parts. Properties of this cast
plate were evaluated and the results thus obtained are shown in
Table 1.
Comparative Examp~e 1
O.1 part of AIBN was dissolved in 100 parts of MMA. This
mixture was polymerized in the same manner as described in
Example 1 to obtain a cast plate. Properties of this cast plate
wsre evaluated and the results thus obtained are shown in Table
1. ~'
Comparative Example 2
While 80 part of MMA was being stirred/ 20 parts of finely
:, , ~,~
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: . , , ,. : : : .: . ' ,:
- 25 ~ Q~
powdered silica (Aerosil R-972; trade name; manufactured by Japan
Aerosil Co., Ltd.) having an average particle diameter of 16 nm
was added thereto and uniformly dispersed therein to obtain a
dispersion of finely powder silica. When finely powdered silica
was added in greater amounts, the resulting dispersion showed a
marked increase in viscosity and could not be subjected to
subsequent operations.
Then, 0.1 part. of AIBN was added to and dissolved in 100 parts
of the above dispersion of finely powdered silica. This
dispersion was polymerized in all the same manner as described in
Example 1 to obtain a cast plate. Properties of this cast plate
were evaluated and the results thus obtained are shown in Table
1.
Comparative Example 3
A cast plate was obtained in all the same manner as described
in Example 1, except that 832 parts of tetraethoxysilane was
replaced by 712 parts of methyltrlethoxysilane. Properties of
this cast plate were evaluated and the results thus obtained are
shown in Table 1.
::
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.
.
. ~ . . . .
.
' . : . . '
:, ~
- 26 - ~ ~7~'0~
Table 1
r ~ r --
Total l l I Flexural I Flexural
Example I light I Ha7e I HDT j breaking I modulus ¦ SiO2
¦ No. ¦ trans- ¦ I ¦ strcngth ¦ of elas- ¦ content ¦
I I mittance I l l I ticit~
I I (Z) I (1) I ('C) I (kg/cm2) 1 (kg/cm ) I (wt.Z)
Example 1 193.4 ¦ 1-7 1 127 1800 14.0x104 1 29.7
- I
I n 2 ¦93.1 ¦ 1.5 ¦ 120 ¦1,200 ¦3.8x104 ¦ 21.7
" 3 192.6 1 1.8 1 125 11,100 14.0x104 1 26.1
" 4 193.3 1 1.7 1 120 11,000 14.1x104 1 26.8
" 5 192.1 1 1.9 1 140 1800 15.2x104 1 39.7
l_ l l l l ll l
" 6 192.0 1 2.2 1 172 1800 17.2x104 1 58.9
¦ 7 ¦91.6 ¦ 2.6 ¦ 131 ¦1,000 ¦4.3xlO ¦ Z8.8
¦ 8 ¦92.0 ¦ 2.5 ¦ 115 ¦1,100 ¦3.7xlO ¦ 21.0
4--1 1
I n 9 ¦92.0 ¦ 2.6 ¦ 135 ¦1,000 ¦4.3xlO ¦ 29.7
1-
I n 10 191 . 9 1 2-8 1 124 1I,000 14.0x104 1 29.5
¦ 11 ¦92.8 ¦ 1.8 ¦ 128 ¦800 ¦4.2xlO ¦ 29.&
" 12 192.0 1 2.0 1 124 11,000 14.0x104 1 29.2
~ l l I I ~
" 13 192.2 1 2.0 1 129 11,100 14.8x104 1 28.2
_
I n 14 ¦92.0 ¦ 2.2 ¦ 132 ¦1,000 ¦5.5x104 ¦ Z6.6
Comparative I l l ~ I ll ¦
Example 1 193.4 ¦0.4 ¦92 11 t 200 ¦3.0x104 1
4 l l '
I n 2¦ 75-5 ¦29.8 ¦ 109 ¦ 500 ¦ 4.4xlO ¦ 21.1
" 31 92.1 1 2.0 190 l 700 l 2.6x104 1 29.7
: ~ !
:
- 2~ 2 Q ~
Example 15
A glass flask fitted with agi-tating blades was charged with
832 parts of ~etraethoxysilane and 800 parts of ethanol. While
the contents of the flask were being stirred, 144 parts of
deionized water and 4 parts of 36 wt.% hydrochloric acid were
added thereto, the temperature was raised to 70C, and the
stirring was continued for 2 hours to form a silica
polycondensate. Then, 400 parts of HEMA was added and the
stirring was continued at 70 C for an additional 2 hours.
Thereafter, the volatile components were distilled off at 40 C
under reduced pressure by means of a rotary evaporator, and
further distilled of by means of a vacuum pump. Thus, there was
ob~ained 715 parts o~ a solution in HEMA of a silica
polycondensate having vinyl groups as a result of replacement by
HEMA.
Then, 0.2 part of AIBN was dissolved in a mixed solution
composed of 100 parts of the above solution of the silica
polycondensate in HEMA and 100 parts of MMA.` This mixed solution
was polymerized in all the same mannar as described in Example 1
to obtain a colorless, transparent cast plate. Properties of
this cast plate were e~aluated and the results thus obtained are
shown in Table 2.
ExampIe 16
A glass ~flask fitted with agitating blades was rharged with
8Q0 parts of a partia] polycondensate of tetraethoxysilane (Ethyl
Silicate 40~ trade name; manufaotured by Japan Colcoat Co.,
Led.), 400 parts of ethanol and 400 parts of HEMA. While the
: '
., : .
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'' ~ ' ' . ~ ' '
- 28 - 2~
contents of the flask ~ere being stirred, 144 par~s of deionized
water and 4 parts of 36 wt.~ hydrochloric acid were added
thereto, the ~emperature was raised to 70 C, and the stirring was
continued for 2 hours.
Thereafter, the volatile components were distilled off at 40 C
under reduced pressure by means of a rotary evaporator, and
further distilled off by means of a vacuum pump. Thus, there was
obtained 859 parts of a solution in HEMA of a silica
polycondensate having vinyl groups as a result of replacement by
HEMA.
Then, 0.2 part of AIBN was dissolved in a mixed solution
composed of 100 parts of the above solution of the silica
polycondensate in HEMA and 100 parts of MMA. This mixed solution
was polymerized in all the same manner as describqd in Example 1
to obtain a colorless, transparent cast plate. Properties of
this cast plate were evaluated and the results thus obtained are
shown in Table 2.
Example 17
A solution in HEMA of a silica polycondensate having vinyl
groups as a resu]t of replacement by HEMA was obtained in all the
same manner as dPscribed in Example 15. Then, 0.2 part of AIBN
was dissolved in a mixed solution composed of 150 parts of the
above solution of the silica polycondensate in HEMA and 50 parts
of MMA. This mixed solution was polymerized in all the same
manner as described in Example 1 to obtain a colorless,
transparent cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 2.
:
.~ ,.
: . - . . ;
~ L~
- 29 -
Example 18
A solution in HEMA of a silica polycondensate having vinyl
groups as a result of replacement by HEMA was obtained in all the
same manner as described in Example 15. Then, 0.2 part of AIBN
was dissolved in a mixed solution composed of 100 parts of the
above solution of the silica polycondensate in HEMA and 100 parts
of HEMA. This mixed solution was polymerized in all the same
manner as described in Example 1 to obtain a colorless,
transparent cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 2.
Example 19
A solution in HEMA of a silica polycondensate having vinyl
groups as a result of replacement by HEMA was obtained in all the
same manner as described in Example 15. Then, 0.2 part of AIBN
was dissolved in 200 parts of the above solution of the silica
polycondensate in HEMA. This solution was polymerized in all the
same manner as described in Example 1 to obta~n a colorless,
transparent cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 2.
Example 20
A glass flask fitted with agitating blades was charged with
832 parts of tetraethoxysilane and 800 parts of ethanol. While
the contents of the flask were being stirred, 144 parts of
deionized water and 4 parts of 36 wt.% hydrochloric acid were
added thereto, the temperature was raised to 70 C, and the
stirring was continued for 2 hours. Thereafter, khe reaction
solution was cooIed to O C and slowly added dropwise to a stirred
. . . ~,
. .
- ~: . - .. . .
. . . ~ . .
-.
. . . ..
. :
2 ~ ~
-- 30 --
solution which had been prepared by dissolving 80 parts of
titanium tetraisopropoxide in 800 parts of ethanol and had been
cooled to 0C. Then, 400 parts of HE~A was added thereto and the
stirring was continued at 70 C for an additional 2 hours.
Thereafter, the volatile components were distilled off at 40 C
under reduced pressure by means of a rotary evaporator, and
further distilled off by means of a vacuum pump. Thus, there was
obtained 672 parts of a solution in HEMA of a silica
polycondensate having vinyl groups as a resul~ of replacement by
HEMA.
Then, 0.2 part of AIBN was dissolved in a mixed solution
composed of 100 parts of the above solution of the silica
polycondensate in HEMA and 100 parts of MMA. This mixed solution
was polymerized in all the same manner as described in Example 1
to obtain a slightly yellowish cast plate. Properties of this
cast plate were evaluated and the results thus ob~ained are shown
in Table 2.
xample 21
709 parts:of a solution ln MAA of a silica polycondensate
havin~ vinyl groups as a result of replacement by MAA was
obtained in all the same manner as described in Example 15,
except that 400 par~s of MAA was used in place of 400 parts of
HEMA.
Then, 0.2 part of AIBN was dissolved in a mixed solution
composed of 100 parts of the above s~olution of the sllica
pol~condensate in MAA and 100 parts of MMA. l'his mixed solution ~ `
:
was polymerized ln all the same manner as described in Example 1
:
.
. . : : :. : :: ,
.:: ~ ~ .~ : .. :,
- 31 -
to obtain a colorless, transparent cast plate. Proper~ies of
this cast plate were evaluated and the results thus obtained are
shown in Table 2.
Example 22
851 parts of a solution in MAA of a silica polycondensate
having vinyl groups as a result of replacement by MAA was
obtained in all the same manner as described in Example 16,
except that 400 parts of M~A was used in place of 400 parts of
HEMA.
Then, 0.2 part of AIBN was dissolved in a mixed solution
composed of 100 parts of the above solution of the silica
polycondensate in MAA and 100 parts of MMA. This mixed solution
was polymerized in all the same manner as described in Example 1
to obtain a colorless, transparent cast plate. Properties of
this cast plate were evaluated and the results thus obtained are
shown in Table 2.
Example_23
A solution in MAA o~ a silica polycondensate having vinyl
groups as a result of replacement by MAA was obtained in all the
same manner as described in Example 21. Then, 0.2 part of AIBN
was dissolved in a mixed solution composed of 150 parts of the
above solution of the sillca polycondensate in MAA and 50 parts
of MMA. This mixed solution was polymeriz~ed ln all the same
manner as described in Example l to obtain a colorless,
transparent cast plate. Properties of this cast:plate were
evaluated and the results thus obtained are shown in Table 2.
.
'
2 i~ (~
- 32 ~
A solution in MAA of a silica polycondensate having vinyl
groups as a result of replacement by MAA was obtained in all the
same manner as described in Example 21. Then, 0.2 part of AIBN
was dissolved in a mixed solution composed of 100 parts of the
above solution of ~he silica polycondensate in MA~ and 100 par~s
of HEMA. This mixed solution was polymerized in all the same
manner as described in Example 1 to obtain a colorless,
transparent cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 2.
Example 25
A solution in MAA of a silica polycondensate having vinyl
groups as a result of replacement by MAA was obtained in all the
same manner as described in Example 21. Then, 0.2 part of AIBN
was dissolved in 200 parts of the above solution of the silica
polycondensate in MAA. This solution was polymerized in all the
same manner as described in Example 1 to obtain a colorless,
transparent cast plate. Properties of this cast plate were
evaluated and the results thus obtained are shown in Table 2.
Example 26
670 parts of a solution in MAA of a silica polycondensate
having vinyl groups as a result of ~eplacement by MAA was
obtained in all the same manner as described in Example 16,
except that 400 parts of MAA was used in place of 400 parts of
HEMA.
Then, 0.2 part of AIBN was dissolved in a mixed solution
,
composed of lOO parts of the above solution of the silica
polycondensate in MAA and 100 parts o~ MMA. This mixed solution
:
,. ` :
, :. .. -
,
; .: - :
' ` ' . ; ',
- 33 ~
was polymerized in all the same manner as described in Example 1
to obtain a slightly yellowish cast plate. Properties of this
cast plate were evaluated and the results thus obtained are shown
in Table 2.
:
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.
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- 34 -
Table 2
I ¦ Total l l ¦ Flexural ¦ Flexural ¦
Example ¦ light I Haze ¦ HDT I breaking ¦ modulus ¦ SiO2
No. I trans- I I I strength I of elas- I content
mittance I l l I ticit
(%) I (~) I (C) I (kg/cm2) 1 (kg/cm ) I (wt.~)
¦ Example 15 ¦ 93.1 ¦ 1.5 ¦120 ¦ 1,150 ¦ 3.8x104 ¦ 15.5
" 16 1 93.3 1 1.5 1 121 11,200 1 3.7x104 1 18.6
I l l l l ll I
I n 17 ¦ 93.0 ¦ 1.6 ¦ 124 ¦1,120 ~ 4.0xlO ¦ 24.2
I '` 18 1 93.1 1 1.7 1 120 11,200 1 3.7x104 1 15.7
4 I
I n 19 ¦ 93.0 ¦ 1.8 ¦ 128 ¦ 1,120 ¦ 4.1xlO ¦ 30.8
I n 20 ¦ 91.2 ¦ 1.9 ¦ 124 ¦ 1,200 ¦ 4.0xlO ¦ 21.7
4 I ~
I n 21 ¦ 92.2 ¦ 1.6 ¦ 124 ¦ 1,100 ¦ 3.8xlO ¦ 16.0
- - -----I 4 I
I n 22 ¦ 93.0 ¦ 1.7 ¦ 125 ¦ 1,200 ¦3.8xlO ¦ 18.7
,. I l l l l l l I
1 23 ¦ 92.9 ¦ 1.7 ¦ 125 ¦ l,lS0 ¦4.0xlO ¦ 24.5
¦ 24 ¦ 93.2 ¦ 1.6 ¦ 119 ¦ 1,200 ¦3.8xlO ¦ 16.0
, I I I 1 1 14 1 1
I n 25 ¦ 92.7 ¦ 1.9 ¦ 127 ¦ 1,120 ¦4.0xlO ¦ 31.0
" 26 1 91.0 1 1i8 1 1~6 1 1,200 1 4.1x104 1 21.9
:
.
- - - ~ : . :
2~7120~
Thus, the present invention provides composite compositions
having high transparency, thermal resistance, rigidi~y and
toughness. These composite compositions are useful in various
applications where inorganic glass has heretofore been used, such
as windowpanes for houses and vehicles.
:: :
