Polyether copolymer and crosslinked solid polymer electrolyte

A polyether copolymer having a weight-average molecular weight of 10.sup.4 to 10.sup.7, comprising 5 to 40% by mol of a repeating unit derived from epichlorohydrin, 95 to 60% by mol of a repeating unit derived from ethylene oxide, and 0.001 to 15% by mol of a crosslinkable repeating unit derived from a reactive oxirane compound, gives a provide a crosslinked solid polymer electrolyte which is superior in processability, moldability, mechanical strength, flexibility and heat resistance, and has markedly improved ionic conductivity.

FIELD OF THE INVENTION 
The present invention relates to a crosslinkable polyether copolymer, a 
crosslinked material of said copolymer, and a crosslinked solid polymer 
electrolyte. More particularly, the present invention relates to a 
crosslinked solid polymer electrolyte which is suitable as a material for 
electrochemical devices such as battery, capacitor, sensor, condenser and 
EC (electrochromic) device, and an antistatic agent for rubber and plastic 
materials. 
RELATED ART 
As an electrolyte constituting an electrochemical device such as a battery, 
a capacitor and a sensor, those in the form of a solution or a paste have 
hitherto been used in view of the ionic conductivity. However, the 
following problems are pointed out. That is, there is a fear of damage of 
an apparatus arising due to liquid leakage, and subminiaturization and 
thinning of the device are limited because a separator to be impregnated 
with an electrolyte solution is required. To the contrary, a solid 
electrolyte such as inorganic crystalline substance, inorganic glass and 
organic polymer substance is suggested. The organic polymer substance is 
generally superior in processability and moldability and the resultant 
solid electrolyte has good flexibility and bending processability and, 
furthermore, the design freedom of the device to be applied is high and, 
therefore, the development is expected. However, the organic polymer 
substance is inferior in ionic conductivity to other materials at present. 
For example, a trial of containing a specific alkaline metal salt in an 
epichlorohydrin rubber and applying the resultant to an ionic conductive 
solid electrolyte has already been suggested ("Effect of some factors on 
conductivities of polymer ionic conductors", Chen Li-quan et al., Wuli 
Xucb-ao, Vol. 36, No. 1, pages 60-66 (1987)), however, improved ionic 
conductivity has further required. A trial of containing a specific 
alkaline metal salt in a mixture of an epichlorohydrin rubber and a 
low-molecular weight polyethylene glycol derivative and applying the 
resultant to a solid polymer electrolyte has been suggested in Japanese 
Patent Kokai Publication No. 235957/1990 including the present applicant, 
however, those having more excellent mechanical characteristics and ionic 
conductivity have been required. In the case of widely applying a solid 
polymer electrolyte to devices, those having sufficient mechanical 
strength and flexibility are required to prevent electrical continuity and 
breakage of devices. 
SUMMARY OF THE INVENTION 
The present inventors have found that, when using a copolymer obtained by 
combining epichlorohydrin, ethylene oxide and a crosslinkable oxirane 
compound, there can be obtained a solid electrolyte, which is superior in 
ionic conductivity and does not cause plastic deformation or flow even 
under high temperature, by formulating an electrolyte salt compound before 
or after crosslinking. 
The present invention provides a polyether copolymer having a 
weight-average molecular weight of 10.sup.4 to 10.sup.7, comprising: 
(A) 4 to 40% by mol of a repeating unit derived from a monomer represented 
by the formula (I): 
##STR1## 
(B) 95 to 59% by mol of a repeating unit derived from a monomer 
represented by the formula (II): 
##STR2## 
and (C) 0.001 to 15% by mol of a repeating unit derived from a monomer 
represented by the formula (III-1) or (III-2): 
##STR3## 
wherein R.sup.1 and R.sup.2 represent a substituent containing an 
ethylenically unsaturated group, a substituent containing a reactive 
silicon group, or a substituent containing an epoxy group at the end, 
which is represented by the formula (IV): 
##STR4## 
wherein R.sup.3 is a divalent organic residue comprising at least one atom 
selected from carbon, oxygen and hydrogen atoms. 
The present invention also provides 
(1) a crosslinked material which is crosslinked by means of a reactivity of 
said copolymer, 
(2) a solid polymer electrolyte obtained by mixing said copolymer 
(uncrosslinked polymer) with an electrolyte salt compound, 
(3) a crosslinked solid polymer electrolyte comprising a crosslinked 
material of said copolymer obtained by utilizing a reactivity of said 
copolymer, and an electrolyte salt compound, and 
(4) a battery comprising said crosslinked solid polymer electrolyte. 
DETAILED DESCRIPTION OF THE INVENTION 
The copolyer of the present invention has 
(A) a repeating unit of the formula (I'): 
##STR5## 
derived from the monomer (I), (B) a repeating unit of the formula (II'): 
##STR6## 
derived from the monomer (II), and (C) a repeating unit of the formula 
(III'-1) and/or (III'-2): 
##STR7## 
derived from the monomer (III-1) and/or (III-2), wherein R.sup.1 and 
R.sup.2 represent a substituent containing an ethylenically unsaturated 
group, a substituent containing a reactive silicon group, or a substituent 
containing an epoxy group at the end, which is represented by the formula 
(IV): 
##STR8## 
wherein R.sup.3 is a divalent organic residue comprising at least one atom 
selected from carbon, oxygen and hydrogen atoms. 
A polymerization method for obtaining the polyether copolymer of the 
present invention is a polymerization method wherein a copolymer is 
obtained by a ring-opening reaction of the ethylene oxide portion, and is 
described in Japanese Patent Kokai Publication Nos. 169823/1987 and 
324129/1995 filed by the present applicant. That is, the polyether 
copolymer can be obtained by reacting the respective monomers at the 
reaction temperature of 10 to 80.degree. C. under stirring, using a 
catalyst mainly composed of an organoaluminum, a catalyst mainly composed 
of organozinc, an organotin-phosphoric ester condensate catalyst, etc. as 
a ring-opening catalyst in the presence or absence of a solvent. 
Particularly, in case where an oxirane compound having an epoxy group at 
only both ends is used, when using the organotin-phosphoric ester 
condensate catalyst, only an epoxy group which does not contain a 
substituent, i.e. methyl group is used in the polymerization reaction and, 
therefore, an epoxy group having a methyl group remains in the polymer 
without being reacted. The organotin-phosphoric ester condensate catalyst 
is particularly preferable in view of the polymerization degree, or 
properties of the resultant copolymer, etc. 
As the polyether copolymer of the present invention used as a raw material 
for a crosslinked material, those comprising 4 to 40% by mol of the 
repeating unit (A), 95 to 59% by mol of the repeating unit (B) and 0.001 
to 15% by mol of the repeating unit (C) are used. Those comprising 5 to 
35% by mol, particularly 9 to 30% by mol, of the repeating unit (A), 64 to 
94% by mol, particularly 69 to 90% by mol, of the repeating unit (B) and 
0.01 to 10% by mol, particularly 0.1 to 10% by mol, of the repeating unit 
(C) are preferred. 
When the content of the repeating unit (B) exceeds 95% by mol, 
crystallization of the oxyethylene chain arise and diffusion transfer of 
carrier ions are lowered, which results in drastic deterioration of the 
ionic conductivity of the solid electrolyte. When the content of the 
repeating unit (B) is smaller than 59% by mol, an increase in glass 
transition temperature arises, which results in deterioration of the 
dissociation capability of the salt and ionic conductivity. 
It is generally known that the ionic conductivity is improved by 
deterioration of the crystallizability of polyethylene oxide and decrease 
in glass transition temperature. It has been found that, the effect for 
improvement of the ionic conductivity is remarkably large by an optimum 
balance of the monomeric composition of the polyether copolymer of the 
present invention. 
When a molar ratio of the crosslinking monomer component (monomer capable 
of forming the repeating unit (C)) is larger than 15% by mol, the ionic 
conductivity is drastically lowered and the flexibility is lost in case of 
producing a film, thereby causing problems in processability and 
moldability. 
The polyether copolymer of the present invention may be any of a block 
copolymer and a random copolymer. The random copolymer is more preferred 
because of its large effect of lowering the crystallizability of 
polyethylene oxide. 
Regarding the molecular weight of the polyether copolymer, the 
weight-average molecular weight is within a range from 10.sup.4 to 
10.sup.7, and preferably from 10.sup.5 to 5.times.10.sup.6, so as to 
obtain excellent processability, moldability, mechanical strength and 
flexibility. When the weight-average molecular weight is smaller than 
10.sup.4, it becomes necessary to increase the crosslink density to 
maintain the mechanical strength and to prevent flow at high temperature 
and, therefore, the ionic conductivity of the resultant electrolyte is 
lowered. On the other hand, when it exceeds 10.sup.7, problems arise in 
processability and moldability. 
The repeating unit (A) is derived from epichlorohydrin. The repeating unit 
(B) is derived from ethylene oxide. 
The monomer constituting the repeating unit (C) is an oxirane compound 
containing an ethylenically unsaturated group, an oxirane compound 
containing a reactive silicon group, or an oxirane compound containing an 
epoxy group at each of both ends. 
In the case of the oxirane compound containing an epoxy group at both ends, 
R.sup.1 in the monomer of the formula (III-1) is represented by the 
formula (IV) and R.sup.3 is an organic residue comprising at least one 
atom selected from carbon, oxygen and hydrogen atoms. 
The monomer having the ethylenically unsaturated group is preferably an 
oxirane compound represented by the formula (III-a): 
##STR9## 
wherein R.sup.4 is a group having an ethylenically unsaturated group. 
As the ethylenically unsaturated group-containing oxirane compound, there 
can be used allyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, 
.alpha.-terpinyl glycidyl ether, cyclohexenylmethyl glycidyl ether, 
p-vinylbenzyl glycidyl ether, allylphenyl glycidyl ether, vinyl glycidyl 
ether, 3, 4-epoxy-1-butene, 3, 4-epoxy-1-pentene, 4, 5-epoxy-2-pentene, 1, 
2-epoxy-5, 9-cyclododecadiene, 3, 4epoxy-1-vinylcyclohexene, 1, 
2-epoxy-5-cyclooctene, glycidyl acrylate, glycidyl methacrylate, glycidyl 
sorbate, glycidyl cinnamate, glycidyl crotonate, glycidyl-4-hexenoate, 
oligoethylene glycol glycidyl ether acrylate having 1 to 12 oxyethylene 
chains, oligoethylene glycol glycidyl ether methacrylate having 1 to 12 
oxyethylene chains, oligoethylene glycol allyl glycidyl ether having 1 to 
12 oxyethylene chains. Preferable examples thereof include allyl glycidyl 
ether, glycidyl acrylate and glycidyl methacrylate. 
The monomer having a reactive silicon group, which constitutes the 
repeating unit (C), is preferably an oxirane compound represented by the 
formula (III-b-1): 
##STR10## 
wherein R.sup.5 is a reactive silicon-containing group, or the formula 
(III-b-2): 
##STR11## 
wherein R.sup.6 is a reactive silicon-containing group. 
The reactive silicon group-containing oxirane compound represented by the 
formula (III-b-1) is preferably a compound represented by the formula 
(III-b-1-1) or (III-b-1-2). 
##STR12## 
The reactive silicon group-containing monomer represented by the formula 
(III-b-2) is preferably a compound represented by the formula (III-b-2-1). 
##STR13## 
In the formulas (III-b-1-1), (III-b-1-2) and (III-b-2-1), R.sup.7, R.sup.8 
and R.sup.9 may be the same or different, but at least one of them 
represents an alkoxy group and the remainder represent an alkyl group; and 
m represents 1 to 6. 
Examples of the monomer represented by the formula (III-b-1-1) include 
1-glycidoxymethyltrimethoxysilane, 1-glycidoxymethylmethyldimethoxysilane, 
2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethylmethyldimethoxysilane, 
3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 
4-glycidoxybutylmethyldimethoxysilane, 4-glycidoxybutyltrimethoxysilane, 
6-glycidoxyhexylmethyldimethoxysilane and 
6-glycidoxyhexyltrimethoxysilane. 
Examples of the monomer represented by the formula (III-b-1-2) include 
3-(1, 2-epoxy) propyltrimethoxysilane, 3-(1, 2-epoxy) 
propylmethyldimethoxysilane, 3-(1, 2-epoxy) propyldimethylmethoxysilane, 
4-(1, 2-epoxy) butyltrimethoxysilane, 4-(1, 2-epoxy) 
butylmethyldimethoxysilane, 5-(1, 2-epoxy) pentyltrimethoxysilane, 5-(1, 
2-epoxy) pentylmethyldimethoxysilane, 6-(1, 2-epoxy) hexyltrimethoxysilane 
and 6-(1, 2-epoxy) hexylmethyldimethoxysilane. 
Examples of the monomer represented by the formula (III-b-2-1) include 
1-(3, 4-epoxycyclohexyl) methyltrimethoxysilane, 1-(3, 4-epoxycyclohexyl) 
methylmethyl-dimethoxysilane, 2-(3, 4-epoxycyclohexyl) 
ethyltrimethoxysilane, 2-(3, 4-epoxycyclohexyl) 
ethylmethyldimethoxysilane, 3-(3, 4-epoxycyclohexyl) 
propyltrimethoxysilane, 3-(3, 
4-epoxycyclohexyl)propylmethyldimethoxysilane, 4-(3, 4-epoxycyclohexyl) 
butyltrimethoxysilane and 4-(3, 4-epoxycyclohexyl) 
butylmethyldimethoxysilane. 
Among them, 3-glycidoxypropyltrimethoxysilane, 
3-glycidoxypropyl-methyldimethoxysilane, 4-(1, 2-epoxy) 
butyltrimethoxysilane, 5-(1, 2-epoxy)pentyltrimethoxysilane and 2-(3, 
4-epoxycyclohexyl)ethyltrimethoxysilane are particularly preferable. 
The monomer having two epoxy groups at both ends, which constitutes the 
repeating unit (C), is preferably represented by the formula (III-c): 
##STR14## 
wherein R.sup.10 is a divalent organic group. R.sup.10 is preferably an 
organic group comprising elements selected from hydrogen, carbon and 
oxygen. 
It is preferable that the group R.sup.10 in the formula (III-c) is 
EQU --CH.sub.2 --O--(CHA.sup.1 --CHA.sup.2 --O).sub.p --CH.sub.2 --, 
EQU --(CH.sub.2).sub.p --, 
or 
EQU --CH.sub.2 O--Ph--OCH.sub.2 -- 
wherein A.sup.1 and A.sup.2 represent hydrogen or a methyl group; Ph 
represents a phenylene group; and p represents a numeral of 0 to 12. 
The monomer having two epoxy groups at both ends is preferably a compound 
represented by the following formula (III-c-1), (III-c-2) or (III-c-3): 
##STR15## 
In the above formulas (III-c-1), (III-c-2) and (III-c-3), A.sup.1 and 
A.sup.2 represent hydrogen or a methyl group; and p represents a numeral 
of 0 to 12. 
Examples of the monomer represented by the formula (III-c-1) include 2, 
3-epoxypropyl-2', 3'-epoxy-2'-methyl propyl ether, ethylene glycol-2, 
3-epoxypropyl-2', 3'-epoxy-2'-methyl propyl ether, and diethylene 
glycol-2, 3-epoxypropyl-2', 3'-epoxy-2'-methyl propyl ether. Examples of 
the monomer represented by the formula (III-c-2) include 2-methyl-1, 2, 3, 
4-diepoxybutane, 2-methyl-1, 2, 4, 5-diepoxypenatane, and 2-methyl-1, 2, 
5, 6-diepoxyhexane. Examples of the monomer represented by the formula 
(III-c-3) include hydroquinone-2, 3-epoxypropyl-2', 3'-epoxy-2'-methyl 
propyl ether, and catechol-2, 3-epoxypropyl-2', 3'-epoxy-2'-methyl propyl 
ether. 
Among them, 2, 3-epoxypropyl-2', 3'-epoxy-2'-methyl propyl ether and 
ethylene glycol-2, 3-epoxypropyl-2', 3'-epoxy-2'-methyl propyl ether are 
particularly preferable. 
In the crosslinking method of the copolymer wherein the reactive functional 
group is ethylenically unsaturated group, a radical initiator selected 
from an organic peroxide and an azo compound, or active energy ray such as 
ultraviolet ray and electron ray can be used. It is also possible to use a 
crosslinking agent having a silicon hydride. 
As the organic peroxide, there can be used those which are normally used in 
the crosslinking, such as a ketone peroxide, a peroxy ketal, a 
hydroperoxide, a dialkyl peroxide, a diacyl peroxide and a peroxy ester. 
Specific examples of the organic peroxide include methyl ethyl ketone 
peroxide, cyclohexanone peroxide, 1, 1-bis(t-butylperoxy)-3, 3, 
5-trimethylcyclohexane, 2, 2-bis(t-butylperoxy)octane, 
n-butyl-4,4-bis(t-butylperoxy)valerate, t-butyl hydroperoxide, cumene 
hydroperoxide, 2, 5-dimethylhexane-2, 5-dihydroperoxide, di-t-butyl 
peroxide, t-butylcumyl peroxide, dicumyl peroxide, .alpha., 
.alpha.'-bis(t-butylperoxy-m-isopropyl)benzene, 2, 5-dimethyl-2, 
5-di(t-butylperoxy)hexane, 2, 5-dimethyl-2, 5-di(t-butylperoxy)hexene, 
benzoylperoxide and t-butylperoxyisopropylcarbonate. The amount of the 
organic peroxide varies depending on the type of the organic peroxide, but 
it is normally within the range from 0.1 to 10% by weight based on the 
whole composition constituting the solid polymer electrolyte. 
As the azo compound, there can be used those which are normally used in the 
crosslinking, such as an azonitrile compound, an azoamide compound and an 
azoamidine compound. Specific examples of the azo compound include 2, 
2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2, 
2'-azobis (4-methoxy-2, 4-dimethylvaleronitrile), 2, 2'-azobis(2, 
4-dimethylvaleronitrile), 1, 1'-azobis (cyclohexane-1-carbonitrile), 
2-(carbamoylazo) isobutyronitrile, 2-phenylazo-4-methoxy-2, 
4-dimethyl-valeronitrile, 2, 2-azobis (2-methyl-N-phenylpropionamidine) 
dihydrochloride, 2, 2'-azobis [N-(4-chlorophenyl)-2-methylpropionamidine] 
dihydrochloride, 2, 2'-azobis [N-(hydroxyphenyl)-2-methylpropionamidine] 
dihydrochloride, 2, 2'-azobis [2-methyl-N-(phenylmethly) propionamidine] 
dihydrochloride, 2,2'-azobis [2-methyl-N-(2-propenyl) propionamidine] 
dihydrochloride, 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2, 
2'-azobis [N-(2-hydroxyethyl)-2-methylpropionamidine]dihydrochloride, 2, 
2'-azobis[2-(5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2, 
2'-azobis[2-(2-imidazolin-2-yl) propane] dihyrochloride, 2, 2'-azobis 
[2-(4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) propane] dihydrochloride, 2, 
2'-azobis [2-(3,4,5,6tetrahydropyrimidin-2-yl) propane] dihydrochloride, 
2, 2'-azobis [2-(5-hydroxy-3,4,5,6-tetrahydropyrimidin-2-yl) propane] 
dihydrochloride, 2, 2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl] 
propane} dihydrochloride, 2, 2'-azobis [2-(2-imidazolin-2-yl) propane], 2, 
2'-azobis {2-methyl-N-[1,1 -bis(hydroxymethyl)-2-hydroxyethyl] 
propionamide}, 2, 2'-azobis {2-methyl-N-[1,1-bis (hydroxymethyl) ethyl] 
propionamide}, 2, 2'-azobis [2-methyl-N-(2-hydroxyethyl) propionamide], 
2,2'-azobis (2-methylpropionamide) dihydrate, 2, 2'-azobis 
(2,4,4-trimethylpentane), 2, 2'-azobis (2-methylpropane), dimethyl 2, 
2'-azobisisobutyrate, 4, 4'-azobis (4-cyanovaleric acid) and 2,2'-azobis 
[2-(hydroxymethyl) propionitrile]. The amount of the azo compound varies 
depending on the type of the azo compound, but is normally within the 
range from 0.1 to 10% by weight based on the whole composition 
constituting the polymer solid electrolyte. 
In the crosslinking due to radiation of activated energy ray such as 
ultraviolet ray, glycidyl acrylate, glycidyl methacrylate and glycidyl 
cinnamate are particularly preferable among the monomer component 
represented by the formula (III-c). 
Furthermore, as the auxiliary sensitizer, there can be optionally used 
acetophenones such as diethoxyacetophenone, 2-hydroxy-2-methyl-1 
-phenylpropan-1-one, benzyldimethylketal, 
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy) 
phenyl-(2-hydroxy-2-propyl) ketone, 
2,2-dimethoxy-1,2-diphenyl-ethan-1-one, 1-hydroxycyclohexyl-phenylketone 
and 2-methyl-2-morpholino (4-thio-methylphenyl) propan-1-one; benzoin 
ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin 
isopropyl ether and benzoin isobutyl ether; benzophenones such as 
benzophenone, methyl o-benzoyl benzoate, 4-phenylbenzophenone, 
hydroxy-benzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, alkylated 
benzophenone, 3, 3', 4, 4'-tetra (t-butylperoxycarbonyl) benzophenone, 
4-benzoyl-N, N-dimethyl-N-[2-(1-oxo-2-propenyloxy) ethyl] 
benzenemethanaminium bromide and (4-benzoylbenzyl) trimethylammonium 
chloride; thioxanthones such as 2-isopropylthioxanthone, 2, 
4-dimethylthioxanthone, 2, 4-diethylthioxanthone and 2, 
4-dichlorothioxanthone; azides such as azidopyrene, 3-sulfonylazidobenzoic 
acid, 4-sulfonylazidobenzoic acid, 2, 
6-bis(4'-azidobenzal)cyclohexanone-2, 2'-disulfonic acid (sodium salt), 
p-azidobenzaldehyde, p-azidoacetophenone, p-azidobenzoinic acid, 
p-azidobenzalacetophenone, p-azidobenzalacetone, 4, 4'-diazidochalcone, 1, 
3-bis (4'-azidobenzal) acetone, 2, 6-bis (4'-azidobenzal) cyclohexanone, 
2, 6-bis(4-azidobenzal) 4-methylcyclohexanone, 4, 4'-diazidostilbene-2, 
2'-disulfonic acid, 1,3-bis (4'-azidobenzal)-2-propanone-2'-sulfonic acid 
and 1,3-bis (4'-azidocinnacylidene)-2-propanone. 
As a crosslinking aid, there can be optionally used ethylene glycol 
diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 
polyethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene 
glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene 
glycol dimethacrylate, oligoethylene glycol diacrylate, oligoethylene 
glycol dimethacrylate, propylene glycol diacrylate, propylene glycol 
dimethacrylate, oligopropylene glycol diacrylate, oligopropylene glycol 
dimethacrylate, 1, 3-butylene glycol diacrylate, 1, 4-butylene glycol 
diacrylate, 1, 3-glycerol dimethacrylate, 1, 1, 1-trimethylolpropane 
dimethacrylate, 1, 1, 1-trimethylolethane diacrylate, pentaerythritol 
trimethacrylate, 1, 2, 6-hexanetriacrylate, sorbitol pentamethacrylate, 
methylenebisacrylamide, methylenebismethacrylamide divinyl benzene, vinyl 
methacrylate, vinyl crotonate, vinyl acrylate, vinyl acetylene, trivinyl 
benzene, triallyl cyanyl sulfide, divinyl ether, divinyl sulfo ether, 
diallyl phthalate, glycerol trivinyl ether, allyl methacrylate, allyl 
acrylate, diallyl maleate, diallyl fumarate, diallyl itaconate, methyl 
methacrylate, butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 
lauryl methacrylate, ethylene glycol acrylate, triallyl isocyanurate, 
maleimide, phenylmaleimide, N,N-m-phenylenebismaleimide, p-quinonedioxime, 
maleic anhydride and itaconic acid. 
As a crosslinking agent having a silicon hydride group, which is used for 
crosslinking the ethylenically unsaturated group, a compound having at 
least two silicon hydride groups can be used. Particularly, a polysiloxane 
compound or a polysilane compound is preferable. 
Examples of the polysiloxane compound include a linear polysiloxane 
compound represented by the formula (a-1) or (a-2), or a cyclic 
polysiloxane compound represented by the formula (a-3). 
##STR16## 
In the formulas (a-1) to (a-3), R.sup.11, R.sup.12, R.sup.13, R.sup.14, 
R.sup.15, R.sup.16, R.sup.17, R.sup.18 and R.sup.19 respectively represent 
a hydrogen atom or an alkyl or alkoxy group having 1 to 12 carbon atoms; 
and q and r are an integer provided that r.gtoreq.2, 
q.gtoreq.0,2.ltoreq.q+r.ltoreq.300. As the alkyl group, a lower alkyl 
group such as a methyl group and an ethyl group is preferable. As the 
alkoxy group, a lower alkoxy group such as a methoxy group and an ethoxy 
group is preferable. 
As the polysilane compound, a linear polysilane compound represented by the 
formula (b-1) can be used. 
##STR17## 
In the formula (b-1), R.sup.20, R.sup.21, R.sup.22, R.sup.23 and R.sup.24 
respectively represent a hydrogen atom or an alkyl or alkoxy group having 
1 to 12 carbon atoms; and s and t are an integer provided that t.gtoreq.2, 
s.gtoreq.0, 2.ltoreq.s+t.ltoreq.100. 
Examples of the catalyst of the hydrosilylation reaction include transition 
metals such as palladium and platinum or a compound or complex thereof 
Furthermore, peroxide, amine and phosphine can also be used. The most 
popular catalyst includes dichlorobis(acetonitrile)palladium(II), 
chlorotris(triphenylphosphine)rhodium(I) and chloroplatinic acid. 
As the crosslinking method of the copolymer wherein the reactive functional 
group is a reactive silicon group, the crosslinking can be conducted by 
the reaction between the reactive silicon group and water. In order to 
increase the reactivity, there may be used, as a catalyst, organometal 
compounds, for example, tin compounds such as dibutyltin dilaurate, 
dibutyltin maleate, dibutyltin diacetate, tin octylate and dibutyltin 
acetylacetonate; titanium compounds such as tetrabutyl titanate and 
tetrapropyl titanate; aluminum compounds such as aluminum trisacetyl 
acetonate, aluminum trisethyl acetoacetate and diisopropoxyaluminum 
ethylacetoacetate; or amine compounds such as butylamine, octylamine, 
laurylamine, dibutylamine, monoethanolamine, diethanolamine, 
triethanolamine, diethylenetriamine, trietylenetetraamine, 
cyclohexylamine, benzylamine, diethylaminopropylamine, guanine and 
diphenylguanine. 
As the crosslinking method of the copolymer wherein the reactive functional 
group is an epoxy group, polyamines, acid anhydrides and the like can be 
used. 
Examples of the polyamines include aliphatic polyamines such as 
diethylenetriamine, dipropylenetriamine, triethylenetetramine, 
tetraethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, 
dibutylaminopropylamine, hexamethylenediamine, N-aminoethylpiperazine, 
bis-aminopropylpiperazine, trimethylhexamethylenediamine and dihydrazide 
isophthalate; and aromatic polyamines such as 4, 4'-diaminodiphenyl ether, 
diaminodiphenyl sulfone, m-phenylenediamine, 2, 4-toluylenediamine, 
m-toluylenediamine, o-toluylenediamine and xylylenediamine. The amount of 
the polyamine varies depending on the type of the polyamine, but is 
normally within the range from 0.1 to 10% by weight based on the whole 
composition constituting the solid polymer electrolyte. 
Examples of the acid anhydrides includes maleic anhydride, 
dodecenylsuccinic anhydride, chlorendic anhydride, phthalic anhydride, 
pyromellitic anhydride, hexahydrophthalic anhydride, 
methylhexahydrophthalic anhydride, tetramethylenemaleic anhydride, 
tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride and 
trimellitic anhydride. The amount of the acid anhydrides varies depending 
on the type of the acid anhydride, but is normally within the range from 
0.1 to 10% by weight based on the whole composition. In the crosslinking, 
an accelerator can be used. In the crosslinking reaction of polyamines, 
examples of the accelerator include phenol, cresol, resorcin, pyrogallol, 
nonyl phenol and 2, 4, 6-tris(dimethylaminomethyl)phenol. In the 
crosslinking reaction of the acid anhydride, examples of the accelerator 
include benzyldimethylamine, 2, 4, 6-tris(dimethylaminomethyl)phenol, 
2-(dimethylaminoethyl)phenol, dimethylaniline and 
2-ethyl-4-methylimidazole. The amount of the accelerator varies depending 
on the type of the accelerator, but is normally within the range from 0.1 
to 10% by weight based on the crosslinking agent. 
The electrolyte salt compound used in the present invention is preferably 
soluble in the polyether copolymer or in the crosslinked material of the 
polyether copolymer. In the present invention, the following electrolyte 
salt compounds are preferably used. 
That is, examples thereof include a compound composed of a cation selected 
from metal cation, ammonium ion, amidinium ion and guanidium ion, and an 
anion selected from chloride ion, bromide ion, iodide ion, perchlorate 
ion, thiocyanate ion, tetrafluoroborate ion, nitrate ion, AsF.sub.6.sup.-, 
PF.sub.6.sup.-, stearylsulfonate ion, octylsulfonate ion, 
dodecylbenzenesulfonate ion, naphthalenesufonate ion, 
dodecylnaphthalenesulfonate ion, 7, 7, 8, 8-tetracyano-p-quinodimethane 
ion, X.sup.1 SO.sub.3.sup.-, [(X.sup.1 SO.sub.2)(X.sup.2 
SO.sub.2)N].sup.-, [(X.sup.1 SO.sub.2)(X.sup.2 SO.sub.2)(X.sup.3 
SO.sub.2)C].sup.- and [(X.sup.1 SO.sub.2)(X.sup.2 SO.sub.2)YC].sup.-, 
wherein X.sup.1, X.sup.2, X.sup.3 and Y respectively represent an electron 
attractive group. Preferably, X.sup.1, X.sup.2 and X.sup.3 independently 
represent a perfluoroalkyl having 1 to 6 carbon atoms or a perfluoroaryl 
group and Y represents a nitro group, a nitroso group, a carbonyl group, a 
carboxyl group or a cyano group. X.sup.1, X.sup.2 and X.sup.3 may be the 
same or different. 
As the metal cation, a cation of a transition metal can be used. 
Preferably, a cation of a metal selected from Mn, Fe, Co, Ni, Cu, Zn and 
Ag metals is used. When using a cation of a metal selected from Li, Na, K, 
Rb, Cs, Mg, Ca and Ba metals, good results are also obtained. Two or more 
compounds described above may be used as the electrolyte salt compound. 
In the present invention, the amount of the electrolyte salt compound is so 
that a numeral value of a molar ratio of the number of moles of the 
electrolyte salt compound to the total number of moles of ether oxygen 
atom in the main and side chains of the polyether copolymer (the total 
number of moles of ether oxygen atom included in the polyether copolymer) 
is preferably within the range from 0.0001 to 5, more preferably from 
0.001 to 0.5. When this value exceeds 5, the processability and 
moldability, the mechanical strength and flexibility of the resultant 
solid electrolyte are deteriorated. 
When the flame retardancy is required in using the polyether copolymer, the 
crosslinked material thereof and the solid polymer electrolyte, a flame 
retardant can be used. That is, an effective amount of those selected from 
a halide (such as a brominated epoxy compound, tetrabromobisphenol A and 
chlorinated paraffin), antimony trioxide, antimony pentaoxide, aluminum 
hydroxide, magnesium hydroxide, phosphate ester, polyphosphate salt and 
zinc borate as a flame retardant can be added. 
The method for production of the crosslinked solid polymer electrolyte of 
the present invention is not specifically limited, but the crosslinked 
solid polymer electrolyte is normally produced by a method of mechanically 
mixing a polyether copolymer with an electrolyte salt compound or mixing 
after dissolving them in a solvent, removing the solvent, and 
crosslinking, or a method of crosslinking a polyether copolymer and 
mechanically mixing the crosslinked polyether copolymer with an 
electrolyte salt compound or mixing after dissolving them in a solvent and 
removing the solvent. As a means for mechanically mixing, various 
kneaders, open rolls, extruders, etc. can be optionally used. In case of 
producing the crosslinked solid polymer electrolyte by using the solvent, 
various polar solvents such as tetrahydrofuran, acetone, acetonitrile, 
dimethyl formamide, dimethyl sulfoxide, dioxane, methyl ethyl ketone, 
methyl isobutyl ketone, toluene and ethylene glycol diethyl ether may be 
used alone or in combination thereof. The concentration of the solution is 
preferably from 1 to 50% by weight, but is not limited thereto. 
When the copolymer having an ethylenically unsaturated group is crosslinked 
by using a radical initiator, the crosslinking reaction is completed at 
the temperature range of 1 to 200.degree. C. within 1 minute to 20 hours. 
When using energy radiation such as ultraviolet radiation, a sensitizer is 
normally used. The crosslinking reaction is normally completed at the 
temperature range of 10 to 150.degree. C. within 0.1 second to 1 hour. In 
case of the crosslinking agent having silicon hydride, the crosslinking 
reaction is completed at the temperature of 10 to 180.degree. C. within 10 
minutes to 10 hours. 
In case that the reactive functional group is a reactive silicon group, the 
amount of water used in the crosslinking reaction is not specifically 
limited because the crosslinking reaction easily occurs even in the 
presence of moisture in the atmosphere. The crosslinking can also be 
conducted by passing through a cold water or hot water bath for a short 
time, or exposing to a steam atmosphere. 
When using a polyamine or an acid anhydride in the crosslinking reaction of 
the copolymer having an epoxy group, the crosslinking reaction is 
completed at the temperature of 10 to 200.degree. C. within 10 minutes to 
20 hours. 
The copolymer and crosslinked material of said copolymer shown in the 
present invention become a precursor useful as a crosslinked solid polymer 
electrolyte. The solid polymer electrolyte shown in the present invention 
is superior in mechanical strength and flexibility, and a large area 
thin-film shaped solid electrolyte can be easily obtained by utilizing the 
properties. For example, it is possible to make a battery comprising the 
solid polymer electrolyte of the present invention. In this case, examples 
of the positive electrode material include lithium-manganese oxide, 
lithium-vanadium oxide, lithium cobaltate, lithium nickelate, 
cobalt-substituted lithium nickelate, vanadium pentaoxide, polyacene, 
polypyrene, polyaniline, polyphenylene, polyphenylene sulfide, 
polyphenylene oxide, polypyrrole, polyfuran, and polyazulene. Examples of 
the negative electrode material include an interlaminar compound prepared 
by occlusion of lithium between graphite or carbon layers, a lithium metal 
and a lithium-lead alloy. By utilizing the high ion conductivity, the 
crosslinked solid polymer electrolyte can also be used as a diaphragm of 
an ion electrode of the cation such as alkaline metal ion, Cu ion, Ca ion 
and Mg ion. 
The solid polymer electrolyte of the present invention is especially 
suitable as a material for electrochemical device (e.g. a battery, a 
capacitor and a sensor).

PREFERRED EMBODIMENTS OF THE INVENTION 
The following Examples further illustrate the present invention in detail. 
Preparation Example (production of catalyst) 
Tributyltin chloride (10 g) and tributyl phosphate (35 g) were charged in a 
three-necked flask equipped with a stirrer, a thermometer and a 
distillation device, and the mixture was heated at 250.degree. C. for 20 
minutes with stirring under nitrogen stream and the distillate was 
distilled off to obtain a solid condensate as a residue product. In the 
following polymerization, this condensate was used as a polymerization 
catalyst. 
The results of the composition analysis (in terms of monomer) of the 
polyether copolymer by elemental analysis, iodine value and .sup.1 H NMR 
spectrum were shown in Table 1 and Table 2. In case of the measurement of 
the molecular weight of the polyether copolymer, the gel permeation 
chromatography measurement was conducted and the molecular weight was 
calculated in terms of standard polystyrene. The gel permeation 
chromatography measurement was conducted at 60.degree. C. by a measuring 
device RID-6A manufactured by Shimadzu Corp., using a column manufactured 
by Showa Denko K. K. such as Showdex KD-807, KD-806, KD-806M and KD-803, 
and a solvent DMF. The glass transition temperature and the heat of fusion 
were measured in a nitrogen atmosphere within a temperature range from 
-100 to 80.degree. C. at a heating rate of 10.degree. C./min., using a 
differential scanning calorimeter DSC8230B manufactured by Rigaku Denki 
K.K. The measurement of the conductivity .sigma. cr was conducted as 
follows. That is, a film vacuum-dried at 20.degree. C. under 1 mmHg for 72 
hours was sandwiched between platinum electrodes and the conductivity was 
calculated according to the complex impedance method, using an A.C. method 
(voltage: 0.5 V, frequency: 5 Hz to 1 MHz). The flexibility of the solid 
electrolyte film was evaluated by the presence or absence of breakage in 
case of folding the film at an angle of 180 degrees at 25.degree. C. 
EXAMPLE 1 
After the atmosphere in a four-necked glass flask (internal volume: 1 L) 
was replaced by nitrogen, the condensate (300 mg) obtained in the 
Preparation Example of the catalyst as the catalyst, allyl glycidyl ether 
(11 g) having a water content adjusted to not more than 10 ppm, 
epichlorohydrin (81 g) and n-hexane (500 g) as the solvent were charged in 
the flask, and ethylene oxide (100 g) was gradually added with monitoring 
the polymerization degree of epichlorohydrin by gas chromatography. The 
polymerization reaction was conducted at 20.degree. C. for 20 hours. The 
polymerization reaction was terminated by using methanol. The polymer was 
isolated by decantation, dried at 40.degree. C. under a normal pressure 
for 24 hours, and then dried at 45.degree. C. under reduced pressure for 
10 hours to give 185 g of a polymer. The glass transition temperature of 
this copolymer was -32.degree. C., the weight-average molecular weight was 
1,300,000 and the heat of fusion was 29 J/g. The component of 
epichlorohydrin was determined by elemental analysis of chlorine, whereas, 
the component of allyl glycidyl ether was determined by the measurement of 
the iodine value. The results of the composition analysis (in terms of 
monomers) are as shown in Table 1. 
The resultant copolymer (1 g) and dicumyl peroxide (0.015 g) as a 
crosslinking agent were dissolved in acetonitrile (5 ml), and the 
resultant solution was mixed with lithium perchlorate (electrolyte salt 
compound) so that a molar ratio of (the number of mols of the electrolyte 
salt compound to the total number of moles of ether oxygen atoms of 
copolymer) was 0.05. This mixture solution was cast on a mold made of 
polytetarfluoroethylene, followed by sufficient drying and further heating 
under a nitrogen atmosphere at 150.degree. C. for 3 hours to give a film. 
The measurement results of the conductivity and flexibility of the film 
are shown in Table 1. 
EXAMPLE 2 
Using the monomers shown in Table 1, the copolymerization was conducted by 
using the same catalyst and operation as those of Example 1. The resultant 
polyether copolymer (1 g), triethylene glycol dimethacrylate (0.05 g) and 
benzoyl oxide (0.015 g) as a crosslinking agent were dissolved in 
acetonitrile (20 ml), and the resultant solution was mixed with lithium 
bistrifluoromethanesulfonylimide (electrolyte salt compound) so that a 
molar ratio of (the number of moles of the electrolyte salt compound to 
the total number of moles of ether oxygen atoms of copolymer) was 0.05. 
This mixture solution was heated under a nitrogen atmosphere at 
100.degree. C. for 3 hours to give a film. The measurement results of the 
conductivity and flexibility of the film are shown in Table 1. 
EXAMPLE 3 
Using the monomers shown in Table 1, the copolymerization was conducted by 
using the same catalyst and operation as those of Example 1. The resultant 
polyether copolymer (1 g), triethylene glycol diacrylate (0.05 g) and 
2,2-dimethoxy-1,2-diphenylethan-1-one (0.02 g) as a sensitizing agent were 
dissolved in acetonitrile (5 ml), and the resultant solution was mixed 
with lithium perchlorate (electrolyte salt compound) so that a molar ratio 
of (the number of mols of the electrolyte salt compound to the total 
number of moles of ether oxygen atoms of copolymer) was 0.05. This mixture 
solution was cast on a mold made of polytetrafluoroethylene, dried and 
then exposed to ultraviolet radiation (30 mW/cm.sup.2, 360 nm) under an 
argon atmosphere at 50.degree. C. for 10 minutes to give a film. The 
measurement results of the conductivity and flexibility of the film are 
shown in Table 1. 
EXAMPLE 4 
Using the monomers shown in Table 1, the copolymerization was conducted by 
using the same catalyst and operation as those of Example 1. The resultant 
polyether copolymer (1 g) and dibutyltin dilaurate (5 mg) as a catalyst 
were dissolved in tetrahydrofuran (20 ml) and water (10 .mu.l) was added, 
followed by stirring for 15 minutes. After the solvent was removed under 
normal pressure, the mixture solution was dried at 60.degree. C. for 10 
hours to give a crosslinked material. The resultant crosslinked material 
was impregnated with a tetrahydrofuran solution (5 ml) containing lithium 
perchlorate (100 mg) for 20 hours, heated at 170.degree. C. under 80 
kgw/cm.sup.2 for 10 minutes and pressurized to give a film. The 
measurement results of the conductivity and flexibility of the film are 
shown in Table 1. 
EXAMPLE 5 
Using the monomers shown in Table 1, the copolymerization was conducted by 
using the same catalyst and operation as those of Example 1. The resultant 
polyether copolymer (1 g) and maleic anhydride (150 mg) were dissolved in 
acetonitrile (10 ml), and the resultant solution was mixed with lithium 
perchlorate (electrolyte salt compound) so that a molar ratio of (the 
number of moles of the soluble electrolyte salt compound to the total 
number of moles of ether oxygen atoms of copolymer) was 0.05. This mixture 
solution was cast on a mold made of polytetrafluoroethylene, dried and 
then heated at 150.degree. C. under 20 kgw/cm.sup.2 for one hour and 
pressurized to give a film. The measurement results of the conductivity 
and flexibility of the film are shown in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Copolymer and solid polymer electrolyte 
Example No. 
1 2 3 4 5 
__________________________________________________________________________ 
Charged monomer (% by mol) 
Ethylene oxide 70 80 85 90 65 
Epichlorohydrin 27 19 13 9.97 28 
Allyl glycidyl ether 3 1 
Glycidyl methacrylate 2 
3-glycidoxypropyltrimethoxysilane 0.03 
2,3-epoxypropyl-2',3'-epoxy-2'-methyl propyl ether 7 
Composition of produced polymer (% by mol) 
Ethylene oxide 72 81 87 92.3 67 
Epichlorohydrin 25 18 11 7.67 26 
Allyl glycidyl ether 3 1 
Glycidyl methacrylate 2 
3-glycidoxypropyltrimethoxysilane 0.03 
2,3-epoxypropyl-2',3'-epoxy-2'-methyl propyl ether 7 
Weight-average molecular weight of copolymer 1,300,000 1,900,000 
2,100,000 3,520,000 
760,000 
Glass transition temperature of copolymer (.degree. C.) -32 -53 -54 -55 
-51 
Heat of fusion of copolymer (J/g) 29 32 35 49 19 
Flexibility of solid electrolyte film Not broken Not broken Not broken 
Not broken Not broken 
Conductivity of solid 
electrolyte film 
(S/cm) 
30.degree. C. 2.2 .times. 10.sup.-6 3.1 .times. 10.sup.-5 1.8 .times. 
10.sup.-5 8.7 .times. 
10.sup.-6 1.5 .times. 
10.sup.-6 
__________________________________________________________________________ 
COMATIVE EXAMPLES 1 TO 4 
The polyether copolymer shown in Table 2 was obtained in the same manner as 
in Example 1. 
In Comparative Examples 1 and 2, a film was molded in the same manner as in 
Example 1, except for adding no crosslinking agent. In Comparative Example 
3, a film was molded in the same manner as in Example 1. In Comparative 
Example 4, a film was molded in the same manner as in Example 4. The 
results are shown in Table 2. 
TABLE 2 
__________________________________________________________________________ 
Copolymer and solid polymer electrolyte 
Comparative Example No. 
1 2 3 4 
__________________________________________________________________________ 
Composition of produced copolymer (% by mol) 
Ethylene oxide 10 100 50 30 
Epichlorohydrin 90 48 69.9 
Allyl glycidyl ether 2 
3-glycidoxypropyltrimethoxysilane 0.1 
Weight-average molecular weight of copolymer 590,000 4,200,000 920,000 
660,000 
Glass transition temperature of copolymer ( 
.degree. C.) -27 -57 -46 -38 
Heat of fusion of copolymer 
(J/g) 57 179 5 28 
Flexibility of solid electrolyte film Broken Broken Not broken Not 
broken 
Conductivity of solid electrolyte film (S/cm) 
30.degree. C. 5.7 .times. 10.sup.-9 1.1 .times. 10.sup.-7 2.3 .times. 
10.sup.-7 3.2 .times. 10.sup.-8 
__________________________________________________________________________ 
It is apparent from a comparison of Examples with Comparative Examples that 
the ionic conductivity and mechanical characteristics of the crosslinked 
solid polymer electrolyte formed from the polyether copolymer of the 
present invention are excellent. 
EXAMPLE 6 
(1) Production of cathode (positive electrode) 
LiCoO.sub.2 powder (10 g), graphite (KS-15) (7.5 g), the copolymer obtained 
in Example 1 (7.5 g), dicumyl peroxide (0.025 g), LiBF.sub.4 (0.65 g) and 
acetonitrile (50 ml) were mixed under stirring by using a disperser to 
prepare a paste. This paste was coated on an aluminum foil and then dried 
to adhere a cathode material on the aluminum foil. Then, the cathode 
meterial was crosslinked by heating at 150.degree. C. for 3 hours in a 
drier having atmosphere replaced by nitrogen. 
(2) Assembling of battery 
A battery was assembled by adhering an Li foil (diameter: 16 mm, thickness: 
80 .mu.m) to one main surface of a solid polymer electrolyte film made in 
Example 1 or 2 and then further the above cathode to the other main 
surface of the solid polymer electrolyte film. This operation was 
conducted in a glove box under a dry argon atmosphere. 
(3) Charge/discharge test 
The resultant battery was charged up to 4.2 V at a temperature of 
50.degree. C. and a current density of 0.1 mA.sup.2 /cm, and discharged up 
to 3.0 V. In both cases of electrolyte films of Examples 1 and 2, a 
discharge capacity of 130 mAh per 1 g of LiCoO.sub.2 as an active 
substance was obtained. 
EFFECT OF THE INVENTION 
The crosslinked solid polymer electrolyte of the present invention is 
superior in processability, moldability, mechanical strength, flexibility, 
heat resistance, etc., and the ionic conductivity is remarkably improved. 
Accordingly, the crosslinked solid polymer electrolyte of the present 
invention has an application to electronic apparatuses such as 
large-capacity condenser and display device (e.g. electrochromic display) 
including solid batteries, and an application to antistatic agent for 
plastic materials.