JP2000150308A - Electric double layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve mechanical strength and flexibility of a high polymer solid electrolyte by dissolving an electrolytic salt in a glycidyl compound comprising oligoxyethylene group at side chain, ethyleneoxide, polyether copolymer of specific oxi-silane compound or its crosslinked substance. SOLUTION: An electrical double layer capacitor comprises collector electrodes 1 and 5, electrode layers 2 and 4, and separator layer 3. A high pllymer solid electrolyte applied to the electrical double capacitor is provided by dissolving an electrolytic salt in a glycidyl compound comprising an oligoxyethylene group at side chain, ethyleneoxide, in short an oxi-silane compound comprising an unsaturated part shown with a formula I or II which can be bridged, oxi-silane compound comprising reactive silicon group, or polyther copolymer comprising oxi-silane compound having epoxy group or that having halogen atom or its crosslinked substance. (In formula, R4 and R5 are reactive functional group selected among ethylenic unsaturated group, reactive silicon-contained group, epoxy-contained group, and halogen atom- contained group).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric double layer capacitor using a solid polymer electrolyte having high ionic conductivity.

[0002]

2. Description of the Related Art Polyethylene oxide, cyanoethylated polyvinyl alcohol (Japanese Patent Application Laid-Open No. 1-112719) and the like have been proposed as solid ion conductors for electric double layer capacitors. There is a need for improved ionic conductivity and better mechanical properties. When a polymer solid electrolyte is applied to an electric double layer capacitor, it is desired to have sufficient mechanical strength and flexibility in order to prevent conduction and breakage.

[0003]

Means for Solving the Problems The present inventors have proposed a glycidyl compound (I) having an oligooxyethylene group in a side chain, an ethylene oxide (II), an oxirane compound having an unsaturated moiety capable of crosslinking if necessary, An electrolyte salt is added to a polyether copolymer or a crosslinked product (i) of an oxirane compound having a reactive silicon group, an oxirane compound having an epoxy group or an oxirane compound having a halogen atom (III). The desired polymer solid electrolyte is obtained by dissolving,
Furthermore, they have found that a polymer solid electrolyte is useful for application to an electric double layer capacitor, and have completed the present invention. That is, the present invention has sufficient ionic conductivity,
By using a polymer solid electrolyte having excellent mechanical strength, an electric double layer capacitor excellent in long-term stability can be provided without fear of liquid leakage or the like.

A crosslinked product of a polyether copolymer is used particularly when shape stability at a high temperature is required. Furthermore, in order to improve ion conductivity, an aprotic organic solvent or a plasticizer such as a linear or branched polyalkylene glycol derivative may be added to the non-crosslinked or crosslinked polyether copolymer. Good.

When an aprotic organic solvent or a polyalkylene glycol derivative is mixed, the crystallization of the polymer is suppressed, the glass transition temperature is lowered, and an amorphous phase is formed at a low temperature. Get better.

The present invention relates to (i) (A) a formula (I):

Embedded image [Wherein, R ¹ , R ² and R ³ represent a hydrogen atom or —CH ₂ O (CH ₂ CH ₂ O)
_n R, where n and R may be different between R ¹ , R ² and R ³ . However, all of R ¹ , R ² and R ³ are not hydrogen atoms at the same time. R is selected from an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. And n is 1-12. 5 to 95 mol% of a repeating unit derived from a monomer represented by the formula (II):

Embedded image A repeating unit 95 to 5 derived from a monomer represented by
Mol%, and (C) the formula (III-1) or the formula (III)
-2):

Embedded image

Embedded image [Wherein, R ⁴ and R ⁵ are reactive functional groups selected from an ethylenically unsaturated group, a reactive silicon-containing group, an epoxy-containing group, and a halogen atom-containing group. And polyether copolymers having a repeating unit derived from the reactive group-containing monomer represented by the formula (1) and having a weight-average molecular weight in the range of 10 ⁴ to 10 ⁷ or cross-linking of the copolymer. body,
(Ii) an electrolyte salt and, if necessary, (iii) an aprotic organic solvent and a polymer solid electrolyte comprising a plasticizer selected from the group consisting of linear or branched polyalkylene glycol derivatives. Provided is a used electric double layer capacitor.

The copolymer of the present invention comprises (A) a repeating unit derived from a monomer of the formula (I):

Embedded image [Wherein, R ¹ , R ² and R ³ represent a hydrogen atom or —CH ₂ O (CH ₂ CH ₂ O)
_n R, where n and R may be different between R ¹ , R ² and R ³ . However, all of R ¹ , R ² and R ³ are not hydrogen atoms at the same time. R is selected from an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. And n is 1-12. ] (B) a repeating unit derived from a monomer of formula (II):

Embedded image (C) If necessary, formula (III-1) or formula (III-
The repeating unit derived from the monomer of 2):

Embedded image

Embedded image [Wherein, R ⁴ and R ⁵ are reactive functional groups selected from an ethylenically unsaturated group, a reactive silicon-containing group, an epoxy-containing group, and a halogen atom-containing group. ].

The polymerization method of the polyether copolymer having an oligooxyethylene side chain derived from the monomer (I) (which may have a side chain containing a crosslinkable reactive group) is as follows.
It is described in JP-A-63-154736 of the present applicant.

That is, using a catalyst system mainly comprising organoaluminum, a catalyst system mainly comprising organozinc, a catalyst system comprising an organotin-phosphate ester condensate, etc. as a ring-opening polymerization catalyst, The monomer corresponding to the formula (II) is optionally converted to a compound of the formula (III-1) or the formula (III-2)
By reacting with a monomer corresponding to the above in the presence or absence of a solvent at a reaction temperature of 10 to 80 ° C. with stirring. As the polymerization catalyst, an organotin-phosphate ester condensate catalyst system is particularly preferred in view of the degree of polymerization and the properties of the copolymer to be produced.

The polyether copolymer of the present invention comprises 5 to 95 mol% of the repeating unit (A) and 95 of the repeating unit (B).
-5 mol% and 0-15 mol% of the repeating unit (C). 10 to 95 mol% of the repeating unit (A), particularly 19
９４94 mol%, repeating unit (B) 90-5 mol%, especially 80-5 mol%, and repeating unit (C) 0-10 mol%, particularly 0.1-5 mol% are preferred. When the monomer of the formula (I) and the monomer of the formula (II) are essential components and a crosslinked product is obtained, the compound of the formula (III-1) or the formula (III)
A polyether copolymer is synthesized using the monomer of -2).

When the repeating unit (B) exceeds 95 mol%, the glass transition temperature is increased and oxyethylene chains are crystallized, and as a result, the ionic conductivity of the solid electrolyte is remarkably deteriorated. Will deteriorate the ionic conductivity. It is generally known that the ion conductivity is improved by lowering the crystallinity of polyethylene oxide. However, in the case of the polyether copolymer of the present invention, the effect of improving the ion conductivity is remarkably large.

The molecular weight of the polyether copolymer is as follows:
In order to obtain processability, moldability, mechanical strength and flexibility, the weight average molecular weight is 10 ⁴ to 10 ⁷ , preferably 10 ^{5 to} 5 × 1.
0 of ⁶ scope of what is suitable.

When the weight average molecular weight is less than 10 ⁴ , it is necessary to increase the crosslink density in order to maintain the mechanical strength and to prevent the flow at a high temperature. Decrease. If the weight average molecular weight exceeds 10 ⁷ , problems arise in processability and moldability.

The glass transition temperature of the polyether copolymer is preferably -50.degree. C. or less, and the heat of fusion is preferably 90 J / g or less. The glass transition temperature and the heat of fusion were measured by a differential scanning calorimeter (DSC).

The polyether copolymer of the present invention may be either a block copolymer or a random copolymer. However, the random copolymer is preferred because it has a greater effect of lowering the crystallinity of polyethylene oxide. .

The repeating unit (A) is derived from a monomer of the formula (I). R ¹ , R ² and R ³ in the monomer (I) forming the repeating unit (A) are each a hydrogen atom or —CH ₂ O (CH ₂ CH ₂ O) _n R, all of which are simultaneously hydrogen atoms Never be. n and R may be different or the same between R ¹ , R ² and R ³ . It is preferred that two groups out of R ¹ , R ² and R ³ are the same substituent. R
Is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms,
And a aralkyl group having 7 to 12 carbon atoms. R is preferably an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 4 carbon atoms. The polymerization degree n of the oxyethylene unit in the side chain in the monomer (I) forming the repeating unit (A) is preferably 1 to 12, for example, 1 to 6. Polymerization degree n is 1
If it exceeds 2, the ionic conductivity of the obtained solid electrolyte decreases, which is not preferable.

The repeating unit (B) is derived from a monomer of formula (II) (ie, ethylene oxide). The repeating unit (C) has the formula (III-1) or the formula (II)
It is derived from the monomer of I-2).

The reactive functional group in the repeating unit (C) is (a) an ethylenically unsaturated group, (b) a reactive silicon-containing group, (c) an epoxy-containing group, or (d) a halogen atom-containing group. Is preferred.

The monomer having an ethylenically unsaturated group is represented by the formula (III-a):

Embedded image [Wherein, R ⁶ is a group having ethylenic unsaturation. ]
The oxirane compound represented by is preferred.

The oxirane compounds containing an ethylenically unsaturated group include allyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, α-terpinyl glycidyl ether, cyclohexenylmethyl glycidyl ether, p-vinylbenzyl glycidyl ether, allyl phenyl 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, 3,4-epoxy-1
-Vinylcyclohexene, 1,2-epoxy-5-cyclooctene, glycidyl acrylate, glycidyl methacrylate, glycidyl sorbate, glycidyl cinnamate, glycidyl crotonate, glycidyl-4-hexenoate are used.

Preferably, allyl glycidyl ether,
Allylphenyl glycidyl ether, vinyl glycidyl ether, 3,4-epoxy-1-butene, 3,4-epoxy
There are -1-pentene, 4,5-epoxy-2-pentene, glycidyl acrylate and glycidyl methacrylate.

The monomer having a reactive silicon group forming the repeating unit (C) is represented by the formula (III-b-1):

Embedded image Wherein R ⁷ is a reactive silicon-containing group. Or a formula (III-b-2):

Embedded image [Wherein, R ⁸ is a reactive silicon-containing group. The oxirane compound containing a reactive silicon group represented by the formula (1) is preferable.

The oxirane compound containing a reactive silicon group represented by the formula (III-b-1) is preferably a compound represented by the formula (III-b-1-1) or (III-b-1-)
It is a compound represented by 2).

Embedded image

The oxirane compound having a reactive silicon group represented by the formula (III-b-2) is preferably a compound represented by the formula (III-b-2-1).

Embedded image

Formula (III-b-1-1), Formula (III-
In b-1-2) and formula (III-b-2-1), R ⁹ , R ¹⁰ , and R ¹¹ may be the same or different, but at least one is an alkoxy group, and Is an alkyl group. m represents an integer of 1 to 6.

More preferred examples include those represented by the formula (III-
The monomers represented by b-1-1) include 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 4-glycidoxybutyl Methyltrimethoxysilane and the like can be mentioned.

The monomer represented by the formula (III-b-1-2) includes 3- (1,2-epoxy) propyltrimethoxysilane, 4- (1,2-epoxy) butyltrimethoxysilane, -(1,2-epoxy) pentyltrimethoxysilane and the like.

The monomers represented by the formula (III-b-2-1) include 1- (3,4-epoxycyclohexyl) methylmethyldimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane And the like.

Of these, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane and 4- (1,2-epoxy) butyltrimethoxysilane are particularly preferred.

The monomer having an epoxy group as a reactive functional group, which forms the repeating unit (C), has the formula (III-
c):

Embedded image Wherein R ¹² is a divalent organic group. Oxirane compounds having an epoxy group at both terminals represented by the following formulas are preferred. R ¹² is preferably an organic group composed of an element selected from hydrogen, carbon, and oxygen.

[0031] formula R ¹² groups in (III-c) ^{_{is, -CH 2 -O- (CHA 1 -CHA}} 2 -O) p -CH 2 -, - (CH 2) p -, -CH 2 O-Ph —OCH ₂ — wherein A ¹ and A ² are hydrogen or a methyl group;
h is a phenylene group, and p is a number from 0 to 12. ]
It is preferred that

The monomers having an epoxy group as a reactive functional group are represented by the following formulas (III-c-1) and (III-c-2)
And compounds represented by (III-c-3).

Embedded image In the above (III-c-1), (III-c-2) and (III-c-3), A ¹ and A ² are a hydrogen atom or a methyl group, and p represents a number of 0 to 12.

The monomer represented by the formula (III-c-1) includes 2,3-epoxypropyl-2 ', 3'-epoxy-2'-
Methyl propyl ether, ethylene glycol-2,3-
Epoxypropyl-2 ', 3'-epoxy-2'-methylpropyl ether, and diethylene glycol-2,3-epoxypropyl-2', 3'-epoxy-2'-methylpropyl ether, and the like.

The monomer represented by the formula (III-c-2) includes 2-methyl-1,2,3,4-diepoxybutane,
Methyl-1,2,4,5-diepoxypentane and 2-methyl-1,2,5,6-diepoxyhexane and the like.

The monomer represented by the formula (III-c-3) includes hydroquinone-2,3-epoxypropyl-2 ', 3'-
Epoxy-2'-methylpropyl ether, and catechol-2,3-epoxypropyl-2 ', 3'-epoxy-2'-methylpropylether, and the like.

2,3-epoxypropyl-2 ', 3'-epoxy-2'-methylpropylether, ethylene glycol-
2,3-epoxypropyl-2 ', 3'-epoxy-2'-methylpropylether, 2-methyl-1,2,3,4-diepoxybutane and hydroquinone-2,3-epoxypropyl-
2 ', 3'-Epoxy-2'-methylpropyl ether is particularly preferred.

The monomer having a halogen atom is represented by the formula (II)
Id):

Embedded image [Wherein, R ¹³ is a group having a halogen atom. ] Is preferable.

The oxirane compound containing a halogen atom includes epichlorohydrin, epibromohydrin, epiiodohydrin and the like.

As a method for crosslinking the copolymer having an ethylenically unsaturated group used in the present invention, a radical initiator selected from organic peroxides, azo compounds and the like, and active energy rays such as ultraviolet rays and electron beams are used. Can be Furthermore, a crosslinking agent having silicon hydride can be used.

As the organic peroxide, ketone peroxide, peroxyketal, hydroperoxide,
Dialkyl peroxide, diacyl peroxide,
Peroxyesters and the like usually used for crosslinking are used, and 1,1-bis (t-butylperoxy) -3,
3,5-trimethylcyclohexane, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, benzoyl peroxide And the like. The amount of the organic peroxide to be added varies depending on the type of the organic peroxide.
It is in the range of 10% by weight.

As the azo compound, those usually used for cross-linking such as azonitrile compound, azoamide compound and azoamidine compound are used, and 2,2′-azobisisobutyronitrile, 2,2′-azobis ( 2-methylbutyronitrile), 2,2'-azobis (4-methoxy-2,4
-Dimethylvaleronitrile), 2,2-azobis (2-methyl
-N-phenylpropionamidine) dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,
2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2'-azobis (2-methylpropane), 2,2'-azobis [2- (hydroxymethyl) propionitrile And the like. The amount of the azo compound added varies depending on the type of the azo compound, but is usually within the range of 0.1 to 10% by weight of the polyether copolymer.

Monomers suitable for crosslinking by irradiation with active energy rays such as ultraviolet rays are glycidyl acrylate,
Glycidyl methacrylate and glycidyl cinnamate are particularly preferred. As sensitizing aids, ethoxyphenones such as diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one and phenyl ketone; benzoin ethers such as benzoin and benzoin methyl ether; benzophenone; Benzophenones such as phenylbenzophenone; thioxanthones such as 2-isopropylthioxanthone and 2,4-dimethylthioxanthone; 3-sulfonylazidebenzoic acid;
Azides such as sulfonylazidebenzoic acid and the like can be optionally used.

As crosslinking aids for these crosslinking reactions, ethylene glycol diacrylate, ethylene glycol dimethacrylate, oligoethylene glycol diacrylate, oligoethylene glycol dimethacrylate, allyl methacrylate, allyl acrylate, diallyl maleate, triallyl isocyanurate, Maleimide, phenylmaleimide, maleic anhydride and the like can be optionally used.

As the cross-linking agent having silicon hydride for cross-linking the ethylenically unsaturated group, a compound having at least two silicon hydrides is 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).

[0045]

Embedded image

In the formulas (a-1) to (a-3), R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ are each a hydrogen atom Alternatively, it represents an alkyl group or an alkoxy group having 1 to 12 carbon atoms, and q and r represent integers. r
≧ 2, q ≧ 0, and 2 ≦ q + r ≦ 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) is used.

Embedded image However, in the formula (b-1), R ³⁰ , R ³¹ , R ³² , R ³³ and R ³⁴ represent a hydrogen atom or an alkyl or alkoxy group having 1 to 12 carbon atoms, and s and t represent integers . t
≧ 2, s ≧ 0, and 2 ≦ s + t ≦ 100.

Examples of the catalyst for the hydrosilylation reaction include:
Examples thereof include transition metals such as palladium and platinum or compounds and complexes thereof. Also, peroxides, amines and phosphines are used. The most common catalysts include dichlorobis (acetonitrile) palladium (II), chlorotris (triphenylphosphine) rhodium (I), chloroplatinic acid.

As a method of crosslinking a copolymer containing a reactive silicon group, crosslinking can be performed by reacting a reactive silicon group with water. To increase reactivity, dibutyltin dilaurate, dibutyltin malate, dibutyltin diacetate, Tin compounds such as tin octylate and dibutyltin acetylacetonate, titanium compounds such as tetrabutyl titanate and tetrapropyl titanate, aluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, and diisopropoxyaluminum ethylacetoacetate Organometallic compounds, or butylamine, octylamine,
Amine compounds such as laurylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetraamine, cyclohexylamine, benzylamine, diethylaminopropylamine, guanine, and diphenylguanine may be used as the catalyst. .

Polyamines, acid anhydrides and the like are used as a method for crosslinking a copolymer containing a side chain epoxy group.
As polyamines, diethylenetriamine, dipropylenetriamine, triethylenetetramine, tetraethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine, hexamethylenediamine, N-aminoethylpiperazine, bis-aminopropylpiperazine, Aliphatic polyamines such as trimethylhexamethylenediamine, isophthalic dihydrazide, 4,4'-diaminodiphenyl ether, diaminodiphenylsulfone, m-phenylenediamine, 2,4-toluylenediamine, m-toluylenediamine, o-toluylenediamine And aromatic polyamines such as xylylenediamine. The amount of addition varies depending on the type of polyamine, but is usually in the range of 0.1 to 10% by weight of the polyether copolymer.

Examples of the acid anhydrides include maleic anhydride, dodecenylsuccinic anhydride, chlorendexic anhydride, phthalic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetramethylene maleic anhydride, tetrahydrohydric anhydride Examples thereof include phthalic anhydride, methyltetrahydrophthalic anhydride, and trimellitic anhydride. The amount added depends on the type of acid anhydride,
Usually, it is in the range of 0.1 to 10% by weight of the polyether copolymer. Accelerators may be used for these crosslinks, and phenol, cresol, resorcin, pyrogallol, nonylphenol, 2,4,6
-Tris (dimethylaminomethyl) phenol, etc., and benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, 2- (dimethylaminoethyl) phenol, dimethylaniline And 2-ethyl-4-methylimidazole. The amount added depends on the accelerator, but is usually in the range of 0.1 to 10% by weight of the crosslinking agent.

As a method for crosslinking a halogen atom-containing copolymer, crosslinking agents such as polyamines, mercaptoimidazolines, mercaptopyrimidines, thioureas, and polymercaptans are used. As polyamines,
Triethylenetetramine, hexamethylenediamine and the like can be mentioned. Examples of mercaptoimidazolines include 2-mercaptoimidazoline, 4-methyl-2-mercaptoimidazoline and the like. Examples of mercaptopyrimidines include 2-mercaptopyrimidine, 4,6-dimethyl-2-mercaptopyrimidine and the like. Examples of thioureas include ethylene thiourea and dibutyl thiourea. Examples of the polymercaptans include 2-dibutylamino-4,6-dimethylcapto-s-triazine, 2-phenylamino-4,6-dimercaptotriazine and the like. The amount of the crosslinking agent varies depending on the type of the crosslinking agent, but is usually in the range of 0.1 to 30% by weight of the polyether copolymer.

It is effective to further add a metal compound serving as an acid acceptor to the solid polymer electrolyte of the present invention from the viewpoint of the thermal stability of the halogen-containing polymer. Examples of the metal oxide serving as such an acid acceptor include oxides, hydroxides, carbonates, carboxylates, silicates, borates, phosphites, and oxides of Group II metals of the periodic table. Group VIa metal oxides, basic carbonates, basic carboxylate salts, basic phosphites, basic sulfites, tribasic sulfates, and the like.

Specific examples include magnesia, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, quicklime, slaked lime, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, calcium phthalate, and phosphorus phosphite. Magnesium phosphate, calcium phosphite, zinc white, tin oxide, litharge, lead tan, lead white, dibasic lead phthalate, dibasic lead carbonate, tin stearate, basic lead phosphite, basic tin phosphite , Basic lead sulfite, tribasic lead sulfate and the like. The amount of the metal compound serving as the acid acceptor varies depending on the kind, but is usually 0.1 to 30% by weight of the polyether copolymer.
Range.

The electrolyte salt compound used in the present invention may be any as long as it is soluble in the polyether copolymer of the present invention or a crosslinked product of the copolymer, but the following compounds are preferred. That is, metal cations, ammonium ions, amidinium ions, and cations selected from guanidium ions, chloride ions, bromine ions, iodine ions, perchlorate ions, thiocyanate ions, tetrafluoroborate ions, Nitrate ion, As
F ₆ ⁻ , PF ₆ ⁻ , stearyl sulfonate ion, octyl sulfonate ion, dodecylbenzene sulfonate ion, naphthalene sulfonate ion, dodecylnaphthalene sulfonate ion, 7,7,8,8-tetracyano-p-quinodimethane Ion, X ¹ SO ₃ ⁻ , [(X ¹ SO ₂ ) (X ² SO ₂ )
N] ^- , [(X ¹ SO ₂ ) (X ² SO ₂ ) (X ³ SO ₂ ) C] ^- , and
[(X ¹ SO ₂ ) (X ² SO ₂ ) YC] ^- . However, X ¹ , X ² , X ³ ,
And Y are electron-withdrawing groups. More preferably, X ¹ ,
X ² and X ³ are each independently a perfluoroalkyl group or a perfluoroaryl group having 1 to 6 carbon atoms, and Y is a nitro group, a nitroso group, a carbonyl group, a carboxyl group, or a cyano group. X ¹ , X ² , and X
³ may be the same or different.

As the metal cation, a cation of a transition metal can be used. Preferably Mn, Fe, Co, N
A cation of a metal selected from i, Cu, Zn and Ag metals is used. Also, Li, Na, K, Rb, Cs,
Preferable results are obtained by using a cation of a metal selected from Mg, Ca and Ba metals. It is free to use two or more of the aforementioned compounds as electrolyte salt compounds.

In the present invention, the amount of the electrolyte salt compound used is the ratio to the total number of moles of oxygen atoms in the ether including the main chain and side chains of the polyether copolymer, that is, the molar ratio (the number of moles of the electrolyte salt compound). ) / (Total number of moles of oxygen atoms in ether of polyether copolymer) is 0.000.
The range is from 1 to 5, preferably from 0.001 to 0.5. If this value exceeds 5, the workability, moldability, mechanical strength and flexibility of the obtained solid electrolyte are reduced, and the ionic conductivity is also reduced.

The plasticizer (iii) is an aprotic organic solvent or a derivative of a linear or branched polyalkylene glycol. As the aprotic organic solvent, aprotic ethers and esters are preferable. Specifically, propylene carbonate, γ-butyrolactone, butylene carbonate, ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, 1,2-dimethoxyethane,
1,2-dimethoxypropane, 3-methyl-2-oxazolidone, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4,4-methyl-1,3-dioxolane, tert-butyl ether, iso-butyl ether,
1,2-ethoxymethoxyethane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, ethylene glyme, ethylene diglyme, methyl tetraglyme, Methyl triglyme, methyl diglyme, methyl formate, methyl acetate, methyl propionate and the like can be mentioned, and a mixture of two or more of these may be used.

Particularly preferred are propylene carbonate, γ-butyrolactone, butylene carbonate and 3-methyl-2-oxazoline. Triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether,
Tetraethylene glycol diethyl ether is also a particularly preferred organic solvent.

The linear or branched polyalkylene glycol derivative has a number average molecular weight of 200 to 50.
Those obtained from a polyalkylene glycol of 00 are preferred. Examples of the polyalkylene glycol include polyethylene glycol and polypropylene glycol, and derivatives thereof include an ester derivative, an ether derivative, and a metal salt having an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 3 to 8 carbon atoms.

Among the derivatives, ether derivatives include diethers such as dimethyl ether, diethyl ether, dipropyl ether and diallyl ether, and ester derivatives include polyalkylene glycol dimethacrylate (eg, polyethylene glycol dimethacrylate) and polyether. Diesters such as alkylene glycol diacetate (eg, polyethylene glycol diacetate) and polyalkylene glycol diacrylate (eg, polyethylene glycol diacrylate) can be mentioned. Examples of the metal salt include sodium, lithium and dialkylaluminum salts of polyalkylene glycol.

The mixing ratio of the plasticizer is arbitrary, but is 0 to 2000 parts by weight, preferably 1 to 2000 parts by weight, for example, 10 to 1 part by weight, per 100 parts by weight of the polyether copolymer.
000 parts by weight, especially 10 to 500 parts by weight.

The method for producing the solid polymer electrolyte of the present invention is not particularly limited, but usually, the polyether copolymer (i), the electrolyte salt (ii), and if necessary, the plasticizer (iii) are mechanically added. What is necessary is just to mix. In the case of the polyether copolymer (i) requiring crosslinking, it may be produced by a method of mechanically mixing the components and then crosslinking. Alternatively, after crosslinking, the polymer is immersed in an organic solvent containing the electrolyte salt (ii) and, if necessary, a plasticizer (iii) for a long time,
The electrolyte salt (ii) and, if necessary, a plasticizer (iii) may be impregnated.

Electrolyte salt (ii) and plasticizer (iii)
Is not particularly limited, and the electrolyte salt (ii) and the plasticizer (ii) can be mixed with the polyether copolymer (i).
A method in which the polyether copolymer (i) is immersed in an organic solvent containing i) for a long time to impregnate it, and the electrolyte salt (ii) and the plasticizer (iii) are mechanically mixed with the polyether copolymer (i). A method of dissolving the polyether copolymer (i), the electrolyte salt (ii) and the plasticizer (iii) in an organic solvent and mixing them, and dissolving the polyether copolymer (i) in another solvent once. And a method of mixing the electrolyte salt (ii) and the plasticizer (iii). The organic solvent (eg, acetonitrile) used for the mixing is removed after the production of the solid polymer electrolyte.

As means for mechanically mixing, various kneaders, open rolls, extruders and the like can be arbitrarily used. When a radical initiator is used in the cross-linking reaction of the ethylenically unsaturated group, the cross-linking reaction is completed in a temperature of 10 ° C. to 200 ° C. for 1 minute to 20 hours. When using energy rays such as ultraviolet rays, a sensitizer is generally used. Usually, 0.1 second to 1 under the temperature condition of 10 ° C. to 150 ° C.
The crosslinking reaction is completed in a time. In the crosslinking reaction of the reactive silicon-containing group, the amount of water used in the reaction is not particularly limited, since the reaction easily occurs even by moisture. When a polyamine or an acid anhydride is used in the crosslinking reaction of the epoxy group, the crosslinking reaction is completed at a temperature of 10 to 200 ° C. for 10 minutes to 20 hours.

The polymer solid electrolyte shown in the present invention is excellent in mechanical strength and flexibility, and can easily be made into a thin film-shaped solid electrolyte by utilizing its properties. An electric double layer capacitor is manufactured using a solid polymer electrolyte.

The electric double layer capacitor has one separator layer, two electrode layers (conductive layers) located on both sides of the separator layer, and two current collecting electrodes located outside the electrode layers. The separator layer, the electrode layer, and the collecting electrode may be protected by a protective layer. An example of the protective layer is a resin such as an epoxy resin. The current collecting electrode is connected to a lead wire, for example, a copper wire.

The separator layer may be composed of a solid polymer electrolyte alone or a combination of a solid polymer electrolyte and a porous membrane. Examples of the porous membrane are polyethylene and polypropylene. The thickness of the separator layer may be, for example, 15 to 500 μm.

The electrode layer is made of an electrode material (porous conductive material)
And a solid polymer electrolyte. As the electrode material, those having a large surface area such as activated carbon and porous metal are preferable. The raw material of the activated carbon is not particularly limited. Examples of the raw material of the activated carbon include a natural organic polymer, a synthetic organic polymer and pitch. The activated carbon used in the present invention may have any shape such as fibrous or powdery. The thickness of one electrode layer may be, for example, 20 to 500 μm. The weight ratio between the electrode material and the solid polymer electrolyte in the electrode layer may be, for example, 5/95 to 95/5. The collecting electrode may be made of a metal, for example, aluminum, nickel, or the like. The thickness of one current collecting electrode is, for example, 15 to 10
It may be 0 μm.

When the polymer solid electrolyte of the present invention is used for an electric double layer capacitor, the polymer solid electrolyte has excellent ionic conductivity and excellent mechanical strength, so that it is as good as when an electrolyte solution is used. Charging and discharging can be performed. In addition, since the electrolyte is solid, long-term stability is improved without fear of liquid leakage or the like. In order to provide the polymer solid electrolyte of the present invention on an electrode, if the electrode material is a powder, after mixing the powdered electrode material with a solution of the polymer solid electrolyte, the solvent is removed, or the electrode material is removed. When is fibrous, the solvent may be removed after impregnating the fibrous electrode material with the polymer solid electrolyte solution. An electric double layer capacitor can be obtained by mixing a polymer solid electrolyte with an electrode material in this way and inserting a separator (for example, a polymer solid electrolyte plate) between two molded articles.

As a method for producing the electric double layer capacitor of the present invention, there is a method of sandwiching a polymer solid electrolyte sheet with an activated carbon sheet impregnated with the polymer solid electrolyte. If both electrodes are short-circuited, a porous material impregnated with a solid polymer electrolyte may be used as the separator.

FIG. 1 is a sectional view of a preferred embodiment of the electric double layer capacitor of the present invention. The electric double layer capacitor has current collecting electrodes 1 and 5, electrode layers (or conductive layers) 2 and 4, and a separator layer 3. The collecting electrode 1 is connected to a lead wire 6, and the collecting electrode 2 is connected to a lead wire 7. The surroundings of the current collecting electrodes 1 and 5, the electrode layers 2 and 4, and the separator layer 3 are protected by a protective layer 8.

[0073]

The present invention will be described below in detail with reference to examples. Properties were measured as follows. After performing constant voltage charging at a voltage of 2.5 V of the capacitor,
Was discharged under the condition of a load resistance of 1 kΩ to the voltage of 電 気, and the capacity of the electric double layer capacitor was measured.

The monomer-converted composition and the molecular weight of the copolymer were determined by ¹ H NMR spectrum. For the measurement of the molecular weight of the copolymer, gel permeation chromatography was measured, and the molecular weight was calculated in terms of standard polystyrene. Gel permeation chromatography measurement was performed using Shimadzu Corporation's RID-6A measuring instrument, Showa Denko KK columns Showdex KD-807, KD-806, KD-806M and K.
D-803 and solvent DMF (dimethylformamide)
At 60 ° C.

Glass transition temperature and heat of fusion The glass transition temperature and the heat of fusion were measured using a differential scanning calorimeter DSC8230B manufactured by Rigaku Corporation in a nitrogen atmosphere at a temperature range of -100 to 80 ° C and a heating rate of 10 ° C / min. It was measured.

Preparation Example of Catalyst In a three-necked flask equipped with a stirrer, a thermometer and a distillation apparatus, 10 g of tributyltin chloride and 35 g of tributylphosphate were placed, and stirred at 250 ° C. under a nitrogen stream.
For 20 minutes to distill off the distillate to obtain a solid organic tin-phosphate ester condensate as a residue. In the following polymerization reaction, the obtained organotin-phosphate condensate was used as a catalyst.

Example 1 The inside of a three-liter glass four-necked flask was replaced with nitrogen, and as a catalyst, 0.5 g of an organotin-phosphate ester condensed substance and 17 g of allyl glycidyl ether adjusted to 10 ppm or less of water were added. Glycidyl ether compound (I-
a):

Embedded image 300 g and 1,000 g of hexane as a solvent were charged, and 75 g of ethylene oxide was observed while monitoring the polymerization rate of the glycidyl ether compound by gas chromatography.
Added sequentially. The polymerization reaction was stopped with methanol. After removing the polymer by decantation, it is
The polymer was dried at 0 ° C. for 20 hours and further under reduced pressure at 45 ° C. for 8 hours to obtain 330 g of a polymer.

Glycidyl ether compound (Ia): ethylene oxide: allyl glycidyl ether = 32: 6
5: 3 mol%, glass transition temperature -71 ° C, weight average molecular weight by gel permeation chromatography is 9
80,000, the heat of fusion was 8 J / g. Polyether copolymer 50 obtained in acetonitrile (250 g)
g, propylene carbonate 15 g, lithium borofluoride 7 g, benzoyl oxide 0.75 g as a crosslinking agent
Was mixed. An activated carbon fiber sheet provided with an aluminum spray electrode (thickness: 50 μm) was immersed in this acetonitrile solution, and the solution was completely contained in the activated carbon fiber sheet. Thereafter, the acetonitrile was volatilized, and crosslinking was performed at 100 ° C. for 3 hours while removing the solvent, to obtain a composite sheet in which the activated carbon fiber sheet was impregnated with the crosslinked polymer solid electrolyte. The obtained composite sheet was vacuum dried at 40 ° C. for 24 hours. In the composite sheet, the thickness of the activated carbon fiber / polymer solid electrolyte layer is 100 μm, and the weight ratio of the activated carbon fiber to the polymer solid electrolyte is 50/50.
Met.

A separator (thickness: 100 μm) made of porous polypropylene impregnated with a polymer solid electrolyte (thickness: 100 μm) between the two activated carbon fiber / polymer solid electrolyte composite sheets thus obtained. These were press-bonded with each other with the weight ratio of (porous polypropylene: 50/50). After cutting this sheet into a size of 1 cm x 1 cm, copper conductors were attached to both aluminum electrodes,
An element was manufactured. Thereafter, a protective layer having a thickness of 1 mm was applied to the element by applying an epoxy resin to the surface.
The electric double layer capacitor as shown in FIG. After performing constant voltage charging at a voltage of 2.5 V, discharging was performed under a condition of a load resistance of 1 kΩ to a voltage of 1.0 V, and the capacity of the electric double layer capacitor was measured. The capacity of this capacitor was 0.1 F, and the capacity converted to 1 g of activated carbon was 10 F / g.

Example 2 Glycidyl ether compound (Ib):

Embedded image Polymerization was carried out in the same manner as in Example 1 using an organotin-phosphate ester condensate catalyst system, except that ethylene oxide and 3,4-epoxy-1-butene were used. The polymer composition of the obtained terpolymer was a glycidyl ether compound (I-
b): Ethylene oxide: 3,4-epoxy-1-butene =
12: 87: 1 mol%, the glass transition temperature was -71 ° C, the weight average molecular weight was 1.1 million, and the heat of fusion was 45 J / g.

After mixing 50 g of the obtained polyether copolymer, 15 g of propylene carbonate, 7 g of lithium borofluoride and 0.80 g of azobisisobutyronitrile as a cross-linking agent in acetonitrile (250 g), the mixture was mixed at 90 ° C.
For 7 hours while removing the solvent. Thereafter, the same operation as in Example 1 was performed to manufacture an electric double layer capacitor. The capacity of the capacitor was 0.1 F, and the capacity converted to 1 g of activated carbon was 9 F / g.

[0082]

The electric double layer capacitor using a polymer solid electrolyte which is excellent in workability, moldability, mechanical strength, flexibility and heat resistance, and has remarkably improved ionic conductivity has a high efficiency. It can transport ions well and has high capacitor capacity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electric double layer capacitor obtained in Example 1.

[Explanation of symbols]

1, 5: current collecting electrode, 2, 4: electrode layer, 3: separator layer, 6, 7: lead wire, 8: protective layer.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsuhito Miura 9 Daitakasu-cho, Amagasaki-shi, Hyogo Daiso Corporation (72) Inventor Hiroki Higobashi 9 Daitakasu-cho, Amagasaki-shi, Hyogo Daiso Corporation Inside

Claims (10)

[Claims] (I) (A) Formula (I): [Wherein, R ¹ , R ² and R ³ represent a hydrogen atom or —CH ₂ O (CH ₂ CH ₂ O)
_n R, where n and R may be different between R ¹ , R ² and R ³ . However, all of R ¹ , R ² and R ³ are not hydrogen atoms at the same time. R is selected from an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. And n is 1-12. 5 to 95 mol% of a repeating unit derived from a monomer represented by the formula (II): A repeating unit 95 to 5 derived from a monomer represented by
Mol%, and (C) the formula (III-1) or the formula (III)
-2): embedded image Embedded image [Wherein, R ⁴ and R ⁵ are reactive functional groups selected from an ethylenically unsaturated group, a reactive silicon-containing group, an epoxy-containing group, and a halogen atom-containing group. And polyether copolymers having a repeating unit derived from the reactive group-containing monomer represented by the formula (1) and having a weight-average molecular weight in the range of 10 ⁴ to 10 ⁷ or cross-linking of the copolymer. body,
And (ii) an electric double layer capacitor using a polymer solid electrolyte comprising an electrolyte salt. 2. The polymer solid electrolyte further comprises (iii)
The electric double layer capacitor according to claim 1, comprising an aprotic organic solvent and a plasticizer selected from the group consisting of a linear or branched polyalkylene glycol derivative. 3. The electric double layer capacitor according to claim 1, wherein activated carbon is used for both electrodes. 4. The electric double layer capacitor according to claim 1, wherein the weight average molecular weight of the polyether copolymer is in the range of 10 ^{5 to} 5 × 10 ⁶ . 5. A polyether copolymer comprising 10 to 95 mol% of the repeating unit (A) and 90 to 5 of the repeating unit (B).
The electric double layer capacitor according to any one of claims 1 to 3, comprising mol% and a repeating unit (C) of 0 to 10 mol%. 6. The compound of the formula (I) wherein R has 1 to 3 carbon atoms.
The electric double layer capacitor according to any one of claims 1 to 3, which is an alkyl group or an alkenyl group having 2 to 4 carbon atoms. 7. The reactive group-containing monomer is allyl glycidyl ether, allyl phenyl glycidyl ether, vinyl glycidyl ether, 3,4-epoxy-1-butene, 3,4-epoxy-1-pentene, 4.5. The electric double layer capacitor according to any one of claims 1 to 3, which is a monomer selected from -epoxy-2-pentene, glycidyl acrylate, and glycidyl methacrylate. 8. The electric double layer capacitor according to claim 1, wherein the reactive group-containing monomer is a monomer selected from epibromohydrin, epiiodohydrin, and epichlorohydrin. . 9. The method according to claim 1, wherein the reactive group-containing monomer is a monomer selected from γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropylmethyldimethoxysilane. Electric double layer capacitor. 10. The reactive group-containing monomer is 2,3-epoxypropyl-2 ′, 3′-epoxy-2′-methylpropylether, ethylene glycol-2,3-epoxypropyl-
2 ', 3'-epoxy-2'-methylpropyl ether, 2-methyl-1,2,3,4-diepoxybutane, hydroquinone-
2. A monomer selected from 2,3-epoxypropyl-2 ', 3'-epoxy-2'-methylpropylether.
4. The electric double layer capacitor according to any one of claims 1 to 3.