JP2003317540A - Resin composition for polymer solid electrolyte, polymer solid electrolyte and polymer cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polymer solid electrolyte which has a good film strength, high ion conductivity and excellent processability. <P>SOLUTION: This resin composition for polymer solid electrolytes is characterized by comprising a curable polymer (A) of 0.5 to 9.0 weight % having a specific structure, a plasticizer (B), and an electrolyte (C). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin composition for polymer solid electrolyte containing a copolymer having a cyano group and a specific functional group in a side chain, a photopolymerization initiator, a plasticizer and an electrolyte, and a polymer. It relates to a solid electrolyte and a polymer battery.

[0002] Conventionally, as an electrolyte constituting an electrochemical device such as a battery, a capacitor or a sensor, a solution or paste is used from the viewpoint of ionic conductivity, but there is a risk of damage to equipment due to liquid leakage. In addition, since a separator impregnated with the electrolytic solution is required, there are problems such as a limitation in miniaturization and thinning of the device. On the other hand, a product using a solid electrolyte does not have such a problem and can be easily thinned. Furthermore, the solid electrolyte is also excellent in heat resistance and is advantageous in the manufacturing process of products such as batteries.

In particular, the one using a solid electrolyte containing a polymer as a main component has an advantage that the flexibility of the battery is increased and it can be processed into various shapes as compared with an inorganic substance. However, what has been studied so far has a problem that the extraction current is small because the ionic conductivity of the solid polymer electrolyte is low. For example, a method of applying a specific alkali metal salt to a mixture of epichlorohydrin-based rubber and a polyethylene glycol derivative having a low molecular weight and applying it to a polymer solid electrolyte (JP-A-2-235957), or crosslinking by a polyethylene glycol diacrylate polymerization reaction Although a method (Japanese Patent Laid-Open No. 62-285954) and the like have been proposed, there is a problem that the strength of the film is not sufficient and a support is required. Therefore, the film strength, the ionic conductivity, and the adhesion to the electrode are required. Further improvement is desired in the balance of the above.

Further, in recent years, an electric double layer capacitor in which a carbon material having a large specific surface area such as activated carbon or carbon black is used as a polarizable electrode and an ion conductive solution is arranged between them has been widely used for a memory backup power source or the like. . For example, Japanese Patent Application Laid-Open No. 63-244570 discloses a capacitor using Rb ₂ Cu ₃ I ₃ Cl ₇ having high electric conductivity as an inorganic solid electrolyte.
In "Functional Material", February 1989, p. 33, a capacitor using a carbon-based polarizable electrode and an organic electrolytic solution is described. However, current electric double layer capacitors that use electrolyte solutions are prone to long-term use and reliability because liquid leakage to the outside of the capacitor is likely to occur during abnormal conditions such as long-term use or when high voltage is applied. There is a problem with sex. On the other hand, there is a problem that the decomposition voltage of the conventional inorganic ion conductive material is low and the output voltage is low.

The solid polymer electrolyte layer in the battery and the capacitor is responsible only for ion migration, and the thinner it is, the smaller the volume of the battery and the whole capacitor can be made, and the higher the energy density of the battery and the capacitor can be made. Further, by thinning the polymer solid electrolyte layer, the electric resistance of the battery and the capacitor can be reduced, the extraction current and the charging current can be increased, and the power density of the battery can be improved. Also, corrosion of ions, especially alkali metal ions, is unlikely to occur, and cycle life is improved. Therefore,
There has been a demand for a polymer solid electrolyte having a high ionic conductivity which has a film strength as good as possible and can be made into a thin film.

[0006]

The present invention has a strength that does not require a support even when formed into a thin film of about several tens of μm, has high ionic conductivity at room temperature and low temperature, and is excellent in workability. An object of the present invention is to provide a resin composition for polymer solid electrolyte, which does not leak electrolyte solution, and a polymer battery using the same.

[0007]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have aimed to use a composition containing a specific copolymer and a composition containing a plasticizer and an electrolyte. I found that I can achieve. further,
By using a polymer solid electrolyte obtained by curing this composition in a battery, it was found that the above problems of ionic conductivity, membrane strength, processability, etc. were improved, and the present invention was completed.

That is, according to the present invention, (1) a curable polymer (A) having a cyano group and an ethylenically unsaturated double bond in a side chain and having an ethylenically unsaturated double bond equivalent of 850 or less. A resin composition for a polymer solid electrolyte, containing a plasticizer (B) and an electrolyte (C), (2)
0.5% by weight to 9.0% by weight of the curable polymer (A), the resin composition for polymer solid electrolyte according to the above (1), (3) 0.5% by weight ~ 5.0% by weight
(4) The resin composition for polymer solid electrolyte as described in (1) above, which contains the curable polymer (A).
0.5% to 3.0% by weight of a curable polymer (A) is contained, the resin composition for polymer solid electrolyte according to the above (1), (5) a photopolymerization initiator ( The resin composition for polymer solid electrolyte according to any one of (1) to (4) above, which comprises D), and (6) a photopolymerization initiator (D).
Of the resin composition for polymer solid electrolyte according to (5), which has a maximum molar absorption coefficient of 50 or more at a wavelength of 350 to 450 nm, and (7) to (1) or (1) containing a thermal polymerization initiator (E). The resin composition for polymer solid electrolyte according to any one of (4), (8) a thermal polymerization initiator (E),
The resin composition for polymer solid electrolyte according to (7) above, which has a 10-hour half-life temperature of 10 ° C. or higher, (9) the electrolyte (C) is an alkali metal salt, a quaternary ammonium salt, a quaternary phosphonium salt, and The resin composition for polymer solid electrolyte according to any one of (1) to (8) above, which is at least one selected from transition metal salts, (10) any of (1) to (9) above A solid polymer electrolyte comprising a cured product of the resin composition for a solid polymer electrolyte according to one item, (11) a solid polymer electrolyte according to (10) above in the form of a sheet, (12) above (9) or A polymer battery comprising the polymer solid electrolyte according to (11).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The resin composition for a solid polymer electrolyte of the present invention has a cyano group and an ethylenically unsaturated double bond in its side chain, and its ethylenically unsaturated double bond equivalent is 850 or less. It is characterized by containing a certain curable polymer (A), a plasticizer (B) and an electrolyte (C).

The curable polymer (A) used in the present invention comprises a compound having a cyano group and an ethylenically unsaturated double bond, and
After obtaining a copolymer of a compound having one ethylenically unsaturated double bond and one epoxy group in the molecule, it is reacted with a compound having one unsaturated double bond and one carboxyl group in one molecule. Can be obtained. The curable polymer (A) preferably has a molecular weight of about 1,000 to 1,000,000, and more preferably 2,000 to 500,000. The ethylenically unsaturated double bond equivalent of the curable polymer (A) used in the present invention is 10 in order to obtain good curability.
00 or less is preferable, and 850 or less is particularly preferable.

A compound having a cyano group and an ethylenically unsaturated double bond and one ethylenically unsaturated double bond in one molecule.
And a compound having one epoxy group are, for example, cyanomethyl (meth) acrylate, cyanoethyl (meth) acrylate, cyanopropyl (meth) acrylate, cyanobutyl (meth) acrylate, cyanohexyl (meth) acrylate, and other cyano compounds. A compound having a group and an ethylenically unsaturated double bond, for example, one ethylenically unsaturated double bond and epoxy in one molecule of glycidyl (meth) acrylate, (meth) acryloylmethylcyclohexene oxide, vinylcyclohexene oxide, etc. It is obtained by copolymerizing a compound having one group. These compounds may be copolymerized with one kind or two or more kinds, and include 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylic acid, styrene, phenoxyethyl (meth) acrylate, benzyl (meth). ) One or more ethylenically unsaturated monomers such as acrylate and α-methylstyrene may be copolymerized. The amount of the compound having one ethylenically unsaturated double bond and one epoxy group in one molecule is:
The amount is preferably 0.1 to 90% by weight, particularly preferably 1 based on the total amount of unsaturated monomers used for producing the copolymer (A).
~ 50% by weight.

These polymers can be obtained by known polymerization methods such as solution polymerization and emulsion polymerization.
Explaining the case of using solution polymerization, the ethylenically unsaturated monomer mixture, in a suitable organic solvent, for example,
A polymerization initiator such as a peroxide such as benzoyl peroxide or an azo compound such as azobisisobutyronitrile is added, and the mixture is polymerized by heating and stirring under a nitrogen stream, preferably at 50 to 100 ° C. As the organic solvent, for example,
Ethanol, propanol, isopropanol, butanol, isobutanol, 2-butanol, hexanol, alcohols such as ethylene glycol, methyl ethyl ketone, ketones such as cyclohexanone, toluene,
Aromatic hydrocarbons such as xylene, cellosolves such as cellosolve and butyl cellosolve, carbitols such as carbitol and butyl carbitol, propylene glycol alkyl ethers such as propylene glycol methyl ether, and polypyrrole such as dipropylene glycol methyl ether. Pyrene glycol alkyl ethers, ethyl acetate, butyl acetate, cellosolve acetate, acetic acid esters such as propylene glycol monomethyl acetate, lactate esters such as ethyl lactate and butyl lactate, dialkyl glycol ethers, carbonates such as ethylene carbonate and propylene carbonate Etc.
These organic solvents may be used alone or in combination. The reaction temperature is 40 to 150 ° C., and the reaction time is 1 to 50.
Time is preferred. For example, glycidyl methacrylate is a compound having one ethylenically unsaturated double bond and one epoxy group in one molecule, acrylic acid is a compound having one unsaturated double bond and one carboxyl group in one molecule, In order to obtain 100 parts of the curable polymer (A) having an ethylenically unsaturated double bond of 850, it is advisable to use at least 16.8 parts of glycidyl methacrylate and 8.2 parts of acrylic acid.

Next, a compound having one unsaturated double bond and one carboxyl group in each molecule (for example, (meth))
Acrylic acid). It is preferable to react 0.8 to 1.1 equivalents of the compound having one unsaturated double bond and one carboxyl group in one molecule with 1 equivalent of epoxy group of the above copolymer. In order to accelerate the reaction, 0.1 to 1% of a basic compound such as triphenylphosphine, triphenylstibine, triethylamine, triethanolamine, tetramethylammonium chloride, benzyltriethylammonium chloride as a reaction catalyst is added to the reaction solution. Is preferred. During the reaction, it is preferable to add a polymerization inhibitor (eg, methoxyphenol, methylhydroquinone, hydroquinone, phenothiazine) in an amount of 0.05 to 0.5% in the reaction solution in order to prevent polymerization. The reaction temperature is usually 90 to 150 ° C., and the reaction time is preferably 5 to 40 hours.

In the present invention, the plasticizer (B) is used. It is preferable to add a low molecular weight compound as a plasticizer (B) to the composition of the present invention because the ionic conductivity of the solid polymer electrolyte obtained by curing is further improved. The amount of the plasticizer (B) added is 900 to 1 with respect to 100 parts by weight of the component (A).
9900 parts by weight is preferable, 1600 to 19900 parts by weight is more preferable, and 2800 to 19900 parts by weight is particularly preferable. The larger the amount added, the higher the ionic conductivity of the solid polymer electrolyte, but if it is too large, the mechanical strength of the solid polymer electrolyte decreases.

The plasticizer (B) that can be used is (A)
Good compatibility with the components, high dielectric constant and boiling point of 70
A compound having a wide range of electrochemical stability, which is at least ℃, is suitable. Examples of the plasticizer (B) include oligoethers such as triethylene glycol methyl ether and tetraethylene glycol dimethyl ether, and carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, vinylene carbonate, and (meth) acryloyl carbonate. And aromatic nitriles such as benzonitrile and tolunitrile, dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, sulfolane, and phosphoric acid esters. Of these, oligoethers and carbonates are preferable, and carbonates are particularly preferable.

In the present invention, the electrolyte (C) is used. The proportion of the electrolyte in the composition of the present invention is preferably in the range of 0.1 to 50% by weight, particularly preferably 1 to 30% by weight. If the amount of the electrolyte is too large, the movement of the ions is significantly hindered. On the contrary, if the amount is too small, the absolute amount of the ions becomes insufficient and the ionic conductivity becomes small.

As the electrolyte (C) used in the present invention,
There is no particular limitation, and an electrolyte containing ions that are desired to be used as carriers by electric charge may be used. However, it is desirable that the solid dissociation constant in the solid polymer electrolyte obtained by curing is large. ₃ ) ₄ such as 4 NBF ₆
Quaternary ammonium salts, quaternary phosphonium salts such as (CH ₃ ) ₄ PBF ₆ , transition metal salts such as AgClO ₄ or hydrochloric acid,
Protic acids such as perchloric acid and borofluoric acid are recommended, and for example, alkali metal salts, quaternary ammonium salts, quaternary phosphonium salts or transition metal salts are preferable.

Examples of the alkali metal salt include LiCF
₃ SO ₃ , LiPF ₆ , LiClO ₄ , LiI, LiB
F ₄ , LiSCN, LiAsF ₆ , NaCF ₃ SO ₃ , Na
PF ₆ , NaClO ₄ , NaI, NaBF ₄ , NaAs
F ₆ , KCF ₃ SO ₃ , KPF ₆ , KI and the like can be mentioned.

In the present invention, a photopolymerization initiator (D) can be used. As the photopolymerization initiator (D), all known photopolymerization initiators can be used, but in particular, a wavelength of 350 to
Those having a maximum molar absorption coefficient of 50 or more between 450 nm can be preferably used. By using this photopolymerization initiator (D), the resin composition of the present invention becomes an ultraviolet curable resin composition. When the photopolymerization initiator (D) is used, its amount is preferably 0.5 to 70 parts by weight, and 0.1 to 3 parts by weight, based on 100 parts by weight of the component (A).
0 parts by weight is especially preferred.

Examples of the photopolymerization initiator (D) include radical polymerization initiators such as 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1.
(Ciba Specialty Chemicals, Irgacure 369), 2,4-diethylthioxanthone, 2-
Isopropyl thioxanthone, Michler's ketone, 4,
4'-bis (diethylamino) benzophenone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and the like can be mentioned. To be

These photopolymerization initiators (D) are other photopolymerization initiators, for example, 1-hydroxy-2-cyclohexylphenyl ketone, 2-hydroxy-2-methylpropiophenone, methylphenylglyoxylate, 2 , 2-
It can also be used in combination with diethoxyacetophenone.

In the present invention, a thermal polymerization initiator (E) can be used. As the thermal polymerization initiator (E), all known thermal polymerization initiators can be used, but those having a 10-hour half-life temperature of 10 ° C. or higher can be preferably used. By using this thermal polymerization initiator (E), the resin composition of the present invention becomes a thermosetting resin composition. When the thermal polymerization initiator (E) is used, its amount is preferably 0.5 to 70 parts by weight, and particularly preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the component (A).

Specific examples of the thermal polymerization initiator (E) include ketone peroxides such as methylcyclohexanone peroxide and cyclohexanone peroxide, and hydrous compounds such as diisopropylbenzene hydroperoxide, cumene hydroperoxide and t-butyl hydroperoxide. Peroxide, o-cyclobenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide,
Diacyl peroxides such as benzoyl peroxide and p-cyclobenzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di- (t-
Dialkyl peroxides such as butylperoxy) hexyne-3 and tris- (t-butylperoxy) triazine, 1,1-di-t-butylperoxy-3,3,5
-Trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, and 2,2-bis (4,4)
-Peroxyketals such as di-t-butylperoxycyclohexyl) propane, α-cumylperoxy neodecanoate, alkyl peresters such as t-butylperoxynonadecanoate and t-butylperoxypivalate, 2,2,4-Trimethylpentylperoxy-
2-ethylhexanoate, t-amyl peroxy-2
-Ethyl hexanoate, t-butyl peroxy-2-
Alkyl peresters such as ethylhexanoate, t-butylperoxyacetate, t-butylperoxybenzoate and di-t-butylperoxytrimethyl adipate, di-3-methoxyperoxydicarbonate, di-2-ethylhexylper Organic peroxides such as oxydicarbonate, bis (4-tbutylcyclohexyl) peroxydicarbonate and percarbonate such as diethylene glycol-bis (t-butylperoxycarbonate), 1,1′-azobis (cyclohexane-1- Carbonitrile), 2,2'-azobis (2-methyl-butyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis {2-methyl-N-
[1,1 Bis (hydroxymethyl) -2-hydroxyethyl] propion-amide}, 2,2′-azobis [2
-Methyl-N- (2-hydroxyethyl) propion-
Amido], 2,2'azobis (2-methyl-propionamide) dihydrate, azodi-t-octane and 2-
Examples thereof include azo compounds such as cyano-2-propylazoformamide, and these may be used alone or in combination of two or more kinds.

In the present invention, the reactive monomer (F) may be used. Examples of the reactive monomer (F) include carbitol (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, penta. Examples thereof include erythritol tetra (meth) acrylate and trimethylolpropane polyoxyethyl tri (meth) acrylate. The amount of the reactive monomer used is the copolymer (A) 10 having an aliphatic chain in the side chain and a specific functional group.
1 to 200 parts by weight is preferable with respect to 0 parts by weight.

The resin composition for a solid polymer electrolyte of the present invention has a cyano group and a specific functional group in its side chain (A), a plasticizer (B), an electrolyte (C), a photopolymerization initiator (D). as well as/
Alternatively, it can be obtained by mixing with a thermal polymerization initiator (E), and optionally by adding the reactive monomer (F), another polymer (G) and / or a solvent, and uniformly mixing them. it can. When a solvent is used, any solvent may be used as long as it does not inhibit the polymerization, for example, tetrahydrofuran, toluene and the like can be used.

In the present invention, the polymer (G) that can be used in some cases is, for example, polyethylene glycol, polyacrylonitrile, polybutadiene, poly (meth) acrylic acid esters, polystyrene, polyphosphazenes, polysiloxane or polysilane. . The amount of the polymer (G) used is preferably 0 to 100 parts by weight based on 100 parts by weight of the copolymer (A) component having an aliphatic chain in the side chain and a specific functional group.

The polymer solid electrolyte of the present invention comprises a cured product of the above resin composition for polymer solid electrolyte. This cured product is irradiated with electromagnetic waves (energy rays) such as ultraviolet rays to the resin composition for polymer solid electrolyte (for example, 1 to 100000 mJ / cm ^{2 in} the case of ultraviolet rays) to polymerize, or 20 to 200 ° C. It can be obtained by heating and polymerizing. In particular, a sheet polymer may be obtained by polymerizing the above resin composition for polymer solid electrolyte into a sheet (membrane, film) shape or the like, and then irradiating or heating with an electromagnetic wave such as an electron beam or an ultraviolet ray to heat the resin composition. Preferably, the degree of freedom in processing is expanded, which is a great advantage in application. In the case of producing a sheet-shaped solid polymer electrolyte, usually, a roll coater, a dip coater, a coater such as a curtain coater, etc., the above-mentioned solid polymer electrolyte resin composition is applied on a support, and then ultraviolet rays or the like. The resin composition may be cured by irradiation with electromagnetic waves or heating. Examples of the support include an aluminum vapor-deposited PET film and the like. In order to more reliably cure the surface, another support may be subsequently laminated on the surface of the cured film of the resin composition, and further irradiated with electromagnetic waves such as ultraviolet rays or heated.
Examples of the other support include a polypropylene film and the like. The obtained cured product is usually used after removing the support.

The polymer battery of the present invention has, for example, a structure in which the above-mentioned solid polymer electrolyte is sandwiched between a negative electrode and a positive electrode. This polymer battery is preferably in sheet form, and therefore, it is preferable to use sheet form for all of the solid polymer electrolyte, the negative electrode and the positive electrode. For the negative electrode, for example, a negative electrode active material processed into a sheet shape can be used. At the time of this processing, a collector such as a foil of aluminum, copper, nickel or the like or a binder for the negative electrode active material can be used. Binder resins can be used. As the negative electrode active material, it is preferable to use a substance having a low redox potential with an alkali metal ion as a carrier and a mixture thereof, since a battery having a high voltage and a high capacity can be obtained. For example, an alkali metal or a lithium / aluminum alloy. And alkali metal alloys such as lithium / lead alloys and lithium / antimony alloys, and carbon materials. The carbon material is L
When i ions are occluded, it is particularly preferable in that it has a low redox potential and is stable and safe. Examples of carbon materials capable of occluding and releasing Li ions include natural graphite, artificial graphite, vapor-phase process graphite, petroleum coke, Examples include coal coke, pitch-based carbon, polyacene, and fullerenes such as C ₆₀ and C ₇₀ .

As the above-mentioned positive electrode, for example, a positive electrode active material processed into a sheet shape can be used. At the time of this processing, a collector such as a foil of aluminum, copper, nickel or the like and a binding of the positive electrode active material are used. A binder resin as an agent can be used. As the positive electrode active material, when a material having a high redox potential such as a metal oxide, a metal sulfide, a conductive polymer or a carbon material or a mixture thereof is used, a high voltage,
It is preferable because a high capacity battery can be obtained. In particular, cobalt oxide, manganese oxide, vanadium oxide, nickel oxide,
It is preferable to use a metal oxide such as molybdenum oxide, or a metal sulfide such as molybdenum sulfide, titanium sulfide, or vanadium sulfide because the packing density is high, so that the volume capacity density is high, while manganese oxide, nickel oxide, cobalt oxide, or the like is used. Is preferable in terms of high capacity and high voltage. Further, it is preferable to use these positive electrode active materials in a state where Li element is inserted (composite) into a metal oxide or a metal sulfide in the form of, for example, LiCoO ₂ or LiMnO ₂ . L like this
The positive electrode can be prepared by a method of inserting an i element or a method of mixing a salt such as Li ₂ CO ₃ and a metal oxide and heating the mixture as described in US Pat. No. 4,357,215.

Further, in that it is flexible and easy to form a thin film,
It is preferable to use a conductive polymer as the positive electrode active material. Examples of the conductive polymer include polyaniline, polyacetylene and its derivatives, polypyrrole and its derivatives, polythienylene and its derivatives, polypyridinediyl and its derivatives, polyisothianaphthenylene and its derivatives, polyfurylene and its derivatives, polyselenophene. And derivatives thereof, polyparaphenylene vinylene, polythienylene vinylene, polyfurylene vinylene, polynaphthenylene vinylene, polyselenophene vinylene, polypyridine diyl vinylene, and other polyarylene vinylene, and derivatives thereof. Among them, a polymer of an aniline derivative soluble in an organic solvent is particularly preferable.

The conductive polymer used as an electrode active material in these batteries or electrodes is manufactured by a chemical or electrochemical method or any other known method.

[0032]

The present invention will be described in more detail below by showing typical examples. Note that these are merely examples for description, and the present invention is not limited to these.

Synthesis Example 1 (Synthesis Example of Curable Polymer (A)) 105 parts of cyanoethyl acrylate, 45 parts of glycidyl methacrylate, 150 parts of propylene carbonate and 4 parts of benzoyl peroxide were placed in a round bottom flask equipped with a stirrer and a cooling tube. 0.5 part was added and under a nitrogen stream, 75
The reaction was carried out at 5 ° C. for 5 hours to obtain a polymer liquid having a solid content of 50% and a weight average molecular weight of 20,000 (GPC method). 300 parts of this polymer solution, 22.0 parts of acrylic acid, 0.16 part of methylhydroquinone, 0.9 part of triphenylphosphine,
Propylene carbonate (22.0 parts) was added, mixed and dissolved, and reacted at 95 ° C for 32 hours to give an acrylic equivalent of 563,
Solid content 50%, weight average molecular weight 23000 (GPC method)
A polymer solution was obtained.

Synthesis Example 2 (Synthesis Example of Curable Polymer (A)) 65 parts of cyanoethyl acrylate and 40 parts of methyl acrylate were placed in a round bottom flask equipped with a stirrer and a cooling tube.
Parts, 45 parts of glycidyl methacrylate, 150 parts of propylene carbonate, and 4.5 parts of benzoyl peroxide were added, and the reaction was carried out at 75 ° C. for 5 hours under a nitrogen stream to obtain a solid content of 50% and a weight average molecular weight of 20000 (GPC method). A liquid for coalescence was obtained. 300 parts of this polymer liquid, 22.0 parts of acrylic acid, 0.16 parts of methylhydroquinone, 0.9 parts of triphenylphosphine, 22. parts of propylene carbonate.
0 parts was added, mixed and dissolved, and reacted at 95 ° C. for 32 hours,
Acrylic equivalent 563, solid content 50%, weight average molecular weight 2
A polymer solution of 3000 (GPC method) was obtained.

Synthesis Example 3 (Synthesis Example of Curable Polymer (A)) 60 parts of cyanoethyl acrylate and 60 butyl acrylate were placed in a round bottom flask equipped with a stirrer and a cooling tube.
Parts, 30 parts of glycidyl methacrylate, 150 parts of propylene carbonate and 4.5 parts of benzoyl peroxide were added, and the reaction was carried out at 75 ° C. for 5 hours under a nitrogen stream to obtain a solid content of 50% and a weight average molecular weight of 20,000 (GPC method). A liquid for coalescence was obtained. 300 parts of this polymer liquid, acrylic acid 15.0 parts, methylhydroquinone 0.16 parts, triphenylphosphine 0.9 parts, propylene carbonate 1
5.0 parts was added, mixed and dissolved, and reacted at 95 ° C. for 32 hours to obtain a polymer liquid having an acrylic equivalent of 792, a solid content of 50% and a weight average molecular weight of 23000 (GPC method).

Example 1 1.0 g of the polymer solution obtained in Synthesis Example 1 as a curable polymer (A), 4.5 g of ethylene carbonate and 4.5 g of diethyl carbonate as a plasticizer (B), and an electrolyte (C). LiPF ₆ 1.0 g and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photo radical polymerization initiator) 0.05 g as a photopolymerization initiator (D) were mixed well in an argon atmosphere to form an electrolyte. A mixed solution was obtained. This mixed liquid was applied on aluminum of an aluminum vapor-deposited PET film (30 μm) under an argon atmosphere to a thickness of 30 μm using a coater, and then irradiated with 200 mJ / cm ^{2 of} a high pressure mercury lamp to form a solid polymer electrolyte. After that, a polypropylene film (30 μm) was laminated on the solid polymer electrolyte layer, further irradiated with a 300 mJ / cm ² high-pressure mercury lamp, and then peeled off from the upper and lower layers to obtain a transparent self-supporting film of about 30 μm. A molecular solid electrolyte was obtained. The ionic conductivity of this film at 25 ° C. and −20 ° C. was measured and found to be 3.0 ms / cm (25 ° C.) and 0.3 s / cm.
(-20 ° C). In addition, this film at room temperature 2
When left for 4 hours, no leakage of plasticizer and electrolyte was observed.

Example 2 0.8 g of the polymer solution obtained in Synthesis Example 2 as (A),
(B) 4.6 g of ethylene carbonate and 4.6 g of diethyl carbonate, (C) LiPF ₆ 1.
0 g and 0.03 g of benzoyl peroxide as a thermal polymerization initiator (E) were well mixed in an argon atmosphere to obtain an electrolyte mixed solution. This mixed solution was applied on aluminum of aluminum vapor-deposited PET film (30 μm) to a thickness of 30 μm under an argon atmosphere using a coater, and then a polypropylene film having a thickness of 30 μm was laminated and heated at 80 ° C. for 5 hours,
After forming the polymer solid electrolyte, the polymer solid electrolyte was obtained as a transparent self-supporting film of about 30 μm by peeling from the upper and lower films. 25 of this film
When the ionic conductivity at 0 ° C and -20 ° C was measured, 3.
2ms / cm (25 ° C), 0.3s / cm (-20
℃). When this film was left at room temperature for 24 hours, no leakage of plasticizer and electrolyte was observed.

Example 3 0.6 g of the polymer solution obtained in Synthesis Example 3 as (A),
(B) 4.7 g of ethylene carbonate and 4.7 g of diethyl carbonate, (C) LiPF ₆ 1.
0 g, 0.05 g of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photoradical polymerization initiator) as (D) were well mixed in an argon atmosphere to obtain an electrolyte mixed solution. This mixed liquid was applied on aluminum of an aluminum vapor-deposited PET film (30 μm) under an argon atmosphere to a thickness of 30 μm using a coater, and then irradiated with 200 mJ / cm ^{2 of} a high pressure mercury lamp to form a solid polymer electrolyte. After that, a polypropylene film (30 μm) was laminated on the solid polymer electrolyte layer, further irradiated with a 300 mJ / cm ² high-pressure mercury lamp, and then peeled off from the upper and lower layers to obtain a transparent self-supporting film of about 30 μm. A molecular solid electrolyte was obtained. The ionic conductivity of this film at 25 ° C. and −20 ° C. was measured to be 3.2 ms / cm (25 ° C.), 0.3 s / cm.
(-20 ° C). In addition, this film at room temperature 2
When left for 4 hours, no leakage of plasticizer and electrolyte was observed.

Example 4 (A) 1.8 g of the polymer solution obtained in Synthesis Example 3,
4.1 g of ethylene carbonate and 4.1 g of diethyl carbonate as (B), and LiPF ₆ 1. as of (C).
0 g, 0.05 g of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photoradical polymerization initiator) as (D) were well mixed in an argon atmosphere to obtain an electrolyte mixed solution. This mixed liquid was applied on aluminum of an aluminum vapor-deposited PET film (30 μm) under an argon atmosphere to a thickness of 30 μm using a coater, and then irradiated with 200 mJ / cm _{2 of} a high pressure mercury lamp to form a solid polymer electrolyte. After that, a polypropylene film (30 μm) was laminated on the solid polymer electrolyte layer, further irradiated with a high pressure mercury lamp of 300 mJ / cm ₂ and then peeled from the upper and lower layers to obtain a transparent self-supporting film of about 30 μm. A polymer solid electrolyte was obtained. The ionic conductivity of this film at 25 ° C. and −20 ° C. was measured to be 3.2 ms / cm (25 ° C.), 0.3 s / cm.
(-20 ° C). In addition, this film at room temperature 2
When left for 4 hours, no leakage of plasticizer and electrolyte was observed.

Example 5 0.8 g of the polymer solution obtained in Synthesis Example 2 as (A),
(B) 4.6 g of ethylene carbonate and diet
4.6 g of carbonate, LiClO as (C) _Four  
1.0 g, benzoylpero as a thermal polymerization initiator (E)
Mix 0.03 g of cyside well in an argon atmosphere,
An electrolyte mixture was obtained. This mixed solution under an argon atmosphere,
Coated on the aluminum of aluminum vapor deposition PET film (30 μm)
Using a coater to a thickness of 30 μm,
Laminate polypropylene film and heat at 80 ℃ for 5 hours
After forming a solid polymer electrolyte, fill the upper and lower layers.
By peeling from the frame, a transparent self-supporting film of about 30 μm
A polymer solid electrolyte was obtained as a film. Of this film
When the ionic conductivity at 25 ° C and -20 ° C was measured,
3.2 ms / cm (25 ° C), 0.3 s / cm (-2
It was 0 degreeC). Also, this film at room temperature for 24 hours
No liquid leakage of plasticizer and electrolyte was observed when left to stand.
won.

Example 6 0.8 g of the polymer solution obtained in Synthesis Example 2 as (A),
As (B), 4.6 g of ethylene carbonate and 4.6 g of diethyl carbonate, and as (C), LiBF ₄ 1.
0 g and 0.03 g of benzoyl peroxide as a thermal polymerization initiator (E) were well mixed in an argon atmosphere to obtain an electrolyte mixed solution. This mixed solution was applied on aluminum of aluminum vapor-deposited PET film (30 μm) to a thickness of 30 μm under an argon atmosphere using a coater, and then a polypropylene film having a thickness of 30 μm was laminated and heated at 80 ° C. for 5 hours,
After forming the polymer solid electrolyte, the polymer solid electrolyte was obtained as a transparent self-supporting film of about 30 μm by peeling from the upper and lower films. 25 of this film
When the ionic conductivity at 0 ° C and -20 ° C was measured, 3.
2ms / cm (25 ° C), 0.3s / cm (-20
℃). When this film was left at room temperature for 24 hours, no leakage of plasticizer and electrolyte was observed.

Comparative Example 1 Dipentaerythritol caprolactone modified (ε-caprolactone 12 mol modified) instead of the curable resin (A).
Hexaacrylate (6 functional, acrylic equivalent = 325:
Kayalad DPCA-120 (manufactured by Nippon Kayaku Co., Ltd.))
1.0 g, (B) ethylene carbonate 4.5 g
And 4.5 g of diethyl carbonate, Li as (C)
1.0 g of PF _{6 and} 0.05 g of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photoradical polymerization initiator) as (D) were mixed well in an argon atmosphere to obtain an electrolyte mixture. It was This mixed solution was subjected to an argon atmosphere under an aluminum vapor-deposited PET film (30 μm).
m) coated on aluminum with a coater to a thickness of 30 μm, and then irradiated with 200 mJ / cm ^{2 of} high pressure mercury lamp to form a polymer solid electrolyte, and then a polypropylene film is formed on the polymer solid electrolyte layer. (30 μm)
Is further laminated, and after further irradiating with a 300 mJ / cm ² high pressure mercury lamp, it is peeled off from the upper and lower films to give about 30
A solid polymer electrolyte was obtained as a transparent self-supporting film of μm. When the ionic conductivity of this film was measured at 25 ° C. and −20 ° C., it was 2.5 ms / cm (25 ° C.), 0.
It was 2 ms / cm (-20 ° C). Further, when this film was left at room temperature for 24 hours, leakage of plasticizer and electrolyte was observed.

Comparative Example 2 0.6 g of ethylene oxide-modified trimethylolpropane triacrylate (trifunctional, acrylic equivalent = 142: Kayarad THE-330 (manufactured by Nippon Kayaku Co., Ltd.)) in place of the curable resin (A), ( B) 4.7 g of ethylene carbonate and 4.7 g of diethyl carbonate,
1.0 g of LiPF ₆ as (C) and 0.03 g of benzoyl peroxide (thermal polymerization initiator) as (E) were well mixed in an argon atmosphere to obtain an electrolyte mixed solution. This mixed solution was coated on an aluminum vapor-deposited PET film (30 μm) having a thickness of 30 using an coater under an argon atmosphere.
After coating to a thickness of μm, it was heated at 80 ° C. for 5 hours to obtain a polymer solid electrolyte as a transparent self-supporting film of about 30 μm. The ionic conductivity of this film at 25 ° C. and −20 ° C. was measured and found to be 3.0 ms / cm (25 ° C.), 0.2 ms /
It was cm (-20 degreeC). Further, when this film was left at room temperature for 24 hours, leakage of plasticizer and electrolyte was observed.

Comparative Example 3 0.3 g of ethylene oxide-modified trimethylolpropane triacrylate (trifunctional, acrylic equivalent = 142) in place of the curable resin (A), 4.85 g of ethylene carbonate and (4) diethylene carbonate as (B).
85 g, LiPF ₆ 1.0 g as (C), benzoyl peroxide (thermal polymerization initiator) 0.03 as (E)
g was thoroughly mixed in an argon atmosphere to obtain an electrolyte mixed solution. This mixed solution was applied onto an aluminum vapor-deposited film (30 μm) having a thickness of 30 using an coater under an argon atmosphere.
After coating to a thickness of .mu.m, it was heated at 80.degree. C. for 5 hours, but it was not cured and a polymer solid electrolyte could not be obtained as a self-standing film.

From the above results, in the case of a monomer having a large functional group equivalent of 325 even if it has 6 functional groups as in Comparative Example 1, or in the case of a small functional group equivalent as in Comparative Examples 2 and 3, the number of functional groups is small. In the case of a monomer as small as 3, the resin does not cure at a resin concentration of 5%, the resin concentration required for curing increases, and the ion conductivity at low temperature also decreases. On the other hand, in the case of a solid polymer electrolyte obtained by curing a resin composition using the curable polymer of the present invention, it has a strength capable of peeling from a support at a resin concentration of 9.0% or less, and a thin film It is clear that it has good strength and high ionic conductivity, especially ionic conductivity at low temperature, which is due to the low resin concentration in the solid electrolyte. Further, since the solid polymer electrolyte obtained by curing the resin composition of the present invention has a cyano group, it has no liquid leakage and has good liquid retention.

[0046]

The resin composition for a polymer solid electrolyte of the present invention comprises a curable polymer (A) having a specific structure of 0.5% by weight or more and less than 9.0% by weight and a plasticizer (B). It is composed of an electrolyte (C), is excellent in thin film processability, and easily obtains a thin film having good film strength. The polymer solid electrolyte obtained by curing this resin composition also has good film strength, It also has the feature of high ionic conductivity.

Claims (12)

[Claims] 1. A side chain having a cyano group and an ethylenically unsaturated double bond, wherein the ethylenically unsaturated double bond equivalent is 850.
A resin composition for a solid polymer electrolyte, comprising the following curable polymer (A), a plasticizer (B) and an electrolyte (C). 2. The resin composition for a polymer solid electrolyte according to claim 1, which contains 0.5% by weight to 9.0% by weight of the curable polymer (A). 3. The resin composition for a polymer solid electrolyte according to claim 1, which contains 0.5% by weight to 5.0% by weight of the curable polymer (A). 4. The resin composition for a polymer solid electrolyte according to claim 1, which contains 0.5% by weight to 3.0% by weight of the curable polymer (A). 5. The resin composition for a solid polymer electrolyte according to claim 1, which contains a photopolymerization initiator (D). 6. A photopolymerization initiator (D) having a wavelength of 350 to 45.
The resin composition for a polymer solid electrolyte according to claim 5, which has a maximum molar absorption coefficient at 0 nm of 50 or more. 7. The resin composition for a polymer solid electrolyte according to claim 1, which contains a thermal polymerization initiator (E). 8. The resin composition for polymer solid electrolyte according to claim 7, wherein the 10-hour half-life temperature of the thermal polymerization initiator (E) is 10 ° C. or higher. 9. The electrolyte according to claim 1, wherein the electrolyte (C) is at least one selected from alkali metal salts, quaternary ammonium salts, quaternary phosphonium salts and transition metal salts. A resin composition for a molecular solid electrolyte. 10. A solid polymer electrolyte comprising a cured product of the resin composition for a solid polymer electrolyte according to claim 1. 11. The solid polymer electrolyte according to claim 10, which is in the form of a sheet. 12. A polymer battery comprising the polymer solid electrolyte according to claim 9 or 11.