Curable composition for electrolyte gel, electrolyte gel, storage battery and electronic device

Abstract

To provide a curable composition for electrolyte gel that can be cured at room temperature and uses therefor.SOLUTION: A curable composition for electrolyte gel disclosed herein comprises component (A): a vinyl polymer with a crosslinkable functional group and an ether bond, component (B): an oxidizer, component (C): a reductant, and component (D): an electrolyte. In the component (A), the polymerization ratio of monomers with ether bonds is more than 30 mol%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a curable composition for an electrolyte gel, an electrolyte gel, a storage battery, and an electronic device. [Background technology]

[0002] Batteries, such as lithium-ion batteries, are increasingly being used as energy storage devices in many applications, in particular due to their high energy density or specific energy and low self-discharge. For example, lithium-ion batteries are already used as batteries in automobiles (particularly as energy storage devices in electric vehicles), as storage devices in IoT devices such as laptops and smartphones, and as storage devices in stationary storage devices for domestic and industrial use.

[0003] Lithium-ion batteries contain an electrolyte that is placed in or between two distinct electrodes, an anode and a cathode, where electrochemical energy is stored in the battery by conversion of chemical energy into electrical energy.

[0004] For example, Patent Document 1 discloses a liquid composition capable of forming a gel electrolyte membrane, which contains a radical polymerizable composition consisting of an ethylenically unsaturated compound having an oxyethylene group and a polymerization inhibitor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2021-134251 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned conventional techniques have room for improvement in terms of curability at room temperature.

[0007] An object of one aspect of the present invention is to provide a curable composition for electrolyte gel that can be cured at room temperature and to realize use of the same. [Means for solving the problem]

[0008] In order to solve the above problems, a curable composition for an electrolyte gel according to one embodiment of the present invention includes: component (A): a vinyl polymer having a crosslinkable functional group and an ether bond; component (B): an oxidizing agent; component (C): a reducing agent; and component (D): an electrolytic substance, wherein the polymerization ratio of a monomer having an ether bond in component (A) is more than 30 mol %. Effect of the Invention

[0009] According to one aspect of the present invention, it is possible to provide a curable composition for an electrolyte gel that can be cured at room temperature, and use of the same. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an example of an embodiment of the present invention will be described in detail, but the present invention is not limited thereto. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more, B or less". In addition, all documents described in this specification are incorporated by reference in this specification.

[0011] 1. Curable composition for electrolyte gel The curable composition for electrolyte gel according to one embodiment of the present invention includes (A) component: a vinyl polymer having a crosslinkable functional group and an ether bond, (B) component: an oxidizing agent, (C) component: a reducing agent, and (D) component: an electrolytic substance, and the polymerization ratio of the monomer having an ether bond in the (A) component is more than 30 mol%. In this specification, the curable composition for electrolyte gel means a curable composition for obtaining an electrolyte gel. Hereinafter, the curable composition for electrolyte gel is also simply referred to as a curable composition. The electrolyte gel can be obtained by curing the curable composition. In this specification, "curing" means "gelling".

[0012] Usually, a vinyl polymer having a crosslinkable functional group will cure at room temperature in the presence of component (B). However, even in the presence of component (B), if component (D) is also present, the curable composition will not cure at room temperature. In contrast, it has been found that the composition can be cured at room temperature by using component (C) in addition to components (B) and (D), and further using a vinyl polymer having a crosslinkable functional group and having a polymerization ratio of a monomer having an ether bond of more than 30 mol% as component (A). It is speculated that component (A) crosslinks while holding component (D) by the ether structure, so that the inhibition of curing at room temperature by component (D) can be suppressed. This is also suggested by the fact that the volume resistivity of the cured product is low, as shown in the examples described later. The ethylenically unsaturated compound having an oxyethylene group described in Patent Document 1 is a compound having a main chain containing an oxyethylene group, and is different from the vinyl polymer which is component (A) in this specification. Therefore, it is speculated that the liquid composition described in Patent Document 1 is difficult to cure at room temperature. It has also been discovered that, in one embodiment of the present invention, the use of component (A) makes it possible to obtain a cured product with low rubber hardness and a soft material.

[0013] [Component (A): Vinyl polymer having crosslinkable functional group and ether bond] The curable composition contains a vinyl polymer having a crosslinkable functional group and an ether bond as component (A). As the vinyl monomer constituting the main chain of the vinyl polymer, various types of monomers can be used.

[0014] However, in one embodiment of the present invention, the polymerization ratio of the monomer having an ether bond in the vinyl polymer is more than 30 mol%. From the viewpoint of curability, the polymerization ratio of the monomer having an ether bond is preferably 50 mol% or more, more preferably 70 mol% or more, and even more preferably 90 mol% or more. The upper limit of the polymerization ratio of the monomer having an ether bond may be, for example, 100 mol%.

[0015] It can also be said that the vinyl monomer constituting the main chain of the vinyl polymer includes at least a vinyl monomer having an ether bond. Examples of the vinyl monomer having an ether bond include (meth)acrylic acid ester monomers having an ether bond. It can also be said that the (meth)acrylic acid ester monomers having an ether bond have an ester bond and an ether bond. Examples of the (meth)acrylic acid ester monomers having an ether bond include 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypropylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, ethyl carbitol (meth)acrylate, and 2-phenoxyethyl (meth)acrylate.

[0016] From the viewpoint of curability, the vinyl polymer preferably contains the ether bond in the side chain. It can also be said that the vinyl polymer preferably has a side chain containing an ether bond. In addition, the side chain containing the ether bond is preferably at least one selected from the group consisting of a methoxypolyethylene glycol group, a methoxypropylene glycol group, a methoxytriethylene glycol group, a methoxyethyl group, an ethylcarbitol group, and a phenoxyethyl group.

[0017] Other usable vinyl monomers include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Nonyl acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, stearyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl (meth)acrylate, γ-(methacryloyloxypropyl)trimethoxysilane, ethylene oxide adduct of (meth)acrylic acid, trifluoromethylmethyl (meth)acrylate, (meth)acrylic 2-Trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecyl (meth)acrylate (Meth)acrylic acid ester monomers such as vinylethyl; styrene-based monomers such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and its salts; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, vinylidene fluoride; silicon-containing vinyl monomers such as vinyltrimethoxysilane, vinyltriethoxysilane; maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid; fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid;Examples of the monomers include maleimide monomers such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; alkenes such as ethylene and propylene; conjugated dienes such as butadiene and isoprene; vinyl chloride, vinylidene chloride, allyl chloride, and allyl alcohol.

[0018] These may be used alone or in combination. The (meth)acrylic acid herein refers to acrylic acid and / or methacrylic acid.

[0019] The main chain of the vinyl polymer is preferably a (meth)acrylic polymer, since the product has excellent physical properties such as flexibility, viscosity, and elongation at low temperatures. That is, the main chain of the vinyl polymer is preferably produced by polymerizing mainly (meth)acrylic acid ester monomers, and more preferably produced by polymerizing mainly acrylic acid ester monomers. Here, "mainly" means that of the monomer units constituting the vinyl polymer, 50 mol % or more are (meth)acrylic acid ester monomers, and preferably 70 mol % or more are (meth)acrylic acid ester monomers.

[0020] Particularly preferred acrylic acid ester monomers include acrylic acid alkyl ester monomers, specifically ethyl acrylate, 2-methoxyethyl acrylate, stearyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, and 2-methoxybutyl acrylate. These preferred monomers may be copolymerized or block copolymerized with other monomers.

[0021] The molecular weight distribution of the vinyl polymer, i.e., the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography (GPC), is not particularly limited, but is preferably less than 1.8, more preferably 1.7 or less, even more preferably 1.6 or less, even more preferably 1.5 or less, particularly preferably 1.4 or less, and most preferably 1.3 or less. If the molecular weight distribution is too large, the viscosity at the same molecular weight between crosslinking points increases, and handling tends to become difficult. In this specification, the GPC measurement is performed using chloroform as the mobile phase and a polystyrene gel column, and the number average molecular weight and the like can be calculated in terms of polystyrene.

[0022] The number average molecular weight of the vinyl polymer is not particularly limited, but is preferably in the range of 500 to 1,000,000, more preferably 1,000 to 100,000, and even more preferably 5,000 to 50,000, as measured by GPC. If the molecular weight is too low, the viscosity is low and handling is easy, but the resulting cured product tends to have insufficient elongation and / or poor flexibility. On the other hand, if the molecular weight is too high, handling tends to be difficult.

[0023] From the viewpoint of flexibility of the obtained cured product, the lower limit of the content of the (A) component in 100% by weight of the curable composition is preferably 50% by weight or more, more preferably 55% by weight or more. The upper limit of the content of the (A) component in 100% by weight of the curable composition is less than 100% by weight, and from the viewpoint of ion conductivity, it is preferably 80% by weight or less.

[0024] <Method of synthesizing vinyl polymers> The vinyl polymer can be obtained by various polymerization methods. The polymerization method is not particularly limited, but the radical polymerization method is preferred from the viewpoints of versatility of monomers, ease of control, etc., and among radical polymerization methods, the controlled radical polymerization method is more preferred. The controlled radical polymerization method can be classified into a "chain transfer agent method" and a "living radical polymerization method". The living radical polymerization method is more preferred because it is easy to control the molecular weight and molecular weight distribution of the obtained vinyl polymer, and the atom transfer radical polymerization method is particularly preferred because of the availability of raw materials and the ease of introducing functional groups into the polymer terminals. For each of these polymerization methods, for example, the descriptions in JP-A-2005-232419 and JP-A-2006-291073 can be referred to.

[0025] <Crosslinkable functional group> The crosslinkable functional group of the vinyl polymer is not particularly limited, but is preferably at least one type selected from the group consisting of a radical crosslinkable functional group, an epoxy group, and a hydrolyzable silyl group, in terms of excellent properties of the cured product after crosslinking.

[0026] In cases where rubber-like properties are particularly required for the cured product obtained by curing the curable composition, it is preferable that at least one of the crosslinkable functional groups is located at the end of the molecular chain, since the molecular weight between crosslinking points, which has a large effect on rubber elasticity, can be large. More preferably, the vinyl polymer has all of the crosslinkable functional groups at the end of the molecular chain.

[0027] (Radical crosslinking functional group) The radical crosslinkable functional group is not particularly limited, and examples thereof include vinyl groups and (meth)acryloyl groups. When the crosslinkable functional group of the vinyl polymer is a radical crosslinkable functional group, the lower limit of the number of radical crosslinkable functional groups that the vinyl polymer has in the molecule is preferably 1.0 or more on average per molecule, more preferably 1.2 or more, and even more preferably 1.4 or more. The upper limit of the number of radical crosslinkable functional groups is preferably 2 or less on average per molecule. If the number of radical crosslinkable functional groups is within the above range, the vinyl polymers are sufficiently crosslinked with each other by the catalyst and the initiator, and a cured product with sufficient strength is obtained.

[0028] In one embodiment, the (meth)acryloyl group has a structure represented by the following general formula (1). -OC(O)C(R 5 )=CH2(1) In general formula (1), R 5 R is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. The hydrocarbon group may be optionally substituted with one or more heteroatoms selected from the group consisting of oxygen atoms, nitrogen atoms, sulfur atoms, fluorine atoms, chlorine atoms, bromine atoms and iodine atoms. 5 Specific examples of the alkyl group include H, CH3, CH2CH3, (CH2) n Examples of the aryl group include CH3 (n is an integer from 2 to 19), C6H5, CH2OH, and CN. From the viewpoint of the reactivity of the component (A), R 5 is preferably H or CH3.

[0029] As a method for introducing a (meth)acryloyl group into a polymer, for example, the method described in paragraphs

[0081] to

[0090] of Japanese Patent No. 5,536,383 can be mentioned.

[0030] (epoxy group) In one embodiment, the epoxy group is not particularly limited, but examples thereof include glycidyl group, glycidyl ether group, 3,4-epoxycyclohexyl group, oxetane group, aminoglycidyl group, and phenoxyglycidyl group. When the crosslinkable functional group of component (A) is an epoxy group, the lower limit of the number of epoxy groups contained in the molecule of component (A) is preferably 1.0 or more on average per molecule, more preferably 1.4 or more, and even more preferably 2.0 or more. The upper limit of the number of epoxy groups is preferably 4.0 or less on average per molecule.

[0031] (Hydrolyzable silyl group) In one embodiment, the hydrolyzable silyl group includes a group represented by general formula (2). -[Si(R 1 ) 2-b (Y) b O] m -Si(R 2 ) 3-a (Y) a (2) In the formula, R 1 , R 2 each represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a triorganosiloxy group represented by (R')3SiO- (R' is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and the three R's may be the same or different), and R 1 or R 2 When two or more are present, they may be the same or different. Y represents a hydroxyl group or a hydrolyzable group, and when two or more Y are present, they may be the same or different. a represents 0, 1, 2, or 3, and b represents 0, 1, or 2. m is an integer of 0 to 19, provided that a+mb≧1 is satisfied.

[0032] Examples of hydrolyzable groups include commonly used groups such as hydrogen atom, alkoxy group, acyloxy group, ketoximate group, amino group, amide group, aminooxy group, mercapto group, and alkenyloxy group. Among these, alkoxy group, amide group, and aminooxy group are preferred, and alkoxy group is particularly preferred because it is mildly hydrolyzable and easy to handle. Among alkoxy groups, the smaller the number of carbon atoms, the higher the reactivity. In other words, the reactivity decreases in the order of methoxy group > ethoxy group > propoxy group, and these can be selected according to the purpose and application.

[0033] The hydrolyzable group or hydroxyl group can be bonded to one silicon atom in the range of 1 to 3, and (a+Σb) is preferably in the range of 1 to 5. When two or more hydrolyzable groups or hydroxyl groups are bonded to the hydrolyzable silyl group, they may be the same or different. The number of silicon atoms forming the hydrolyzable silyl group is one or more, but in the case of silicon atoms linked by siloxane bonds, etc., it is preferable that the number is 20 or less. In particular, the hydrolyzable silyl group represented by the general formula (3) is preferable in terms of easy availability. -Si(R 2 ) 3-a (Y) a (3) (In the formula, R 2 and Y is the same as above, and a is an integer of 1 to 3. Although there are no particular limitations, it is preferable that a is 2 or more in order to provide good curability and good physical properties of the cured product.

[0034] As the vinyl polymer having such hydrolyzable silyl group, a polymer having a hydrolyzable silyl group, in which two hydrolyzable groups are bonded to one silicon atom, is often used. However, when used at low temperatures, particularly when a very fast curing speed is required, the curing speed is not sufficient, and when flexibility after curing is required, the crosslinking density must be reduced, and therefore, stickiness (surface tack) may occur due to insufficient crosslinking density. In such a case, it is preferable to use one in which a is 3 (for example, a trimethoxy functional group).

[0035] In addition, those where a is 3 (e.g., trimethoxy functional group) cure faster than those where a is 2 (e.g., dimethoxy functional group), but in terms of mechanical properties (elongation, etc.), those where a is 2 may be superior. In order to balance the cure and physical properties, those where a is 2 (e.g., dimethoxy functional group) and those where a is 3 (e.g., trimethoxy functional group) may be used together.

[0036] For example, when Y is the same, the more a, the higher the reactivity of Y, so by selecting Y and a, it is possible to control the curability and the mechanical properties of the cured product, and can be selected according to the purpose and use. In addition, when a is 1, it can be used as a chain extender by mixing with a polymer having a hydrolyzable silyl group, specifically at least one polymer selected from polysiloxane, polyoxypropylene, and polyisobutylene. It is possible to obtain a composition that has low viscosity before curing and high elongation at break, low bleeding, and low surface contamination after curing.

[0037] The number of hydrolyzable silyl groups in component (A) is not particularly limited, but from the viewpoint of the curability of the composition and the physical properties of the cured product, it is preferable for the molecule to have an average of at least 1, more preferably from 1.1 to 4.0, and even more preferably from 1.2 to 3.5.

[0038] A known method can be used to introduce a hydrolyzable silyl group into a vinyl polymer. For example, the method described in paragraphs

[0083] to

[0117] of JP-A-2007-302749 can be mentioned. Methods for producing vinyl polymers having a hydrolyzable silyl group at the molecular chain end, particularly (meth)acrylic polymers, are disclosed in JP-B-3-14068, JP-B-4-55444, JP-A-6-211922, etc.

[0039] (Other resins) The component (A) may be used alone or in combination with other resins.

[0040] [Component (B): Oxidizing agent] The curable composition contains an oxidizing agent as component (B). There is no particular limitation on component (B), and a common oxidizing agent can be used. In particular, from the viewpoint of curability, it is preferable that component (B) is an organic peroxide.

[0041] Specific examples of organic peroxides include hydroperoxides, dialkyl peroxides, peroxycarboxylic acids, peroxy esters, diacyl peroxides, peroxy carbonates, ketone peroxides, and peroxy ketals. From the viewpoint of curability, peroxy esters, peroxy carbonates, ketone peroxides, and peroxy ketals are preferred, and peroxy esters and peroxy carbonates are particularly preferred. For example, examples of peroxy esters include t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, and t-butylperoxybenzoate.

[0042] From the viewpoint of curability, the content of the (B) component in the curable composition is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight, and even more preferably 1 to 10 parts by weight, relative to 100 parts by weight of the (A) component.

[0043] [Component (C): Reducing agent] The curable composition includes a reducing agent as component (C). The component (C) is not particularly limited and may be a normal reducing agent. Specific examples of the reducing agent include sulfinic acid, organic amines, transition metal salts, and the like. Examples of the organic amine include azo compounds such as para-toluidine (p-methylaniline); azoisobutyric acid dinitrile; α-aminosulfones such as bis-(tolylsulfonemethyl)amine, bis-(tolylsulfonemethyl)ethylamine, and bis-(tolylsulfonemethyl)-benzylamine; tertiary amines such as diisopropyl-p-toluidine, dimethylaniline, and dimethyl-p-toluidine; amine-aldehyde condensation products, for example, condensation products of primary amines such as aniline or butylamine with aliphatic aldehydes such as butylaldehyde; and thiourea derivatives such as 2-mercaptobenzimidazole, methylthiourea, dibutylthiourea, tetramethylthiourea, and ethylenethiourea. Examples of transition metal salts include cobalt naphthenate, copper naphthenate, and vanadyl acetylacetonate. Among these, from the viewpoint of reactivity, organic amines and transition metal salts are preferred, and para-toluidine and vanadyl acetylacetonate are more preferred. In particular, from the viewpoint of the effect on curability and ion conductivity, it is preferred that component (C) is an organic amine.

[0044] From the viewpoint of the effect on curability and ion conductivity, the content of the (C) component in the curable composition is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, and even more preferably 0.1 to 5 parts by weight, relative to 100 parts by weight of the (A) component.

[0045] [(D) Component: Electrolyte] The curable composition includes an electrolyte as component (D). Component (D) is not particularly limited and may be a normal electrolyte. Component (D) may be an electron pair compound between a fluorine atom-containing anion and a lithium cation. There is no particular limitation on the electron pair compound between a fluorine atom-containing anion and a lithium cation, and specific examples thereof include lithium hexafluorophosphate, LiPF3(CF2CF3)3, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(perfluoroethanesulfonyl)imide, lithium (fluorosulfonyl)(nonafluorobutanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium trifluoromethanesulfonate, lithium tris(trifluoromethanesulfonyl)methide, lithium bis(oxalato)borate, and lithium difluoro(oxalato)borate. Among these, lithium hexafluorophosphate and lithium bis(trifluoromethanesulfonyl)imide are preferred in terms of stability and ionic conductivity. Other examples of the component (D) that can be used include 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, N-(2-methoxyethyl)-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide.

[0046] From the viewpoints of the viscosity and ionic conductivity of the curable composition, the content of the (D) component in the curable composition is preferably 1 to 100 parts by weight, more preferably 5 to 80 parts by weight, and even more preferably 10 to 70 parts by weight, relative to 100 parts by weight of the (A) component.

[0047] [Component (E): Solvent] The curable composition may further include a solvent as component (E). The component (E) is not particularly limited, and the curable composition may include, as component (E), at least one compound selected from the group consisting of cyclic carbonates, acyclic carbonates, aliphatic esters, alicyclic ethers, aliphatic bifunctional ethers, lactones, dinitriles, and compounds containing at least one carboxylate group and an ether group.

[0048] Examples of cyclic carbonates include ethylene carbonate, propylene carbonate, vinyl ethylene carbonate, and fluoroethylene carbonate.

[0049] Examples of acyclic carbonates include ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, 2,2,2-trifluoroethyl carbonate, and methyl 2,2,3,3-tetrafluoropropyl carbonate.

[0050] Examples of the aliphatic ester include methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate (EA), butyl acetate, etc. From the viewpoint of electrolyte solubility and ionic conductivity, propyl formate, ethyl acetate, or a mixture of these compounds is preferred.

[0051] Examples of the alicyclic ether include tetrahydrofuran, 2-methyltetrahydrofuran, and derivatives thereof.

[0052] Aliphatic difunctional ethers include dimethyl ether, methyl ethyl ether, diethyl ether, methoxypropyl ether, methoxyisopropyl ether, ethoxypropyl ether, methoxyisopropyl ether, dipropyl ether, diisopropyl ether, methoxy t-butyl ether, ethoxy t-butyl ether, and the like.

[0053] Examples of lactones include β-propionolactone, γ-butyrolactone, γ-hexalactone, γ-heptalactone, γ-octalactone, and δ-valerolactone.

[0054] Examples of dinitriles include adiponitrile, 3,5-dioxa-heptane dinitrile, 1,4-bis(cyanoethoxy)butane, bis(2-cyanoethyl)-monoformal, bis(2-cyanoethyl)-diformal, bis(2-cyanoethyl)-triformal, ethylene glycol bis(2-cyanoethyl)ether, bis(2-(2-cyanoethoxy)ethyl)ether, 4,7,10,13-tetraoxahexadecanedinitrile, 4,7,10,13,16-pentaoxanonadecane-1,14-dinitrile, 3,6,9,12,15,18-hexaoxaeicosane dinitrile, 4,10-dioxa-undecane dinitrile, 1,10-dicyano-3,8-dioxadecane, 4,10-dioxa-tridecane dinitrile, and 6,9-dioxa-tetradecane dinitrile.

[0055] Compounds containing at least one carboxylic acid ester group and an ether group include methoxy-ethyl acetate, ethoxy-ethyl acetate, and 2-(2-ethoxyethoxy)-ethyl acetate.

[0056] The following aliphatic ethers can also be used as component (E). Although there are no particular limitations on the aliphatic ethers, specific examples include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and dipropylene glycol monomethyl ether.

[0057] Other solvents that can be used as component (E) include dimethyl sulfoxide, 1,3-dioxolane, formamide, acetamide, dimethylformamide, acetonitrile, propionitrile, nitromethane, ethyl monoglyme, phosphate triesters, trimethoxymethane, dioxolane derivatives, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, anisole, N-methylpyrrolidone, fluorinated carboxylates, and the like.

[0058] [Component (F): radical reactive monomer] The curable composition may further contain a radically reactive monomer as component (F) from the viewpoints of viscosity adjustment, adjustment of the mechanical properties of the cured product, compatibility with electrolytes, etc. The component (F) is not particularly limited, but specific examples thereof include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, and tert-butyl (meth)acrylate. ) 2-ethylhexyl acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, stearyl (meth)acrylate, glyceryl (meth)acrylate (meth)acrylic acid ester monomers such as dimethylsilyl, 2-aminoethyl (meth)acrylate, phenoxyethyl (meth)acrylate, γ-(methacryloyloxypropyl)trimethoxysilane, ethylene oxide adducts of (meth)acrylic acid, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate; styrene monomers such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, and styrenesulfonic acid and its salts;Fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride; silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid; fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid; maleimide monomers such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; nitriles such as acrylonitrile and methacrylonitrile. amido group-containing vinyl monomers such as acrylamide, amino monomers, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, acrylmorpholine, methacrylamide, and other amide group-containing vinyl monomers, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, vinyl cinnamate, and other vinyl esters, ethylene, propylene, and other alkenes, butadiene, isoprene, and other conjugated dienes, vinyl chloride, vinylidene chloride, allyl chloride, allyl alcohol, (2-oxo-1,3-dioxolan-4-yl)methyl (meth)acrylate, vinyl ethylene carbonate, and polyethylene glycol monoacrylate. In terms of the viscosity of the curable composition, solubility in the electrolyte, and the like, 4-hydroxybutyl (meth)acrylate (i.e., 4-hydroxybutyl (meth)acrylate), acrylic morpholine, allyl alcohol, (2-oxo-1,3-dioxolan-4-yl)methyl (meth)acrylate, and vinyl ethylene carbonate are preferred.

[0059] From the viewpoints of the viscosity and curability of the curable composition, and the flexibility of the cured product, the content of the (F) component in the curable composition is preferably 1 to 100 parts by weight, more preferably 2 to 80 parts by weight, and even more preferably 3 to 70 parts by weight, relative to 100 parts by weight of the (A) component.

[0060] [Other ingredients] The curable composition may contain other components in addition to the components (A), (B), (C), (D), (E), and (F). The other components may be used alone or in combination of two or more. Examples of the other components are described below.

[0061] <Leveling agent> The curable composition may contain a leveling agent to adjust the surface unevenness when cured. Examples of the leveling agent include fluorine-based, silicone-based, acrylic-based, ether-based, and ester-based leveling agents.

[0062] <Antifoaming agent> The curable composition may contain an antifoaming agent to prevent the generation of bubbles. Preferred examples include acrylic, silicone, or fluorine-based antifoaming agents.

[0063] <Diluent> The curable composition may contain a diluent. Examples of the diluent include a non-reactive diluent and a reactive diluent. From the viewpoint of effectively suppressing the reaction between the components in the curable composition and the diluent, a non-reactive diluent is preferred.

[0064] The diluent is not particularly limited, and is preferably one that can be dried at 200° C. or less. Examples of such diluents include cellosolve acetate, propylene glycol monomethyl ether acetate, γ-butyrolactone, pyrrolidone, vinylpyrrolidone, N-methyl-2-pyrrolidone, dimethylformamide, and dimethylacetamide.

[0065] <Adhesion promoter> The curable composition may contain an adhesion promoter to improve adhesion to a substrate. As the adhesion promoter, a crosslinkable silyl group-containing compound or a vinyl monomer having a polar group is preferable, and a silane coupling agent or a vinyl monomer having an acidic group is more preferable.

[0066] As the silane coupling agent, for example, a silane coupling agent having both a functional group having atoms other than carbon and hydrogen atoms in the molecule and a crosslinkable silyl group can be used. Examples of the functional group having atoms other than carbon and hydrogen atoms include an epoxy group, an isocyanate group, an isocyanurate group, a carbamate group, an amino group, a mercapto group, a carboxyl group, a halogeno group, and a (meth)acrylic group.

[0067] <Filling agent> The curable composition may contain a filler to ensure a certain strength. The filler is not particularly limited, and silica other than fumed silica (e.g., crystalline silica, fused silica, hydrated silicic acid), dolomite, carbon black, titanium oxide, active zinc oxide, etc. are preferred from the viewpoint of improving the filling rate with a small amount. In particular, when it is desired to obtain a cured product with high strength using these fillers, it is preferable to mainly use at least one filler selected from crystalline silica, fused silica, hydrated silicic acid, carbon black, active zinc oxide, etc.

[0068] <Plasticizer> The curable composition may contain a plasticizer to adjust the viscosity, slump property, or mechanical properties such as hardness, tensile strength, or elongation when cured. Examples of the plasticizer include phthalate compounds such as dibutyl phthalate, diisononyl phthalate (DINP), diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate (DIDP), and butyl benzyl phthalate; terephthalate compounds such as bis(2-ethylhexyl)-1,4-benzenedicarboxylate (e.g., EASTMAN168 (manufactured by EASTMAN CHEMICAL)); 1,2-cyclohexanedicarboxylic acid diisononyl ester (e.g., Hexamol non-phthalate ester compounds such as dioctyl adipate, dioctyl sebacate, dibutyl sebacate, diisodecyl succinate, and tributyl acetyl citrate; unsaturated fatty acid ester compounds such as butyl oleate and methyl acetylricinoleate; alkylsulfonic acid phenyl esters (Mesamoll (LANXESS)); phosphate ester compounds such as tricresyl phosphate and tributyl phosphate; trimellitic acid ester compounds; chlorinated paraffins; hydrocarbon oils such as alkyl diphenyls and partially hydrogenated terphenyls; process oils; epoxidized soybean oil, and epoxy plasticizers such as epoxy benzyl stearate.

[0069] [Method of producing curable composition] The method for producing the curable composition is not particularly limited, but may be, for example, a method of kneading each component as follows. First, the component (D) is mixed with the component (E) and stirred to obtain a uniform electrolyte solution, and then the vinyl polymer component (A) is added and further mixed and stirred. Next, the component (B) is added and mixed and stirred, and finally the component (C) is added and mixed and stirred. Alternatively, the mixing order of the components (B) and (C) may be reversed. Then, the component (F) and other components may be added.

[0070] The apparatus used for kneading includes a stirring and defoaming apparatus such as a triple roll mill, a planetary mixer, etc. The above-mentioned apparatuses may be used alone or in combination of two or more kinds.

[0071] In addition, when kneading, in order to prevent the stability of the curable composition from being impaired due to heat generation during kneading, the temperature during kneading is preferably 0°C or higher and 70°C or lower, more preferably 5°C or higher and 60°C or lower, and even more preferably 10°C or higher and 50°C or lower.

[0072] 2. Electrolyte Gel The electrolyte gel according to one embodiment of the present invention is obtained by curing the above-mentioned curable composition. That is, the electrolyte gel contains the above-mentioned components (A) to (D), and may optionally contain a component (E), a component (F) and / or other components. The electrolyte gel may also be called a gel electrolyte, a polymer electrolyte, or an electrolyte layer gel.

[0073] The curable composition can be cured by leaving it at room temperature, but may also be cured by light irradiation or contact with moisture. For curing by light irradiation, light rays and electron beams can be used. Examples of sources of light rays and / or electron beams include high pressure mercury lamps, low pressure mercury lamps, electron beam irradiation devices, halogen lamps, light emitting diodes, semiconductor lasers, and metal halides. The relative humidity during curing by contact with moisture is preferably 5 to 95%, more preferably 10 to 80%.

[0074] [3. Storage Batteries and Electronic Devices] An embodiment of the present invention also includes a storage battery comprising the above-mentioned electrolyte gel. The storage battery may comprise an electrolyte gel between the positive electrode and the negative electrode. The storage battery may or may not comprise a separator between the positive electrode and the negative electrode in addition to the electrolyte gel. Examples of such storage batteries include lithium ion storage batteries, nickel metal hydride batteries, and NAS batteries.

[0075] An embodiment of the present invention also includes an electronic device comprising the above-mentioned electrolyte gel. Such electronic devices include a light control panel, a dye-sensitized solar cell, a sensor, an actuator, and a photoelectron device.

[0076] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0077] An embodiment of the present invention may include the following features. <1> A curable composition for an electrolyte gel, comprising: component (A): a vinyl polymer having a crosslinkable functional group and an ether bond; component (B): an oxidizing agent; component (C): a reducing agent; and component (D): an electrolytic substance, wherein the polymerization ratio of a monomer having an ether bond in component (A) exceeds 30 mol %. <2> The component (A) contains the ether bond in a side chain. <1> The curable composition for electrolyte gel according to claim 1. <3> the side chain containing an ether bond is at least one selected from the group consisting of a methoxypolyethylene glycol group, a methoxypropylene glycol group, a methoxytriethylene glycol group, a methoxyethyl group, an ethylcarbitol group, and a phenoxyethyl group; <2> The curable composition for electrolyte gel according to claim 1. <4> The crosslinkable functional group of the component (A) is at least one selected from the group consisting of a radical crosslinkable functional group, an epoxy group, and a hydrolyzable silyl group. <1> ~ <3> 13. The curable composition for an electrolyte gel according to claim 12, <5> The main chain of the component (A) is a (meth)acrylic polymer. <1> ~ <4> 13. The curable composition for an electrolyte gel according to claim 12, <6> The component (B) is an organic peroxide. <1> ~ <5> 13. The curable composition for an electrolyte gel according to claim 12, <7> The component (C) is an organic amine. <1> ~ <6> 13. The curable composition for an electrolyte gel according to claim 12, <8> The component (D) is an electron pair compound of a fluorine atom-containing anion and a lithium cation. <1> ~ <7> 13. The curable composition for an electrolyte gel according to claim 12, <9> (E) component: further containing a solvent; <1> ~ <8> 13. The curable composition for an electrolyte gel according to claim 12, <10> The component (E) contains at least one compound selected from the group consisting of cyclic carbonates, acyclic carbonates, aliphatic esters, alicyclic ethers, aliphatic bifunctional ethers, lactones, dinitriles, and compounds containing at least one carboxylic acid ester group and an ether group; <9> The curable composition for electrolyte gel according to claim 1. <11> (F) component: further containing a radical reactive monomer; <1> ~ <10> 13. The curable composition for an electrolyte gel according to claim 12, <12> <1> ~ <11> 2. An electrolyte gel obtained by curing the curable composition for an electrolyte gel according to claim 1. <13> <12> A storage battery comprising the electrolyte gel according to claim 1. <14> <12> An electronic device comprising the electrolyte gel according to claim 1. EXAMPLES

[0078] The present invention will be described in more detail below with reference to examples, but is not limited to these examples. In the following, unless otherwise specified, "%" refers to "% by mass."

[0079] [Evaluation method] [Curing at room temperature] The curable composition obtained in the examples or comparative examples was poured into a mold measuring 150 mm x 100 mm x 2 mm thick, leveled and degassed, and then allowed to stand at room temperature for 16 hours to evaluate whether it cured or not.

[0080] [Resistance of hardened product] A sheet-like cured product was obtained by the method described in [Curability at room temperature]. A test piece (Φ100 × thickness 12 mm size) was obtained from the sheet-like cured product. The surface resistivity and volume resistivity of the test piece were measured at 23°C and 55R.H.% using an R8340 ULTRA HIGH RESISTANCE METER (manufactured by Advantest) in accordance with JIS K6911.

[0081] [Flexibility of the cured product] The rubber hardness of the cured product was measured under a load of 1 kg according to the hardness test specified in JIS K 7312.

[0082] [Electrolyte gel for lithium-ion batteries] [Materials used in the Examples and Comparative Examples] Ingredient (A) · P(MEA) (Radical curing telechelic polyacrylate obtained by introducing a radical crosslinking functional group into the main chain of homopolymerized 2-methoxyethyl acrylate, number average molecular weight = 6,000, molecular weight distribution = 1.1, has methoxyethyl groups as side chains) MM200C (polyacrylate obtained by introducing a radical crosslinking functional group to one end of the main chain of a copolymer of 2-methoxyethyl acrylate / acrylonitrile in a molar ratio of 94 / 6, manufactured by Kaneka Corporation, molecular weight 3,000, molecular weight distribution = 1.1, has a methoxyethyl group as a side chain) ●(B) Component Perbutyl O (t-butylperoxy-2-ethylhexanoate (purity 97%), manufactured by NOF Corporation) ●(C) component Paratoluidine ●(D) Component Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) ●(E) Component Ethylene carbonate (EC) / propylene carbonate (PC) (weight ratio 1 / 1) mixed solvent ●(F) Ingredients 4-Hydroxybutyl acrylate Resin components other than component (A) RC-110C (radical-curable telechelic polyacrylate obtained by introducing radical crosslinking functional groups into the main chain of n-butyl acrylate homopolymerized, manufactured by Kaneka Corporation, number average molecular weight 16,000, molecular weight distribution 1.1, does not have ether bonds) RC-200C (radical-curable telechelic polyacrylate obtained by introducing radical crosslinking functional groups into the main chain of n-butyl acrylate / ethyl acrylate / 2-methoxyethyl acrylate copolymerized in a molar ratio of 24.97 / 46.00 / 29.03, manufactured by Kaneka Corporation, number average molecular weight 24,000, molecular weight distribution 1.1) [Examples 1 to 4] In a container, the component (D) was mixed with the component (E) in the amounts shown in Table 1, and stirred and dissolved with a spoon. A container dedicated to blending (φ89×φ98×94 mm, capacity 470 cc, made of polypropylene) was used as the container. Then, the components (A) and (B) were added to the container and mixed, and stirred with a spoon. Furthermore, the components in this container were charged together with the component (C) into a stirring and degassing device dedicated to mixing (Awatori Rentaro ARV-310, manufactured by Thinky Corporation). The charged components were stirred and mixed by applying shear, and then degassed and stirred. Furthermore, the component (F) was charged into this stirring and degassing device, degassed and stirred, and a curable composition for electrolyte gel was obtained. In Example 4, the component (E) was not used.

[0083] [Comparative Examples 1 and 2] A curable composition for electrolyte gel was obtained in the same manner as in Example 1, except that a resin component other than component (A) shown in Table 1 was used instead of component (A).

[0084] [Evaluation Results] The compositions and evaluation results of the examples and comparative examples are shown in Table 1 below.

[0085] [Table 1]

[0086] (Room temperature curing evaluation) In Comparative Examples 1 and 2, the composition did not harden at room temperature even after the addition of component (C). In contrast, in Examples 1 to 4, which used component (A) in which the polymerization ratio of a monomer having an ether bond (2-methoxyethyl acrylate) was more than 30 mol %, the composition exhibited good hardening properties at room temperature.

[0087] (resistance value of cured product) Examples 1 to 4 containing the component (A) showed lower or similar specific volume resistivities than Comparative Examples 1 and 2 in which a resin component other than the component (A) was blended.

[0088] (rubber hardness) Throughout the examples and comparative examples, a low rubber hardness was exhibited, and a soft electrolyte gel (cured product) was obtained.

[0089] (Overall review) As shown in Comparative Examples 1 and 2, a curable composition containing components (B), (C), and (D) but not component (A) does not cure at room temperature after mixing. In contrast, it was found that a curable composition containing components (A), (B), (C), and (D) exhibits excellent curability at room temperature and achieves low resistance for the resulting cured product. [Industrial Applicability]

[0090] One embodiment of the present invention can be used in, for example, a storage battery, an electronic device, and the like.

Claims

1. The composition comprises: (A) component: a vinyl polymer having a crosslinkable functional group and an ether bond; (B) component: an oxidizing agent; (C) component: a reducing agent; and (D) component: an electrolytic substance; A curable composition for an electrolyte gel, wherein the polymerization ratio of a monomer having an ether bond in the component (A) is more than 30 mol %.

2. The curable composition for an electrolyte gel according to claim 1 , wherein the component (A) contains the ether bond in a side chain.

3. The curable composition for electrolyte gel according to claim 2, wherein the side chain containing an ether bond is at least one selected from the group consisting of a methoxypolyethylene glycol group, a methoxypropylene glycol group, a methoxytriethylene glycol group, a methoxyethyl group, an ethylcarbitol group, and a phenoxyethyl group.

4. 2. The curable composition for an electrolyte gel according to claim 1, wherein the crosslinkable functional group of the component (A) is at least one selected from the group consisting of a radical crosslinkable functional group, an epoxy group, and a hydrolyzable silyl group.

5. The curable composition for an electrolyte gel according to claim 1 , wherein the main chain of the component (A) is a (meth)acrylic polymer.

6. The curable composition for electrolyte gel according to claim 1 , wherein the component (B) is an organic peroxide.

7. The curable composition for electrolyte gel according to claim 1 , wherein the component (C) is an organic amine.

8. 2. The curable composition for an electrolyte gel according to claim 1, wherein the component (D) is an electron pair compound of a fluorine atom-containing anion and a lithium cation.

9. The curable composition for electrolyte gel according to claim 1 , further comprising a component (E): a solvent.

10. The curable composition for an electrolyte gel according to claim 9, comprising, as the component (E), at least one compound selected from the group consisting of cyclic carbonates, acyclic carbonates, aliphatic esters, alicyclic ethers, aliphatic bifunctional ethers, lactones, dinitriles, and compounds containing at least one carboxylic acid ester group and an ether group.

11. Component (F): The curable composition for electrolyte gel according to claim 1, further comprising a radical-reactive monomer.

12. An electrolyte gel obtained by curing the curable composition for an electrolyte gel according to any one of claims 1 to 11.

13. A storage battery comprising the electrolyte gel according to claim 12.

14. An electronic device comprising the electrolyte gel of claim 12.