Solid electrolyte, method for manufacturing solid electrolyte, battery, and article

Abstract

A solid electrolyte that is obtained by curing a composition including a monofunctional urethane (meth)acrylate and an electrolytic salt, wherein the monofunctional urethane (meth)acrylate is one or more types of monomer selected from the reaction products of compounds including a prescribed (meth)acryloyloxy group.

Description

[Technical Field]

[0001] The present disclosure relates to solid electrolytes, methods for making solid electrolytes, batteries comprising the solid electrolytes, and articles comprising the batteries. [Background technology]

[0002] Conventional nickel-metal hydride batteries and lithium-ion secondary batteries use liquid electrolytes, which must be sealed and packed in a metal can or the like to prevent leakage, making it difficult to reduce the weight and thickness of the batteries. In recent years, polymer electrolyte batteries have attracted attention as highly safe batteries that are free from concerns about leakage and combustion of the electrolyte. Polymer electrolyte batteries are known for their lightweight, thin, and highly designable shapes. For example, Patent Document 1 discloses a polymer electrolyte battery containing an ion conductor obtained by copolymerizing an ion-conducting compound, a crystallization-inhibiting compound, and an orienting ion-conducting compound, and dispersing an electrolyte salt in the polymer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-175838 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the development of flexible devices such as wearable devices has progressed. Components such as batteries included in flexible devices are required to have higher bending properties and recovery than conventional ones, and durability against repeated bending (hereinafter also referred to as "repeated bending durability"). Furthermore, because flexible devices can be carried around and used in a variety of environments, batteries included in flexible devices are required to have flexibility that allows them to exhibit repeated bending durability even at low temperatures (0°C).

[0005] However, conventional polymer electrolyte batteries have not been found to be sufficient in terms of durability against repeated bending, ionic conductivity at low temperatures, and flexibility.

[0006] The present invention is devised to solve these problems, and aims to provide a solid electrolyte that has excellent ionic conductivity and flexibility at low temperatures and excellent durability against repeated bending, a method for producing the solid electrolyte, a battery including the solid electrolyte, and an article including the battery. [Means for solving the problem]

[0007] The present invention is based on the discovery that a solid electrolyte obtained by curing a composition containing a specific urethane (meth)acrylate having a polyether chain and a urethane bond, and an electrolyte salt, has excellent ionic conductivity and flexibility at low temperatures, and also has excellent durability against repeated bending.

[0008] The present invention provides the following means. [1] A solid electrolyte obtained by curing a composition containing a monofunctional urethane (meth)acrylate and an electrolyte salt, wherein the monofunctional urethane (meth)acrylate is one or more monomers selected from the reaction products of the following (i), (ii), and (iii): (i) A reaction product of an equimolar reaction between a monool having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. (ii) A reaction product of an equimolar reaction of a monool having a polyether skeleton, a diisocyanate, and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one group reactive with an isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. (iii) A reaction product of an equimolar reaction of a polyol having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. [2] The solid electrolyte according to the above [1], wherein the monool having a polyether skeleton is at least one selected from polyether monools and polyether carbonate monools. [3] The solid electrolyte according to the above [1] or [2], wherein the monofunctional urethane (meth)acrylate is a reaction product of the above (i). [4] The solid electrolyte according to the above [1], wherein the polyol having a polyether skeleton is at least one selected from polyether polyols and polyether carbonate polyols. [5] The solid electrolyte according to any one of the above [1] to [4], wherein the monool having a polyether skeleton and the polyol having a polyether skeleton each have an oxyalkylene group. [6] The solid electrolyte according to the above [5], wherein the proportion of oxyethylene groups relative to the total amount of oxyalkylene groups in the monool having a polyether skeleton or the polyol having a polyether skeleton is 5 to 95 mass%. [7] The solid electrolyte according to the above [5] or [6], wherein the proportion of oxypropylene groups relative to the total amount of oxyalkylene groups in the monool having a polyether skeleton or the polyol having a polyether skeleton is 5 to 95 mass%. [8] The solid electrolyte according to any one of the above [1] to [7], wherein the glass transition temperature of the homopolymer of the monofunctional urethane (meth)acrylate is −55° C. or lower. [9] The solid electrolyte according to any one of the above [1] to [8], wherein the molecular weight of the monofunctional urethane (meth)acrylate is 2,500 to 30,000.

[10] The solid electrolyte according to any one of the above [1] to [9], wherein the content of the electrolyte salt is 0.01 to 50 mass % based on the solid electrolyte.

[11] The electrolyte salt is LiBF4, LiPF6, LiClO4, LiN(CF3SO2)2, MgN(CF3SO2)2, NaPF 6、 The solid electrolyte according to any one of the above [1] to

[10] , which is at least one selected from the group consisting of NaN(CF3SO2)2 and NaN(FSO2)2.

[12] A battery comprising the solid electrolyte according to any one of [1] to

[11] above.

[13] An article comprising the battery described in

[12] above.

[14] A composition comprising a monofunctional urethane (meth)acrylate and an electrolyte salt, wherein the monofunctional urethane (meth)acrylate is one or more monomers selected from the reaction products of the following (i), (ii), and (iii): (i) A reaction product of an equimolar reaction between a monool having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. (ii) A reaction product of an equimolar reaction of a monool having a polyether skeleton, a diisocyanate, and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one group reactive with an isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. (iii) A reaction product of an equimolar reaction of a polyol having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule.

[15] A method for producing a solid electrolyte, comprising irradiating the composition according to

[14] above with light having a wavelength of 300 to 410 nm to cure it. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a solid electrolyte that is excellent in ionic conductivity and flexibility at low temperatures and in durability to repeated bending, a method for producing the solid electrolyte, a battery including the solid electrolyte, and an article including the battery. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below. In this specification, what is considered to be preferable can be adopted arbitrarily, and it can be said that a combination of preferable things is more preferable. In addition, in this specification, the expression "XX to YY" means "XX or more and YY or less." Furthermore, in this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower and upper limits described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60." Furthermore, in the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. In addition, in this specification, the term "(meth)acryloyloxy group" is a general term for an acryloyloxy group and a methacryloyloxy group. In this specification, the term "(meth)acrylate" is a general term for acrylate and methacrylate. Furthermore, in this specification, unless otherwise specified, the term "number of functional groups" refers to the number of (meth)acryloyloxy groups in one molecule. The term "average number of functional groups" refers to the average number of (meth)acryloyloxy groups in one molecule, where the formula weight or number average molecular weight based on the chemical formula is one unit. Furthermore, in this specification, the term "monofunctional urethane (meth)acrylate" refers to a urethane (meth)acrylate in which the average number of functional groups per molecule is substantially 1, and a urethane (meth)acrylate in which the average number of functional groups per molecule is 0.7 to 1.4, preferably 0.8 to 1.3, is considered to be a urethane (meth)acrylate having substantially one (meth)acryloyloxy group per molecule, i.e., a monofunctional urethane (meth)acrylate. In addition, in this specification, the term "equimolar reaction product" means that the molar ratio of reacting compounds is substantially 1, and a reaction product in which the molar ratio is 0.7 to 1.4, preferably 0.8 to 1.3, is considered to be an equimolar reaction product. Similarly, "the molar ratio of the reactive groups (or compounds) is equal" means that the molar ratio of the reactive groups (or compounds) is substantially 1, and when the molar ratio is 0.7 to 1.4, preferably 0.8 to 1.3, the molar ratio of the reactive groups (or compounds) is considered to be equal. In this specification, the "hydroxyl value" is determined by measurement in accordance with JIS K 1557: 2007. The "hydroxyl value-based molecular weight" is a value calculated from the formula 56100 / (hydroxyl value)×(number of active hydrogen atoms in the initiator). In addition, in this specification, the "NCO index" in the reaction of an isocyanate group-containing compound with a hydroxyl group-containing compound is a value obtained by multiplying by 100 the equivalent ratio of the isocyanate groups of the isocyanate group-containing compound to the hydroxyl groups of the hydroxyl group-containing compound. In this specification, unless otherwise specified, the term "molecular weight" refers to the formula weight based on a chemical formula, or, in the case of a compound having a molecular weight distribution, the number average molecular weight. The "number average molecular weight" is the polystyrene-equivalent molecular weight determined by gel permeation chromatography (GPC) based on a calibration curve prepared using standard polystyrene samples. In this specification, a "polyether carbonate monool" refers to a monool having both a polyether skeleton and a polycarbonate skeleton, and a "polyether carbonate polyol" refers to a polyol having both a polyether skeleton and a polycarbonate skeleton.

[0011] [Solid electrolyte] The solid electrolyte of the present invention is a solid electrolyte obtained by curing a composition containing a monofunctional urethane (meth)acrylate and an electrolyte salt, and the monofunctional urethane (meth)acrylate is one or more monomers selected from the reaction products of the following (i), (ii), and (iii): (i) A reaction product of an equimolar reaction between a monool having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. (ii) A reaction product of an equimolar reaction of a monool having a polyether skeleton, a diisocyanate, and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one group reactive with an isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. (iii) A reaction product of an equimolar reaction of a polyol having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule.

[0012] [Monofunctional urethane (meth)acrylate] A solid electrolyte containing a monofunctional urethane (meth)acrylate can be photopolymerized or thermally polymerized by the (meth)acryloyloxy group of the monofunctional urethane (meth)acrylate. Furthermore, since the monofunctional urethane (meth)acrylate has a polyether chain as a flexible graft chain that does not contribute to crosslinking, a cured product with excellent flexibility can be obtained. Furthermore, the cured product exhibits little temperature dependence of the storage modulus over a wide temperature range from -20 to 80°C, and can maintain excellent flexibility even at low temperatures below 0°C. The (meth)acryloyloxy group of the monofunctional urethane (meth)acrylate is preferably an acryloyloxy group from the viewpoint of curing speed.

[0013] The monofunctional urethane (meth)acrylate is one or more monomers (hereinafter also referred to as "first monomer") selected from the reaction products of the above (i) to (iii) (hereinafter also referred to as "monomer 1-1," "monomer 1-2," and "monomer 1-3"). Of these, the monofunctional urethane (meth)acrylate is preferably the reaction product of the above (i), from the viewpoint of further exerting the effects of the present invention. The first monomer may be used alone or in combination of two or more kinds.

[0014] The molecular weight of the first monomer is preferably 2,500 or more, more preferably 4,000 or more, and even more preferably 5,000 or more. The molecular weight of the first monomer is preferably 30,000 or less, more preferably 20,000 or less, and even more preferably 17,000 or less. The molecular weight of the first monomer is preferably 2,500 to 30,000, more preferably 4,000 to 20,000, and even more preferably 5,000 to 17,000. When the molecular weight is 2,500 or more, the solid electrolyte tends to be flexible and better ion conductivity is easily obtained, and when the molecular weight is 30,000 or less, the toughness of the cured film is excellent. When two or more types of first monomers are used in combination, it is preferable that the molecular weight of each be within the above range.

[0015] <Monomer 1-1> Monomer 1-1 is a reaction product of (i), which is an equimolar reaction product of a monool (i-1) having a polyether skeleton and a compound (i-2) having a (meth)acryloyloxy group, and the compound (i-2) having a (meth)acryloyloxy group is a compound having one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule.

[0016] Monomer 1-1 is preferably at least one selected from the group consisting of compounds represented by formula (1-1) and compounds represented by formula (1-2). From the viewpoint of achieving a higher ion transference number and better ionic conductivity, compounds represented by formula (1-2) are more preferred.

[0017] [ka]

[0018] [ka]

[0019] In formula (1-1) and formula (1-2), R 1 is a monovalent organic group having one or two (meth)acryloyloxy groups. R 12 is preferably an alkylene group having 2 to 8 carbon atoms, and more preferably an alkylene group having 2 to 4 carbon atoms. 12 may be the same or different. Two or more types of R 12 If present, -OR 12 - The chain can be block or random. 12 is preferably at least one selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group and a 1-ethylethylene group, and more preferably at least one selected from an ethylene group and a propylene group.

[0020] Also, (OR 12 ) is also preferably a unit based on a monomer a having one epoxy group and an ether bond other than the ether bond of the epoxy group in one molecule. The unit based on the monomer a is preferably a unit represented by formula (11). One type of monomer a may be used, or two or more types may be used in combination.

[0021] [ka]

[0022] In formula (11), R 101 -R 103 -OR 104 is a monovalent group represented by R 102 is a hydrogen atom or -R 105 -OR 106 R is a monovalent group represented by 103 , R 105 are each independently a linear or branched alkylene group having 1 to 3 carbon atoms, and R 104 , R 106 are each independently a linear or branched alkyl group having 1 to 18 carbon atoms. R 103 , R 105 The alkylene groups are each independently preferably a methylene group, an ethylene group, an n-propylene group, or an isopropylene group, more preferably a methylene group or an ethylene group, and even more preferably a methylene group. R 104 , R 106 The number of carbon atoms of each of the groups independently is preferably 1 to 14, more preferably 1 to 12, and further preferably 2 to 10. R 104 , R 106 Examples of the linear alkyl group include methyl, ethyl, n-propyl, n-butyl, n-octyl, n-decyl, lauryl, cetyl, and stearyl, with methyl, ethyl, and n-butyl being preferred. The branched alkyl group has a structure in which the hydrogen atoms in the linear alkyl group (excluding the hydrogen atoms bonded to the terminal carbon) are substituted with alkyl groups. Examples of the substituting alkyl groups include methyl and ethyl groups. The branched alkyl group is preferably a 2-ethylhexyl group.

[0023] The monomer a is preferably a monomer represented by formula (12).

[0024] [ka]

[0025] R in equation (12) 101 and R102 is R in Equation (11). 101 and R 102 is the same as

[0026] Examples of the monomer represented by formula (12) include methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether, and hexyl glycidyl ether. Of these, butyl glycidyl ether and 2-ethylhexyl glycidyl ether are preferred because they result in a solid electrolyte with better flexibility.

[0027] In formula (1-1) and formula (1-2), R 13 is an alkyl group having 1 to 20 carbon atoms. 13 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a methyl group, an ethyl group or a butyl group, and even more preferably a butyl group. a is an integer of 20 to 600. a is preferably an integer of 35 to 500, and more preferably an integer of 65 to 250.

[0028] In formula (1-2), R 14 is a chain hydrocarbon group having 2 to 20 carbon atoms or a cyclic hydrocarbon group having a ring structure having 6 to 20 carbon atoms. 14 may be the same or different, and these groups may have one or more substituents.

[0029] R 14 The number of carbon atoms in the chain hydrocarbon group is not particularly limited as long as it is 2 to 20, but is preferably 2 to 18, more preferably 2 to 16, and even more preferably 2 to 8. 14 The chain hydrocarbon group is preferably a linear or branched alkylene group, and is preferably unsubstituted.

[0030] R 14 When is a chain hydrocarbon group having a substituent, the substituent is not particularly limited, and examples thereof include an alkyl group having 1 to 8 carbon atoms; a halogen atom such as a chlorine atom; and an alkoxy group such as a methoxy group or an ethoxy group. The alkyl group having 1 to 8 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, etc. Among these, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a t-butyl group are preferred, and a methyl group, an ethyl group, and a t-butyl group are more preferred. R 14 When is a chain hydrocarbon group having a substituent, the number of the substituents is not particularly limited, but is preferably 1 to 4, and more preferably 1 to 2.

[0031] R in formula (1-2) 14 When the ring is a cyclic hydrocarbon group having a ring structure with 6 to 20 carbon atoms, the atoms constituting the ring may contain oxygen atoms, but if an oxygen atom is contained, the adjacent atoms are not both oxygen atoms.

[0032] R 14 When is a cyclic hydrocarbon group having a substituent, the substituent is not particularly limited, and examples thereof include an alkyl group having 1 to 8 carbon atoms; a halogen atom such as a chlorine atom; and an alkoxy group such as a methoxy group or an ethoxy group. The alkyl group having 1 to 8 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, etc. Among these, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a t-butyl group are preferred, and a methyl group, an ethyl group, and a t-butyl group are more preferred. R 14 When is a cyclic hydrocarbon group having a substituent, the number of the substituents is not particularly limited, but is preferably 1 to 4, and more preferably 1 to 2.

[0033] (R 14 -OC(=O)-O) b is R 14 Two or more different (R 14-OC(=O)-O) units, and three or more types of (R 14 It may contain a unit represented by —O—C(═O)—O). Two or more (R 14 The arrangement of units represented by -OC(=O)-O) may be random, may be block, or may be a combination of both random and block.

[0034] b is preferably an integer of 2 to 50, and more preferably an integer of 3 to 30.

[0035] (Monool (i-1) having a polyether skeleton) When the monomer 1-1 is a compound represented by formula (1-1), the monool (i-1) having a polyether skeleton is a compound obtained by ring-opening polymerization of an initiator having an active hydrogen-containing group and having one or more active hydrogen atoms with an alkylene oxide and / or the monomer a, and has an initiator residue, a polyether chain, and hydroxyl groups corresponding to the number of active hydrogen atoms in the initiator. When the monomer 1-1 is a compound represented by formula (1-2), the monool (i-1) having a polyether skeleton is a compound obtained by ring-opening polymerization of an initiator having an active hydrogen-containing group and having one or more active hydrogen atoms with carbon dioxide and excess alkylene oxide and / or the monomer a, and has an initiator residue, a polyether chain, a polycarbonate chain, and hydroxyl groups corresponding to the number of active hydrogen atoms in the initiator.

[0036] The mass ratio of the monomer a to the total mass of the alkylene oxide and the monomer a is preferably 0 to 90 mass%, more preferably 0 to 85 mass%, and even more preferably 10 to 80 mass%, from the viewpoint of adjusting flexibility and strength.

[0037] The alkylene oxide is preferably an alkylene oxide having 2 to 8 carbon atoms, and more preferably an alkylene oxide having 2 to 4 carbon atoms. Specific examples of the alkylene oxide include propylene oxide, ethylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide.

[0038] Examples of the active hydrogen-containing group contained in the initiator include a hydroxyl group, a carboxyl group, and an amino group having one hydrogen atom bonded to a nitrogen atom. The active hydrogen-containing group contained in the initiator is preferably a hydroxyl group or a carboxyl group, more preferably a hydroxyl group, and even more preferably an alcoholic hydroxyl group.

[0039] Examples of initiators having one active hydrogen include monohydric alcohols, monohydric phenols, monocarboxylic acids, and amine compounds having one hydrogen atom bonded to a nitrogen atom.Preferably, the initiator is a monohydric aliphatic alcohol or a monohydric aliphatic carboxylic acid, and more preferably a monohydric aliphatic alcohol.In addition, a polyoxyalkylene monool having a lower molecular weight than the monool having the target polyether skeleton may be used as the initiator.

[0040] The number of carbon atoms in the monohydric aliphatic alcohol as the initiator is preferably 1 to 20, more preferably 2 to 8. Specific examples of the monohydric aliphatic alcohol as the initiator include ethanol, propanol, 2-propanol, and butanol. The monovalent aliphatic carboxylic acid as the initiator preferably has 2 to 20 carbon atoms, and more preferably 2 to 8 carbon atoms, including the carbon atoms of the carboxy group.

[0041] The oxyalkylene group in the monool (i-1) having a polyether skeleton is preferably a combination of an oxypropylene group and another group, from the viewpoint that the solid electrolyte is likely to become flexible and that better ionic conductivity is likely to be obtained. The oxyalkylene group other than the oxypropylene group is preferably an oxyethylene group, and more preferably has an oxypropylene group and an oxyethylene group.

[0042] The ratio of oxypropylene groups to the total amount of oxyalkylene groups in the monool (i-1) having a polyether skeleton is preferably 5 to 95 mass%, more preferably 10 to 90 mass%, from the viewpoint that the solid electrolyte tends to become flexible and better ion conductivity is easily obtained. When the initiator is a polyoxyalkylene monool having a lower molecular weight than the target monool having a polyether skeleton, the oxyalkylene groups in the initiator are regarded as oxyalkylene groups in the obtained monool having a polyether skeleton. The ratio of the oxypropylene group is 1 It is calculated by determining the monomer composition of oxyalkylene units using H-NMR. Specifically, it can be measured by the method described in the examples.

[0043] The ratio of oxyethylene groups to the total amount of oxyalkylene groups in the monool (i-1) having a polyether skeleton is preferably 5 to 95 mass%, more preferably 10 to 90 mass%, from the viewpoint that the solid electrolyte tends to become flexible and better ion conductivity is easily obtained. When the initiator is a polyoxyalkylene monool having a lower molecular weight than the target monool having a polyether skeleton, the oxyalkylene groups in the initiator are regarded as oxyalkylene groups in the obtained monool having a polyether skeleton. The ratio of the oxyethylene groups is 1 It is calculated by determining the monomer composition of oxyalkylene units using H-NMR. Specifically, it can be measured by the method described in the examples.

[0044] Among the monools (i-1) having a polyether skeleton, a polyoxyalkylene monool having a low hydroxyl value, i.e., a high molecular weight, can be produced by ring-opening polymerization of an alkylene oxide having 3 or more carbon atoms, particularly propylene oxide, as an initiator in the presence of a composite metal cyanide complex catalyst. Examples of polyoxyalkylene monools with a low hydroxyl value include polyoxyalkylene monools with a hydroxyl value of 40 mgKOH / g or less. A polyoxyalkylene monool having an oxyethylene group and a low hydroxyl value can be produced by ring-opening polymerization of an alkylene oxide having 3 or more carbon atoms, particularly propylene oxide, using a polyoxyalkylene monool having an oxyethylene group and a high hydroxyl value, for example, a hydroxyl value of 50 mgKOH / g or more, as an initiator in the presence of a composite metal cyanide complex catalyst. In the polyether monool, the polyoxyalkylene monool having a high hydroxyl value and the polyoxyalkylene monool having a high hydroxyl value as the initiator can also be produced using an alkali catalyst such as potassium hydroxide.

[0045] In the production of polyoxyalkylene monool, the initiator and alkylene oxide introduced into the reaction system are usually those with low water content, with water removed by degassing under reduced pressure or the like. Usually, the lower the water content of the initiator in the production of polyoxyalkylene monool, the better, preferably 500 mass ppm or less, more preferably 300 mass ppm or less. When the water content is within the above range, the amount of polyoxyalkylene diol produced from water is suppressed, and as a result, the amount of by-products caused by polyoxyalkylene diol is suppressed, and it is easy to adjust the upper limit of the average number of hydroxyl groups of the obtained polyoxyalkylene monool to 1.2 or less.

[0046] The water content of the monool (i-1) having a polyether skeleton used as a raw material for the monomer 1-1 is preferably as low as possible, and is preferably 300 mass ppm or less, more preferably 250 mass ppm or less, and even more preferably 50 to 200 mass ppm, relative to the monool (i-1) having a polyether skeleton. When the water content is within the above range, the generation of by-products of the water and the isocyanate group-containing compound is reduced, and the stability of the reaction product, the monomer 1-1, is improved. Furthermore, a solid electrolyte having good flexibility is easily obtained.

[0047] The average number of hydroxyl groups in one molecule of the monool (i-1) having a polyether skeleton is preferably from 0.80 to 1.20, more preferably from 0.90 to 1.10. The hydroxyl value of the monool (i-1) having a polyether skeleton is preferably from 1.6 to 20.0 mgKOH / g, more preferably from 2.8 to 19.8 mgKOH / g, and even more preferably from 3.1 to 19.5 mgKOH / g.

[0048] The monool (i-1) having a polyether skeleton in the monomer 1-1 may be a mixture of two or more polyether monools. In this case, each monool having a polyether skeleton is preferably a polyoxyalkylene monool falling within the above category.

[0049] The monool (i-1) having a polyether skeleton is preferably at least one selected from polyether monools and polyether carbonate monools from the viewpoint of better flexibility at low temperatures and better ionic conductivity, and more preferably polyether carbonate monools from the viewpoint of electrical conductivity.

[0050] An example of the polyether monool is a compound represented by formula (1a-1).

[0051] [ka]

[0052] In formula (1a-1), R 12 , R 13 and a are the same as the same symbols in formula (1-1).

[0053] An example of the polyether carbonate monool is a compound represented by formula (1a-2).

[0054] [ka]

[0055] In formula (1a-2), R 12 , R 13 , R 14, a and b are the same as the same symbols in formula (1-2).

[0056] In polyether carbonate monool, the mole number of carbonate groups represented by -OC(=O)O- and (OR 12 The ratio of the number of moles of oxyalkylene units represented by [carbonate group / oxyalkylene unit] is not particularly limited, but is preferably 0.01 to 3, more preferably 0.01 to 2, from the viewpoint of better conductivity. The ratio of carbonate group to oxyalkylene unit in polyether carbonate monool is: 1 Determined by H-NMR. Specifically, polyether carbonate monool was dissolved in deuterated chloroform to a concentration of 10% by mass, and the solution was analyzed with a 400 MHz resolution analyzer (product name: JNM-ECZ400SJNM, manufactured by JEOL Ltd.). 1 H-NMR is measured, and calculations are made based on the peaks due to hydrogen bonded to the carbon adjacent to the carbonate group and hydrogen bonded to carbon not adjacent to the carbonate group (hydrogen in the oxyalkylene unit).

[0057] The ratio of oxypropylene groups to all oxyalkylene groups in the polyether carbonate monool represented by formula (1a-2) is preferably 5 to 95 mass%, more preferably 10 to 90 mass%, and even more preferably 10 to 50 mass%, from the viewpoint that the solid electrolyte tends to become flexible and better ion conductivity is easily obtained. When a polyoxyalkylene monool is used as an initiator, the oxyalkylene groups in the initiator are considered to be oxyalkylene groups in the obtained polyether carbonate monool. The ratio of oxyethylene groups to all oxyalkylene groups in the polyether carbonate monool represented by formula (1a-2) is preferably 5 to 95 mass%, more preferably 10 to 90 mass%, and even more preferably 50 to 90 mass%, from the viewpoint that the solid electrolyte tends to become flexible and better ion conductivity is easily obtained. When a polyoxyalkylene monool is used as an initiator, the oxyalkylene groups in the initiator are considered to be oxyalkylene groups in the obtained polyether carbonate monool.

[0058] (Compound (i-2) having a (meth)acryloyloxy group) The compound (i-2) having a (meth)acryloyloxy group is a compound having one isocyanate group per molecule and one or two (meth)acryloyloxy groups per molecule. The compound (i-2) having a (meth)acryloyloxy group is preferably a (meth)acrylate having an isocyanate group bonded to an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and more preferably an isocyanate alkyl (meth)acrylate. The number of carbon atoms in the alkylene group excluding the isocyanate group of the isocyanate alkyl group is preferably 8 or less, more preferably 4 or less.

[0059] An example of the compound (i-2) having a (meth)acryloyloxy group is a compound represented by formula (1b).

[0060] [ka]

[0061] In formula (1b), R 11 is a hydrogen atom or a methyl group. 11 is preferably a hydrogen atom. s is an integer of 1 to 4, and an integer of 1 or 2 is preferred.

[0062] Specific examples of the compound (i-2) having a (meth)acryloyloxy group include 2-isocyanate ethyl (meth)acrylate, isocyanate methyl methacrylate, etc. Commercially available products include, for example, Karenz (registered trademark; hereinafter, abbreviated) AOI and Karenz MOI (both manufactured by Showa Denko K.K.).

[0063] An example of the compound (i-2) having a (meth)acryloyloxy group is a compound represented by formula (1c).

[0064] [ka]

[0065] In formula (1c), R 11 is a hydrogen atom or a methyl group. 11 is preferably a hydrogen atom. R 14 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 14 is preferably a methyl group. t is an integer of 1 to 8. t is preferably an integer of 1 to 4, and more preferably an integer of 1 or 2. u is an integer of 0 to 4. u is preferably an integer of 0 to 2.

[0066] Specific examples of the compound (i-2) having a (meth)acryloyloxy group include 2,2-(bisacryloyloxymethyl)propyl isocyanate and 1,1-(bisacryloyloxymethyl)ethyl isocyanate (trade name "Karenz BEI", manufactured by Showa Denko K.K.), and 1,1-(bisacryloyloxymethyl)ethyl isocyanate is preferred.

[0067] Monomer 1-1 is preferably at least one selected from the group consisting of compounds represented by formula (1-1-1), compounds represented by formula (1-1-2), compounds represented by formula (1-1-3), compounds represented by formula (1-1-4), compounds represented by formula (1-1-5), and compounds represented by formula (1-1-6).

[0068] [ka]

[0069] [ka]

[0070] In formula (1-1-1), formula (1-1-2), and formula (1-1-3), R 12a are each independently one selected from an ethylene group and a propylene group, and multiple R 12b are each independently one selected from an ethylene group and a propylene group. 12b may be the same or different. 12b If are different from each other, -OR 12a -and-OR 12b The linkage of - may be random, such as -OCH2CH2- and -OCH2(CH3)CH2-. Bu is a butyl group.

[0071] In formula (1-1-1), formula (1-1-2), and formula (1-1-3), m, n1, and n2 are each independently preferably an integer of 20 to 600, more preferably an integer of 35 to 500, and even more preferably an integer of 65 to 250.

[0072] (-OR 12b -) X The number of -OCH2(CH3)CH2- units contained in [X=m, n1, n2] is preferably an integer of 1 to 600, more preferably an integer of 7 to 500, and even more preferably an integer of 13 to 250. 12b -) X The number of -OCH2CH2- units contained in [X=m, n1, n2] is preferably an integer of 0 to 599, more preferably an integer of 0 to 493, and even more preferably an integer of 0 to 237.

[0073] In formulas (1-1-4), (1-1-5), and (1-1-6), a1, a2, and a3 are each independently preferably an integer of 20 to 600, more preferably an integer of 35 to 500, and even more preferably an integer of 65 to 250. Furthermore, b1, b2, and b3 are each independently preferably an integer of 2 to 50, and more preferably an integer of 3 to 30. Bu is a butyl group.

[0074] <Monomer 1-2> Monomer 1-2 is a reaction product of (ii), which is an equimolar reaction product of a monool (ii-1) having a polyether skeleton, a diisocyanate (ii-2), and a compound (ii-3) having a (meth)acryloyloxy group, and the compound (ii-3) having a (meth)acryloyloxy group is a compound having one group reactive with an isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule.

[0075] Monomer 1-2 is preferably at least one selected from the group consisting of compounds represented by formula (2-1) and compounds represented by formula (2-2). From the viewpoint of achieving a higher ion transference number and better ionic conductivity, compounds represented by formula (2-2) are more preferred.

[0076] [ka]

[0077] [ka]

[0078] In formula (2-1) and formula (2-2), R 2 is a monovalent organic group having one or two (meth)acryloyloxy groups. R 22 is preferably an alkylene group having 2 to 8 carbon atoms, and more preferably an alkylene group having 2 to 4 carbon atoms. 22may be the same or different. Two or more types of R 22 If present, -OR 22 - The chain can be block or random. 22 is preferably one or more selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, and more preferably one or two selected from an ethylene group and a propylene group. Also, (OR 22 ) in formula (1-1) and formula (1-2) 12 As with the monomer 1-1, it is also preferred that the monomer a is a unit based on the monomer a. The preferred embodiments of the monomer a are the same as those of the monomer 1-1. R 23 is an alkyl group having 1 to 20 carbon atoms. 23 is preferably an alkyl group having 2 to 8 carbon atoms, more preferably a butyl group. R 24 is a divalent group obtained by removing two isocyanate groups from a diisocyanate. Examples of diisocyanates are described below. R 25 is a chain hydrocarbon group having 2 to 20 carbon atoms or a cyclic hydrocarbon group having a ring structure having 6 to 20 carbon atoms. 25 may be the same or different. Two or more types of R 25 When two or more (R 25 The arrangement of units represented by —O—C(═O)—O) may be random, may be block, or may be a combination of both random and block. 25 is preferably a linear or branched alkylene group having 2 to 8 carbon atoms, and more preferably an ethylene group, a 1,2-propylene group, a 1,3-propylene group, or a 1,4-butylene group. c is an integer of 20 to 600. c is preferably an integer of 35 to 500, and more preferably an integer of 65 to 250. d is preferably an integer of 2 to 50, and more preferably an integer of 3 to 30.

[0079] (Monool (ii-1) having a polyether skeleton) The monool (ii-1) having a polyether skeleton is the same as the monool (i-1) having a polyether skeleton in the monomer 1-1, and the preferred embodiments are also the same.

[0080] Examples of the monool (ii-1) having a polyether skeleton include a compound represented by formula (2a-1) and a compound represented by formula (2a-2).

[0081] [ka]

[0082] In formula (2a-1), R 22 , R 23 and c have the same meaning as the same symbols in formula (2-1).

[0083] [ka]

[0084] In formula (2a-2), R 22 , R 23 , R 25 , c and d have the same meaning as the same symbols in formula (2-2).

[0085] (Diisocyanate (ii-2)) Diisocyanate (ii-2) is a compound having two isocyanate groups in one molecule. Examples of the diisocyanate (ii-2) include non-yellowing aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and various modified products of these diisocyanates (modified products having two isocyanate groups). The diisocyanates may be used alone or in combination of two or more. As the diisocyanate (ii-2), from the viewpoint of the repeated bending durability of the solid electrolyte, one or more selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates are preferred.

[0086] Specific examples of non-yellowing aromatic diisocyanates include xylylene diisocyanate and tetramethylxylylene diisocyanate. Specific examples of the aliphatic diisocyanate include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Alicyclic diisocyanates include isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate.

[0087] The diisocyanate (ii-2) may, for example, be a compound represented by formula (2b).

[0088] [ka]

[0089] In formula (2b), R 24 has the same meaning as the same symbol in formula (2-1) and formula (2-2). As the diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate are preferred from the viewpoint of the flexibility and repeated bending durability of the solid electrolyte.

[0090] (Compound (ii-3) having a (meth)acryloyloxy group) The compound (ii-3) having a (meth)acryloyloxy group is a compound having one group reactive with an isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule. Examples of the group reactive with an isocyanate group include a hydroxyl group and an amino group having a nitrogen atom bonded to a hydrogen atom. The number of hydroxyl groups and the number of hydrogen atoms bonded to the nitrogen atom in the group reactive with an isocyanate group are preferably one each. Furthermore, the group reactive with an isocyanate group is preferably a hydroxyl group bonded to an aliphatic hydrocarbon group or an alicyclic hydrocarbon group.

[0091] The compound (ii-3) having a (meth)acryloyloxy group is preferably a hydroxyalkyl (meth)acrylate or a hydroxycycloalkyl (meth)acrylate, and particularly preferably a hydroxyalkyl (meth)acrylate having a hydroxyalkyl group with 8 or less carbon atoms.

[0092] An example of the compound (ii-3) having a (meth)acryloyloxy group is a compound represented by formula (2c).

[0093] [ka]

[0094] In formula (2c), R 21 is a hydrogen atom or a methyl group. 21 is preferably a hydrogen atom. p is an integer of 1 to 4. p is preferably an integer of 1 or 2.

[0095] Specific examples of the compound (ii-3) having a (meth)acryloyloxy group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, etc. Commercially available products include Light Ester HO-250(N), Light Ester HOP(N), Light Ester HOA(N), Light Ester HOP-A(N), Light Ester HOB(N) (all manufactured by Kyoeisha Chemical Co., Ltd.), and 4-HBA (manufactured by Osaka Organic Chemical Industry Ltd.).

[0096] An example of the compound (ii-3) having a (meth)acryloyloxy group is a compound represented by formula (2d).

[0097] [ka]

[0098] In formula (2d), R 21 is a hydrogen atom or a methyl group. 21 is preferably a hydrogen atom. R 26 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 26 is preferably a methyl group. q is an integer of 1 to 8. q is preferably an integer of 1 to 4, and more preferably an integer of 1 or 2. r is an integer of 0 to 4. r is preferably an integer of 0 to 2.

[0099] Specific examples of the compound (ii-3) having a (meth)acryloyloxy group include 2,2-(bisacryloyloxymethyl)propan-1-ol and 1,1-(bisacryloyloxymethyl)ethan-1-ol, and 1,1-(bisacryloyloxymethyl)ethan-1-ol is preferred.

[0100] <Monomer 1-3> Monomer 1-3 is a reaction product of (iii), which is an equimolar reaction product of a polyol (iii-1) having a polyether skeleton and a compound (iii-2) having a (meth)acryloyloxy group, and the compound (iii-2) having a (meth)acryloyloxy group is a compound having one isocyanate group per molecule and one or two (meth)acryloyloxy groups per molecule.

[0101] As the monomer 1-3, a compound represented by formula (III) is preferred. R 3 -NH-C(=O)-Z (III) In formula (III), R3 is a monovalent organic group having one or two (meth)acryloyloxy groups. Z is a residue of a polyol having a polyether skeleton in which one hydrogen atom has been removed from one of the hydroxyl groups in the polyol having a polyether skeleton. The polyol having a polyether skeleton is preferably at least one selected from polyether polyols and polyether carbonate polyols, from the viewpoint of better flexibility at low temperatures and better ionic conductivity, and more preferably polyether carbonate polyols from the viewpoint of electrical conductivity.

[0102] Monomer 1-3 is preferably at least one selected from the group consisting of compounds represented by formula (3-1) and compounds represented by formula (3-2). From the viewpoint of achieving a higher ion transference number and better ionic conductivity, compounds represented by formula (3-2) are more preferred.

[0103] [ka]

[0104] [ka]

[0105] In formula (3-1) and formula (3-2), R 3 is R in formula (III) 3 is the same as R 32 is preferably an alkylene group having 2 to 8 carbon atoms, and more preferably an alkylene group having 2 to 4 carbon atoms. 32 may be the same or different. Two or more types of R 32 If present, -OR 32 - The chain of R can be block or random. 32is preferably one or more selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, and more preferably one or two selected from an ethylene group and a propylene group. Also, (OR 32 ) in formula (1-1) and formula (1-2) 12 As with the monomer 1-1, it is also preferred that the monomer a is a unit based on the monomer a. The preferred embodiments of the monomer a are the same as those of the monomer 1-1. R 33 is a chain hydrocarbon group having 2 to 20 carbon atoms or a cyclic hydrocarbon group having a ring structure having 6 to 20 carbon atoms. 33 may be the same or different. Two or more types of R 33 When two or more (R 33 The arrangement of units represented by —O—C(═O)—O) may be random, may be block, or may be a combination of both random and block. 33 is preferably a linear or branched alkylene group having 2 to 8 carbon atoms, and more preferably an ethylene group, a 1,2-propylene group, a 1,3-propylene group, or a 1,4-butylene group. e is an integer of 20 to 600. e is preferably an integer of 35 to 500, and more preferably an integer of 65 to 250. f is preferably an integer of 2 to 50, and more preferably an integer of 3 to 30.

[0106] (Polyol (iii-1) having a polyether skeleton) When the monomer 1-3 is a compound represented by formula (3-1), the polyol (iii-1) having a polyether skeleton is a compound obtained by ring-opening polymerization of an initiator having an active hydrogen-containing group and having two or more active hydrogen atoms with an alkylene oxide and / or the monomer a, and has an initiator residue, a polyether chain, and hydroxyl groups corresponding to the number of active hydrogen atoms in the initiator. When the monomer 1-3 is a compound represented by formula (3-2), the polyol (iii-1) having a polyether skeleton is a compound obtained by ring-opening polymerization of an initiator having an active hydrogen-containing group and having two or more active hydrogen atoms with carbon dioxide and excess alkylene oxide and / or the monomer a, and has an initiator residue, a polyether chain, a polycarbonate chain, and hydroxyl groups corresponding to the number of active hydrogen atoms in the initiator.

[0107] The alkylene oxide is preferably an alkylene oxide having a carbon number of 2 to 4. Specific examples of the alkylene oxide having a carbon number of 2 to 4 include propylene oxide, ethylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide. Furthermore, as the monomer a, a monomer represented by the above formula (12) is preferred. Examples of the monomer represented by formula (12) include methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether, and hexyl glycidyl ether. Of these, butyl glycidyl ether and 2-ethylhexyl glycidyl ether are preferred because they result in a solid electrolyte with better flexibility.

[0108] The mass ratio of the monomer a to the total mass of the alkylene oxide and the monomer a is preferably 0 to 90 mass%, more preferably 0 to 85 mass%, and even more preferably 10 to 80 mass%, from the viewpoint of adjusting the flexibility and strength of the resulting solid electrolyte.

[0109] Examples of the active hydrogen-containing group contained in the initiator include a hydroxyl group, a carboxyl group, and an amino group having a hydrogen atom bonded to a nitrogen atom. The active hydrogen-containing group contained in the initiator is preferably a hydroxyl group, and more preferably an alcoholic hydroxyl group.

[0110] Examples of initiators having two or more active hydrogen atoms include water, polyhydric alcohols, polyhydric phenols, polycarboxylic acids, and amine compounds having two or more hydrogen atoms bonded to nitrogen atoms.The initiator is preferably water or a dihydric aliphatic alcohol, more preferably a dihydric aliphatic alcohol.In addition, a polyoxyalkylene polyol having a lower molecular weight than the polyol having the target polyether skeleton may be used as the initiator.

[0111] The carbon number of the dihydric aliphatic alcohol as the initiator is preferably 2 to 8. Specific examples of the dihydric aliphatic alcohol as the initiator include ethylene glycol, propylene glycol, polypropylene glycol such as dipropylene glycol, and 1,4-butanediol.

[0112] The oxyalkylene groups in the polyol (iii-1) having a polyether skeleton are preferably a combination of an oxypropylene group and another group, from the viewpoint of making the solid electrolyte more flexible and facilitating obtaining better ionic conductivity, and the oxyalkylene groups other than the oxypropylene group are preferably an oxyethylene group or an oxytetramethylene group, more preferably an oxyethylene group. The proportion of the oxypropylene groups to the total amount of oxyalkylene groups in the polyol (iii-1) having a polyether skeleton is preferably 5 to 95 mass%, more preferably 10 to 90 mass%. When the initiator is a polyoxyalkylene polyol having a lower molecular weight than the target polyol having a polyether skeleton, the oxyalkylene group in the initiator is considered to be the oxyalkylene group in the resulting polyol having a polyether skeleton. The ratio of the oxypropylene group is 1 It is calculated by determining the monomer composition of oxyalkylene units using H-NMR. Specifically, it can be measured by a method similar to that described in the examples.

[0113] The ratio of oxyethylene groups to the total amount of oxyalkylene groups in the polyol (iii-1) having a polyether skeleton is preferably 5 to 95% by mass, more preferably 10 to 90% by mass, from the viewpoint that the solid electrolyte tends to become flexible and better ion conductivity is easily obtained. When the initiator is a polyoxyalkylene polyol having a lower molecular weight than the target polyol having a polyether skeleton, the oxyalkylene groups in the initiator are regarded as oxyalkylene groups in the obtained polyol having a polyether skeleton. The ratio of the oxyethylene groups is 1 It is calculated by determining the monomer composition of oxyalkylene units using H-NMR. Specifically, it can be measured by a method similar to that described in the examples.

[0114] Among the polyols (iii-1) having a polyether skeleton, polyoxyalkylene polyols having a low hydroxyl value, i.e., high molecular weight, can be produced by ring-opening polymerization of an alkylene oxide having 3 or more carbon atoms, particularly propylene oxide, as an initiator in the presence of a composite metal cyanide complex catalyst. Examples of polyoxyalkylene polyols with a low hydroxyl value include polyoxyalkylene polyols with a hydroxyl value of 40 mgKOH / g or less. Among the polyols (iii-1) having a polyether skeleton, a polyoxyalkylene polyol having an oxyethylene group and a low hydroxyl value can be produced by ring-opening polymerization of an alkylene oxide having 3 or more carbon atoms, particularly propylene oxide, using a polyoxyalkylene polyol having an oxyethylene group and a high hydroxyl value, for example, a hydroxyl value of 50 mgKOH / g or more, as an initiator in the presence of a composite metal cyanide complex catalyst. Among the polyols (iii-1) having a polyether skeleton, the polyoxyalkylene polyols having a high hydroxyl value and the polyoxyalkylene polyols having a high hydroxyl value as initiators can also be produced using an alkali catalyst such as KOH.

[0115] The average number of hydroxyl groups per molecule of the polyol (iii-1) having a polyether skeleton is preferably 1.60 to 2.00, more preferably 1.70 to 2.00, and even more preferably 1.80 to 1.96. A polyether polyol having an average number of hydroxyl groups per molecule of 1.60 to 2.00 is sometimes called a polyether diol. The hydroxyl value of the polyol (iii-1) having a polyether skeleton is preferably from 1.6 to 18.1 mgKOH / g, more preferably from 2.8 to 14 mgKOH / g.

[0116] The polyol (iii-1) having a polyether skeleton may be a mixture of two or more polyether polyols, in which case each polyether polyol is preferably a polyether polyol within the above-mentioned category, and each polyether polyol is preferably a polyether diol within the above-mentioned category.

[0117] Examples of the polyol (iii-1) having a polyether skeleton include a compound represented by formula (3a-1) and a compound represented by formula (3a-2).

[0118] [ka]

[0119] [ka]

[0120] In formula (3a-1), R 32 and e have the same meaning as the same symbols in formula (3-1). 32 , R 33 , e, and f have the same meaning as the same symbols in formula (3-2).

[0121] (Compound (iii-2) having a (meth)acryloyloxy group) The compound (iii-2) having a (meth)acryloyloxy group is a compound having one isocyanate group per molecule and one or two (meth)acryloyloxy groups per molecule. The compound (iii-2) having a (meth)acryloyloxy group is the same as the compound (i-2) having a (meth)acryloyloxy group in the monomer 1-1, and the preferred embodiments are also the same.

[0122] From the viewpoint of the flexibility and repeated bending durability of the solid electrolyte, the content of the monofunctional urethane (meth)acrylate is preferably 50% by mass or more, more preferably 70 to 98% by mass, and even more preferably 80 to 95% by mass, based on the total amount of the solid electrolyte.

[0123] The glass transition temperature (Tg) of the homopolymer of the monofunctional urethane (meth)acrylate is preferably −55° C. or lower, more preferably −58° C. or lower, and even more preferably −60° C. or lower. When Tg is −55° C. or lower, the flexibility and repeated bending durability of the solid electrolyte are superior. The Tg of the homopolymer of the monofunctional urethane (meth)acrylate can be measured by a differential scanning calorimeter or a viscoelasticity measuring device.

[0124] [Second Monomer] The solid electrolyte of the present invention may contain, in addition to the first monomer, one or more second monomers selected from the reaction products (hereinafter also referred to as "monomer 2-1" and "monomer 2-2") of the following (iv) and (v). The second monomers in the solid electrolyte may be used alone or in combination of two or more. (iv) A reaction product of a polyol having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule, and the number of moles of hydroxyl groups in the polyether polyol is equal to the number of moles of the compound having a (meth)acryloyloxy group. (v) A reaction product of a polyol (A), a polyisocyanate, and a compound having a (meth)acryloyloxy group, wherein the polyol (A) is one or more selected from polyether polyols, polyether carbonate polyols, polyester polyols, poly(meth)acrylic polyols, polycarbonate polyols, castor oil-based polyols, and polyolefin polyols, the compound having a (meth)acryloyloxy group is a compound having one group reactive with an isocyanate group in one molecule and one or two (meth)acryloyloxy groups in one molecule, and the total number of moles of hydroxyl groups in the polyol (A) and groups reactive with an isocyanate group in the compound having a (meth)acryloyloxy group is equal to the number of moles of isocyanate groups in the polyisocyanate.

[0125] The second monomer is a polyfunctional urethane (meth)acrylate having two or more (meth)acryloyloxy groups and can act as a cross-linking monomer that cross-links the first monomer. A solid electrolyte containing the first monomer and the second monomer has excellent flexibility.

[0126] The second monomer preferably has a molecular weight of 6,000 to 60,000, more preferably 8,000 to 40,000, and even more preferably 10,000 to 34,000. When the molecular weight is 6,000 or more, the flexibility of the solid electrolyte is easily obtained and the conductivity can be improved, and when the molecular weight is 60,000 or less, the toughness of the cured film is excellent.

[0127] <Monomer 2-1> Monomer 2-1 is a reaction product of (iv), which is a reaction product of a polyol (iv-1) having a polyether skeleton and a compound (iv-2) having a (meth)acryloyloxy group, and the compound (iv-2) having a (meth)acryloyloxy group has one isocyanate group per molecule and one or two (meth)acryloyloxy groups per molecule, and the number of moles of hydroxyl groups in the polyol (iv-1) having a polyether skeleton is equal to the number of moles of the compound (iv-2) having a (meth)acryloyloxy group.

[0128] As the monomer 2-1, a compound represented by formula (IV) is preferred. R 4 -NHC(=O)-ZC(=O)NH-R 4 (IV) In formula (IV), R 4 is a monovalent organic group having one or two (meth)acryloyloxy groups. Z is a residue of polyol (iv-1) having a polyether skeleton obtained by removing two hydrogen atoms from two hydroxyl groups in polyol (iv-1) having a polyether skeleton.

[0129] Monomer 2-1 is preferably at least one selected from the group consisting of compounds represented by formula (4-1) and compounds represented by formula (4-2). From the viewpoint of achieving a higher ion transference number and better ionic conductivity, compounds represented by formula (4-2) are more preferred.

[0130] [ka]

[0131] [ka]

[0132] In formula (4-1) and formula (4-2), R 4 is R in formula (IV) 4 is the same as: R 42 is preferably an alkylene group having 2 to 8 carbon atoms, and more preferably an alkylene group having 2 to 4 carbon atoms. 42 may be the same or different. Two or more types of R 42 If present, -OR 42 - The chain of R can be block or random. 42 is preferably one or more selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, and more preferably one or two selected from an ethylene group and a propylene group. Also, (OR 42 ) in formula (1-1) and formula (1-2) 12 As with the monomer 1-1, it is also preferred that the monomer a is a unit based on the monomer a. The preferred embodiments of the monomer a are the same as those of the monomer 1-1. R 43 is a chain hydrocarbon group having 2 to 20 carbon atoms or a cyclic hydrocarbon group having a ring structure having 6 to 20 carbon atoms. 43 may be the same or different. Two or more types of R 43 When two or more (R 43 The arrangement of units represented by —O—C(═O)—O) may be random, may be block, or may be a combination of both random and block. 43 is preferably a linear or branched alkylene group having 2 to 8 carbon atoms, and more preferably an ethylene group, a 1,2-propylene group, a 1,3-propylene group, or a 1,4-butylene group. g is an integer of 20 to 600. g is preferably an integer of 35 to 500, and more preferably an integer of 65 to 250. h is preferably an integer of 2 to 50, and more preferably an integer of 3 to 30.

[0133] The polyol (iv-1) having a polyether skeleton is the same as the polyol (iii-1) having a polyether skeleton in the monomer 1-3, and the preferred embodiments are also the same.

[0134] The compound (iv-2) having a (meth)acryloyloxy group is the same as the compound (i-2) having a (meth)acryloyloxy group in the monomer 1-1, and the preferred embodiments are also the same.

[0135] <Monomer 2-2> Monomer 2-2 is a reaction product of (v), which is a reaction product of polyol (A), polyisocyanate (v-1), and compound (v-2) having a (meth)acryloyloxy group, in which polyol (A) is one or more selected from polyether polyols, polyether carbonate polyols, polyester polyols, poly(meth)acrylic polyols, polycarbonate polyols, castor oil-based polyols, and polyolefin polyols, and compound (v-2) having a (meth)acryloyloxy group is a compound having one group reactive with an isocyanate group per molecule and one or two (meth)acryloyloxy groups per molecule, and the total number of moles of hydroxyl groups in polyol (A) and groups reactive with isocyanate groups in compound (v-2) having a (meth)acryloyloxy group is equal to the number of moles of isocyanate groups in polyisocyanate (v-1).

[0136] Monomer 2-2 is preferably at least one selected from the group consisting of compounds represented by formula (5-1) and compounds represented by formula (5-2). From the viewpoint of achieving a higher ion transference number and better ionic conductivity, compounds represented by formula (5-2) are more preferred.

[0137] [ka]

[0138] [ka]

[0139] In formula (5-1) and formula (5-2), R 5is a monovalent organic group having one or two (meth)acryloyloxy groups. R 52 is preferably an alkylene group having 2 to 8 carbon atoms, and more preferably an alkylene group having 2 to 4 carbon atoms. 52 may be the same or different. Two or more types of R 52 If present, -OR 52 -The chain can be block or random. 52 is preferably one or more selected from an ethylene group, a propylene group, a 1,2-dimethylethylene group, and a 1-ethylethylene group, and more preferably one or two selected from an ethylene group and a propylene group. Also, (OR 52 ) in formula (1-1) and formula (1-2) 12 As with the monomer 1-1, it is also preferred that the monomer a is a unit based on the monomer a. The preferred embodiments of the monomer a are the same as those of the monomer 1-1. R 54 is a divalent group obtained by removing two isocyanate groups from a diisocyanate. The diisocyanate is the same as the diisocyanate in Monomer 1-2, and the preferred embodiments are also the same. R 53 is a chain hydrocarbon group having 2 to 20 carbon atoms or a cyclic hydrocarbon group having a ring structure having 6 to 20 carbon atoms. 53 may be the same or different. Two or more types of R 53 When two or more (R 53 The arrangement of units represented by —O—C(═O)—O) may be random, may be block, or may be a combination of both random and block. 53 is preferably a linear or branched alkylene group having 2 to 8 carbon atoms, and more preferably an ethylene group, a 1,2-propylene group, a 1,3-propylene group, or a 1,4-butylene group. i is an integer of 20 to 600. i is preferably an integer of 35 to 500, and more preferably an integer of 65 to 250. j is preferably an integer of 2 to 50, and more preferably an integer of 3 to 30.

[0140] Among the polyols (A), the polyether polyols are the same as the polyether polyols in Monomer 1-3, and the preferred embodiments are also the same.Furthermore, the polyether carbonate polyols are the same as the polyether carbonate polyols in Monomer 1-3, and the preferred embodiments are also the same. In the polyol (A), polyether polyols, polyester polyols, poly(meth)acrylic polyols, polycarbonate polyols, castor oil-based polyols, and polyolefin polyols described in

[0016] to

[0028] of JP 2020-37689 A can be used without any particular limitation. The polyether polyol may be a polymer polyol in which a polymer having units based on a (meth)acrylate monomer is dispersed in a polyether polyol. The polymer polyol may be a commercially available product, such as the "ULTIFLOW (registered trademark)" series or the "SHARPFLOW (registered trademark)" series (both manufactured by Sanyo Chemical Industries, Ltd.), or the "EXCENOL (registered trademark)" series (manufactured by AGC Inc.). Commercially available polyether carbonate polyols include, for example, the "Converge" series (manufactured by Saudi Aramco).

[0141] The polyisocyanate (v-1) is a compound having two or more isocyanate groups in one molecule. The polyisocyanate is preferably a compound having two or three isocyanate groups in one molecule, and more preferably a diisocyanate. The diisocyanate is the same as the diisocyanate (ii-2) in the monomer 1-2, and the preferred embodiments are also the same. Specific examples of the polyisocyanate (v-1) include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, isophorone diisocyanate, and polyisocyanate. From the viewpoint of ease of adjusting the elongation and strength of the solid electrolyte, hexamethylene diisocyanate or isophorone diisocyanate is preferred.

[0142] [Contents of first monomer and second monomer] The content of the first monomer relative to 100 parts by mass of the solid electrolyte is preferably 50 parts by mass or more, more preferably 70 to 98 parts by mass, and even more preferably 80 to 95 parts by mass, from the viewpoints of flexibility and repeated bending durability of the solid electrolyte. Monomer 1-1, Monomer 1-2, and Monomer 1-3 may be used singly or in combination of two or more. The first monomer more preferably includes one or more selected from Monomer 1-1 and Monomer 1-2. From the viewpoint of the flexibility of the solid electrolyte, the total content of Monomer 1-1 and Monomer 1-2 per 100 parts by mass of the first monomer is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, and particularly preferably 100 parts by mass. In this case, the content of Monomer 1-1 is preferably 50 to 100 parts by mass per 100 parts by mass of the total content of Monomer 1-1 and Monomer 1-2.

[0143] When the solid electrolyte contains a second monomer, from the viewpoint of the flexibility and repeated bending durability of the solid electrolyte, the content of the second monomer per 100 parts by mass of the solid electrolyte is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less.

[0144] [Electrolyte salt] The electrolyte salt can be a metal salt, and various metal salts consisting of electrically positively charged compounds and electrically negatively charged compounds can be used. Specific examples of metal salts include LiBF4, LiPF6, LiNbF6, LiAsF6, LiNH2, LiF, LiCl, LiSCN, LiCF3SO3, LiC6H5SO3, LiBr, LiI, LiCN, LiClO4, LiNO3, and LiN(CF3SO2). 2、 Examples of such an electrolyte include C6H5COOLi, MgN(CF3SO2)2, NaCl, NaBr, NaF, NaI, NaClO4, NaCN, NaN(CF3SO2)2, NaPF6, and NaN(FSO2)2. Among these, at least one selected from the group consisting of LiBF4, LiPF6, LiClO4, LiN(CF3SO2)2, MgN(CF3SO2)2, NaPF6, NaN(CF3SO2)2, and NaN(FSO2)2 is preferred, as it is more likely to be dispersed more uniformly in the polymer electrolyte and to have good ionic conductivity, and LiBF4, LiPF6, LiN(CF3SO2)2, MgN(CF3SO2)2, and NaPF6 are more preferred.

[0145] The electrolyte salt is preferably uniformly dispersed in the electrolyte containing the monofunctional urethane (meth)acrylate, and the dispersion method may involve directly mixing the solid salt into the electrolyte or dispersing the solid salt in a solvent or the like and then mixing the solid salt.

[0146] The content of the electrolyte salt is preferably 0.01 to 50 mass % relative to the solid electrolyte, more preferably 0.1 to 30 mass %, and even more preferably 0.5 to 20 mass %, in order to improve ionic conductivity.

[0147] [Solid electrolyte manufacturing method] The method for producing a solid electrolyte of the present invention involves irradiating a composition containing a monofunctional urethane (meth)acrylate, which is one or more monomers selected from reaction products of compounds containing a predetermined (meth)acryloyloxy group, and an electrolyte salt with light having a wavelength of 300 to 410 nm to cure the composition. The monofunctional urethane (meth)acrylate and the electrolyte salt can be the same as those described in the section [Solid Electrolyte] above. The composition may further contain a photopolymerization initiator.

[0148] From the viewpoint of controlling the polymerization reaction, the photopolymerization initiator is preferably one that can be used with ultraviolet irradiation at a wavelength of 410 nm or less. The photopolymerization initiator may be used alone or in combination of two or more. Examples of the photopolymerization initiator include those described in paragraphs

[0147] to

[0151] of WO 2018 / 173896. The photopolymerization initiator is preferably a hydrogen abstraction photopolymerization initiator in which a photoexcited initiator and a hydrogen donor in the system form an exciplex, transferring hydrogen from the hydrogen donor. Specific examples of hydrogen abstraction photopolymerization initiators include benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4-(meth)acryloyloxybenzophenone, 4-[2-((meth)acryloyloxy)ethoxy]benzophenone, 4-(meth)acryloyloxy-4'-methoxybenzophenone, methyl 2-benzoylbenzoate, and methyl benzoylformate. Furthermore, as the photopolymerization initiator, from the viewpoint of high sensitivity to light, an acylphosphine oxide-based photoinitiator such as phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, or bis(2,6-dimethoxybenzoyl)2,4,4-trimethylpentylphosphine oxide is preferred. The photopolymerization initiator may be used alone or in combination of two or more kinds.

[0149] From the viewpoint of ensuring appropriate progress of curing accompanying polymerization of the composition, the content of the photopolymerization initiator in the composition is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.2 to 6 parts by mass, relative to 100 parts by mass of the first monomer and the second monomer in total.

[0150] In addition to the above components, the composition may contain other components that are generally blended into this type of material, provided that the effects of the present invention are not impaired. Examples of other components include monomers other than the first and second monomers (hereinafter also referred to as "other monomers"), antioxidants, light stabilizers, photosensitizers, flame retardants, etc. These other components are blended in the composition in a content range that does not impair the effects of the present invention.

[0151] <Other monomers> The other monomer is a compound that copolymerizes with the first monomer (when the solid electrolyte contains a second monomer, with the first monomer and the second monomer), and may be used alone or in combination of two or more types. From the viewpoint of ease of copolymerization with the first monomer and the second monomer, examples of the other monomer include (meth)acrylates such as alkyl (meth)acrylates, hydroxyl group-containing (meth)acrylates, and amino group-containing (meth)acrylates. Examples of the alkyl(meth)acrylate include alkyl(meth)acrylates having a linear or branched alkyl group, and the alkyl group preferably has 1 to 18 carbon atoms, more preferably 1 to 14 carbon atoms, and even more preferably 1 to 10 carbon atoms. Specific examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-undecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate. Examples of hydroxyl group-containing (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, caprolactone-modified (meth)acrylate, polyoxyethylene (meth)acrylate, and polyoxypropylene (meth)acrylate. Examples of amino group-containing (meth)acrylates include aminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, and dimethylaminomethyl (meth)acrylate.

[0152] The other monomer may be a crosslinkable monomer having two or more functional groups capable of crosslinking the first monomer. The crosslinkable monomer may be used alone or in combination of two or more. The functional group of the crosslinkable monomer is preferably at least one selected from the group consisting of (meth)acryloyloxy, epoxy, isocyanate, carboxy, hydroxy, carbodiimide, oxazoline, aziridine, vinyl, amino, imino, and amide groups. The functional group may be protected with a deprotectable protecting group. The number of functional groups in one molecule of the crosslinkable monomer is preferably 2 to 4, more preferably 2 or 3.

[0153] When a crosslinkable monomer is blended, the content of the crosslinkable monomer in the composition is preferably 1 to 50 parts by mass, more preferably 2 to 45 parts by mass, and even more preferably 3 to 40 parts by mass, per 100 parts by mass of the first monomer (or the first monomer and the second monomer, if the composition contains a second monomer), from the viewpoint of flexibility of the resulting solid electrolyte.

[0154] In the composition, the total content of the monofunctional urethane (meth)acrylate and the electrolyte salt is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0155] The composition is prepared by curing a mixture of a monofunctional urethane (meth)acrylate, an electrolyte salt, a photopolymerization initiator which is added as needed, and other components to obtain a solid electrolyte. The order of mixing the components when preparing the composition is not particularly limited, and the components may be mixed together before being irradiated with ultraviolet light. The components of the composition may be mixed in advance or immediately before curing. For example, the photopolymerization initiator may be added to a premix in which components other than the photopolymerization initiator are mixed in advance, immediately before curing.

[0156] The composition may be molded into a desired shape and then cured by irradiating it with ultraviolet light. Methods for forming the composition into a desired shape include, for example, coating the composition on a substrate, extrusion molding, and pouring the composition into a mold. The amount of ultraviolet light irradiated when photocuring the composition is 0.1 to 5 J / cm 2 is preferable, and 0.3 to 4 J / cm 2 More preferably, 0.5 to 3 J / cm 2 The above irradiation dose is more preferably 0.1 J / cm. 2 If the curing rate is above 5 J / cm, sufficient curing can be achieved. 2 When the curing rate is less than this, the desired curability can be obtained in a shorter time.

[0157] The solid electrolyte obtained in this manner has excellent ionic conductivity and flexibility at low temperatures, and excellent durability against repeated bending. The glass transition temperature (Tg) of the solid electrolyte is preferably less than 0°C, more preferably less than -60°C, and even more preferably less than -65°C. When Tg is less than 0°C, the solid electrolyte has excellent flexibility at low temperatures and durability against repeated bending. The lower limit of Tg of the solid electrolyte is preferably -85°C or higher, since stable conductivity can be easily obtained. The Tg of the solid electrolyte can be measured in accordance with JIS K7121:2012, specifically by the method described in the examples.

[0158] [battery] The battery of the present invention includes the above-described solid electrolyte, and therefore has excellent ionic conductivity and flexibility at low temperatures, as well as excellent durability against repeated bending, making it possible to form a flexible battery. The battery of the present invention can be obtained by joining various known positive and negative electrode materials to the solid electrolyte. Positive electrode materials include LiMnO2, LiMn2O4, LiCoO2, Li2Cr2O7, LiNiO2, and Li2CrO4. Negative electrode materials include hard carbon, soft carbon, and lithium metal. Negative electrode materials can be appropriately used with microstructures such as laminated, spherical, fibrous, spiral, and fibril, and can be in the form of flat plate, corrugated plate, rod, or powder.

[0159] The exterior packaging material for packaging the battery can be aluminum foil, aluminum-deposited organic film, etc. Various known organic film materials can be used, and specific examples include polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, nylon, and polyethylene tetrafluorate.

[0160] [Goods] The article of the present invention includes the battery described above. Examples of such articles include flexible devices such as wearable devices, electrochromic displays, and the like. [Example]

[0161] The present invention will be specifically described below based on examples, but the present invention is not limited to the following examples.

[0162] [Preparation of Composition] Compositions for producing solid electrolytes were produced according to the following synthesis examples and production examples.

[0163] [Measurement of number average molecular weight] The number average molecular weight of the products obtained in the synthesis examples was measured by gel permeation chromatography (GPC) under the following measurement conditions. <Measurement conditions> Equipment used: "HLC-8120GPC", manufactured by Tosoh Corporation Columns used: The following two columns are connected in series: TSKgel (registered trademark) G7000H XL ", manufactured by Tosoh Corporation, 1 bottle "TSKgel (registered trademark) GMH XL ", manufactured by Tosoh Corporation, 2 bottles Column temperature: 40℃ Detector: Refractive index (RI) Eluent: tetrahydrofuran ·Flow rate: 0.8mL / min Sample concentration: 0.5% by mass Sample injection volume: 100 μL Standard sample: Polystyrene

[0164] [Oxyethylene group content (EO content) and oxypropylene group content (PO content)] The content ratio of oxyethylene groups (ethylene oxide unit content) and the content ratio of oxypropylene groups (propylene oxide unit content) relative to the total amount of oxyalkylene groups for Monools 1 to 3 obtained in the Production Examples are as follows:1 The monomer composition of the oxyalkylene units was determined using H-NMR, and the EO content and PO content were calculated from the area ratio of the methyl group signal in the propylene oxide unit to the methylene group signals in the propylene oxide unit and ethylene oxide unit.

[0165] [Raw material compound] Details of the raw material compounds used in the production examples and synthesis examples are as follows. Initiator A: Polyoxypropylene monool obtained by addition reaction of propylene oxide (hereinafter referred to as "PO") to n-butanol using KOH catalyst until the molecular weight reaches 400. Initiator B: Polyoxypropylene monool obtained by addition reaction of PO to n-butanol using KOH catalyst until the molecular weight reaches 3,300 DMC-TBA catalyst: Zinc hexacyanocobaltate-tert-butyl alcohol complex AOI: 2-acryloyloxyethyl isocyanate; Karenz AOI, manufactured by Showa Denko K.K.

[0166] [Products containing monofunctional urethane (meth)acrylate] (A-1): Product containing monofunctional urethane acrylate obtained in Synthesis Example 1 (A-2): Product containing monofunctional urethane acrylate obtained in Synthesis Example 2 (A-3): Product containing monofunctional urethane acrylate obtained in Synthesis Example 3

[0167] [(Meth)acrylate] (B-1): Polyethylene glycol monoacrylate; "Blenmer (registered trademark) AE-200" manufactured by NOF Corporation; number average molecular weight: approximately 200 (catalog value) (B-2): Methoxypolyethylene glycol methacrylate; "Blenmer (registered trademark) PME-1000" manufactured by NOF Corporation; number average molecular weight approximately 1,000 (catalog value) (B-3): Methoxypolyethylene glycol methacrylate; "Blenmer (registered trademark) PME-4000" manufactured by NOF Corporation; number average molecular weight: approximately 4,000 (catalog value)

[0168] [Electrolyte salt] (C-1): Lithium bis(trifluoromethanesulfonyl)imide; "LiTFSI (LiN(CF3SO2)2)", manufactured by Morita Chemical Industry Co., Ltd. (C-2): Magnesium bis(trifluoromethanesulfonyl)imide; "MgTFSI (MgN(CF3SO2)2)", manufactured by Tokyo Chemical Industry Co., Ltd. (C-3): Sodium hexafluorophosphate; "NaPF6 (NaPF6)", manufactured by Tokyo Chemical Industry Co., Ltd.

[0169] [Photopolymerization initiator] (D-1): Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; "Irgacure (registered trademark) 819" manufactured by BASF

[0170] [Manufacturing Example 1] A pressure-resistant reactor equipped with a stirrer and a nitrogen inlet tube was charged with 0.4 g of DMC-TBA catalyst and 538 g of initiator A, and then, under a nitrogen atmosphere, 1,120 g of PO and 6,347 g of ethylene oxide (EO) were added at a constant rate over 7 hours at 130°C. After confirming that the internal pressure of the pressure-resistant reactor had stopped decreasing, 8,000 g of polyoxyalkylene monol (Monool 1) was obtained, having a hydroxyl value of 9.6 mgKOH / g (hydroxyl value-based molecular weight: 5,840), an EO content of 80% by mass, and a PO content of 20% by mass.

[0171] [Manufacturing Example 2] A pressure-resistant reactor equipped with a stirrer and a nitrogen inlet tube was charged with 0.4 g of DMC-TBA catalyst and 1,220 g of initiator B, and then 2,109 g of PO and 735 g of EO were added at a constant rate over 7 hours at 130°C under a nitrogen atmosphere. After confirming that the internal pressure of the pressure-resistant reactor had stopped decreasing, 4,064 g of polyoxyalkylene monol (monool 2) was obtained, having a hydroxyl value of 5.2 mgKOH / g (hydroxyl value-based molecular weight: 10,730), an EO content of 18% by mass, and a PO content of 82% by mass.

[0172] [Manufacturing Example 3] 48 g of initiator A was placed in a reactor, and the reactor was connected to a carbon dioxide cylinder. The gas phase in the reactor was replaced with carbon dioxide. Next, while the reactor was constantly pressurized with carbon dioxide to 1.5 MPa, 0.8 g of DMC-TBA catalyst was added, and 291 g of EO was added at a constant rate over 5 hours. The EO and carbon dioxide reacted to produce 400 g of polyether carbonate monool (monool 3) with a hydroxyl value of 19.32 mg KOH / g (hydroxyl value-based molecular weight: 2,900), an EO content of 88% by mass, and a PO content of 12% by mass. The obtained monool 3 was dissolved in deuterated chloroform to a concentration of 10% by mass, and analyzed by a 400 MHz resolution analyzer (JNM-ECZ400SJNM, manufactured by JEOL Ltd.). 1 H-NMR was measured. From the obtained results, the peak due to the carbonate group [-OC(=O)O-] in the polyether carbonate monool and the peak due to the EO unit were identified, and the copolymer composition ratio in the polymer was calculated from their areas. The proportion of carbonate groups in monool 3 was 2.3 mass%.

[0173] [Synthesis Example 1] 292.9 g of Monool 1 (average hydroxyl group number 1.08) obtained in Production Example 1, 7.08 g of AOI (NCO index 100), and 0.024 g of a 25% by weight toluene solution of bismuth 2-ethylhexanoate were added to a reaction vessel equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at 70°C for 3 hours to obtain a product containing a monofunctional urethane acrylate (number average molecular weight 8,400). Furthermore, 0.3% by weight of IRGACURE 819 was added as a photoinitiator to the resulting composition containing the monofunctional urethane acrylate to obtain a homopolymer. The glass transition temperature of the resulting homopolymer was measured using the same method as described below for glass transition temperature measurement. The resulting glass transition temperature was −73°C.

[0174] [Synthesis Example 2] In a reaction vessel equipped with a stirrer and a nitrogen inlet tube, 293.7 g of Monool 2 (average hydroxyl group number 1.01) obtained in Production Example 2, 6.27 g of AOI (NCO index 100), and 0.024 g of a 25% by mass toluene solution of bismuth 2-ethylhexanoate were added and stirred at 70°C for 3 hours to obtain a product containing a monofunctional urethane acrylate (number average molecular weight 17,750). A homopolymer was obtained in the same manner as in Synthesis Example 1, and the glass transition temperature was measured. The glass transition temperature of the obtained homopolymer was -74°C.

[0175] [Synthesis Example 3] Into a reaction vessel equipped with a stirrer and a nitrogen inlet tube, 143.0 g of Monool 3 (average number of hydroxyl groups: 1.01) obtained in Production Example 3, 6.95 g of AOI (NCO index: 100), and 0.012 g of a 25 mass % toluene solution of bismuth 2-ethylhexanoate were added, and the mixture was stirred at 70°C for 3 hours to obtain a product containing a monofunctional urethane acrylate (number average molecular weight: 2,780).

[0176] [Example 1] The composition of Example 1 was prepared by mixing 90 parts by mass of (A-1) the product containing the monofunctional urethane acrylate obtained in Synthesis Example 1, 10 parts by mass of (C-1) LiTFSI, and 0.3 parts by mass of (D-1) a photopolymerization initiator.

[0177] [Example 2] The composition of Example 2 is prepared in the same manner as in Example 1, except that the product containing the monofunctional urethane acrylate (A-2) obtained in Synthesis Example 2 is used as the component (A) instead of the component (A-1).

[0178] [Example 3] The composition of Example 3 is prepared in the same manner as in Example 1, except that the product containing the monofunctional urethane acrylate (A-3) obtained in Synthesis Example 3 is used as the component (A) instead of the component (A-1).

[0179] [Example 4] The composition of Example 4 is prepared by mixing 90 parts by mass of (B-1) Blenmer (registered trademark) AE-200, 10 parts by mass of (C-1) LiTFSI, and 0.3 parts by mass of (D-1) photopolymerization initiator.

[0180] [Example 5] The composition of Example 5 is prepared in the same manner as in Example 4, except that (B-2) Blenmar (registered trademark) PME-1000 is used instead of component (B-1).

[0181] [Example 6] The composition of Example 6 is prepared in the same manner as in Example 4, except that (B-3) Blenmar (registered trademark) PME-4000 is used instead of component (B-1).

[0182] [Example 7] The composition of Example 7 was prepared by mixing 85 parts by mass of (A-1) the product containing the monofunctional urethane acrylate obtained in Synthesis Example 1, 15 parts by mass of (C-1) LiTFSI, and 0.3 parts by mass of (D-1) a photopolymerization initiator.

[0183] [Example 8] The composition of Example 8 was prepared by mixing 85 parts by mass of (A-1) the product containing the monofunctional urethane acrylate obtained in Synthesis Example 1, 15 parts by mass of (C-2) MgTFSI, and 0.3 parts by mass of (D-1) the photopolymerization initiator.

[0184] [Example 9] The composition of Example 9 was prepared by mixing 85 parts by mass of (A-1) the product containing the monofunctional urethane acrylate obtained in Synthesis Example 1, 15 parts by mass of (C-3) NaPF6, and 0.3 parts by mass of (D-1) a photopolymerization initiator.

[0185] 〔evaluation〕 Test specimens were prepared using the compositions produced in Examples 1 to 9, and were evaluated by the following tests. The evaluation results are shown in Table 1. Examples 1 to 3 and Examples 7 to 9 are working examples, and Examples 4 to 6 are comparative examples. (1) Ionic conductivity Each of the compositions of Examples 1 to 9 was poured into a cylindrical silicone mold having a diameter of 5 mm and a thickness of 2 mm. Then, in a nitrogen environment, a conveyor-type UV irradiator (manufactured by ORC) was used to irradiate the silicone rubber with an HgXe lamp and an irradiance of 100 mW / cm. 2 , cumulative light intensity 1J / cm 2 The specimen is cured under the conditions below. The ionic conductivity (σ) of the obtained specimen is evaluated by preparing a measurement cell by sandwiching the specimen between a pair of electrodes (made of stainless steel: thickness 4 mm x diameter 20 mm), measuring the complex impedance using this, and calculating the logarithm of the ionic conductivity (log(σ)) using the following formula. log(σ)=log(d / (R×A)) (In the formula, R is the bulk resistance value, d is the thickness of the test piece, and A is the area of ​​the electrode.) When complex impedance is measured, it exhibits frequency dependence due to the migration of ions along the potential gradient, as well as the charging and discharging of the electric double layer and electrode reactions. This frequency dependence is plotted on a plane with the real part on the horizontal axis and the imaginary part on the vertical axis (Cole-Cole plot), and the value of the equivalent circuit that explains the trajectory (resistance value) is determined. Measurements are performed at temperatures of 0°C and 23°C. The logarithm of ionic conductivity (log(σ)) is evaluated according to the following criteria. <Evaluation criteria> A: log(σ) is -4.5 or more B: log(σ) is between -5.5 and -4.5 C: log(σ) is less than -5.5

[0186] (2) Glass transition temperature Each of the compositions of Examples 1 to 9 was poured into a cylindrical silicone mold having a diameter of 5 mm and a thickness of 2 mm. Then, in a nitrogen environment, a conveyor-type UV irradiator (manufactured by ORC) was used to irradiate the silicone rubber with an HgXe lamp and an irradiance of 100 mW / cm. 2 , cumulative light intensity 1J / cm 2 The cured product is then cured under the following conditions: 10 mg is sampled and used as a test specimen. The glass transition temperature of the obtained test specimen is measured using a differential scanning calorimeter (EXSTAR 6000 DSC6100, manufactured by Seiko Instruments Inc.). An aluminum pan is used as the sample container. The measurement conditions are a temperature range of -100°C to +80°C and a heating rate of 3°C / min. The glass transition temperature is evaluated according to the following criteria. <Evaluation criteria> A: Below -60°C B: -60℃ or higher and below 0℃

[0187] (3) Repeated bending test Each of the compositions in Examples 1 to 9 was applied to a polyethylene terephthalate (PET) film (Lumirror S10, manufactured by Toray Industries, Inc., thickness 50 μm) using a doctor blade so that the thickness of the cured composition was 25 μm, and then a polyethylene film was overlaid. Next, in a nitrogen environment, a conveyor-type UV irradiator (manufactured by ORC) was used to irradiate the film with an HgXe lamp at an illuminance of 100 mW / cm. 2 , cumulative light intensity 1J / cm 2 The solid electrolyte is formed by hardening under the conditions. The polyethylene film is peeled off to prepare the test specimen. Each test specimen is cut to prepare a test piece measuring 50 mm in width, 150 mm in length, and 75 μm in thickness. The test was conducted by repeatedly bending the test piece into a U-shape at halfway along its length with the PET film side facing outward using a U-shaped planar bending tester (DLDM111LH, manufactured by Yuasa System Co., Ltd.; test conditions: room temperature (25°C), bending radius 2 mm, bending at 180°C and releasing counted as one cycle, repeated 100,000 times at a speed of 60 cycles / min). The appearance of the test piece after the test is visually observed and evaluated according to the following evaluation criteria: A or B indicates no practical problems and excellent durability to repeated bending, while C indicates insufficient durability to repeated bending and is not suitable for practical use. <Evaluation criteria> A: No peeling, lifting or cracking occurs, and there is absolutely no change in appearance. B: Slight peeling, lifting, or cracking occurred. C: One or more of peeling, lifting, and cracking occurred significantly.

[0188] [Table 1]

[0189] The cured products obtained by curing the compositions of Examples 1 to 3 and 7 to 9 have excellent ionic conductivity at low temperatures, and also have flexibility and durability against repeated bending.

Claims

1. A solid electrolyte obtained by curing a composition containing a monofunctional urethane (meth)acrylate and an electrolyte salt, wherein the monofunctional urethane (meth)acrylate is one or more monomers selected from the reaction products of the following (i), (ii), and (iii), and the molecular weight of the monofunctional urethane (meth)acrylate is 2,500 to 30,000: (i) A reaction product of an equimolar reaction of a monool having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group per molecule and one (meth)acryloyloxy group per molecule. (ii) A reaction product of an equimolar reaction of a monool having a polyether skeleton, a diisocyanate, and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one group reactive with an isocyanate group in one molecule and one (meth)acryloyloxy group in one molecule. (iii) A reaction product of an equimolar reaction of a polyol having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group per molecule and one (meth)acryloyloxy group per molecule.

2. The solid electrolyte according to claim 1 , wherein the monool having a polyether skeleton is at least one selected from the group consisting of polyether monools and polyether carbonate monools.

3. The solid electrolyte according to claim 1 or 2, wherein the monofunctional urethane (meth)acrylate is a reaction product of the (i).

4. 2. The solid electrolyte according to claim 1, wherein the polyol having a polyether skeleton is at least one selected from the group consisting of polyether polyols and polyether carbonate polyols.

5. The solid electrolyte according to any one of claims 1 to 4, wherein the monool having a polyether skeleton and the polyol having a polyether skeleton have an oxyalkylene group.

6. 6. The solid electrolyte according to claim 5, wherein a ratio of oxyethylene groups to a total amount of oxyalkylene groups in the monool having a polyether skeleton or the polyol having a polyether skeleton is 5 to 95 mass%.

7. 7. The solid electrolyte according to claim 5, wherein a ratio of oxypropylene groups to a total amount of oxyalkylene groups in the monool having a polyether skeleton or the polyol having a polyether skeleton is 5 to 95 mass%.

8. The solid electrolyte according to any one of claims 1 to 7, wherein the glass transition temperature of a homopolymer of the monofunctional urethane (meth)acrylate is -55°C or lower.

9. 9. The solid electrolyte according to claim 1, wherein the content of the electrolyte salt is 0.01 to 50 mass% based on the solid electrolyte.

10. The electrolyte salt is LiBF ４ , LiPF ６ , LiClO ４ , LiN(CF ３ SO ２ ) ２ , MgN(CF ３ SO ２ ) ２ , NaPF ６、 NaN(CF ３ SO ２ ) ２ and NaN(FSO ２ ) ２ The solid electrolyte according to any one of claims 1 to 9, which is at least one selected from the group consisting of:

11. A battery comprising the solid electrolyte according to any one of claims 1 to 10.

12. An article comprising the battery of claim 11.

13. A composition comprising a monofunctional urethane (meth)acrylate and an electrolyte salt, wherein the monofunctional urethane (meth)acrylate is one or more monomers selected from the reaction products of the following (i), (ii), and (iii), and the molecular weight of the monofunctional urethane (meth)acrylate is 2,500 to 30,000: (i) A reaction product of an equimolar reaction of a monool having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group per molecule and one (meth)acryloyloxy group per molecule. (ii) A reaction product of an equimolar reaction of a monool having a polyether skeleton, a diisocyanate, and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one group reactive with an isocyanate group in one molecule and one (meth)acryloyloxy group in one molecule. (iii) A reaction product of an equimolar reaction of a polyol having a polyether skeleton and a compound having a (meth)acryloyloxy group, wherein the compound having a (meth)acryloyloxy group has one isocyanate group per molecule and one (meth)acryloyloxy group per molecule.

14. A method for producing a solid electrolyte, comprising irradiating the composition according to claim 13 with light having a wavelength of 300 to 410 nm to cure it.

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