Polyamide-imide resin composition, polyamide-imide resin, film, electrode for energy device, and energy device

Abstract

According to the present invention, a polyamide-imide resin composition contains a polyamide-imide resin, and one or more solvents selected from an ether solvent and an acyclic ester solvent.

Description

Polyamide-imide resin composition, polyamide-imide resin, film, electrode for energy device and energy device

[0001] This disclosure relates to polyamide-imide resin compositions, polyamide-imide resins, films, electrodes for energy devices, and energy devices.

[0002] Polyamide-imide resins are used in a variety of applications, including insulating materials, protective films, nonwoven fabrics, adhesives, and battery electrodes, due to their excellent heat resistance, electrical insulation, chemical resistance, solvent resistance, and strength when made into films.

[0003] As an example of a polyamide-imide resin, Patent Document 1 describes a polyamide-imide resin obtained by copolymerizing poly(acrylonitrile-butadiene) with dimer acid or polyester, which has a glass transition temperature of 120°C or higher, a logarithmic viscosity of 0.1 dl / g or higher, and a tensile modulus of 1,500 MPa or lower.

[0004] Japanese Patent Publication No. 2008-208295

[0005] When polyamide-imide resins are to be used as solutions, organic solvents with excellent solubility for polyamide-imide resins are generally used, specifically N-methyl-2-pyrrolidone, N,N'-dimethylacetamide, and γ-butyrolactone. However, among these, N-methyl-2-pyrrolidone is becoming subject to increasingly stringent regulations from the perspective of environmental protection and safety and health. Furthermore, as the applications of polyamide-imide resins expand, there has been a demand for polyamide-imide resins that can be dissolved in other solvents, such as acyclic ester solvents and ether solvents.

[0006] One of the objectives of this disclosure is to provide a polyamide-imide resin composition containing one or more solvents selected from ether solvents and acyclic ester solvents, a polyamide-imide resin with excellent solvent solubility, a film, an electrode for an energy device, and an energy device.

[0007] This disclosure includes, but is not limited to, the following embodiments. One embodiment relates to a polyamide-imide resin composition comprising a polyamide-imide resin and one or more solvents selected from ether solvents and acyclic ester solvents.

[0008] Another embodiment relates to a polyamide-imide resin comprising structural units derived from at least one selected from the group consisting of tricarboxylic acid anhydrides and their derivatives (A), structural units derived from polyester polyols (B), and at least one selected from the group consisting of polyisocyanate compounds and polyamine compounds (C), wherein the ratio of structural units derived from polyester polyols (B) to the total number of moles of structural units derived from tricarboxylic acid anhydrides or their derivatives (A) and structural units derived from polyester polyols (B) is 40 mol% or more.

[0009] This disclosure makes it possible to provide a polyamide-imide resin composition containing one or more solvents selected from ether solvents and acyclic ester solvents, a polyamide-imide resin with excellent solvent solubility, a film, an electrode for an energy device, and an energy device.

[0010] The embodiments of the present invention will be described in detail below. The present invention is not limited to the embodiments described below.

[0011] In this disclosure, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, the upper or lower limits of numerical ranges described in this disclosure may be replaced with the values ​​shown in the examples. In this disclosure, each component may contain one or more of the corresponding substances unless otherwise specified. In this disclosure, the content of each component in the resin composition means the total amount of the multiple substances present in the resin composition if there are multiple substances corresponding to each component in the resin composition, unless otherwise specified.

[0012] In this disclosure, unless otherwise specified, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) are values ​​obtained by gel permeation chromatography (GPC) under the following conditions and converted using a calibration curve with standard polystyrene.

[0013] [Method for Measuring Molecular Weight] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) were measured by gel permeation chromatography (GPC) under the following conditions and converted using a calibration curve based on standard polystyrene. The calibration curve was approximated by a cubic equation using a set of five standard polystyrene samples ("TSK standard POLYSTYRENE", manufactured by Tosoh Corporation). The GPC conditions are shown below.

[0014] Instrument: High-speed GPC system HLC-8320GPC (manufactured by Tosoh Corporation) Detector: UV-8320 ultraviolet absorption detector (manufactured by Tosoh Corporation) Wavelength: 270 nm Column: Shodex KF-806L + 806L (manufactured by Resonac Corporation) Column size: 8 mm diameter x 300 mm Solvent: DMF / THF = 1 / 1 (liter) + 0.06 M phosphoric acid + 0.06 M lithium bromide Sample concentration: 5 mg / 1 ml Injection volume: 5 μl Flow rate: 1.0 ml / min

[0015] One embodiment of the polyamide-imide resin composition is a polyamide-imide resin composition comprising a polyamide-imide resin and one or more solvents selected from ether solvents and acyclic ester solvents (hereinafter also referred to as "ether / acyclic ester solvent").

[0016] Regarding the ether solvent, one type of ether solvent may be used alone, or two or more types may be used in combination. The ether solvent may be either an acyclic ether or a cyclic ether, and may be an acyclic ether solvent. That the ether solvent is acyclic means that the ether bond is not involved in ring formation, and it does not prevent the inclusion of a ring structure such as an alicyclic structure in the molecular structure. The acyclic ether solvent may contain a ring structure as a partial structure. The number of ether bonds in one molecule of the ether solvent may be 1 or 2 or more. The number of ether bonds in one molecule of the ether solvent may be in the range of 1 to 3, and may be 1. The number of carbon atoms in one molecule of the ether solvent may be in the range of 2 to 20. Specific examples of the ether solvent include, for example, the compounds represented by the following general formula (1).

[0017]

[0018] [In general formula (1), R

[0020] , ２ , R ３ are each independently an alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, or a cyclohexyl group. R ２ is an alkylene group having 1 to 6 carbon atoms. m and n are each independently 0 or 1. When n and m are each 1, the two Rs ２ in the formula may be the same as or different from each other. ]

[0019] In general formula (1), R １ and R ３ are each independently an alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, or a cyclohexyl group. The alkyl group may be linear or may have a branched structure. The alkyl group may be an alkyl group having 1 to 4 carbon atoms, and specifically may be any of a methyl group, an ethyl group, an n-propyl group, and an n-butyl group. R ３ and R ５ are each independently any of a methyl group, an ethyl group, and an n-butyl group. R ３ and R ５ may be the same as or different from each other.

[0020] R ２This is an alkylene group having 1 to 6 carbon atoms. The alkylene group may be linear or have a branched structure. The alkylene group may be an alkylene group having 2 to 4 carbon atoms, or it may be an ethylene group.

[0021] m and n are independently either 0 or 1. Both m and n may be 0, or both may be 1. Examples of compounds in which m and n are 0 include n-dibutyl ether and cyclopentyl methyl ether. Examples of compounds in which m and n are 1 include diethylene glycol dimethyl ether and diethylene glycol diethyl ether.

[0022] Regarding acyclic ester solvents, "acyclic" means that the ester bond does not participate in ring formation, and does not prevent the inclusion of ring structures such as alicyclic structures in the molecular structure. Acyclic ester solvents may contain ring structures as partial structures. Acyclic ester solvents may be used alone or in combination of two or more types. Examples of acyclic ester solvents include aliphatic carboxylic acid ester solvents and aromatic carboxylic acid esters. The number of carbon atoms in one molecule of an acyclic ester solvent may be in the range of 3 to 20, 4 to 12, or 5 to 10. Specific examples of acyclic ester solvents include, for example, compounds represented by the following general formula (2).

[0023]

[0024] [In general formula (2), R ４ R is an alkyl group having 1 to 6 carbon atoms. ５ It is a monovalent organic group.

[0025] R in general formula (2) ４ R is an alkyl group having 1 to 6 carbon atoms. The alkyl group may be linear or have a branched structure. ４ R may be an alkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 3 carbon atoms. Specifically, R ２ This group may be a methyl group, an ethyl group, or an n-propyl group.

[0026] R in general formula (2) ５ This is a monovalent organic group. Examples of monovalent organic groups include aliphatic hydrocarbon groups, structures in which one or more carbon atoms of an aliphatic hydrocarbon group are replaced by oxygen atoms, and aralkyl groups.

[0027] The aliphatic hydrocarbon group may be linear or branched. The number of carbon atoms in the aliphatic hydrocarbon group is not particularly limited, but may be in the range of 2 to 8, 2 to 6, or 2 to 4. Specifically, R ５ R may be any of the following: a methyl group, an ethyl group, an n-propyl group, or an n-butyl group. ５ Examples of compounds in which the group is an aliphatic hydrocarbon group include ethyl acetate, propyl acetate, and butyl butyrate.

[0028] Regarding a structure in which one or more carbon atoms of an aliphatic hydrocarbon group are replaced by oxygen atoms, the structure may be linear or branched. The total number of carbon atoms and oxygen atoms is not particularly limited, but may be in the range of 2 to 8, or 2 to 6. ５ Examples of compounds having this structure include propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate.

[0029] Examples of aralkyl groups include benzyl groups, α-methylbenzyl groups, triphenylmethyl groups, naphthylmethyl groups, etc. ２ Examples of compounds in which the group is an aralkyl group include benzyl acetate.

[0030] The acyclic ester solvent may be propyl acetate or butyl butyrate.

[0031] The solvent may contain at least one selected from the group consisting of butyl acetate, butyl butyrate, n-dibutyl ether, and cyclopentyl methyl ether, and may also contain butyl butyrate.

[0032] The polyamide-imide resin composition may contain solvents other than ether / acyclic ester solvents. The ratio of ether / acyclic ester solvent to the solvent components in the polyamide-imide resin composition may be 70% by mass or more, 90% by mass or more, or 100% by mass. More preferably, the ratio of the total amount of propyl acetate, butyl butyrate, n-dibutyl ether, and cyclopentyl methyl ether to the solvent components in the polyamide-imide resin composition is within these ranges. Even more preferably, the ratio of butyl butyrate to the solvent components in the polyamide-imide resin composition is within these ranges.

[0033] In a polyamide-imide resin composition, the content of the ether / acyclic ester solvent is not particularly limited and can be adjusted as appropriate depending on the application of the polyamide-imide resin composition, the desired performance, etc. For example, the proportion of the ether / acyclic ester solvent in the polyamide-imide resin composition may be 20% by mass or more, 30% by mass or more, 35% by mass or less, or 40% by mass or more. It may also be 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less. The proportion of the ether / acyclic ester solvent in the polyamide-imide resin composition may be in the range of 20 to 80% by mass.

[0034] The specific structure of the polyamide-imide resin contained in the polyamide-imide resin composition is not particularly limited, as long as it is soluble in an ether / acyclic ester solvent. An example of a polyamide-imide resin soluble in an ether / acyclic ester solvent is a polyamide-imide resin containing a polyester structure.

[0035] In polyamide-imide resins, the polyester structure may be introduced in any form. For example, the polyester structure may be introduced by using a polyester polyol as a reaction raw material for the polyamide-imide resin. Polyamide-imide resins are generally produced using tricarboxylic acid anhydride or its derivative and one or more selected from the group consisting of polyisocyanate compounds and polyamine compounds as reaction raw materials. Therefore, the polyamide-imide resin may contain structural units derived from tricarboxylic acid anhydride or its derivative (A), structural units derived from polyester polyol (B), and structural units derived from one or more selected from polyisocyanate compounds and polyamine compounds (C).

[0036] At least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives (hereinafter also referred to as "acid component (A)") is not particularly limited as long as it is a trivalent carboxylic acid having an acid anhydride group that reacts with an isocyanate group or an amino group, including its derivatives. Acid component (A) may be used alone or in combination of two or more. In terms of excellent heat resistance of the resin, acid component (A) may be a compound having an aromatic ring group. Specific examples of acid component (A) include compounds represented by the following general formulas (3) or (4). Acid component (A) may also be trimellitic anhydride.

[0037]

[0038] [In general formula (4), X is a methylene group, a carbonyl group, a sulfonyl group, or an oxygen atom.]

[0039] Polyester polyol (B) may be the result of a condensation reaction between a polyol compound and a polycarboxylic acid compound. Examples of polyol compounds include diol compounds such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol; trifunctional or more polyol compounds such as glycerin, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol; and (poly)oxyalkylene modified products in which (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains are introduced into the molecular structure of these compounds. One type of polyol compound may be used alone, or two or more types may be used in combination.

[0040] Examples of polycarboxylic acid compounds include aliphatic dicarboxylic acid compounds such as oxalic acid, malonic acid, succinic acid, maleic acid (anhydride), fumaric acid, citraconic acid (anhydride), glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid; alicyclic dicarboxylic acids such as tetrahydrophthalic acid (anhydride), hexahydrophthalic acid (anhydride), and 1,4-cyclohexanedicarboxylic acid; and aromatic dicarboxylic acid compounds such as phthalic acid (anhydride), isophthalic acid, and terephthalic acid. A single polycarboxylic acid compound may be used alone, or two or more may be used in combination.

[0041] Among these, polyester diols using a diol compound and a dicarboxylic acid compound are preferred because they exhibit superior solubility in ether / acyclic ester solvents. The dicarboxylic acid compound may also contain an aliphatic dicarboxylic acid compound. The proportion of the aliphatic dicarboxylic acid compound in the dicarboxylic acid compound may be 40 mol% or more, 60 mol% or more, 80 mol% or more, or 100 mol%.

[0042] The molecular weight of polyester polyol (B) is adjusted as appropriate depending on the application of the polyamide-imide resin and the desired performance. However, for superior solubility in ether / acyclic ester solvents, the number average molecular weight (Mn) may be 500 or more, 1,000 or more, or 1,500 or more. It may also be 5,000 or less, 4,000 or less, or 3,000 or less. The number average molecular weight (Mn) of polyester polyol (B) may be in the range of 500 to 5,000.

[0043] At least one (C) selected from the group consisting of polyisocyanate compounds and polyamine compounds (hereinafter also referred to as "polyisocyanate / polyamine (C)") is, for example, an aliphatic diisocyanate compound such as butanediisocyanate, hexamethylenediisocyanate, 2,2,4-trimethylhexamethylenediisocyanate, 2,4,4-trimethylhexamethylenediisocyanate; an aliphatic diamine compound such as hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine;

[0044] Alicyclic diisocyanate compounds such as norbornane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate; alicyclic diamine compounds such as diaminoisophorone, bis(4-aminocyclohexyl)methane, 1,4-diaminotranscyclohexane, and hydrogenated m-xylylenediamine;

[0045] Tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, 4,4'-diisocyanatodiphenylmethane, 4,4'-diisocyanatobiphenyl, 3,3'-diisocyanatobiphenyl, 3,4'-diisocyanatobiphenyl, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, 4,4'-diisocyanato-2,2'-dimethylbiphenyl, 4,4'-diisocyanato-3,3'-diethylbiphenyl, 4,4'-diisocyanato-2,2'-diethylbiphenyl, 4,4'-diisocyanato-3,3'-dimethoxybiphenyl, 4,4'-diisocyanato-2,2'-dimethoxybiphenyl, 1,5-diisocyanatonaphthalene, 2,6-diisocyanatonaphthalene, 4,4'-diisocyanatodiphenyl Examples include aromatic diisocyanate compounds such as nyl ether, 2,2-bis[4-(4'-isocyanatophenoxy)phenyl]propane, and polymethylene polyphenyl polyisocyanate; and aromatic diamine compounds such as 4,4'-diaminodiphenylmethane, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-3,3'-diethylbiphenyl, 4,4'-diamino-2,2'-diethylbiphenyl, 4,4'-diamino-3,3'-dimethoxybiphenyl, 4,4'-diamino-2,2'-dimethoxybiphenyl, 1,5-diaminonaphthalene, and 2,6-diaminonaphthalene.

[0046] The polyisocyanate may be an isocyanurate modified compound, a biuret modified compound, an allophanate modified compound, etc. If necessary to avoid changes over time, a compound in which the isocyanate group has been stabilized with a blocking agent may be used. Examples of blocking agents include alcohols, phenols, oximes, etc., but there are no particular restrictions. Furthermore, one type of polyisocyanate / polyamine (C) may be used alone, or two or more types may be used in combination. In particular, in terms of excellent heat resistance of the resin, the polyisocyanate / polyamine (C) may contain one or more compounds selected from aromatic diisocyanate compounds and aromatic diamine compounds. The proportion of aromatic diisocyanate compounds and aromatic diamine compounds in the polyisocyanate / polyamine (C) may be 80% by mass or more, 90% by mass or more, or 100% by mass.

[0047] The polyamide-imide resin may contain structural units derived from other compounds, in addition to structural units derived from the acid component (A), the polyester polyol (B), and the polyisocyanate / polyamine (C). The total mass ratio of structural units derived from the acid component (A), the polyester polyol (B), and the polyisocyanate / polyamine (C) in the polyamide-imide resin may be 80% by mass or more, 90% by mass or more, or 100% by mass.

[0048] In polyamide-imide resins, the proportions of structural units derived from the acid component (A), the polyester polyol (B), and the polyisocyanate / polyamine (C) are appropriately adjusted according to the application of the polyamide-imide resin, the desired performance, etc. For superior solubility in ether / acyclic ester solvents, it is preferable that the proportion of structural units derived from polyester polyol (B) to the total number of moles of structural units derived from the acid component (A) and the polyester polyol (B) is 40 mol% or more. The upper limit may be 70 mol% or less, 60 mol% or less, or 65 mol% or less. The proportion of structural units derived from polyester polyol (B) to the total number of moles of structural units derived from the acid component (A) and the polyester polyol (B) may be in the range of 40 to 70 mol%.

[0049] Furthermore, the ratio of structural units derived from polyester polyol (B) to the total mass of structural units derived from acid component (A), structural units derived from polyester polyol (B), and structural units derived from polyisocyanate / polyamine (C) may be 40% by mass or more, 50% by mass or more, or 60% by mass or more. It may also be 85% by mass or less, 80% by mass or less, or 75% by mass or less. The ratio of structural units derived from polyester polyol (B) to the total mass of structural units derived from acid component (A), structural units derived from polyester polyol (B), and structural units derived from polyisocyanate / polyamine (C) may be in the range of 40 to 80% by mass.

[0050] There are no particular restrictions on the method for producing polyamide-imide resin, but for example, it can be produced using an acid component (A), a polyester polyol (B), and a polyisocyanate / polyamine (C) as reaction raw materials. The total mass ratio of the acid component (A), polyester polyol (B), and polyisocyanate / polyamine (C) to the total mass of the polyamide-imide resin reaction raw materials may be 80% by mass or more, 90% by mass or more, or 100% by mass.

[0051] The ratio of the total number of moles of isocyanate groups and amino groups contained in the polyisocyanate / polyamine (C) to the total number of moles of carboxyl groups, acid anhydride groups, and hydroxyl groups contained in the acid component (A) and polyester polyol (B) may be in the range of 0.8 to 1.5 moles.

[0052] The reaction order of the acid component (A), polyester polyol (B), and polyisocyanate / polyamine (C) is not particularly limited. For example, they may be reacted together, or the polyester polyol (B) and polyisocyanate / polyamine (C) may be reacted to obtain an intermediate, which may then be reacted with the acid component (A) and, if necessary, with polyisocyanate / polyamine (C). The reaction temperature is not particularly limited, but may be in the range of 80 to 180°C. A catalyst may be used if desired. The reaction may also be carried out in a solvent. The amount of solvent used is not particularly limited, but may be in the range of 100 to 300 parts by mass per 100 parts by mass of the total reactant materials.

[0053] The solvent used in the reaction may be an ether / acyclic ester solvent, another solvent, or a mixture thereof. Examples of other solvents include polar solvents such as N-methyl-2-pyrrolidone, N,N'-dimethylformamide, γ-butyrolactone, N,N'-dimethylpropylene urea [1,3-dimethyl-3,4,5,6-tetrahydropyridimine-2(1H)-one], dimethyl sulfoxide, and sulfolane; aromatic hydrocarbon solvents such as xylene and toluene; and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone. These may be used individually or in combination of two or more.

[0054] As an example of a method for synthesizing polyamide-imide resin, we will describe a method in which a polyester polyol (B) is reacted with a polyisocyanate / polyamine (C) to obtain an intermediate, and this intermediate is then reacted with an acid component (A) and, if necessary, with polyisocyanate / polyamine (C) again. The reaction ratio of polyester polyol (B) and polyisocyanate / polyamine (C) when reacting them to obtain the intermediate is not particularly limited, but it may be in the range where the terminal end of the intermediate is an isocyanate group or an amino group. For example, the total number of moles of isocyanate groups and amino groups of polyisocyanate / polyamine (C) per mole of hydroxyl groups in polyester polyol may be in the range of 1.6 to 2 moles.

[0055] In this reaction, the high solubility of polyester polyol (B) in ether / acyclic ester solvent allows for an increase in the non-volatile content of the reaction mixture. For example, the non-volatile content of the reaction mixture may be 40% by mass or more, 50% by mass or more, or 60% by mass or more.

[0056] The reaction ratio when the obtained intermediate is reacted with the acid component (A) and, if necessary, with the polyisocyanate / polyamine (C) is not particularly limited, but for example, the total number of moles of isocyanate groups and amino groups relative to the total of 1 mole of carboxyl groups and acid anhydride groups in the acid component (A) may be in the range of 0.8 to 1.2 moles. Since the non-volatile content of the reaction mixture can be increased during the synthesis of the intermediate, the non-volatile content of the reaction mixture can also be increased in the subsequent main reaction. For example, the non-volatile content of the reaction mixture may be 20 to 80% by mass, 30 to 70% by mass, or 40 to 60% by mass.

[0057] In the resulting polyamide-imide resin composition, the polyester structure derived from polyester polyol (B) enhances the solubility of the polyamide-imide resin in ether / acyclic ester solvents. Furthermore, since the non-volatile content in the reaction mixture can be increased, the synthesis reaction of the polyamide-imide resin proceeds more efficiently, and a higher degree of polymerization can be expected. To obtain such effects, it is desirable that the hydrocarbon structure of the ether / acyclic ester solvent and the hydrocarbon structure of the polyester structure portion of the polyamide-imide resin are at least partially common. For example, when using butyl butyrate, n-propylene butyl acetate, or dibutyl ether as solvents, the polyamide-imide resin composition can be made more concentrated by having a structure derived from an aliphatic dicarboxylic acid in polyester polyol (B), preferably a structure derived from an aliphatic dicarboxylic acid having 3 to 6 carbon atoms, specifically a structure derived from adipic acid. In particular, when using butyl butyrate as a solvent, a highly concentrated polyamide-imide resin composition can be obtained and the generation of precipitates can be suppressed by having a structure derived from adipic acid in polyester polyol (B).

[0058] When using other solvents, a polyamide-imide resin composition containing the ether / acyclic ester solvent can be obtained by methods such as solvent substitution after synthesis of the polyamide-imide resin, or by removing the solvent to obtain a solid polyamide-imide resin and then redissolving it in the ether / acyclic ester solvent, as needed.

[0059] The molecular weight of the polyamide-imide resin is adjusted as appropriate depending on the application of the polyamide-imide resin, the desired performance, etc. For example, the number average molecular weight (Mn) may be 3,000 or more, 5,000 or more, 8,000 or more, 15,000 or more, or 20,000 or more. It may also be 100,000 or less, 80,000 or less, 50,000 or less, or 30,000 or less. The number average molecular weight (Mn) of the polyamide-imide resin may be in the range of 3,000 to 100,000.

[0060] The weight-average molecular weight (Mw) of the polyamide-imide resin may be 3,000 or more, 5,000 or more, 8,000 or more, 15,000 or more, or 20,000 or more. It may also be 300,000 or less, 200,000 or less, 100,000 or less, or 50,000 or less. The weight-average molecular weight (Mw) of the polyamide-imide resin may be in the range of 3,000 to 300,000.

[0061] The degree of dispersion (Mw / Mn) of the polyamide-imide resin may be 3 or less, 2.8 or less, or 2.5 or less. Its lower limit is not particularly limited, but may be 1 or more, 1.1 or more, or 1.2 or more. The degree of dispersion of the polyamide-imide resin may be in the range of 1 to 3.

[0062] The polyamide-imide resin composition may contain other components in addition to the polyamide-imide resin and the ether / acyclic ester solvent. The other components are appropriately selected depending on the application of the polyamide-imide resin composition, the desired performance, etc. Examples of other components include other resin components such as polyamide, polyethersulfone, acrylic polymer, epoxy compound, isocyanate compound, and melamine compound, as well as fillers, defoamers, preservatives, and surfactants.

[0063] The polyamide-imide resin of one embodiment comprises structural units derived from at least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives, structural units derived from polyester polyol (B), and structural units derived from at least one (C) selected from the group consisting of polyisocyanate compounds and polyamine compounds, wherein the ratio of structural units derived from polyester polyol (B) to the total number of moles of structural units derived from at least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives and polyester polyol (structural units derived from B) is 40 mol% or more. The polyamide-imide resin is characterized by particularly excellent solubility in ether / acyclic ester solvents. Further details of the polyamide-imide resin are as described above.

[0064] The applications of the polyamide-imide resin composition and polyamide-imide resin disclosed herein are not particularly limited and can be used in a wide variety of applications. Some specific examples include applications in insulating materials, protective films, nonwoven fabrics, adhesives, and battery electrodes, taking advantage of the excellent heat resistance, electrical insulation, chemical resistance, solvent resistance, and strength of the polyamide-imide resin when made into a film. Furthermore, because the polyamide resin composition components of this disclosure contain ether / acyclic ester solvents, and the polyamide-imide resin exhibits excellent solubility in ether / acyclic ester solvents, it can be preferably used in applications where conventional solvent solutions such as N-methyl-2-pyrrolidone, which have been widely used as solvents for polyamide-imide resins, were difficult to use due to safety, hygiene, or other reasons.

[0065] [Film] The film of one embodiment is a film obtained using a polyamide-imide resin composition. The film of another embodiment is a film containing polyamide-imide resin. The method for producing the film is not particularly limited, but as an example, it can be obtained by coating a substrate such as a glass plate with a polyamide-imide resin composition, drying it, and then heating it. The drying temperature may be in the range of 50 to 100°C, for example. The heating temperature may be in the range of 230 to 350°C, for example. The film thickness is set appropriately depending on the application, but may be in the range of 5 to 1,000 μm, for example.

[0066] [Electrodes for Energy Devices] One embodiment of an energy device electrode is an energy device electrode obtained using a polyamide-imide resin composition. Another embodiment of an energy device electrode is an energy device electrode containing a polyamide-imide resin. The polyamide-imide resin can be used in any way in an energy device electrode, but one example is that it can be used as a binder resin for the active material.

[0067] [Energy Device] The energy device of one embodiment is an energy device that includes the electrodes for the energy device described above. More specifically, it has a positive electrode and a negative electrode, and at least one of the positive electrode and the negative electrode includes the electrodes for the energy device of one embodiment. Examples of energy devices include non-aqueous electrolyte secondary batteries such as lithium-ion secondary batteries, all-solid-state batteries, capacitors, and the like.

[0068] [Non-aqueous electrolyte secondary battery] A non-aqueous electrolyte secondary battery comprises, for example, an electrode group including a positive electrode, a negative electrode, and a separator, and a battery casing that houses the electrode group. The battery casing is filled with an electrolyte. A non-aqueous electrolyte secondary battery may be a so-called laminated type battery, or a battery of a shape other than laminated type (coin type, cylindrical type, stacked type, etc.).

[0069] The positive electrode and the negative electrode may each have a current collector and an electrode composite layer formed on at least a portion of the surface of the current collector, and the electrode composite layer may be a coating film obtained using a polyamide-imide resin composition containing an active material, or a coating film containing an active material and a polyamide-imide resin.

[0070] Examples of materials for current collectors include copper, stainless steel, nickel, aluminum, titanium, calcined carbon, conductive polymers, conductive glass, and aluminum-cadmium alloys. The surface of the current collector may be treated with carbon, nickel, titanium, silver, etc., from the viewpoint of improving adhesion, conductivity, and reduction resistance. Examples of current collector shapes include plates and films.

[0071] Examples of positive electrode active materials include nickel cobalt manganese oxide (NCM), lithium cobalt dioxide (LCO), nickel cobalt aluminum oxide (NCA), and lithium manganese oxide (LMO).

[0072] Examples of negative electrode active materials include carbon-based active materials and silicon-based active materials. One type of active material may be used alone, or two or more types may be used in combination.

[0073] The carbon-based active material may be a carbon material, such as amorphous carbon material, natural graphite, a composite carbon material obtained by forming an amorphous carbon material film on natural graphite, or artificial graphite (graphite obtained by calcining resin raw materials such as epoxy resin or phenolic resin, or pitch-based raw materials obtained from petroleum, coal, etc.). Preferably, the carbon-based active material contains one or more selected from natural graphite and artificial graphite.

[0074] Silicon-based active materials contain at least silicon, and include, for example, silicon-containing alloys, silicon-containing oxides, silicon-containing nitrides, or silicon-containing carbides. Examples of silicon-containing alloys include alloys containing silicon and at least one element selected from the group consisting of tin, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, and chromium. Specific examples of silicon-containing oxides include SiO, SiO ２ , , LiSiO and other silicon-containing nitrides are examples of Si３ N ４ Si ２ N ２ Examples of silicon-containing carbides include O, SiC, etc.

[0075] The active material content in the polyamide-imide resin composition may be 80% by mass or more, 90% by mass or more, or 95% by mass or more, relative to the total mass of components other than the solvent. It may also be 99% by mass or less, or 95% by mass or less. The active material content may be in the range of 80 to 99% by mass relative to the total mass of components other than the solvent.

[0076] The polyamide-imide resin composition may further contain resin materials known as electrode binders, such as polyolefin resins and acrylic resins, conductive materials, and other additives.

[0077] Examples of conductive materials include carbon black such as acetylene black and Ketjenblack, graphite, graphene, and carbon nanotubes. While the active material can be selected from materials capable of functioning as an active material, such as materials with a structure capable of absorbing and releasing electrolytes such as lithium ions, the conductive material can be selected from materials that cannot function as an active material, such as materials without a structure capable of absorbing and releasing electrolytes such as lithium ions. When the polyamide-imide resin composition contains a conductive material, the content of the conductive material may be 0.01% by mass or more, 0.1% by mass or more, or 1% by mass or more, relative to the total mass of the components other than the solvent. It may also be 50% by mass or less, 30% by mass or less, or 15% by mass or less. The content of the conductive material may be in the range of 0.01 to 50% by mass relative to the total mass of the components other than the solvent.

[0078] When the current collector is in the form of a plate or film, the electrode comprises at least the current collector and an electrode mixture layer formed on one or both surfaces of the current collector. The electrode mixture layer can be formed, for example, by the following method: First, an amide-imide resin composition containing an active material is prepared and applied to at least one surface of the current collector to form a coating. Then, the solvent contained in the coating is evaporated. After the solvent has evaporated, the coating can be compression molded to form the electrode mixture layer. Examples of application methods include the doctor blade method, dipping method, spray method, and transfer roll method. An example of a compression molding method is the roll press method. Compression molding can be performed while heating the coating. Compression molding may be performed at room temperature or under heated conditions, and then the coating may be heated. The heating temperature may be, for example, in the range of 200 to 300°C.

[0079] Examples of separators include, but are not limited to, polyethylene nonwoven fabric, polypropylene nonwoven fabric, polyamide nonwoven fabric, and nonwoven fabrics thereof that have been treated to be hydrophilic. The battery casing may be, for example, a container formed from a laminate film. Examples of laminate films include laminated films in which a resin film such as polyethylene terephthalate (PET) film, a metal foil such as aluminum, copper, or stainless steel, and a sealant layer such as polypropylene are laminated in that order.

[0080] The electrolyte solution contains, for example, an electrolyte and a non-aqueous solvent. The electrolyte may be a lithium salt. An example of a lithium salt is LiPF4. ６ LiBF ４ LiClO ４ LiB(C) ６ H ５ ) ４ LiCH ３ SO ３ CF ３ SO ２ OLi, LiN(SO ２ F) ２ (Li[FSI], lithium bisfluorosulfonyliimide), LiN(SO ２ CF ３ ) ２(Li[TFSI], lithium bistrifluoromethanesulfonyliimide), and LiN(SO ２ CF ２ CF ３ ) ２ The non-aqueous solvent may be at least one selected from the group consisting of the following. Examples of non-aqueous solvents include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, acetonitrile, 1,2-dimethoxyethane, dimethoxymethane, tetrahydrofuran, dioxolane, methylene chloride, methyl acetate, etc. The electrolyte may contain additives such as vinylene carbonate.

[0081] [All-Solid-State Battery] An all-solid-state battery comprises, for example, an electrode body in which a sheet-shaped positive electrode, a sheet-shaped negative electrode, and a separator placed between the positive and negative electrodes are stacked. The electrode body may contain one or more layers of positive and negative electrodes. An example of a positive electrode is one comprising a positive electrode current collector and positive electrode active material layers formed on both sides thereof, while an example of a negative electrode is one comprising a negative electrode current collector and negative electrode active material layers formed on both sides thereof.

[0082] Examples of positive electrode current collectors include metal foils made of aluminum, nickel, titanium, stainless steel, etc. The positive electrode active material layer may include, for example, a positive electrode active material, a solid electrolyte, and optionally a conductive agent and a binder. The positive electrode active material may have a portion of its particle surface coated with the solid electrolyte. The positive electrode active material layer may be a coating film obtained using a polyamide-imide resin composition containing the positive electrode active material and a solid electrolyte, or a coating film containing the positive electrode active material, a solid electrolyte, and a polyamide-imide resin.

[0083] The positive electrode active material is, for example, LiCoO ２ LiNiO ２ LiNi ｘ Co ｙ Mn （１－ｘ－ｙ） O ２ (Here, a composite oxide with a layered structure such as 0 < x < 1, 0 < y < 1, 0 < x + y < 1; Li ２ NiMn ３ O ８ LiMn ２ O４ , Li １＋ｘ Mn ２－ｙ M ｙ O ４ (where M is absent or one or more metal elements selected from Al, Mg, Co, Fe, Ni, Zn, 0 ≦ x < 1, 0 ≦ y < 2), etc., composite oxides having a spinel structure; LiFePO ４ and other composite compounds having an olivine structure, etc.

[0084] The solid electrolyte contained in the positive electrode active material layer includes, for example, oxide-based solid electrolytes and sulfide-based solid electrolytes. Examples of oxide-based solid electrolytes include those having a NASICON structure, those having a garnet-type structure, and those having a perovskite-type structure. Specific examples of oxide-based solid electrolytes include, for example, Li ３ BO ３ , LiBO ２ , Li ２ CO ３ , LiAlO ２ , Li ４ SiO ４ , Li ２ SiO ３ , Li ３ PO ４ , Li ２ SO ４ , Li ２ TiO ３ , Li<000007​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​２ O-SiO ２ system, Li ２ O-B ２ O ３ system, Li ２ O-B ２ O ３ -ZnO-based glass or glass ceramics may be used.

[0085] A specific example of a sulfide-based solid electrolyte is, for example, Li ２ S-SiS ２ system, Li ２ S-P ２ S ３ system, Li ２ S-P ２ S ５ system, Li ２ S-GeS ２ system, Li ２ S-B ２ S ３ system, Li ３ PO ４ -P ２ S ５ system, Li ４ SiO ４ -Li ２ S-SiS ２ Glass or glass ceramics such as LiBr-Li ２ S-P ２ S ５ LiI-Li ２ S-P ２ S ５ , LiBr-LiI-Li ２ S-P ２ S ５ Li ２ Li is composed of S and lithium halide. ２ Examples include solid solutions based on sulfur.

[0086] Examples of conductive materials include carbon materials such as acetylene black, graphite, and carbon nanotubes. In addition to polyamide-imide resin, binders such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and rubber binders such as styrene-butadiene rubber (SBR) may also be used in combination.

[0087] Examples of negative electrode current collectors include metal foils such as copper or copper-based alloys. The negative electrode active material layer may include, for example, a negative electrode active material, a solid electrolyte, and optionally a conductive agent or binder. The negative electrode active material layer may be a coating film obtained using a polyamide-imide resin composition containing the negative electrode active material and a solid electrolyte, or a coating film containing the negative electrode active material, a solid electrolyte, and a polyamide-imide resin.

[0088] The negative electrode active material is a carbon-based active material such as graphite, mesocarbon microbeads, acetylene black, Ketjenblack, and other carbon blacks; Si, SiO ａ Silicon oxide, SiC, is represented here as 0.05 < a < 1.95. ｂ Silicon carbide, SiN, represented by (0 < b < 1) ｃ Si-based active materials such as silicon nitride represented by (0 < c < 4 / 3), and alloy materials consisting of silicon and elements other than silicon (e.g., Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc.); tin, SnO ｄ Tin oxide and tin dioxide (SnO) represented by (0 < d < 2) ２ ) and other tin oxides, tin nitrides, tin-containing alloys such as Ni-Sn alloys, Mg-Sn alloys, Fe-Sn alloys, Cu-Sn alloys, Ti-Sn alloys, SnSiO ３ Ni ２ Sn ４ Mg ２ Examples include tin compounds such as Sn, and Sn-based active materials such as solid solutions thereof.

[0089] The solid electrolyte contained in the negative electrode active material layer is similar to that contained in the positive electrode active material layer. The conductive agent and binder resin that the negative electrode active material layer may contain are similar to those that the positive electrode active material layer may contain.

[0090] The separator may be a layer containing solid electrolyte particles of the same type as the solid electrolyte contained in the positive and negative electrode active material layers, and a porous substrate. Examples of the porous substrate include those formed from thermoplastic resins, nonwoven fabric substrates made of glass fibers, etc. Examples of the thermoplastic resins include polyolefin resins such as polyethylene and polypropylene, polyamide resins, polyamide-imide resins, thermoplastic polyimide resins, thermoplastic polyester resins, etc.

[0091] Examples of embodiments are listed below. The disclosure is not limited to the following embodiments. <1> A polyamide-imide resin composition comprising a polyamide-imide resin and one or more solvents selected from ether solvents and acyclic ester solvents.

[0092] <2> The polyamide-imide resin composition according to <1>, wherein the polyamide-imide resin contains a polyester structure.

[0093] <3> The polyamide-imide resin composition according to <1> or <2>, wherein the polyamide-imide resin comprises structural units derived from at least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives, structural units derived from polyester polyol (B), and structural units derived from at least one (C) selected from the group consisting of polyisocyanate compounds and polyamine compounds, and the ratio of structural units derived from polyester polyol (B) to the total number of moles of structural units derived from at least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives and structural units derived from polyester polyol (B) is 40 mol% or more.

[0094] <4> The polyamide-imide resin composition according to any one of <1> to <3>, wherein the solvent comprises one or more selected from the group consisting of butyl acetate, butyl butyrate, n-dibutyl ether, and cyclopentyl methyl ether.

[0095] <5> The polyamide-imide resin composition according to any one of <1> to <3>, wherein the solvent contains butyl butyrate.

[0096] A film obtained using the polyamide-imide resin composition described in any one of <6>, <1>, to <5>.

[0097] An electrode for an energy device obtained using the polyamide-imide resin composition described in any one of <7>, <1>, to <5>.

[0098] An energy device including electrodes for energy devices as described in <8> and <7>.

[0099] <9> A polyamide-imide resin comprising structural units derived from at least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives, structural units derived from polyester polyol (B), and structural units derived from at least one (C) selected from the group consisting of polyisocyanate compounds and polyamine compounds, wherein the ratio of structural units derived from polyester polyol (B) to the total number of moles of structural units derived from at least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives and structural units derived from polyester polyol (B) is 40 mol% or more.

[0100] A film containing the polyamide-imide resin described in <10> and <9>.

[0101] An electrode for an energy device containing the polyamide-imide resin described in <11> and <9>.

[0102] An energy device including electrodes for energy devices as described in <12> and <11>.

[0103] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0104] [Method for Measuring Molecular Weight] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) were measured by gel permeation chromatography (GPC) under the following conditions and converted using a calibration curve based on standard polystyrene. The calibration curve was approximated by a cubic equation using a set of five standard polystyrene samples ("TSK standard POLYSTYRENE", manufactured by Tosoh Corporation). The GPC conditions are shown below.

[0105] Instrument: High-speed GPC system HLC-8320GPC (manufactured by Tosoh Corporation) Detector: UV-8320 ultraviolet absorption detector (manufactured by Tosoh Corporation) Wavelength: 270 nm Column: Shodex KF-806L + 806L (manufactured by Resonac Corporation) Column size: 8 mm diameter x 300 mm Solvent: DMF / THF = 1 / 1 (liter) + 0.06 M phosphoric acid + 0.06 M lithium bromide Sample concentration: 5 mg / 1 ml Injection volume: 5 μl Flow rate: 1.0 ml / min

[0106] [Example 1: Production of Polyamide-Imide Resin (1)] 13.9 g (0.08 mol) of toylene-2,4-diisocyanate, 79.4 g (0.04 mol) of polyol (*1), and 62.2 g of butyl butyrate were charged into a flask equipped with a thermometer, stirrer, and condenser. The mixture was heated to 120°C while stirring under a stream of dry nitrogen and reacted for 1 hour to obtain a butyl butyrate solution of the composition containing the urethane prepolymer (60% by mass of non-volatile content). Subsequently, 111 g of butyl butyrate was added to dilute the solution to 40% of non-volatile content, and then 11.5 g (0.06 mol) of trimellitic anhydride and 10.6 g (0.06 mol) of toylene-2,4-diisocyanate were added at 40°C. The solution was heated to 145°C and reacted for 5 hours, after which the reaction was stopped to obtain a butyl butyrate solution of polyamide-imide resin (1) (40% by mass of non-volatile content).

[0107] (*1) Polyol: Amorphous polyester polyol with adipic acid, propylene glycol, and neopentyl glycol as the main reaction components (2 hydroxyl groups per molecule, number average molecular weight (Mn) 2,000)

[0108] [Comparative Example 1: Production of Polyamide-Imide Resin (1')] 7.00 g (0.04 mol) of toylene-2,4-diisocyanate, 40.0 g (0.02 mol) of polyol (*1), and 31.3 g of butyl butyrate were charged into a flask equipped with a thermometer, stirrer, and condenser. The mixture was heated to 120°C while stirring under a stream of dry nitrogen and reacted for 1 hour to obtain a butyl butyrate solution of the composition containing the urethane prepolymer (60% by mass of non-volatile content). Subsequently, 138.8 g of butyl butyrate was added to dilute the solution to 40% of non-volatile content, and then 15.4 g (0.08 mol) of trimellitic anhydride and 10.6 g (0.06 mol) of toylene-2,4-diisocyanate were added at 40°C. The solution was heated to 145°C and reacted for 5 hours, after which the reaction was stopped to obtain a butyl butyrate solution of polyamide-imide resin (1') (40% by mass of non-volatile content).

[0109] [Confirmation of solubility in ether / acyclic ester solvents] 40% by mass butyl butyrate solutions of the polyamide-imide resins obtained in Example 1 and Comparative Example 1 were stored at room temperature, and the presence or absence of precipitation of the polyamide-imide resins was observed. No precipitation occurred in the polyamide-imide resin of Example 1 even after storage for one day. On the other hand, precipitation occurred in the polyamide-imide resin (1') of Comparative Example 1 after one day.

[0110] The disclosures of this application are related to the subject matter described in Japanese Patent Application No. 2025-009106, filed on 22 January 2025, the disclosures of which are incorporated herein by reference.

Claims

1. A polyamide-imide resin composition comprising a polyamide-imide resin and one or more solvents selected from ether solvents and acyclic ester solvents.

2. The polyamide-imide resin composition according to claim 1, wherein the polyamide-imide resin contains a polyester structure.

3. The polyamide-imide resin composition according to claim 1, wherein the polyamide-imide resin comprises structural units derived from at least one selected from the group consisting of tricarboxylic acid anhydrides and their derivatives (A), structural units derived from polyester polyols (B), and structural units derived from at least one selected from the group consisting of polyisocyanate compounds and polyamine compounds (C), and the ratio of structural units derived from polyester polyols (B) to the total number of moles of structural units derived from at least one selected from the group consisting of tricarboxylic acid anhydrides and their derivatives (A) and structural units derived from polyester polyols (B) is 40 mol% or more.

4. The polyamide-imide resin composition according to claim 1, wherein the solvent comprises at least one selected from the group consisting of propyl acetate, butyl butyrate, n-dibutyl ether, and cyclopentyl methyl ether.

5. The polyamide-imide resin composition according to claim 1, wherein the solvent comprises butyl butyrate.

6. A film obtained using the polyamide-imide resin composition according to any one of claims 1 to 5.

7. An electrode for an energy device obtained using the polyamide-imide resin composition according to any one of claims 1 to 5.

8. An energy device comprising an electrode for an energy device as described in claim 7.

9. A polyamide-imide resin comprising structural units derived from at least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives, structural units derived from polyester polyol (B), and structural units derived from at least one (C) selected from the group consisting of polyisocyanate compounds and polyamine compounds, wherein the ratio of structural units derived from polyester polyol (B) to the total number of moles of structural units derived from at least one (A) selected from the group consisting of tricarboxylic acid anhydrides and their derivatives and structural units derived from polyester polyol (B) is 40 mol% or more.

10. A film comprising the polyamide-imide resin according to claim 9.

11. An electrode for an energy device comprising the polyamide-imide resin according to claim 9.

12. An energy device comprising an electrode for an energy device as described in claim 11.

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