Adhesive composition, cured product, adhesive sheet, member for fuel cell, and method for producing urethane urea resin

Abstract

To provide a resin suitable for an adhesive for a solid polymer fuel cell (excellent in heat resistance and wet heat resistance) and a method for producing the same, and further to provide a useful adhesive well adhering to PPS and a solid polymer electrolyte membrane and satisfying wet heat resistant adhesive force and heat resistant adhesive force.SOLUTION: At least one of the compound (A), the polyisocyanate compound (B), and the amine compound (C) has an alicyclic structure, the polyol compound (A) contains a diol compound (a1) having a carboxyl group, a total content of components having an alicyclic structure in a total of 100% by mass of components constituting the urethane urea resin is 5.0 to 40.0% by mass, and an acid number of the urethane urea resin is 5 to 30mgKOH / g, the urethane urea resin according to claim 1, wherein the urethane urea resin has a urea-bond concentration of 0.20 to 1.1 00mmol / g SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a urethane urea resin, an adhesive composition, a cured product, an adhesive sheet, a fuel cell member, and a method for producing a urethane urea resin. [Background technology]

[0002] Energy and environmental issues have created a demand for clean, highly efficient power generation devices. Fuel cells are a clean power generation system that, in principle, produces water as a product of electrode reactions and has almost no adverse impact on the global environment. In particular, polymer electrolyte fuel cells are highly anticipated for practical use because they can be started at relatively low temperatures and can be made smaller and have higher output.

[0003] Generally, a solid polymer electrolyte fuel cell has a solid polymer electrolyte membrane made of a polymer ion exchange membrane, and uses a membrane electrode assembly (MEA) as a component, in which an anode electrode is disposed on one side of the solid polymer electrolyte membrane and a cathode electrode is disposed on the other side. In recent years, as in Patent Documents 1 to 3, configurations have been proposed that employ a resin frame member on the periphery in order to reduce the amount of expensive solid polymer electrolyte membrane used and to support the solid polymer electrolyte membrane, which has low membrane strength. In configurations using the resin frame member, if an adhesive is used, it is necessary to bond both the resin frame member and the solid polymer electrolyte membrane. Furthermore, because hydrogen and oxygen generate heat and produce water, the adhesive used to bond the gasket member must be able to withstand use in high-temperature, high-humidity environments.

[0004] Examples of resins used to construct the resin frame include polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET). Among these, PPS boasts excellent heat resistance, flame retardancy, rigidity, chemical resistance, hot water resistance, and electrical insulation, making it superior in long-term durability to PET and PEN. Therefore, it is expected to improve the long-term durability of fuel cells. However, PPS has poor wettability and adhesive properties, making it difficult to bond PPS to a solid polymer electrolyte membrane. Therefore, there is a need for a useful adhesive that can bond PPS to a solid polymer electrolyte membrane well (initial adhesion) and also has excellent adhesive strength even after moist heat treatment and high-temperature treatment (moisture-resistant adhesion and heat-resistant adhesion). The properties of the adhesive depend on the physical properties of the resin used. To develop an adhesive that can achieve the above-mentioned performance, a resin that does not deteriorate under high-temperature and moist heat conditions and exhibits good adhesive properties when used as an adhesive is required. However, such a resin has not yet been developed. [Prior art documents] [Patent documents]

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-066766 Patent Document 2: Japanese Patent Application Laid-Open No. 2017-162640 Patent Document 3: JP 2021-180135 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to provide a resin suitable for use as an adhesive in polymer electrolyte fuel cells (excellent in heat resistance and moist heat resistance) and a method for producing the same, as well as to provide a useful adhesive that adheres well to PPS and a solid polymer electrolyte membrane and also has satisfactory moist heat resistant adhesive strength and heat resistant adhesive strength. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by the following embodiments, and have thus completed the present invention.

[0008] An embodiment of the present invention relates to a urethane urea resin containing a polyol compound (A), a polyisocyanate compound (B), and an amine compound (C) as structural units, wherein at least one of the polyol compound (A), the polyisocyanate compound (B), and the amine compound (C) has an alicyclic structure; the polyol compound (A) contains a diol compound (a1) having a carboxy group; the total content of the components having an alicyclic structure is 5.0 to 40.0 mass% relative to 100 mass% of the total components constituting the urethane urea resin; the acid value of the urethane urea resin is 5 to 30 mgKOH / g; and the urea bond concentration in the urethane urea resin is 0.20 to 1.00 mmol / g.

[0009] Another embodiment of the present invention relates to the urethane urea resin, wherein the polyol compound (A) further comprises at least one of a dimer diol (a2) and a polycarbonate polyol (a3); the polyisocyanate compound (B) comprises a polyisocyanate (b1) having an alicyclic structure; and the amine compound (C) comprises a diamine (c1) having an alicyclic structure.

[0010] Another embodiment of the present invention relates to a method for producing the urethane urea resin in a mixed solvent containing two solvents: a solvent (S1) having a hydrogen bond term Δh of Hansen solubility parameters of 0 or more but less than 10, and a solvent (S2) having a Δh of 10 to 25, wherein the proportion of solvent (S2) in 100 mass% of the mixed solvent is 10 to 40 mass%.

[0011] Another embodiment of the present invention relates to an adhesive composition comprising the urethane urea resin and a curing agent, wherein the curing agent contains at least one compound selected from the group consisting of epoxy compounds, carbodiimide compounds, oxazoline compounds, and aziridine compounds, and wherein the ratio (Y / X) of the carboxy group (X) in the urethane urea resin to the functional group (Y) in the curing agent is 1.0 / 1.0 to 5.0 / 1.0.

[0012] Another embodiment of the present invention relates to a cured product obtained by curing the adhesive composition.

[0013] Another embodiment of the present invention relates to an adhesive sheet having an adhesive layer made of the adhesive composition and a substrate.

[0014] Another embodiment of the present invention relates to a fuel cell member made of the adhesive sheet. [Effects of the Invention]

[0015] The present invention provides a resin suitable for use as an adhesive in polymer electrolyte fuel cells (excellent in heat resistance and moist heat resistance) and a method for producing the same, and further provides a useful adhesive that adheres well to PPS and a solid polymer electrolyte membrane and also has satisfactory moist heat resistance and heat resistance. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be described in detail below. In the following description, the "diol compound (a1) having a carboxy group," the "polyisocyanate (b1) having an alicyclic structure," and the "diamine (c1) having an alicyclic structure" may be abbreviated as "diol (a1)," "polyisocyanate (b1)," and "diamine (c1)," respectively. In this specification, a numerical range specified using "to" is intended to include the numerical values ​​before and after "to" as the range's lower and upper limits.

[0017] The urethane urea resin of the present invention contains a polyol compound (A), a polyisocyanate compound (B), and an amine compound (C) as constituent units. Each component constituting the urethane urea resin of the present invention will be described below.

[0018] <Polyol compound (A)> The polyol compound (A) contains a diol compound (a1) having a carboxy group. The diol (a1) can be used alone or in combination of two or more. By including the diol (a1), a crosslinking group can be introduced into the resin, resulting in excellent heat resistance and moist heat resistance.

[0019] Examples of the diol (a1) include dihydroxyfumaric acid, dihydroxymaleic acid, dimethylolacetic acid, glyceric acid, dimethylolpropionic acid, dimethylolpropionic acid, 2,3-dihydroxy-2-methylpropanoic acid, dimethylolbutanoic acid, 2,2-dimethylolbutanoic acid, 2,3-dihydroxybutanoic acid, 3-deoxytetronic acid, 3,4-dihydroxybutanoic acid, 2,4-dihydroxy-3,3-dimethylbutanoic acid, 2,3-dihydroxy-2-methylbutanoic acid, 2,3-dihydroxy-2-ethylbutanoic acid, 2,3-dihydroxy-2-isopropylbutanoic acid, and 2,3-dihydroxy-2-butyl aliphatic dioxycarboxylic acids such as butanoic acid, vanadium acid, tartaric acid, dimethylol valeric acid, mevalonic acid, dimethylol caproic acid, dimethylol enanthic acid, dimethylol caprylic acid, dimethylol bellargonic acid, dimethylol capric acid, dimethylol lauric acid, dimethylol myristic acid, 2,2-bis(hydroxymethyl)pentadecanoic acid, dimethylol palmitic acid, dimethylol margaric acid, dimethylol stearic acid, dimethylol oleic acid, dimethylol linoleic acid, dimethylol linolenic acid, dimethylol arachodonic acid, dimethylol docosahexaenoic acid, and dimethylol eicosapentaenoic acid; 2,3-Dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,6-dihydroxy-4-methylbenzoic acid, 2,4-dihydroxy-6-methylbenzoic acid, 3,5-dihydroxy-4-methylbenzoic acid, 2,4-dihydroxy-3,6-dimethylbenzoic acid, 2,3-dihydroxy-4-methoxybenzoic acid, 3,4-dihydroxy-5-methoxybenzoic acid, 2,4-di(hydroxymethyl)benzoic acid, 3 ,4-Di(hydroxymethyl)benzoic acid, 4-bromo-3,5-dihydroxybenzoic acid, 5-bromo-2,4-dihydroxybenzoic acid, 3-chloro-2,6-dihydroxybenzoic acid, 5-chloro-2,4-dihydroxybenzoic acid, hydroxy(4-hydroxy-3-methoxyphenyl)acetic acid, D,L-3,4-dihydroxymandelic acid, 2,5-dihydroxyphenylacetic acid, 3,4-dihydroxyphenylacetic acid, 3,4-(methylenedioxy)phenylacetic acid, 3-(3,4-dihydroxyphenyl)propanoic acid, 3-(2,4-dihydroxyphenyl)propanoic acid Bis(p-hydroxyphenyl)acrylic acid, 3-(3,4-dihydroxyphenyl)acrylic acid, 4,4'-bis(p-hydroxyphenyl)pentanoic acid, 3-(3,4-methylenedioxyphenyl)propionic acid, 2,2-bis(hydroxymethyl)butyric acid, 2,4-dihydroxycinnamic acid, 2,5-dihydroxycinnamic acid, cinnamyl-3,4-dihydroxy-α-cyanocinnamic acid, 2-bromo-4,5-methylenedioxycinnamic acid, 3,4-methylenedioxycinnamic acid, 4,5-methylenedioxy-2-nitrocinnamic acid, 2,6-dihydroxyisonicotinic acid, DL-methyl- -3,4-Dihydroxymandelic acid, 1,4-dihydroxy-2-naphthalenecarboxylic acid, 3,5-dihydroxy-2-naphthalenecarboxylic acid, 3,7-dihydroxy-2-naphthalenecarboxylic acid, 4,8-dihydroxyquinoline-2-carboxylic acid (also known as xanthurenic acid), 3-(3,4-dihydroxyphenyl)propionic acid, 2,4-dihydroxypyrimidine-5-carboxylic acid, 2,6-dihydroxypyridine-4-carboxylic acid (also known as citrazinic acid), 2,4-dihydroxythiazole-5-acetic acid, 2-(1-thienyl)ethyl-3,Examples of suitable dihydroxycarboxylic acids include aromatic ring- or heterocyclic ring-containing dihydroxycarboxylic acids such as 4-dihydroxybenzylidene cyanoacetic acid, 6-estradiol dipropionate, 2,5-dihydroxy-1,4-benzenediacetic acid, and (2R,3R)-2,3-dihydroxy-3-(phenylcarbamoyl)propionic acid. From the viewpoint of solvent solubility, dimethylolpropionic acid and dimethylolbutanoic acid are preferred.

[0020] The polyol compound (A) may contain, in addition to the diol (a1), at least one of a dimer diol (a2) and a polycarbonate polyol (a3).

[0021] Dimer diol (a2) is synthesized by hydrogenating dimer acid, a dimer of unsaturated fatty acids, and is obtained as a mixture of geometric isomers of dimer diols having branched or alicyclic structures. The dimer acid is obtained by thermally polymerizing 18-carbon carboxylic acids, such as unsaturated fatty acids such as linoleic acid, oleic acid, and linolenic acid, and drying or semi-drying fatty acids obtained from tall oil, cottonseed oil, soybean oil, etc., using a known method, followed by distillation and purification. The main component is a 36-carbon dicarboxylic acid. Dimer diol can be synthesized from dimer acid by known hydrogenation methods. Specifically, it can be obtained by catalytic reduction according to standard methods using a hydrogenation catalyst such as Raney nickel, nickel-diatomaceous earth, or an inorganic refractory material (e.g., alumina, silica, etc.) supported with a Group 8 element such as platinum. Commercially available dimer diols for use in the present invention include, for example, Pripol 2033 manufactured by Croda.

[0022] Examples of the polycarbonate polyol (a3) ​​include those obtained by reacting a low molecular weight polyol with a carbonate compound.

[0023] Examples of the low molecular weight polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, octanediol, nonanediol, dipropylene glycol, diethylene glycol, triethylene glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, polyoxyethylene difunctional low molecular weight polyols such as ethylene glycol (addition mole number 10 or less), polyoxypropylene glycol (addition mole number 10 or less), cyclohexanediol, cyclohexanedimethanol, tricyclodecane dimethanol, cyclopentadiene dimethanol, dimer diol, bisphenol A, N,N-bis(2-hydroxypropyl)aniline, dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid, dihydroxypropionic acid, and dihydroxybenzoic acid; Trimethylolethane, trimethylolpropane, 1,1,1-trimethylolbutane, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,6-butanetriol, trimethylolbutene, trimethylolpentene, trimethylolhexene, trimethylolheptene, trimethyloloctene, trimethylolnonene, trimethyloldecene, trimethylolundecene, trimethyloldodecene, trimethyloltridecene, trimethylolpentadecene, trimethylolhexadecene, trimetrolheptadecene, trimethylol Trimethylol octadecene, 1,1,1-trimethylol-2-methyl-hexane, 1,1,1-trimethylol-3-methyl-hexane, 1,1,1-trimethylol-2-ethyl-hexane, 1,1,1-trimethylol-3-ethyl-hexane, trimethylol hexene, 1,2,3-octanetriol, 1,3,7-octanetriol, 3,7-dimethyl-1,2,3-octanetriol, 1,1,1-, 1,1,1-trimethylol decane, 1,2,10-decanetriol, 1,1,1-trimethylol isoheptadecane, 1,1,1-trimethylol hexene ... Trimethylol-sec-butane, 1,1,1-trimethylol-tert-pentane, 1,1,1-trimethylol-tert-nonane, 1,1,1-trimethylol-tert-tridecane, 1,1,1-trimethylol-tert-heptadecane, 1,1,1-trimethylol-2-methyl-hexane, 1,1,1-trimethylol-3-methyl-hexane, 1,1,1-trimethylol-2-ethyl-hexane, 1,1,1-trimethylol-3-ethyl-hexane, 1,1,1-trimethylolisoheptadecane, 1,2,3,4-butanetetramethylol Examples of such low molecular weight polyols include tri- or higher functional polyols such as ethanol, pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, diglycerin, triglycerin, polyglycerin, ditrimethylolethane, ditrimethylolpropane, tris(2-hydroxyethyl)isocyanurate, benzene-1,3,5-triol, benzene-1,2,3-triol, stilbene-3,4',5-triol, sucrose, inositol, sorbitan, sorbitol, mannitol, saccharose, cellulose, and xylitol.

[0024] The carbonate compound may be a dialkyl carbonate such as dimethyl carbonate or diethyl carbonate; Examples of alkylene carbonates include alkylene carbonates such as ethylene carbonate; Diaryl carbonates include, for example, diaryl carbonates such as diphenyl carbonate.

[0025] From the viewpoint of improving heat resistance and moist heat resistance, the polyol compound (A) preferably contains, in addition to the diol (a1), at least one of a dimer diol (a2) and a polycarbonate polyol (a3). The polycarbonate polyol (a3) ​​is more preferably a polycarbonate polyol having an alicyclic structure. The polycarbonate polyol having an alicyclic structure is not particularly limited as long as it has an alicyclic structure having 6 or more carbon atoms in the molecule, and for example, those described in Japanese Patent No. 5303846 can be used.

[0026] The polyol compound (A) may contain a polyol other than the carboxyl group-containing diol (a1), dimer diol (a2), and polycarbonate polyol (a3) ​​for the purpose of controlling adhesiveness and durability, etc. In addition to the low-molecular-weight polyols described in the explanation of the polycarbonate polyol (a3), polyether polyols, polyester polyols, polyolefin polyols, vegetable oil-based polyols other than dimer diols, and mixtures thereof, which are generally known as polyols constituting polyurethane resins, can be used.

[0027] Examples of polyether polyols include polymers or copolymers of methylene oxide, ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc., and glycols such as polyethylene glycol, polypropylene glycol, poly(ethylene / propylene) glycol, and polytetramethylene glycol; Condensates of hexanediol, methylhexanediol, heptanediol, octanediol or mixtures thereof; Examples include polyols obtained by adding an alkylene oxide such as methylene oxide, ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, or polyoxytetramethylene oxide to a compound having two or more active hydrogen groups.

[0028] Examples of polyester polyols include polyester polyols obtained by condensation reaction of the above-mentioned low-molecular-weight polyols with a dibasic acid component. Examples of dibasic acid components include aliphatic or aromatic dibasic acids such as terephthalic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, hydrogenated dimer acid, phthalic anhydride, isophthalic acid, trimellitic acid, glutaric acid, pimelic acid, suberic acid, and sebacic acid, as well as anhydrides thereof. Furthermore, polyester polyols obtained by ring-opening polymerization of cyclic ester compounds of lactones such as ε-caprolactone, poly(β-methyl-γ-valerolactone), and polyvalerolactone may also be used.

[0029] Examples of polyolefin polyols include hydroxyl group-containing polybutadiene, hydrogenated hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydrogenated hydroxyl group-containing polyisoprene, hydroxyl group-containing chlorinated polypropylene, and hydroxyl group-containing chlorinated polyethylene.

[0030] Examples of vegetable oil-based polyols other than dimer diol include polyols made from plant-derived castor oil or soybean oil.

[0031] <Polyisocyanate compound (B)> The polyisocyanate compound (B) is not particularly limited as long as it contains two or more isocyanate groups in one molecule. In the present invention, the polyisocyanate compound (B) is roughly classified into polyisocyanates (b1) having an alicyclic structure and polyisocyanates not having an alicyclic structure. The polyisocyanate compound (B) can be used alone or in combination of two or more kinds.

[0032] Examples of the polyisocyanate (b1) include isophorone diisocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (4,4'-methylenebis(cyclohexyl isocyanate, HMDI), 1,4-bis(isocyanatomethyl)cyclohexane, hydrogenated xylylene diisocyanate, dimer acid diisocyanate, and norbornene diisocyanate. Of these, from the viewpoint of moist heat resistance, IPDI and HMDI are preferred as the polyisocyanate (b1), and IPDI is more preferred.

[0033] Examples of polyisocyanates that do not have an alicyclic structure include aliphatic polyisocyanates that do not have an alicyclic structure, such as butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate; Examples of the aromatic polyisocyanates include those not having an alicyclic structure, such as 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-benzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, and xylylene diisocyanate.

[0034] The polyisocyanate compound (B) preferably contains a polyisocyanate (b1) having an alicyclic structure, which improves the wet heat resistance.

[0035] <Amine Compound (C)> The amine compound (C) can be appropriately selected from known compounds. It preferably contains a diamine (c1) having an alicyclic structure, and may contain amines other than the diamine (c1). Each of these can be used alone or in combination of two or more. By containing the diamine (c1), the moist heat resistance is improved.

[0036] Examples of the diamine (c1) having an alicyclic structure include alicyclic diamines such as isophoronediamine (IPDA), norbornanediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1,4-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), piperazine, and dimer diamine.

[0037] Dimer diamine is an alicyclic diamine compound obtained by substituting the two terminal carboxyl groups (—COOH) of a dimer acid with an aminomethyl group (—CH—NH) or an amino group (—NH). Dimer acid is a known compound obtained by dimerizing unsaturated fatty acids (preferably those having 11 to 22 carbon atoms, particularly preferably those having 18 carbon atoms), and its industrial production process is largely standardized in the industry. Dimer acids primarily composed of 36-carbon dimer acids obtained by dimerizing 18-carbon unsaturated fatty acids, such as oleic acid and linoleic acid, are particularly useful because they are inexpensive and readily available. Depending on the production method, degree of purification, and other factors, dimer acids may contain arbitrary amounts of monomer acid, trimer acid, other polymerized fatty acids, and the like. Although double bonds remain after the polymerization reaction (dimerization reaction) of unsaturated fatty acids, in the present invention, hydrogenated products obtained by further hydrogenation to reduce the degree of unsaturation are also included in the term dimer acid. Commercially available products of dimer diamine (c1) include, for example, "Priamine 1071," "Priamine 1073," "Priamine 1074," and "Priamine 1075" manufactured by Croda Japan Co., Ltd., and "Versamin 551" and "Versamin 552" manufactured by Cognis Japan Co., Ltd.

[0038] Of the above, from the viewpoint of moist heat resistance, IPDA, dimer diamine, 1,4-bis(aminomethyl)cyclohexane, and 4,4'-methylenebis(cyclohexylamine) are preferred as diamine (c1), and IPDA and dimer diamine are more preferred.

[0039] Other examples of the amine compound include aliphatic diamines having no alicyclic structure, aromatic diamines, diaminopolysiloxanes, polyoxyalkylene polyamines, aliphatic monoamines, and aromatic monoamines.

[0040] Examples of aliphatic diamines not having an alicyclic structure include ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,9-nonanediamine, 1,12-dodecamethylenediamine, metaxylenediamine, 2-(2-aminoethylamino)ethanol, N-(2-hydroxyethyl)-1,3-propanediamine, (2-hydroxyethylpropylene)diamine, N,N'-bis(2-hydroxyethyl)ethylenediamine, (di-2-hydroxyethylpropylene)diamine, (2-hydroxypropylethylene)diamine, and (di-2-hydroxypropylethylene)diamine.

[0041] Aromatic diamines include 1,4-diaminobenzene, 1,3-diaminobenzene, 1,2-diaminobenzene, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,3-diaminonaphthalene, 2,6-diaminotoluene, 2,4-diaminotoluene, 3,4-diaminotoluene, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 4,4'-diamino-1,2-diphenylethane, 3, Examples of such an amino acid include 3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,3'-diaminodiphenyl sulfone, bisanilinefluorene, 4,4'-isopropylidenebis(2-aminophenol), 4,4'-(hexafluoroisopropylidene)bis(2-aminophenol), and 5,5'-methylenebis(2-aminobenzoic acid).

[0042] Examples of diaminopolysiloxanes include α,ω-bis(2-aminoethyl)polydimethylsiloxane, α,ω-bis(3-aminopropyl)polydimethylsiloxane, α,ω-bis(4-aminobutyl)polydimethylsiloxane, α,ω-bis(5-aminopentyl)polydimethylsiloxane, α,ω-bis[3-(2-aminophenyl)propyl]polydimethylsiloxane, α,ω-bis[3-(4-aminophenyl)propyl]polydimethylsiloxane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,3-bis(4-aminobutyl)tetramethyldisiloxane, etc. Commercially available diaminopolysiloxanes include KF-8010, X-22-161A, and X-22-161B (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0043] Examples of polyoxyalkylene polyamines include polyoxypropylene diamine, trimethylolpropane poly(oxypropylene) triamine, glyceryl poly(oxypropylene) triamine, polyoxyethylene diamine, trimethylolpropane poly(oxyethylene) triamine, glyceryl poly(oxyethylene) triamine, etc. Commercially available polyoxyalkylene polyamines include JEFFAMINE D-230, JEFFAMINE D-400, JEFFAMINE D-2000, and JEFFAMINE D-4000 (all manufactured by HUNTSMAN).

[0044] Examples of the aliphatic monoamine include n-butylamine, di-n-butylamine, n-propylamine, n-pentylamine, n-hexylamine, n-octylamine, cyclohexylamine, N-methylcyclohexylamine, monoethanolamine, and diethanolamine.

[0045] Examples of aromatic monoamines include aniline, 1-naphthylamine, 2-naphthylamine, 1-aminoanthracene, 2-aminoanthracene, 9-aminoanthracene, 9-aminophenanthracene, 2-aminobiphenyl, 3-aminobiphenyl, 4-aminobiphenyl, 2-aminophenol, 3-aminophenol, 4-hydroxybenzylamine, 2-hydroxybenzylamine, 4-aminophenol, 2-mercaptoaniline, 3-mercaptoaniline, and 4-mercaptoaniline.

[0046] <Urethane urea resin> In the urethane urea resin of the present invention, at least one of the polyol compound (A), polyisocyanate compound (B), and amine compound (C) has an alicyclic structure, the polyol compound (A) contains a diol compound (a1) having a carboxy group, and the content of the component having an alicyclic structure is 5.0 to 40.0 mass% relative to 100 mass% of the total components constituting the urethane urea resin. When the total content of the component having an alicyclic structure in the urethane urea resin is 5.0 to 40.0 mass%, good moist heat resistance and heat resistance can be obtained.

[0047] The alicyclic content indicates the mass percentage of the moiety (alicyclic hydrocarbon residue) obtained by removing two hydrogen atoms from an alicyclic hydrocarbon. For example, if the alicyclic structure is a cyclohexane ring, the moiety (cyclohexane residue) obtained by removing two hydrogen atoms from cyclohexane is used. The content of components having an alicyclic structure in a urethane urea resin indicates the mass percentage of alicyclic hydrocarbon residues present in the polyurethane resin. Specifically, if a urethane urea resin is composed of 20 parts of a compound with an alicyclic content of 49.5%, 60 parts of a compound with an alicyclic content of 0%, and 20 parts of a compound with an alicyclic content of 46.4%, the total mass percentage of components having an alicyclic structure in the urethane urea resin is calculated as 49.5 x 0.2 + 0 x 0.6 + 46.4 x 0.2 = 19.2 mass%.

[0048] The total content of components having an alicyclic structure in the urethane urea resin is more preferably 10.0 to 30.0% by mass, and even more preferably 10.0 to 25.0% by mass.

[0049] The urethane urea resin of the present invention is characterized by having an acid value of 5 to 30 mgKOH / g and a urea bond concentration in the urethane urea resin of 0.20 to 1.00 mmol / g. When the acid value is 5 to 30 mgKOH / g, good heat resistance is obtained, and when the urea bond concentration in the urethane urea resin is 0.20 to 1.00 mmol / g, adhesion to substrates is improved.

[0050] The acid value of the urethane urea resin is preferably 5 to 15 mgKOH / g. The method for measuring the acid value will be described in detail in the Examples.

[0051] The urea bond concentration in the urethane urea resin is preferably 0.20 to 0.80 mmol / g, and more preferably 0.40 to 0.80 mmol / g.

[0052] The urea binding concentration is a value expressed by the following formula: When a prepolymer having a terminal isocyanate group is synthesized under the condition of (NCO molar equivalents / OH molar equivalents) > 1 and then chain-extended with polyamine to give a polyurethane resin having an amino group at the end, the polyurethane resin is represented by the following formula (1). Equation (1) Urea bond concentration (mmol / g) = [Total number of moles of isocyanate groups (mmol) - Total number of moles of hydroxyl groups (mmol)] / Total solid content (g) When a prepolymer having a terminal isocyanate group is synthesized under the above condition of (NCO molar equivalents / OH molar equivalents) > 1 and then chain-extended with polyamine to give a polyurethane resin having an isocyanate group at its terminal, the polyurethane resin is represented by the following formula (2). Equation (2) Urea bond concentration (mmol / g) = (total number of amino group moles (mmol)) / total solid content (g) The total number of moles of amino groups herein refers to the total number of moles of amino groups contained in the amine compound used to form urea bonds by reacting with a prepolymer having a terminal isocyanate group.

[0053] The weight-average molecular weight of the urethane urea resin is preferably 90,000 to 190,000, and more preferably 100,000 to 150,000. When the weight-average molecular weight is 90,000 to 190,000, good moist heat resistance and heat resistance can be obtained. The weight-average molecular weight is a weight-average molecular weight calculated in terms of polystyrene, determined by gel permeation chromatography (GPC).

[0054] <Method for producing urethane urea resin> The urethane urea resin of the present invention can be produced by a general synthesis method. A general synthesis method for a urethane urea resin is described below. First, a polyol compound (A) and a polyisocyanate compound (B) are subjected to a urethane reaction together with a reaction solvent in a reaction vessel. The polyisocyanate compound (B) is blended so that the total number of moles of isocyanate groups contained in the polyisocyanate compound (B) is 1.1 to 2 equivalents to the total number of moles of hydroxyl groups in the entire polyol compound (A), thereby synthesizing a urethane prepolymer having an isocyanate group at the polymer terminal. The reaction is preferably carried out at 60 to 120°C until all hydroxyl groups are consumed. The urethane prepolymer is then subjected to a urea-forming reaction with an amine compound (C). The amount of the amine compound (C) is adjusted so that the total number of moles of amino groups in the amine compound (C) is 0.9 to 1 equivalent to the total number of moles of isocyanate groups in the urethane prepolymer, and the reaction is preferably carried out at 40 to 100°C until all of the amino groups are consumed.

[0055] A reaction catalyst can be used as needed to promote the urethanization reaction and the urea-forming reaction. Examples of the reaction catalyst include metal catalysts such as tin, bismuth, zinc, aluminum, and titanium, and amine catalysts. Tin catalysts are the most common metal catalysts, and examples of usable catalysts include dibutyltin dilaurate, dioctyltin dilaurate, and octic tin. Examples of usable amine catalysts include triethylamine and N,N-dimethylbenzylamine.

[0056] In the synthesis of the urethane prepolymer, it is preferable not to use a solvent having active hydrogen, such as an alcohol-based solvent. Preferred solvents include, for example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Aromatic hydrocarbons such as benzene, toluene, xylene, and tetramethylbenzene; glycol ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, and triethylene glycol diethyl ether; Esters such as ethyl acetate, butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, dialkyl glutarate, dialkyl succinate, and dialkyl adipate; cyclic esters such as γ-butyrolactone; It is preferable to use petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

[0057] On the other hand, in the urea reaction, which is the reaction between the urethane prepolymer and the amine compound (C), alcoholic solvents can also be used in addition to the above solvents. This is because the reaction between an isocyanate group and an amino group is much faster than the reaction between an isocyanate group and a hydroxyl group, and therefore does not hinder the urea reaction. Examples of alcoholic solvents that can be used include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutanol, t-butanol, n-pentanol, n-hexanol, n-octanol, 2-ethylhexyl alcohol, and 1-methoxy-2-propanol.

[0058] The Hansen solubility parameter (HSP) of the solvent in the present invention will be explained below. The Hansen solubility parameter is a solubility parameter introduced by Hildebrand, which is divided into three components: a dispersion term δd, a polar term δp, and a hydrogen bonding term δh, and is expressed in a three-dimensional space. In the present invention, the hydrogen bonding term δh is used. These three components, the dispersion term δd, the polar term δp, and the hydrogen bond term δh, have been extensively explored by Hansen and his successors, and are described in detail in POLYMER Handbook (fourth edition), VII-698~711. Furthermore, the values ​​of Hansen solubility parameters for many solvents have been investigated and are described, for example, in Industrial Solvents Handbook by Wesley L. Archer.

[0059] In producing the urethane urea resin of the present invention, the reaction is preferably carried out in a mixed solvent containing two solvents: a solvent (S1) having a hydrogen bond term Δh of Hansen solubility parameters of 0 or more and less than 10, and a solvent (S2) having a Δh of 10 to 25, and the proportion of solvent (S2) in 100 mass% of the mixed solvent is preferably 10 to 40 mass%. By containing the above two solvents and keeping the proportions within the above ranges, the urethane urea resin of the present invention can be produced stably.

[0060] <Adhesive composition> The adhesive composition of the present invention contains the urethane urea resin (main agent) of the present invention and a curing agent.

[0061] <Curing agent> The curing agent is not particularly limited as long as it reacts with the urethane urea resin of the present invention to produce a cured product, but is preferably a compound having multiple functional groups capable of reacting with the carboxyl groups in the urethane urea resin of the present invention. Examples include polyisocyanate compounds, epoxy compounds, carbodiimide compounds, oxazoline compounds, aziridine compounds, and metal chelate compounds. It is preferable to contain at least one selected from the group consisting of epoxy compounds, carbodiimide compounds, oxazoline compounds, and aziridine compounds, and from the viewpoint of adhesiveness, an epoxy compound is more preferable. One type of curing agent may be used alone, or two or more types may be used in combination.

[0062] The epoxy compound is not particularly limited as long as it has an epoxy group in the molecule. However, as the epoxy compound, one having an average of two or more epoxy groups in one molecule is preferably used. For example, epoxy compounds such as glycidyl ether type epoxy resin, glycidyl amine type epoxy resin, glycidyl ester type epoxy resin, or cyclic aliphatic (alicyclic) epoxy resin can be used.

[0063] Examples of glycidyl ether type epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AD ​​type epoxy resins, cresol novolac type epoxy resins, phenol novolac type epoxy resins, α-naphthol novolac type epoxy resins, bisphenol A type novolac type epoxy resins, dicyclopentadiene type epoxy resins, tetrabromobisphenol A type epoxy resins, brominated phenol novolac type epoxy resins, tris(glycidyloxyphenyl)methane, and tetrakis(glycidyloxyphenyl)ethane.

[0064] Examples of the glycidylamine type epoxy resin include tetraglycidyldiaminodiphenylmethane, triglycidyl paraaminophenol, triglycidyl meta-aminophenol, and tetraglycidyl meta-xylylenediamine.

[0065] Examples of glycidyl ester type epoxy resins include diglycidyl phthalate, diglycidyl hexahydrophthalate, and diglycidyl tetrahydrophthalate.

[0066] Examples of cyclic aliphatic (alicyclic) epoxy resins include epoxycyclohexylmethyl-epoxycyclohexanecarboxylate and bis(epoxycyclohexyl)adipate.

[0067] As the epoxy compound, one of these compounds can be used alone or two or more can be used in combination. From the viewpoint of durability, it is preferable to use bisphenol A type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, tris(glycidyloxyphenyl)methane, or tetrakis(glycidyloxyphenyl)ethane.

[0068] The carbodiimide compound is not particularly limited as long as it has two or more carbodiimide groups in the molecule. Examples of carbodiimide compounds include Carbodilite V-01, V-03, V-05, V-07, and V-09 (Nisshinbo Chemical Inc.), and cyclic carbodiimide (Teijin Limited). From the viewpoint of heat resistance, compounds having an average of three or more carbodiimide groups in one molecule are preferred.

[0069] As the oxazoline compound, a compound having two or more oxazoline groups in the molecule is preferably used. Specific examples thereof include 2'-methylenebis(2-oxazoline), 2,2'-ethenebis(2-oxazoline), 2,2'-ethenebis(4-methyl-2-oxazoline), 2,2'-propenebis(2-oxazoline), 2,2'-tetramethylenebis(2-oxazoline), 2,2'-hexamethylenebis(2-oxazoline), 2,2'-octamethylenebis(2-oxazoline), 2,2'-p-phenylenebis(2-oxazoline), 2,2'-p-phenylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylenebis(4-methyl-2-oxazoline), and 2,2'-p-phenylenebis(4-phenyl-2-oxazoline). Alternatively, it may be a copolymer of a vinyl monomer such as 2-isopropenyl-2-oxazoline or 2-isopropenyl-4,4-dimethyl-2-oxazoline with another monomer copolymerizable with the vinyl monomer. Examples of such oxazoline group-containing copolymers include the Epocross series manufactured by Nippon Shokubai Co., Ltd.

[0070] Examples of the aziridine compound include trimethylolpropane tris[3-(aziridin-1-yl)propionate], N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxite), tris-2,4,6-(1-aziridinyl)-1,3,5-triazine, and 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane.

[0071] From the viewpoint of adhesiveness, the ratio (Y / X) of the carboxyl group (X) in the urethane urea resin to the functional group (Y) in the curing agent is preferably 1.0 / 1.0 to 5.0 / 1.0, and more preferably 1.0 / 1.0 to 3.0 / 1.0.

[0072] <Other ingredients> The adhesive composition of the present invention may contain other components such as known additives, such as plasticizers, dispersants, thickeners, antifoaming agents, and leveling agents.

[0073] ≪Cured product≫ The cured product of the present invention refers to a product obtained by curing the above adhesive composition.

[0074] The curing method is not particularly limited, but for example, the composition can be cured by drying the solvent using known drying equipment and then heating. The temperature is preferably 40°C to 170°C, more preferably 60°C to 150°C. The higher the curing temperature, the shorter the curing time, but the curing temperature can be adjusted as desired from the perspective of the heat resistance of the substrate. When curing at 80°C, the curing time is preferably 3 to 7 days. When curing at 150°C, the curing time is preferably 30 minutes to 2 hours.

[0075] <Adhesive sheet> The adhesive sheet of the present invention has an adhesive layer made of the above adhesive composition and a substrate. The adhesive layer may be uncured or cured.

[0076] The method for producing the adhesive sheet is not particularly limited. For example, the adhesive sheet can be coated onto the substrate using a known method such as gravure coater coating, die coater coating, comber coater coating, lip coater coating, slit coater coating, roll coater coating, spray coating, spin coater coating, or electrostatic coating.

[0077] The substrate is not particularly limited as long as it is a resin that can be used to form a resin frame member, and examples thereof include PPS, PPA (polyphthalamide), PEN, PES (polyethersulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride), silicone resin, fluororesin, m-PPE (modified polyphenylene ether resin), PET, PBT (polybutylene terephthalate), and modified polyolefin, with PET, PEN, and PPS being preferred.

[0078] <Fuel cell components> The adhesive sheet of the present invention adheres well to PPS and solid polymer electrolyte membranes and has excellent resistance to moist heat and heat, making it suitable for use as a fuel cell component. The fuel cell component of the present invention refers to a component manufactured using the adhesive sheet of the present invention. Specifically, the component is a resin frame component used to support an MEA. The component is either an adhesive sheet of the present invention applied to an electrically insulating and airtight plastic film such as PPS or PEN, or a sheet obtained by curing the adhesive sheet. The MEA is bonded and fixed to the adhesive sheet by heat lamination, heat pressing, heat curing, or other processes, either alone or in combination. [Example]

[0079] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass". The blend amounts in the table are in parts by mass, and values ​​other than the solvent are calculated as non-volatile content. Note that blank spaces in the table indicate that no blend was made. The weight average molecular weight (Mw) and acid value of the urethane urea resin were measured by the following methods.

[0080] [Weight average molecular weight (Mw)] The weight average molecular weight (Mw) is a polystyrene-equivalent value determined by GPC (gel permeation chromatography) measurement under the following conditions: Apparatus: Shodex GPC System-21 (Showa Denko K.K.) Column: A column consisting of one Shodex KF-802 (Showa Denko K.K.), one Shodex KF-803L (Showa Denko K.K.), and one Shodex KF-805L (Showa Denko K.K.) connected in series. Solvent: tetrahydrofuran Flow rate: 1.0mL / min Temperature: 40℃ Sample concentration: 0.2% Sample injection volume: 100 μL

[0081] [Acid value] Approximately 0.5 g of sample dried under reduced pressure at 100°C was precisely weighed into a stoppered Erlenmeyer flask and dissolved in 100 ml of tetrahydrofuran. Phenolphthalein test solution was added as an indicator and the mixture was left to stand for 30 seconds. The solution was then titrated with 0.1 N alcoholic potassium hydroxide solution until it turned a pale pink color. The acid value was calculated using the following formula. The acid value was the value for the resin in its dry state (unit: mgKOH / g). Acid value (mgKOH / g) = {(5.611 x a x F) / S} / (non-volatile content / 100) Where S: sample amount (g) a: Consumption of 0.1N alcoholic potassium hydroxide solution (ml) F: Potency of 0.1N alcoholic potassium hydroxide solution

[0082] The abbreviations used in this specification are as follows: [Polyol compound (A)] [Carboxylic acid-containing diol compound (a1)] DMBA: Dimethylolbutanoic acid DMPA: Dimethylolpropionic acid [Dimer diol (a2)] P-2033: Dimer diol manufactured by Croda Japan Co., Ltd., product name "PRIPOL (registered trademark) 2033" [Polycarbonate polyol (a3)] UM-90(1 / 3): Polycarbonate diol manufactured by UBE Corporation, product name "ETERNACOLL (registered trademark) UM-90(1 / 3)" UM-90(3 / 1): Polycarbonate diol manufactured by UBE Corporation, product name "ETERNACOLL (registered trademark) UM-90(3 / 1)" UC-100: Polycarbonate diol manufactured by UBE Corporation, product name "ETERNACOLL (registered trademark) UC-100" CD210: Polycarbonate diol, "PLACCEL (registered trademark) CD210" manufactured by Daicel Corporation T-5651: Polycarbonate diol manufactured by Asahi Kasei Corporation, product name "DURANOL (registered trademark) T5651" [Other polyols] CHDM: 1,4-cyclohexanedimethanol

[0083] [Polyisocyanate compound (B)] [Polyisocyanate having an alicyclic structure (b1)] IPDI: Isophorone diisocyanate HMDI: 4,4'-dicyclohexylmethane diisocyanate [Other polyisocyanates] HDI: Hexamethylene diisocyanate

[0084] [Amine compound (C)] IPDA: Isophoronediamine P-1075: Dimer diamine, product name "PRIAMINE (registered trademark) 2033" manufactured by Croda Japan Co., Ltd. CHDA: 1,4-bis(aminomethyl)cyclohexane MBCA: 4,4'-methylenebis(cyclohexylamine) [Other amine compounds] D400: Polyether diamine, trade name "JEFFAMINE (registered trademark) D-400" DBA: Di-n-butylamine

[0085] [Solvents with a hydrogen bonding term δh of Hansen's solubility parameter of 0 or more and less than 10 (S1)] TOL: Toluene MEK: Methyl ethyl ketone PGMAc: Propylene glycol monomethyl ether acetate [Solvents with a hydrogen bond term δh of Hansen's solubility parameter of 10-25 (S2)] IPA: Isopropyl alcohol PM: Propylene glycol monomethyl ether

[0086] [Hardening agent] G-1: Epoxy compound manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 200 g / eq, product name "jER (registered trademark) 1031S" G-2: Epoxy compound manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 187 g / eq, product name "jER (registered trademark) 828" G-3: Epoxy compound manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 174 g / eq, product name "jER (registered trademark) 152" G-4: Epoxy compound manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 94 g / eq, product name "jER (registered trademark) 630" G-5: Polycarbodiimide compound manufactured by Nisshinbo Chemical Inc., carbodiimide equivalent weight 216 g / eq, product name "Carbodilite (registered trademark) V-03" G-6: Polycarbodiimide compound manufactured by Nisshinbo Chemical Inc., carbodiimide equivalent weight 260 g / eq, product name "Carbodilite (registered trademark) V-05" G-7: 2,2'-(1,3-phenylene)bis(2-oxazoline) G-8: Polyfunctional aziridine compound, 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate], trade name "ChemiTite (registered trademark) PZ-33" manufactured by Nippon Shokubai Co., Ltd.

[0087] [Example 1] Urethane urea resin (D-1) solution A reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping device, and nitrogen inlet tube was charged with 4.0 parts of DMBA as a diol compound (a1) having a carboxy group, 100.0 parts of UM-90 (1 / 3) as a polycarbonate polyol (a3), 40.4 parts of IPDI as a polyisocyanate (b1) having an alicyclic structure, and 77.8 parts of TOL as a solvent, and the mixture was reacted for 8 hours at 80°C under a nitrogen atmosphere. 98.8 parts of TOL was added to the mixture to obtain a solution of a urethane prepolymer having an isocyanate group at its terminal. Next, while keeping the obtained prepolymer solution at 70°C, a solution containing 6.8 parts of IPDA as a diamine (c1) having an alicyclic structure, 0.33 parts of DBA as another amine compound, 45.5 parts of IPA as a solvent, and 232.7 parts of TOL was added dropwise over 2 hours. After the addition was completed, the reaction was continued for another 8 hours at 70°C, yielding a urethane urea resin (D-1) solution with an acid value of 10 mgKOH / g, a weight-average molecular weight of 130,000, and a solids content of 25%.

[0088] [Examples 2 to 25, Comparative Examples 1 to 6] Urethane urea resin (D-2 to 25, H-1 to 6) solutions The same procedure as in Example 1 was carried out except that the blending compositions were changed as shown in Tables 1 to 3, to obtain urethane urea resin (D-2 to 25) solutions and comparative resins (H-1 to 6).

[0089] Comparative Example 7 A reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping device, and nitrogen inlet tube was charged with 4.7 parts of DMBA as a diol compound (a1) having a carboxy group, 100.0 parts of UM-90 (1 / 3) as a polycarbonate polyol (a3), 40.4 parts of IPDI as a polyisocyanate (b1) having an alicyclic structure, and 77.8 parts of TOL as a solvent, and the mixture was reacted for 8 hours at 80°C under a nitrogen atmosphere. 98.8 parts of TOL was added to the mixture to obtain a solution of a urethane prepolymer having an isocyanate group at its terminal. Next, while keeping the obtained prepolymer solution at 70°C, a solution containing 6.8 parts of IPDA as a diamine (c1) having an alicyclic structure, 0.3 parts of DBA as another amine compound, 51.0 parts of TOL as a solvent, and 227.1 parts of IPA was added dropwise over 2 hours. After the dropwise addition, the reaction was continued for another 8 hours at 70°C, but precipitation occurred and the desired resin could not be produced. [Comparative Example 8] A reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping device, and nitrogen inlet tube was charged with 4.7 parts of DMBA as a diol compound (a1) having a carboxy group, 100.0 parts of P-2033 as a dimer diol (a2), 62.5 parts of IPDI as a polyisocyanate (b1) having an alicyclic structure, and 90.0 parts of TOL as a solvent, and the mixture was reacted for 8 hours at 80 ° C. under a nitrogen atmosphere. 114.3 parts of TOL was added to obtain a solution of a urethane prepolymer having an isocyanate group at the end. Next, while keeping the obtained prepolymer solution at 70°C, a solution containing 10.5 parts of IPDA as a diamine (c1) having an alicyclic structure, 0.5 parts of DBA as another amine compound, and 330.2 parts of TOL as a solvent was added dropwise over 2 hours. After the dropwise addition, the reaction was continued for another 8 hours at 70°C, but precipitation occurred and the desired resin could not be produced.

[0090] Tables 1 to 3 show details of the obtained urethane urea resins of the present invention (D-1 to 25) and comparative resins (H-1 to 6).

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3]

[0094] <Evaluation of urethane urea resin> The urethane urea resins of the present invention (D-1 to 25) and the comparative resins (H-1 to 6) were evaluated by the following methods, and the results are shown in Tables 1 to 3.

[0095] [Heat resistance] The resulting urethane urea resin was coated onto an aluminum plate to a dry coating thickness of 50 μm, and then dried in an electric oven at 80°C for 3 minutes to obtain a urethane urea resin-coated plate. The coated plate was then heated in an electric oven at 120°C for 72 hours. The weight-average molecular weight (Mw) of the resin scraped off the coated plate was measured before and after heating, and the heat resistance of the resin was evaluated according to the following criteria based on the degree to which the molecular weight of the resin after heating had decreased compared to the molecular weight of the resin before heating. ◎ (Very good): Molecular weight reduction rate after heating is less than 5% ○ (Excellent): Molecular weight reduction rate after heating is 5% or more but less than 10% △ (lower limit of practical use): Molecular weight reduction rate after heating is 10% or more but less than 20% × (impossible to use): molecular weight reduction rate after heating is 20% or more

[0096] [Moisture and heat resistance] The resulting urethane urea resin was coated onto an aluminum plate to a dry coating thickness of 50 μm and then dried in an electric oven at 80°C for 3 minutes to obtain a urethane urea resin-coated plate. The coated plate was then stored for 7 days in a thermo-hygrostat at 85°C and 85% relative humidity (85% RH). The weight-average molecular weight of the resin scraped off the coated plate was measured before and after the 7-day storage period. The moisture and heat resistance of the resin was evaluated according to the following criteria based on the degree of decrease in the molecular weight of the resin after storage compared to the molecular weight of the resin before storage. ◎ (Very good): Molecular weight reduction rate after storage in a constant temperature and humidity chamber is less than 5% ○ (Excellent): Molecular weight reduction rate after storage in a constant temperature and humidity chamber is 5% or more but less than 10% △ (lower limit of practical use): Molecular weight reduction rate after storage in a constant temperature and humidity chamber is 10% or more but less than 20% × (impossible to use): Molecular weight reduction rate after storage in a constant temperature and humidity chamber is 20% or more

[0097] <Production of Adhesive Composition> [Example 26] 100.0 parts of urethane urea resin (D-1) solution as the main component and 0.98 parts of curing agent (G-1) as the curing component were added and mixed with stirring at 25° C. to obtain an adhesive composition.

[0098] [Examples 27 to 74, Comparative Examples 9 to 16] The same procedure as in Example 1 was carried out except that the blending compositions were changed as shown in Tables 4 to 8, to obtain adhesive compositions of Examples 27 to 74 and Comparative Examples 9 to 16.

[0099] <Evaluation of Adhesive Composition> The adhesive compositions obtained were subjected to the following evaluations, and the results are shown in Tables 4 to 8.

[0100] [Initial adhesive strength] The adhesive composition was applied to 50 μm thick PET film, PEN film, or PPS film to a dry film thickness of 15 μm, and then dried at 80°C for 3 minutes to prepare an adhesive sheet. The prepared adhesive sheet was laminated to the same film as the coated substrate, and then heated in an electric oven at 150°C for 60 minutes. The resulting "substrate / thermosetting adhesive composition / substrate" structure was used as the evaluation structure. This evaluation structure was cut into 10 mm wide pieces and subjected to a T-peel test at 23°C and 50% RH at a pulling rate of 50 mm / min. The adhesive strength was evaluated according to the following evaluation criteria. ◎ (Excellent): The substrate was destroyed 〇 (Excellent): 3N / cm or more △ (lower practical limit): 1N / cm or more and less than 3N / cm × (not practical): Less than 1 N / cm

[0101] [Adhesive strength after durability test] The adhesive strength of the 10 mm wide evaluation structure consisting of the "PPS / thermally cured adhesive composition / PPS" obtained above was measured after a moist heat resistance test and a heat resistance test.

[0102] (Adhesive strength after heat and humidity resistance test) The 10 mm wide evaluation constructs consisting of the "PPS / thermocured adhesive composition / PPS" obtained above were subjected to a pressure cooker test (PCT) at 121°C, 100% RH, and 168 hours. After leaving the specimens for 24 hours at 23°C and 50% RH, a T-peel test was performed at a pulling rate of 50 mm / min at 23°C and 50% RH, and the adhesive strength was evaluated according to the following criteria. ◎ (Excellent): The substrate was destroyed 〇 (Excellent): 3N / cm or more △ (lower practical limit): 1N / cm or more and less than 3N / cm × (not practical): Less than 1 N / cm

[0103] (Adhesive strength after heat resistance test) The 10 mm wide evaluation structure consisting of the "PPS / thermocured adhesive composition / PPS" obtained above was treated in an electric oven at 150°C for 168 hours. After leaving it to stand for 24 hours in an atmosphere of 23°C and 50% RH, a T-peel test was performed at a pulling rate of 50 mm / min in an atmosphere of 23°C and 50% RH, and the adhesive strength was evaluated according to the following evaluation criteria. ◎ (Excellent): The substrate was destroyed 〇 (Excellent): 3N / cm or more △ (lower practical limit): 1N / cm or more and less than 3N / cm × (not practical): Less than 1 N / cm

[0104] [Appearance evaluation] The adhesive composition was applied to a 50 μm thick PPS film to a dry thickness of 15 μm, and then dried at 80°C for 3 minutes to produce an adhesive sheet. The prepared adhesive sheet was laminated at 120°C to a solid electrolyte membrane (Nafion® NR212, manufactured by Chemours) and then aged in an 80°C electric oven for 7 days. Five samples of the resulting "PPS / thermocured adhesive composition / solid electrolyte membrane" composition were prepared as evaluation samples. These evaluation samples were evaluated according to the following criteria. 〇 (Excellent): No lifting or peeling in all 5 points △ (lower limit of practical use): 1 or 2 out of 5 points show lifting or peeling × (Not practical): 3 or more out of 5 points showing lifting or peeling

[0105] As shown in Tables 1 to 3, the urethane urea resins of the present invention and their cured products obtained good results in terms of the heat resistance and moist heat resistance of the urethane urea resin, and the initial adhesive strength, moist heat resistance, heat resistance, and appearance evaluation of the cured products. On the other hand, the comparative resins and their cured products did not obtain satisfactory results in all of the heat resistance and moist heat resistance of the urethane urea resin, and the initial adhesive strength, moist heat resistance, heat resistance, and appearance evaluation of the cured products.

[0106] [Table 4]

[0107] [Table 5]

[0108] [Table 6]

[0109] [Table 7]

[0110] [Table 8] [Industrial Applicability]

[0111] The urethane urea resin and its cured product of the present invention can be suitably used in fuel cells and water electrolysis devices. While the present invention has been described above in terms of specific embodiments, modifications and improvements that are obvious to those skilled in the art are also included within the scope of the present invention.

Claims

1. A urethane urea resin containing, as structural units, a polyol compound (A), a polyisocyanate compound (B), and an amine compound (C), at least one of the polyol compound (A), the polyisocyanate compound (B), and the amine compound (C) has an alicyclic structure; The polyol compound (A) contains a diol compound (a1) having a carboxy group, the total content of components having an alicyclic structure is 5.0 to 40.0% by mass relative to 100% by mass of the total components constituting the urethane urea resin, The acid value of the urethane urea resin is 5 to 30 mgKOH / g, A urethane urea resin characterized in that the urea bond concentration in the urethane urea resin is 0.20 to 1.00 mmol / g.

2. the polyol compound (A) further contains at least one of a dimer diol (a2) and a polycarbonate polyol (a3); the polyisocyanate compound (B) contains a polyisocyanate (b1) having an alicyclic structure, 2. The urethane urea resin according to claim 1, wherein the amine compound (C) contains a diamine (c1) having an alicyclic structure.

3. 3. A method for producing the urethane urea resin according to claim 1 or 2 in a mixed solvent comprising two solvents: a solvent (S1) having a hydrogen bond term δh of Hansen's solubility parameters of 0 or more and less than 10, and a solvent (S2) having a δh of 10 to 25, wherein the proportion of solvent (S2) in 100 mass% of the mixed solvent is 10 to 40 mass%.

4. A composition comprising the urethane urea resin according to claim 1 or 2 and a curing agent, the curing agent contains at least one selected from the group consisting of an epoxy compound, a carbodiimide compound, an oxazoline compound, and an aziridine compound; An adhesive composition characterized in that the ratio (Y / X) of carboxy groups (X) in the urethane urea resin to functional groups (Y) in the curing agent is 1.0 / 1.0 to 5.0 / 1.

0.

5. A cured product obtained by curing the adhesive composition according to claim 4.

6. An adhesive sheet having an adhesive layer made of the adhesive composition according to claim 4 and a substrate.

7. A fuel cell member comprising the adhesive sheet according to claim 5.

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