Curable composition, cured product, and two-component curable composition

Abstract

The present invention addresses the problem of providing a curable composition that cures rapidly without the use of a tin-based curing catalyst and is capable of forming a cured product which exhibits superior storage stability and mechanical properties and which cures in a desired thermal environment, providing a curable composition that exhibits superior adhesion properties, and providing a two-part curable composition.　A curable composition according to the present invention is characterized by containing: a (meth)acrylic polymer (A) that has a group represented by a prescribed formula and contains at least 1500 ppm elemental silicon; and a salt compound (B) composed of an acid having an acid dissociation constant (pKa) of less than 3.5 and a base having a pKa of at least 10.

Description

[Technical Field]

[0001] The present invention relates to a curable composition, a cured product, and a two-component curable composition. [Background technology]

[0002] Polymers containing reactive silicon groups in their molecules are known as compositions that crosslink and cure through the formation of siloxane bonds accompanied by hydrolysis of silyl groups due to moisture in the atmosphere or on the substrate. Among these, polymers containing reactive silicon groups such as alkoxysilyl groups are widely used as adhesives, sealants, paints, etc. in construction and building material-related applications, automotive-related applications, etc.

[0003] In particular, it is known that by using a polyoxyalkylene polymer having a reactive silicon group of a specific structure, a (meth)acrylate polymer, or a polysiloxane compound, it is possible to obtain a curable composition that has fast curing properties and excellent adhesiveness and storage stability (see, for example, Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-101499 [Patent Document 2] International Publication No. 2009 / 104700 [Patent Document 3] International Publication No. 2010 / 110107 [Patent Document 4] Japanese Patent Application Publication No. 2018-016796 Summary of the Invention [Problem to be solved by the invention]

[0005] Curable compositions containing polymers having reactive silicon groups in the molecule are usually cured using a catalyst such as a tin-based compound to accelerate the curing reaction, but the use of tin-based compounds is undesirable from the viewpoints of environmental impact and toxicity to the human body.

[0006] The curable compositions described in Patent Documents 1 to 3 are characterized by being cured well without using a tin-based compound. However, the curable composition disclosed in Patent Document 1 has a polymer having a silyl group represented by a predetermined formula, which is highly reactive, and the reaction proceeds even with moisture in the air. Therefore, the curable composition needs to be stored in an airtight container or the like that blocks air, and there is a problem that the curable composition needs to be used up or discarded after being removed from the storage container or the like.

[0007] In view of the above circumstances, there is a need for the development of a curable composition that does not cure in a room temperature environment but cures upon a certain degree of heat treatment. The curable compositions disclosed in Patent Documents 2 to 4 are characterized by rapid curing at room temperature, but there is no mention of curing in a desired thermal environment.

[0008] An object of the present invention is to provide a curable composition that cures quickly without the use of a tin-based curing catalyst, has excellent storage stability and mechanical properties, and is capable of forming a cured product that cures under a desired thermal environment; a curable composition that has excellent adhesiveness; and a two-component curable composition. [Means for solving the problem]

[0009] The present invention relates to, for example, the following [1] to [8]. [1] A curable composition comprising: a (meth)acrylic polymer (A) having a group represented by formula (1) and containing 1,500 ppm or more of silicon; and a salt compound (B) composed of an acid having an acid dissociation constant (pKa) of less than 3.5 and a base having a pKa of 10 or more. Formula (1):-X-CH2-SiR 1 3 [In formula (1), R 1are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group, and R 1 at least one of the groups is an alkoxy group or a hydroxyl group; X is —O—, —COO—, —S—, —N(R 2 )-, -CH(OH)-CH2-O-, -O-CO-NH- or -N(R 2 )-CO-N(R 3 )-, and R 2 and R 3 is a hydrogen atom, a hydrocarbon group, or a halogenated hydrocarbon group, and R 2 and R 3 may be the same or different.]

[0010] [2] The curable composition according to [1], which contains 0.01 to 50 parts by mass of the salt compound (B) based on 100 parts by mass of the (meth)acrylic polymer (A).

[0011] [3] The curable composition according to [1] or [2], wherein the (meth)acrylic polymer (A) has a group represented by the formula (1) at least at a molecular chain terminal.

[0012] [4] The curable composition according to any one of [1] to [3], wherein the (meth)acrylic polymer (A) has a number average molecular weight (Mn) of 1,000 to 100,000.

[0013] [5] The curable composition according to any one of [1] to [4], wherein the salt compound (B) is a salt compound composed of an organic acid having a pKa of 1 or more and less than 3.5 and an organic base having a pKa of 10 or more and less than 15. [6] The curable composition according to any one of [1] to [5], which contains 1 to 1,000 parts by mass of the epoxy resin (C) per 100 parts by mass of the (meth)acrylic polymer (A). [7] A cured product obtained from the curable composition according to any one of [1] to [6] above. [8] A two-component curable composition comprising a first part containing the curable composition according to any one of [1] to [6] above and a polymerization initiator, and a second part containing a reducing agent. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a curable composition that cures quickly without the use of a tin-based curing catalyst, has excellent storage stability and mechanical properties, and can form a cured product that cures under a desired thermal environment; a curable composition that has excellent adhesiveness; and a two-component curable composition. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be specifically described below. [Curable composition] The curable composition of one embodiment of the present invention (hereinafter also referred to as "the composition of the present invention") contains a (meth)acrylic polymer (A) and a salt compound (B), which will be described below. The composition of the present invention can be used as a one-component curable composition.

[0016] In this specification, (meth)acrylic is used as a general term for acrylic and methacrylic and may be either acrylic or methacrylic, (meth)acrylate is used as a general term for acrylate and methacrylate and may be either acrylate or methacrylate, and (meth)acryloyl is used as a general term for acryloyl and methacryloyl and may be either acryloyl or methacryloyl.

[0017] <(Meth)acrylic polymer (A)> The (meth)acrylic polymer (A) (hereinafter also referred to as "polymer (A)") is a polymer having a group represented by formula (1) and containing 1,500 ppm or more of silicon element.

[0018] Formula (1):-X-CH2-SiR 1 3 [In formula (1), R 1 are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group, and R 1 at least one of the groups is an alkoxy group or a hydroxyl group; X is —O—, —COO—, —S—, —N(R 2)-, -CH(OH)-CH2-O-, -O-CO-NH- or -N(R 2 )-CO-N(R 3 )-, and R 2 and R 3 is a hydrogen atom, a hydrocarbon group, or a halogenated hydrocarbon group, and R 2 and R 3 may be the same or different.]

[0019] Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, a 1-methylpentyl group, a 4-methyl-2-pentyl group, a 3,3-dimethylbutyl group, a 2-ethylbutyl group, an n-heptyl group, a 1-methylhexyl group, an n-octyl group, an isooctyl group, a 1-methylheptyl group, a 2-ethylhexyl group, a 2-propylpentyl group, an n-nonyl group, Examples of the alkyl group include straight-chain and branched alkyl groups such as 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl, and are preferably alkyl groups having 1 to 10 carbon atoms, more preferably alkyl groups having 1 to 3 carbon atoms. The alkyl groups may be straight-chain or branched.

[0020] Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, an n-pentyloxy group, an isopentyloxy group, a neopentyloxy group, an n-hexyloxy group, a 1-methylpentyloxy group, a 4-methyl-2-pentyloxy group, a 3,3-dimethylbutyloxy group, a 2-ethylbutyloxy group, an n-heptyloxy group, a 1-methylhexyloxy group, an n-octyloxy group, an isooctyloxy group, a 1-methylheptyloxy group, a 2-ethylhexyloxy group, a 2-propylpentyloxy group, Examples of such alkoxy groups include linear and branched alkoxy groups such as n-nonyloxy, 2,2-dimethylheptyloxy, 2,6-dimethyl-4-heptyloxy, 3,5,5-trimethylhexyloxy, n-decyloxy, n-undecyloxy, 1-methyldecyloxy, n-dodecyloxy, n-tridecyloxy, 1-hexylheptyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, and n-eicosyloxy, and are preferably alkoxy groups having 1 to 10 carbon atoms, and more preferably 1 to 3 carbon atoms. The alkoxy group may be linear or branched.

[0021] R 2 and R 3 Examples of the hydrocarbon group in the formula (I) include alkyl groups having 1 to 18 carbon atoms, preferably 1 to 3 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, 2-ethylhexyl, n-octyl, and isooctyl groups; cycloalkyl groups having 3 to 18 carbon atoms, preferably 5 to 8 carbon atoms, such as cyclopentyl and cyclohexyl groups; alkenyl groups having 2 to 18 carbon atoms, preferably 2 to 5 carbon atoms, such as vinyl, allyl, 3-butenyl, and 5-hexenyl groups; and aryl groups having 6 to 18 carbon atoms, preferably 6 to 10 carbon atoms, such as phenyl, naphthyl, and anthryl groups.

[0022] R 2 and R 3The halogenated hydrocarbon group in the formula (I) is a group in which at least some of the hydrogen atoms constituting the hydrocarbon group have been substituted with halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. R 2 and R 3 is preferably a hydrogen atom or a hydrocarbon group, more preferably a hydrocarbon group.

[0023] -SiR 1 Examples of the group represented by 3 include a dimethylmethoxysilyl group, a dimethylethoxysilyl group, a methyldimethoxysilyl group, a methyldiethoxysilyl group, a trimethoxysilyl group, a triethoxysilyl group, a dimethylisopropoxysilyl group, a methyldiisopropoxysilyl group, and a triisopropoxysilyl group.

[0024] From the viewpoint of curability and mechanical properties, the polymer (A) has a group represented by formula (1) and contains 1,500 ppm or more, preferably 1,600 to 20,000 ppm, and more preferably 1,700 to 10,000 ppm of silicon element. Here, "ppm" means wt ppm. In one embodiment, the polymer (A) preferably has a group represented by formula (1) at the molecular chain terminal of the polymer. The silicon element content derived from the group represented by formula (1) in the polymer (A) can be calculated from the charge ratio, but can also be measured by ICP atomic emission spectroscopy. Details are described in the Examples section.

[0025] (Meth)acrylic acid alkyl ester (a1) The polymer (A) is preferably a polymer of a polymerizable monomer component containing a (meth)acrylic acid alkyl ester (a1) (hereinafter also referred to as "monomer (a1)") having an alkyl group with a carbon number of 1 to 12. That is, the polymer (A) preferably has a structural unit derived from the monomer (a1).

[0026] The alkyl group may be straight or branched. Examples of the monomer (a1) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, and lauryl (meth)acrylate.

[0027] The monomer (a1) can be used alone or in combination of two or more. The proportion of the monomer (a1) in the polymerizable monomer components constituting the polymer (A) is preferably 20% by mass or more, more preferably 20 to 99% by mass, even more preferably 20 to 97% by mass, and particularly preferably 22 to 96% by mass. The polymer (A) may have structural units derived from the monomer (a1) in the same range among all structural units. When a (meth)acrylic acid alkyl ester (a1) having an alkyl group with 8 to 12 carbon atoms is used in the above range, a (meth)acrylic polymer with excellent mechanical properties can be obtained.

[0028] <Hydrolyzable silyl group-containing (meth)acryloyl monomer (a2)> It is preferable that the polymer (A) further contains a structural unit derived from a hydrolyzable silyl group-containing (meth)acryloyl monomer (a2) (hereinafter also referred to as "monomer (a2)") that is copolymerizable with the monomer (a1) and has a group represented by formula (1). As the monomer (a2), for example, a compound represented by formula (a2-1) is preferable.

[0029] [ka] In formula (a2-1), R a is a hydrogen atom or a methyl group, and R 1 is R in Eq. (1) 1 is synonymous with.

[0030] Examples of the compound represented by formula (a2-1) include (meth)acryloxy group-containing silanes such as (meth)acryloxymethyldimethylmethoxysilane, (meth)acryloxymethyldimethylethoxysilane, ((meth)acryloxymethyl)methyldimethoxysilane, ((meth)acryloxymethyl)methyldiethoxysilane, (meth)acryloxymethyltrimethoxysilane, and (meth)acryloxymethyltriethoxysilane.

[0031] Monomer (a2) includes a monomer in which OCN-CH2-SiR is bonded to a hydroxy group of a hydroxyalkyl (meth)acrylate such as 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate, or to an amino group of an aminoalkyl (meth)acrylate such as 2-aminoethyl (meth)acrylate. 1 The compound represented by 3 (R 1 The symbol OCN—CH—SiR has the same meaning as the symbol in formula (1). 1 Specific examples of the compound represented by 3 will be described later.

[0032] The monomer (a2) can be used alone or in combination of two or more. The proportion of monomer (a2) in the polymerizable monomer components constituting polymer (A) is preferably 0.01 to 10 mass%, more preferably 0.1 to 5 mass%. Polymer (A) can have structural units derived from monomer (a2) in the same range among all structural units. When monomer (a2) is used in the above range, a group represented by formula (1) can be introduced into polymer (A). Therefore, the obtained polymer (A) has appropriate crosslinkability and is suitable for applications in which a crosslinked product is formed.

[0033] Other Monomers (a3) The polymer (A) may further contain a structural unit derived from a monomer (a3) ​​other than the monomers (a1) and (a2) within the scope of the present invention.

[0034] Examples of the other monomers (a3) ​​include: (meth)acrylic acid alkyl esters having an alkyl group carbon number of 13 or more, preferably an alkyl group carbon number of 22, such as n-tridecyl (meth)acrylate, isodecyl (meth)acrylate, n-myristyl (meth)acrylate, isomyristyl (meth)acrylate, n-pentadecyl (meth)acrylate, isopentadecyl (meth)acrylate, n-cetyl (meth)acrylate, isocetyl (meth)acrylate, n-heptadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, n-stearyl (meth)acrylate, isostearyl (meth)acrylate, n-nonadecyl (meth)acrylate, isononadecyl (meth)acrylate, n-eicosyl (meth)acrylate, and isoeicosyl (meth)acrylate; (meth)acrylates containing an alicyclic hydrocarbon group or an aromatic hydrocarbon group, such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, and phenyl (meth)acrylate; alkoxyalkyl (meth)acrylates such as methoxymethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate; polyalkylene glycol (meth)acrylates such as methoxypolyethylene glycol mono(meth)acrylate, ethoxypolyethylene glycol mono(meth)acrylate, octoxypolyethylene glycol mono(meth)acrylate, lauroxypolyethylene glycol mono(meth)acrylate, stearoxypolyethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, and polypropylene glycol mono(meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; (meth)acrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid; carboxy group-containing monomers such as carboxy group-containing (meth)acrylates such as β-carboxyethyl (meth)acrylate, 5-carboxypentyl (meth)acrylate, succinic acid mono(meth)acryloyloxyethyl ester, and ω-carboxypolycaprolactone mono(meth)acrylate; Monomers containing an acid anhydride group, such as phthalic anhydride and maleic anhydride; dialkylaminoalkyl (meth)acrylates such as 2-dimethylaminoethyl (meth)acrylate and 2-diethylaminoethyl (meth)acrylate; (Meth)acrylamides; N-alkyl(meth)acrylamides such as N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, and N-hexyl(meth)acrylamide; amide group-containing monomers such as N,N-dialkyl(meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide; Cyano group-containing monomers such as (meth)acrylonitrile; Nitrogen-based heterocycle-containing monomers such as N-vinylpyrrolidone, N-vinylmorpholine, N-vinylcaprolactam, (meth)acryloylmorpholine, N-cyclohexylmaleimide, N-phenylmaleimide, N-laurylmaleimide, and N-benzylmaleimide; Styrene derivatives such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, divinylbenzene, and indene; vinyl ester compounds such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, and vinyl cinnamate;

[0035] Among the other monomers (a3), (meth)acrylic acid alkyl esters other than the monomer (a1) and polyalkylene glycol (meth)acrylates are preferred, and (meth)acrylic acid alkyl esters other than the monomer (a1) are more preferred.

[0036] The other monomers (a3) ​​can be used alone or in combination of two or more. The proportion of the other monomer (a3) ​​in the polymerizable monomer components constituting the polymer (A) is preferably 1 to 65 mass %, more preferably 5 to 60 mass %. The polymer (A) may have structural units derived from the other monomer (a3) ​​in the total structural units in a similar range.

[0037] <Mercapto group-containing compound (d)> During the production of the polymer (A), a mercapto group-containing compound (d) may be used as a chain transfer agent. The mercapto group-containing compound (d) acts as a chain transfer agent due to its functional group (-SH) with high chain transfer properties in radical polymerization. When polymerizable monomer components are polymerized in the presence of the mercapto group-containing compound (d), a structural unit derived from the mercapto group-containing compound (d), particularly a mercapto group-containing compound having a group represented by formula (1), can be used to introduce the group represented by formula (1) into the molecular chain terminal of the polymer. Furthermore, by introducing the mercapto group-containing compound (d) represented by formula (1) into a polymer having a polymerizable unsaturated group via an ene-thiol reaction, the group represented by formula (1) can also be introduced into the polymer. Curable compositions using polymer (A) having a group represented by formula (1) at the molecular chain terminal exhibit excellent curing speed and mechanical properties.

[0038] When the monomer (a2) is used, the group represented by formula (1) in the monomer (a2) and the group represented by formula (1) in the mercapto group-containing compound (d) may be the same or different. The mercapto group-containing compound (d) is preferably a compound represented by formula (d-1). Formula (d-1): HS-CH2-SiR 1 3 In formula (d-1), R 1 is R in equation (1). 1 is synonymous with.

[0039] Among the mercapto group-containing compounds (d), examples of compounds represented by formula (d-1) include mercaptomethyldimethylmethoxysilane, mercaptomethyldimethylethoxysilane, mercaptomethyldimethylisopropoxysilane, mercaptomethylmethyldimethoxysilane, mercaptomethylmethyldiethoxysilane, mercaptomethylmethyldiisopropoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, and mercaptomethyltriisopropoxysilane. Among these, mercaptomethyldimethylmethoxysilane, mercaptomethylmethyldimethoxysilane, mercaptomethyltrimethoxysilane, and mercaptomethyltriethoxysilane are preferred. By using a compound represented by formula (d-1), a group represented by formula (1) can be introduced into the molecular chain terminal of the polymer (A).

[0040] Other mercapto group-containing compounds (d) include, for example, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, lauryl mercaptan, mercaptopropylmethyldimethoxysilane, mercaptopropyltrimethoxysilane, and other mercapto group-containing compounds.

[0041] The compound (d) can be used alone or in combination of two or more. The mercapto group-containing compound (d) is preferably used in an amount of 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, per 100 parts by mass of the total of the polymerizable monomer components. In this embodiment, the number average molecular weight of the polymer (A) can be adjusted to an appropriate range.

[0042] <Production of Polymer (A)> The polymer (A) can be obtained by various polymerization methods, and the method is not particularly limited, but it is preferable to obtain it by, for example, the following method. Note that the methods (i) to (iv) may be used in any combination.

[0043] (i) A method of copolymerizing a monomer (a2) having a polymerizable unsaturated group and a group represented by formula (1) with the above-mentioned monomer (a1) having a (meth)acrylic structure. (ii) A method of polymerizing a monomer (a1) having a (meth)acrylic structure in the presence of a mercapto group-containing compound (d) having a group represented by formula (1) as a chain transfer agent. (iii) A method of reacting a polymer having a reactive functional group obtained by copolymerizing a compound having a polymerizable unsaturated group and a reactive functional group (e.g., a hydroxy group, an isocyanate group, or an amino group) and a monomer component including monomer (a1) with a compound (e) having a group that undergoes an addition reaction with the reactive functional group and that can introduce a group represented by formula (1) into the polymer by the addition reaction.

[0044] Examples of the compound (e) include compounds represented by formula (e-1) and formula (e-2) (hereinafter also referred to as "compound (e-1)" and "compound (e-2)", respectively). Formula (e-1):OCN-CH2-SiR 1 3 [R 1 has the same meaning as the same symbol in formula (1).

[0045] Examples of the compound (e-1) include 1-isocyanatemethyldimethylmethoxysilane, 1-isocyanatemethyldimethylethoxysilane, 1-isocyanatemethyldimethylisopropoxysilane, (1-isocyanatemethyl)methyldimethoxysilane, (1-isocyanatemethyl)methyldiethoxysilane, (1-isocyanatemethyl)methyldiisopropoxysilane, 1-isocyanatemethyltrimethoxysilane, 1-isocyanatemethyltriethoxysilane, and 1-isocyanatemethyltriisopropoxysilane. Among these, 1-isocyanatemethyldimethylmethoxysilane, (1-isocyanatemethyl)methyldimethoxysilane, 1-isocyanatemethyltrimethoxysilane, and 1-isocyanatemethyltriethoxysilane are preferred.

[0046] Formula (e-2):R4 -CH2-SiR 1 3 [R 1 is the same as the same symbol in formula (1), and R 4 is a glycidyloxy group, an amino group, an alkylamino group, an (aminoalkyl)amino group, an (N,N-dialkylaminoalkyl)amino group, or a halogenated hydrocarbon group.

[0047] Examples of the compound (e-2) include aminomethyltrimethoxysilane, aminomethyltriethoxysilane, (aminoethylamino)methyltrimethoxysilane, (N,N-dimethylamino)ethylaminomethyltrimethoxysilane, and glycidyloxymethyltrimethoxysilane. The compound (e) can be used alone or in combination of two or more kinds. The compound (e) is preferably used in an amount of 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, based on 100 parts by mass of the total of the polymerizable monomer components.

[0048] (iv) A method in which the monomer (a1) is polymerized by a living polymerization method, a functional group such as an alkenyl group or a hydroxyl group is introduced into the molecular chain terminal, and then the obtained polymer is reacted with the compound (d) or the compound (e), etc.

[0049] The polymer (A) can be produced by utilizing known polymerization methods such as cationic polymerization, anionic polymerization, and radical polymerization, as in the above-mentioned methods (i) to (iv). The method is not particularly limited, but radical polymerization is preferred from the viewpoints of versatility of monomers and industrial productivity. Examples of radical polymerization methods include living radical polymerization, which can introduce a specific functional group (e.g., a group represented by formula (1)) into a controlled position such as an end, and free radical polymerization, which copolymerizes predetermined monomer units using a polymerization initiator.

[0050] Living polymerization methods include living cationic polymerization, living anionic polymerization, and living radical polymerization, but living radical polymerization is preferred from the perspective of industrial productivity. Examples of living radical polymerization methods that can be used include atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT) polymerization, nitroxide-mediated polymerization (NMP), organotellurium-mediated polymerization (TERP), and iodine-mediated polymerization (IRP). By selecting the reaction conditions, polymers with terminal functional groups can be obtained.

[0051] In the free radical polymerization method, for example, a reaction vessel is charged with polymerizable monomer components and, if necessary, a mercapto group-containing compound (d), and a polymerization initiator is added, followed by reaction at a reaction temperature of about 40 to 90°C for 2 to 20 hours. In the reaction, a polymerization solvent may be added as necessary. For example, the polymerization is carried out under an inert gas atmosphere such as nitrogen gas. Furthermore, during the polymerization reaction, the polymerizable monomer components, polymerization initiator, chain transfer agent, and polymerization solvent may be appropriately added.

[0052] Examples of polymerization initiators include azo compound-based polymerization initiators, peroxide-based polymerization initiators, and photoradical polymerization initiators. It is more preferable not to use a metal catalyst. Polymer (A) produced using such a polymerization initiator does not contain any metal components derived from the catalyst, and therefore, can improve the inhibition of crosslinking reactions and coloration. Furthermore, since depolymerization reactions caused by metal components can be suppressed, a cured product with excellent durability for use in various applications can be provided.

[0053] Examples of the azo compound polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2-(carbamoylazo)isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, ... Examples of suitable azobis(2-amidinopropane) dihydrochloride include 2,2'-azobis(N,N'-dimethyleneisobutylamidine), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide], 2,2'-azobis(isobutylamide) dihydrate, 4,4'-azobis(4-cyanopentanoic acid), 2,2'-azobis(2-cyanopropanol), dimethyl-2,2'-azobis(2-methylpropionate), and 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].

[0054] Examples of peroxide polymerization initiators include t-butyl hydroperoxide, cumene hydroperoxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, caproyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t-butyl peroxypivalate, and 2,2-bis(4,4-di-t-butylperoxycyclohexyl). Examples include propane, 2,2-bis(4,4-di-t-amylperoxycyclohexyl)propane, 2,2-bis(4,4-di-t-octylperoxycyclohexyl)propane, 2,2-bis(4,4-di-α-cumylperoxycyclohexyl)propane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)butane, and 2,2-bis(4,4-di-t-octylperoxycyclohexyl)butane.

[0055] As the photoradical polymerization initiator, compounds conventionally used as photoradical polymerization initiators are preferred, for example, benzoin-based initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin propyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1 ... Acetophenone initiators such as cyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, and N,N-dimethylaminoacetophenone; anthraquinone initiators such as 2-methylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, and 2-isopropylthioxanthone; thioxanthone-based initiators such as acetophenone dimethyl ketal and benzyl methyl ketal; benzophenone-based initiators such as benzophenone, methylbenzophenone, 4-phenylbenzophenone, 2,4,6-trimethylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, Michler's ketone and 4-benzoyl-4'-methyldiphenyl sulfide; 2,4 Acylphosphine oxide initiators such as bis(2,6-dimethoxybenzoyl)-2,4,4'-trimethylpentylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; oxime ester initiators such as 1-[4-(phenylthio)phenyl]octane-1,2-dione 2-(O-benzoyloxime); camphorquinone and α-hydroxyketones.

[0056] The photoradical polymerization initiator may be used alone or in combination of two or more kinds. The photoradical polymerization initiator may be combined with a sensitizer, and examples of the sensitizer include anthracene compounds such as 9,10-dibutoxyanthracene and 9,10-bis(acyloxy)anthracene.

[0057] The polymerization initiators can be used alone or in combination. The polymerization initiator may be added successively multiple times. The amount of the polymerization initiator used is usually 0.001 to 2 parts by mass, and preferably 0.002 to 1 part by mass, relative to 100 parts by mass of the polymerizable monomer component. By using the polymerization initiator within the above range, the number average molecular weight of the polymer (A) can be adjusted within an appropriate range.

[0058] The polymerization solvent is preferably an organic solvent. Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, and n-octane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane; ethers such as diethyl ether, diisopropyl ether, 1,2-dimethoxyethane, dibutyl ether, tetrahydrofuran, dioxane, anisole, phenylethyl ether, and diphenyl ether; halogenated hydrocarbons such as chloroform, carbon tetrachloride, 1,2-dichloroethane, and chlorobenzene; esters such as ethyl acetate, propyl acetate, butyl acetate, and methyl propionate; ketones such as acetone, acetylacetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, and cyclohexanone; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; nitriles such as acetonitrile and benzonitrile; and sulfoxides such as dimethyl sulfoxide and sulfolane. The polymerization solvent may be used alone or in combination of two or more kinds.

[0059] <Physical properties of polymer (A)> The number average molecular weight (Mn) of the polymer (A) is preferably 1,000 or more, more preferably 3,000 or more, and even more preferably 5,000 or more, from the viewpoint of the viscosity of the polymer and the mechanical properties of the resulting cured product, and is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 30,000 or less, from the viewpoint of the viscosity of the polymer.

[0060] The number average molecular weight (Mn) is measured by gel permeation chromatography (GPC). The glass transition temperature (Tg) of the polymer (A) is preferably from −80° C. to 100° C. Tg is determined by differential scanning calorimetry (DSC). Details of the measurement conditions for GPC and DSC will be described in the Examples section below.

[0061] <Polymer (A) Content> The composition of the present invention may contain one or more polymers (A). The composition of the present invention preferably contains a total of 5% by mass or more of the polymer (A), more preferably 8 to 95% by mass, and even more preferably 10 to 90% by mass.

[0062] <Salt Compound (B)> The composition of the present invention contains a salt compound (B) composed of an acid having an acid dissociation constant (pKa) of less than 3.5 and a base having a pKa of 10 or more. The salt compound (B) is a compound that melts, dissolves, or is activated by applying a temperature above a certain level, and functions as a curing agent for at least the polymer (A), i.e., a so-called latent curing agent. By including the salt compound (B) composed of an acid and a base having a predetermined pKa value in the composition of the present invention, the pot life of the composition of the present invention is extended, a cured product that cures under a desired thermal environment can be formed, and a curable composition with excellent storage stability can be obtained. Examples of acids with a pKa of less than 3.5 include: Carboxylic acids such as o-phthalic acid (2.9), acetoacetic acid (3.58), maleic acid (1.93); halogenated carboxylic acids such as chloroethanoic acid (2.87), dichloroethanoic acid (1.35), trichloroethanoic acid (0.66), fluoroethanoic acid (2.59), bromoethanoic acid (2.90), iodoethanoic acid (3.18); Phenols such as 2,4,6-trinitrophenol (0.42); Sulfinic acids such as paratoluenesulfonic acid (2.4), trifluoromethanesulfonic acid (-14), etc. Examples of inorganic acids include hydrochloric acid (-8.0), nitric acid (-1.3), sulfuric acid (-3.0), phosphoric acid (2.12), hydrogen fluoride (3.17), and fluoroantimonic acid (-25).

[0063] Among these, from the viewpoints of the pot life and curability of the curable composition, acids having a pKa of -25.0 to 3.5 are preferred, acids having a pKa of -5.0 to 3.5 are more preferred, and acids having a pKa of 1 or more but less than 3.5 are even more preferred. Furthermore, organic acids are preferred from the viewpoint of good compatibility with the curable composition. The organic acid means carboxylic acids other than the inorganic acids, halogenated carboxylic acids, phenolic acids, and sulfinic acids.

[0064] Examples of bases with a pKa of 10 or more include: Nitrogen-containing heterocyclic compounds such as 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) (12.0) and 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) (12.7); alcohols such as choline hydroxide (13.9) and 2,2,2-trifluoroethanol (11.4); oximes such as benzophenone oxime (11.3) and acetophenone oxime (11.48); amines such as ethylamine (10.63), n-butylamine (10.59), cyclohexylamine (10.64); Sulfonium compounds such as trimethylsulfonium (27.0), dimethylbenzylsulfonium (22.6), and dimethylphenylsulfonium (25.2); Ammonium such as tetramethylammonium (35.1), trimethylphenylammonium (33.9), benzyltrimethylammonium (31.8); Imidazolium compounds such as 3-benzyl-2-(2,6-dimethylphenyl)-1,4,5-trimethyl-1H-imidazol-3-ium (28.8), 1,3-dibutyl-2-(2,6-dimethylphenyl)-4,5-dimethyl-1H-imidazol-3-ium (37.8), and 3-benzyl-2-(2,6-dimethylphenyl)-1-methyl-4,5-diphenyl-1H-imidazol-3-ium (29.1); thiazolium compounds such as 1,2-dimethylthiazolium (16.4); Azoliums such as 1,2,3-triazonium (24.9); Guanidinium, such as 1,1,2,2,3,3-hexamethylguanidinium (38.4); Phosphoniums such as tetramethylphosphonium (28.9), trimethylphenylphosphonium (27.7), and benzyltrimethylphosphonium (23.9); Pyridiniums such as N-methylpyridinium (27.7) and N-benzylpyridinium (24.1); Examples include inorganic bases such as sodium hydroxide (13).

[0065] Among these, bases having a pKa of 10 or more and less than 15 are preferred from the viewpoint of the pot life and curability of the curable composition, and bases having a pKa of 11 to 14 are more preferred. Furthermore, organic bases are preferred from the viewpoint of good compatibility with the curable composition. The organic base means a nitrogen-containing heterocyclic compound other than the inorganic bases, alcohol oxime, amine, sulfonium, ammonium, imidazolium, thiazolium, azolium, guanidium, phosphonium and pyridinium. The numbers in parentheses for the acids and bases mentioned above are pKa(H2O).

[0066] The salt compound (B) is commercially available. For example, U-CAT SA810 (o-phthalic acid salt of DBU), U-CAT SA506 (paratoluenesulfonic acid salt of DBU) (all manufactured by San-Apro), SI-60L, SI-80L, SI-100L, SI-110L (fluoroantimony salt of sulfonium, all manufactured by Sanshin Chemical Industry Co., Ltd.), Optomer Examples include CP-66, Optomer CP-77 (all manufactured by ADEKA), CXC-1614, CXC-2700, CXC-1612, CXC-1821, and CXC-1738 (all manufactured by King Industries).

[0067] <Salt compound (B) content> The composition of the present invention may contain one or more salt compounds (B). The content of the salt compound (B) in the composition of the present invention is preferably 0.01 to 100 parts by mass, more preferably 1 to 50 parts by mass, relative to 100 parts by mass of the polymer (A). Such an embodiment is preferred from the viewpoint of obtaining a curable composition excellent in pot life and curability.

[0068] <Epoxy resin (C)> The composition of the present invention may contain, in addition to the polymer (A) and the salt compound (B), an epoxy resin (C) as required. The epoxy resin (C) may be, for example, an epoxy compound having two or more epoxy groups in one molecule.

[0069] Examples of the epoxy resin (C) include: Bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol O type epoxy resin, bisphenol AD ​​type epoxy resin, hydrogenated bisphenol type epoxy resin, alkyl substituted bisphenol type epoxy resin, alkylene oxide modified bisphenol type epoxy resin, biphenyl type epoxy resin, resorcinol type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, ortho-cresol novolac type epoxy resin, dicyclopentadiene novolac type epoxy resin, biphenyl novolac type epoxy resin, naphthalene phenol novolac type epoxy resin, glycidyl amine type epoxy resin;

[0070] Diglycidyl ethers of bisphenols such as bisphenol A, bisphenol E, bisphenol F, bisphenol S, bisphenol O, and bisphenol AD, and 4,4-dihydroxybiphenyl (wherein the bisphenols and biphenyls may be hydrogenated (e.g., hydrogenated bisphenols), may have an alkyl substituent (e.g., alkyl-substituted bisphenols), or may be modified with alkylene oxides such as ethylene oxide and propylene oxide (e.g., alkylene oxide-modified bisphenols)), ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl ether compounds such as alkanediol diglycidyl ethers such as 1,8-octanediol diglycidyl ether, 1,10-decanediol diglycidyl ether, and 2,2-dimethyl-1,3-propanediol diglycidyl ether; alkanetriol diglycidyl ethers such as glycerin diglycidyl ether; polyalkylene glycol diglycidyl ethers such as diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, and hexaethylene glycol diglycidyl ether; and diglycidyl ethers of alicyclic-containing dimethanols such as 1,4-cyclohexanedimethanol diglycidyl ether;

[0071] Glycerin triglycidyl ether, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N,N'-tetraglycidyl-m-xylylenediamine, N,N,N',N'-tetraglycidylaminophenylmethane, triglycidyl isocyanurate, mN,N-diglycidylaminophenyl glycidyl ether, N,N-diglycidyl toluidine, N,N-diglycidylaniline, 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate;

[0072] The epoxy resin (C) may be used alone or in combination of two or more. The content of the epoxy resin (C) in the composition of the present invention is preferably 1 to 1,000 parts by mass, more preferably 10 to 500 parts by mass, per 100 parts by mass of the polymer (A). Such an embodiment is preferred from the viewpoint of obtaining a cured product with excellent strength. The epoxy equivalent of the epoxy resin (C) is not particularly limited, but is preferably 100 to 3000 g / eq., more preferably 100 to 1000 g / eq.

[0073] <Polymer (F)> The composition of the present invention may contain, in addition to the polymer (A), a polymer (F) having a polyether skeleton, if necessary. The polymer (F) preferably has a reactive silicon group, and particularly preferably has a group represented by the above formula (1).

[0074] The polymer (F) has a polyether skeleton as the main chain skeleton. The polyether skeleton is preferably a polyoxyalkylene skeleton, such as a polyoxyethylene skeleton, a polyoxypropylene skeleton, a polyoxybutylene skeleton, a polyoxytetramethylene skeleton, a polyoxyethylene-polyoxypropylene skeleton, or a polyoxypropylene-polyoxybutylene skeleton, with a polyoxypropylene skeleton being preferred. The polyoxyalkylene skeleton may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units. The repeating unit here is an oxyalkylene unit. The polymer (F) may have a urethane skeleton between the polyether skeletons.

[0075] The number average molecular weight (Mn) of the polymer (F) is preferably 10,000 to 50,000. If the number average molecular weight (Mn) satisfies such conditions, it is preferable in terms of compatibility with the polymer (A), handleability of the curable composition, and mechanical properties. The number average molecular weight (Mn) is measured by a GPC method.

[0076] Details of the GPC measurement conditions will be described in the Examples section below. By using the polymer (F) together with the polymer (A), a curable composition having excellent mechanical properties can be obtained.

[0077] When polymer (F) is used, the group represented by formula (1) in polymer (A) and the group represented by formula (1) in polymer (F) may be the same or different. In one embodiment, the polymer (F) preferably has a group represented by formula (1) at the molecular chain terminal of the polymer, and more preferably has a group represented by formula (1) at the molecular chain terminal of a polyether polymer.

[0078] The polymer (F) may be, for example, a polyether polymer having a terminal hydroxyl group and an OCN-CH2-SiR 1 The compound (e-1) (R 1 is synonymous with the same symbol in formula (1)) can be obtained by reacting with an isocyanate group.

[0079] The polymer (F) can also be prepared by obtaining a polyether polymer having an isocyanate group at its terminal from a polyether polymer, and combining the terminal isocyanate group of the polymer with R 4 -CH2-SiR 1 3(R 1 is the same as the same symbol described in formula (1), 4 The polyether polymer having a terminal isocyanate group can also be obtained by reacting an amino group, an alkylamino group, an (aminoalkyl)amino group, or an (N,N-dialkylaminoalkyl)amino group with an amino group as the terminal isocyanate group. A polyether polymer having a terminal isocyanate group can be obtained, for example, by a urethane reaction between a polyether polymer having a terminal hydroxyl group and a diisocyanate compound. Such a polyether polymer has a urethane skeleton between the polyether skeletons.

[0080] The polymer (F) can also be obtained by obtaining a polyether polymer having an amino group at its terminal from a polyether polymer, and then reacting the terminal amino group of the polymer with the isocyanate group of the compound (e-1).

[0081] Examples of the diisocyanate compound include: Aliphatic diisocyanates having 4 to 30 carbon atoms, such as ethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, and 2,2,4-trimethyl-1,6-hexamethylene diisocyanate; Alicyclic diisocyanates having 7 to 30 carbon atoms, such as isophorone diisocyanate, cyclopentyl diisocyanate, cyclohexyl diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylylene diisocyanate; Examples thereof include aromatic diisocyanates having 8 to 30 carbon atoms, such as phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, naphthylene diisocyanate, diphenyl ether diisocyanate, diphenylmethane diisocyanate, and diphenylpropane diisocyanate.

[0082] The composition of the present invention may contain one or more polymers (F). The content of polymer (F) in the composition of the present invention is preferably 10 to 900 parts by mass, more preferably 20 to 800 parts by mass, per 100 parts by mass of polymer (A). Such an embodiment is preferred from the viewpoint of obtaining a cured product having excellent mechanical properties.

[0083] <Other ingredients> In addition to the polymer (A), the composition of the present invention may contain, as necessary, one or more other components such as a plasticizer, a filler, silica, a pigment, a fiber, an antioxidant, a dehydrating agent, a silane coupling agent having an amino group, a curing catalyst, a tackifying resin, a dispersant, a rheology control agent, an antifoaming agent, and an adhesion promoter.

[0084] <Plasticizer> The composition of the present invention may further contain a plasticizer. The use of a plasticizer can improve the flexibility and extensibility of the cured product formed from the curable composition.

[0085] Examples of the plasticizer include phthalate esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, and diisononyl phthalate; non-phthalate esters such as 1,2-cyclohexanedicarboxylic acid diisononyl ester and trioctyl trimellitate; aliphatic carboxylic acid esters such as dioctyl adipate, diisodecyl succinate, dibutyl sebacate, and butyl oleate; alcohol esters such as diethylene glycol dibenzoate, triethylene glycol dibenzoate, and pentaerythritol ester; phosphate esters such as trioctyl phosphate and tricresyl phosphate; epoxidized soybean oil, 4,5- Examples of polymer plasticizers include epoxy plasticizers such as dioctyl epoxyhexahydrophthalate and benzyl epoxystearate; chlorinated paraffin; hydrocarbons such as normal paraffin and isoparaffin; polyethylene glycol and its derivatives, polypropylene glycol and its derivatives, for example, polyethers in which the hydroxyl groups of polyethylene glycol or polypropylene glycol are blocked with alkyl ethers, poly-α-methylstyrene, polystyrene oligomers such as polybutadiene, butadiene-acrylonitrile copolymer, polychloroprene, polyisoprene, polybutene, hydrogenated polybutene, and epoxidized polybutadiene, and (meth)acrylic polymers other than polymer (A).

[0086] One or more plasticizers can be used. In one embodiment, the content of the plasticizer in the composition of the present invention is preferably 10 to 400 parts by mass, more preferably 50 to 300 parts by mass, per 100 parts by mass of the polymer component, from the viewpoints of the coatability of the curable composition and the weather resistance of the cured product.

[0087] <Filler> The compositions of the present invention may further contain a filler. Examples of fillers include calcium carbonate such as heavy calcium carbonate, light calcium carbonate, colloidal calcium carbonate, semi-colloidal calcium carbonate, light calcium carbonate, and calcium carbonate obtained by surface-treating the surface of these calcium carbonates with a fatty acid or a resin acid-based organic substance; carbon black; magnesium carbonate; diatomaceous earth; calcined clay; clay; talc; titanium oxide; bentonite; ferric oxide; zinc oxide; activated zinc oxide; aluminum hydroxide; inorganic hollow bodies such as shirasu balloons, perlite, glass balloons, fly ash balloons, alumina balloons, zirconia balloons, and carbon balloons; phenolic resin balloons, epoxy resin balloons, etc. Examples of suitable fillers include organic resin hollow bodies (plastic balloons) such as silicon dioxide resin balloons, urea resin balloons, polyvinylidene chloride resin balloons, polyvinylidene chloride-(meth)acrylic resin balloons, polystyrene balloons, polymethacrylate balloons, polyvinyl alcohol balloons, styrene-(meth)acrylic resin balloons, and polyacrylonitrile balloons; powdery fillers such as resin beads, wood flour, pulp, cotton chips, mica, walnut flour, rice flour, graphite, fine aluminum powder, and flint powder; and fibrous fillers such as glass fiber, glass filament, carbon fiber, Kevlar fiber, and polyethylene fiber. Among these, calcium carbonate surface-treated with a fatty acid or the like is preferred from the viewpoint of dispersibility, and plastic balloons such as polystyrene balloons are preferred from the viewpoint of reducing specific gravity and providing heat insulation. The filler may be used alone or in combination of two or more kinds.

[0088] The content of the filler in the composition of the present invention is preferably 0.1 to 1,000 parts by mass, more preferably 1 to 500 parts by mass, based on 100 parts by mass of the polymer (A).

[0089] <Silica> The composition of the present invention may further contain silica. By using silica, the coatability of the curable composition is improved, and a cured product having excellent weather resistance and elongation can be obtained.

[0090] Examples of silica include fumed silica, and examples of silica include hydrophobic silica and hydrophilic silica, with hydrophobic silica being preferred. One or more types of silica can be used.

[0091] In one embodiment, the content of silica in the composition of the present invention is preferably 1 to 1,000 parts by mass, more preferably 5 to 500 parts by mass, based on 100 parts by mass of the polymer (A).

[0092] Pigments The composition of the present invention may further contain a pigment. Examples of pigments include inorganic pigments such as iron oxide, chromium oxide, titanium oxide, and cobalt aluminate, and organic pigments such as phthalocyanine blue and phthalocyanine green. The use of pigments is preferred from the viewpoint of improving color matching and weather resistance. One or more pigments can be used. In one embodiment, the content of the pigment in the composition of the present invention is preferably 1 to 200 parts by mass, more preferably 3 to 100 parts by mass, based on 100 parts by mass of the polymer (A).

[0093] <Fiber> The composition of the present invention may further contain fibers. Examples of fibers include inorganic fibers such as glass fibers and boron fibers, and organic fibers such as carbon fibers, aramid fibers, polyethylene fibers, and Zylon fibers. The use of fibers is preferred from the viewpoint of improving the strength of the cured product. One or more types of fibers can be used. In one embodiment, the content of the pigment in the composition of the present invention is preferably 1 to 1,000 parts by mass, more preferably 10 to 500 parts by mass, based on 100 parts by mass of the polymer (A).

[0094] <Anti-aging agent> The composition of the present invention may further contain an anti-aging agent such as an ultraviolet absorber, a light stabilizer, or an antioxidant. As ultraviolet absorber, for example, benzotriazole-based ultraviolet absorber, benzophenone-based ultraviolet absorber can be enumerated, and benzotriazole-based ultraviolet absorber is preferred.As benzotriazole-based ultraviolet absorber, for example, 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole, 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2H-benzotriazole-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, the reaction product of methyl 3-(3-(2H-benzotriazole-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate and polyethylene glycol, 2-(2H-benzotriazole-2-yl)-p-cresol can be enumerated.

[0095] Examples of the light stabilizer include hindered amine-based light stabilizers. Examples of the hindered amine-based light stabilizers include bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, decanedioic acid bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl)ester, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine).

[0096] Examples of the antioxidant include hindered phenol-based antioxidants, monophenol-based antioxidants, bisphenol-based antioxidants, polyphenol-based antioxidants, and phosphorus-based antioxidants.

[0097] The antioxidants can be used alone or in combination of two or more. In one embodiment, the content of the antioxidant in the composition of the present invention is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the polymer (A).

[0098] Dehydrating agent To further improve the storage stability, the composition of the present invention may contain a small amount of a dehydrating agent within a range that does not adversely affect the curing properties or flexibility. Examples of dehydrating agents include hydrolyzable organosilicon compounds such as methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, and vinyltrimethoxysilane; alkyl orthoformates such as methyl orthoformate and ethyl orthoformate; alkyl orthoacetates such as methyl orthoacetate and ethyl orthoacetate; and isocyanate compounds such as p-toluenesulfonyl isocyanate.

[0099] In one embodiment, the content of the dehydrating agent in the composition of the present invention is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the polymer component, from the viewpoints of the storage stability and curability of the curable composition. The polymer component may contain a polymer (F) in addition to the polymer (A).

[0100] <Tackifying resin> The composition of the present invention may further contain a tackifying resin. A cured product containing a tackifier resin has appropriate tackiness, and a pressure-sensitive adhesive layer with excellent shear adhesive strength can be obtained.

[0101] Examples of tackifying resins include rosin-based tackifying resins such as rosin ester-based resins, terpene-based tackifying resins such as terpene phenol-based resins, styrene-based tackifying resins, and alicyclic saturated hydrocarbon resins.

[0102] Rosin ester resins are resins obtained by esterifying rosin resins with alcohols. Examples of rosin resins include rosin resins, disproportionated rosin resins, and hydrogenated rosin resins, each of which contains a resin acid such as abietic acid as the main component, as well as dimers of resin acids such as abietic acid (polymerized rosin resins). Examples of alcohols include polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol.

[0103] A resin obtained by esterifying a rosin resin is a rosin ester resin, a resin obtained by esterifying a disproportionated rosin resin is a disproportionated rosin ester resin, a resin obtained by esterifying a hydrogenated rosin resin is a hydrogenated rosin ester resin, and a resin obtained by esterifying a polymerized rosin resin is a polymerized rosin ester resin.

[0104] The terpene phenol resin is a resin obtained by polymerizing terpene in the presence of phenol. Examples of disproportionated rosin ester resins include Superester A75 (10 or less), Superester A100 (10 or less), Superester A115 (20 or less), and Superester A125 (20 or less). Examples of polymerized rosin ester resins include Pencel D-125 (10-16), Pencel D-135 (10-16), and Pencel D-160 (10-16). These products are manufactured by Arakawa Chemical Industries, Ltd., and the numbers in parentheses indicate acid values ​​(mgKOH / g).

[0105] Examples of terpene-based tackifying resins include YS Polystar T30 (1 or less), YS Polystar T80 (1 or less), YS Polystar T130 (1 or less), Clearon 100 (1 or less), and Clearon 110 (1 or less). These products are manufactured by Yasuhara Chemical, and the numbers in parentheses are acid values ​​(mgKOH / g).

[0106] Examples of styrene-based tackifying resins include FMR-0150 (0.1 or less), FTR-6100 (0.1 or less), FTR-6110 (0.1 or less), FTR-6125 (0.1 or less), FTR-7100 (0.1 or less), FTR-8120 (0.1 or less), FTR-0100 (0.1 or less), FTR-2120 (0.1 or less), and FTR-2140 (0.1 or less). These products are manufactured by Mitsui Chemicals, and the values ​​in parentheses indicate the acid value (mgKOH / g). Another example is SX-100 (1 or less) manufactured by Yasuhara Chemical.

[0107] Examples of alicyclic saturated hydrocarbon resins include Alcon P-90, Alcon P-100, Alcon P-115, Alcon P-125, Alcon M-90, Alcon M-100, Alcon M-115, and Alcon M-135. These products are manufactured by Arakawa Chemical Industries, Ltd.

[0108] The tackifying resins can be used alone or in combination of two or more. Among these, from the viewpoint of the storage stability of the curable composition, a tackifier resin having an acid value of 1 mgKOH / g or less is preferred, and an acid value of 0.1 mgKOH / g or less is particularly preferred. By using a tackifier resin having an acid value of 0.1 mgKOH / g or less, a curable composition having particularly excellent storage stability can be obtained. The acid value refers to the number of milligrams of potassium hydroxide required to neutralize 1 g of tackifier resin, and can be measured according to JIS K0070.

[0109] The composition of the present invention contains the tackifier resin in an amount of preferably 1 to 900 parts by mass, more preferably 5 to 500 parts by mass, per 100 parts by mass of the polymer (A). In such an embodiment, the pressure-sensitive adhesive layer has appropriate tackiness and excellent adhesive strength to various adherends.

[0110] <Rheology control agent> The composition of the present invention may further contain a rheology control agent. The rheology control agent can improve the smoothness of the film surface. As the rheology control agent, acrylic, urea, urethane, amide, polyester, layered inorganic compound, and the like can be used. Among these, polyester-based rheology control agents, such as "BYK R606 (polyhydroxycarboxylic acid ester)" manufactured by BYK Japan, are preferred.

[0111] The composition of the present invention contains the rheology control agent in an amount of preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, per 100 parts by mass of the polymer (A). In this embodiment, a curable composition having excellent thixotropy and pseudoplasticity can be obtained.

[0112] [Two-component curable composition] A two-component curable composition according to another embodiment of the present invention comprises a first part containing a (meth)acrylic polymer (A), a salt compound (B), and a polymerization initiator, and a second part containing a reducing agent. In the present invention, the two-component curable composition refers to a combination of the first part and the second part, i.e., the composition before the first part and the second part are mixed.

[0113] <First agent> The two-component curable composition of the present invention can contain one or more polymers (A) in the first part. By containing the polymer (A) in the first part, a two-component curable composition with excellent adhesiveness can be obtained. The two-part curable composition of the present invention may contain one or more salt compounds (B) in the first part. By containing the salt compound (B) in the first part, a two-part curable composition with excellent storage stability can be obtained. In one embodiment, the content of the salt compound (B) in the two-component curable composition of the present invention is preferably 0.1 to 100 parts by mass, more preferably 1 to 50 parts by mass, based on 100 parts by mass of the polymer (A).

[0114] <Polymerization initiator> The two-component curable composition of the present invention may contain one or more polymerization initiators in the first part. The polymerization initiator is preferably a peroxide initiator, such as those described in the section on the production of polymer (A). In one embodiment, the content of the polymerization initiator in the two-component curable composition of the present invention is preferably 0.01 to 2,000 parts by mass, more preferably 0.1 to 1,000 parts by mass, based on 100 parts by mass of the polymer (A).

[0115] <Second agent> The two-part curable composition of the present invention may contain one or more reducing agents in the second part.

[0116] <Reducing agent> Any known reducing agent that reacts with the polymerization initiator to generate radicals can be used as the reducing agent, and examples thereof include tertiary amines, thiourea derivatives, and transition metal salts.

[0117] Examples of tertiary amines include triethylamine, tripropylamine, tributylamine, and N,N-dimethyl-p-toluidine.

[0118] Examples of thiourea derivatives include 2-mercaptobenzimidazole, methylthiourea, dibutylthiourea, tetramethylthiourea, and ethylenethiourea.

[0119] Examples of transition metal salts include cobalt naphthenate, copper naphthenate, cobalt octenate, copper acetylacetonate, vanadyl acetylacetonate, vanadium acetylacetonate, etc. Among these, transition metal salts are preferred in terms of reactivity, and vanadyl acetylacetonate is more preferred. In one embodiment, the content of the reducing agent in the two-component curable composition of the present invention is preferably 0.001 to 500 parts by mass, more preferably 0.01 to 100 parts by mass, based on 100 parts by mass of the polymer (A).

[0120] The two-component curable composition of the present invention may further contain an epoxy resin (C) and / or a (meth)acrylic monomer. The epoxy resin (C) and / or the (meth)acrylic monomer may be contained in both the first part and the second part, or each may be independently contained in one of them. The epoxy resin (C) and the (meth)acrylic monomer may be used alone, or two or more kinds may be used.

[0121] (Meth)acrylic monomers Examples of the (meth)acrylic monomer include: oxygen-containing (meth)acrylic monomers such as tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, methoxyethyl (meth)acrylate, and (3-ethyloxetan-3-yl)methyl (meth)acrylate; Nitrogen-containing (meth)acrylic monomers such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethyl (meth)acrylamide, and (meth)acryloylmorpholine; Sulfur-containing (meth)acrylic monomers such as 2-methylthioethyl (meth)acrylate; Monofunctional (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and isobornyl (meth)acrylate; pentaerythritol di(meth)acrylate; and (meth)acrylic acid esters such as polyfunctional (meth)acrylates such as acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, butyl di(meth)acrylate, and hexyl di(meth)acrylate.

[0122] In one embodiment, the content of the (meth)acrylic monomer in the two-component curable composition of the present invention is preferably 1 to 100,000 parts by mass, more preferably 10 to 10,000 parts by mass, based on 100 parts by mass of the polymer (A).

[0123] The two-part curable composition is stored by separating the first and second parts, with the first part containing at least a polymerization initiator and the second part containing at least a reducing agent. In this case, the two parts can be applied simultaneously or separately, brought into contact, and cured, allowing them to be used as a two-part curable composition.

[0124] [Uses of curable compositions and cured products] The composition of the present invention contains a polymer (A) and a salt compound (B) composed of an acid and a base that satisfy a predetermined pKa, and therefore can be cured under a desired thermal environment, and has excellent storage stability and mechanical properties. Furthermore, because the composition of the present invention has good crosslinkability, it can be used in applications where it is cured by crosslinking, or in applications where the elasticity of the cured product is utilized, etc. It is believed that in the composition, moisture present in the atmosphere or in the adherend to which the curable composition is applied causes, for example, hydrolysis of the group represented by formula (1) in polymer (A), and, when polymer (F) is used, the group represented by formula (1) in polymer (F), to form silanol groups, which then undergo dehydration condensation with each other to form siloxane bonds, thereby curing to form a cured product.

[0125] The composition of the present invention or a two-component curable composition obtained by mixing and stirring is suitable for use as a sealant, adhesive, hot melt adhesive, paint, or the like in construction and building material applications, automotive applications, and the like. Other examples include coating agents for covering the surfaces of inorganic materials (e.g., cement, mortar, metal, and glass), sheet-forming compositions (examples of sheets: breathable sheets, protective sheets, water-shielding sheets, vibration-damping sheets, transfer sheets, light-modulating sheets, antistatic sheets, conductive sheets, protective sheets, sound-insulating sheets, light-blocking sheets, decorative sheets, marking sheets, and flame-retardant sheets), film-forming compositions (examples of films: marking films, protective films, ink-fixing films, and laminate films), foam-forming compositions (examples of foams: rigid foams, flexible foams, semi-rigid foams, and flame-retardant foams), compositions for forming vibration-damping materials, sound-insulating materials, sound-proofing materials, sound-absorbing materials, artificial leather, artificial skin, synthetic leather, various industrial parts, daily necessities, and molded toiletry products, paint vehicles, primer resins, and various binders (e.g., ink binders, binders for magnetic recording media, binders for casting, binders for fired bodies, and binders for glass fiber sizing materials).

[0126] The cured product of the present invention can be obtained from the curable composition or two-component curable composition of the present invention. The curing conditions are not particularly limited, but in the case of a curable composition (e.g., a one-component curable composition), the composition of the present invention can be applied to a support and left for a predetermined period of time in an environment of 100 to 200°C, preferably 120 to 180°C, to allow the curing to proceed satisfactorily. In the case of a two-component curable composition, the composition of the present invention can be applied to a support in any ratio, thereby obtaining a cured product. [Example]

[0127] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. In the following descriptions of the examples and comparative examples, "parts" means "parts by mass" unless otherwise specified.

[0128] [Polymer evaluation method] The methods for evaluating the various physical properties of the polymer are described below. <Number average molecular weight (Mn) and weight average molecular weight (Mw)> The number average molecular weight (Mn) and weight average molecular weight (Mw) of each polymer were analyzed by gel permeation chromatography (GPC) and calculated in terms of polystyrene under the following conditions. Equipment: GPC-8220 (Tosoh) Column: G7000HXL / 7.8mmID x 1 GMHXL / 7.8mmID x 2 + G2500HXL / 7.8mm ID x 1 Medium: Tetrahydrofuran ·Flow rate: 1.0mL / min ·Concentration: 1.5mg / ml ·Injection volume: 300μL Column temperature: 40℃

[0129] <Glass transition temperature (Tg)> The glass transition temperature (Tg) of each polymer was measured by differential scanning calorimetry (DSC). Equipment: DSC7000X (Hitachi High-Tech Science) Temperature condition: -100℃ to 30℃ at 10℃ / min Sample container: Aluminum open cell Sample size: 5 mg

[0130] <Silicon element content> The silicon content of each polymer was measured by adding 7 mL of mixed acid containing hydrogen fluoride to 0.2 g of the polymer, wet ashing using a microwave decomposition device (Anthol Japan), adding ultrapure water to the ashed sample to make a constant volume of 50 mL, and then using an inductively coupled plasma atomic emission spectroscopy (ICP-AES). Equipment: ICPE-9000 (Shimadzu Corporation) High frequency power: 1.20kW Plasma gas: 10.00 L / min Auxiliary gas: 0.60L / min Carrier gas: 0.70 L / min Observation direction: Axial direction

[0131] [Manufacturing Example 1] A stainless steel flask equipped with a stirrer, nitrogen gas inlet, thermometer, and reflux condenser was charged with 70 parts n-butyl acrylate, 25 parts 2-ethylhexyl acrylate, and 5 parts acryloxymethyltrimethoxysilane. After nitrogen substitution, the mixture was heated to 70°C. Next, while maintaining the contents of the flask at 75°C, 4.5 parts 3-mercaptopropyltrimethoxysilane was added, followed by 0.05 parts 2,2'-azobisisobutyronitrile (AIBN) to initiate the reaction. Three hours after the start of the reaction, 0.05 parts AIBN was added. Six hours after the start of the reaction, volatile components were distilled off under reduced pressure at 110°C for 3 hours to obtain (meth)acrylic polymer (A-1). The silicon content of polymer (A-1) was 8,850 ppm, Mn was 8,000, Mw was 13,000, and Tg was -67°C.

[0132] [Manufacturing Examples 2 to 4] The same procedure as in Production Example 1 was carried out except that the raw material components used were changed as shown in Table 1, to obtain (meth)acrylic polymers (A-2), (A-3), and (cA-1).

[0133] [Table 1]

[0134] Example 1: Preparation of one-component curable composition 100 parts of (meth)acrylic polymer (A-1), 10 parts of DBU-o-phthalate salt (pKa(HO):DBU=12, o-phthalic acid=2.9) "U-CAT SA 810" (manufactured by San-Apro) as salt compound (B), 200 parts of bisphenol A epoxy resin "jER828" and 200 parts of "jER1001" (both manufactured by Mitsubishi Chemical) as epoxy resin (C), and 0.5 parts of phenolic antioxidant "ADEKA STAB AO-80" (manufactured by ADEKA) were added to a stainless steel flask and stirred for 10 minutes at 90°C. After cooling to room temperature, 10 parts of vinyltrimethoxysilane "KBM-1003" (manufactured by Shin-Etsu Chemical Co., Ltd.) as a dehydrating agent were added and mixed for 10 minutes to obtain a curable composition. The resulting curable composition was subjected to various evaluations.

[0135] [Examples 2 to 5, Comparative Examples 1 to 5] Curable compositions were obtained and various evaluations were carried out in the same manner as in Example 1, except that the blending compositions were changed as shown in Table 2. The evaluation methods will be described later. Example 6: Preparation of two-component curable composition 100 parts of (meth)acrylic polymer (A-1), 20 parts of "U-CAT SA 506," 400 parts of tetrahydrofurfuryl acrylate, and 20 parts of thermal polymerization initiator "Percumyl H-80" (manufactured by NOF Corp.) were placed in a stainless steel flask and stirred for 10 minutes to prepare Agent I. Next, 500 parts of tetrahydrofurfuryl acrylate and 2.5 parts of reducing agent "Vanadyl Acetate 50D" (manufactured by Shinko Chemical Industry Co., Ltd.) were placed in a separate stainless steel flask and stirred for 10 minutes to prepare Agent II. Various evaluations were performed on the resulting Agent I and on a mixture of Agents I and II.

[0136] [Examples 7 and 8, Comparative Examples 6 to 9] Agents I and II were prepared in the same manner as in Example 6, except that the blending compositions were changed as shown in Table 3. Various evaluations were carried out on the obtained agent I and on a mixture of agent I and agent II.

[0137] [Table 2]

[0138] [Table 3]

[0139] In Tables 2 and 3, "-" indicates that the curable composition was cured during preparation or did not cure and therefore could not be evaluated.

[0140] The meaning of the notation of each component in Tables 2 and 3 is as follows: U-CAT SA 810: DBU-o-phthalate [pKa(H2O):DBU = 12 (same below), o-phthalic acid = 2.9] (San-Apro) U-CAT SA 506: DBU-paratoluenesulfonate [pKa(H2O) = paratoluenesulfonic acid = 2.4] (San-Apro) U-CAT SA 603: DBU-formate [pKa(H2O):formic acid=3.8] (San-Apro) U-CAT SA 102: DBU-octylate [pKa(H2O):octylate=4.8] (San-Apro) jER828: Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical, epoxy equivalent: 184-194) jER1001: Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical, epoxy equivalent: 450-500) KBM-1003: Vinyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.) ADK STAB AO-80: Phenolic antioxidant (manufactured by ADEKA) THFA: Tetrahydrofurfuryl acrylate Percumyl H-80: Cumene hydroperoxide (NOF) Vanadyl acetylacetate 50D: Vanadyl acetylacetate (manufactured by Shinko Chemical Industry)

[0141] [Method for evaluating curable compositions] The methods for evaluating the various physical properties of the curable composition are described below. <Pot life of one-component curable composition> The curable compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were left in an environment at 23°C, and the number of days until a film was formed was measured. <Pot life of the first component in the two-component curable composition> The I agents prepared in Examples 6 to 8 and Comparative Examples 6 to 9 were left in a 23°C environment, and the time until a film was formed was measured.

[0142] <Curing time> Five grams of the curable compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were transferred to a metal container (33 mm diameter, 13 mm height). The metal container containing the curable composition was then left in an environment of 140°C, and the time until a coating was formed was measured.

[0143] <Shear adhesive strength, cohesive failure rate, shear adhesive strength change rate> The curable compositions obtained in the examples and comparative examples were applied to two test pieces made of stainless steel 304 (1 mm thick) in accordance with JIS-K6850:1999 (Testing method for tensile shear bond strength between adhesive and rigid adherend), and the pieces were laminated together so that the thickness of the curable composition layer was 0.2 mm. The one-component compositions shown in Table 2 were heated at 140°C for 1 hour, while the two-component curable compositions shown in Table 3 were not heated. The shear adhesive strength was measured in accordance with JIS K6850:1999 using a universal tensile tester AG-X (manufactured by Shimadzu Corporation) at a tensile speed of 50 mm / min and 23°C. The cohesive failure rate (the ratio of the cohesive failure area to the total adhesive area) was also measured. The rate of change in shear adhesive strength was calculated using the following formula for the two-component curable compositions shown in Table 3, by taking the shear adhesive strength of a test piece obtained without heating (shear adhesive strength before heating) and the shear adhesive strength after heating at 120°C for 1 hour (shear adhesive strength after heating). [(Shear adhesive strength after heating) - (Shear adhesive strength before heating)] ÷ (Shear adhesive strength before heating) × 100 The rate of change in shear adhesive strength is an index that indicates the degree to which the curing of the alkoxysilyl group is completed due to the heat of polymerization generated when the first and second components come into contact with each other, and a smaller rate of change means that there is less uncured component.

Claims

1. a (meth)acrylic polymer (A) having a group represented by formula (1) and containing 1,500 ppm or more of silicon element; A curable composition comprising a salt compound (B) composed of an acid having an acid dissociation constant (pKa) of less than 3.5 and a base having a pKa of 10 or more, the (meth)acrylic polymer (A) has a structural unit derived from a monomer (a2) represented by formula (a2-1), the salt compound (B) is a salt compound composed of an organic acid having a pKa of 1 or more and less than 3.5 and an organic base having a pKa of 10 or more and less than 15, The curable composition, wherein the organic base is 1,8-diazabicyclo[5.4.0]undecene-7 (DBU). Formula (1): -X-CH 2 -SiR 1 3 [In formula (1), R 1 are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group, and R 1 at least one of the groups is the alkoxy group or the hydroxyl group; X is —O—, —COO—, —S—, —N(R 2 )-,-CH(OH)-CH 2 —O—, —O—CO—NH—, or —N(R 2 )-CO-N(R 3 )-, and R 2 and R 3 is a hydrogen atom, a hydrocarbon group, or a halogenated hydrocarbon group, and R 2 and R 3 may be the same or different. 【Chemical 1】 [In formula (a2-1), R a represents a hydrogen atom or a methyl group, and R 1 has the same meaning as R 1 in formula (1)]

2. The curable composition according to claim 1, wherein the salt compound (B) is contained in an amount of 0.01 to 50 parts by mass per 100 parts by mass of the (meth)acrylic polymer (A).

3. The curable composition according to claim 1, wherein the (meth)acrylic polymer (A) has a group represented by formula (1) at least at a molecular chain terminal.

4. The curable composition according to claim 1, wherein the (meth)acrylic polymer (A) has a number average molecular weight (Mn) of 1,000 to 100,000.

5. The curable composition according to claim 1, comprising 1 to 1,000 parts by mass of the epoxy resin (C) relative to 100 parts by mass of the (meth)acrylic polymer (A).

6. A cured product obtained from the curable composition according to any one of claims 1 to 5.

7. A two-component curable composition comprising a first part containing the curable composition according to any one of claims 1 to 5 and a polymerization initiator, and a second part containing a reducing agent.

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