Curable composition and cured product

Abstract

To provide a curable composition giving a cured product which is easy to stretch with small force and has improved elongation.SOLUTION: A curable composition according to one embodiment of the present invention contains a component A: a (meth)acrylic polymer having a silyl group, a component B: an epoxy compound, a component C: a polyamine, and a component D: a curing catalyst. The components A and B satisfy specific conditions.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable composition and a cured product.

Background Art

[0002] Polymer molecules having silyl groups form siloxane bonds with other polymer molecules by hydrolysis of the silyl groups. A rubbery cured product is obtained by this crosslinking reaction. Curable compositions containing such polymer molecules are used in sealing materials, adhesives, paints, etc. (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There has been room for improvement in the modulus and elongation of the cured product in the curable compositions disclosed in the prior art such as Patent Document 1.

[0005] One aspect of the present invention aims to provide a curable composition that gives a cured product that is easily stretchable with a small force and has improved elongation.

Means for Solving the Problems

[0006] To solve the above problems, a curable composition according to one aspect of the present invention contains the following components A to D: Component A: A (meth)acrylic polymer having a silyl group; Component B: An epoxy compound; Component C: A curing catalyst; Component D: A polyvalent amine; Here, the above Component A is It has an XY diblock structure or an XYX triblock structure having an X block and a Y block in the molecule, The repeating unit derived from the silyl group-containing (meth)acrylate monomer contained in the X block is more than 2.0 on average, The repeating unit derived from the silyl group-containing (meth)acrylate monomer contained in the Y block is 0% by weight or more and less than 5% by weight based on the weight of all the repeating units contained in the Y block, The molecular weight distribution (Mw / Mn) is 1.8 or less, Component B above, On average, per molecule, has 1.0 or fewer epoxy groups.

Advantages of the Invention

[0007] According to one aspect of the present invention, there is provided a curable composition that is easily stretchable with a small force and gives a cured product with improved stretchability.

Modes for Carrying Out the Invention

[0008] Hereinafter, an example of an embodiment of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications may be made within the scope shown in the claims. Embodiments in which technical means described in different embodiments are combined are also included in the technical scope of the present invention.

[0009] Unless otherwise specified in this specification, "A~B" representing a numerical range means "A or more and B or less". In this specification, "(meth)acryl" means "acryl and / or methacryl". Unless otherwise specified in this specification, "silyl group" means "hydrolyzable silyl group". In one embodiment, the silyl group is an alkoxysilyl group.

[0010] 〔1. Components of the curable composition〕 The curable composition according to one aspect of the present invention contains Component A: a (meth)acrylic polymer having a silyl group, Component B: a polyoxyalkylene polymer having a silyl group, Component C: a polyvalent amine, and Component D: a curing catalyst. The curable composition may contain, as optional components, Component E: a drying oil and Component F: a metal salt of a higher fatty acid that is liquid or alcohol-soluble. Each of these components may contain only one type or two or more types.

[0011] [1.1. Component A: (Meth)acrylic polymer having a silyl group] Component A is a (meth)acrylic polymer having a silyl group. Component A has a silyl group derived from a silyl group-containing (meth)acrylate monomer. Component A has an X block with a high frequency of silyl group appearance and a Y block with a low frequency of silyl group appearance. Component A can be polymerized, for example, by changing the monomer composition during polymerization.

[0012] [1.1.1. Structure of Component A] Component A has an X block and a Y block and contains an XY diblock structure or an XYX triblock structure in the molecule. The structure of the whole molecule of Component A is not particularly limited as long as it contains an XY diblock structure or an XYX triblock structure, and may be, for example, an XYXY tetrablock structure.

[0013] Here, the "XYX triblock structure" means the "ABA triblock structure" generally referred to among those skilled in the art. The ratio of X / Y in Component A is preferably (5 / 95) to (60 / 40), more preferably (15 / 85) to (40 / 60).

[0014] In one embodiment, the molecule of Component A has an XY diblock structure. In the molecule having an XY diblock structure, the X block can be a region of 40% or less, 30% or less, or 25% or less from one end of the molecule (assuming that all repeating units contained in the molecule are 100%). Here, the X block is the block on the side where the silyl groups are relatively more distributed.

[0015] In one embodiment, the molecule of component A has an XYX triblock structure. In the molecule with the XYX triblock structure, the X block may be a region of 40% or less, 30% or less, or 25% or less from the end of the molecule (assuming 100% of all repeating units contained in the molecule). Here, the X block is the block located at both ends of the molecule.

[0016] Component A has repeating units derived from a silyl group-containing (meth)acrylate monomer. The repeating units derived from the silyl group-containing (meth)acrylate monomer are relatively more contained in the X block. The average number of repeating units derived from the silyl group-containing (meth)acrylate monomer contained in the X block is more than 2.0. When component A has two or more X blocks in one molecule, the total number of repeating units derived from the silyl group-containing (meth)acrylate monomer contained in the plurality of X blocks is more than 2.0 on average. On the other hand, the repeating units derived from the silyl group-containing (meth)acrylate monomer contained in the Y block are 0 wt% or more and less than 5 wt% based on the weight of all repeating units contained in the Y block.

[0017] The average number of repeating units derived from the silyl group-containing (meth)acrylate monomer contained in the X block is more than 2.0, preferably 2.1 or more, more preferably 2.2 or more, still more preferably 2.3 or more, and particularly preferably 2.5 or more. Similarly, the repeating units derived from the silyl group-containing (meth)acrylate monomer contained in the X block are preferably 0.5 wt% or more, more preferably 2.0 wt% or more, and still more preferably 3.0 wt% or more based on the weight of all repeating units contained in the X block. The upper limit of the repeating units derived from the silyl group-containing (meth)acrylate monomer contained in the X block is preferably 90 wt% or less, more preferably 60 wt% or less, and still more preferably 30 wt% or less.

[0018] The upper limit of the repeating unit derived from the silyl group-containing (meth)acrylate monomer contained in the Y block is less than 5% by weight, preferably 4% by weight or less, more preferably 3% by weight or less, still more preferably 2% by weight or less, and particularly preferably 1% by weight or less, based on the weight of all the repeating units contained in the Y block. The lower limit of the repeating unit derived from the silyl group-containing (meth)acrylate monomer contained in the Y block is preferably 0% by weight or more, more preferably more than 0% by weight, based on the weight of all the repeating units contained in the Y block.

[0019] The number of silyl groups introduced into Component A is, on average, more than 2.0, preferably 2.2 or more, more preferably 2.6 or more, still more preferably 3.0 or more, and particularly preferably 3.4 or more per molecule as a whole. The upper limit of the number of silyl groups introduced into the (meth)acrylic polymer is preferably 10.0 or less, more preferably 8.0 or less, still more preferably 6.0 or less, and particularly preferably 5.0 or less. When the number of silyl groups is within the above range, a curable composition and a cured product having good physical properties can be obtained.

[0020] Specific examples of the silyl group-containing (meth)acrylate monomer include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

[0021] Component A may contain a repeating unit derived from a (meth)acrylic monomer having a long-chain side chain. In the present specification, the "(meth)acrylic monomer having a long-chain side chain" is a monomer represented by the formula: CH2=C(R 1 )COOR 2 . In the formula, R 1 is a hydrogen atom or a methyl group. R 2 is a group having 9 or more carbon atoms.

[0022] The content of the repeating unit derived from a (meth)acrylic monomer having a long side chain is preferably 1% by weight or more based on all the constituent units contained in Component A. Component A containing such a repeating unit may have improved compatibility with a polyoxyalkylene polymer or improved physical properties of the resulting cured product. The upper limit of the content of the repeating unit derived from a (meth)acrylic monomer having a long side chain is preferably 5% by weight or less, more preferably 3% by weight or less. If the content is within the above range, the production cost of Component A can be prevented from soaring extremely.

[0023] Examples of the (meth)acrylic monomer having a long side chain include nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, docosyl (meth)acrylate, oleyl (meth)acrylate, linoleyl (meth)acrylate, and isobornyl (meth)acrylate.

[0024] Among the above-mentioned monomers, one or more selected from octadecyl (meth)acrylate, oleyl (meth)acrylate, and linoleyl (meth)acrylate are preferable. These monomers are liquid at room temperature and have the advantage of high polymerization stability. Further, by blending these monomers, a (meth)acrylic polymer having high compatibility with a polyoxyalkylene polymer can be obtained.

[0025] In the present specification, the "(meth)acrylic monomer having a non-long side chain" means that in the above formula, R 2represents a monomer having a group with 8 or fewer carbon atoms. Examples of such monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, isopropoxyethyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, glycidyl (meth)acrylate, 1-ethylcyclopentyl ether (meth)acrylate, and dimethylaminoethyl (meth)acrylate.

[0026] Among the above-mentioned monomers, one or more selected from methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred. These monomers have low procurement costs and are suitable for the purpose of reducing the manufacturing cost of Component A.

[0027] Furthermore, from the viewpoint of the glass transition temperature, one or more selected from n-butyl acrylate and 2-ethylhexyl acrylate are preferred. Component A obtained from these monomers has a low glass transition temperature and the viscosity of the polymer is low. Therefore, a curable composition that is easy to use in a low-temperature environment can be obtained.

[0028] Component A may have a repeating unit derived from a monomer other than the (meth)acrylate monomer. In Component A, the proportion of the repeating unit derived from the (meth)acrylate monomer preferably occupies 50% by weight or more, more preferably 70% by weight or more, and even more preferably 90% by weight or more of the total weight of Component A.

[0029] [1.1.2. Silyl group possessed by Component A] The silyl group possessed by Component A may be derived from a silyl group-containing (meth)acrylate monomer. In one embodiment, the silyl group is represented by the following general formula (1). -[Si(R 3 ) 2-b (Y) b O] m -Si(R 4 ) 3-a (Y) a ···(1)

[0030] In formula (1), R 3 and R 4 are each independently an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a methoxymethyl group, or a triorganosiloxy group represented by (R’)3SiO-. R’ is a monovalent hydrocarbon group having 1 to 20 carbon atoms. The three R’s present may be the same or different. When two or more R 3 or R 4 are present, they may be the same or different. Y represents a hydroxyl group or a hydrolyzable group. Examples of the hydrolyzable group include an alkoxy group, an acetoxy group, and an oxime group. In one embodiment, Y is a hydroxyl group, a methoxy group, an ethoxy group, or an isopropoxy group. When a plurality of X’s are contained in one silyl group, they may be the same or different. When a plurality of silyl groups are contained in one molecule of Component A, Y may be different for each silyl group. a is 0, 1, 2, or 3. b is 0, 1, or 2. m is an integer from 0 to 19. However, the relationship a + mb ≧ 1 is satisfied.

[0031] The specific structure of the silyl group-containing (meth)acrylate monomer is not particularly limited. As an example, a monomer represented by the following general formula can be mentioned. H2C=C(R 5 )C(=O)-O-(CH2) m -SiR 6n (OR 7 ) 3-n

[0032] In the formula, R 5 is hydrogen or a methyl group. R 6 and R 7 are one or more selected from the group consisting of hydrogen, a methyl group, and an ethyl group. R 6 and / or R 7 When there are a plurality of them, they may be the same or different. m is an integer from 0 to 10. n is an integer from 0 to 2.

[0033] Specific examples of the silyl group-containing (meth)acrylic acid ester monomer include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

[0034] [1.1.3. Physical properties of Component A] In one embodiment, the lower limit of the number average molecular weight of Component A is preferably 2,000 or more, more preferably 10,000 or more, and even more preferably 15,000 or more. The upper limit of the number average molecular weight of Component A is preferably 50,000 or less, more preferably 30,000 or less, and even more preferably 20,000 or less. If the number average molecular weight of Component A is within the above range, the viscosity of the curable composition will not become too high, and sufficient workability can be ensured.

[0035] In one embodiment, the molecular weight distribution of Component A is 1.8 or less, preferably 1.5 or less, 1.4 or less, 1.3 or less, or 1.2 or less. If the molecular weight distribution is within the above range, the viscosity of the polymer tends to decrease and the workability tends to improve. The molecular weight distribution is a value given by "weight average molecular weight ÷ number average molecular weight".

[0036] The weight-average molecular weight and the number-average molecular weight are measured by gel permeation chromatography (GPC). For GPC measurement, chloroform is used as the mobile phase and a polystyrene gel column is used as the stationary phase. The molecular weight obtained by the measurement is the molecular weight in terms of standard polystyrene.

[0037] [1.1.4. Method for Producing Component A] The polymerization method of Component A is not particularly limited, and known polymerization methods can be used (radical polymerization method, cationic polymerization method, anionic polymerization method, etc.). A polymerization method called SGO (Solid Grade Oligomer; high-temperature continuous bulk polymerization) is preferable because Component A can be obtained with little use of a polymerization solvent, a polymerization initiator, a chain transfer agent, etc. The living polymerization method is preferable because a functional group can be introduced near the terminal of the polymer molecule and Component A with a narrow molecular weight distribution can be synthesized. Examples of the living polymerization method include living radical polymerization method, living cationic polymerization method, and living anionic polymerization method. Among them, the living radical polymerization method is suitable for the polymerization of (meth)acrylic monomers. Examples of the living radical polymerization method include the following. · Atom Transfer Radical Polymerization (ATRP) (see J. Am. Chem. Soc. 1995, 117, 5614; Macromolecules. 1995, 28, 1721) · Single Electron Transfer Polymerization (SET-LRP) (see J. Am. Chem. Soc. 2006, 128, 14156; JPSChem 2007, 45, 1607) · Reversible Chain Transfer Catalyzed Polymerization (RTCP) (see "Living Radical Polymerization Controlled by Organocatalysts", Polymer Journal 68, 223-231 (2011); JP-A 2014-111798) · Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT polymerization) · Nitroxyl radical method (NMP method) · Polymerization method using an organic tellurium compound (TERP method) · Polymerization method using an organic antimony compound (SBRP method) · Polymerization method using an organic bismuth compound (BIRP method) · Iodine transfer polymerization method

[0038] As an example of a method for introducing a silyl group into component A, the method described in JP-A-2018-162394 can be mentioned. The method disclosed in this document introduces a silyl group into component A by copolymerizing a (meth)acrylic acid ester monomer and a silyl group-containing (meth)acrylic acid ester monomer. More specifically, by controlling the input amount of the silyl group-containing (meth)acrylic acid ester monomer according to the progress stage of living polymerization, a silyl group is introduced near the terminal of the component A molecule. Component A obtained by these methods can have a silyl group locally at the terminal or near the terminal of the molecule.

[0039] [1.2. Component B: Epoxy compound] Component B is an epoxy compound. The number of epoxy groups contained in component B is 1.0 or less on average per molecule.

[0040] Generally, a monoepoxide is used as component B. The number of epoxy groups contained in a commercially available monoepoxide is regarded as 1 on average per molecule unless there are special circumstances. When component B is synthesized by itself, etc., due to by-products or the introduction rate of epoxy groups, the number of epoxy groups contained in component B may be less than 1.0 on average per molecule. The lower limit of the number of epoxy groups contained in component B can be 0.7 or more, 0.8 or more, or 0.9 or more on average per molecule.

[0041] In one embodiment, component B is a monoepoxide. Examples of monoepoxides include the following. · Hydrocarbon oxides with 2 to 24 carbon atoms: ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, α-olefin oxides with 5 to 24 carbon atoms, styrene oxide, etc. · Glycidyl ethers of substituted or unsubstituted hydrocarbons with 2 to 19 carbon atoms: 2-phenoxyisopropyl glycidyl ether, n-butyl glycidyl ether, allyl glycidyl ether, 2-ethyl-hexyl glycidyl ether, 2-methyloctyl glycidyl ether, lauryl alcohol (EO) 15 Glycidyl ether, C12, C13 mixed alcohol glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, 2-phenylphenol glycidyl ether, phenol (EO)5 glycidyl ether p-sec-butylphenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, etc. · Glycidyl esters of monocarboxylic acids with 3 to 30 carbon atoms: glycidyl acrylate, glycidyl methacrylate, etc. · Epihalohydrins: epichlorohydrin, epibromohydrin, etc. · Hydroxyl group-containing oxides: glycidol, etc. · Epoxysilane compounds: 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 4-oxiranylbutyltrimethoxysilane, 8-oxiranyloctyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. · Monofunctional alicyclic epoxy compounds: 4-vinyl epoxycyclohexane, dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, vinyl cyclohexene monoepoxide, etc.

[0042] Component B may be a commercially available product. Examples of such products include Denacol EX-121, EX-141, EX-142-IM, EX-145, EX-146, EX-146P, EX-171, EX-192, EX-731 (all of the above are from Nagase ChemteX Corporation); YED111N, 111AN, 188 (all of the above are from Mitsubishi Chemical Corporation).

[0043] [1.3. Component C: Polyamine] Component C is a polyamine. A polyamine is a compound having a total of two or more amino groups or substituted amino groups. Examples of Component C include compounds having two amino groups or substituted amino groups (ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, etc.); compounds having three amino groups or substituted amino groups (diethylenetriamine, pentamethyldiethylenetriamine, trimer of ethylenemine, etc.); compounds having four or more amino groups or substituted amino groups (triethylenetetramine, N,N'-bis(3-aminopropyl)butane-1,4-diamine, tetramer of ethylenimine, etc.). Component C may be a polymer having a large number of amino groups or substituted amino groups.

[0044] [1.4. Component D: Curing Catalyst] Examples of the curing catalyst include tin-based curing catalysts. Specific examples of the tin-based curing catalysts include dialkyltin carboxylates (dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diethylhexanoate, dibutyltin dioctate, dibutyltin dimethyl maleate, dibutyltin diethyl maleate, dibutyltin dibutyl maleate, dibutyltin diisooctyl maleate, dibutyltin ditridecyl maleate, dibutyltin dibenzyl maleate, dibutyltin maleate, dioctyltin diacetate, dioctyltin distearate, dioctyltin dilaurate, dioctyltin diethyl maleate, dioctyltin diisooctyl maleate, etc.); dialkyltin oxides (dibutyltin oxide, dioctyltin oxide, a mixture of dibutyltin oxide and phthalic acid ester, etc.); reaction products of tetravalent tin compounds (dibutyltin oxide, dibutyltin diacetate, etc.) and silyl group-containing low molecular weight silicon compounds (tetraethoxysilane, methyltriethoxysilane, diphenyldimethoxysilane, phenyltrimethoxysilane, etc.); divalent tin compounds (tin octylate, tin naphthenate, tin stearate, etc.); monoalkyltins (monobutyltin compounds (monobutyltin trisoctoate, monobutyltin triisopropoxide, etc.), monooctyltin compounds, etc.); reaction products or mixtures of amine compounds and organotin compounds (reaction products or mixtures of laurylamine and tin octylate, etc.); chelate compounds (dibutyltin bisacetylacetonate, dioctyltin bisacetylcetonate, dibutyltin bisethylacetonate, dioctyltin bisethylacetonate, etc.); tin alcoholates (dibutyltin dimethylate, dibutyltin diethylate, dioctyltin dimethylate, dioctyltin diethylate, etc.).

[0045] Among these, chelate compounds (such as dibutyltin bisacetylacetonate) and tin alcoholates are preferably highly active as silanol condensation catalysts. Also, dibutyltin dilaurate is preferably less colored, inexpensive, and easily available even when added to the curable composition.

[0046] [1.5. Component E: Drying Oil] Component E is a drying oil. A drying oil is a fatty oil that has the property of being oxidized and solidified upon contact with air. By incorporating Component E, the surface tack of the cured product can be reduced.

[0047] Generally, Component E has a high degree of unsaturation. In one embodiment, the iodine value of Component E is 130 or more. Examples of Component E include tung oil, safflower oil, linseed oil, walnut oil, perilla oil, sesame oil, sunflower oil, poppy oil, and fish oil.

[0048] [1.6. Component F: Metal salt of a higher fatty acid that is liquid or alcohol-soluble] Component F is a metal salt of a higher fatty acid that is liquid or alcohol-soluble. By incorporating Component F, the surface tack of the cured product can be reduced.

[0049] The reason why Component F is liquid or alcohol-soluble is a requirement in the manufacturing process. That is, if the metal salt of the higher fatty acid is liquid, its miscibility with the curable composition is good, whereas if it is solid, its miscibility is poor. Even if the solid metal salt of the higher fatty acid is dissolved in a solvent and mixed, since the curable composition is moisture-curable, water cannot be used as a solvent. Instead, alcohol can be preferably used as a solvent. Since only a small amount of alcohol is required to dissolve Component F, using alcohol as a solvent also has the advantage of reducing the influence of the solvent on the curable composition.

[0050] The metal constituting Component F is not particularly limited and may be one type or two or more types. In one embodiment, the metal is an alkali metal or an alkaline earth metal. In one embodiment, the metal is one or more selected from the group consisting of magnesium, calcium, sodium, and potassium. Examples of other metals include lithium, zinc, manganese, aluminum, manganese, cobalt, zirconium, nickel, and bismuth.

[0051] The higher fatty acid constituting component F is not particularly limited and may be one type or two or more types. The lower limit of the number of carbon atoms of the higher fatty acid can be 6 or more, 8 or more, 10 or more, or 12 or more. The upper limit of the number of carbon atoms of the higher fatty acid can be 40 or less or 30 or less. The carboxyl group of the higher fatty acid is usually 1 per molecule. Examples of the higher fatty acid include 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, palmitoleic acid, oleic acid, elaidic acid, ricinoleic acid, eicosenoic acid, erucic acid, linoleic acid, linolenic acid, punica acid, and stearidonic acid.

[0052] Specific examples of component F include potassium 2-ethylhexylcarboxylate. When component F is alcohol-soluble, the alcohol used as the solvent can be appropriately selected by those skilled in the art according to the characteristics of component F.

[0053] [1.7. Other Components] The curable composition may contain various additives in addition to the components described above. By containing these additives, various physical properties of the curable composition and the cured product can be adjusted. Examples of the additives are as follows. These additives may be used alone or in combination of two or more.

[0054] (Adhesion Promoter) The curable composition may contain an adhesion promoter. By adding an adhesion promoter, the risk of the sealing material peeling from an adherend such as a siding board can be reduced (this peeling occurs due to fluctuations in the joint width or the like caused by external force). Also, in some cases, the need to use a primer to improve adhesion may be eliminated. In this case, simplification of the construction work is expected.

[0055] Examples of the adhesion promoter include silane coupling agents. Specific examples of silane coupling agents include isocyanate group-containing silanes (γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, etc.); amino group-containing silanes (γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldiethoxysilane, γ-ureidopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, etc.); mercapto group-containing silanes (γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, etc.); carboxysilanes (β-carboxyethyltriethoxysilane, β-carboxyethylphenylbis(2-methoxyethoxy)silane, N-(β-carboxymethyl)aminoethyl-γ-aminopropyltrimethoxysilane, etc.); vinyl-type unsaturated group-containing silanes (vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyltriethoxysilane, etc.); halogen-containing silanes (γ-chloropropyltrimethoxysilane, etc.); isocyanurate silanes (tris(trimethoxysilyl)isocyanurate, etc.).In addition, amino-modified silyl polymers, silylated amino polymers, unsaturated amino-silane complexes, phenylamino long-chain alkylsilanes, aminosilylated silicones, silylated polyesters, etc., which are derivatives obtained by modifying silane coupling agents, can also be used as silane coupling agents.

[0056] When the contents of Component A and Component B are 100 parts by weight, the content of the adhesion-imparting agent is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight.

[0057] (Filler) The curable composition may contain a filler. Examples of the filler include wood powder; reinforcing fillers (pulp, cotton chips, asbestos, mica, walnut shell powder, rice husk powder, graphite, clay, silica (fumed silica, precipitated silica, crystalline silica, fused silica, dolomite, anhydrous silicic acid, hydrous silicic acid, etc.), carbon black, etc.); fillers (heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, red iron oxide, aluminum fine powder, flint powder, zinc oxide, activated zinc white, zinc powder, zinc carbonate, shirasu balloon, etc.); fibrous fillers (asbestos, glass fiber and glass filament, carbon fiber, Kevlar fiber, polyethylene fiber, etc.).

[0058] When the total content of Component A and Component B is 100 parts by weight, the content of the filler is preferably 5 to 5000 parts by weight, more preferably 10 to 2500 parts by weight, and particularly preferably 15 to 1500 parts by weight.

[0059] (Physical property modifier) The curable composition may contain a physical property modifier for adjusting the tensile properties of the cured product. By using the physical property modifier, the hardness of the cured product can be increased, or conversely, the hardness of the cured product can be decreased and the elongation can be increased.

[0060] Examples of the physical property adjuster include alkylalkoxysilanes (such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, etc.); alkylisopropenoxysilanes (such as dimethyldiisopropenoxysilane, methyltriisopropenoxysilane, etc.); alkoxysilanes having a functional group (such as vinyldimethylmethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, etc.); silicone varnishes; polysiloxanes.

[0061] When the total content of component A and component B is 100 parts by weight, the content of the physical property adjuster is preferably 0.1 to 80 parts by weight, and more preferably 0.1 to 50 parts by weight.

[0062] (Thixotropic agent (anti-dripping agent)) The curable composition may contain a thixotropic agent (anti-dripping agent) in order to prevent dripping and improve workability.

[0063] Examples of the thixotropic agent include polyamide waxes; hydrogenated castor oil derivatives; metal soaps not contained in the above-mentioned component F (such as calcium stearate, aluminum stearate, barium stearate, etc.).

[0064] When the total content of component A and component B is 100 parts by weight, the content of the thixotropic agent is preferably 0.1 to 50 parts by weight, and more preferably 0.2 to 25 parts by weight.

[0065] (Photocurable substance) The curable composition may contain a photocurable substance. A photocurable substance is a substance that undergoes a chemical change in a short time under the action of light and causes a physical property change (such as curing). By containing a photocurable substance, the adhesiveness (residual tack) of the cured product surface can be reduced. A typical photocurable substance can be cured, for example, by standing at room temperature for one day at a sunlit position indoors (such as near a window). Many photocurable substances are known, such as organic monomers, oligomers, resins, and compositions containing these, and the types thereof are not particularly limited. Examples of photocurable substances include unsaturated acrylic compounds, vinyl polycinnamates, and azide resins.

[0066] Specific examples of unsaturated acrylic compounds include (meth)acrylic acid esters of low molecular weight alcohols (such as ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, neopentyl alcohol, etc.); (meth)acrylic acid esters of alcohols modified with acids (such as bisphenol A, isocyanuric acid) or low molecular weight alcohols with ethylene oxide, propylene oxide, etc.; (meth)acrylic acid esters (such as polyether polyols having a polyether main chain and a hydroxyl group at the end, polymer polyols obtained by radical polymerization of vinyl monomers in polyols having a polyether main chain, polyester polyols having a polyester main chain and a hydroxyl group at the end, polyols having a vinyl-based or (meth)acrylic-based copolymer main chain and a hydroxyl group in the main chain, etc.); epoxy acrylate-based oligomers obtained by reacting epoxy resins (such as bisphenol A type, novolac type, etc.) with (meth)acrylic acid; urethane acrylate-based oligomers having a urethane bond and a (meth)acrylic group in the molecular chain obtained by reacting polyols, polyisocyanates, hydroxyl group-containing (meth)acrylates, etc.

[0067] When the total content of component A and component B is 100 parts by weight, the content of the photocurable substance is preferably 0.01 to 30 parts by weight.

[0068] (Antioxidants and light stabilizers) The curable composition may contain an antioxidant and / or a light stabilizer. Various antioxidants and light stabilizers are known. For example, substances described in [Kenichi Saruwatari et al., "Antioxidant Handbook", Taiseisha, 1976] and [Yoshijiro Oze, ed., "Deterioration and Stabilization of Polymer Materials", CMC, 1990, pages 235-242] can be mentioned.

[0069] Examples of antioxidants include thioether antioxidants such as AdekaStab PEP-36 and AdekaStab AO-23 (all of the above are manufactured by ADEKA CORPORATION); phosphorus antioxidants such as Irgafos 38, Irgafos 168, and Irgafos P-EPQ (all of the above are manufactured by Ciba Specialty Chemicals); and hindered phenol antioxidants. Among those described above, hindered phenol antioxidants are preferred.

[0070] Specific examples of the hindered phenol-based antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, mono(or di or tri)(α-methylbenzyl)phenol, 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 2,2'-methylenebis(4-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 2,5-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, triethylene glycol-bis-[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2'-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis(3,5-di-t-butyl-4-hydroxybenzylphosphonic acid ethyl)calcium, tris-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 2,4-bis[(octylthio)methyl]o-cresol, N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine, tris(2,4-di-t-butylphenyl)phosphite, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5 - Di - t - butyl - 2 - hydroxyphenyl) benzotriazole, 2 - (3 - t - butyl - 5 - methyl - 2 - hydroxyphenyl) - 5 - chlorobenzotriazole, 2 - (3,5 - di - t - butyl - 2 - hydroxyphenyl) - 5 - chlorobenzotriazole, 2 - (3,5 - di - t - amyl - 2 - hydroxyphenyl) benzotriazole, 2 - (2’ - hydroxy - 5’ - t - octylphenyl) - benzotriazole, methyl - 3 - [3 - t - butyl - 5 - (2H - benzotriazole - 2 - yl) - 4 - hydroxyphenyl] propionate - polyethylene glycol (molecular weight about 300) condensate, hydroxyphenylbenzotriazole derivative, 2 - (3,5 - di - t - butyl - 4 - hydroxybenzyl) - 2 - n - butylmalonic acid bis(1,2,2,6,6 - pentamethyl - 4 - piperidyl), 2,4 - di - t - butylphenyl - 3,5 - di - t - butyl - 4 - hydroxybenzoate may be mentioned.,

[0071] Examples of commercially available antioxidants include Nocrack 200, Nocrack M - 17, Nocrack SP, Nocrack SP - N, Nocrack NS - 5, Nocrack NS - 6, Nocrack NS - 30, Nocrack 300, Nocrack NS - 7, Nocrack DAH (all of the above are manufactured by Ouchi Shinko Chemical Industry Co., Ltd.); Adeka Stab AO - 30, Adeka Stab AO - 40, Adeka Stab AO - 50, Adeka Stab AO - 60, Adeka Stab AO - 616, Adeka Stab AO - 635, Adeka Stab AO - 658, Adeka Stab AO - 80, Adeka Stab AO - 15, Adeka Stab AO - 18, Adeka Stab 328, Adeka Stab AO - 37 (all of the above are manufactured by Adeka Corporation); Irganox - 245, Irganox - 259, Irganox - 565, Irganox - 1010, Irganox - 1024, Irganox - 1035, Irganox - 1076, Irganox - 1081, Irganox - 1098, Irganox - 1222, Irganox - 1330, Irganox - 1425WL (all of the above are manufactured by Ciba Specialty Chemicals); Sumilizer GM, Sumilizer GA - 80, Sumilizer GS (all of the above are manufactured by Sumitomo Chemical Co., Ltd.).

[0072] Examples of the light stabilizer include ultraviolet absorbers (benzotriazole compounds such as Tinuvin P, Tinuvin 234, Tinuvin 320, Tinuvin 326, Tinuvin 327, Tinuvin 329, Tinuvin 213 (all of the above are from Ciba Specialty Chemicals)); triazine-based light stabilizers such as Tinuvin 1577; benzophenone compounds such as Chimassorb 81; benzoate compounds such as Tinuvin 120 (Ciba Specialty Chemicals); and hindered amine compounds). Among the above, hindered amine compounds are preferred.

[0073] Specific examples of the hindered amine compounds include dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}], N,N'-bis(3-aminopropyl)ethylenediamine-2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine condensate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, and bis(2,2,6,6-tetramethyl-4-piperidinyl) succinate ester.

[0074] Examples of commercially available light stabilizers include Tinuvin 622LD, Tinuvin 144, Chimassorb 944LD, Chimassorb 119FL; (all of the above are from Ciba Specialty Chemicals), AdekaStab LA-52, AdekaStab LA-57, AdekaStab LA-62, AdekaStab LA-67, AdekaStab LA-63, AdekaStab LA-68, AdekaStab LA-82, AdekaStab LA-87 (all of the above are from ADEKA Corporation); Sanol LS-770, Sanol LS-765, Sanol LS-292, Sanol LS-2626, Sanol LS-1114, Sanol LS-744, Sanol LS-440 (all of the above are from Ciba Specialty Chemicals).

[0075] The antioxidant and the light stabilizer may be used in combination. By using them in combination, the respective effects may be further improved, and the heat resistance, weather resistance, etc. of the cured product may be improved. For example, in order to improve the weather resistance, an ultraviolet absorber and a hindered amine compound (HALS) can be combined. This combination can further improve the effects of the respective agents and is preferable.

[0076] When the total content of Component A and Component B is 100 parts by weight, the content of the antioxidant and / or the light stabilizer is preferably 0.1 to 20 parts by weight respectively.

[0077] [2. Composition of the curable composition] In the curable composition, the lower limit of the weight ratio of Component A / Component B is preferably 50 / 50 or more, more preferably 60 / 40 or more, and even more preferably 70 / 30 or more. The upper limit of the weight ratio of Component A / Component B is preferably 99 / 1 or less, more preferably 95 / 5 or less, and even more preferably 90 / 10 or less. If each component is blended within the above range, a cured product with a large elongation and easy elongation with a small force tends to be obtained.

[0078] In the curable composition, when the total content of component A and component B is 100 parts by weight, the lower limit of the content of component C is preferably 0.01 part by weight or more, more preferably 0.05 part by weight or more, still more preferably 0.1 part by weight or more, and particularly preferably 0.5 part by weight or more. When the total content of component A and component B is 100 parts by weight, the upper limit of the content of component C is preferably 10 parts by weight or less, more preferably 8 parts by weight or less, and still more preferably 5 parts by weight or less.

[0079] In the curable composition, when the total content of component A and component B is 100 parts by weight, the lower limit of the content of component D is preferably 0.1 part by weight or more, and more preferably 0.5 part by weight or more. When the total content of component A and component B is 100 parts by weight, the upper limit of the content of component D is preferably 5 parts by weight or less, and more preferably 3 parts by weight or less.

[0080] In the curable composition, when the total content of component A and component B is 100 parts by weight, the lower limit of the content of component E is preferably 1 part by weight or more, and more preferably 2 parts by weight or more. When the total content of component A and component B is 100 parts by weight, the upper limit of the content of component E is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, still more preferably 10 parts by weight or less, and particularly preferably 5 parts by weight or less.

[0081] In the curable composition, when the total content of component A and component B is 100 parts by weight, the lower limit of the content of component F is preferably 0.01 part by weight or more, and more preferably 0.1 part by weight or more. When the total content of component A and component B is 100 parts by weight, the upper limit of the content of component E is preferably 5 parts by weight or less, more preferably 3 parts by weight or less, still more preferably 2 parts by weight or less, and particularly preferably 1 part by weight or less.

[0082] 〔3. Form of the curable composition〕 The curable composition containing components A to D may be of a one-component type or a multi-component type. The one-component curable composition is prepared by premixing all the compounding components and then storing them in a sealed manner. The one-component curable composition cures due to the moisture in the environment after use. In the multi-component curable composition, the curing catalyst and other components are prepared separately and mixed together at the time of use. The multi-component curable composition may further include other agents (such as colorants) with optional configurations in addition to the above components.

[0083] When the curable composition is prepared as a multi-component type, a colorant can be further added during the mixing of each component. For example, a colorant obtained by mixing a pigment, a plasticizer, and, if necessary, a filler and pasting it is preferred because of its high workability.

[0084] Also, a retarder can be added to the multi-component curable composition during the mixing of the main agent and the curing agent. Thereby, the curing rate can be finely adjusted at the work site.

[0085] [4. Cured Product] A cured product can be obtained from the above-described curable composition by a known method. For example, the above-described curable composition can absorb the surrounding moisture and spontaneously change into a cured product. The use of the cured product is not particularly limited. As an example, sealing agents for construction and industrial use, materials for electric and electronic parts (such as back surface sealants for solar cells), electrical insulation materials (such as insulating coating materials for electric wires and cables), adhesives, bonding agents, elastic adhesives, contact adhesives, adhesives for tiles, paints, coating materials, sealing materials such as can lids, potting agents for electric and electronic use, films, gaskets, casting materials, various molding materials, artificial marble, rust-proof and waterproof sealants for cut portions of wired glass or laminated glass, and waterproof agents can be mentioned.

[0086] In one embodiment, the cured product is in the form of a film. The lower limit of the thickness of the produced film can be 0.1 mm or more, 0.5 mm or more, 1 mm or more, 5 mm or more, or 10 mm or more. The upper limit of the thickness of the produced film can be 100 mm or less, 90 mm or less, 80 mm or less, 70 mm or less, 60 mm or less, or 50 mm or less.

[0087] The film-like cured product can be produced, for example, by applying a curable composition to a substrate and then curing it. It may be used in a state where the film is peeled off from the substrate, or it may be used in a state where the substrate and the film are integrated. Examples of the uses of the film-like cured product include a sealing material, a coating agent, and an adhesive.

[0088] [5. Summary] The present invention includes the following aspects. <1> A curable composition containing the following components A to D: Component A: A (meth)acrylic polymer having a silyl group; Component B: An epoxy compound; Component C: A curing catalyst; Component D: A polyvalent amine; Here, the above Component A has an XY diblock structure or an XYX triblock structure having an X block and a Y block in the molecule, the repeating unit derived from the silyl group-containing (meth)acrylate monomer contained in the above X block is more than 2.0 on average, the repeating unit derived from the silyl group-containing (meth)acrylate monomer contained in the above Y block is 0 wt% or more and less than 5 wt% based on the weight of all the repeating units contained in the above Y block, the molecular weight distribution (Mw / Mn) is 1.8 or less, the above Component B has an average of 1.0 or less epoxy groups per molecule. <2> The above Component A is CH2 = C(R 1 )COOR 2 (wherein R 1 is a hydrogen atom or a methyl group, and R 2 is a group having 9 or more carbon atoms), and the curable composition according to <1>, which contains 1 wt% or more of the repeating unit derived therefrom. <3> The curable composition according to <1> or <2>, wherein the number average molecular weight of the above-mentioned component A is 2,000 to 50,000. <4> The curable composition according to any one of <1> to <3>, further comprising the following component E: Component E: Drying oil. <5> The curable composition according to any one of <1> to <4>, further comprising the following component F: Component F: Metal salt of a higher fatty acid that is liquid or soluble in alcohol. <6> A cured product obtained by curing the curable composition according to any one of <1> to <5>.

Examples

[0089] 〔Measurement method〕 [Number average molecular weight] The following apparatus was used for the measurement of the number average molecular weight. The measured value is the molecular weight in terms of polystyrene. ·Liquid delivery system: HLC-8120GPC (Tosoh Corporation) ·Column: TSK-GEL H type (Tosoh Corporation) ·Solvent: THF

[0090] [Introduction rate of terminal silyl group] 1 The introduction rate of the terminal silyl group was calculated from the results of 1H-NMR measurement. 1 The following apparatus was used for 1H-NMR measurement. ·Measuring instrument: JNM-LA400 (JEOL Ltd.) ·Solvent: CDCl3

[0091] [Tensile properties of cured product] The curable composition was cured under the conditions of 23°C and 50% RH to obtain a cured product. According to JIS K 6251, a dumbbell-shaped No. 3 test piece was obtained from the cured product, and the tensile properties were measured. The measurement of the tensile properties was carried out at 23°C and 55% RH using an autograph. The evaluation items were the stress at 100% elongation and the elongation at break.

[0092] [Surface tack] The surface of the obtained cured product was confirmed by finger touch and evaluated according to the following criteria. A: No tack is felt at all. B: Almost no tack is felt. C: Tack is clearly felt.

[0093] [Materials] The materials used in the examples and comparative examples are as follows. ● Component A: (Meth)acrylic polymer having a silyl group · (Meth)acrylic polymer (A) having a silyl group obtained in Production Example 1 ● Component A’: (Meth)acrylic polymer having a silyl group other than Component A · (Meth)acrylic polymer (A’) having a silyl group obtained in Comparative Production Example 1 ● Component B: Epoxy compound · Epoxy compound (B-1) (Denacol EX-146, Nagase ChemteX Corporation, p-tert-butylphenyl glycidyl ether, epoxy group per molecule: 1) · Epoxy compound (B-2) (Denacol EX-145, Nagase ChemteX Corporation, phenol (EO)5 glycidyl ether, epoxy group per molecule: 1) · Epoxy compound (B-3) (YED111N, Mitsubishi Chemical Corporation, alkyl glycidyl ether, epoxy group per molecule: 1) ● Component C: Polyvalent amine · Polyvalent amine (C-1) (H30, Mitsubishi Chemical Corporation, ketimine, amine equivalent: 27) · Polyvalent amine (C-2) (FXJ-8074-D, T&K TOKA Co., Ltd., modified aliphatic polyamine, amine equivalent: 445) · Polyvalent amine (C-3) (1,4-diaminobutane, amine equivalent: 44.1) ● Component D: Curing catalyst · Curing catalyst (Neostan U-220H, Nitto Kasei Co., Ltd., dibutyltin) ● Component E: Drying oil · Tung oil ● Component F: Metal salt of higher fatty acid · Metal salt of alcohol-soluble higher fatty acid (potassium 2-ethylhexanoate, 2-hexyl alcohol solution, concentration: 10% by weight) ● Adhesion promoter · N-2-(Aminoethyl)-3-aminopropyltrimethoxysilane (KBM-603, Shin-Etsu Chemical Co., Ltd.) · 3-Glycidoxypropyltrimethoxysilane (Silquest A-187, Momentive) ● Dehydrating agent · Vinyltrimethoxysilane (Silquest A-171, Momentive)

[0094] 〔Production Example 1: Synthesis of (meth)acrylic polymer (A)〕 A (meth)acrylic polymer (A) having a silyl group was synthesized according to the following procedure. (Preparation) 1. A 2000 mL three-necked flask was prepared. 108 g of ethyl acrylate, 707 g of n-butyl acrylate and 186 g of octadecyl acrylate were charged into the flask and mixed. This mixture is referred to as the “(meth)acrylate monomer mixture”. 2. Another stirring container was prepared. 52.7 mg of cupric bromide (CuBr2), 54.4 mg of hexamethyltris(2-aminoethyl)amine (Me6TREN) and 1.82 g of methanol were charged into the stirring container and stirred under a nitrogen stream until a homogeneous solution was obtained. This homogeneous solution is referred to as the “copper solution”. The copper contained in the copper solution corresponds to 15 ppm based on the total amount of the (meth)acrylate monomer mixture. 3. Yet another stirring container was prepared. 30.8 mL of methanol, 1.0 g of ascorbic acid and 1.6 mL of triethylamine were charged into the stirring container and stirred under a nitrogen stream to form a homogeneous solution. This homogeneous solution is referred to as the “ascorbic acid solution”. (First step) 4. Add 5.60 g of ethyl α-bromobutyrate (initiator; 0.029 mol), 20 wt% of the total amount of (meth)acrylate monomer mixture, 10 g of 3-methacryloxypropylmethyldimethoxysilane (0.045 mol; 1.5 molar equivalents relative to the initiator), 107.68 g of methanol, and the total amount of the copper solution to the stirrer, and stir for 30 minutes under a nitrogen stream to obtain a homogeneous solution. The stirrer used at this time was a stirrer equipped with a jacket temperature control, and the jacket temperature was set at 45 °C. 5. When the temperature in the polymerization system reached 40 °C or higher, the polymerization reaction was initiated by continuously dropping an ascorbic acid solution. The dropping rate of the ascorbic acid solution at this time was set to a rate at which 144 mg of ascorbic acid was introduced into the polymerization system per hour. 6. When the temperature in the polymerization system was monitored, the temperature increased simultaneously with the start of dropping of ascorbic acid, and after reaching the maximum temperature, the temperature gradually decreased. When the temperature difference obtained by subtracting the jacket temperature from the temperature in the polymerization system reached 1 °C, a small amount of the reaction solution in the polymerization system was sampled and analyzed by gas chromatography. As a result, 90 wt% of the initially charged (meth)acrylate monomer mixture had been consumed. (Second step) 7. The remainder of the (meth)acrylate monomer mixture that was not introduced in the first step (80 wt% of the total amount) was continuously dropped into the polymerization system over 90 minutes. The dropping rate of the ascorbic acid solution at this time was set to a rate at which 48 mg of ascorbic acid was introduced into the polymerization system per hour. Also, sampling was performed sequentially and analyzed by gas chromatography. Then, polymerization was carried out until 88 wt% of the total amount of the (meth)acrylate monomer mixture introduced into the polymerization system was consumed. (Third step) 8. Add 11 g of 3-methacryloxypropylmethyldimethoxysilane (0.049 mol; 1.6 molar equivalents relative to the initiator) to the polymerization system. The continuous dropping of the ascorbic acid solution was continued until 98 wt% of the total amount of the (meth)acrylate monomer mixture introduced into the polymerization system was consumed. Then, the dropping of the ascorbic acid solution was terminated and the polymerization was terminated. 9. After changing the jacket temperature to 80 °C, the solvent was devolatilized. For devolatilization, a diaphragm pump was used first, and then a vacuum pump was used. After the devolatilization was completed, it was cooled until the jacket temperature reached 60 °C or lower. (Purification) 10. 1000 g of butyl acetate was charged into a jacket temperature-controlled stirring device and mixed and stirred until it became a homogeneous solution with the polymer after devolatilization. An adsorbent was added to this homogeneous solution and stirred for 1 hour. As the adsorbent, 10 g of Kyoward 500SH (Kyowa Chemical Industry Co., Ltd.) and 10 g of Kyoward 700SEN-S (Kyowa Chemical Industry Co., Ltd.) were used. 11. After the stirring was completed, the obtained mixture was filtered through a filter equipped with a bag filter cloth. As a result, a clear polymer solution was obtained. 1.5 g of an antioxidant (Sumilizer GS, Sumitomo Chemical Co., Ltd.) was added to this solution and mixed until it became homogeneous. Then, the solvent was devolatilized from the solution using a diaphragm pump first and then a vacuum pump. In this way, the (meth)acrylic polymer (A) was obtained.

[0095] The (meth)acrylic polymer (A) was an XYX type block copolymer, with a number average molecular weight of 55,000, a molecular weight distribution of 1.11, and the number of silyl groups introduced per molecule being 2.1. Also, the X block of the (meth)acrylic polymer (A) had an average of 2.1 repeating units derived from a silyl group-containing (meth)acrylic acid ester monomer per polymer molecule. The Y block of the (meth)acrylic polymer (A) had 1.1% by weight of repeating units derived from a silyl group-containing (meth)acrylic acid ester monomer (based on the weight of all repeating units contained in the Y block). Note that the number of repeating units derived from the silyl group-containing (meth)acrylic acid ester monomer contained in the Y block was extremely small. Therefore, when calculated to two significant figures, both the repeating units derived from the silyl group-containing (meth)acrylic acid ester monomer contained in the whole molecule and those contained in the entire X block were 2.1.

[0096] [Comparative Production Example 1: Synthesis of (Meth)acrylic Polymer (A’)] A (meth)acrylic polymer (A’) having a silyl group was synthesized according to the following procedure. Since the (meth)acrylic polymer (A’) does not have the structures of the X block and the Y block, it does not correspond to Component A. 1. The inside of a stainless-steel reaction vessel equipped with a stirrer was deoxygenated. 7.7 g of cuprous bromide and 200 g of butyl acrylate were charged into the reaction vessel and stirred while heating. 2. 90 g of acetonitrile and 17.6 g of diethyl 2,5-dibromo adipate (initiator) were added to the reaction vessel and mixed. After adjusting the temperature of the mixed solution to about 80 °C, pentamethyldiethylenetriamine was added to initiate the polymerization reaction. 3. While sequentially adding 800 g of butyl acrylate to the reaction vessel, the polymerization reaction was advanced. During the progress of the polymerization reaction, pentamethyldiethylenetriamine was appropriately added to adjust the polymerization rate. The total amount of pentamethyldiethylenetriamine used during polymerization was 1.4 g. During the progress of the polymerization reaction, the internal temperature of the reaction vessel was adjusted to about 80 °C to about 90 °C. 4. When the monomer conversion rate (polymerization reaction rate) reached about 95% or more, volatile components were removed by devolatilization under reduced pressure to obtain a concentrate of the (meth)acrylic polymer. 5. 200 g of 1,7-octadiene, 260 g of acetonitrile, and 3.1 g of pentamethyldiethylenetriamine were added to the reaction vessel. 6. While adjusting the internal temperature of the reaction vessel to about 80 °C to about 90 °C, the mixture was heated and stirred for several hours. Thereby, the polymer terminal of the (meth)acrylic polymer was reacted with 1,7-octadiene to introduce an alkenyl group to the terminal of the (meth)acrylic polymer. 7. Acetonitrile and unreacted 1,7-octadiene were removed by devolatilization under reduced pressure to obtain a concentrate of the (meth)acrylic polymer having an alkenyl group at the terminal. 8. The concentrate obtained in Step 7 was diluted with butyl acetate, and a filter aid and adsorbents (Kyoward 700SEN and Kyoward 500SH, Kyowa Chemical Industry Co., Ltd.) were added. 9. The mixture obtained in Step 8 was heated and stirred at about 80°C to about 100°C, and then the solid components were filtered off. The filtrate was concentrated to obtain a crude polymer product. 10. A heat stabilizer (Sumilizer GS, Sumitomo Chemical Co., Ltd.) and adsorbents (Kyoward 700SEN and Kyoward 500SH) were added to the obtained crude polymer product. 11. While performing devolatilization under reduced pressure and heating with stirring, the temperature of the crude polymer product was raised, and devolatilization under reduced pressure and heating with stirring were continued at about 170°C to about 200°C for several hours. 12. An adsorbent (Kyoward 700SEN and Kyoward 500SH) and butyl acetate having a weight about 10 times that of the crude polymer product were added to the crude polymer product, and further heating and stirring were carried out at about 170°C to about 200°C for about several hours. 13. The treatment liquid obtained in Step 12 was further diluted with butyl acetate, and then the adsorbent was filtered off. By concentrating the filtrate, a polymer having alkenyl groups at both ends was obtained. 14. To 500 g of the polymer having alkenyl groups at both ends obtained in Step 13, 7.7 g of methyldimethoxysilane, 2.5 g of methyl orthoformate, and 50 mg of a platinum catalyst were mixed, and heating and stirring were carried out at about 100°C for about 1 hour. As the platinum catalyst, an isopropanol solution of a bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane) platinum complex catalyst was used. 15. After heating and stirring, volatile components (unreacted methyldimethoxysilane, etc.) were distilled off under reduced pressure. In this way, a (meth)acrylic polymer (A') having a silyl group was obtained.

[0097] The number of silyl groups possessed by the (meth)acrylic polymer (A') was 2.0 on average per molecule. The (meth)acrylic polymer (A') had a number average molecular weight of 27,000 and a molecular weight distribution of 1.2.

[0098] [Examples 1 to 6, Comparative Examples 1 to 2] Samples for physical property evaluation were prepared according to the following procedure. 1. Each component was prepared in the amounts (unit: g) shown in Table 1. 2. Each component was put into a 150 cc plastic cup and stirred with a spatula. 3. Using a planetary stirring and degassing apparatus (ARE-310, Shinki Co., Ltd.), stirring (1600 rpm × 90 seconds) and degassing (2200 rpm × 300 seconds) were carried out to obtain a curable composition.

[0099] [Results] The results are shown in Table 1. [Table 1]

[0100] The curable compositions according to Examples 1 to 6 contain Component A. The curable compositions according to Comparative Examples 1 and 2 contain a (meth)acrylic polymer other than Component A. As can be seen from Table 1, the cured products according to Examples 1 to 6 had a lower stress at 100% elongation and a greater elongation at break compared to the cured product according to Comparative Example 1. The curable composition according to Comparative Example 2 had very low flexibility as can be seen from the fact that the sample of the cured product cracked when it was prepared. From this, it is suggested that the combination of Components A to D can lower the modulus of the cured product and improve the elongation.

[0101] The curable compositions according to Examples 3 to 6 further contain Components E and F. The curable compositions according to Examples 1 and 2 do not contain either Component E or F. As can be seen from Table 1, the cured products according to Examples 3 to 6 had a reduced surface tack compared to the cured product according to Example 1. From this, it is suggested that the blending of Components E and F can further reduce the surface tack of the cured product in addition to the above-mentioned effects. [Industrial Applicability]

[0102] The curable composition according to one embodiment of the present invention can be suitably used for adhesives, sealing materials, adhesives, mold release agents, vibration-proof materials, vibration-damping materials, sound-proof materials, foaming materials, paints, spraying materials, etc.

Claims

1. A curable composition containing the following components A to D: Component A: A (meth)acrylic polymer having a silyl group; Component B: An epoxy compound; Component C: A curing catalyst; Component D: A polyvalent amine; Here, the above Component A has an XY diblock structure or an XYX triblock structure having an X block and a Y block in the molecule, the repeating unit derived from the silyl group-containing (meth)acrylate monomer contained in the above X block is more than 2.0 on average, the repeating unit derived from the silyl group-containing (meth)acrylate monomer contained in the above Y block is 0% by weight or more and less than 5% by weight based on the weight of all the repeating units contained in the above Y block, the molecular weight distribution (Mw / Mn) is 1.8 or less, the above Component B has an average of 1.0 or less epoxy groups per molecule.

2. The above component A is CH ２ =C(R １ )COOR ２ (In the formula, R １ is a hydrogen atom or a methyl group, and R ２ is a group having 9 or more carbon atoms), and contains 1% by weight or more of a repeating unit derived therefrom. The curable composition according to claim 1.

3. The curable composition according to Claim 1, wherein the number average molecular weight of the above Component A is 2,000 to 50,000.

4. The curable composition according to Claim 1, further containing the following Component E: Component E: Drying oil.

5. The curable composition according to Claim 1, further containing the following Component F: Component F: A metal salt of a higher fatty acid that is liquid or alcohol-soluble.

6. A cured product obtained by curing the curable composition according to any one of Claims 1 to 5.

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