Thiol compounds and their uses

Abstract

To provide a novel thiol compound and uses thereof, and specifically, to provide: a novel thiol compound; a curing agent containing the thiol compound; a resin composition containing the curing agent and an epoxy compound; a resin composition containing the curing agent and an ene compound having a carbon-carbon double bond in the molecule; and adhesives and sealants that contain these resin compositions.SOLUTION: The present invention relates to, inter alia, a dimer of the thiol compound given by formula (II), a resin curing agent that includes the dimer, a resin composition including the curing agent and an epoxy compound or the like, and uses of the resin composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thiol compound and its use. [Background technology]

[0002] It is well known that compounds containing multiple thiol groups in the molecule are useful as curing agents for epoxy resins. For example, an epoxy resin composition has been proposed that uses a polythiol compound as a curing agent and also contains a reaction product of an amine and an epoxy compound as a curing accelerator. This epoxy resin composition is said to have a long pot life and to cure rapidly at relatively low temperatures (see Patent Document 1).

[0003] In addition, an epoxy resin composition has been proposed that contains, as a curing accelerator, a reaction product of an isocyanate compound having one or more isocyanate groups in the molecule and a compound having one or more primary and / or secondary amino groups in the molecule, and this epoxy resin composition is also said to have a long pot life and excellent curability (see Patent Document 2).

[0004] In addition, it is known that sulfur compounds containing ether bonds in their structure, when used as epoxy resin curing agents, can give cured resin products that are excellent in flexibility, moisture resistance, etc. However, when used as adhesives, the flexibility of the structure makes the adhesive strength with the adherend insufficient (see Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-211969 [Patent Document 2] Japanese Patent Application Publication No. 6-211970 [Patent Document 3] International Publication No. 2016 / 171072 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a novel thiol compound and uses thereof. Specifically, the object is to provide a novel thiol compound, a curing agent containing the thiol compound, a resin composition containing the curing agent and an epoxy compound, a resin composition containing the curing agent and an ene compound having a carbon-carbon double bond in the molecule, and an adhesive and a sealant containing these resin compositions. [Means for solving the problem]

[0007] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that a dimer obtained by oxidatively dimerizing a specific trithiol compound is a novel thiol compound, that a composition containing the thiol compound is useful as a curing agent, and that a resin composition containing the curing agent and a specific resin is useful as an adhesive and a sealing material. Based on this finding, the present inventors have conducted further research and have completed the present invention.

[0008] That is, the present invention includes the following aspects. [1] A dimer of a thiol compound represented by formula (II). [ka] [2] The dimer according to [1], which is at least one compound selected from the group consisting of formulae (I-1) to (I-3): [ka] [3] A composition containing a compound represented by formula (II) and a dimer thereof. [ka] [4] The composition according to [3], wherein the ratio of the content of the dimer to the content of the compound represented by formula (II) in the composition is 0.02 to 0.3, and the ratio is a value determined from the peak area ratio of the compound represented by formula (II) and the dimer when the composition is measured by liquid chromatography. [5] A curing agent comprising the composition according to [3] or [4]. [6] A resin composition comprising the curing agent according to [5] and an epoxy compound. [7] The resin composition according to [6], further comprising an amine as a curing accelerator. [8] A resin composition comprising the curing agent according to [5] and an ene compound having a carbon-carbon double bond in the molecule. [9] An adhesive comprising the resin composition according to [6] or [8].

[10] A sealant comprising the resin composition according to [6] or [8].

[11] A cured product of the resin composition according to [6] or [8]. [Effects of the Invention]

[0009] The dimer of the thiol compound represented by formula (II) of the present invention is a novel compound and can be used as a curing agent for various resins. The curing agent preferably contains the thiol compound represented by formula (II) and its dimer. The cured product obtained by reacting a resin composition containing the curing agent and various resins has a reduced crosslink density, which results in improved toughness of the cured product. Therefore, when this resin composition is used as an adhesive, the adhesive strength, which has been a problem in the past, can be improved. Therefore, according to the present invention, adhesives and sealants having particularly excellent adhesive strength can be obtained using such a resin composition as a component.

[0010] In addition, since the curing agent of the present invention has a low viscosity, when used in a resin composition, workability during molding is improved. [Brief explanation of the drawings]

[0011] [Figure 1]1 is an IR spectrum chart of the pale yellow liquid obtained in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Thiol compounds) The novel thiol compound of the present invention is a compound having a disulfide bond (-SS-) obtained by oxidatively polymerizing a trithiol compound represented by formula (II) (1,2,3-tris(3-mercaptopropoxy)propane), and belongs to the class of polymers known as oligomers. Typically, it is a dimer obtained by oxidatively dimerizing the trithiol compound represented by formula (II). The polymer (particularly the dimer) is useful as a curing agent for resins. [ka]

[0013] Among the multimers of the trithiol compound represented by formula (II), typical examples of dimers include thiol compounds represented by formulas (I-1) to (I-3), and the dimer is at least one compound selected from the group consisting of these. [ka]

[0014] The dimer of the trithiol compound represented by formula (II) can be produced, for example, according to the following reaction scheme. [ka] (In the formula, R may be the same or different and represent a methyl group, an ethyl group, a propyl group, or a phenyl group.)

[0015] [Process (1)] Step (1) is a step of producing a compound represented by formula (V) by reacting 1,2,3-triallyloxypropane represented by formula (III) with a thiocarboxylic acid represented by formula (IV).

[0016] 1,2,3-triallyloxypropane represented by formula (III) can be synthesized, for example, by the method described in JP-A-2012-184198.

[0017] Examples of the thiocarboxylic acid represented by formula (IV) include thioacetic acid, thiobutyric acid, thiobenzoic acid, etc. These thiocarboxylic acids can be purchased as commercially available reagents.

[0018] In step (1), the amount (charge amount) of the thiocarboxylic acid represented by formula (IV) used is preferably an appropriate ratio in the range of 2 to 40 times the molar amount of the allyl groups of 1,2,3-triallyloxypropane.

[0019] In step (1), a radical initiator (a) may be used to promote the reaction, and a reaction solvent (b) may be used to facilitate the reaction. Examples of the radical initiator (a) include: Examples of the peroxyalkylene oxide include azobisisobutyronitrile, t-hexylperoxyisopropyl monocarbonate, t-hexylperoxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, t-butylperoxypivalate, t-hexylperoxypivalate, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1,1-bis(t-hexylperoxy)cyclohexane, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, 2,2'-azobis(2-methylbutyronitrile), and dimethyl 2,2'-azobis(2-methylpropionate).

[0020] The amount of radical initiator (a) used (charged amount) is preferably an appropriate ratio in the range of 0.0001 to 10 times the amount of 1,2,3-triallyloxypropane used (charged amount).

[0021] Examples of the reaction solvent (b) include: Examples of the solvent include water, methanol, ethanol, propanol, 2-propanol, butanol, ethyl acetate, propyl acetate, butyl acetate, tetrahydrofuran, dioxane, acetonitrile, benzene, toluene, xylene, dichloromethane, chloroform, carbon tetrachloride, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoric triamide, etc. The reaction solvent (b) may be used alone or in combination of two or more thereof.

[0022] In step (1), the reaction temperature is preferably set in the range of 0 to 150° C. The reaction time is appropriately set depending on the set reaction temperature, but is preferably set in the range of 1 to 120 hours.

[0023] After completion of the reaction in step (1), the reaction solvent and the like may be distilled off from the resulting reaction liquid (reaction mixture), and the reaction product obtained as a residue may then be subjected to step (2). Alternatively, after completion of the reaction in step (1), the resulting reaction liquid may be subjected directly to step (2).

[0024] [Process (2)] Step (2) is a step of solvolyzing (for example, hydrolysis or alcoholysis) the compound represented by formula (V) to produce a mixture (composition) containing 1,2,3-tris(3-mercaptopropoxy)propane represented by formula (II) and its dimer.

[0025] In step (2), examples of the alcohol used in the alcoholysis reaction include: Examples include methanol, ethanol, propanol, 2-propanol, butanol, ethylene glycol, propylene glycol, butylene glycol, and glycerin.

[0026] In step (2), it is preferable to use an acid (c) or a base (d) to promote the reaction, and a reaction solvent (e) may be used to facilitate the reaction. Examples of the acid (c) include: Examples of the acid include hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, carbonic acid, formic acid, acetic acid, benzoic acid, oxalic acid, citric acid, phosphoric acid, hexafluorophosphoric acid, nitric acid, sulfuric acid, methanesulfonic acid, toluenesulfonic acid, trifluoromethanesulfonic acid, boric acid, boron trifluoride, and tetrafluoroboric acid.

[0027] The amount of acid (c) used (charged amount) is preferably an appropriate ratio in the range of 0.0001 to 10 times the amount of the reaction product used (produced amount) in step (1).

[0028] Examples of the base (d) include: Examples of the amines include ammonia, trimethylamine, triethylamine, diisopropylethylamine, diazabicycloundecene, diazabicyclononene, pyridine, lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, cesium hydrogen carbonate, trilithium phosphate, trisodium phosphate, tripotassium phosphate, tricesium phosphate, dilithium hydrogen phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, discesium hydrogen phosphate, lithium dihydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, cesium dihydrogen phosphate, lithium acetate, sodium acetate, potassium acetate, cesium acetate, sodium methoxide, sodium ethoxide, and potassium t-butoxide.

[0029] The amount of base (d) used (charged amount) is preferably an appropriate ratio in the range of 2 to 200 times the amount of the reaction product used (produced amount) in step (1).

[0030] In the solvolysis reaction, it is preferable to use a base from the viewpoint of being able to control the amount of dimer produced.

[0031] Examples of the reaction solvent (e) include: Examples of the solvent include ethyl acetate, propyl acetate, butyl acetate, tetrahydrofuran, dioxane, acetonitrile, benzene, toluene, xylene, dichloromethane, chloroform, carbon tetrachloride, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoric triamide, etc. These may be used in combination as the reaction solvent (e).

[0032] In step (2), the reaction temperature is preferably set in the range of 0 to 150° C. The reaction time is appropriately set depending on the set reaction temperature, but is preferably set in the range of 1 to 120 hours. After completion of the solvolysis reaction, a mixture (composition) of the compound represented by formula (II) and its dimer can be isolated from the resulting reaction solution by, for example, concentrating the reaction solution by distilling off the reaction solvent, solvent extraction, or the like. This mixture (composition) can be used as a hardener for resins. [Process (3)]

[0033] After completion of step (2), the dimer can be further isolated or purified, if necessary, by washing with water or the like, treatment with activated carbon, silica gel chromatography or the like.

[0034] (hardening agent) The dimer of the compound represented by formula (II) can be used as a curing agent for resins, and also as an intermediate raw material for various other sulfur-containing compounds. The curing agent of the present invention contains a dimer of the compound represented by formula (II). Preferably, it is a composition containing the compound represented by formula (II) and the dimer thereof. When the curing agent is a composition containing the compound represented by formula (II) and its dimer, the ratio of the content of the dimer to the content of the compound represented by formula (II) in the composition is usually 0.02 to 0.30, preferably 0.05 to 0.25, and more preferably 0.10 to 0.25, from the viewpoints of the viscosity of the resin composition and the adhesive strength of the cured product. The ratio of the content of each component in the composition is a value calculated using the peak area of each component when the composition serving as a curing agent is analyzed by liquid chromatography. For specific details, see the Examples section.

[0035] (First resin composition) The first resin composition of the present invention is obtained by incorporating the curing agent of the present invention into an epoxy compound (refers to an epoxy resin before curing). That is, the first resin composition contains the curing agent of the present invention and an epoxy compound, and may further contain a curing accelerator, a stabilizer, etc., as necessary.

[0036] The epoxy compound can be any epoxy compound having an epoxy group (glycidyl group) in the molecule, and examples thereof include: Polyglycidyl ethers obtained by reacting epichlorohydrin with polyhydric phenols such as bisphenol A, bisphenol F, bisphenol AD, catechol, and resorcinol, or polyhydric alcohols such as glycerin and polyethylene glycol (for example, bisphenol A epoxy resins); Glycidyl ether esters obtained by reacting hydroxycarboxylic acids such as p-hydroxybenzoic acid and β-hydroxynaphthoic acid with epichlorohydrin; Polyglycidyl esters obtained by reacting polycarboxylic acids such as phthalic acid and terephthalic acid with epichlorohydrin; Glycidyl glycoluril compounds having two or more epoxy groups in the molecule, such as 1,3,4,6-tetraglycidyl glycoluril; Cycloaliphatic epoxy resins such as 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate; Nitrogen-containing cyclic epoxy resins such as triglycidyl isocyanurate and hydantoin-type epoxy resins; In addition, we also offer epoxy phenol novolac resins (phenol novolac type epoxy resins), epoxy cresol novolac resins, epoxy polyolefins, cyclic aliphatic epoxy resins, urethane modified epoxy resins, and more. Examples include epoxy-modified organopolysiloxane compounds obtained by a hydrosilylation addition reaction between an organic compound having a carbon-carbon double bond and a glycidyl group and a silicon compound having a SiH group (for example, the epoxy-modified organopolysiloxane compounds disclosed in JP-A-2004-99751 and JP-A-2006-282988), and these may be used in combination.

[0037] The content of the curing agent of the present invention in the first resin composition of the present invention is usually 0.1 to 60% by weight, preferably 1 to 50% by weight, and more preferably 2 to 30% by weight. The content of the curing agent of the present invention in the first resin composition is preferably set so that the ratio (equivalent ratio) of the number of thiol groups in the curing agent of the present invention to the number of epoxy groups in the composition is 0.1 to 10, and more preferably 0.1 to 1.

[0038] The first resin composition of the present invention may contain, together with the curing agent of the present invention, another thiol compound as a curing agent. Examples of the other thiol compound include: Aliphatic thiol compounds such as ethanedithiol, propanedithiol, hexamethylenedithiol, decamethylenedithiol, tolylene-2,4-dithiol, 2,2-bis(mercaptomethyl)-1,3-propanedithiol, 2-(mercaptomethyl)-2-methyl-1,3-propanedithiol, and 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol; Aromatic thiol compounds such as benzenedithiol, toluenedithiol, and xylenedithiol (p-xylenedithiol); cyclic sulfide compounds such as 1,4-dithiane ring-containing polythiol compounds represented by formula (VI); mercaptoalkyl sulfide compounds such as 3-thiapentane-1,5-dithiol and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol; mercaptopropionic acid esters such as pentaerythritol tetrakis(3-mercaptopropionate); Epoxy resin terminal mercapto compound; 3,6-dioxa-1,8-octanedithiol, a mercaptoalkyl ether disulfide compound represented by formula (VII), 2,2′-[[2,2-bis[(2-mercaptoethoxy)methyl]-1,3-propanediyl]bis(oxy)]bisethanethiol, 3,3′-[[2,2-bis[(3-mercaptopropoxy)methyl]-1,3-propanediyl]bis(oxy)]bis-1-propanethiol, 3-[2,2-bis[(3-mercaptopropoxy)methyl]butoxy]-1-propanethiol, 3-(3-mercaptopropoxy)-2,2-bis[(3-mercaptopropoxy)methyl]-1-propanol, mercaptoalkyl ether compounds such as 2,2-bis[(3-mercaptopropoxy)methyl]-1-butanol; 1,3,4,6-tetrakis(2-mercaptoethyl)glycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl)glycoluril, etc. One or a combination of two or more of these may be used.

[0039] [ka] (In the formula, p represents an integer of 1 to 5.)

[0040] [ka] (In the formula, q represents an integer of 1 to 20.)

[0041] The content of the other thiol compounds in the first resin composition of the present invention is preferably set so that the number of thiol groups derived from the other thiol compounds in the composition is in a ratio (equivalent ratio) of 0 to 100 relative to the number of thiol groups derived from the curing agent of the present invention.

[0042] The first resin composition of the present invention may contain a conventionally known curing agent together with the curing agent of the present invention. Examples of conventionally known curing agents include: In addition to compounds with phenolic hydroxyl groups and acid anhydrides, organic phosphine compounds such as triphenylphosphine, diphenylnaphthylphosphine, and diphenylethylphosphine; Aromatic phosphonium salts; Aromatic diazonium salts; Aromatic iodonium salts; Aromatic selenium salts and the like are included.

[0043] Examples of compounds having a phenolic hydroxyl group include: Examples include bisphenol A, bisphenol F, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol S, tetrachlorobisphenol A, tetrabromobisphenol A, dihydroxynaphthalene, phenol novolac, cresol novolac, bisphenol A novolac, brominated phenol novolac, and resorcinol.

[0044] Examples of acid anhydrides include: Examples of the anhydride include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, trimellitic anhydride, nadic anhydride, himic anhydride, methylnadic anhydride, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, and methylnorbornane-2,3-dicarboxylic acid.

[0045] The first resin composition of the present invention may contain a conventionally known curing accelerator. Examples of the curing accelerator include: Examples of the reaction product include (i) amines, (ii) reaction products of epoxy compounds and amines, and (iii) reaction products of compounds having one or more isocyanate groups in the molecule and compounds having at least one of a primary amino group and a secondary amino group in the molecule, and these may be used in combination.

[0046] (i) As is conventionally known, the amines may be any amines having at least one amino group selected from a primary amino group, a secondary amino group, and a tertiary amino group in the molecule. Examples of such amines include: aliphatic amines such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, 4,4'-diaminodicyclohexylmethane, and dimethylbenzylamine; Aromatic amines such as 4,4'-diaminodiphenylmethane and o-methylaniline; Examples thereof include nitrogen-containing heterocyclic compounds such as 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazoline, piperidine, and piperazine.

[0047] The content of the curing accelerator (particularly, amines) in the first resin composition of the present invention is preferably 0.1 to 30 parts by weight relative to 100 parts by weight of the curing agent of the present invention.

[0048] (ii) The reaction product of an epoxy compound and an amine is a solid that is hardly soluble in epoxy resins at room temperature, but becomes soluble (easily soluble) when heated and functions as a curing accelerator, and is therefore also called a latent curing accelerator (hereinafter, the reaction product of an epoxy compound and an amine may be referred to as a "latent curing accelerator").

[0049] Examples of epoxy compounds that can be used as raw materials for latent curing accelerators include the above-mentioned epoxy compounds, as well as glycidylamine compounds obtained by reacting 4,4'-diaminodiphenylmethane, m-aminophenol, or the like with epichlorohydrin; Examples thereof include monofunctional epoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether, and glycidyl methacrylate.

[0050] Examples of amines used as raw materials for latent curing accelerators include the above-mentioned amines. Among these amines, amines having a tertiary amino group in the molecule are raw materials that provide latent curing accelerators with excellent curing acceleration properties. Examples of such amines include: amines such as dimethylaminopropylamine, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, and N-methylpiperazine; Amines having a tertiary amino group in the molecule, such as imidazole compounds such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole, 2-Dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-phenylimidazoline, 1-(2-hydroxy-3-butoxypropyl)-2-methyl Examples of the tertiary amino acid include alcohols, phenols, thiols, carboxylic acids, and hydrazides having a tertiary amino group in the molecule, such as thiimidazoline, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, N-β-hydroxyethylformolin, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, nicotinic acid, isonicotinic acid, picolinic acid, N,N-dimethylglycine hydrazide, N,N-dimethylpropionic acid hydrazide, nicotinic acid hydrazide, and isonicotinic acid hydrazide.

[0051] In order to further improve the storage stability of the first resin composition of the present invention, an active hydrogen compound having two or more active hydrogen atoms in the molecule may be used as a third component as the raw materials for the latent curing accelerator, in addition to the epoxy compound and amines. Examples of active hydrogen compounds include: Polyhydric phenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol, and phenol novolac resins; Polyhydric alcohols such as trimethylolpropane; Polycarboxylic acids such as adipic acid and phthalic acid; Examples include 1,2-dimercaptoethane, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-propanol, mercaptoacetic acid, anthranilic acid, and lactic acid.

[0052] Furthermore, the latent curing accelerator may be surface-treated with an isocyanate compound or an acidic compound. Examples of the isocyanate compound include: Monofunctional isocyanate compounds such as n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, and benzyl isocyanate; Examples of the polyfunctional isocyanate compound include hexamethylene diisocyanate, toluylene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, and bicycloheptane triisocyanate.

[0053] Instead of this polyfunctional isocyanate compound, a compound containing a terminal isocyanate group obtained by reacting a polyfunctional isocyanate compound with an active hydrogen compound can also be used.Specific examples include an addition reaction product having a terminal isocyanate group obtained by reacting toluylene diisocyanate with trimethylolpropane, and an addition reaction product having a terminal isocyanate group obtained by reacting toluylene diisocyanate with pentaerythritol.

[0054] The acidic substance used for the surface treatment of the latent curing accelerator may be any of a gas, liquid, or solid, and may be any of an inorganic acid or an organic acid. Examples of the acid include carbon dioxide gas, sulfurous acid gas, sulfuric acid, hydrochloric acid, oxalic acid, phosphoric acid, acetic acid, formic acid, propionic acid, adipic acid, caproic acid, lactic acid, succinic acid, tartaric acid, sebacic acid, p-toluenesulfonic acid, salicylic acid, boric acid, tannic acid, alginic acid, polyacrylic acid, polymethacrylic acid, phenol, pyrogallol, phenolic resin, and resorcinol resin.

[0055] The latent curing accelerator can be easily obtained by mixing an epoxy compound, an amine, and, if necessary, an active hydrogen compound, reacting them at a temperature between room temperature and 200°C, solidifying the mixture, and pulverizing it; alternatively, by reacting them in a solvent such as methyl ethyl ketone, dioxane, or tetrahydrofuran, removing the solvent, and then pulverizing the solid content.

[0056] Alternatively, commercially available latent curing accelerators may be used. Examples include "Amicure PN-23 (trade name)," "Amicure PN-H (trade name)," and "Amicure MY-24 (trade name)" manufactured by Ajinomoto Fine-Techno Co., Ltd., and "Novacure HX-3721 (trade name)" and "Novacure HX-3742 (trade name)" manufactured by Asahi Kasei Corporation.

[0057] The content of the latent curing accelerator in the first resin composition of the present invention is preferably 0.1 to 1000 parts by weight relative to 100 parts by weight of the epoxy compound (epoxy resin).

[0058] (iii) A reaction product of a compound having one or more isocyanate groups in the molecule and a compound having at least one of a primary amino group and a secondary amino group in the molecule can be obtained by reacting the two in an organic solvent such as dichloromethane.

[0059] Examples of isocyanate compounds having one or more isocyanate groups in the molecule include: n-Butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-bromophenyl isocyanate, m-chlorophenyl isocyanate, o-chlorophenyl isocyanate, p-chlorophenyl isocyanate, 2,5-dichlorophenyl isocyanate, 3,4-dichlorophenyl isocyanate, 2,6-dimethylphenyl isocyanate, o-fluorophenyl isocyanate, p-fluorophenyl isocyanate, m-tolyl isocyanate, p-tolyl isocyanate, o-trifluoromethylphenyl isocyanate, m-trifluoromethylphenyl isocyanate, benzyl isocyanate, hexamethylene Examples of the isocyanate include diphenylmethane diisocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, 2,2-dimethyldiphenylmethane-4,4'-diisocyanate, tolidine diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, p-phenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, tris-(3-isocyanato-4-methylphenyl)isocyanurate, and tris-(6-isocyanatohexyl)isocyanurate.

[0060] Examples of compounds having at least one of a primary amino group and a secondary amino group in the molecule include: Examples of the alkylamine include dimethylamine, diethylamine, di-n-propylamine, di-n-butylamine, di-n-hexylamine, di-n-octylamine, di-n-ethanolamine, dimethylaminopropylamine, diethylaminopropylamine, morpholine, piperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, piperazine, pyrrolidine, benzylamine, N-methylbenzylamine, cyclohexylamine, metaxylylenediamine, 1,3-bis(aminomethyl)cyclohexane, isophoronediamine, N-aminoethylpiperazine, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-phenylimidazole, and 1,1-dimethylhydrazine.

[0061] In the first resin composition of the present invention, the content of the reaction product of a compound having one or more isocyanate groups in the molecule and a compound having at least one of a primary amino group and a secondary amino group in the molecule is preferably 1 to 10 parts by weight per 100 parts by weight of the epoxy compound (epoxy resin).

[0062] The first resin composition of the present invention may contain a conventionally known stabilizer as long as it does not impair the effects of the present invention. Examples of stabilizers include liquid borate ester compounds (trimethyl borate, triethyl borate, tri-n-propyl borate, triallyl borate, trihexyl borate, etc.) and organic acids (acetic acid, propionic acid, butyric acid, succinic acid, malic acid, citric acid, etc.).

[0063] The first resin composition of the present invention may be any of the following, as long as it does not impair the effects of the present invention: Pigments (titanium white, cyanine blue, watching red, red iron oxide, carbon black, aniline black, manganese blue, iron black, ultramarine blue, Hansa red, chrome yellow, chrome green, etc.), Inorganic fillers (calcium carbonate, kaolin, clay, talc, mica, barium sulfate, lithopone, gypsum, zinc stearate, perlite, quartz, quartz glass, fused silica, silica powder such as spherical silica, spherical alumina, crushed alumina, oxides such as magnesium oxide, beryllium oxide, titanium oxide, nitrides such as boron nitride, silicon nitride, aluminum nitride, carbides such as silicon carbide, hydroxides such as aluminum hydroxide, magnesium hydroxide, metals and alloys such as copper, silver, iron, aluminum, nickel, titanium, diamond, carbon-based materials, etc.), Thermoplastic resins and / or thermosetting resins (homopolymers such as various high-density, medium-density, and low-density polyethylenes, polypropylene, polybutene, and polypentene; ethylene-propylene copolymers; polyamide resins such as nylon-6 and nylon-6,6; vinyl chloride resins; nitrocellulose resins; vinylidene chloride resins; acrylic resins; acrylamide resins; styrene resins; vinyl ester resins; polyester resins; phenolic resins (phenolic compounds); silicone resins; fluorine-based resins; various elastomer resins such as acrylic rubber and urethane rubber; graft copolymers such as methyl methacrylate-butadiene-styrene graft copolymers and acrylonitrile-butadiene-styrene graft copolymers; etc.), Reinforcing agents (glass fiber, carbon fiber, etc.), Anti-sagging agents (hydrogenated castor oil, fine silica anhydride particles, etc.), Matting agents (fine silica, paraffin wax, etc.), Abrasives (zinc stearate, etc.), Internal mold release agents (fatty acids such as stearic acid, fatty acid metal salts of calcium stearate, fatty acid amides such as stearic acid amide, fatty acid esters, polyolefin wax, paraffin wax, etc.), If necessary, additives (modifiers) such as surfactants, leveling agents, antifoaming agents, viscosity adjusting diluents (organic solvents), flexibility imparting agents, coupling agents, fragrances, flame retardants, and antioxidants may be contained in an amount of 0.01 to 50% by weight based on the entire first resin composition (total amount). Furthermore, when the first resin composition of the present invention contains an isocyanate group-containing compound as an additive (modifier), the adhesive strength of the resin composition can be improved while suppressing a decrease in the curability of the resin composition.

[0064] Examples of the isocyanate group-containing compound include: Examples of the isocyanate include n-butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, benzyl isocyanate, hexamethylene diisocyanate, 2-ethylphenyl isocyanate, 2,6-dimethylphenyl isocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, tolidine diisocyanate, isophorone diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, and bicycloheptane triisocyanate.

[0065] The content of the isocyanate group-containing compound in the first resin composition of the present invention is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the epoxy compound (epoxy resin).

[0066] There are no particular limitations on the method for preparing (mixing) the first resin composition of the present invention. The above-mentioned components can be weighed out in predetermined amounts and mixed using an appropriate stirring and mixing device such as a three-roll mill or a planetary mixer, while heating as necessary.

[0067] There are no particular limitations on the method for curing the first resin composition of the present invention, and conventionally known curing devices such as a sealed curing oven or a tunnel oven capable of continuous curing can be used. There are also no particular limitations on the heat source, and conventionally known means such as hot air circulation, infrared heating, and high-frequency heating can be used. The curing temperature and curing time can be set appropriately.

[0068] (Second Resin Composition) The second resin composition of the present invention contains the curing agent of the present invention and an ene compound having a carbon-carbon double bond in the molecule (hereinafter, sometimes simply referred to as "ene compound"). That is, the second resin composition contains the curing agent of the present invention and the ene compound, and may further contain a photopolymerization initiator, a stabilizer, etc., as necessary. The ene compound includes both a polymerizable monomer and a polymerizable oligomer (semi-cured product) having a structure in which the polymerizable monomer is partially polymerized.

[0069] Examples of the polymerizable monomer include: (1) (meth)acrylic acid alkyl ester monomers, (2) a hydroxyl group-containing monomer, (3) a carboxyl group-containing monomer, (4) an amino group-containing monomer, (5) Acetoacetyl group-containing monomers, (6) isocyanate group-containing monomers, (7) a glycidyl group-containing monomer, (8) Monomers containing one aromatic ring; (9) Monomers containing alkoxy groups and oxyalkylene groups, (10) Alkoxyalkyl(meth)acrylamide monomers, (11) (meth)acrylamide-based monomers, (12) monofunctional unsaturated compounds, (13) Polyfunctional unsaturated compounds, etc.

[0070] (1) Examples of (meth)acrylic acid alkyl ester monomers include: methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-propyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, Cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, Examples include isobornyl (meth)acrylate.

[0071] (2) Examples of hydroxyl group-containing monomers include: 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, (Meth)acrylic acid hydroxyalkyl esters such as 8-hydroxyoctyl (meth)acrylate; Caprolactone-modified monomers such as caprolactone-modified 2-hydroxyethyl (meth)acrylate; diethylene glycol (meth)acrylate, oxyalkylene-modified monomers such as polyethylene glycol (meth)acrylate; Others include 2-acryloyloxyethyl 2-hydroxyethyl phthalate, N-methylol (meth)acrylamide, Primary hydroxyl group-containing monomers such as hydroxyethyl acrylamide; 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-chloro 2-hydroxypropyl (meth)acrylate, propylene glycol diglycidyl ether-epoxy di(meth)acrylate, Phenol glycidyl ether-epoxy (meth)acrylate, Secondary hydroxyl group-containing monomers such as bisphenol A diglycidyl ether-epoxy di(meth)acrylate; Examples include tertiary hydroxyl group-containing monomers such as 2,2-dimethyl 2-hydroxyethyl (meth)acrylate.

[0072] (3) Examples of carboxyl group-containing monomers include: Examples include (meth)acrylic acid, acrylic acid dimer, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamido-N-glycolic acid, and cinnamic acid.

[0073] (4) Examples of amino group-containing monomers include: tert-butylaminoethyl (meth)acrylate, ethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, Examples thereof include diethylaminoethyl (meth)acrylate.

[0074] (5) Examples of acetoacetyl group-containing monomers include: 2-(acetoacetoxy)ethyl (meth)acrylate, allyl acetoacetate and the like.

[0075] (6) Examples of isocyanate group-containing monomers include: 2-acryloyloxyethyl isocyanate, 2-Methacryloyloxyethyl isocyanate Examples thereof include alkylene oxide adducts thereof.

[0076] (7) Examples of glycidyl group-containing monomers include: In addition to glycidyl (meth)acrylate, Ethylene glycol diglycidyl ether-epoxy (meth)acrylate, Resorcinol diglycidyl ether-epoxy (meth)acrylate, Bis(4-hydroxyphenyl)sulfide diglycidyl ether-epoxy(meth)acrylate, Phenol novolac epoxy resin-(meth)acrylate, Cresol novolac epoxy resin-(meth)acrylate, Bisphenol (e.g., bisphenol A, bisphenol F) type epoxy resin-(meth)acrylate, Biphenol (e.g., 3,3',5,5'-tetramethylbiphenol) type epoxy resin-(meth)acrylate, Epoxy (meth)acrylates, which are reaction products of epoxy compounds such as tris(2,3-epoxypropyl)isocyanurate-(meth)acrylate with (meth)acrylic acid; Examples include glycidyl (meth)acrylates such as 4-hydroxybutyl (meth)acrylate glycidyl ether.

[0077] (8) Examples of monomers containing one aromatic ring include: phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, styrene, Examples include α-methylstyrene.

[0078] (9) Examples of monomers containing an alkoxy group and an oxyalkylene group include: 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-butoxydiethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, Methoxydipropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, Octoxypolyethylene glycol-polypropylene glycol-mono(meth)acrylate, Lauroxy polyethylene glycol mono(meth)acrylate, Examples include stearoxy polyethylene glycol mono(meth)acrylate.

[0079] (10) Examples of alkoxyalkyl(meth)acrylamide monomers include: methoxymethyl (meth)acrylamide, ethoxymethyl (meth)acrylamide, propoxymethyl (meth)acrylamide, isopropoxymethyl (meth)acrylamide, n-butoxymethyl (meth)acrylamide, isobutoxymethyl(meth)acrylamide and the like.

[0080] (11) Examples of (meth)acrylamide-based monomers include: (meth)acryloylmorpholine, dimethyl(meth)acrylamide, diethyl(meth)acrylamide, (Meth)acrylamide N-methylol (meth)acrylamide and the like are included.

[0081] (12) Examples of monofunctional unsaturated compounds include biphenyl structure-containing (meth)acrylate compounds, more specifically, o-biphenyl (meth)acrylate, m-biphenyl (meth)acrylate, Biphenyl (meth)acrylates such as p-biphenyl (meth)acrylate; o-biphenyloxymethyl (meth)acrylate, m-biphenyloxymethyl (meth)acrylate, p-biphenyloxymethyl (meth)acrylate, o-biphenyloxyethyl (meth)acrylate, m-biphenyloxyethyl (meth)acrylate, p-biphenyloxyethyl (meth)acrylate, o-biphenyloxypropyl (meth)acrylate, m-biphenyloxypropyl (meth)acrylate, biphenyloxyalkyl (meth)acrylates such as p-biphenyloxypropyl (meth)acrylate; (o-biphenyloxy)diethylene glycol (meth)acrylate, (m-biphenyloxy)diethylene glycol (meth)acrylate, (p-biphenyloxy)diethylene glycol (meth)acrylate, (o-biphenyloxy)dipropylene glycol (meth)acrylate, (m-biphenyloxy)dipropylene glycol (meth)acrylate, (p-biphenyloxy)dipropylene glycol (meth)acrylate, (o-biphenyloxy)polyethylene glycol (meth)acrylate, (m-biphenyloxy)polyethylene glycol (meth)acrylate, (p-biphenyloxy)polyethylene glycol (meth)acrylate, (o-biphenyloxy)polypropylene glycol (meth)acrylate, (m-biphenyloxy)polypropylene glycol (meth)acrylate, (p-biphenyloxy)polypropylene glycol (meth)acrylate, etc. Examples include biphenyloxypolyalkylene glycol (meth)acrylate.

[0082] (13) Examples of polyfunctional unsaturated compounds include difunctional monomers, trifunctional or higher functional monomers, urethane (meth)acrylates, the above-mentioned epoxy (meth)acrylates, polyester (meth)acrylates, and polyether (meth)acrylates.

[0083] Specific examples of bifunctional monomers include: ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, Polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, Ethylene oxide modified bisphenol A di(meth)acrylate, Propylene oxide modified bisphenol A di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,6-hexanediol ethylene oxide modified di(meth)acrylate, Glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, Phthalic acid diglycidyl ester di(meth)acrylate, Hydroxypivalic acid modified neopentyl glycol di(meth)acrylate, Isocyanuric acid ethylene oxide modified diacrylate, 2-(meth)acryloyloxyethyl acid phosphate diester and the like.

[0084] Specific examples of tri- or higher functional monomers include: trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, Dipentaerythritol tri(meth)acrylate, Dipentaerythritol tetra(meth)acrylate, Dipentaerythritol penta(meth)acrylate, Dipentaerythritol hexa(meth)acrylate, Tri(meth)acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly(meth)acrylate, Tris(2-(meth)acryloyloxyethyl)isocyanurate, Isocyanuric acid ethylene oxide modified tri(meth)acrylate, Ethylene oxide modified dipentaerythritol penta(meth)acrylate, Ethylene oxide modified dipentaerythritol hexa(meth)acrylate, Ethylene oxide modified pentaerythritol tri(meth)acrylate, Ethylene oxide modified pentaerythritol tetra(meth)acrylate, Examples include succinic acid-modified pentaerythritol tri(meth)acrylate.

[0085] In addition to the polymerizable monomers mentioned above, Divinylbenzene, piperylene, isoprene, pentadiene, vinylcyclohexene, chloroprene, butadiene, methylbutadiene, cyclopentadiene, methylpentadiene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, alkyl vinyl ether, vinyl toluene, vinylpyridine, vinylpyrrolidone, itaconic acid dialkyl ester, fumaric acid dialkyl ester, allyl alcohol, acryloyl chloride, methyl vinyl ketone, N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethylallyl vinyl ketone, 2-chloroethyl vinyl ether, triallyl isocyanurate, tetraallyl glycoluril, N-vinylpyrrolidone, N-vinylcaprolactam, ethylene glycol diallyl carbonate, trimellitic acid triallyl ester, trifluoroethyl (meth)acrylate, tribromobenzyl (meth)acrylate, perfluorooctylethyl (meth)acrylate, sulfur-containing (meth)acrylate, (meth)acryloyloxypropyltris(methoxy)silane and the like.

[0086] In the second resin composition of the present invention, the ene compound may be a combination of the polymerizable monomer and polymerizable oligomer described above, the polymerizable monomer may be a combination of the polymerizable monomers exemplified above (different types of polymerizable monomers may be a combination), and the polymerizable oligomer may be a combination of different types of polymerizable oligomers.

[0087] Regarding the content ratio (proportion) of the curing agent of the present invention to the ene compound in the second resin composition of the present invention, the content of the ene compound is preferably an appropriate ratio in the range of 0.01 to 1000 times (weight ratio) the content of the curing agent of the present invention, and more preferably an appropriate ratio in the range of 0.1 to 100 times (weight ratio).

[0088] In the second resin composition of the present invention, the other thiol compounds may be used in combination with the curing agent of the present invention. Regarding the ratio (proportion) of the content of the curing agent of the present invention to the content of the other thiol compound in the second resin composition of the present invention, the content of the other thiol compound is preferably an appropriate ratio in the range of 0 to 100 times (weight ratio) the content of the curing agent of the present invention, and more preferably an appropriate ratio in the range of 0.1 to 10 times (weight ratio).

[0089] Methods for polymerizing (curing) the second resin composition of the present invention include photocuring and heat curing. Examples of photocuring methods include a method of irradiating with active energy rays, preferably a method of using a photopolymerization initiator in combination. Examples of active energy rays include light, radiation, electromagnetic waves, and electron beams, with electron beams or light in the ultraviolet to infrared wavelength range being preferred. As the light source, for example, an ultra-high pressure mercury light source or a metal halide light source can be used for ultraviolet irradiation, a metal halide light source or a halogen light source can be used for visible light irradiation, and a halogen light source can be used for infrared irradiation. In addition, light sources such as lasers and LEDs that are compatible with emission of various wavelengths, which have become increasingly popular in recent years, may also be used. The irradiation amount of the active energy rays can be appropriately set depending on the type of light source, etc.

[0090] The photopolymerization initiator can be selected from a photoradical polymerization initiator and a photoanionic polymerization initiator, and either of them may be contained in the second resin composition. In addition, in order to improve production efficiency and the properties of the cured product, thermal polymerization (thermal curing) may be used in combination with the photocuring.

[0091] As the photoradical polymerization initiator, any commonly used initiator can be used without any particular limitation, and examples thereof include: acetophenones such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, and 2-methyl-1-{4-(methylthio)phenyl}-2-morpholinopropan-1-one; benzoins such as benzil dimethyl ketal; benzophenones such as benzophenone, 4-phenylbenzophenone, and hydroxybenzophenone; Thioxanthones such as isopropylthioxanthone and 2,4-diethylthioxanthone, Other examples include methylphenyl glyoxylate, and these may be used in combination. If necessary, the photoradical polymerization initiator may be used in combination with a known photopolymerization accelerator such as a benzoic acid such as 4-dimethylaminobenzoic acid or a tertiary amine.

[0092] Any photoanionic polymerization initiator may be used without any particular limitation as long as it is a commonly used one, and examples thereof include onium salts and carbamates. Examples of onium salts include 1,2-diisopropyl-3-(bis(dimethylamino)methylene)guanidinium 2-(3-benzoylphenyl)propionate and 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate. Examples of carbamates include 2-nitrophenylmethylpiperidine-1-carboxylate, 1-(anthraquinone-2-yl)ethylimidazolecarboxylate, 1-(3-(2-hydroxyphenyl)-2-propenoyl)piperidine, and 9-anthranylmethyldiethylcarbamate.

[0093] When photocuring the second resin composition of the present invention, a sensitizer such as pyrene, perylene, acridine orange, thioxanthone, 2-chlorothioxanthone, or benzoflavin can be used.

[0094] The content of the photopolymerization initiator in the second resin composition of the present invention is preferably 0.001 to 20% by weight, and more preferably 0.01 to 10% by weight, based on the entire second resin composition (total amount).

[0095] On the other hand, as a method for thermally curing the second resin composition of the present invention, a method of using a thermal polymerization initiator in combination can be mentioned. The thermal polymerization initiator can be selected from a thermal radical polymerization initiator and a thermal anionic polymerization initiator, and either of them may be contained in the resin composition. The heat curing conditions, ie, the heating temperature and heating time, can be set as appropriate, but are preferably set within the range of 60 to 130°C / 30 to 240 minutes, and more preferably within the range of 70 to 125°C / 30 to 120 minutes.

[0096] As the thermal radical polymerization initiator, any commonly used one can be used without any particular limitation, and examples thereof include diisopropyl peroxydicarbonate, benzoyl peroxide, t-butyl peroxyisobutyrate, t-hexyl peroxyisopropyl monocarbonate, t-hexyl peroxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy 2-ethylhexanoate, t-butyl peroxypivalate, t-hexyl peroxypivalate, and t-butyl peroxyneodecanoate. peroxides such as benzoyl peroxide, t-hexylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1,1-bis(t-hexylperoxy)cyclohexane, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, and lauroyl peroxide; and azo compounds such as azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), and dimethyl 2,2′-azobis(2-methylpropionate), and these may be used in combination.

[0097] The thermal anionic polymerization initiator can be any commonly used one without any particular limitation, and examples thereof include amines, imidazoles, etc., and these may also be used in combination. Examples of amines include diethylenetriamine, triethylenetetramine, isophoronediamine, xylylenediamine, diaminodiphenylmethane, and 1,3,4,6-tetrakis(3-aminopropyl)glycoluril. Examples of imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole.

[0098] The content of the thermal polymerization initiator in the second resin composition of the present invention is preferably 0.001 to 20% by weight, and more preferably 0.01 to 10% by weight, based on the entire second resin composition (total amount).

[0099] In the second resin composition of the present invention, when an epoxy resin (epoxy compound) is contained as an additive (modifier), a photo-cationic polymerization initiator or a thermal-cationic polymerization initiator may be used. As the photocationic polymerization initiator, any commonly used one can be used without any particular limitation, and examples thereof include onium salts and organometallic complexes. Examples of onium salts include diazonium salts, sulfonium salts, and iodonium salts. Examples of organometallic complexes include iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes. Examples of commercially available cationic photopolymerization initiators include "ADEKA Optomer SP-150 (trade name)" and "ADEKA Optomer SP-170 (trade name)" manufactured by ADEKA Corporation, "UVE-1014 (trade name)" manufactured by General Electronics Corporation, "CD-1012 (trade name)" manufactured by Sartomer, and "CPI-100P (trade name)" manufactured by San-Apro Co., Ltd. The counter anion of the photocationic polymerization initiator is SbF6 - , AsF6 - , B(C6F5)4 - , PF6 - etc.

[0100] The thermal cationic polymerization initiator can be used without any particular limitation as long as it is a commonly used one. Examples thereof include various onium salts such as quaternary ammonium salts, phosphonium salts, and sulfonium salts, and organometallic complexes, and these may be used in combination. Examples of commercially available onium salts include "ADEKAOPTON CP-66 (trade name)" and "ADEKAOPTON CP-77 (trade name)" manufactured by ADEKA Corporation, "SAN-AID SI-60L (trade name)," "SAN-AID SI-80L (trade name)," and "SAN-AID SI-100L (trade name)" manufactured by Sanshin Chemical Industry Co., Ltd., and "CI Series (trade name)" manufactured by Nippon Soda Co., Ltd. Examples of organometallic complexes include alkoxysilane-aluminum complexes.

[0101] The second resin composition of the present invention may further contain the stabilizers, additives (modifiers), etc. described in the section on the first resin composition above, as long as the effects of the present invention are not impaired. The additives (modifiers) may be contained in an amount of 0.01 to 50% by weight based on the entire second resin composition (total amount), as necessary.

[0102] The method for preparing (mixing) the second resin composition of the present invention is not particularly limited, and it can be prepared, for example, by mixing the curing agent of the present invention, an ene compound, a photopolymerization initiator and / or a thermal polymerization initiator, and, if necessary, other thiol compounds and additives. Known methods (e.g., the methods described in the section on the first resin composition) can be used as the mixing means. The curing agent of the present invention (and, if necessary, other thiol compounds) may be dissolved or dispersed in advance in a viscosity-adjusting diluent (organic solvent).

[0103] (Uses of resin composition) The first resin composition and the second resin composition of the present invention containing the curing agent of the present invention (these resin compositions may be collectively referred to as "the resin compositions of the present invention") are expected to give cured products with excellent mechanical strength. That is, the resin composition of the present invention can provide a cured product having superior adhesive strength compared to conventional resin compositions containing thiol compounds, and therefore can be suitably used as an adhesive and a sealant. That is, the adhesive and sealant of the present invention contain the above-mentioned resin composition of the present invention as a component.

[0104] The adhesive and sealant of the present invention may contain additives. Examples of additives include flow behavior modifiers such as silicic acid, magnesium silicate, and barium sulfate, thermal conductivity imparting agents such as alumina, conductivity imparting agents such as silver and carbon, and colorants such as pigments and dyes. These additives can be blended during the preparation of the resin composition of the present invention. They may also be mixed with an already prepared resin composition of the present invention. Known methods (such as those described in the first section regarding the resin composition) can be used as the mixing means.

[0105] The adhesive and sealant of the present invention are not particularly limited in their applications and can be applied in various fields.The applications of the adhesive include, for example, adhesives for flexible printed wiring boards; interlayer adhesives for multilayer substrates such as build-up substrates; adhesives for bonding optical components; adhesives for bonding optical disks; adhesives for mounting printed wiring boards; die bonding adhesives; adhesives for semiconductors such as underfills; mounting adhesives for underfills for BGA reinforcement, anisotropic conductive films (ACF), anisotropic conductive pastes (ACP), etc.; adhesives for optical pickups; adhesives for optical path coupling; adhesives used between exterior materials, base materials, ceiling materials and interior materials; adhesives for bonding tiles and stone to exterior wall materials and base materials; adhesives for bonding wood flooring materials, polymer material floor sheets, and floor tiles to various floors; adhesives for structural materials, bodies and parts of automobiles, aircraft, etc.; adhesives for automobile interiors; adhesives for steel plate joints, etc. Applications of sealants include, for example, joint sealants for exterior materials such as various metal panels and siding boards; sealants used between exterior materials, base materials, ceiling materials and interior materials; joint sealants for various concrete products such as roads, bridges, tunnels and breakwaters; sealants for structural materials, bodies and parts of automobiles and aircraft; sealants for steel plate joints; and sealants for medical equipment.

[0106] The resin composition of the present invention can be applied to the adhesives and sealants described above as well as to products (parts and components) in various fields where resin may be used as the material, and can be used as a raw material for materials in the fields of electricity or electronics, optics, architecture, civil engineering, automobiles or aircraft, and medicine, as well as for other daily necessities and miscellaneous goods.

[0107] For example, examples of parts, components and materials in the electrical or electronic field include resin-coated copper foil, prepreg, copper-clad laminate, printed wiring board, solder resist ink, conductive paste, interlayer insulating material, encapsulant, LED encapsulant, insulating material, thermally conductive material, hot melt material, paint, potting agent, etc., but more specifically, interlayer insulating film, wiring coating film and other printed wiring boards, encapsulating materials for electronic components, layer forming materials; Materials for forming display devices such as color filters, films for flexible displays, resist materials, and alignment films; Materials for forming semiconductor devices such as resist materials and buffer coating films; Examples of materials include materials for forming optical components such as holograms, optical waveguides, optical circuits, optical circuit components, and anti-reflection films. Other examples include materials for forming rigid wiring boards and flexible printed wiring boards for semiconductor packaging, mounting materials for semiconductor packaging, semiconductor encapsulants, solar cell encapsulants, insulating films for semiconductors, coverlay films for protecting flexible printed circuits, and coating agents for covering wiring.

[0108] Examples of materials in the optical field include core materials for optical fibers, cladding materials, lenses, and abrasion-resistant coating agents for lenses (for example, hard coat forming solutions).

[0109] Examples of materials in the construction field include coating materials and primers for exterior materials such as various metal panels and siding boards; injection materials used between exterior materials, base materials, ceiling materials and interior materials, vibration-damping materials, soundproofing materials, conductive materials for electromagnetic wave shielding, putty materials; wood flooring materials for various floors, polymer material floor sheets, adhesives for adhering floor tiles; and injection materials for repairing cracks in various exterior and interior materials.

[0110] Examples of materials in the civil engineering field include coating materials, primers, paints, putty materials, injection materials, spraying materials, and formwork for various concrete products such as roads, bridges, tunnels, and breakwaters.

[0111] Examples of materials in the automotive or aircraft fields include structural materials, coating materials for bodies and parts, cushioning materials, vibration-damping materials, sound-proofing materials, and spraying materials; adhesives, coating materials, and foam materials for automotive interiors; and coating materials for steel plate seams.

[0112] Examples of materials in the medical field include artificial bones, dental impression materials, medical rubber materials, medical adhesives, and the like. [Example]

[0113] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited thereto. The main raw materials used are as follows:

[0114] 1,2,3-triallyloxypropane (synthesized in accordance with the method described in JP 2012-184198 A. Compound represented by formula (III)) Thioacetic acid (Tokyo Chemical Industry Co., Ltd.) 48% sodium hydroxide solution (Wako Pure Chemical Industries, Ltd.) Sulfuric acid (Wako Pure Chemical Industries, Ltd.)

[0115] (A) Hardener 1,2,3-tris(3-mercaptopropoxy)propane (see Synthesis Example 1, a compound represented by formula (II)) Trimethylolpropane tris(3-mercaptopropionate) (manufactured by SC Organic Chemicals, trade name "TMMP", compound represented by formula (VIII), thiol equivalent: 133) [ka]

[0116] (B) Curing accelerator Dimethylbenzylamine (Wako Pure Chemical Industries, Ltd.) (C) Epoxy compounds (epoxy resins) Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "jER828", epoxy equivalent: 187.0) Glycerol triglycidyl ether (manufactured by Anhui Xinyuan Technology Co., Ltd., product name "XY633", epoxy equivalent: 149.9)

[0117] The methods for measuring the storage modulus and adhesive strength in the evaluation tests employed in the examples and comparative examples are as follows.

[0118] [Viscosity measurement] The viscosity of the compound used as the curing agent and the epoxy resin composition was measured at 25°C using a viscometer (manufactured by UBM, "Rheosol-G5000"). The smaller the viscosity (lower the viscosity), the better the workability when preparing the epoxy resin composition and when using the resin composition as an adhesive.

[0119] [Storage modulus measurement] The epoxy resin composition was cured (80°C / 1 hour), and the storage modulus G' (MPa) of the resulting cured product (test piece: length 25 mm × width 5 mm × thickness 1 mm) was measured at 25°C (frequency: 1 Hz) using a dynamic viscoelasticity measuring device (UBM, "Rheosol-G5000"). The smaller the storage modulus (lower the elasticity), the more excellent the impact resistance of the cured product.

[0120] [Adhesion strength measurement] For two SUS plates (length 100 mm × width 25 mm × thickness 1.6 mm), an epoxy resin composition (adhesive) was applied to one side of each SUS plate in an area (length 12.5 mm × width 25 mm) extending 12.5 mm from one end (longitudinal direction). Next, two SUS plates were laminated together so that the coated surfaces were in contact with each other, and then heated (80°C / 1 hour to cure the epoxy resin composition) to prepare a test piece. The tensile shear adhesive strength (MPa) of this test piece was measured in accordance with JIS K6850. The greater the shear strength, the more suitable the epoxy resin composition is recognized as an adhesive.

[0121] <Synthesis of thiol compounds> Example 1 A 500 mL three-necked recovery flask was charged with 50.95 g (240.0 mmol) of 1,2,3-triallyloxypropane and 190.00 g of butyl acetate. The mixture was heated to 50°C, and then 73.07 g (960.0 mmol) of thioacetic acid was added dropwise. The mixture was stirred at 67°C for 44 hours. The reaction mixture was then concentrated. 66.00 g (792.0 mmol) of 48% aqueous sodium hydroxide solution and 920.0 g of ion-exchanged water were added to the resulting reaction product, and the mixture was stirred at 70°C for 24 hours. The resulting reaction mixture was neutralized with sulfuric acid and then washed five times with a 2:1 weight ratio of butyl acetate to ion-exchanged water. The washed organic layer was concentrated to obtain 66.12 g of a brown liquid (crude product). 6.20 g of this crude product was purified by silica gel column chromatography (chloroform / ethyl acetate=12 / 1 (volume ratio)) to obtain 0.10 g of a pale yellow liquid (column yield: 1.6%).

[0122] This pale yellow liquid 1 The H-NMR spectrum data was as follows: · 1 H-NMR (CDCl3) δ: 3.69 (quin., 4H), 3.50 (dd, 18H), 2.75 (t, 4H), 2.62 (q, 8H), 1.95 (quin., 4H), 1.86 (quin., 8H), 1.38 (t, 4H). The IR spectrum data of this pale yellow liquid was as shown in the chart in FIG. Specifically, from these spectral data, 1H-NMR peak at 1.38 (-S H ) integral ratio, IR 755cm -1 Absorption peak of -CSSC- CS -absorption peak) and the like, the obtained pale yellow liquid was identified as an oxidized dimer of the thiol compound represented by formula (II).

[0123] The crude product was analyzed by liquid chromatography (eluent: 20 mM aqueous sodium dihydrogen phosphate / acetonitrile = 1 / 3 (weight ratio), column: Shim-Pack CLC-ODS, detector: PDA (210 nm)). It was confirmed that the crude product contained the thiol compound represented by formula (II) as the main component (peak at 5.6 minutes elution time), and also contained its oxidized dimer (three peaks at 12.6 minutes, 12.9 minutes, and 16.0 minutes elution times). From the peak area ratio between the thiol compound represented by formula (II) and its oxidized dimer (total of three peaks), it was confirmed that the ratio of the content of the oxidized dimer to the content of the thiol compound represented by formula (II) was 0.20 (20% in percentage).

[0124] In addition, LC / MS analysis (eluent: 5 mM ammonium formate aqueous solution / acetonitrile = 1 / 3 (volume ratio), column: Aquity UPLC BEH C18, detector: PDA (210 nm)) revealed that the m / z of the peak detected at 5.6 minutes in the liquid chromatographic analysis was 315.1115 (H + The m / z values of the peaks detected at 12.6, 12.9, and 16.0 minutes were all 644.2272 (NH4 + It was confirmed that the peaks were the thiol compound represented by formula (II) and the oxidized dimer (3 isomers).

[0125] Synthesis Example 1 (Synthesis of 1,2,3-(3-mercaptopropyloxy)propane) A 500 mL three-necked flask was charged with 50.95 g (240.0 mmol) of 1,2,3-triallyloxypropane and 190.00 g of butyl acetate. The mixture was heated to 50°C, and then 73.07 g (960.0 mmol) of thioacetic acid was added dropwise. The mixture was then stirred at 67°C for 44 hours. The reaction mixture was then concentrated, and 1.17 g (12.0 mmol) of sulfuric acid and 250.00 g of methanol were added to the resulting reaction product, followed by stirring at 50°C for 48 hours. The resulting reaction mixture was cooled to below 20°C, and a 2 / 1 weight ratio of butyl acetate / ion-exchanged water solution was added. The mixture was then washed five times with ion-exchanged water. The washed organic layer was concentrated and purified by silica gel column chromatography (chloroform / toluene = 3 / 1 volume ratio) to obtain 18.89 g of a colorless, transparent liquid (column yield: 28.6%).

[0126] This colorless and transparent liquid 1 The H-NMR spectrum data was as follows: · 1 H-NMR (CDCl3) δ: 3.69 (t, 2H), 3.56(m, 5H), 3.50 (t, 4H), 2.64 (q, 6H), 1.87 (quin., 6H), 1.39 (t, 3H). 1 From the H-NMR spectrum data, the obtained colorless transparent liquid was identified as the thiol compound represented by formula (II) (1,2,3-(3-mercaptopropyloxy)propane).

[0127] Furthermore, when this colorless, transparent liquid was subjected to liquid chromatography analysis (eluent: 20 mM aqueous sodium dihydrogen phosphate / acetonitrile = 1 / 3 (weight ratio), column: Shim-Pack CLC-ODS, detector: PDA (210 nm)), the thiol compound represented by formula (II) (elution time: peak at 5.6 minutes) was detected, but its oxidized dimer (elution time: three peaks at 12.6 minutes, 12.9 minutes, and 16.0 minutes) was not detected.

[0128] <Evaluation of Epoxy Resin Composition> Example 2 An epoxy resin composition was prepared by mixing 66.8 parts by weight of the crude product (thiol equivalent: 125.0) obtained in Example 1 as a curing agent, 3.3 parts by weight of dimethylbenzylamine as a curing accelerator, and 100.0 parts by weight of jER828 as an epoxy compound. The amount of curing accelerator used was adjusted to 5.0% by weight relative to the curing agent. This epoxy resin composition was subjected to evaluation tests (measurement of viscosity, measurement of storage modulus of the cured product, and measurement of adhesive strength when used as an adhesive), and the test results obtained are shown in Table 1.

[0129] [Example 3, Comparative Examples 1 to 4] Epoxy resin compositions having the formulations shown in Table 1 were prepared in the same manner as in Example 2, and evaluation tests were carried out on these epoxy resin compositions. The test results obtained are as shown in Table 1.

[0130] [Table 1]

[0131] From Table 1, it was confirmed that when jER828 was used as the epoxy compound, and the crude product of Example 1 (including 1,2,3-tris(3-mercaptopropoxy)propane and its dimer) was used as the curing agent (Example 2), the viscosity of the curing agent and epoxy resin composition was low, resulting in excellent handleability, the storage modulus of the cured product was low, resulting in excellent impact resistance, and the shear strength was high, resulting in an excellent adhesive, compared to when only 1,2,3-tris(3-mercaptopropoxy)propane was used (Comparative Example 1).

[0132] Furthermore, when the crude product of Example 1 was used as the curing agent (Example 2), the viscosity of the curing agent and the epoxy resin composition was lower, resulting in better handleability, the storage modulus of the cured product was lower, resulting in better impact resistance, and the shear strength was higher, resulting in an excellent adhesive, compared to when TMMP was used (Comparative Example 2).

[0133] Furthermore, when XY633 was used as the epoxy compound and the crude product of Example 1 was used as the curing agent (Example 3), the viscosity of the curing agent and the epoxy resin composition was lower, resulting in easier handling, and the storage modulus of the cured product was lower, resulting in better impact resistance, and the shear strength was higher, resulting in an excellent adhesive, compared to when only 1,2,3-tris(3-mercaptopropoxy)propane was used (Comparative Example 3).

[0134] In addition, when the crude product of Example 1 was used as the curing agent (Example 3), the viscosity of the curing agent and the epoxy resin composition was lower than when TMMP was used (Comparative Example 4), resulting in better handleability, a lower storage modulus of the cured product resulting in better impact resistance, and a higher shear strength resulting in an excellent adhesive. [Industrial Applicability]

[0135] The oxidized dimer of the compound represented by formula (II) of the present invention is useful as a resin curing agent or an intermediate raw material for various sulfur-containing compounds. Furthermore, a composition containing the compound represented by formula (II) of the present invention and its oxidized dimer is useful as a curing agent for epoxy resins, etc. Furthermore, a resin composition containing the curing agent and an epoxy compound, etc., is suitable for various applications such as adhesion, sealing, encapsulation, casting, molding, painting, and coating.

Claims

1. A dimer of a thiol compound represented by formula (II), 【Chemical 1】 The dimer is at least one compound selected from the group consisting of formulas (I-1) to (I-3). 【Chemistry 2】

2. A composition containing a compound represented by formula (II) and a dimer thereof. 【Chemistry 3】

3. 3. The composition according to claim 2, wherein the ratio of the content of the dimer to the content of the compound represented by formula (II) in the composition is 0.02 to 0.3, and the ratio is a value determined from the peak area ratio of the compound represented by formula (II) and the dimer when the composition is measured by liquid chromatography.

4. A curing agent comprising the composition of claim 2 or 3.

5. A resin composition comprising the curing agent according to claim 4 and an epoxy compound.

6. The resin composition according to claim 5 , further comprising an amine as a curing accelerator.

7. A resin composition comprising the curing agent according to claim 4 and an ene compound having a carbon-carbon double bond in the molecule.

8. An adhesive comprising the resin composition according to claim 5 .

9. An adhesive comprising the resin composition according to claim 7.

10. A sealant comprising the resin composition according to claim 5.

11. A sealant comprising the resin composition according to claim 7.

12. A cured product of the resin composition according to claim 5.

13. A cured product of the resin composition according to claim 7.

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