Thiol compounds and uses thereof

Abstract

The present invention provides a novel thiol compound and a use thereof. Specifically, the present invention provides 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 alkene compound having a carbon-carbon double bond in the molecule, and an adhesive and a sealant containing the resin compositions. The present invention relates to a dimer of a thiol compound represented by formula (II), a resin curing agent containing the dimer, a resin composition containing the curing agent, an epoxy compound and the like, and a use of the resin composition. # imgabs0 #

Description

Technical Field

[0001] The invention relates to a thiol compound and application thereof. Background Art

[0002] It is well known that compounds having a plurality of thiol groups in the molecule can be used as curing agents for epoxy resins. For example, an epoxy resin composition has been proposed, which contains a polythiol compound as a curing agent and a reaction product of an amine and an epoxy compound as a curing accelerator. It is said that this epoxy resin composition has a long pot life and can be cured quickly at a relatively low temperature (see Patent Document 1).

[0003] Another epoxy resin composition has been proposed, which contains 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 as a curing accelerator. This epoxy resin composition is said to also have a long pot life and excellent curability (see Patent Document 2).

[0004] Furthermore, it is known that sulfur compounds containing ether bonds in their structures, when used as epoxy resin curing agents, can impart excellent flexibility and moisture resistance to the cured resin products. On the other hand, when used as adhesives, such sulfur compounds have unsatisfactory adhesive strength to adherends due to the flexibility of their structures (see Patent Document 3).

[0005] Reference List

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 6-211969

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 6-211970

[0009] Patent Document 3: International Publication No. 2016 / 171072 Summary of the invention

[0010] Technical issues

[0011] The object of the present invention is to provide a novel thiol compound and the use of the thiol compound. Specifically, the object of the present invention 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 olefin compound having a carbon-carbon double bond in the molecule, and an adhesive and a sealant containing these resin compositions.

[0012] Problem Solution

[0013] The present inventors have conducted extensive studies to achieve the object and, as a result, have found that a dimer obtained by oxidative dimerization of a specific trithiol compound is a novel thiol compound, a composition containing the thiol compound can be used as a curing agent, and a resin composition containing the curing agent and a predetermined resin can be used as an adhesive and a sealing material. Based on these findings, the present inventors have conducted further studies and completed the present invention.

[0014] Specifically, the present invention includes the following aspects.

[0015] [1] Dimer of a thiol compound represented by formula (II):

[0016] [Chemical formula 1]

[0017]

[0018] [2] The dimer according to [1], which is at least one compound selected from the group consisting of formula (I-1) to (I-3)

[0019] [Chemical formula 2]

[0020]

[0021]

[0022] [3] A composition comprising a compound represented by formula (II):

[0023] [Chemical formula 3]

[0024]

[0025] and its dimers.

[0026] [4] The composition according to [3], wherein

[0027] 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

[0028] This ratio is a value determined based on the peak area ratio of the dimer and the compound represented by formula (II) when the composition is measured by liquid chromatography.

[0029] [5] A curing agent comprising the composition of [3] or [4].

[0030] [6] A resin composition comprising the curing agent of [5] and an epoxy compound.

[0031] [7] The resin composition according to [6], further comprising an amine as a curing accelerator.

[0032] [8] A resin composition comprising the curing agent of [5] and an olefin compound having a carbon-carbon double bond in its molecule.

[0033] [9] An adhesive comprising the resin composition of [6] or [8].

[0034]

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

[0035]

[11] A cured product comprising the resin composition of [6] or [8].

[0036] Advantageous Effects of the Invention

[0037] 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.

[0038] The crosslinking density of the cured product obtained by the reaction of the resin composition containing the curing agent with the resin in various resins is reduced, so that improved toughness can be exhibited. Therefore, the resin composition used as an adhesive can provide improved bonding strength, which has always been a problem in the art. Therefore, by using such a resin composition as a component, the present invention can provide an adhesive and a sealant with particularly excellent bonding strength.

[0039] Furthermore, since the curing agent of the present invention has a low viscosity, when it is used in a resin composition, workability during molding is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 IR spectrum of the light yellow liquid obtained in Example 1. DETAILED DESCRIPTION

[0041] Thiol compounds

[0042] The novel thiol compound of the present invention is a compound having a disulfide bond (-SS-) obtained by oxidative polymerization of a trithiol compound (1,2,3-tris(3-mercaptopropoxy)propane) represented by formula (II), and belongs to a polymer called "oligomer". Generally, the thiol compound is a dimer obtained by oxidative dimerization of the trithiol compound represented by formula (II). The polymer (particularly the dimer) can be used as a resin curing agent.

[0043] [Chemical formula 4]

[0044]

[0045] Among the multimers of the trithiol compound represented by formula (II), typical examples of the dimer include thiol compounds represented by formulae (I-1) to (I-3), and the dimer is at least one compound selected from these compounds.

[0046] [Chemical formula 5]

[0047]

[0048] The dimer of the trithiol compound represented by formula (II) can be produced, for example, according to the following reaction scheme.

[0049] [Chemical formula 6]

[0050]

[0051] (In the formula, R can be the same or different and represent methyl, ethyl, propyl or phenyl.)

[0052] Step (1)

[0053] Step (1) is a step of reacting 1,2,3-triallyloxypropane represented by formula (III) with a thiocarboxylic acid represented by formula (IV) to produce a compound represented by formula (V).

[0054] 1,2,3-Triallyloxypropane represented by formula (III) can be synthesized, for example, according to the method described in JP-A-2012-184198.

[0055] Examples of the thiocarboxylic acid represented by formula (IV) include thioacetic acid, thiobutyric acid and thiobenzoic acid. These thiocarboxylic acids may be commercially available reagents.

[0056] In step (1), the amount of the thiocarboxylic acid represented by formula (IV) used (input amount) is preferably an appropriate ratio within the range of 2 to 40 times the molar amount of the allyl group of 1,2,3-triallyloxypropane.

[0057] In step (1), a free radical initiator (a) may be used to promote the reaction. A reaction solvent (b) may also be used to promote the reaction.

[0058] Examples of the free radical initiator (a) include azobisisobutyronitrile, tert-hexylperoxyisopropyl monocarbonate, tert-hexylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, tert-butylperoxypivalate, tert-hexylperoxypivalate, tert-butylperoxyneodecanoate, tert-hexylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1,1-bis(tert-hexylperoxy)cyclohexane, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, 2,2′-azobis(2-methylbutyronitrile) and dimethyl 2,2′-azobis(2-methylpropionate).

[0059] The radical initiator (a) used is preferably used in an appropriate ratio within the range of 0.0001 to 10 times the molar amount (charge amount) of 1,2,3-triallyloxypropane.

[0060] Examples of the reaction solvent (b) 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, hexamethylphosphorus triamide, and the like. The reaction solvent (b) may be one or a combination of two or more thereof.

[0061] In step (1), the reaction temperature is preferably set within a range of 0 to 150° C. The reaction time is appropriately set depending on the set reaction temperature, and is preferably set within a range of 1 to 120 hours.

[0062] After the reaction of step (1) is completed, the reaction solvent and some other components can be distilled off from the resulting reaction solution (reaction mixture), and the reaction product obtained as the residue is subjected to step (2). Alternatively, after the reaction of step (1) is completed, the resulting reaction solution can be directly subjected to step (2).

[0063] Step (2)

[0064] Step (2) is a step of subjecting the compound represented by formula (V) to solvolysis (eg, hydrolysis or alcoholysis) to produce a mixture (composition) containing 1,2,3-tris(3-mercaptopropoxy)propane represented by formula (II) and its dimer.

[0065] Examples of the alcohol used in the alcoholysis of step (2) include methanol, ethanol, propanol, 2-propanol, butanol, ethylene glycol, propylene glycol, butanediol and glycerol.

[0066] In step (2), it is preferred to use an acid (c) or a base (d) to promote the reaction. A reaction solvent (e) may also be used to promote the reaction.

[0067] Examples of the acid (c) include hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, 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.

[0068] The amount of the acid (c) used (input amount) is preferably an appropriate ratio within the range of 0.0001 to 10 times the molar amount (produced amount) of the reaction product used in step (1).

[0069] Examples of the base (d) 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, dicesium 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 tert-butoxide.

[0070] The amount of the base (d) used (input amount) is preferably an appropriate ratio within the range of 2 to 200 times the molar amount (produced amount) of the reaction product used in step (1).

[0071] In the solvolysis reaction, it is preferred to use a base from the viewpoint of controlling the amount of the generated dimer.

[0072] Examples of the reaction solvent (e) include ethyl acetate, propyl acetate, butyl acetate, tetrahydrofuran, dioxane, acetonitrile, benzene, toluene, xylene, dichloromethane, chloroform, carbon tetrachloride, dimethylformamide, dimethylacetamide, dimethyl sulfoxide and hexamethylphosphoric acid triamide. The reaction solvent (e) used may be a combination thereof.

[0073] In step (2), the reaction temperature is preferably set within a range of 0 to 150° C. The reaction time is appropriately set depending on the predetermined reaction temperature, and is preferably set within a range of 1 to 120 hours.

[0074] After the solvolysis reaction is completed, the reaction solution can be concentrated by distilling the reaction solvent or solvent extraction, and the mixture (composition) of the compound represented by formula (II) and its dimer can be extracted from the obtained reaction solution.

[0075] The mixture (composition) can be used as a resin curing agent.

[0076] Step (3)

[0077] After step (2) is completed, the dimer can be further separated or purified by washing with water, activated carbon treatment, silica gel chromatography, or the like as needed.

[0078] Curing agent

[0079] The dimer of the compound represented by formula (II) can be used as a resin curing agent, and the dimer can also be used as an intermediate raw material for various sulfur-containing compounds.

[0080] The curing agent of the present invention contains a dimer of the compound represented by formula (II). Preferably, the curing agent is a composition containing the compound represented by formula (II) and a dimer thereof.

[0081] When the curing agent is a composition containing a compound represented by formula (II) and a dimer thereof, from the perspective of the viscosity of the resin composition and the bonding strength of the cured product, the ratio of the content of the dimer in the composition to the content of the compound represented by formula (II) is generally 0.02 to 0.30, preferably 0.05 to 0.25, and more preferably 0.10 to 0.25.

[0082] The ratio of the components contained in the composition is a value calculated from the peak area of ​​each component when the composition as a curing agent is analyzed by liquid chromatography. The details are described in the Example section.

[0083] First resin composition

[0084] The first resin composition of the present invention is obtained by adding the curing agent of the present invention to an epoxy compound (referring to an epoxy resin before curing).

[0085] Specifically, the first resin composition contains the curing agent of the present invention and an epoxy compound, and may optionally contain other components such as a curing accelerator and a stabilizer.

[0086] The epoxy compound used may be any compound having an epoxy group (glycidyl group) in the molecule without any particular limitation. Examples of epoxy compounds include: polyglycidyl ethers (e.g., bisphenol A, bisphenol F, bisphenol AD, catechol, and resorcinol) or polyols (e.g., glycerol and polyethylene glycol) obtained by reacting epichlorohydrin; glycidyl ether esters obtained by reacting hydroxycarboxylic acids (e.g., p-hydroxybenzoic acid, and β-hydroxynaphthoic acid) with epichlorohydrin; polyglycidyl esters obtained by reacting polycarboxylic acids (e.g., 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'-epoxycyclohexane methyl-3,4-epoxycyclohexanecarboxylate; nitrogen-containing cyclic epoxy resins such as triglycidyl isocyanurate and hydantoin epoxy resins; epoxidized phenol novolac resins (phenol novolac type epoxy resins), epoxidized cresol novolac resins, epoxidized polyolefins, cycloaliphatic epoxy resins, polyurethane-modified epoxy resins, and epoxy-modified organopolysiloxane compounds obtained by 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 (e.g., epoxy-modified organopolysiloxane compounds disclosed in Japanese Patent Application Laid-Open Nos. 2004-99751 and 2006-282988). These compounds may be used in combination.

[0087] 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.

[0088] The content of the present curing agent in the first resin composition is preferably set so that the ratio (equivalent ratio) of the number of thiol groups in the present curing agent to the number of epoxy groups in the composition is 0.1 to 10 or further 0.1 to 1.

[0089] The first resin composition of the present invention may contain an additional thiol compound as a curing agent together with the curing agent of the present invention. Examples of such additional thiol compounds include aliphatic thiol compounds such as ethanedithiol, propanedithiol, hexamethylenedithiol, decamethylenedithiol, toluene-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 the 1,4-dithiane ring-containing polythiol compound 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-mercaptopropionic acid ester); epoxy resin sealants such as thiocyanate; terminal mercapto compounds; mercapto alkyl ether compounds, such as 3,6-dioxa-1,8-octanedithiol, mercapto alkyl ether disulfide 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, 2,2-bis[(3-mercaptopropoxy)methyl]-1-butanol; and 1,3,4,6-tetrakis(2-mercaptoethyl)glycoluril and 1,3,4,6-tetrakis(3-mercaptopropyl)glycoluril.

[0090] Among these compounds, one kind of compound may be used, or a combination of two or more kinds of compounds may be used.

[0091] [Chemical formula 7]

[0092]

[0093] (wherein each p represents an integer from 1 to 5).

[0094] [Chemical formula 8]

[0095]

[0096] (wherein q represents an integer from 1 to 20).

[0097] The content of the additional thiol compound in the first resin composition of the present invention is preferably set so that the ratio (equivalent ratio) of the number of thiol groups derived from the additional thiol compound to the number of thiol groups derived from the curing agent of the present invention in the composition is 0 to 100.

[0098] The first resin composition of the present invention may contain a known curing agent together with the curing agent of the present invention. Examples of such known curing agents include compounds having a phenolic hydroxyl group, acid anhydrides, organic phosphine compounds such as triphenylphosphine, diphenylnaphthylphosphine and diphenylethylphosphine, aromatic phosphine salts, aromatic diazonium salts, aromatic iodonium salts and aromatic selenium salts.

[0099] Examples of the compound having a phenolic hydroxyl group 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.

[0100] Examples of the acid anhydride include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, trimellitic anhydride, nadic anhydride, humic anhydride, methylnadic anhydride, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride and methylnorbornene-2,3-dicarboxylic acid.

[0101] The first resin composition of the present invention may contain a known curing accelerator. Examples of curing accelerators 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 primary amino groups or secondary amino groups or both in the molecule. These curing accelerators may be used in combination.

[0102] As is well known, the amine (i) may be any amine having at least one amino group selected from the group consisting of a primary amino group, a secondary amino group and a tertiary amino group in the molecule.

[0103] 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; and nitrogen-containing heterocyclic compounds such as 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazoline, piperidine and piperazine.

[0104] 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.

[0105] The reaction product (ii) of an epoxy compound and an amine is a solid that is poorly soluble in the epoxy resin at room temperature, but becomes soluble (becomes easily soluble) by heating and acts as a curing accelerator; therefore, the reaction product (ii) of an epoxy compound and an amine is also called a "latent curing accelerator" (hereinafter, the reaction product of an epoxy compound and an amine is sometimes referred to as a "latent curing accelerator").

[0106] Examples of epoxy compounds used as a raw material for the latent curing accelerator include, in addition to the above-mentioned epoxy compounds, glycidylamine compounds obtained by reacting 4,4'-diaminodiphenylmethane, m-aminophenol, etc. with epichlorohydrin; and monofunctional epoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether and glycidyl methacrylate.

[0107] Examples of the amine used as a raw material for the latent curing accelerator include the above-mentioned amines. Among these amines, amines having a tertiary amino group in the molecule are used as a raw material for providing a latent curing accelerator having excellent curing acceleration performance. Examples of amines include: amines such as dimethylaminopropylamine, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine, etc.; amines having a tertiary amino group in the molecule, for example: imidazole compounds including 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole; and alcohols, phenols, thiols, carboxylic acids and hydrazides having a tertiary amino group in the molecule, for example, 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-methylimidazoline, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, N-β-hydroxyethylmorpholine, 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.

[0108] In order to further improve the storage stability of the first resin composition of the present invention, in addition to the above-mentioned epoxy compound and amine, an active hydrogen compound having two or more active hydrogens in the molecule may be used as a third component as a raw material of a latent curing accelerator.

[0109] Examples of the active hydrogen compound include polyphenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol and phenol novolac resins; polyols such as trimethylolpropane; polycarboxylic acids such as adipic acid and phthalic acid; 1,2-dimercaptoethane, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-propanol, thioglycolic acid, anthranilic acid and lactic acid.

[0110] In addition, the latent curing accelerator may be surface treated with an isocyanate compound or an acidic compound. Examples of isocyanate compounds include monofunctional isocyanate compounds such as n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, and benzyl isocyanate; and polyfunctional isocyanate compounds such as hexamethylene diisocyanate, toluene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, xylylene diisocyanate, p-phenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, and dicycloheptane triisocyanate.

[0111] In addition to the polyfunctional isocyanate compound, a terminal isocyanate-containing compound obtained by reacting a polyfunctional isocyanate compound with an active hydrogen compound can also be used. Specific examples include a terminal isocyanate-containing addition reaction product obtained by reacting toluene diisocyanate with trimethylolpropane, and a terminal isocyanate-containing addition reaction product obtained by reacting toluene diisocyanate with pentaerythritol.

[0112] The acidic substance used for the surface treatment of the latent curing accelerator can be any one of gas, liquid or solid, and can be an inorganic acid or an organic acid. Examples of the acidic substance include carbon dioxide gas, sulfur dioxide 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.

[0113] The latent curing accelerator can be easily obtained by mixing an epoxy compound and an amine (optionally with an active hydrogen compound), reacting the mixture at a temperature ranging from room temperature to 200° C., curing and pulverizing, or by reacting the mixture in a solvent such as methyl ethyl ketone, dioxane or tetrahydrofuran, removing the solvent and then pulverizing the solid.

[0114] Alternatively, a commercially available latent curing accelerator may be used. Examples of commercially available products include Amicure PN-23 (trade name), Amicure PN-H (trade name), and Amicure MY-24 (trade name) produced by Ajinomoto Fine Technologies Co., Ltd.; and Novacure HX-3721 (trade name), Novacure HX-3742 (trade name) produced by Asahi Kasei Corporation.

[0115] 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).

[0116] The reaction product (iii) of a compound having one or more isocyanate groups in the molecule and a compound having a primary amino group or a secondary amino group or both in the molecule can be obtained by reacting the two compounds in an organic solvent such as dichloromethane.

[0117] Examples of the isocyanate compound 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 isocyanate, Methyl diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, 2,2-dimethyldiphenylmethane-4,4'-diisocyanate, ditolyl 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.

[0118] Examples of the compound having a primary or secondary amino group or both in the molecule 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, m-xylylenediamine, 1,3-bis(aminomethyl)cyclohexane, isophoronediamine, N-aminoethylpiperazine, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-phenylimidazole and 1,1-dimethylhydrazine.

[0119] 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 a primary amino group or a secondary amino group or both in the molecule is preferably 1 to 10 parts by weight relative to 100 parts by weight of the epoxy compound (epoxy resin).

[0120] The first resin composition of the present invention may contain a known stabilizer as long as the stabilizer does not impair the effect of the present invention. Examples of stabilizers include liquid borate compounds (e.g., trimethyl borate, triethyl borate, tri-n-propyl borate, triallyl borate, trihexyl borate) and organic acids (e.g., acetic acid, propionic acid, butyric acid, succinic acid, malic acid, and citric acid).

[0121] The first resin composition of the present invention may optionally contain the following substances in an amount of 0.01 to 50% by weight based on the entire first resin composition (total amount) as long as the effect of the present invention is not impaired: pigments (for example, titanium white, cyanine blue, observation red, iron oxide red, carbon black, aniline black, manganese blue, iron black, ultramarine, Hansa red, chrome yellow and chrome green); inorganic fillers (for example, calcium carbonate, kaolin, clay, talc, mica, barium sulfate, zinc lithopone, gypsum, zinc stearate, oxides (for example, perlite, quartz, quartz glass); , silica powder (fused silica, spherical silica, etc.), spherical alumina, crushed alumina, magnesium oxide, beryllium oxide and titanium oxide, nitrides (such as boron nitride, silicon nitride and aluminum nitride), carbides (such as silicon carbide), hydroxides (such as aluminum hydroxide and magnesium hydroxide), metals and alloys (such as copper, silver, iron, aluminum, nickel and titanium) and carbon-based materials (such as diamond and carbon); thermoplastic resins and / or thermosetting resins (such as high-density, medium-density and low-density polyethylene, polypropylene, polybutylene and polypentene Homopolymers such as 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, fluororesins, elastomeric resins such as acrylic rubber and polyurethane rubber, graft copolymers such as methyl methacrylate-butadiene-styrene graft copolymers and acrylonitrile-butadiene-styrene graft copolymers); reinforcing agents (e.g., glass fiber and carbon fiber); anti-sagging agents (e.g., hydrogenated castor oil and fine silicic anhydride); matting agents (e.g., fine silica and paraffin); abrasives (e.g., zinc stearate); internal mold release agents (e.g., 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 waxes and paraffin); additives (modifiers) such as surfactants, leveling agents, defoamers, viscosity regulating diluents (organic solvents), softeners, coupling agents, fragrances, flame retardants and antioxidants.

[0122] Furthermore, by adding an isocyanate group-containing compound as an additive (modifier) ​​to the first resin composition of the present invention, it is possible to improve the adhesive force while limiting the decrease in the curability of the resin composition.

[0123] Examples of the isocyanate group-containing compound 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, ditolyl diisocyanate, isophorone diisocyanate, xylylene diisocyanate, p-phenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, and bicycloheptane triisocyanate.

[0124] 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 relative to 100 parts by weight of the epoxy compound (epoxy resin).

[0125] The method for preparing (mixing) the first resin composition of the present invention is not particularly limited. A predetermined amount of the above components may be taken and weighed, and then mixed using an appropriate stirring and mixing device (eg, a three-roll mill or a planetary mixer), optionally with heating.

[0126] The curing method of the first resin composition of the present invention is not particularly limited. A known curing device such as a closed curing furnace, a tunnel furnace capable of continuous curing, etc. can be used. The heating source is also not particularly limited, and a known method such as hot air circulation, infrared heating, high-frequency heating, etc. can be used. The curing temperature and curing time can be appropriately set.

[0127] Second resin composition

[0128] The second resin composition of the present invention contains the curing agent of the present invention and an olefinic compound having a carbon-carbon double bond in the molecule (hereinafter sometimes referred to as "olefinic compound"). Specifically, the second resin composition contains the curing agent and olefinic compound of the present invention, and may also optionally contain a photopolymerization initiator, a stabilizer, etc.

[0129] The vinyl compound includes a polymerizable monomer and a polymerizable oligomer (semi-cured product) having a structure in which a polymerizable monomer is partially polymerized.

[0130] Examples of polymerizable monomers include

[0131] (1) Alkyl (meth)acrylate monomer,

[0132] (2) Hydroxyl-containing monomers,

[0133] (3) Carboxyl-containing monomers,

[0134] (4) Amino-containing monomers,

[0135] (5) Acetoacetyl-containing monomers,

[0136] (6) Isocyanate-containing monomers,

[0137] (7) Glycidyl-containing monomers,

[0138] (8) Monomers containing an aromatic ring,

[0139] (9) Alkoxy- and oxyalkylene-containing monomers,

[0140] (10) alkoxyalkyl (meth) acrylamide monomer,

[0141] (11) (Meth) acrylamide monomer,

[0142] (12) monofunctional unsaturated compounds, and

[0143] (13) Polyfunctional unsaturated compounds.

[0144] (1) Examples of the alkyl (meth)acrylate monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (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, and isobornyl (meth)acrylate.

[0145] (2) Examples of hydroxyl-containing monomers include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; caprolactone-modified monomers such as caprolactone-modified 2-hydroxyethyl (meth)acrylate; oxyalkylene-modified monomers such as diethylene glycol (meth)acrylate and polyethylene glycol (meth)acrylate; primary hydroxyl-containing monomers such as 2-acryloyloxyethyl-2-hydroxyethyl Monomers containing secondary hydroxyl groups, such as 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 and bisphenol A diglycidyl ether-epoxy di(meth) acrylate; and monomers containing tertiary hydroxyl groups, such as 2,2-dimethyl 2-hydroxyethyl (meth) acrylate.

[0146] (3) Examples of the carboxyl group-containing monomer include (meth)acrylic acid, acrylic acid dimer, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide-N-glycolic acid, and cinnamic acid.

[0147] (4) Examples of the amino group-containing monomer include tert-butylaminoethyl (meth)acrylate, ethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate.

[0148] (5) Examples of the acetoacetyl group-containing monomer include 2-(acetoacetoxy)ethyl (meth)acrylate and allyl acetoacetate.

[0149] (6) Examples of the isocyanate group-containing monomer include 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and alkylene oxide adducts thereof.

[0150] (7) Examples of glycidyl group-containing monomers include glycidyl (meth)acrylates; epoxy (meth)acrylates which are reaction products of epoxy compounds with (meth)acrylic acid, such as 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) epoxy resin-(meth)acrylate, biphenol (e.g. 3,3',5,5'-tetramethylbiphenol) epoxy resin-(meth)acrylate and tris(2,3-epoxypropyl)isocyanurate-(meth)acrylate; and glycidyl (meth)acrylates, such as 4-hydroxybutyl (meth)acrylate glycidyl ether.

[0151] (8) Examples of the monomer 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 and α-methylstyrene.

[0152] (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, octyloxypolyethylene glycol-polypropylene glycol-mono(meth)acrylate, lauryloxypolyethylene glycol mono(meth)acrylate and stearyloxypolyethylene glycol mono(meth)acrylate.

[0153] (10) Examples of the alkoxyalkyl (meth)acrylamide monomer include methoxymethyl (meth)acrylamide, ethoxymethyl (meth)acrylamide, propoxymethyl (meth)acrylamide, isopropoxymethyl (meth)acrylamide, n-butoxymethyl (meth)acrylamide and isobutoxymethyl (meth)acrylamide.

[0154] (11) Examples of the (meth)acrylamide monomer include (meth)acryloylmorpholine, dimethyl(meth)acrylamide, diethyl(meth)acrylamide, and (meth)acrylamide N-methylol(meth)acrylamide.

[0155] (12) Examples of monofunctional unsaturated compounds include (meth)acrylate compounds containing a biphenyl structure. More specific examples include biphenyl (meth)acrylates such as o-biphenyl (meth)acrylate, m-biphenyl (meth)acrylate, and p-biphenyl (meth)acrylate; biphenyloxyalkyl (meth)acrylates such as 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, and p-biphenyloxypropyl (meth)acrylate; and biphenyloxypolyalkylene glycol (meth)acrylates such as (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 and (p-biphenyloxy)polypropylene glycol (meth)acrylate.

[0156] (13) Examples of the polyfunctional unsaturated compound include difunctional monomers, trifunctional or higher-functional monomers, urethane (meth)acrylates, the above-mentioned epoxy (meth)acrylates, polyester (meth)acrylates, and polyether (meth)acrylates.

[0157] Specific examples of the difunctional monomer 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, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, propylene oxide-modified bisphenol A di(meth)acrylate, and polypropylene oxide-modified bisphenol A di(meth)acrylate. Acid esters, 1,6-hexanediol di(meth)acrylate, 1,6-hexanediol ethylene oxide modified di(meth)acrylate, glycerol di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalic acid diglycidyl di(meth)acrylate, hydroxypivalic acid modified neopentyl glycol di(meth)acrylate, isocyanuric acid ethylene oxide modified diacrylate and 2-(meth)acryloyloxyethyl acid phosphoric acid diester.

[0158] Specific examples of the trifunctional or higher-functional monomer 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, glycerol polyglycidyl ether poly(meth)acrylate, tri(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, and succinic acid-modified pentaerythritol tri(meth)acrylate.

[0159] In addition to the above-mentioned polymerizable monomers, examples include 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, vinyl pyridine, vinyl pyrrolidone, dialkyl itaconate, dialkyl fumarate, allyl alcohol, acryloyl chloride, methyl vinyl ketone, N-acrylic acid, Acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethylallyl vinyl ketone, 2-chloroethyl vinyl ether, triallyl isocyanurate, tetraallyl glycoluril, N-vinyl pyrrolidone, N-vinyl caprolactam, ethylene glycol diallyl carbonate, triallyl trimellitate, trifluoroethyl (meth) acrylate, tribromobenzyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, sulfur-containing (meth) acrylate and (meth)acryloxypropyl tri(methoxy) silane.

[0160] In the second resin composition of the present invention, the olefinic compound used can be a combination of the above-mentioned polymerizable monomer and a polymerizable oligomer. The polymerizable monomer used can be a combination of the above-mentioned polymerizable monomers described as an example (it can be a combination of different types of polymerizable monomers), and the polymerizable oligomer used can be a combination of different types of polymerizable oligomers.

[0161] Regarding the content ratio (proportion) of the curing agent of the present invention and the olefinic compound in the second resin composition of the present invention, the content of the olefinic compound relative to the content of the curing agent of the present invention is preferably used in an appropriate ratio within the range of 0.01 to 1000 times (weight ratio), and more preferably in an appropriate ratio within the range of 0.1 to 100 times (weight ratio).

[0162] In the second resin composition of the present invention, the above-mentioned additional thiol compound may be used in combination with the curing agent of the present invention.

[0163] Regarding the content ratio (proportion) of the curing agent of the present invention and the additional thiol compound in the second resin composition of the present invention, the content of the additional thiol compound is preferably an appropriate ratio in the range of 0 to 100 times (weight ratio) relative to 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).

[0164] Methods for polymerizing (curing) the second resin composition of the present invention include photocuring and thermal curing.

[0165] Photocuring methods include methods of irradiating with active energy rays, preferably in combination with methods of using a photopolymerization initiator. Active energy rays include light, radioactive rays, electromagnetic waves, electron beams, etc. Preferably, electron beams or light in the ultraviolet to infrared wavelength range. For example, the light source for ultraviolet irradiation can be an ultrahigh pressure mercury light source or a metal halide light source, the light source for visible light irradiation can be a metal halide light source or a halogen light source, and the light source for infrared irradiation can be a halogen light source. Light sources that are increasingly used recently, such as lasers and LEDs that emit light of various wavelengths, can also be used. The irradiation amount of the active energy ray can be appropriately set according to the type of light source.

[0166] The photopolymerization initiator may be selected from photoradical polymerization initiators and photoanion polymerization initiators, and these initiators may be added to the second resin composition. In the photocuring, thermal polymerization (thermal curing) means may be used in combination to improve production efficiency and characteristics of the cured product.

[0167] The photoradical polymerization initiator used can be any commonly used photoradical polymerization initiator without any particular limitation. Examples of photoradical polymerization initiators include acetophenones, such as 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-methyl-1-{4-(methylthio)phenyl}-2-morpholinepropane-1-one; benzoin, such as benzyl dimethyl ketal; benzophenones, such as benzophenone, 4-phenylbenzophenone and hydroxybenzophenone; thioxanthones, such as isopropylthioxanthone and 2,4-diethylthioxanthone; and methylphenylglyoxylate. These can be used in combination.

[0168] The photoradical polymerization initiator may be optionally used in combination with a known photopolymerization accelerator such as benzoic acid (eg, 4-dimethylaminobenzoic acid) or a tertiary amine.

[0169] The photoanionic polymerization initiator used may be any commonly used photoanionic polymerization initiator without any particular limitation, such as onium salts and carbamates.

[0170] Examples of onium salts include 1,2-diisopropyl-3-(bis(dimethylamino)methylene)guanidine 2-(3-benzoylphenyl)propionate and 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidine n-butyltriphenylborate. Examples of carbamates include 2-nitrophenylmethylpiperidine-1-carboxylate, 1-(anthraquinone-2-yl)ethylimidazolecarboxylate, 1-(3-(2-hydroxyphenyl)-2-acryloyl)piperidine and 9-anthrylmethyldiethylcarbamate.

[0171] In order to photo-cure the second resin composition of the present invention, a sensitizer such as pyrene, perylene, acridine orange, thioxanthone, 2-chlorothioxanthone or benzoflavin may be used.

[0172] The content of the photopolymerization initiator in the second resin composition of the present invention is preferably 0.001 to 20% by weight, more preferably 0.01 to 10% by weight, relative to the entire second resin composition (total amount).

[0173] The method of thermally curing the second resin composition of the present invention includes a method of using a thermal polymerization initiator in combination. The thermal polymerization initiator may be selected from a thermal radical polymerization initiator and a thermal anion polymerization initiator, and these initiators may be added to the resin composition.

[0174] The conditions for heat curing may be appropriately set at a heating temperature and a heating time, preferably within a range of 60 to 130° C. and 30 to 240 minutes, more preferably within a range of 70 to 125° C. and 30 to 120 minutes.

[0175] The thermal free radical polymerization initiator used can be any commonly used thermal free radical polymerization initiator without any particular limitation. Examples include peroxides such as diisopropyl peroxydicarbonate, benzoyl peroxide, tert-butyl peroxyisobutyrate, tert-hexyl peroxyisopropyl monocarbonate, tert-hexyl peroxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy 2-ethylhexanoate, tert-butyl peroxypivalate, tert-hexyl peroxypivalate, tert-butyl peroxyneodecanoate, tert-hexyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1,1-bis(tert-hexylperoxy)cyclohexane, benzoyl peroxide, peroxide 3,5,5-trimethylhexanoyl and lauroyl peroxide; azo compounds such as azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile) and dimethyl 2,2'-azobis(2-methylpropionate). These can be used in combination.

[0176] The thermal anionic polymerization initiator used may be any commonly used thermal anionic polymerization initiator without any particular limitation. Examples include amines and imidazoles. These may be used in combination.

[0177] 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.

[0178] The content of the thermal polymerization initiator in the second resin composition of the present invention is preferably 0.001 to 20% by weight, more preferably 0.01 to 10% by weight, relative to the entire second resin composition (total amount).

[0179] When the second resin composition of the present invention contains an epoxy resin (epoxy compound) as an additive (modifier), a photocationic polymerization initiator or a thermal cationic polymerization initiator may be used.

[0180] The photocationic polymerization initiator used may be any commonly used photocationic polymerization initiator without any particular limitation. Examples of the photocationic polymerization initiator include onium salts and organic metal complexes.

[0181] Examples of onium salts include diazonium salts, sulfonium salts, and iodonium salts.Examples of organic metal complexes include iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes.

[0182] Examples of commercially available photocationic 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 Electric Company, CD-1012 (trade name) manufactured by Sartomer, and CPI-100P (trade name) manufactured by San-Apro Co., Ltd.

[0183] Examples of the counter anion of the photocationic polymerization initiator include SbF6 - 、AsF6 - 、B(C6F5)4 - and PF6 - .

[0184] The thermal cationic polymerization initiator used may be any conventional thermal cationic polymerization initiator without any particular limitation. Examples include various onium salts, such as quaternary ammonium salts, phosphonium salts and sulfonium salts, and organic metal complexes. These may be used in combination.

[0185] Examples of commercially available onium salts include Adeka Opton CP-66 (trade name) and Adeka Opton CP-77 (trade name) produced by ADEKA Corporation, SunAid SI-60L (trade name), SunAid SI-80L (trade name) and SunAid SI-100L (trade name) produced by Sanshin Chemical Industries, Ltd., and CI series (trade name) produced by Nippon Soda Co., Ltd.

[0186] Examples of the organometallic complex include alkoxysilane-aluminum complexes.

[0187] The second resin composition of the present invention may also include stabilizers, additives (modifiers) and other components described in the first resin composition section as long as the effects of the present invention are not impaired. As required, the content of the additives (modifiers) may be 0.01% by weight to 50% by weight relative to the entire second resin composition (total amount).

[0188] The preparation method (mixing method) of the second resin composition of the present invention is not particularly limited. For example, the second resin composition can be prepared by mixing the curing agent of the present invention, the olefinic compound, the photopolymerization initiator and / or the thermal polymerization initiator, and the optional additional thiol compound and additives. The method of mixing the components can be a known method (for example, the method described in the first resin composition part). The curing agent of the present invention (optionally with the additional thiol compound) can be pre-dissolved or dispersed in a viscosity regulating diluent (organic solvent).

[0189] Uses of resin compositions

[0190] The first resin composition and the second resin composition of the present invention, each containing the curing agent of the present invention (may be collectively referred to as "resin composition of the present invention"), are expected to produce a cured product having excellent mechanical strength.

[0191] Specifically, the resin composition of the present invention produces a cured product having better bonding strength than known resin compositions containing thiol compounds. Therefore, the resin composition of the present invention can be suitably used as an adhesive and a sealant. That is, the adhesive and the sealant of the present invention contain the above-mentioned resin composition of the present invention as a component.

[0192] The adhesives and sealants of the present invention may contain additives. Examples of additives include fluid behavior modifiers such as silicic acid, magnesium silicate, and barium sulfate; thermal conductors such as aluminum oxide; conductive agents such as silver and carbon; and colorants such as pigments and dyes. These additives may be added when preparing the resin composition of the present invention. Alternatively, these additives may be mixed with the pre-prepared resin composition of the present invention. The method of mixing the additives may be a known method (e.g., the method described in the first resin composition section).

[0193] The adhesive and sealant of the present invention are not particularly limited in application and can be used in a wide range of fields. For example, the adhesive can be used as an adhesive for flexible printed circuit boards; an interlayer adhesive for multilayer boards such as laminates; an adhesive for joining optical elements; an adhesive for bonding optical disks; an adhesive for mounting objects on printed circuit boards; an adhesive for bonding chips; an adhesive for semiconductors such as bottom fill glue; an adhesive for mounting bottom fill glue for BGA reinforcement, anisotropic conductive film (ACF), anisotropic conductive paste (ACP), etc.; an adhesive for optical pickups; an adhesive for optical path connection; an adhesive used between external materials, substrates, ceiling materials and internal materials; an adhesive for bonding tiles and stone materials to exterior wall materials and substrates; an adhesive for bonding wood floor materials, polymer floor boards, and floor tiles to various floors; an adhesive for structural materials, bodies, and parts of automobiles, aircraft, etc.; an adhesive for automobile interiors; and an adhesive for steel plate joints. The sealant can be used as a sealant for joints of external materials such as various metal plates and side panels; a sealant used between external materials, substrates or ceiling materials and internal materials; a sealant for joints of various concrete products such as roads, bridges, tunnels and breakwaters; a sealant for structural materials, bodies and components of automobiles, airplanes, etc.; a sealant for steel plate joints; and a sealant for medical equipment.

[0194] The resin combination of the present invention can also be applied to products (parts and components) in various fields where the material is resin, in addition to the above-mentioned adhesive and sealant. The resin combination can also be used as a material raw material in the fields of electrical or electronic, optics, construction, civil engineering, automobile, aircraft and medicine, and other daily necessities or groceries.

[0195] Examples of components, members 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, packaging material, LED packaging material, insulating material, thermal conductive material, hot melt material, coating and potting agent. More specific examples include packaging materials and layer forming materials for printed wiring boards and electronic components, such as interlayer insulating films and line coating films; 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; and materials for forming optical elements, such as holograms, optical waveguides, optical circuits, optical circuit elements and anti-reflection films.

[0196] Other examples include materials for forming rigid wiring boards and flexible printed wiring boards for mounting semiconductors, materials for mounting semiconductors, packaging materials for semiconductors, packaging materials for solar cells, insulating films for semiconductors, covering films for protecting flexible printed circuits, and coating agents for covering wiring.

[0197] Examples of materials in the optical field include core materials of optical fibers, cladding materials, lenses, and wear-resistant coating agents (eg, hard coating forming solutions) for lenses.

[0198] Examples of materials in the construction field include: coating materials and primers for exterior materials (such as various metal plates and edge boards); grouting materials used between exterior materials, substrates or ceiling materials and interior materials, shock absorbing materials, sound insulation materials, conductive materials for electromagnetic wave shielding, and putty materials; adhesives for bonding wood flooring materials, polymer flooring boards or floor tiles to various floors; and grouting materials for repairing cracks in various exterior and interior materials.

[0199] Examples of materials in the field of civil engineering include coating materials, primers, paints, putty materials, grouting materials, spraying materials, and casting materials used for various concrete products such as roads, bridges, tunnels, and breakwaters.

[0200] Examples of materials in the automotive or aircraft fields include structural materials, coating materials for car bodies and parts, cushioning materials, shock absorbing materials, sound insulation materials, and spraying materials; adhesives, coating materials, and foam materials for automotive interiors; and coating materials for steel plate joints.

[0201] Examples of materials in the medical field include artificial bones, dental impression materials, medical rubber materials, and medical adhesives.

[0202] Example

[0203] The present invention will be described in more detail below with reference to Examples and Comparative Examples. However, the present invention is not limited to these Examples.

[0204] The main raw materials used are as follows

[0205] -1,2,3-Triallyloxypropane (synthesized according to the method described in Japanese Patent Application Laid-Open No. 2012-184198. Compound represented by formula (III))

[0206] -Thioacetic acid (Tokyo Chemical Industry Co., Ltd.)

[0207] -48% sodium hydroxide aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.)

[0208] - Sulfuric acid (Wako Pure Chemical Industries, Ltd.)

[0209] (A) Curing agent

[0210] -1,2,3-tris(3-mercaptopropoxy)propane (see Synthesis Example 1, compound represented by formula (II))

[0211] -Trimethylolpropane tris(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd., trade name: TMMP, a compound represented by formula (VIII), thiol equivalent: 133)

[0212] [Chemical formula 9]

[0213]

[0214] (B) Curing accelerator

[0215] -Dimethylbenzylamine (Wako Pure Chemical Industries, Ltd.)

[0216] (C) Epoxy compounds (epoxy resins)

[0217] -Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: jER828, epoxy equivalent: 187.0)

[0218] -Glycerol triglycidyl ether (manufactured by Anhui Xinyuan Technology Co., Ltd., trade name: XY633, epoxy equivalent: 149.9)

[0219] The measurement method of the storage elastic modulus and the measurement method of the adhesive strength used in the evaluation tests in Examples and Comparative Examples are as follows.

[0220] [Viscosity measurement]

[0221] The viscosities of the compound used as a curing agent and the epoxy resin composition were measured at 25°C using a viscometer (manufactured by UBM, Rheosol-G5000).

[0222] It is determined that the lower the viscosity (low viscosity), the higher the processability during the preparation of the epoxy resin composition and during the use of the resin composition as an adhesive.

[0223] [Measurement of storage elastic modulus]

[0224] The epoxy resin composition was cured (80°C, 1 hour), and the storage elastic modulus G' (MPa) of the obtained cured product (test sample: length 25 mm x width 5 mm x thickness 1 mm) was measured at 25°C using a dynamic viscoelasticity meter (manufactured by UBM, Rheosol-G5000) (frequency: 1 Hz).

[0225] A smaller storage elastic modulus (lower elasticity) is considered to indicate that the impact resistance of the cured product is more excellent.

[0226] [Measurement of Adhesion Strength]

[0227] The epoxy resin composition (adhesive) was applied to one side of two SUS plates (length 100 mm×width 25 mm×thickness 1.6 mm) over a region extending 12.5 mm from one end (longitudinal direction) (area: length 12.5 mm×width 25 mm).

[0228] Subsequently, the two SUS plates were laminated together with the coated surfaces in contact with each other and then heated (the epoxy resin composition was cured at 80° C. for 1 hour) to prepare a test sample. The tensile shear adhesive strength (MPa) of the test sample was measured according to JIS K6850.

[0229] The higher the shear strength, the more suitable the epoxy resin composition is as an adhesive.

[0230] <Synthesis of Thiol Compounds>

[0231] [Example 1]

[0232] 50.95g (240.0mmol) of 1,2,3-triallyloxypropane and 190.00g of butyl acetate were placed in a 500mL three-necked recovery flask and heated to 50°C. Then, 73.07g (960.0mmol) of thioacetic acid was added dropwise and stirred at 67°C for 44 hours. Subsequently, the reaction solution was concentrated, and 66.00g (792.0mmol) of 48% aqueous sodium hydroxide solution and 920.0g of ion exchange water were added to the resulting reaction product, followed by stirring at 70°C for 24 hours. The resulting reaction solution was neutralized with sulfuric acid and then washed five times with butyl acetate and ion exchange water (butyl acetate / ion exchange water = 2 / 1 weight ratio). The organic layer after concentration and washing gave 66.12g of brown liquid (crude product).

[0233] 6.20 g of the crude product was purified by silica gel column chromatography (chloroform / ethyl acetate=12 / 1 volume ratio) to obtain 0.10 g of a light yellow liquid (column yield: 1.6%).

[0234] Light yellow liquid 1 H-NMR spectrum data are as follows:

[0235] · 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).

[0236] The IR spectrum data of the light yellow liquid is as follows Figure 1 shown.

[0237] According to these spectral data, specifically, according to 1The peak at 1.38 in H-NMR (-S H ) and 755cm- 1 The absorption peak at (-CSSC-of- CS -absorption peak), the obtained light yellow liquid can be identified as the oxidized dimer of the thiol compound represented by formula (II).

[0238] The crude product was subjected to liquid chromatography analysis (eluent: 20 mM sodium dihydrogen phosphate aqueous solution / acetonitrile = 1 / 3 (weight ratio), chromatographic 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 a main component (elution time: peak at 5.6 minutes), and also contained its oxidized dimer (elution time: three peaks at 12.6 minutes, 12.9 minutes and 16.0 minutes).

[0239] The peak area ratio (total of three peaks) of the thiol compound represented by formula (II) and its oxidized dimer showed 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%).

[0240] In addition, LC / MS analysis (eluent: 5 mM ammonium formate aqueous solution / acetonitrile = 1 / 3 (volume ratio), chromatographic column: Acquity UPLC BEH C18, detector: PDA (210 nm)) showed that the m / z of the peak detected at 5.6 minutes in the liquid chromatography analysis was 315.1115 (H + adduct), the m / z of all peaks detected at 12.6 minutes, 12.9 minutes, and 16.0 minutes were 644.2272 (NH4 + adducts), these peaks are the thiol compound represented by formula (II) and its oxidized dimer (three isomers).

[0241] [Synthesis Example 1] Synthesis of 1,2,3-(3-mercaptopropoxy)propane

[0242] 50.95 g (240.0 mmol) of 1,2,3-triallyloxypropane and 190.00 g of butyl acetate were placed in a 500 mL three-necked recovery flask and heated to 50°C. Then, 73.07 g (960.0 mmol) of thioacetic acid was added dropwise, and the mixture was stirred at 67°C for 44 hours. Subsequently, the reaction solution was concentrated, 1.17 g (12.0 mmol) of sulfuric acid and 250.00 g of methanol were added to the resulting reaction product, and then stirred at 50°C for 48 hours. The resulting reaction solution was cooled, butyl acetate and ion exchange water (butyl acetate / ion exchange water = 2 / 1 weight ratio) were added below 20°C, and then washed five times with ion exchange water. The organic layer after washing with water was concentrated and purified by silica gel column chromatography (chloroform / toluene = 3 / 1 volume ratio) to obtain 18.89 g of colorless transparent liquid (column yield: 28.6%).

[0243] Colorless transparent liquid 1 H-NMR spectrum data are as follows:

[0244] · 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).

[0245] according to 1 Based on H-NMR spectrum data, the obtained colorless transparent liquid was identified as a thiol compound (1,2,3-(3-mercaptopropoxy)propane) represented by formula (II).

[0246] The colorless transparent liquid was analyzed by liquid chromatography (eluent: 20 mM sodium dihydrogen phosphate aqueous solution / acetonitrile = 1 / 3 (weight ratio), chromatographic column: Shim-Pack CLC-ODS, detector: PDA (210 nm)). The thiol compound represented by formula (II) was detected (elution time: peak at 5.6 minutes), but its oxidized dimer was not detected (elution time: three peaks at 12.6 minutes, 12.9 minutes and 16.0 minutes).

[0247] <Evaluation of Epoxy Resin Composition>

[0248] [Example 2]

[0249] 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 the curing accelerator was adjusted to 5.0% by weight relative to the curing agent.

[0250] The epoxy resin composition was subjected to evaluation tests (viscosity measurement, storage elastic modulus measurement of the cured product, and adhesive strength measurement when used as an adhesive). The test results obtained are shown in Table 1.

[0251] [Example 3 and Comparative Examples 1 to 4]

[0252] In the same manner as in Example 2, an epoxy resin composition having the formulation shown in Table 1 was prepared and an evaluation test was performed. The test results obtained are shown in Table 1.

[0253] [Table 1]

[0254]

[0255] The results shown in Table 1 indicate that, compared with the use of 1,2,3-tris(3-mercaptopropoxy)propane alone (Comparative Example 1), the use of the crude product of Example 1 (containing 1,2,3-tris(3-mercaptopropoxy)propane and its dimer) as a curing agent and the use of jER828 as an epoxy compound (Example 2) has excellent operability due to the lower viscosity of the curing agent and the epoxy resin composition, excellent impact resistance due to the lower storage elastic modulus of the cured product, and excellent performance as an adhesive due to the higher shear strength.

[0256] Compared with the use of TMMP (Comparative Example 2), the use of the crude product of Example 1 as a curing agent (Example 2) also confirmed that it has excellent workability due to the low viscosity of the curing agent and the epoxy resin composition, excellent impact resistance due to the low storage elastic modulus of the cured product, and excellent performance as an adhesive due to the high shear strength.

[0257] In addition, it was confirmed that when the crude product of Example 1 was used as a curing agent and XY633 was used as an epoxy compound (Example 3), compared with using 1,2,3-tris(3-mercaptopropoxy)propane alone (Comparative Example 3), the curing agent and the epoxy resin composition had lower viscosities and therefore had excellent operability, the cured product had lower storage elastic modulus and therefore had excellent impact resistance, and had excellent performance as an adhesive due to higher shear strength.

[0258] In addition, it was confirmed that when the crude product of Example 1 was used as a curing agent (Example 3), compared with the use of TMMP (Comparative Example 4), the viscosity of the curing agent and the epoxy resin composition was lower, so it had excellent workability, the storage elastic modulus of the cured product was lower, and thus it had excellent impact resistance, and because the shear strength was higher, it had excellent performance as an adhesive.

[0259] Industrial Applicability

[0260] The oxidized dimer of the compound shown in formula (II) of the present invention can be used as a curing agent for resins and an intermediate raw material for various sulfur-containing compounds. In addition, the composition containing the compound shown in formula (II) of the present invention and its oxidized dimer can be used as a curing agent for epoxy resins, etc. In addition, the resin composition containing the curing agent, epoxy compound and other optional components is suitable for various applications, such as bonding, sealing, encapsulation, casting, molding, painting and coating.

Claims

1. A dimer of a thiol compound represented by formula (II): [Chemical formula 1] 2. The dimer according to claim 1, which is at least one compound selected from formula (I-1) to (I-3) [Chemical formula 2] 3. A composition comprising a compound represented by formula (II): [Chemical formula 3] and its dimers.

4. The composition according to claim 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 by the peak area ratio of the dimer to the compound represented by the formula (II) when the composition is measured by liquid chromatography. A curing agent comprising the composition according to claim 3 or 4. A resin composition comprising the curing agent according to claim 5 and an epoxy compound.

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

8. A resin composition comprising the curing agent according to claim 5 and an olefin compound having a carbon-carbon double bond in its molecule. 9 . An adhesive comprising the resin composition according to claim 6 . 10 . An adhesive comprising the resin composition according to claim 8 . 11 . A sealant comprising the resin composition according to claim 6 . 12 . A sealant comprising the resin composition according to claim 8 . 13 . A cured product, which is a cured product of the resin composition according to claim 6 . 14 . A cured product, which is a cured product of the resin composition according to claim 8 .

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