Curable resin composition

Abstract

The present invention addresses the problem of providing a UV / heat-curing type curable resin composition which exhibits sufficiently high adhesion strength even after having only undergone either a UV-curing treatment or a heat-curing treatment. This curable resin composition comprises the following (A) to (F): (A) a polyfunctional (meth)acrylate compound, (B) a monofunctional (meth)acrylate compound having a molecular weight of 400 or less, (C) an epoxy resin, (D) a polyfunctional thiol compound, (E) a radical photopolymerization initiator, and (F) a heat-curing accelerator. The total number (total amount) of (meth)acryloyl groups contained in the polyfunctional (meth)acrylate compound (A), the total number (total amount) of (meth)acryloyl groups contained in the monofunctional (meth)acrylate compound (B), the total number (total amount) of epoxy groups contained in the epoxy resin (C), and the total number (total amount) of thiol groups contained in the polyfunctional thiol compound (D) satisfy a given relationship.

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition, an adhesive containing the same, a cured product obtained by curing the same, and a semiconductor device and a sensor module each containing the cured product. [Background technology]

[0002] Adhesives that are cured by a two-stage process including curing by ultraviolet (UV) irradiation (UV curing) and subsequent curing by heating (thermal curing) (hereinafter referred to as "UV-thermal curing adhesives") are used in many fields (see, for example, Patent Document 1). UV-thermal curing adhesives are useful because they can be cured by heating even when applied to locations where the entire adhesive cannot be irradiated with UV (see, for example, Patent Document 2). Some UV-thermal curing adhesives contain a polyfunctional (meth)acrylate compound and a polyfunctional thiol compound.

[0003] UV-thermosetting adhesives are often used in the manufacture of semiconductor devices, such as image sensor modules, that require highly accurate positioning during assembly. In image sensor modules, the relative positional relationships between components are extremely important. Therefore, highly accurate positioning of each component is essential during the assembly of image sensor modules. By using UV-thermosetting adhesives, components can be temporarily fixed by UV curing, preventing component separation and / or misalignment during thermal curing. Furthermore, intermediate assemblies in which components are temporarily fixed by UV curing before thermal curing can be transported to the thermal curing location without changing the relative positions of the components. Therefore, using UV-thermosetting adhesives in the manufacture of image sensor modules is extremely useful because it improves assembly efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-077024 [Patent Document 2] International Publication No. 2018 / 181421 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional UV-thermosetting adhesives have had the problem that components in intermediate assemblies such as those described above may peel off and / or become misaligned when subjected to impact during transportation.

[0006] This peeling and / or displacement occurs when stress, particularly peel stress and / or shear stress, is applied to the intermediate assembly due to impacts received during transportation, etc. Therefore, to prevent such peeling and / or displacement, it is necessary to have sufficiently high shear strength and peel strength after curing treatment by UV irradiation (UV curing treatment). However, when using conventional UV-thermosetting adhesives, it was difficult to achieve both high shear strength and peel strength after UV curing.

[0007] Depending on the structure of the adherend, there may be areas on the adherend where UV cannot be irradiated to the entire applied UV-thermosetting adhesive during the UV curing process. In such cases, at the completion of the UV curing process, part of the applied UV-thermosetting adhesive remains unreacted, and the UV-cured product that contributes to adhesion (UV-thermosetting adhesive that has only undergone UV curing) only comes into contact with a portion of the adherend's surface area. For this reason, there has been a demand for a UV-thermosetting adhesive that provides a UV-cured product with sufficient adhesive strength, particularly peel strength and shear strength.

[0008] Furthermore, when the intermediate assembly is subjected to a curing treatment by heating (thermal curing treatment), a final assembly is obtained in which the components are bonded together by UV curing and thermal curing. When the intermediate assembly contains unreacted UV-thermal curing adhesive as described above, the cured product contained in the final assembly includes a UV-thermal cured product (a UV-thermal curing adhesive that has undergone both UV curing and thermal curing treatments) and a thermally cured product (a UV-thermal curing adhesive that has undergone only thermal curing treatment). In order to achieve strong bonding between the components in the final assembly, it is necessary that not only the UV-thermal cured product but also the thermally cured product exhibit high adhesive strength. For this reason, a UV-thermal curing adhesive that also produces a thermally cured product exhibiting high adhesive strength has been desired.

[0009] In order to solve the above-mentioned problems of the conventional art, an object of the present invention is to provide a UV-thermosetting curable resin composition that exhibits sufficiently high adhesive strength when subjected to a UV curing treatment and a thermosetting treatment. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention.

[0011] That is, the present invention includes, but is not limited to, the following inventions.

[0012] 1. (A) to (F) below: (A) Polyfunctional (meth)acrylate compound (B) a monofunctional (meth)acrylate compound having a molecular weight of 400 or less (C) Epoxy resin (D) Polyfunctional thiol compounds (E) a photoradical initiator, and (F) Heat curing accelerator Including, [the total number of (meth)acryloyl groups in the (B) monofunctional (meth)acrylate compound+the total number of epoxy groups in the (C) epoxy resin] / [the total number of thiol groups in the (D) polyfunctional thiol compound] is 0.1 to 0.5, [(B) the total number of (meth)acryloyl groups in the monofunctional (meth)acrylate compound] / [(D) the total number of thiol groups in the polyfunctional thiol compound] is 0.05 to 0.45, A curable resin composition, in which [(C) the total number of epoxy groups in the epoxy resin] / [(D) the total number of thiol groups in the polyfunctional thiol compound] is 0.05 to 0.45.

[0013] 2. The curable resin composition according to item 1 above, wherein [the total number of (meth)acryloyl groups in the (B) monofunctional (meth)acrylate compound + the total number of epoxy groups in the (C) epoxy resin] / [the total number of thiol groups in the (D) polyfunctional thiol compound] is 0.3 to 0.5.

[0014] 3. The curable resin composition according to item 1 or 2 above, wherein the polyfunctional thiol compound (D) has three or more thiol groups.

[0015] 4. The curable resin composition according to any one of items 1 to 3 above, wherein the (D) polyfunctional thiol compound includes a trifunctional thiol compound and / or a tetrafunctional thiol compound.

[0016] 5. The curable resin composition according to any one of items 1 to 4 above, wherein the (A) polyfunctional (meth)acrylate compound includes a bifunctional (meth)acrylate compound.

[0017] 6. An adhesive comprising the curable resin composition according to any one of items 1 to 5 above.

[0018] 7. A cured product obtainable by curing the curable resin composition according to any one of items 1 to 5 above, or the adhesive according to item 6 above.

[0019] 8. A semiconductor device comprising the cured product according to item 7 above.

[0020] 9. A sensor module including the cured product according to item 7 above.

[0021] The curable resin composition of the present invention contains, as essential components, (A) a polyfunctional (meth)acrylate compound, (B) a monofunctional (meth)acrylate compound having a molecular weight of 400 or less, (C) an epoxy resin, (D) a polyfunctional thiol compound, (E) a photoradical initiator, and (F) a heat curing accelerator. These components are described below. In this specification, following the convention in the field of synthetic resins, a name including the term "resin," which normally refers to a polymer (particularly a synthetic polymer), may be used to refer to a component that constitutes a curable resin composition before curing, even though the component is not a polymer.

[0022] Furthermore, in this specification, terms such as "(meth)acrylic acid," "(meth)acrylate," "(meth)acrylic," and "(meth)acryloyl" may be used as general terms for "acrylic acid" (or a derivative thereof) and "methacrylic acid" (or a derivative thereof). Each of these terms may be used as an independent term or as part of another term. For example, the term "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid," and the term "(meth)acryloyloxy group" means "acryloyloxy group and / or methacryloyloxy group."

[0023] (A) Polyfunctional (meth)acrylate compound The curable resin composition of the present invention contains a polyfunctional (meth)acrylate compound. The polyfunctional (meth)acrylate compound used in the present invention is a compound containing a total of two or more (meth)acryloyl groups, in the form of (meth)acryloyloxy groups, that react with thiol groups in a polyfunctional thiol compound described below. In other words, the polyfunctional (meth)acrylate compound is a compound having a structure in which one molecule of a compound having two or more hydroxyl groups is esterified with a total of two or more molecules of (meth)acrylic acid (unesterified hydroxyl groups may also be present). However, silane coupling agents having one (meth)acrylate group are not included in the polyfunctional (meth)acrylate compound. Preferably, the polyfunctional (meth)acrylate compound does not contain a silicon atom. As long as the polyfunctional (meth)acrylate compound satisfies the above structural requirements, it may contain a (meth)acryloyl group that is not in the form of a (meth)acryloyloxy group. For example, N,N'-methylenebisacrylamide does not fall under the category of polyfunctional (meth)acrylate compounds. (A) The polyfunctional (meth)acrylate compound preferably includes one having a molecular weight of 100 to 10,000, more preferably 200 to 5,000, even more preferably 200 to 3,000, and particularly preferably 200 to 800.

[0024] Examples of polyfunctional (meth)acrylate compounds include: -di(meth)acrylate of bisphenol A; -di(meth)acrylate of bisphenol F; - polyfunctional (meth)acrylates having an isocyanuric skeleton; -Dimethyloltricyclodecane di(meth)acrylate; - polyfunctional (meth)acrylates of trimethylolpropane or its oligomers; - polyfunctional (meth)acrylate of ditrimethylolpropane; - polyfunctional (meth)acrylates of pentaerythritol or its oligomers; - polyfunctional (meth)acrylates of dipentaerythritol; and -di(meth)acrylate of neopentyl glycol modified trimethylolpropane; -di(meth)acrylate of polyethylene glycol; -di(meth)acrylate of polypropylene glycol; di(meth)acrylates of open-chain or cyclic alkanediols; -di(meth)acrylate of neopentyl glycol; - Polyurethanes containing two or more (meth)acryloyl groups per molecule; - polyesters containing two or more (meth)acryloyl groups in one molecule; -polyfunctional (meth)acrylate of glycerin; etc. Among these, di(meth)acrylate of dimethyloltricyclodecane, (tri / tetra)(meth)acrylate of ditrimethylolpropane, hexa(meth)acrylate of dipentaerythritol, di(meth)acrylate of neopentyl glycol-modified trimethylolpropane, and polyurethane having two (meth)acryloyl groups per molecule are preferred. These may be used alone or in combination of two or more. In this specification, "polyfunctional (meth)acrylate" refers to a compound containing two or more (meth)acryloyloxy groups. For example, "polyfunctional (meth)acrylate of trimethylolpropane or its oligomer" refers to an ester of one molecule of trimethylolpropane or its oligomer with two or more molecules of (meth)acrylic acid.

[0025] In the present invention, the polyfunctional (meth)acrylate compound preferably includes a bifunctional (meth)acrylate compound. A bifunctional (meth)acrylate compound is a polyfunctional (meth)acrylate compound having a total of two (meth)acryloyl groups. Similarly, for example, a trifunctional (meth)acrylate compound and a tetrafunctional (meth)acrylate compound are polyfunctional (meth)acrylate compounds having three and four (meth)acryloyl groups, respectively. In the present invention, a silane coupling agent having a plurality of (meth)acrylate groups is not included in the polyfunctional (meth)acrylate compound. Preferably, the polyfunctional (meth)acrylate compound does not contain a silicon atom.

[0026] (B) a monofunctional (meth)acrylate compound having a molecular weight of 400 or less The curable resin composition of the present invention contains a monofunctional (meth)acrylate compound having a molecular weight of 400 or less. The monofunctional (meth)acrylate compound used in the present invention is a compound containing one (meth)acryloyl group in the form of a (meth)acryloyloxy group that reacts with a thiol group in a polyfunctional thiol compound described below. In other words, the monofunctional (meth)acrylate compound is a compound having a structure in which one molecule of a compound having one or more hydroxyl groups is esterified with one molecule of (meth)acrylic acid (unesterified hydroxyl groups may also be present). However, silane coupling agents having one (meth)acrylate group are not included in this monofunctional (meth)acrylate compound. Preferably, this monofunctional (meth)acrylate compound does not contain a silicon atom. Also preferably, (B) does not have reactive functional groups other than (meth)acrylate groups in its molecule.

[0027] The monofunctional (meth)acrylate compound used in the present invention has a molecular weight of 400 or less. The molecular weight of the monofunctional (meth)acrylate compound is preferably 380 or less, more preferably 360 or less, and even more preferably 340 or less. When a monofunctional (meth)acrylate compound having a molecular weight of more than 400 is used, the peel strength and shear strength during UV curing decrease. This is thought to be because, in the UV-cured curable resin composition (UV-cured product), bulky residues derived from the monofunctional (meth)acrylate compound having a molecular weight of more than 400 gather together to form crystalline moieties, which adversely affect the properties of the UV-cured product.

[0028] Examples of monofunctional (meth)acrylate compounds include: -Ethyl (meth)acrylate, trifluoroethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate esters of monohydric alcohols and (meth)acrylic acid, such as acrylate, ethoxydiethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 2-ethylhexyldiethylene glycol (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, and 3-phenoxybenzyl (meth)acrylate; 2-Hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, octyl acrylate, nonyl acrylate, isononyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, cyclic trimethylolpropane formal acrylate, 1-naphthalenemethyl (meth)acrylate 、1-Ethylcyclohexyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, 1-ethylcyclopentyl (meth)acrylate, 1-methylcyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, nonylphenoxy polyethylene glycol (meth)acrylate, tetrahydrodicyclopentadiene Eni (meth)acrylate, 2-(o-phenylphenoxy)ethyl (meth)acrylate, isobornylcyclohexyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, 1-adamantyl (meth)acrylate, 3-hydroxy-1 - Adamantyl (meth)acrylate, 2-methyl-2-adamantanyl (meth)acrylate, 2-ethyl-2-adamantanyl (meth)acrylate, 2-isopropyladamantan-2-yl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, (adamantan-1-yloxy)methyl (meth)acrylate, 2-isopropyl-2-adamantyl (meth)acrylate, 1-methyl-1-ethyl-1-adamantylmethanol (meth)acrylate, 1,1-diethyl-1-adamantylmethanol (meth)acrylate, 2-cyclohexylpropan-2-yl (meth)acrylate, 1 Mono(meth)acrylates of polyhydric alcohols such as isopropylcyclohexyl(meth)acrylate, 1-methylcyclohexyl(meth)acrylate, 1-ethylcyclopentyl(meth)acrylate, 1-methylcyclohexyl(meth)acrylate, tetrahydropyranyl(meth)acrylate, tetrahydro-2-furanyl(meth)acrylate, 2-oxotetrahydrofuran-3-yl(meth)acrylate, (5-oxotetrahydrofuran-2-yl)methyl(meth)acrylate, (2-oxo-1,3-dioxolan-4-yl)methyl(meth)acrylate, and 1-ethoxyethyl(meth)acrylate. These may be used alone or in combination of two or more. The monofunctional (meth)acrylate compound preferably includes one having a molecular weight of 100 to 400, more preferably 120 to 380, further preferably 140 to 360, and particularly preferably 160 to 340.

[0029] (C) Epoxy resin The curable resin composition of the present invention contains an epoxy resin. The epoxy resin used in the present invention is a compound containing one or more epoxy groups that react with the thiol groups in the polyfunctional thiol compound. Normally, epoxy groups and thiol groups do not react under UV irradiation, but they can react under heat. Therefore, normally, epoxy resins do not react with polyfunctional thiol compounds under UV irradiation, but when a thermal curing accelerator (particularly a basic component) is present in the system or on the surface of the adherend, only the epoxy groups can react with the polyfunctional thiol compound under heat.

[0030] Epoxy resins are broadly classified into monofunctional epoxy resins and polyfunctional epoxy resins. An epoxy resin may contain only one of these, or may contain both. From the viewpoint of thermosetting properties, it is preferable that the epoxy resin contains a polyfunctional epoxy resin. It is particularly preferable that the epoxy resin contains a difunctional epoxy resin. In some embodiments, it is preferable that the epoxy resin is liquid at 25°C. In this specification, "liquid epoxy resin" refers to an epoxy resin that is in a liquid physical state at 25°C.

[0031] Monofunctional epoxy resins are epoxy resins containing one epoxy group. Examples of monofunctional epoxy resins include, but are not limited to, n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, ps-butylphenyl glycidyl ether, styrene oxide, α-pinene oxide, 4-tert-butylphenyl glycidyl ether, neodecanoic acid glycidyl ester, and 2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctanoic acid glycidyl ester. These may be used alone or in combination of two or more.

[0032] A multifunctional epoxy resin is an epoxy resin containing two or more epoxy groups. Multifunctional epoxy resins are broadly classified into aliphatic multifunctional epoxy resins and aromatic multifunctional epoxy resins. Aliphatic multifunctional epoxy resins are multifunctional epoxy resins that have a structure that does not contain an aromatic ring. Examples of aliphatic multifunctional epoxy resins include: diepoxy resins such as (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether, butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, polytetramethylene ether glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,2-epoxy-4-(2-methyloxiranyl)-1-methylcyclohexane, cyclohexane-type diglycidyl ether, and dicyclopentadiene-type diglycidyl ether; - Triepoxy resins such as trimethylolpropane triglycidyl ether, glycerin triglycidyl ether; -alicyclic epoxy resins such as vinyl(3,4-cyclohexene) dioxide and 2-(3,4-epoxycyclohexyl)-5,1-spiro-(3,4-epoxycyclohexyl)-m-dioxane; - glycidylamine type epoxy resins such as tetraglycidylbis(aminomethyl)cyclohexane; hydantoin-type epoxy resins, such as 1,3-diglycidyl-5-methyl-5-ethylhydantoin; and Epoxy resins with a silicone backbone, such as 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane These may be used alone or in combination of two or more.

[0033] Aromatic polyfunctional epoxy resins are polyfunctional epoxy resins that have a structure containing aromatic rings. Many of the epoxy resins that have been commonly used in the past, such as bisphenol A epoxy resins, are of this type. Examples of aromatic polyfunctional epoxy resins include: -bisphenol A epoxy resin; - Branched polyfunctional bisphenol A type epoxy resins such as p-glycidyloxyphenyldimethyltrisbisphenol A diglycidyl ether; -Bisphenol F type epoxy resin; -Novolac type epoxy resins; -Tetrabromobisphenol A type epoxy resin; -fluorene-type epoxy resins; -biphenyl aralkyl epoxy resins; -diepoxy resins such as 1,4-phenyldimethanol diglycidyl ether; -biphenyl-type epoxy resins such as 3,3',5,5'-tetramethyl-4,4'-diglycidyloxybiphenyl; -glycidylamine-based epoxy resins such as diglycidylaniline, diglycidyltoluidine, triglycidyl-p-aminophenol, and tetraglycidyl-m-xylylenediamine; and -Naphthalene ring-containing epoxy resin These may be used alone or in combination of two or more. The epoxy equivalent of the epoxy resin is preferably 90 to 500 g / eq, more preferably 100 to 450 g / eq, and even more preferably 100 to 350 g / eq.

[0034] (D) Polyfunctional thiol compounds The curable resin composition of the present invention contains a polyfunctional thiol compound. The polyfunctional thiol compound used in the present invention is a compound containing two or more thiol groups that react with the (meth)acryloyl groups (more precisely, the double bonds therein) in the polyfunctional (meth)acrylate compound and the monofunctional (meth)acrylate compound, and the epoxy groups in the epoxy resin. The polyfunctional thiol compound preferably contains three or more thiol groups. The polyfunctional thiol compound more preferably contains a trifunctional thiol compound and / or a tetrafunctional thiol compound. The trifunctional and tetrafunctional thiol compounds refer to thiol compounds having three and four thiol groups, respectively. The thiol equivalent of the polyfunctional thiol compound is preferably 90 to 150 g / eq, more preferably 90 to 140 g / eq, and even more preferably 90 to 130 g / eq.

[0035] Polyfunctional thiol compounds are broadly classified into thiol compounds that have a hydrolyzable partial structure such as an ester bond in the molecule (i.e., hydrolyzable) and thiol compounds that do not have such a partial structure (i.e., non-hydrolyzable). Examples of hydrolyzable polyfunctional thiol compounds include trimethylolpropane tris(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: TMMP), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate (manufactured by SC Organic Chemical Co., Ltd.: TEMPIC), pentaerythritol tetrakis(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: PEMP), and tetraethylene glycol bis(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: PEMP). Examples of suitable mercaptobutyrates include dipentaerythritol hexakis(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: EGMP-4), dipentaerythritol hexakis(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: DPMP), pentaerythritol tetrakis(3-mercaptobutyrate) (manufactured by Showa Denko K.K.: KarenzMT (registered trademark) PE1), and 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (manufactured by Showa Denko K.K.: KarenzMT (registered trademark) NR1). These may be used alone or in combination of two or more.

[0036] On the other hand, examples of non-hydrolyzable polyfunctional thiol compounds include 1,3,4,6-tetrakis(2-mercaptoethyl)glycoluril (manufactured by Shikoku Chemical Industry Co., Ltd.: TS-G), 1,3,4,6-tetrakis(3-mercaptopropyl)glycoluril (manufactured by Shikoku Chemical Industry Co., Ltd.: C3 TS-G), 1,3,4,6-tetrakis(mercaptomethyl)glycoluril, 1,3,4,6-tetrakis(mercaptomethyl)-3a-methylglycoluril, 1,3,4,6-tetrakis(2-mercaptoethyl)-3a-methylglycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl)-3a-methylglycoluril, 1,3,4,6-tetrakis(mercaptomethyl)-3a,6a-dimethylglycoluril, and 1,3,4,6-tetrakis(mercaptomethyl)-3a,6a-dimethylglycoluril. Tetrakis(2-mercaptoethyl)-3a,6a-dimethylglycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl)-3a,6a-dimethylglycoluril, 1,3,4,6-tetrakis(mercaptomethyl)-3a,6a-diphenylglycoluril, 1,3,4,6-tetrakis(2-mercaptoethyl)-3a,6a-diphenylglycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl)-3a,6a-diphenylglycoluril Choleuril, pentaerythritol tripropanethiol (manufactured by SC Organic Chemical Co., Ltd.: PEPT), pentaerythritol tetrapropanethiol, 1,2,3-tris(mercaptomethylthio)propane, 1,2,3-tris(2-mercaptoethylthio)propane, 1,2,3-tris(3-mercaptopropylthio)propane, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 5,7-dimercaptomethyl-1,11-dimercapto-3 ,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, tetrakis(mercaptomethylthiomethyl)methane, tetrakis(2-mercaptoethylthiomethyl)methane, tetrakis(3-mercaptopropylthiomethyl)methane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 1,1,2,2-Tetrakis(mercaptomethylthio)ethane, 1,1,5,5-tetrakis(mercaptomethylthio)-3-thiapentane, 1,1,6,6-tetrakis(mercaptomethylthio)-3,4-dithiahexane, 2,2-bis(mercaptomethylthio)ethanethiol, 3-mercaptomethylthio-1,7-dimercapto-2,6-dithiaheptane, 3,6-bis(mercaptomethylthio)-1,9-dimercapto-2,5,8-trithianonane, 3-mercaptomethylthio-1,6-dimercapto-2,5-dithiahexane, 1,1,9,9-tetrakis(mercaptomethylthio)ethanethiol kis(mercaptomethylthio)-5-(3,3-bis(mercaptomethylthio)-1-thiapropyl)3,7-dithianonane, tris(2,2-bis(mercaptomethylthio)ethyl)methane, tris(4,4-bis(mercaptomethylthio)-2-thiabutyl)methane, tetrakis(2,2-bis(mercaptomethylthio)ethyl)methane, tetrakis(4,4-bis(mercaptomethylthio)-2-thiabutyl)methane, 3,5,9,11-tetrakis(mercaptomethylthio)-1,13-dimercapto-2,6,8,12-tetrathiatridecane, 3,5,9,11,15,17-Hexakis(mercaptomethylthio)-1,19-dimercapto-2,6,8,12,14,18-hexathianonadecane, 9-(2,2-bis(mercaptomethylthio)ethyl)-3,5,13,15-tetrakis(mercaptomethylthio)-1,17-dimercapto-2,6,8,10,12,16-hexathiaheptadecane, 3,4,8,9-Tetrakis(mercaptomethylthio)-1,11-dimercapto-2,5,7,10-tetrathiaundecane, 3,4,8,9,13,14-Hexakis(mercaptomethylthio) thio)-1,16-dimercapto-2,5,7,10,12,15-hexathiahexadecane, 8-[bis(mercaptomethylthio)methyl]-3,4,12,13-tetrakis(mercaptomethylthio)-1,15-dimercapto-2,5,7,9,11,14-hexathiapentadecane, 4,6-bis[3,5-bis(mercaptomethylthio)-7-mercapto-2,6-dithiaheptylthio]-1,3-dithiane, 4-[3,5-bis(mercaptomethylthio)-7-mercapto-2,6-dithiaheptylthio]-6-mercaptomethylthio-1,3-Dithiane, 1,1-bis[4-(6-mercaptomethylthio)-1,3-dithianylthio]-1,3-bis(mercaptomethylthio)propane, 1-[4-(6-mercaptomethylthio)-1,3-dithianylthio]-3-[2,2-bis(mercaptomethylthio)ethyl]-7,9-bis(mercaptomethylthio)-2,4,6,10-tetrathiaundecane, 3-[2-(1,3-dithietanyl)]methyl-7,9-bis(mercaptomethylthio)-1,11-dimercapto-2,4,6,10-tetrathiaundecane, 9-[2-(1,3-di Thietanyl)]methyl-3,5,13,15-tetrakis(mercaptomethylthio)-1,17-dimercapto-2,6,8,10,12,16-hexathiaheptadecane, 3-[2-(1,3-dithietanyl)]methyl-7,9,13,15-tetrakis(mercaptomethylthio)-1,17-dimercapto-2,4,6,10,12,16-hexathiaheptadecane, 4,6-bis[4-(6-mercaptomethylthio)-1,3-dithianylthio]-6-[4-(6-mercaptomethylthio)-1,3-dithianylthio]-1,3-dithiane, 4-[3 ,4,8,9-tetrakis(mercaptomethylthio)-11-mercapto-2,5,7,10-tetrathiaundecyl]-5-mercaptomethylthio-1,3-dithiolane, 4,5-bis[3,4-bis(mercaptomethylthio)-6-mercapto-2,5-dithiahexylthio]-1,3-dithiolane, 4-[3,4-bis(mercaptomethylthio)-6-mercapto-2,5-dithiahexylthio]-5-mercaptomethylthio-1,3-dithiolane, 4-[3-bis(mercaptomethylthio)methyl-5,6-bis(mercaptomethylthio)-8-methyl mercapto-2,4,7-trithiaoctyl]-5-mercaptomethylthio-1,3-dithiolane, 2-{bis[3,4-bis(mercaptomethylthio)-6-mercapto-2,5-dithiahexylthio]methyl}-1,3-dithietane, 2-[3,4-bis(mercaptomethylthio)-6-mercapto-2,5-dithiahexylthio]mercaptomethylthiomethyl-1,3-dithietane, 2-[3,4,8,9-tetrakis(mercaptomethylthio)-11-mercapto-2,5,7,10-tetrathiaundecylthio]mercaptomethylthiomethyl-1,Examples include 3-dithietane, 2-[3-bis(mercaptomethylthio)methyl-5,6-bis(mercaptomethylthio)-8-mercapto-2,4,7-trithiaoctyl]mercaptomethylthiomethyl-1,3-dithietane, 4-{1-[2-(1,3-dithietanyl)]-3-mercapto-2-thiapropylthio}-5-[1,2-bis(mercaptomethylthio)-4-mercapto-3-thiabutylthio]-1,3-dithiolane, etc. These may be used alone or in combination of two or more.

[0037] In the curable resin composition of the present invention, the total number (total amount) of (meth)acryloyl groups contained in the (A) polyfunctional (meth)acrylate compound, the total number (total amount) of (meth)acryloyl groups contained in the (B) monofunctional (meth)acrylate compound, the total number (total amount) of epoxy groups contained in the (C) epoxy resin, and The total number (total amount) of thiol groups contained in the (D) polyfunctional thiol compound It is necessary that the following relationship be satisfied. Specifically, in the curable resin composition of the present invention, [the total number of (meth)acryloyl groups in the (B) monofunctional (meth)acrylate compound+the total number of epoxy groups in the (C) epoxy resin] / [the total number of thiol groups in the (D) polyfunctional thiol compound] is 0.1 to 0.5, [(B) the total number of (meth)acryloyl groups in the monofunctional (meth)acrylate compound] / [(D) the total number of thiol groups in the polyfunctional thiol compound] is 0.05 to 0.45, [(C) Total number of epoxy groups in the epoxy resin] / [(D) Total number of thiol groups in the polyfunctional thiol compound] is 0.05 to 0.45.

[0038] The total number of (meth)acryloyl groups in a polyfunctional (meth)acrylate compound is the quotient obtained by dividing the mass (g) of the polyfunctional (meth)acrylate compound contained in the polyfunctional (meth)acrylate compound by the (meth)acryloyl equivalent of that polyfunctional (meth)acrylate compound (if multiple types of polyfunctional (meth)acrylate compounds are contained, the sum of such quotients for each polyfunctional (meth)acrylate compound). The (meth)acryloyl equivalent is calculated as the quotient obtained by dividing the molecular weight of the polyfunctional (meth)acrylate compound by the number of (meth)acryloyl groups in one molecule of that polyfunctional (meth)acrylate compound. The total number of (meth)acryloyl groups in a monofunctional (meth)acrylate compound can be determined in the same manner as in a polyfunctional (meth)acrylate compound.

[0039] The curable resin composition of the present invention preferably contains a polyfunctional (meth)acrylate compound having a (meth)acryloyl equivalent of 60 to 300 g / eq, more preferably a polyfunctional (meth)acrylate compound having a (meth)acryloyl equivalent of 70 to 250 g / eq, and particularly preferably a polyfunctional (meth)acrylate compound having a (meth)acryloyl equivalent of 80 to 220 g / eq. The ratio of the total number of (meth)acryloyl groups in the (A) polyfunctional (meth)acrylate compound having a (meth)acryloyl equivalent of 300 g / eq or less to the total number of (meth)acryloyl groups in all the (A) polyfunctional (meth)acrylate compounds is preferably 0.7 to 1, more preferably 0.8 to 1, even more preferably 0.9 to 1, and particularly preferably 0.95 to 1. When the (A) polyfunctional (meth)acrylate compound having a (meth)acryloyl equivalent of 300 g / eq or less accounts for the majority of the (A) polyfunctional (meth)acrylate compound, the curable resin composition of the present invention tends to have good curability, and the composition tends to provide a cured product with a strong crosslinked structure, which is preferable.

[0040] Preferably, the polyfunctional (meth)acrylate compound (A) having a (meth)acryloyl equivalent of 300 g / eq or less does not have a poly(alkylene glycol) skeleton. In one embodiment of the present invention, the curable resin composition of the present invention contains a polyfunctional (meth)acrylate compound (A) having a (meth)acryloyl equivalent of 60 to 300 g / eq and not having a poly(alkylene glycol) skeleton. In this case, the cured product obtained from this composition is more likely to be imparted with adhesion to an adherend (as a result, the peel strength of the cured product is more likely to be improved). In this specification, the term "poly(alkylene glycol) backbone" refers to a poly(oxyalkylene) chain consisting of two or more oxyalkylene groups, such as a poly(oxyethylene) chain that can be introduced by ethylene oxide (EO) modification, or a poly(oxypropylene) chain that can be introduced by propylene oxide (PO) modification.

[0041] In contrast, it is not preferable for the above-mentioned polyfunctional (meth)acrylate compound (A) having a (meth)acryloyl equivalent of 300 g / eq or less to have a poly(alkylene glycol) skeleton, because if the curable resin composition of the present invention contains such a polyfunctional (meth)acrylate compound (A), the cured product obtained from the composition is unlikely to be imparted with sufficient adhesion to the adherend, and the peel strength of the cured product is likely to decrease. The curable resin composition of the present invention may contain (A) a polyfunctional (meth)acrylate compound having a (meth)acryloyl equivalent of 60 to 300 g / eq and a poly(alkylene glycol) skeleton. However, from the viewpoint of adhesion reliability, the ratio (total number of (meth)acryloyl groups in (A) a polyfunctional (meth)acrylate compound having a (meth)acryloyl equivalent of 60 to 300 g / eq and a poly(alkylene glycol) skeleton) / (total number of (meth)acryloyl groups in all (A) a polyfunctional (meth)acrylate compounds) is preferably 0.5 or less, more preferably 0.4 or less, even more preferably 0.3 or less, particularly preferably 0.2 or less, and most preferably 0.1 or less. In one embodiment of the present invention, this ratio is 0 to 0.5, preferably 0 to 0.4, more preferably 0 to 0.3, particularly preferably 0 to 0.2, and most preferably 0 to 0.1.

[0042] The total number of epoxy groups in an epoxy resin is the quotient obtained by dividing the mass (g) of the epoxy resin by the epoxy equivalent of that epoxy resin (if multiple types of epoxy resins are contained, the sum of such quotients for each epoxy resin). The epoxy equivalent can be determined by the method described in JIS K7236. If the epoxy equivalent cannot be determined by this method, it can also be calculated as the quotient obtained by dividing the molecular weight of the epoxy resin by the number of epoxy groups in one molecule of that epoxy resin.

[0043] The total number of thiol groups in a polyfunctional thiol compound is the quotient obtained by dividing the mass (g) of the polyfunctional thiol compound contained in the polyfunctional thiol compound by the thiol equivalent of the polyfunctional thiol compound (if multiple polyfunctional thiol compounds are contained, the sum of such quotients for each polyfunctional thiol compound). The thiol equivalent can be determined by iodometric titration. This method is widely known and is disclosed, for example, in paragraph 0079 of JP 2012-153794 A. If the thiol equivalent cannot be determined by this method, it may be calculated as the quotient obtained by dividing the molecular weight of the polyfunctional thiol compound by the number of thiol groups in one molecule of the polyfunctional thiol compound.

[0044] In conventional UV-thermosetting adhesives that do not contain monofunctional (meth)acrylate compounds or epoxy resins, the amount of the polyfunctional (meth)acrylate compound is approximately equivalent to the amount of the polyfunctional thiol compound. In contrast, the curable resin composition of the present invention contains a polyfunctional (meth)acrylate compound, a monofunctional (meth)acrylate compound, an epoxy resin, and a polyfunctional thiol compound in such quantitative ratios that the total number of (meth)acryloyl groups in the polyfunctional (meth)acrylate compound, the total number of (meth)acryloyl groups in the monofunctional (meth)acrylate compound, the total number of epoxy groups in the epoxy resin, and the total number of thiol groups in the polyfunctional thiol compound satisfy the above conditions.

[0045] If the ratio [(B) monofunctional (meth)acrylate compound (total number of (meth)acryloyloxy groups + (C) epoxy resin (total number of thiol groups)] / ((D) polyfunctional thiol compound (total number of thiol groups)] is greater than 0.5, component (B) will react with the thiol groups of component (D) to destroy crosslinking points, and the amount of component (C) that does not react with UV will increase, resulting in insufficient shear strength during UV curing. On the other hand, if the ratio [(B) monofunctional (meth)acrylate compound (total number of (meth)acryloyloxy groups + (C) epoxy resin (total number of thiol groups)] / ((D) polyfunctional thiol compound (total number of thiol groups)] is less than 0.1, the peel strength during UV curing will be insufficient, and the cured product will easily peel from the adherend.

[0046] In the present invention, [total number of (meth)acryloyloxy groups in (B) monofunctional (meth)acrylate compounds + total number of epoxy groups in (C) epoxy resins] / [total number of thiol groups in (D) polyfunctional thiol compounds] is preferably 0.25 to 0.5, and more preferably 0.3 to 0.45.

[0047] If the ratio [(B) monofunctional (meth)acrylate compound total number of (meth)acryloyl groups] / [(D) polyfunctional thiol compound total number of thiol groups] is less than 0.05, it is difficult to achieve a low crosslink density, and peel strength during UV curing tends to be low. On the other hand, if the ratio [(B) monofunctional (meth)acrylate compound total number of (meth)acryloyl groups] / [(D) polyfunctional thiol compound total number of thiol groups] is more than 0.45, crosslink density tends to be low, and shear strength during heat curing and peel strength during UV curing may be low.

[0048] In the present invention, [total number of (meth)acryloyl groups in (B) monofunctional acrylate compounds] / [total number of thiol groups in (D) polyfunctional thiol compounds] is preferably 0.1 to 0.4, more preferably 0.15 to 0.4, and even more preferably 0.15 to 0.35.

[0049] The epoxy resin (C) is used together with the component (B) and contributes to the development of peel strength after UV curing and shear strength after heat curing. In the present invention, the ratio of [total number of epoxy groups in the epoxy resin (C)] / [total number of thiol groups in the polyfunctional thiol compound (D)] is preferably 0.05 to 0.40, more preferably 0.05 to 0.35, and even more preferably 0.05 to 0.20. The ratio of the total number of (meth)acryloyl groups in the (B) monofunctional acrylate compound to the total number of epoxy groups in the (C) epoxy resin is preferably 1:0.01 to 1:20, more preferably 1:0.05 to 1:15, even more preferably 1:0.1 to 1:10, particularly preferably 1:0.1 to 1:5, and most preferably 1:0.1 to 1:1. If the ratio of the total number of (meth)acryloyl groups in the (B) monofunctional acrylate compound to the total number of epoxy groups in the (C) epoxy resin is too low, adhesion after UV curing and subsequent heat curing tends to be insufficient. On the other hand, if the ratio of the total number of (meth)acryloyloxy groups in the (B) monofunctional acrylate compound to the total number of epoxy groups in the (C) epoxy resin is too high, adhesion after UV curing tends to be insufficient.

[0050] In the curable resin composition of the present invention, it is preferable that the total amount of the polyfunctional (meth)acrylate compound, the monofunctional (meth)acrylate compound, and the epoxy resin is approximately equivalent to the amount of the polyfunctional thiol compound. In one embodiment of the present invention, the ratio [(A) total number of (meth)acryloyl groups in polyfunctional (meth)acrylate compounds] + (B) total number of (meth)acryloyl groups in monofunctional (meth)acrylate compounds + (C) total number of epoxy groups in epoxy resins] / (D) total number of thiol groups in polyfunctional thiol compounds] is preferably 0.8 to 1.2. If the ratio [(A) total number of (meth)acryloyl groups in polyfunctional (meth)acrylate compounds] + (B) total number of (meth)acryloyl groups in monofunctional (meth)acrylate compounds + (C) total number of epoxy groups in epoxy resins] / (D) total number of thiol groups in polyfunctional thiol compounds] is less than 0.8, the shear strength during UV curing tends to be low. On the other hand, if the ratio of [(A) total number of (meth)acryloyl groups in polyfunctional (meth)acrylate compounds] + (B) total number of (meth)acryloyl groups in monofunctional (meth)acrylate compounds + (C) total number of epoxy groups in epoxy resins] / [(D) total number of thiol groups in polyfunctional thiol compounds] exceeds 1.2, the shear strength during thermal curing in areas not exposed to UV rays tends to be low.

[0051] In the present invention, [total number of (meth)acryloyl groups in (A) polyfunctional (meth)acrylate compounds] + total number of (meth)acryloyl groups in (B) monofunctional (meth)acrylate compounds + total number of epoxy groups in (C) epoxy resins] / [total number of thiol groups in (D) polyfunctional thiol compounds] is preferably 0.8 to 1.2, more preferably 0.9 to 1.1, and even more preferably 0.95 to 1.1. When this range is 0.8 to 1.2, the number of unreacted groups is reduced, resulting in suitable properties of the resulting cured product.

[0052] In the present invention, the ratio [total number of (meth)acryloyl groups in (A) polyfunctional (meth)acrylate compound] / [total number of thiol groups in (D) polyfunctional thiol compound] is preferably 0.4 to 0.9, more preferably 0.4 to 0.8, and even more preferably 0.5 to 0.7. When this range is 0.4 to 0.9, the adhesive reliability after UV curing is likely to be improved.

[0053] (E) Photoradical initiator The curable resin composition of the present invention contains a photoradical initiator. By including a photoradical initiator, the curable resin composition can be provisionally cured by short-term UV irradiation. The photoradical initiator that can be used in the present invention is not particularly limited, and known photoradical initiators can be used. Examples of photoradical initiators include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, diethoxyacetophenone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, and the like. -on , benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin phenyl ether, benzil dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, methylphenyl glyoxylate, benzil, camphorquinone, etc. These may be used alone or in combination of two or more. The amount of (E) the photoradical initiator is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.1 to 3 mass % of the curable resin composition.

[0054] (F) Heat curing accelerator The curable resin composition of the present invention contains a thermal curing accelerator. By including the thermal curing accelerator, the curable resin composition of the present invention can be cured in a short time even under low-temperature conditions. The thermal curing accelerator used in the present invention is not particularly limited, and known thermal curing accelerators can be used. In one embodiment of the present invention, the thermal curing accelerator is a basic substance. The thermal curing accelerator is preferably a latent curing catalyst. A latent curing catalyst is a compound that is inactive at room temperature but is activated by heating to function as a curing catalyst. Examples of the latent curing catalyst include imidazole compounds that are solid at room temperature; solid-dispersed amine adduct latent curing catalysts such as reaction products of amine compounds and epoxy compounds (amine-epoxy adducts); and reaction products of amine compounds and isocyanate compounds or urea compounds (urea adducts).

[0055] Representative examples of commercially available latent curing catalysts include amine-epoxy adducts (amine adducts), such as "Amicure PN-23" (trade name, manufactured by Ajinomoto Fine-Techno Co., Ltd.), "Amicure PN-40" (trade name, manufactured by Ajinomoto Fine-Techno Co., Ltd.), "Amicure PN-50" (trade name, manufactured by Ajinomoto Fine-Techno Co., Ltd.), "Novacure HX-3742" (trade name, manufactured by Asahi Kasei Corporation), and "Novacure HX-3721" (trade name, manufactured by Asahi Kasei Corporation). Examples of suitable curing accelerators include "Novacure HXA9322HP" (trade name, manufactured by Asahi Kasei Corporation), "Novacure HXA3922HP" (trade name, manufactured by Asahi Kasei Corporation), "Novacure HXA3932HP" (trade name, manufactured by Asahi Kasei Corporation), "Novacure HXA5945HP" (trade name, manufactured by Asahi Kasei Corporation), "Novacure HXA9382HP" (trade name, manufactured by Asahi Kasei Corporation), and "Fujicure FXR1121" (trade name, manufactured by T&K TOKA Corporation). Urea adducts include "Fujicure FXE-1000" (trade name, manufactured by T&K TOKA Corporation) and "Fujicure FXR-1030" (trade name, manufactured by T&K TOKA Corporation), but are not limited thereto. The thermal curing accelerator may be used alone or in combination of two or more types. From the viewpoints of pot life and curability, the heat curing accelerator is preferably a solid dispersion type amine adduct latent curing catalyst. The amount of the heat curing accelerator is preferably 0.1 to 20 mass %, more preferably 0.5 to 15 mass %, and even more preferably 1 to 10 mass %, of the curable resin composition.

[0056] Some thermal curing accelerators are provided in the form of a dispersion in a polyfunctional epoxy resin. When such a thermal curing accelerator is used, it should be noted that the amount of the polyfunctional epoxy resin in which it is dispersed is also included in the amount of the epoxy resin in the curable resin composition of the present invention.

[0057] As mentioned above, conventional UV-thermosetting adhesives have a problem in that the peel strength of the bonded area is insufficient after UV curing. This problem is particularly likely to occur when the adherend has relatively low adhesion to the UV-thermosetting adhesive (e.g., an adherend made of polyethylene terephthalate (PET) or polybutylene terephthalate (PBT)). As a result of extensive investigations, the present inventors have found that the use of a monofunctional (meth)acrylate compound and an epoxy resin can improve the insufficient peel strength of the adhesive bonded portion in a UV-cured state, while also maintaining the shear strength.

[0058] The curable resin composition of the present invention is - UV curing, and / or -Heat curing treatment (thermal curing treatment) When both the UV curing treatment and the heat curing treatment are carried out, the treatment may be a two-stage treatment in which the heat curing treatment is carried out after the UV curing treatment. Under UV irradiation for the UV curing treatment, the following reactions (1) and (2) occur: (1) Addition of a thiol group to the double bond in a (meth)acryloyl group by radical reaction (2) Radical polymerization of the double bond in the (meth)acryloyl group (homopolymerization) The reaction of the epoxy group does not occur under UV irradiation.

[0059] On the other hand, under heating for the above-mentioned heat curing treatment, the following reactions (3) and (4): (3) Thermal addition of a thiol group to the double bond in the (meth)acryloyl group (4) Ring-opening nucleophilic addition of a thiol group to an epoxy group Radical polymerization (homopolymerization) of the double bond in the (meth)acryloyl group does not occur under heat.

[0060] When a polyfunctional (meth)acrylate compound and a polyfunctional thiol compound are subjected to the above-mentioned UV curing treatment and heat curing treatment in the presence of a photoradical initiator and a heat curing accelerator, - the reaction between a polyfunctional (meth)acrylate compound and a polyfunctional thiol compound (1), - a reaction between a polyfunctional (meth)acrylate compound (2), and -Reaction between polyfunctional (meth)acrylate compounds and polyfunctional thiol compounds (3) happens.

[0061] On the other hand, when the curable resin composition of the present invention is subjected to the UV curing treatment and the heat curing treatment, in addition to the above reactions, the following occurs: - the reaction between a monofunctional (meth)acrylate compound and a polyfunctional thiol compound (1), - a reaction between a polyfunctional (meth)acrylate compound and a monofunctional (meth)acrylate compound (2), - the reaction between monofunctional (meth)acrylate compounds (2), - the reaction between a monofunctional (meth)acrylate compound and a polyfunctional thiol compound (3), and -Reaction between epoxy resin and polyfunctional thiol compounds (4) happens.

[0062] Among these reactions in the presence of a monofunctional (meth)acrylate compound and an epoxy resin, reaction (1) between a monofunctional (meth)acrylate compound and a polyfunctional thiol compound, reaction (3) between a monofunctional (meth)acrylate compound and a polyfunctional thiol compound, and reaction (2) between a polyfunctional (meth)acrylate compound and a monofunctional (meth)acrylate compound suppress an increase in crosslink density of the cured product. Reactions (1) and (3) cap the thiol groups contained in the polyfunctional thiol compound, suppressing the formation of new crosslinks. Reaction (2) extends the polymer chain, increasing the spacing between crosslinks. The cured product obtained from the curable resin composition of the present invention is a polymer containing crosslinks. However, as described above, the use of a monofunctional (meth)acrylate compound and an epoxy resin prevents an increase in crosslink density during UV curing and heat curing. Therefore, this polymer has a lower crosslink density than cured products obtained from conventional curable resin compositions that do not use a monofunctional (meth)acrylate compound or an epoxy resin.

[0063] On the other hand, the reaction (4) between the epoxy resin and the polyfunctional thiol compound causes ring-opening of the epoxy group contained in the epoxy resin, generating hydroxyl groups, which can contribute to improving the adhesive strength of the cured product to the substrate and thus preventing peeling of the cured product from the substrate. Furthermore, if the epoxy resin is a monofunctional epoxy resin, reaction (4) caps the thiol groups contained in the polyfunctional thiol compound, suppressing the formation of new crosslinks. As a result, reaction (4) does not increase the crosslink density of the cured product. On the other hand, if the epoxy resin is a polyfunctional epoxy resin, reaction (4) could theoretically form new crosslinks. However, in reality, the UV curing process forms a polymer, restricting the movement of the epoxy resin within the system, making it difficult for new crosslinks to form.

[0064] The cured product obtained from the curable resin composition of the present invention has a lower crosslink density than the cured product obtained from conventional UV-thermosetting adhesives. This low crosslink density of the cured product is thought to contribute to the improvement of adhesive strength, particularly peel strength, after UV irradiation when the curable resin composition of the present invention is used as an adhesive. A portion of the peel stress applied to two parts bonded via the cured adhesive is dissipated by deformation of the cured product. The cured product of the curable resin composition of the present invention has a lower crosslink density and is more flexible than the cured products of conventional UV-thermosetting adhesives, so it is more easily deformed by peel stress. This is thought to result in greater dissipation of the peel stress and improved peel strength after UV irradiation.

[0065] On the other hand, shear stress is another important stress that may cause peeling and / or displacement of parts due to the impact described above. As the crosslink density (flexibility) of the cured product of an adhesive decreases, the shear strength of the bonded portion formed by the adhesive tends to decrease. In fact, the shear strength of the bonded portion formed by the curable resin composition of the present invention after UV irradiation may be lower than that of the bonded portion formed by a conventional UV-thermosetting adhesive. However, in relation to the flexibility of the cured product provided by the curable resin composition of the present invention, this shear strength is sufficient to prevent peeling and / or displacement of parts due to impact that may occur under normal conditions. Furthermore, the curable resin composition of the present invention has excellent adhesive strength (shear strength) even when subjected to heat treatment alone, and is therefore particularly useful when the area in contact with the adherend of the cured product obtained by UV irradiation is small.

[0066] If desired, the curable composition of the present invention may contain optional components other than the above components (A) to (F), such as those described below, as needed.

[0067] Fillers The curable resin composition of the present invention may contain a filler, particularly a silica filler and / or a talc filler, if desired. The filler can be added to improve the thermal cycle resistance of the cured product obtained by curing the curable resin composition of the present invention. The reason why the thermal cycle resistance is improved by adding a filler is that the linear expansion coefficient of the cured product is reduced, i.e., the expansion and contraction of the cured product due to thermal cycling is suppressed. Shrinkage during curing is also suppressed.

[0068] When a filler is used, its average particle size is preferably 0.1 to 10 μm. In this specification, unless otherwise specified, the average particle size refers to the volume-based median diameter (d50) measured by laser diffraction in accordance with ISO-13320 (2009).

[0069] When a filler is used, the content thereof is preferably 1 to 70 mass %, more preferably 5 to 60 mass %, relative to the total mass of the curable resin composition.

[0070] The filler may be used alone or in combination of two or more. Specific examples of fillers other than silica filler and talc filler include, but are not limited to, alumina filler, calcium carbonate filler, polytetrafluoroethylene (PTFE) filler, silicone filler, acrylic filler, styrene filler, etc. In the present invention, the filler may be surface-treated.

[0071] Stabilizers The curable resin composition of the present invention may contain a stabilizer if desired. The stabilizer can be added to the curable resin composition of the present invention to improve its storage stability and extend its pot life. Various stabilizers known as stabilizers for one-component adhesives can be used, but at least one selected from the group consisting of liquid borate ester compounds, aluminum chelates, and organic acids is preferred because of its high effect of improving storage stability.

[0072] Examples of liquid boric acid ester compounds include 2,2'-oxybis(5,5'-dimethyl-1,3,2-oxaborinane), trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, tripentyl borate, triallyl borate, trihexyl borate, tricyclohexyl borate, trioctyl borate, trinonyl borate, tridecyl borate, tridodecyl borate, trihexadecyl borate, trioctadecyl borate, tris(2-ethylhexyloxy)borane, bis(1,4,7,10-tetraoxaundecyl)(1,4,7,10,13-pentaoxatetradecyl)(1,4,7-trioxaundecyl)borane, tribenzyl borate, triphenyl borate, tri-o-tolyl borate, tri-m-tolyl borate, and triethanolamine borate. Liquid boric acid ester compounds are preferred because they are liquid at room temperature (25°C), which allows the viscosity of the formulation to be kept low. As the aluminum chelate, for example, Aluminum Chelate A (manufactured by Kawaken Fine Chemical Co., Ltd.) can be used. As the organic acid, for example, barbituric acid can be used.

[0073] When the curable resin composition of the present invention contains a stabilizer, the amount of the stabilizer is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass, per 100 parts by mass of the total amount of components (A) to (F).

[0074] Coupling agents The curable resin composition of the present invention may contain a coupling agent if desired. The addition of a coupling agent, particularly a silane coupling agent, is preferred from the viewpoint of improving adhesive strength. Silane coupling agents are organosilicon compounds having two or more different functional groups in their molecules, including a functional group capable of chemically bonding with inorganic materials and a functional group capable of chemically bonding with organic materials. Generally, the functional group capable of chemically bonding with inorganic materials is a hydrolyzable silyl group, and alkoxy groups, particularly silyl groups containing methoxy and / or ethoxy groups, are used as this functional group. Examples of functional groups capable of chemically bonding with organic materials include vinyl groups, epoxy groups, (meth)acrylic groups, styryl groups, unsubstituted or substituted amino groups, mercapto groups, ureido groups, and isocyanate groups. Various silane coupling agents having the above-mentioned functional groups can be used as coupling agents. Specific examples of silane coupling agents include 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, vinyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, and 3-isocyanatepropyltriethoxysilane. These silane coupling agents may be used alone or in combination of two or more. Note that silane coupling agents (including those used for the surface treatment of the above-mentioned fillers) may have reactive functional groups such as (meth)acryloyl groups, epoxy groups, etc. However, in the present invention, silane coupling agents are not included in components (A) to (F).

[0075] When the curable resin composition of the present invention contains a coupling agent, the amount of the coupling agent is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the total amount of components (A) to (F), from the viewpoint of improving adhesive strength.

[0076] Thixotropic agents The curable resin composition of the present invention may contain a thixotropic agent if desired. The thixotropic agent used in the present invention is not particularly limited, and known thixotropic agents can be used. Examples of thixotropic agents used in the present invention include, but are not limited to, silica. The silica may be natural silica (such as silica stone or quartz) or synthetic silica. The synthetic silica can be synthesized by any method, including a dry method and a wet method. The thixotropic agent may be surface-treated with a surface treatment agent (e.g., polydimethylsiloxane). In the present invention, it is preferable that at least a part of the thixotropic agent is surface-treated. The average particle size of the primary particles of the thixotropic agent is preferably 5 to 50 nm.

[0077] The curable resin composition of the present invention preferably contains 0.1 to 30 wt %, more preferably 1 to 20 wt %, and particularly preferably 1 to 15 wt % of the thixotropic agent relative to the total mass of the curable resin composition.

[0078] Other additives If desired, the curable resin composition of the present invention may contain other additives, such as carbon black, titanium black, an ion trapping agent, a leveling agent, an antioxidant, an antifoaming agent, a viscosity modifier, a flame retardant, a colorant, a solvent, etc. The type and amount of each additive are as per usual, provided that the addition does not impair the spirit and scope of the present invention.

[0079] The method for producing the curable resin composition of the present invention is not particularly limited. For example, the curable resin composition of the present invention can be obtained by simultaneously or separately introducing components (A) to (F) and, if desired, additives into an appropriate mixer, stirring and mixing while melting by heating if necessary, to form a homogeneous composition. The mixer is not particularly limited, but examples that can be used include a Raikai mixer equipped with a stirrer and a heater, a Henschel mixer, a three-roll mill, a ball mill, a planetary mixer, and a bead mill. These devices may also be used in appropriate combination.

[0080] The curable resin composition thus obtained can be converted into a cured product by subjecting it to UV curing treatment and / or heat curing treatment, as described above.

[0081] UV curing can be carried out by exposing the curable resin composition of the present invention to a sufficient cumulative amount of ultraviolet light at room temperature. The irradiation intensity is 100 to 10,000 mW / cm. 2 It is preferable that the intensity is 1000 to 9000 mW / cm 2 The wavelength of the ultraviolet light is preferably 315 to 450 nm, more preferably 340 to 430 nm, and particularly preferably 350 to 380 nm. The light source of the ultraviolet light is not particularly limited, and a gallium nitride UV-LED or the like can be used. The cumulative light amount of the ultraviolet light received by the curable resin composition of the present invention is preferably 200 mJ / cm. 2 or more, more preferably 500 mJ / cm 2 More preferably, 1000 mJ / cm 2 or more, and particularly preferably 2000 mJ / cm 2That's all. There is no particular limit to the upper limit of the cumulative light amount, and it can be freely set within a range that does not impair the spirit of the present invention. The cumulative light amount of ultraviolet light can be measured using measuring devices commonly used in the relevant field, such as an ultraviolet integrating actinometer and a photoreceiver. For example, the cumulative light amount in the ultraviolet wavelength range (310 to 390 nm) with a center wavelength of 365 nm can be measured using an ultraviolet integrating actinometer (UIT-250, manufactured by Ushio Inc.) and a photoreceiver (UVD-S365, manufactured by Ushio Inc.).

[0082] On the other hand, thermal curing can be carried out by heating the UV-cured curable resin composition of the present invention under appropriate conditions. This heating is preferably carried out at 60 to 120°C, more preferably at 60 to 100°C, and particularly preferably at 70 to 90°C. This heating is also preferably carried out for 5 to 180 minutes, more preferably at 10 to 120 minutes, and particularly preferably at 20 to 70 minutes.

[0083] When two parts (adherends) are bonded using the curable resin composition of the present invention by UV irradiation, peeling and / or misalignment of the parts is unlikely to occur even when peel stress is applied to the resulting assembly. This is because the flexibility of the cured product with a low crosslink density makes it easier for the peel stress to dissipate. The curable resin composition of the present invention exhibits sufficient adhesive strength not only when subjected to the two-stage curing treatment described above, but also when subjected to a thermal curing treatment alone. Furthermore, when subjected to a two-stage curing treatment, the curable resin composition of the present invention gives a cured product with a low crosslink density and flexibility.

[0084] The curable resin composition of the present invention can be used, for example, in semiconductor devices including various electronic components, as an adhesive for bonding components that constitute electronic components, or as a raw material thereof.

[0085] The present invention also provides an adhesive containing the curable resin composition of the present invention. The adhesive of the present invention is suitable for fixing modules, electronic components, etc. The present invention also provides a cured product obtained by curing the curable resin composition or adhesive of the present invention.The present invention also provides a semiconductor device including the cured product of the present invention.The present invention also provides a sensor module including the semiconductor device of the present invention. [Example]

[0086] The present invention will be described below with reference to examples, but is not limited to these. In the following examples, parts and % represent parts by mass and % by mass unless otherwise specified.

[0087] Examples 1 to 23, Comparative Examples 1 to 10 Curable resin compositions were prepared by mixing predetermined amounts of each component using a three-roll mill according to the formulation shown in Table 1. In Table 1, the amount of each component is expressed in parts by mass (unit: g).

[0088] (A) Polyfunctional (meth)acrylate compound In the examples and comparative examples, the compounds used as the polyfunctional (meth)acrylate compounds are as follows. (A-1): Dimethyloltricyclodecane diacrylate (trade name: Light Acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd., (meth)acrylate equivalent: 152) (A-2): 2-(2-acryloyloxy-1,1-dimethylethyl)-5-acryloyloxymethyl-5-ethyl-1,3-dioxane (trade name: KAYARAD R-604, manufactured by Nippon Kayaku Co., Ltd., (meth)acrylate equivalent: 163) (A-3): Polyether-based urethane acrylate (product name: UN-6200, manufactured by Negami Chemical Industrial Co., Ltd., (meth)acrylate equivalent: 3250) (A-4): Ditrimethylolpropane tetraacrylate (trade name: EBECRYL 140, manufactured by Daicel-Allnex Corporation, (meth)acrylate equivalent: 117)

[0089] (B) Monofunctional (meth)acrylate compound In the examples and comparative examples, the compounds used as the (B) monofunctional (meth)acrylate compound are as follows. (B-1): Isobornyl acrylate (trade name: Light Acrylate IBXA, manufactured by Kyoeisha Chemical Co., Ltd., (meth)acrylate equivalent: 208) (B-2): m-phenoxybenzyl acrylate (trade name: Light Acrylate POB-A, manufactured by Kyoeisha Chemical Co., Ltd., (meth)acrylate equivalent: 254) (B-3): 4-t-butylcyclohexyl acrylate (trade name: Kosylmer (registered trademark) TBCHA (registered trademark), manufactured by KJ Chemicals Co., Ltd., (meth)acrylate equivalent: 210) (B-4): Dicyclopentanyl acrylate (trade name: FA513AS, manufactured by Showa Denko Materials Co., Ltd., (meth)acrylate equivalent: 206) (B-5): 2-(o-phenylphenoxy)ethyl (meth)acrylate (trade name: HRD-01, manufactured by Nisshoku Techno Fine Chemical Co., Ltd., (meth)acrylate equivalent: 268)

[0090] (B') High molecular weight monofunctional (meth)acrylate compound In the examples and comparative examples, the compounds used as the (B') high molecular weight monofunctional (meth)acrylate compound are as follows. (B-1'): Methoxy-polyethylene glycol acrylate (trade name: Light Acrylate 130A, manufactured by Kyoeisha Chemical Co., Ltd., (meth)acrylate equivalent: 482)

[0091] (C) Epoxy resin In the examples and comparative examples, the compounds used as the epoxy resin (C) are as follows. (C-1): Bisphenol A epoxy resin (trade name: JER834, manufactured by Mitsubishi Chemical Holdings Corporation, epoxy equivalent: 250) (C-2): Dicyclopentadiene-type epoxy resin (trade name: EPICLON HP-7200L, manufactured by DIC Corporation, epoxy equivalent: 246) (C-3): Tri(epoxypentyl)isocyanurate (trade name: TEPIC-VL, manufactured by Nissan Chemical Industries, Ltd., epoxy equivalent: 135)

[0092] (D) Polyfunctional thiol compounds In the examples and comparative examples, the compounds used as the polyfunctional thiol compound (D) are as follows. (D-1): Pentaerythritol tetrakis(3-mercaptopropionate) (trade name: PEMP, manufactured by SC Organic Chemical Co., Ltd., thiol equivalent: 122) (D-2): Pentaerythritol trippropanethiol (trade name: PEPT, manufactured by SC Organic Chemical Co., Ltd., thiol equivalent: 124) (D-3): 1,3,4,6-tetrakis(3-mercaptopropyl)glycoluril (trade name: C3 TS-G, manufactured by Shikoku Chemicals Corporation, thiol equivalent: 114)

[0093] (E) Photoradical initiator (E-1): 1-hydroxycyclohexyl phenyl ketone (trade name: OMNIRAD 184, manufactured by IGM Resins BV) (E-2): 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO, manufactured by IGM Resins BV)

[0094] (F) Heat curing accelerator In the examples and comparative examples, the compounds used as the heat curing accelerator (F) are as follows: (F-1): Amine-epoxy adduct latent curing catalyst 1 (trade name: Fujicure FXR1121, manufactured by T&K TOKA Corporation) (F-2): Amine-epoxy adduct latent curing catalyst 2 (trade name: Amicure PN-23, manufactured by Ajinomoto Fine-Techno Co., Ltd.)

[0095] (G) Other additives (g1) Filler The compounds used as fillers in the examples and comparative examples are as follows: (G-1): Synthetic spherical silica (product name: SE2200SEE, manufactured by Admatechs Co., Ltd.) (G-2): Fine particle talc (product name: 5000PJ, manufactured by Matsumura Sangyo Co., Ltd.) (g2) stabilizer The compounds used as stabilizers in the examples and comparative examples are as follows: (G-3): N-nitroso-N-phenylhydroxylamine aluminum (Fujifilm Wako Pure Chemical Industries, Ltd.) (G-4): Triisopropyl borate (Tokyo Chemical Industry Co., Ltd.) (g3) Thixotropic agents The compounds used as thixotropic agents in the examples and comparative examples are as follows: (G-5): Fumed silica (trade name: CAB-O-SIL (registered trademark) TS-720, manufactured by Cabot Corporation, surface-treated with polydimethylsiloxane) The symbols in the "equivalent number calculation" in the table represent the following: [(A) + (B) + (C)] / (D): [(A) total number of (meth)acryloyl groups for polyfunctional (meth)acrylate compounds + (B) total number of (meth)acryloyl groups for monofunctional (meth)acrylate compounds + (C) total number of epoxy groups for epoxy resins] / [(D) total number of thiol groups for polyfunctional thiol compounds] (B) / (D): [(B) total number of (meth)acryloyl groups for monofunctional (meth)acrylate compounds] / [(D) total number of thiol groups for multifunctional thiol compounds] (C) / (D): [(C) Total number of epoxy groups for epoxy resin] / [(D) Total number of thiol groups for multifunctional thiol compound] [(B) + (C)] / (D): [(B) total number of (meth)acryloyl groups for monofunctional (meth)acrylate compounds + (C) total number of epoxy groups for epoxy resins] / [(D) total number of thiol groups for multifunctional thiol compounds] (A) / (D): [(A) total number of (meth)acryloyl groups in the multifunctional (meth)acrylate compound] / [(D) total number of thiol groups in the multifunctional thiol compound]

[0096] (Evaluation of peel strength after UV curing (90° peel test)) Using a JR2400N dispenser robot manufactured by Sanei Tech Co., Ltd., 0.1 g of the curable resin composition was applied to a 7.6 cm x 2.6 cm x 1.5 mm glass plate in three 5 cm long, closely spaced lines. A 12 cm x 1 cm x 0.15 mm polyimide film with a hole at one end was then placed on the applied curable resin composition, taking care to avoid air bubbles. The position of the polyimide film relative to the glass plate was adjusted so that the non-perforated short edge of the polyimide film was aligned with one short edge of the glass plate, and the line passing through the centers of both short edges of the polyimide film nearly overlapped with the line passing through the centers of both short edges of the glass plate. Then, a uniform force was applied from above the polyimide film, ensuring that the curable resin composition spread across the width of the polyimide film without spilling over the polyimide film or glass. The thickness of the curable resin composition at this point was approximately 0.2 mm. Thereafter, the curable resin composition was irradiated with a UV LED irradiation device AC475 manufactured by Excelitas Technologies, Inc. at an accumulated light dose of 2000 mJ / cm. 2 (Measured using a Ushio Inc. UIT-250 (with UVD-365 receiver connected)) The glass plate and polyimide film were bonded together by temporarily curing the film by irradiating it with UV light from the glass surface. The glass plate was fixed horizontally to a precision load measuring instrument (manufactured by Aiko Engineering, model number: 1605HTP), and the polyimide film adhered to the glass plate was connected to the precision load measuring instrument with a string tied to a hole provided in the polyimide film (at the end not adhered to the glass plate). A tensile load was applied to this polyimide film at a rate of 100 mm / min via the string using the precision load measuring instrument at 23° C. At this time, the position at which the glass plate was fixed was adjusted in advance so that the tensile load was applied to the polyimide film in the vertical direction at the point where the cured product (curable resin composition provisionally cured by UV irradiation) on the glass plate reached the position closest to the hole provided in the polyimide film. The change in tensile load was recorded from the start of application of the tensile load until the polyimide film was completely separated from the glass plate, and the maximum value of the tensile load was taken as the peel strength. The peel strength of each composition was the average of multiple measurements (n=4). The results are shown in Table 1. The peel strength after UV curing is preferably 1.7 N or more, and more preferably 2.0 N or more. When the measured peel strength was less than 1.7 N, it was evaluated as x, when the measured value was 1.7 N or more but less than 2.1 N, it was evaluated as o, and when the measured value was 2.1 N or more, it was evaluated as ⊚.

[0097] (Evaluation of shear strength after UV curing) The curable resin composition was printed onto a 3 cm x 4 cm x 0.1 mm stainless steel (SUS304) plate by stencil printing so as to form a 2 mm diameter circle. After printing, the composition had a diameter of 2 mm and a thickness of 0.1 mm. Alumina chips measuring 1.5 mm x 3 mm x 0.5 mm were placed on the printed curable resin composition, with the 1.5 mm x 3 mm surface facing downwards. The curable resin composition was exposed to UV light at an integrated light dose of 2000 mJ / cm using an Excelitas Technologies UV LED irradiation device AC475. 2 (Measured using a Ushio Inc. UIT-250 (with UVD-365 photoreceiver connected)) The alumina chips were bonded (temporarily fixed) to the stainless steel plate by subjecting them to a UV curing treatment through UV irradiation. After the UV curing process was completed, the shear strength (unit: N) of each bonded area was measured using a benchtop universal testing machine (1605HTP manufactured by Aiko Engineering Co., Ltd.). The shear strength measured by UV curing for each composition was the average of multiple measurements (n=10). The results are shown in Table 1. The shear strength after UV curing is preferably 15 N or more, and more preferably 20 N or more. When the measured shear strength after UV curing was less than 15 N, it was evaluated as x, when the measured value was 15 N or more but less than 20 N, it was evaluated as ◯, and when the measured value was 20 N or more, it was evaluated as ⊚.

[0098] (Evaluation of shear strength after heat curing) The curable resin composition (with alumina chips placed thereon) printed on a stainless steel plate as described in the above section "Evaluation of shear strength after UV curing" was subjected to a heat curing treatment by heating at 80°C for 60 minutes in an air dryer, thereby bonding the alumina chips to the stainless steel plate. After the heat curing process was completed, the shear strength (unit: N) of each bonded area was measured using a tabletop universal testing machine (1605HTP manufactured by Aiko Engineering Co., Ltd.). The shear strength after heat curing of each composition was the average of multiple measurements (n=10). The results are shown in Table 1. The shear strength after heat curing is preferably 30 N or more, and more preferably 50 N or more. When the measured shear strength after heat curing was less than 30 N, it was evaluated as x, when the measured value was 30 N or more but less than 50 N, it was evaluated as ◯, and when the measured value was 50 N or more, it was evaluated as ⊚.

[0099] (Evaluation of shear strength after UV+thermal curing) The same procedure as in the "Evaluation of shear strength after heat curing" above was repeated, except that a UV-cured product (whereby the alumina chips were bonded (temporarily fixed) to the stainless steel plate) obtained by UV curing treatment via UV irradiation as described in the "Evaluation of shear strength after heat curing" section above was used instead of the curable resin composition (on which alumina chips were placed) printed on the stainless steel plate. The shear strength of each composition after UV and heat curing was evaluated by calculating the average of multiple measurements (n=10). The shear strength after UV+thermal curing was sufficiently high for all of the compositions (Examples 1 to 23 and Comparative Examples 1 to 10), and was improved compared to the shear strength after UV curing.

[0100] [Table 1-1] [Table 1-2] [Table 1-3] [Table 1-4]

[0101] (Discussion of results) A composition that did not contain (B) a monofunctional (meth)acrylate compound and (C) an epoxy resin had insufficient peel strength after UV curing (Comparative Example 1). When the ratio [(B) monofunctional (meth)acrylate compound (total number of (meth)acryloyl groups) + (C) epoxy resin (total number of thiol groups)] / [(D) polyfunctional thiol compound (total number of thiol groups)] was less than 0.1, the peel strength after UV curing was insufficient (Comparative Example 2). On the other hand, when the ratio [(B) monofunctional (meth)acrylate compound (total number of (meth)acryloyl groups) + (C) epoxy resin (total number of thiol groups)] / [(D) polyfunctional thiol compound (total number of thiol groups)] was more than 0.5, the shear strength after UV curing was insufficient (Comparative Examples 3 to 5).

[0102] When the ratio [total number of (meth)acryloyl groups in (B) monofunctional (meth)acrylate compounds] / [total number of thiol groups in (D) polyfunctional thiol compounds] was less than 0.05, the shear strength after UV curing was insufficient (Comparative Example 6).On the other hand, when the ratio [total number of (meth)acryloyl groups in (B) monofunctional (meth)acrylate compounds] / [total number of thiol groups in (D) polyfunctional thiol compounds] was more than 0.45, the shear strength after thermal curing was insufficient (Comparative Example 7).

[0103] When the ratio of [total number of epoxy groups in (C) epoxy resin] / [total number of thiol groups in (D) polyfunctional thiol compound] was less than 0.05, the shear strength after thermal curing was insufficient (Comparative Example 8).On the other hand, when the ratio of [total number of epoxy groups in (C) epoxy resin] / [total number of thiol groups in (D) polyfunctional thiol compound] was more than 0.45, the shear strength after UV curing was insufficient (Comparative Example 9).

[0104] (B) In a composition containing a monofunctional (meth)acrylate compound having a molecular weight of more than 400 instead of the monofunctional (meth)acrylate compound, the shear strength after thermal curing was sufficient, but the peel strength and shear strength after UV curing were insufficient (Comparative Example 10). [Industrial Applicability]

[0105] The curable resin composition of the present invention exhibits sufficiently high adhesive strength even when subjected to either UV curing or thermal curing alone. Even when stress is applied to a final assembly in which components are bonded by UV curing and thermal curing of the curable resin composition of the present invention, or to an intermediate assembly in which components are temporarily fixed by UV curing and before thermal curing, separation and / or misalignment of components do not occur. Furthermore, the curable resin composition of the present invention enhances the adhesive reliability of the final product even when applied to a location where UV irradiation is not possible. Therefore, the curable resin composition of the present invention is extremely useful for bonding components of sensor modules, etc.

[0106] The disclosure of Japanese Patent Application No. 2021-116459 (filing date: July 14, 2021) is incorporated herein by reference in its entirety. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. The following (A) to (F): (A) Polyfunctional (meth)acrylate compound (B) Monofunctional (meth)acrylate compound having a molecular weight of 400 or less (C) Epoxy resin (D) Polyfunctional thiol compound (E) a photoradical initiator, and (F) Heat curing accelerator Including, [the total number of (meth)acryloyl groups in the (B) monofunctional (meth)acrylate compound + the total number of epoxy groups in the (C) epoxy resin] / [the total number of thiol groups in the (D) polyfunctional thiol compound] is 0.1 to 0.5, [(B) the total number of (meth)acryloyl groups in the monofunctional (meth)acrylate compound] / [(D) the total number of thiol groups in the polyfunctional thiol compound] is 0.05 to 0.45, [(C) the total number of epoxy groups in the epoxy resin] / [(D) the total number of thiol groups in the polyfunctional thiol compound] is 0.05 to 0.45, [(A) the total number of (meth)acryloyl groups in the polyfunctional (meth)acrylate compound] / [(D) the total number of thiol groups in the polyfunctional thiol compound] is 0.4 to 0.9, Curable resin composition.

2. The curable resin composition according to claim 1, wherein [the total number of (meth)acryloyl groups in the (B) monofunctional (meth)acrylate compound + the total number of epoxy groups in the (C) epoxy resin] / [the total number of thiol groups in the (D) polyfunctional thiol compound] is 0.3 to 0.

5.

3. The curable resin composition according to claim 1, wherein the polyfunctional thiol compound (D) has three or more thiol groups.

4. The curable resin composition according to claim 1, wherein the polyfunctional thiol compound (D) comprises a trifunctional thiol compound and / or a tetrafunctional thiol compound.

5. The curable resin composition according to claim 1, wherein the polyfunctional (meth)acrylate compound (A) comprises a difunctional (meth)acrylate compound.

6. An adhesive comprising the curable resin composition according to any one of claims 1 to 5.

7. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 5.

8. A semiconductor device comprising the cured product according to claim 7.

9. A sensor module comprising the cured product according to claim 7.

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