Curable resin composition

Abstract

The present invention addresses the problem of providing a curable resin composition which exhibits high curability even when subjected only to a heat-curing treatment and comes to have moderate flexibility and stretchability through a UV-curing treatment and a subsequent heat-curing treatment, and which gives cured objects having higher impact-absorbing ability than cured objects obtained from conventional adhesives of a UV / heat curing type. This curable resin composition comprises the following (A) to (E): (A) a urethane compound containing (meth)acryloyl groups, (B) a (meth)acrylate compound containing no urethane bond, (C) a polyfunctional thiol compound, (D) a radical photopolymerization initiator, and (E) a heat-curing accelerator. The total number (total amount) of (meth)acryloyl groups contained in the urethane compound (A) containing methacryloyl groups, the total number (total amount) of (meth)acryloyl groups contained in the (meth)acrylate compound (B) containing no urethane bond, and the total number (total amount) of thiol groups contained in the polyfunctional thiol compound (C) 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 crucial. Therefore, highly accurate positioning of each component is essential during assembly of image sensor modules. Using UV-thermosetting adhesives, components can be temporarily fixed by UV curing, preventing 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 the problem of insufficient adhesive reliability. When assembling components by bonding them together with UV-thermosetting adhesives, the components are bonded together through a curing process using ultraviolet (UV) light (UV curing) and a curing process using heat (thermosetting), and the assembly can be subjected to impacts such as being dropped. In such cases, with assemblies made using conventional UV-thermosetting adhesives, the bonded components (adherends) can partially or completely peel off.

[0006] Furthermore, 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 time the UV curing process is completed, some 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 area of ​​the UV-thermosetting adhesive that comes into contact with the adherend. For these reasons, a UV-thermosetting adhesive with excellent thermosetting properties has been desired.

[0007] 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 has excellent adhesive reliability, in which the adherend does not peel off even when subjected to an impact such as being dropped after UV curing treatment and thermosetting treatment, and that exhibits high curability even when subjected to thermosetting treatment alone. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention.

[0009] That is, the present invention includes, but is not limited to, the following inventions.

[0010] 1. (A) to (E) below: (A) a urethane compound containing a (meth)acryloyl group (B) A (meth)acrylate compound containing no urethane bond (C) Polyfunctional thiol compound (D) Photoradical initiator (E) Heat curing accelerator A curable resin composition comprising: (B) the (meth)acrylate compound contains a polyfunctional (meth)acrylate compound, [(A) the total number of (meth)acryloyl groups in the urethane compound] / [(C) the total number of thiol groups in the polyfunctional thiol compound]=0.001 to 0.2, A curable resin composition, wherein [(A) the total number of (meth)acryloyl groups in the urethane compound + (B) the total number of (meth)acryloyl groups in the (meth)acrylate compound] / [(C) the total number of thiol groups in the polyfunctional thiol compound]=0.5 to 1.3.

[0011] 2. The curable resin composition according to item 1 above, wherein the (meth)acrylate compound (B) further contains a monofunctional (meth)acrylate compound.

[0012] 3. Further containing (F) epoxy resin, [the total number of (meth)acryloyl groups for the (A) urethane compounds + the total number of (meth)acryloyl groups for the (B) (meth)acrylate compounds + the total number of epoxy groups for the (F) epoxy resins] / [the total number of thiol groups for the (C) polyfunctional thiol compounds]=0.5 to 1.3, 3. The curable resin composition according to item 1 or 2 above, wherein [total number of epoxy groups in the epoxy resin (F)] / [total number of thiol groups in the polyfunctional thiol compound (C)]<0.6.

[0013] 4. The curable resin composition according to any one of items 1 to 3 above, wherein the polyfunctional thiol compound (C) contains three or more thiol groups.

[0014] 5. The curable resin composition according to any one of items 1 to 4 above, wherein the (C) polyfunctional thiol compound includes a trifunctional thiol compound and / or a tetrafunctional thiol compound.

[0015] 6. The curable resin composition according to any one of items 1 to 5 above, wherein the urethane compound (A) includes a urethane compound containing two (meth)acryloyl groups.

[0016] 7. An adhesive comprising the curable resin composition according to any one of items 1 to 6 above.

[0017] 8. A cured product obtainable by curing the curable resin composition according to any one of the above items 1 to 6 or the adhesive according to the above item 7.

[0018] 9. A semiconductor device comprising the cured product according to item 8 above.

[0019] 10. A sensor module comprising the cured product described in the preceding item 8.

[0020] The curable resin composition of the present invention contains, as essential components, (A) a urethane compound containing a (meth)acryloyl group, (B) a (meth)acrylate compound not containing a urethane bond, (C) a polyfunctional thiol compound, (D) a photoradical initiator, and (E) a thermal 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.

[0021] 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."

[0022] (A) a urethane compound containing a (meth)acryloyl group The curable resin composition of the present invention contains (A) a urethane compound. The urethane compound of the present invention contains a (meth)acryloyl group in the molecule. The urethane compound means a compound containing one or more urethane bonds (—NH(C═O)O—). The urethane compound used in the present invention contains one or more (meth)acryloyl groups that react with thiol groups in the polyfunctional thiol compound described below. The (A) urethane compound preferably contains a (meth)acryloyl group in the form of a (meth)acryloyloxy group. A urethane compound containing a (meth)acryloyloxy group corresponds to a compound having a structure in which one molecule of a compound containing one or more urethane bonds and one or more hydroxyl groups is esterified with one or more molecules of (meth)acrylic acid (unesterified hydroxyl groups may also be present).

[0023] The (A) urethane compound may be used alone or in combination of two or more. In the present invention, the urethane compound containing a (meth)acryloyl group preferably contains two or more (meth)acryloyl groups, and more preferably contains two (meth)acryloyl groups.

[0024] Examples of urethane compounds containing one (meth)acryloyl group include 2-(butylcarbamoyloxy)ethyl (meth)acrylate, 2-(butylcarbamoyloxy)propyl (meth)acrylate, 4-(butylcarbamoyloxy)butyl (meth)acrylate, 2-(isopropylcarbamoyloxy)ethyl (meth)acrylate, 2-(isopropylcarbamoyloxy)propyl (meth)acrylate, 4-(isopropylcarbamoyloxy)butyl (meth)acrylate, 2-(phenylcarbamoyloxy)ethyl (meth)acrylate, 2-(phenylcarbamoyloxy)propyl (meth)acrylate, 4-(phenylcarbamoyloxy)butyl (meth)acrylate, 2-(benzylcarbamoyloxy)ethyl (meth)acrylate, 2-(benzylcarbamoyloxy)propyl (meth)acrylate, and 4-(benzylcarbamoyloxy)butyl (meth)acrylate.

[0025] A urethane compound containing two or more (meth)acryloyl groups can be obtained, for example, by reacting a polyisocyanate compound, a polyol compound, and a (meth)acrylate monomer having active hydrogen. In view of high impact absorption, preferred urethane compounds used in the present invention include urethane compounds having a polycarbonate or polyether main skeleton. These urethane compounds can be commercially purchased or can be produced by the methods described herein or other known methods in the art.

[0026] Examples of the polyisocyanate compound include aliphatic polyisocyanates, araliphatic polyisocyanates, and aromatic polyisocyanates. Among these, araliphatic polyisocyanates and alicyclic (aliphatic cyclic) polyisocyanates are preferred from the viewpoints of rigidity and moisture resistance.

[0027] Examples of aromatic aliphatic polyisocyanates include m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, etc. These may be used alone or in combination.

[0028] Examples of the alicyclic polyisocyanate include isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexylene-1,2-dicarboxylate, and 2,5- or 2,6-norbornane diisocyanate, which can be used alone or in combination.

[0029] Examples of the polyol compound include compounds having two or more active hydroxyl groups in the molecule, such as polyether diols, polyester diols, polyolefins, and polycarbonate diols, and specific examples include polyethylene diol, polypropylene diol, polytetramethylene ether glycol, adipate polyester polyol, polycaprolactone polyol, polycarbonate polyol, polybutadiene diol, hydrogenated polybutadiene diol, polyisoprene diol, and hydrogenated polyisoprene diol. These compounds can be used alone or in combination.

[0030] Examples of the (meth)acrylate monomer having active hydrogen include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, propylene glycol mono(meth)acrylate, 2-hydroxy-3-methoxypropyl (meth)acrylate, and pentaerythritol tri(meth)acrylate. Instead of the (meth)acrylate monomer having active hydrogen, its analogs, such as N-methylol (meth)acrylamide and N-hydroxy (meth)acrylamide, can also be used. These can be used alone or in combination.

[0031] From the viewpoint of the impact absorption properties imparted to the curable resin composition, the weight average molecular weight of the (A) urethane compound is preferably 500 to 50,000, more preferably 500 to 25,000, even more preferably 700 to 15,000, particularly preferably 1,000 to 10,000, and most preferably 2,000 to 10,000. The (meth)acrylate equivalent of the urethane compound of the present invention is preferably 250 to 12,500, more preferably 350 to 7,500, still more preferably 500 to 5,000, and particularly preferably 1,000 to 4,500.

[0032] The urethane compound used in the present invention imparts appropriate flexibility and extensibility to the cured product obtained by subjecting the curable resin composition of the present invention to a UV curing treatment and subsequent heat curing treatment. This flexibility and extensibility significantly improve the impact absorption capacity of the cured product. As a result, assemblies made using the curable resin composition of the present invention are prevented from peeling off of parts (adherends) even when subjected to impact, such as by being dropped.

[0033] However, urethane compounds generally have high viscosity. If the viscosity of this compound is too high, the ejection ability of the curable resin composition from a dispenser decreases. In the present invention, from the viewpoint of appropriate ejection ability of the curable resin composition, the urethane compound of the present invention preferably has a viscosity at 25°C of 0.5 Pa·s to 2000 Pa·s, more preferably 1 mPa·s to 500 Pa·s, even more preferably 1 Pa·s to 200 Pa·s, and particularly preferably 1 Pa·s to 100 Pa·s.

[0034] (B) A (meth)acrylate compound containing no urethane bond The curable resin composition of the present invention contains (B) a (meth)acrylate compound. The (meth)acrylate compound of the present invention does not contain a urethane bond in the molecule. The (meth)acrylate compound of the present invention is a compound containing one or more (meth)acryloyl groups in the form of (meth)acryloyloxy groups that react with thiol groups in a polyfunctional thiol compound described below. However, silane coupling agents containing a (meth)acryloyl group are not included in the (meth)acrylate compound of the present invention. Preferably, the (meth)acrylate compound of the present invention does not contain a silicon atom. The (meth)acrylate compound (B) may contain a (meth)acryloyl group that is not in the form of a (meth)acryloyloxy group, as long as it satisfies the above structural requirements. For example, N,N'-methylenebisacrylamide is not considered a polyfunctional (meth)acrylate compound.

[0035] (B) (meth)acrylate compound A polyfunctional (meth)acrylate compound, which is a compound containing two or more (meth)acryloyl groups in the form of (meth)acryloyloxy groups; and Monofunctional (meth)acrylate compounds, which are compounds containing one (meth)acryloyl group in the form of a (meth)acryloyloxy group. (B) (meth)acrylate compound includes a polyfunctional (meth)acrylate compound. In one embodiment of the present invention, (B) (meth)acrylate compound further includes a monofunctional (meth)acrylate compound.

[0036] 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 - neopentyl glycol modified trimethylolpropane di(meth)acrylate; -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; - polyesters containing two or more (meth)acryloyl groups in one molecule; -polyfunctional (meth)acrylates of glycerin; and the like. These may be EO- or PO-modified. Among these, di(meth)acrylate of dimethyloltricyclodecane, (tri / tetra)(meth)acrylate of ditrimethylolpropane, hexa(meth)acrylate of dipentaerythritol, and di(meth)acrylate of neopentyl glycol-modified trimethylolpropane 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.

[0037] In the present invention, the polyfunctional (meth)acrylate compound preferably includes a bifunctional (meth)acrylate compound. The bifunctional (meth)acrylate compound is a polyfunctional (meth)acrylate compound containing two (meth)acryloyl groups in the form of (meth)acryloyloxy groups. Similarly, the trifunctional and tetrafunctional (meth)acrylate compounds are polyfunctional (meth)acrylate compounds containing three and four (meth)acryloyl groups in the form of (meth)acryloyloxy groups, respectively. Of the (B) (meth)acrylate compounds, the molecular weight of the polyfunctional (meth)acrylate compound is, from the viewpoint of curability, preferably 150 to 700, more preferably 150 to 600, even more preferably 150 to 500, particularly preferably 180 to 495, and most preferably 200 to 490. When the polyfunctional (meth)acrylate compound is a polymer or contains multiple chemical species, the molecular weight of the polyfunctional (meth)acrylate compound represents the weight average molecular weight.

[0038] On the other hand, 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. Of the (B) (meth)acrylate compounds, the molecular weight of the monofunctional (meth)acrylate compound is, from the viewpoint of curability, preferably 100 to 400, more preferably 120 to 380, even more preferably 140 to 360, and particularly preferably 160 to 340. When the monofunctional (meth)acrylate compound is a polymer or contains multiple chemical species, the molecular weight of the monofunctional (meth)acrylate compound represents the weight average molecular weight.

[0039] When the (meth)acrylate compound of the present invention contains a monofunctional (meth)acrylate compound in addition to a polyfunctional (meth)acrylate compound, the thiol groups of the polyfunctional thiol compound are in excess relative to the (meth)acryloyl groups of the urethane compound and the polyfunctional (meth)acrylate compound. These excess thiol groups react with the (meth)acryloyl groups of the monofunctional (meth)acrylate compound under UV irradiation and / or heating. The reaction between the (meth)acryloyl groups of the monofunctional (meth)acrylate compound and the thiol groups does not result in crosslinking. As a result, the resulting cured product has a lower crosslink density than a cured product obtained from a curable resin composition that does not contain a monofunctional (meth)acrylate compound. This reduced crosslink density may improve the flexibility of the cured product and improve its physical properties. For example, the impact absorption capacity of the cured product may be further improved, making the cured product less likely to peel from an adherend. In addition, a monofunctional (meth)acrylate compound may be added to the curable resin composition of the present invention as a viscosity adjuster. As described above, the (A) urethane compound has a high viscosity, so when the curable resin composition of the present invention contains a monofunctional (meth)acrylate compound in addition to a polyfunctional (meth)acrylate compound, it becomes easy to make the dischargeability from a dispenser appropriate.

[0040] When the (meth)acrylate compound of the present invention contains a monofunctional (meth)acrylate compound in addition to a polyfunctional (meth)acrylate compound, the ratio [total number of (meth)acryloyl groups in the monofunctional (meth)acrylate compounds] / [total number of thiol groups in the (C) polyfunctional thiol compounds] is preferably 0.01 to 0.5, more preferably 0.1 to 0.4. When the ratio [total number of (meth)acryloyl groups in the monofunctional (meth)acrylate compounds] / [total number of thiol groups in the (C) polyfunctional thiol compounds] is within the above range, there are advantages such as further improved drop resistance of the cured product, reduced viscosity of the curable resin composition, and improved dischargeability. If [total number of (meth)acryloyl groups in monofunctional (meth)acrylate compounds] / [total number of thiol groups in (C) polyfunctional thiol compounds] is greater than 0.5, reactivity during UV and heat curing may be insufficient.

[0041] (C) Polyfunctional thiol compound The curable resin composition of the present invention contains (C) 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 urethane compound and the (meth)acrylate compound. 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. Trifunctional and tetrafunctional thiol compounds refer to thiol compounds containing three and four thiol groups, respectively.

[0042] 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.

[0043] 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.

[0044] In the curable resin composition of the present invention, the total number (total amount) of (meth)acryloyl groups contained in the urethane compound (A) containing a (meth)acryloyl group, the total number (total amount) of (meth)acryloyl groups contained in the (meth)acrylate compound (B) that does not contain a urethane bond, and The total number (total amount) of thiol groups contained in the (C) polyfunctional thiol compound It is necessary that the following relationship be satisfied. Specifically, in the curable resin composition of the present invention, [(A) the total number of (meth)acryloyl groups in the urethane compound] / [(C) the total number of thiol groups in the polyfunctional thiol compound]=0.001 to 0.2, [(A) total number of (meth)acryloyl groups in urethane compounds + (B) total number of (meth)acryloyl groups in (meth)acrylate compounds] / [(C) total number of thiol groups in polyfunctional thiol compounds]=0.5 to 1.3.

[0045] The total number of (meth)acryloyl groups in a urethane compound containing a (meth)acryloyl group is the quotient obtained by dividing the mass (g) of the urethane compound contained in the urethane compound by the (meth)acrylate equivalent of the urethane compound (if multiple types of urethane compounds are contained, the sum of such quotients for each urethane compound). The (meth)acrylate equivalent is calculated as the quotient obtained by dividing the molecular weight of the urethane compound by the number of (meth)acryloyl groups in one molecule of the urethane compound. The total number of (meth)acryloyl groups in a (meth)acrylate compound that does not contain a urethane bond can be determined in the same manner as in the case of the urethane compound.

[0046] 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.

[0047] If the ratio [total number of (meth)acryloyl groups in the (A) urethane compound] / [total number of thiol groups in the (C) polyfunctional thiol compound] is greater than 0.2, problems may arise such as poor dischargeability during dispensing and insufficient curing. On the other hand, if the ratio [total number of (meth)acryloyl groups in the (A) urethane compound] / [total number of thiol groups in the (C) polyfunctional thiol compound] is less than 0.001, the flexibility of the cured product will be insufficient, and the cured product will be prone to peeling from the adherend.

[0048] In the present invention, [total number of (meth)acryloyl groups in (A) urethane compound] / [total number of thiol groups in (C) polyfunctional thiol compound] is preferably 0.001 to 0.15, more preferably 0.001 to 0.125, and even more preferably 0.002 to 0.1.

[0049] If the ratio [(A) urethane compound (total number of (meth)acryloyl groups) + (B) (meth)acrylate compound (total number of thiol groups)] / [(C) polyfunctional thiol compound (total number of thiol groups)] is less than 0.5, the curability may be insufficient. On the other hand, if the ratio [(A) urethane compound (total number of (meth)acryloyl groups) + (B) (meth)acrylate compound (total number of thiol groups)] / [(C) polyfunctional thiol compound (total number of thiol groups)] is more than 1.3, the curability may be insufficient.

[0050] In the present invention, [total number of (meth)acryloyl groups in (A) urethane compounds + total number of (meth)acryloyl groups in (B) (meth)acrylate compounds] / [total number of thiol groups in (C) polyfunctional thiol compounds] is preferably 0.6 to 1.3, more preferably 0.7 to 1.2, even more preferably 0.8 to 1.2, and particularly preferably 0.9 to 1.1.

[0051] (D) Photoradical initiator The curable resin composition of the present invention contains a photoradical initiator. By using the photoradical initiator, it becomes possible to cure the curable resin composition 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.

[0052] (E) Heat curing accelerator The curable resin composition of the present invention contains a thermal curing accelerator. Use of the thermal curing accelerator allows the curable resin composition of the present invention to be cured in a short time even under low-temperature conditions. In one embodiment of the present invention, the thermal curing accelerator is a basic substance. The basic substance preferably contains a tertiary amine compound and / or an imidazole compound. Use of these basic substances can efficiently accelerate the curing reaction between a thiol group and a (meth)acryloyl group. 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 latent curing catalysts 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).

[0053] Representative examples of commercially available latent curing catalysts containing a tertiary amine compound and / or an imidazole compound include "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), "Novacure HX-3721" (trade name, manufactured by Asahi Kasei Corporation), "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 HXA9382HP" (trade name, manufactured by Asahi Kasei Corporation), and "Fujicure FXR1121" (trade name, manufactured by T&K Corporation). Examples of suitable heat-curing accelerators include, but are not limited to, "Fujicure FXE-1000" (trade name, manufactured by T&K TOKA Corporation), "Fujicure FXR-1020" (trade name, manufactured by T&K TOKA Corporation), and "Fujicure FXR-1030" (trade name, manufactured by T&K TOKA Corporation). The heat-curing accelerators may be used alone or in combination of two or more. From the viewpoints of pot life and curability, a solid-dispersion amine adduct-based latent curing catalyst is preferred as the heat-curing accelerator.

[0054] Some thermal curing accelerators are provided in the form of a dispersion in a polyfunctional epoxy resin. When a thermal curing accelerator in such a form is used, it should be noted that the amount of the polyfunctional epoxy resin in which it is dispersed is included in the amount of the epoxy resin, which is optionally contained in the curable resin composition of the present invention and will be described later.

[0055] Furthermore, from the viewpoint of appropriate dischargeability, the curable resin composition of the present invention preferably has a viscosity of 1 Pa·s to 100 Pa·s, more preferably 5 Pa·s to 90 Pa·s, even more preferably 10 Pa·s to 80 Pa·s, and particularly preferably 20 Pa·s to 70 Pa·s, when measured at 25° C. The viscosity can be measured, for example, using a Brookfield Digital Thermometer DV1 with a spindle SC4-14 at a rotation speed of 50 rpm.

[0056] If desired, the curable composition of the present invention may contain optional components other than the above components (A) to (E), such as the epoxy resins and additives described below, as needed.

[0057] (F) Epoxy resin The curable resin composition of the present invention may contain, if desired, an epoxy resin (F). The epoxy resin is a compound containing one or more epoxy groups that react with the thiol groups in the polyfunctional thiol compound. Generally, epoxy groups and thiol groups do not react under UV irradiation, but can react under heat.

[0058] Epoxy resins are broadly classified into monofunctional epoxy resins and polyfunctional epoxy resins, and the epoxy resin may contain only one of these or both of these.

[0059] 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.

[0060] 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.

[0061] 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, tetraglycidyl-m-xylylenediamine; and -Naphthalene ring-containing epoxy resin These may be used alone or in combination of two or more.

[0062] When the curable resin composition of the present invention contains an epoxy resin, [the total number of (meth)acryloyl groups for the (A) urethane compounds + the total number of (meth)acryloyl groups for the (B) (meth)acrylate compounds + the total number of epoxy groups for the (F) epoxy resins] / [the total number of thiol groups for the (C) polyfunctional thiol compounds]=0.5 to 1.3, It is preferable that [(F) the total number of epoxy groups in the epoxy resin] / [(C) the total number of thiol groups in the polyfunctional thiol compound]<0.6. Furthermore, when the curable resin composition of the present invention contains an epoxy resin, it is particularly preferable that [total number of epoxy groups in (F) epoxy resin] / [total number of thiol groups in (C) polyfunctional thiol compound]≧0.05. In one embodiment of the present invention, [total number of epoxy groups in (F) epoxy resin] / [total number of thiol groups in (C) polyfunctional thiol compound] is 0.05 to 0.6, preferably 0.2 to 0.4.

[0063] In the curable resin composition of the present invention, when the total number of (meth)acryloyl groups in the (A) urethane compound, the total number of (meth)acryloyl groups in the (B) (meth)acrylate compound, the total number of thiol groups in the (C) polyfunctional thiol compound, and the total number of epoxy groups in the (F) epoxy resin satisfy the above relationship, the thiol groups in the polyfunctional thiol compound are in excess relative to the (meth)acryloyl groups in the urethane compound and the (meth)acrylate compound. These excess thiol groups react with epoxy groups under heating. However, in reality, UV curing forms a polymer, restricting the movement of the epoxy resin within the system, so little crosslinking occurs in the reaction between the epoxy groups and the thiol groups. As a result, the resulting cured product has a lower crosslink density and is more flexible than cured products obtained from curable resin compositions that do not contain epoxy resins. This flexibility further improves the impact absorption capacity of the cured product and makes it less likely to peel from an adherend. Furthermore, the reaction between epoxy groups and thiol groups causes ring-opening of the epoxy groups in the epoxy resin, generating hydroxyl groups. The hydroxyl groups can contribute to improving the adhesive strength of the cured product to the adherend, and in turn, to preventing the cured product from peeling off from the adherend.

[0064] 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.

[0065] 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.

[0066] 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).

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] When a stabilizer is added, the amount added is preferably 0.01 to 30 parts by mass, more preferably 0.05 to 25 parts by mass, and even more preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of the total amount of the curable resin composition.

[0072] 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).

[0073] In the curable resin composition of the present invention, the amount of coupling agent added is preferably 0.01 to 50 parts by mass, and more preferably 0.1 to 30 parts by mass, per 100 parts by mass of the total amount of the curable resin composition, from the viewpoint of improving adhesive strength.

[0074] 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.

[0075] The curable resin composition of the present invention preferably contains 0.1 to 30 mass %, more preferably 1 to 20 mass %, and particularly preferably 1 to 15 mass % of the thixotropic agent relative to the total mass of the curable resin composition.

[0076] 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.

[0077] 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 (E) and, if desired, component (F) and additives into an appropriate mixer, and stirring and mixing them while melting them by heating if necessary to form a homogeneous composition. The mixer is not particularly limited, and 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.

[0078] The curable resin composition thus obtained is, as described above, UV curing, and / or - Heat hardening treatment (thermal hardening treatment) The cured product can be converted into a cured product by subjecting the cured product to a curing treatment including the steps of:

[0079] The UV curing treatment 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.).

[0080] 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.

[0081] The cured product obtained by subjecting the curable resin composition of the present invention to a UV curing treatment and subsequent heat curing treatment has improved flexibility and elongation compared to the cured product obtained with conventional UV-thermosetting adhesives, and accordingly, has significantly improved impact absorption. Therefore, even if an assembly made using the curable resin composition of the present invention is subjected to an unexpected impact, such as being dropped, peeling of the parts (adherends) is prevented. Furthermore, the curable resin composition of the present invention exhibits sufficient curability even when subjected to heat treatment alone to form a cured product. This property of the curable resin composition of the present invention contributes to further improving adhesion reliability, even when a UV curing treatment and subsequent heat curing treatment are performed. This is because even if there are portions of the curable resin composition that are not exposed to UV irradiation during the UV curing treatment, those portions will be sufficiently cured by the subsequent heat curing.

[0082] 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.

[0083] 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 obtainable by curing the curable resin composition or adhesive of the present invention by UV curing and / or thermal curing. Preferably, this cured product is prepared by subjecting the curable resin composition or adhesive to UV curing followed by thermal curing. The present invention also provides a semiconductor device comprising the cured product of the present invention. The present invention also provides a sensor module comprising the semiconductor device of the present invention. [Example]

[0084] 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.

[0085] Examples 1 to 20, Comparative Examples 1 to 4 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).

[0086] (A) a urethane compound containing a (meth)acryloyl group In the examples and comparative examples, the compounds used as the urethane compounds containing a (meth)acryloyl group are as follows. (A-1): Polyether-based urethane acrylate (product name: Art Resin UN6200, manufactured by Negami Chemical Industrial Co., Ltd., (meth)acrylate equivalent: 3250) (A-2): Adduct type urethane acrylate (product name: Art Resin UN-2601, manufactured by Negami Chemical Industrial Co., Ltd., (meth)acrylate equivalent: 800) (A-3): Soft urethane acrylate (product name: Shiko (registered trademark) UV-3000B, manufactured by Mitsubishi Chemical Corporation, (meth)acrylate equivalent: 9000) (A-4): Polycarbonate-based urethane acrylate (product name: UN-9200A, manufactured by Negami Chemical Industrial Co., Ltd., (meth)acrylate equivalent: 7500) (A-5): Soft urethane acrylate (product name: Shiko (registered trademark) UV-2000B, manufactured by Mitsubishi Chemical Corporation, (meth)acrylate equivalent: 6500) (A-6): Polycarbonate-based urethane acrylate (product name: UN-5590, manufactured by Negami Chemical Industrial Co., Ltd., (meth)acrylate equivalent: 4500)

[0087] (B) A (meth)acrylate compound containing no urethane bond In the examples and comparative examples, the compounds used as the (meth)acrylate compounds not containing a urethane bond are as follows. (b1) Polyfunctional (meth)acrylate compound (B-1): Dimethyloltricyclodecane diacrylate (trade name: Light Acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd., (meth)acrylate equivalent: 152) (B-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) (B-3): Ditrimethylolpropane tetraacrylate (trade name: EBECRYL 140, manufactured by Daicel-Allnex Corporation, (meth)acrylate equivalent: 110) (b2) Monofunctional (meth)acrylate compound (B-4): Isobornyl acrylate (trade name: Light Acrylate IBXA, manufactured by Kyoeisha Chemical Co., Ltd., (meth)acrylate equivalent: 208) (B-5): 4-t-butylcyclohexyl acrylate (trade name: Kosylmer (registered trademark) TBCHA (registered trademark), manufactured by KJ Chemicals Co., Ltd., (meth)acrylate equivalent: 198)

[0088] (C) Polyfunctional thiol compound In the examples and comparative examples, the compounds used as the polyfunctional thiol compound (C) are as follows. (C-1): Pentaerythritol tetrakis(3-mercaptopropionate) (trade name: PEMP, manufactured by SC Organic Chemical Co., Ltd., thiol equivalent: 122) (C-2): 1,3,4,6-tetrakis(3-mercaptopropyl)glycoluril (trade name: C3 TS-G, manufactured by Shikoku Chemicals Corporation, thiol equivalent: 114)

[0089] (D) Photoradical initiator (D-1): 1-hydroxycyclohexyl phenyl ketone (trade name: Omnirad 184, manufactured by IGM Resins BV) (D-2): 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO, manufactured by IGM Resins BV)

[0090] (E) Heat curing accelerator In the examples and comparative examples, the compounds used as the heat curing accelerator (E) are as follows: (E-1): Amine-epoxy adduct latent curing catalyst 1 (trade name: Fujicure FXR1121, manufactured by T&K TOKA Corporation) (E-2): Amine-epoxy adduct latent curing catalyst 2 (trade name: Amicure PN-23, manufactured by Ajinomoto Fine-Techno Co., Ltd.)

[0091] (F) Epoxy resin In the examples and comparative examples, the compounds used as the epoxy resin (F) are as follows: (F-1): Bisphenol A epoxy resin (product name: JER834, manufactured by Mitsubishi Chemical Holdings Corporation, epoxy equivalent: 250) (F-2): 1,4-cyclohexanedimethanol diglycidyl ether (trade name: Showfree (registered trademark) CDMDG, manufactured by Showa Denko K.K., epoxy equivalent: 136)

[0092] (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): Triisopropyl borate (Tokyo Chemical Industry Co., Ltd.) (G-4): N-nitroso-N-phenylhydroxylamine aluminum (manufactured by Fujifilm Wako Pure Chemical Industries, 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 following symbols in the table represent the following: [(A) + (b1) + (b2) + (F)] / (C): [(A) total number of (meth)acryloyl groups for urethane compounds + (b1) total number of (meth)acryloyl groups for polyfunctional (meth)acrylate compounds + (b2) total number of (meth)acryloyl groups for monofunctional (meth)acrylate compounds + (F) total number of epoxy groups for epoxy resins] / [(C) total number of thiol groups for polyfunctional thiol compounds] (A) / (C): [(A) total number of (meth)acryloyl groups in the urethane compound] / [(C) total number of thiol groups in the polyfunctional thiol compound] [(A) + (b1)] / (C): [(A) total number of (meth)acryloyl groups for urethane compounds + (b1) total number of (meth)acryloyl groups for polyfunctional (meth)acrylate compounds] / [(C) total number of thiol groups for polyfunctional thiol compounds] (b2) / (C): [(b2) total number of (meth)acryloyl groups for monofunctional (meth)acrylate compounds] / [(C) total number of thiol groups for polyfunctional thiol compounds] (F) / (C): [(F) total number of epoxy groups for epoxy resin] / [(C) total number of thiol groups for polyfunctional thiol compound]

[0093] (Evaluation of thermosetting properties) Two glass plates were each coated with a silicone-based release agent. Two rectangular parallelepiped polyimide spacers, each 0.3 mm high, were placed on the release-agent-coated surface of one of the glass plates, and a curable resin composition was applied between them. The other glass plate was placed on this glass plate with the release-agent-coated surface facing downwards, so that the curable resin composition and spacers were sandwiched between the two glass plates. The curable resin composition between the two glass plates was subjected to a heat curing treatment by heating at 80°C for 60 minutes in an air dryer. The thermosetting properties of the curable resin compositions were evaluated based on whether or not the curable resin composition formed a peelable film while maintaining its shape at the completion of the heat curing treatment. The symbol "◯" in the table indicates that the curable resin composition formed a peelable film while maintaining its shape at the completion of the heat curing treatment. The symbol "×" in the table indicates that the curable resin composition did not form a peelable film while maintaining its shape at the completion of the heat curing treatment.

[0094] (Drop resistance evaluation) The resin compositions that were rated "good" in the above (evaluation of thermosetting property) were evaluated for drop resistance as follows. A 2.5cm x 7.5cm x 2mm liquid crystal polymer (LAPEROS® E463i, manufactured by Polyplastics Co., Ltd.) plate (hereinafter referred to as "LCP plate") was printed with a 150µm thick polyimide film with 2mm diameter holes in eight locations using stencil printing to form a circular pattern with the curable resin composition. The printed composition had a diameter of 2mm and a thickness of 0.1mm. Eight alumina chips, each measuring 1.5mm x 3mm x 0.5mm, were placed on the printed curable resin composition with the 1.5mm x 0.5mm surface facing downwards. The curable resin composition was then irradiated with an Excelitas Technologies UV LED irradiation device AC475 at an integrated light dose of 2000mJ / cm. 2 The alumina chips were bonded to the LCP plate by UV curing treatment using UV irradiation (measured using a Ushio Inc. UIT-250 (connected to a UVD-365 receiver)), followed by a heat curing treatment by heating at 80°C for 60 minutes in a fan dryer.The LCP plate with the alumina chips bonded to it was used as a sample and subjected to a drop test using a fully automatic drop tester FIT-18 (manufactured by Hitachi Technology and Services Co., Ltd.) as follows.

[0095] The sample was fixed to a fixture (total weight 160 g) attached to the test apparatus so that it would not come off due to the impact of a drop, and this fixture was then set into the test apparatus. At this time, with the sample and fixture set into the test apparatus, the side of the sample with the alumina chips attached was placed facing up, and the LCP plate was placed horizontally to the ground. The sample was then forcibly dropped along with the fixture, thereby applying a drop impact to the sample. The test apparatus was appropriately set so that the sample's velocity immediately before impact was 5424 mm / s. The drop test was repeated for one sample until all eight attached alumina chips came off. The drop resistance was evaluated based on the number of drop tests required until all eight alumina chips were removed. If the number of drop tests was 5 or more, the drop resistance was evaluated as "good," and if the number of drop tests was less than 5, the drop resistance was evaluated as "poor." The results are shown in Table 1.

[0096] [Table 1-1] [Table 1-2] [Table 1-3]

[0097] (Discussion of results) As is clear from Table 1, parts (adherends) bonded by UV curing and heat curing using the curable resin compositions of Examples 1 to 20 containing appropriate amounts of (A) a urethane compound, (B) a (meth)acrylate compound, (C) a multifunctional thiol compound, (D) a photoradical initiator, and (E) a heat curing accelerator are unlikely to come off even when subjected to impact from being dropped. Furthermore, all of the curable resin compositions of Examples 1 to 20 were sufficiently cured even when subjected to heat curing alone. Furthermore, all of the curable resin compositions of Examples 1 to 20 were sufficiently cured even when subjected to the UV curing alone.

[0098] On the other hand, when a curable resin composition having a ratio of [total number of (meth)acryloyl groups in (A) urethane compound] / [total number of thiol groups in (C) polyfunctional thiol compound] of less than 0.001 is used and subjected to a UV curing treatment and a heat curing treatment, the component (adherend) comes off when subjected to an impact from being dropped (Comparative Example 1).When a curable resin composition having a ratio of [total number of (meth)acryloyl groups in (A) urethane compound] / [total number of thiol groups in (C) polyfunctional thiol compound] of more than 0.2 is subjected to a heat curing treatment alone, the component is not sufficiently cured (Comparative Example 2). Furthermore, when the curable resin composition is subjected to only a heat curing treatment, the ratio of [the total number of (meth)acryloyl groups in (A) urethane compounds + the total number of (meth)acryloyl groups in (B) (meth)acrylate compounds] / [the total number of thiol groups in (C) polyfunctional thiol compounds] is not within the range of 0.5 to 1.3, and the composition is not sufficiently cured (Comparative Examples 3 and 4). [Industrial Applicability]

[0099] The curable resin composition of the present invention, when subjected to a UV curing treatment and subsequent heat curing treatment, provides a cured product with appropriate flexibility and elongation, and with improved impact absorption compared to the cured products of conventional UV-thermosetting adhesives. Furthermore, the curable resin composition of the present invention exhibits high curability even when subjected to a heat curing treatment alone. As a result, the curable resin composition of the present invention has excellent adhesive reliability, and even if an assembly made using the composition is subjected to an impact, such as by being dropped, peeling of the components (adherends) is prevented. Therefore, the curable resin composition of the present invention is extremely useful for bonding components of sensor modules, etc.

[0100] The disclosure of Japanese Patent Application No. 2021-116461 (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 (E): (A) a urethane compound containing a (meth)acryloyl group (B) A (meth)acrylate compound containing no urethane bond (C) Polyfunctional thiol compound (D) Photoradical initiator (E) Heat curing accelerator A curable resin composition comprising: (B) the (meth)acrylate compound contains a polyfunctional (meth)acrylate compound, [(A) the total number of (meth)acryloyl groups in the urethane compound] / [(C) the total number of thiol groups in the polyfunctional thiol compound]=0.001 to 0.2, A curable resin composition, wherein [(A) total number of (meth)acryloyl groups for the urethane compound + (B) total number of (meth)acryloyl groups for the (meth)acrylate compound] / [(C) total number of thiol groups for the polyfunctional thiol compound]=0.7 to 1.

3.

2. The curable resin composition according to claim 1, wherein the (meth)acrylate compound (B) further comprises a monofunctional (meth)acrylate compound.

3. further comprising (F) an epoxy resin, [total number of (meth)acryloyl groups for (A) urethane compounds + total number of (meth)acryloyl groups for (B) (meth)acrylate compounds + total number of epoxy groups for (F) epoxy resins] / [total number of thiol groups for (C) polyfunctional thiol compounds]=0.5 to 1.3, The curable resin composition according to claim 1, wherein [(F) the total number of epoxy groups in the epoxy resin] / [(C) the total number of thiol groups in the polyfunctional thiol compound] is less than 0.

6.

4. further comprising (F) an epoxy resin, [total number of (meth)acryloyl groups for (A) urethane compounds + total number of (meth)acryloyl groups for (B) (meth)acrylate compounds + total number of epoxy groups for (F) epoxy resins] / [total number of thiol groups for (C) polyfunctional thiol compounds]=0.5 to 1.3, The curable resin composition according to claim 2, wherein [(F) the total number of epoxy groups in the epoxy resin] / [(C) the total number of thiol groups in the polyfunctional thiol compound] is less than 0.

6.

5. The curable resin composition according to claim 1, wherein the polyfunctional thiol compound (C) contains three or more thiol groups.

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

7. The curable resin composition according to claim 1, wherein the urethane compound (A) comprises a urethane compound containing two (meth)acryloyl groups.

8. An adhesive comprising the curable resin composition according to any one of claims 1 to 7.

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

10. A semiconductor device comprising the cured product according to claim 9.

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

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