Curing method for photocurable resin composition, bonding, sealing, and coating method using same, and cured product thereof

Abstract

The present invention addresses the problem of providing: a curing method for a photocurable resin composition under atmospheric conditions by using a photon up-conversion mechanism, which achieves both surface curability and curability in deep portions of the photocurable resin composition; a bonding, sealing, and coating method using the curing method; and a cured product thereof.　Provided are: a curing method for a photocurable resin composition, the method including a step for simultaneously or sequentially irradiating a photocurable resin composition that contains a polymerizable compound with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm, and polymerizing the polymerizable compound using at least a photon up-conversion mechanism under atmospheric conditions; a bonding, sealing, and coating method using the curing method; and a cured product thereof.

Description

Method for curing photocurable resin composition, adhesion, sealing and coating method using same, and cured product thereof

[0001] The present invention relates to a method for curing a photocurable resin composition, a bonding, sealing and coating method using the curing method, and a cured product thereof.

[0002] Adhesives that are temporarily fixed by ultraviolet (UV) irradiation and then fully cured by heat are used in many fields (e.g., Patent Documents 1 and 2). If the adhesive contains a filler or the like, the filler or the like may act as a shield against UV irradiation light, or if the area where the adhesive is applied has a complex shape, the UV irradiation light may be blocked, resulting in areas in the adhesive that are not reached by UV irradiation light. In such cases, those areas remain uncured, making it difficult to achieve the desired degree of cure. For this reason, this type of adhesive is used in applications where there are areas that are not reached by UV irradiation light and remain uncured, with the aim of fully curing by heat.

[0003] JP 2009-51954 A International Publication No. 2005 / 052021

[0004] On the other hand, from the viewpoint of improving productivity and taking into consideration the case where the composition is applied to heat-sensitive members, there is a demand for a photocurable resin composition that can be completely cured by light irradiation alone, without requiring main curing by heat.

[0005] The present inventors focused on photon upconversion materials capable of converting long-wavelength light into short-wavelength light. When irradiated with specific light, photon upconversion materials generate high-energy states through processes such as multiphoton excitation and triplet-triplet annihilation, and during the relaxation process, emit light with a shorter wavelength than the incident light. The present inventors hypothesized that by incorporating this photon upconversion material into a resin composition and irradiating the resin composition with long-wavelength light, the photon upconversion material would perform wavelength conversion within the resin composition, generating short-wavelength light and activating a photopolymerization initiator. After extensive investigation, they confirmed that photon upconversion emission actually activates the photopolymerization initiator, causing polymerization of a polymerizable compound in the resin composition, thereby promoting curing of the resin composition. Long-wavelength light has a longer penetration distance into a target object than high-energy short-wavelength light (e.g., 365 nm UV light). The present inventors have confirmed that irradiation with long-wavelength light causes photon upconversion emission, which allows curing of the resin composition to proceed even in places where UV irradiation is difficult to reach, and that curing is completed by light irradiation alone, eliminating the need for main curing by heat. Based on these findings, the present applicant filed Japanese Patent Application No. 2023-119225 (July 21, 2023) regarding a photocurable resin composition containing a photon upconversion material.

[0006] As a result of further investigation, the inventors have found that the wavelength conversion mechanism of photon upconversion is highly susceptible to polymerization inhibition by oxygen, and therefore when a resin composition containing a photon upconversion material is cured by irradiation with long-wavelength light under atmospheric conditions, the wavelength conversion of photon upconversion is inhibited by oxygen inhibition on the surface of the resin composition, resulting in poor curability of the surface of the resin composition. Curing under an inert gas atmosphere such as nitrogen to avoid oxygen inhibition imposes restrictions on how and where a photocurable resin composition containing a photon upconversion material can be used.

[0007] Therefore, an object of the present invention is to provide a method for curing a photocurable resin composition under atmospheric conditions using a photon upconversion mechanism, which allows both the surface curing and deep curing of the photocurable resin composition, a bonding, sealing and coating method using the curing method, and a cured product obtained by the method.

[0008] Specific means for solving the above problems are as follows. Aspects of the present invention include the following methods for curing a photocurable resin composition, bonding methods, sealing methods, and coating methods, as well as cured products obtained by the methods for curing a photocurable resin composition. [1] A method for curing a photocurable resin composition, comprising the steps of: irradiating a photocurable resin composition containing a polymerizable compound with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm, simultaneously or sequentially, under atmospheric conditions, and polymerizing the polymerizable compound using at least a photon upconversion mechanism. [2] A method for bonding at least two components using a photocurable resin composition, comprising: a step of applying a photocurable resin composition containing a polymerizable compound to at least one of the at least two components; a step of attaching the other component to the component coated with the photocurable resin composition via the photocurable resin composition, or a step of attaching the component coated with the photocurable resin composition to the other component via the photocurable resin composition; and a step of irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm simultaneously or sequentially under atmospheric conditions to polymerize the polymerizable compound using at least a photon upconversion mechanism. [3] A method for sealing gaps between or within components with a photocurable resin composition, comprising the steps of: applying or injecting a photocurable resin composition containing a polymerizable compound into the gaps between or within the components; and irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm, simultaneously or sequentially, under atmospheric conditions, to polymerize the polymerizable compound using at least a photon upconversion mechanism. [4] A method for coating a surface of an object with a photocurable resin composition, comprising the steps of applying a photocurable resin composition containing a polymerizable compound to the object; and irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm, simultaneously or sequentially, under atmospheric conditions, to polymerize the polymerizable compound using at least a photon upconversion mechanism. [5] The method according to any one of [1] to [4], wherein the photocurable resin composition contains a photon upconversion material.[6] The method according to [5], wherein the emission wavelength of the photon upconversion material includes a wavelength of 500 nm or less. [7] The method according to any one of [1] to [6], wherein the photocurable resin composition satisfies at least one of the following characteristics (a) and (b): (a) the polymerizable compound includes a maleimide compound; (b) the photocurable resin composition further includes a photopolymerization initiator. [8] The method according to any one of [2], [3], and [5] to [7], wherein the component is a component constituting a semiconductor device or an electronic component. [9] The method according to any one of [4] and [5] to [7], wherein the object is a semiconductor device or an electronic component, or a component constituting these.

[10] A cured product cured by the curing method according to any one of [1] and [5] to [7].

[0009] According to aspects of the present invention, there are provided a method for curing a photocurable resin composition under atmospheric conditions using a photon upconversion mechanism, which achieves both surface curability and deep curability of the photocurable resin composition, as well as an adhesion, sealing, and coating method using the curing method, and a cured product thereof.

[0010] As used herein, "ultraviolet light" refers to light with a wavelength of 200 nm to 380 nm, "visible light" refers to light with a wavelength of 380 nm to 780 nm, "near-infrared light" refers to light with a wavelength of 780 nm to 2500 nm, and "(mid) infrared light" refers to light with a wavelength of 2.5 μm to 25 μm. In this specification, following the convention in the field of synthetic resins, the term "resin," which normally refers to a polymer (particularly a synthetic polymer), may be used to refer to the components constituting a curable resin composition before curing, even when the component is not a polymer, for example, a prepolymer compound before curing. As used herein, the term "(meth)acryloyl group" includes both a methacryloyl group and an acryloyl group. Furthermore, the term "(meth)acrylate compound" includes both an acrylate compound and a methacrylate compound. Furthermore, in this specification, a "photocurable resin composition" may be simply referred to as a "resin composition."

[0011] [Method for curing photocurable resin composition] One embodiment of the present invention relates to a method for curing a photocurable resin composition, which includes the steps of simultaneously or sequentially irradiating a photocurable resin composition containing a polymerizable compound with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm under atmospheric conditions, and polymerizing the polymerizable compound using at least a photon upconversion mechanism. When curing the photocurable resin composition under atmospheric conditions using the photon upconversion mechanism, the photocurable resin composition is irradiated with light having a wavelength of 500 nm or less before, simultaneously with, or after curing the photocurable resin composition using the photon upconversion mechanism, thereby activating the polymerizable compound present near the surface of the photocurable resin composition and curing the surface of the photocurable resin composition. Long-wavelength light has a longer penetration distance into an object than high-energy short-wavelength light. Once the surface of a photocurable resin composition is cured by irradiation with light having a wavelength of 500 nm or less, light irradiated simultaneously or subsequently with light having a wavelength greater than 500 nm penetrates the interior (deep portion) of the resin composition and undergoes wavelength conversion by the photon upconversion mechanism without oxygen inhibition, causing polymerization of the polymerizable compound in the interior (deep portion) of the resin composition to cure the interior (deep portion) of the resin composition. Alternatively, the interior (deep portion) of the resin composition is cured by first irradiating it with light having a wavelength greater than 500 nm, and then the surface of the photocurable resin composition is cured by irradiating it with light having a wavelength of 500 nm or less. This provides a method for curing a photocurable resin composition under atmospheric conditions using the photon upconversion mechanism, which achieves both surface curability and deep curability of the photocurable resin composition.

[0012] A cured product obtained by the curing method of this embodiment is also one aspect of the present invention. This cured product has effectively cured surfaces and interiors (deep portions).

[0013] In the curing method of this embodiment, a photocurable resin composition containing a polymerizable compound is irradiated simultaneously or sequentially with light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm under atmospheric conditions. In this specification, "sequentially irradiating with light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm" includes "irradiating with light having a wavelength of 500 nm or less, and then irradiating with light having a wavelength exceeding 500 nm" and "irradiating with light having a wavelength exceeding 500 nm, and then irradiating with light having a wavelength of 500 nm or less." In one embodiment, light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm are irradiated simultaneously. In one embodiment, light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm are irradiated in this order. That is, in one embodiment, light having a wavelength of 500 nm or less is irradiated, and then light having a wavelength exceeding 500 nm is irradiated. In one embodiment, light having a wavelength exceeding 500 nm is irradiated, and then light having a wavelength of 500 nm is irradiated.

[0014] The wavelength of light having a wavelength of 500 nm or less may be, for example, 280 nm, 310 nm, 365 nm, 385 nm, 395 nm, or 405 nm, but is not limited to these wavelengths. The light source of light having a wavelength of 500 nm or less may be, for example, an LED, an LD module, a mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, or the like, but is not limited to these. The cumulative dose of light having a wavelength of 500 nm or less is 1 mJ / cm. ２ ~2000 J / cm ２ The irradiation intensity of light with a wavelength of 500 nm or less can be 1 mW / cm ２ ~1000 W / cm ２ The cumulative irradiation amount and irradiation intensity of the irradiated light can be adjusted appropriately depending on the desired degree of cure. In this embodiment, the irradiation with light having a wavelength of 500 nm or less can be performed as either spot irradiation, in which a localized region is irradiated with light, or area irradiation, in which a wide region is irradiated with light.

[0015] The wavelength of the irradiating light having a wavelength of more than 500 nm may be, for example, 532 nm, 650 nm, 940 nm, 980 nm, 1064 nm, or 1550 nm, but is not limited to these wavelengths. The light source of the irradiating light having a wavelength of more than 500 nm may be an LED, a laser, an LD module, or other coherent light source. The integrated irradiance of the light having a wavelength of more than 500 nm is 1 mJ / cm. ２ ~10,000J / cm ２ The irradiation intensity of light with a wavelength of more than 500 nm can be 1 mW / cm ２ ~1000 W / cm ２ The cumulative irradiation amount and irradiation intensity of the irradiated light can be adjusted appropriately depending on the desired degree of cure. In this embodiment, the irradiation with light having a wavelength of more than 500 nm can be performed as either spot irradiation, in which a localized region is irradiated with light, or area irradiation, in which a wide region is irradiated with light.

[0016] Photon upconversion (PUC) is a technology for converting low-energy (long-wavelength) light into high-energy (short-wavelength) light. Photon upconversion mechanisms include triplet-triplet annihilation (TTA), multi-photon excitation of rare-earth element-containing materials, and two-photon absorption. Any photon upconversion mechanism can be used in this embodiment, but a triplet-triplet annihilation type photon upconversion mechanism, a multi-photon excitation type photon upconversion mechanism, or a combination thereof is preferred. By using the photon upconversion mechanism, the polymerizable compound is activated by the converted high-energy (short-wavelength) light, and polymerization of the polymerizable compound proceeds.

[0017] Conventionally, high-energy, short-wavelength light (e.g., 365 nm UV light) is generally used to photo-cure UV-curable adhesives. Therefore, when the adhesive contains a filler or the like, the penetration distance of the light into the UV-curable adhesive is short when irradiated with short-wavelength light, and curing does not proceed in areas where the light cannot reach due to a shielding object or the like. Regarding the latter issue in particular, for example, when the shielding object is a silicon substrate and the relationship between the wavelength of irradiated light and the penetration distance of light in the silicon substrate is examined, ultraviolet light of 380 nm or less penetrates the silicon substrate by several to several tens of nanometers, whereas visible light of 380 to 780 nm penetrates by several hundred nanometers to several microns, and infrared light of 780 nm or more reaches by several tens of microns to the order of millimeters (see, for example, Optical Properties of Silicon, [online], PVEducation,<https: / / www.pveducation.org / pvcdrom / materials / optical-properties-of-silicon> reference).

[0018] The polymerizable compound used in the curing method of this embodiment can be appropriately selected from radically polymerizable compounds, cationically polymerizable compounds, anionically polymerizable compounds, or any combination thereof.

[0019] Examples of the radical polymerizable compound include, but are not limited to, compounds having an unsaturated double bond such as (meth)acrylate compounds, (meth)acrylamide compounds, cyanoacrylate compounds, maleimide compounds, vinyl ether compounds, styrene compounds, and methylene malonates (2-methylene-1,3-dicarbonyl compounds and derivatives thereof), or mixtures of compounds having an unsaturated double bond and thiol compounds (mixtures capable of ene-thiol reaction).

[0020] In this specification, the (meth)acrylate compound refers to a compound having at least one (meth)acryloyl group in the molecule, and includes a monofunctional (meth)acrylate compound having one (meth)acryloyl group and a polyfunctional (meth)acrylate compound having two or more (meth)acryloyl groups. Examples of the monofunctional (meth)acrylate compound 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, ethoxydiethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, butoxydiethylene glycol (meth) Esters of monohydric alcohols and (meth)acrylic acid such as 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, and 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, tetrahydrodicyclopentadienyl (meth)acrylate, 2-(o-phenylphenoxy)ethyl (meth)acrylate, isobol Nylcyclohexyl (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-isopropylcyclohexyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, 1-ethylcyclopentyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, tetrahydropyranyl (meth)acrylate, tetrahydro-2- Examples of the ester include mono(meth)acrylates of polyhydric alcohols or esters of monohydric alcohols and (meth)acrylic acid, such as 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, N-acryloyloxyethylhexahydrophthalimide, α-acryloyl-ω-methoxypoly(oxyethylene), and 1-ethoxyethyl(meth)acrylate.The polyfunctional (meth)acrylate compound is not limited to these. These may be used alone or in combination of two or more. Examples of the polyfunctional (meth)acrylate compound include di(meth)acrylate of tris(2-hydroxyethyl)isocyanurate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, or an oligomer thereof; pentaerythritol tri(meth)acrylate, or an oligomer thereof; poly(meth)acrylate of dipentaerythritol; tris(acryloxyethyl)isocyanurate; caprolactone-modified tris((meth)acryloxyethyl)isocyanurate; poly(meth)acrylate of alkyl-modified dipentaerythritol; poly(meth)acrylate of caprolactone-modified dipentaerythritol; ethoxylated bisphenol A di(meth)acrylate; Examples of the (meth)acrylate include, but are not limited to, dihydrocyclopentadiethyl (meth)acrylate, polyester (meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, ditrimethylolpropane poly(meth)acrylate, polyurethane having two or more (meth)acryloyl groups in one molecule, polyester having two or more (meth)acryloyl groups in one molecule, phenoxyethyl (meth)acrylate, isobornyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, epoxy resin half (meth)acrylate, and (meth)acrylate having an allyloxymethyl group (see JP 2024-009452 A). The (meth)acrylate compound may be any one of the above-mentioned (meth)acrylate compounds, or two or more may be used in combination. Commercially available (meth)acrylate compounds include, for example, polyester acrylate (product name: EBECRYL810) manufactured by Daicel-Allnex Corporation, ditrimethylolpropane tetraacrylate (product name: EBECRYL140) manufactured by Daicel-Allnex Corporation, polyester acrylate (product name: M7100) manufactured by Toagosei Co., Ltd., and dimethylol-tricyclodecane diacrylate (product name: Light Acrylate DCP-A) manufactured by Kyoeisha Chemical Co., Ltd.Examples include, but are not limited to, neopentyl glycol modified trimethylolpropane diacrylate (product name: Kayarad R-604) manufactured by Nippon Kayaku Co., Ltd.

[0021] The (meth)acrylamide compound has an acrylamide group (H ２ C=CHCONH-) or methacrylamide group (H ２ C=C(CH ３ )CONH-) Examples of the (meth)acrylamide compound include, but are not limited to, N,N'-methylenebis(meth)acrylamide, N,N'-ethylenebis(meth)acrylamide, 1,2-di(meth)acrylamide ethylene glycol, and the like.

[0022] The cyanoacrylate compound is H ２Known groups represented by the formula C═C(CN)—COOR can be used. In this formula, R is an ester residue such as an alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, or aryl group. The number of carbon atoms in the ester residue is not particularly limited, but typically, those having 1 to 8 carbon atoms can be used. Ester residues consisting of substituted hydrocarbon groups such as alkoxyalkyl groups and trialkylsilylalkyl groups can also be used. Examples of cyanoacrylate compounds include alkyl and cycloalkyl cyanoacrylates such as methyl cyanoacrylate, ethyl cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, and cyclohexyl cyanoacrylate; alkenyl and cycloalkenyl cyanoacrylates such as allyl cyanoacrylate, methallyl cyanoacrylate, and cyclohexenyl cyanoacrylate; alkynyl cyanoacrylates such as propanegyl cyanoacrylate; aryl cyanoacrylates such as phenyl cyanoacrylate and toluyl cyanoacrylate; methoxyethyl cyanoacrylate, ethoxyethyl cyanoacrylate, and furfuryl cyanoacrylate containing heteroatoms; trimethylsilylmethyl cyanoacrylate, trimethylsilylethyl cyanoacrylate, trimethylsilylpropyl cyanoacrylate, and dimethylvinylsilylmethyl cyanoacrylate containing silicon; but are not limited thereto.These compounds may be used alone or in combination of two or more.

[0023] Maleimide compounds include monofunctional maleimide compounds having one maleimide group and polyfunctional maleimide compounds having two or more maleimide groups, and maleimide compounds having two maleimide groups in particular are sometimes called bismaleimide compounds.

[0024] Examples of bismaleimide compounds include N,N'-(4,4'-diphenylmethane)bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, bis-(3-ethyl-5-methyl-4-maleimidophenyl)methane, m-phenylene bismaleimide (N,N'-1,3-phenylene bismaleimide), 1,6-bismaleimidehexane, 1,2-bismaleimideethane (N,N'-ethyl Examples of the dimaleimide include, but are not limited to, N,N'-(1,2-phenylene)bismaleimide, N,N-1,3-phenylene dimaleimide, N,N'-1,4-phenylene dimaleimide, N,N'-(sulfonyldi-p-phenylene)dimaleimide, N,N'-[3,3'-(1,3-phenylenedioxy)diphenyl]bismaleimide, N,N'-[4,4'-(1,3-phenylenedioxy)diphenyl]bismaleimide, and 4,4'-dimaleimide phenyl ether. These may be used alone or in combination of two or more.

[0025] When a low room temperature modulus is required for the cured resin composition, a bismaleimide having a hydrocarbon group derived from a dimer acid can be used as the bismaleimide compound. Such bismaleimides are described, for example, in JP 2015-193725 A. Commercially available bismaleimides having a hydrocarbon group derived from a dimer acid include, but are not limited to, products under the trade names "BMI-689," "BMI-1500," and "BMI-1700," which are liquid at 25°C, and "BMI-3000," which is solid at 25°C (all manufactured by Designer Molecules Inc.). These compounds may be used alone or in combination of two or more.

[0026] Examples of monofunctional maleimide compounds include, but are not limited to, monofunctional aliphatic maleimide compounds such as N-n-butylmaleimide, N-hexylmaleimide, 2-maleimidoethyl-ethyl carbonate, 2-maleimidoethyl-propyl carbonate, and N-ethyl-(2-maleimidoethyl)carbamate; alicyclic monofunctional maleimide compounds such as N-cyclohexylmaleimide; N-arylmaleimides such as N-phenylmaleimide; and N-aralkylmaleimides such as N-benzylmaleimide. The aliphatic maleimides and alicyclic maleimides may have a substituent, and examples of the substituent include a phenyl group, a benzyl group, and a hydroxy group. The N-arylmaleimides and N-aralkylmaleimides may have a substituent, and examples of the substituent include, but are not limited to, an alkyl group, a nitro group, a hydroxy group, an alkoxy group, a carboxyl group, and a halogeno group. Commercially available monofunctional maleimides include, for example, Imilex （Ｒ） -C, Imilex （Ｒ） -P (both manufactured by Nippon Shokubai Co., Ltd.) and O-CPMI (manufactured by Daiwa Kasei Kogyo Co., Ltd.), but are not limited to these. These may be used alone or in combination of two or more.

[0027] The vinyl ether compound has a vinyl ether group (H ２ C═CH—O—). Examples of vinyl ether compounds include, but are not limited to, ethyl vinyl ether, triethylene glycol divinyl ether, trimethylolpropane trivinyl ether, hydroxybutyl vinyl ether, dodecyl vinyl ether, cyclohexyl vinyl ether, 1,4-butanediol divinyl ether, nonanediol divinyl ether, cyclohexanediol divinyl ether, and cyclohexanedimethanol divinyl ether. These compounds may be used alone or in combination of two or more.

[0028] Styrene compounds contain a styrene group (H ２ C=CH-C ６ H ５-). Examples of the styrene compound include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-t-butylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, N,N-diethyl-4-aminoethylstyrene, and 4-methoxystyrene, but are not limited to these. These may be used alone or in combination of two or more.

[0029] Methylene malonates are malonates having at least one methylene group in the molecule, including monofunctional methylene malonates having one methylene group and polyfunctional methylene malonates having two or more methylene groups. The methylene malonates preferably have a molecular weight of 220 or more. There are no particular limitations on the type of methylene malonate that can be used, and various disclosed methylene malonates can be used, including compounds described in WO 2018 / 212330 A1 and the like. Methylene malonates may be used alone or in combination of two or more.

[0030] The thiol compound in the mixture of a compound having an unsaturated double bond and a thiol compound is a compound containing at least one thiol group, and the thiol group can undergo a radical addition reaction (ene-thiol reaction) with the unsaturated double bond of the compound having an unsaturated double bond. Examples of thiol compounds include monofunctional thiol compounds having one thiol group and polyfunctional thiol compounds having two or more thiol groups. In one embodiment, the thiol compound contains at least a polyfunctional thiol compound. In one embodiment, the thiol compound contains a combination of a bifunctional thiol compound and a trifunctional or higher functional thiol compound. In one embodiment, the thiol compound contains a combination of a monofunctional thiol compound and a polyfunctional thiol compound. Thiol compounds can also be divided into thiol compounds having a hydrolyzable partial structure such as an ester bond in the molecule (i.e., hydrolyzable) and thiol compounds not having such a partial structure (i.e., non-hydrolyzable). Examples of hydrolyzable 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.: EGMP- 4), dipentaerythritol hexakis(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: DPMP), pentaerythritol tetrakis(3-mercaptobutyrate) (manufactured by Resonac Co., Ltd.: Karenz MT (registered trademark) PE1), 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (manufactured by Resonac Co., Ltd.: Karenz MT (registered trademark) NR1), and the like can be mentioned, but are not limited to these. These may be used alone or in combination of two or more. 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 (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, 1,3,4,6-tetrakis(2-mercaptoethyl)-3a,6a-di Methyl glycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl)-3a,6a-dimethyl glycoluril, 1,3,4,6-tetrakis(mercaptomethyl)-3a,6a-diphenyl glycoluril, 1,3,4,6-tetrakis(2-mercaptoethyl)-3a,6a-diphenyl glycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl)-3a,6a-diphenyl glycoluril, tris(3-mercaptopropyl) isocyanurate, 1,3,5-tris[3-(2-mercaptopropyl)methyl]-3a,6a-diphenyl glycoluril, 1,3,5-tris[2-(3-mercaptoethylsulfanyl)propyl]isocyanurate, 1,3,5-tris[2-(3-mercaptopropoxy)ethyl]isocyanurate, pentaerythritol trippropanethiol (manufactured by SC Organic Chemical Co., Ltd.: PEPT), 3-[2,3-bis(3-sulfanylpropoxy)propoxy]propane-1-thiol, 1,2,3-tris(3-mercaptopropoxy)propane, 3-[2,2-bis[(3-mercaptopropoxy)methyl]butoxy]-1-propanethiol, pentaerythritol tetrapropane thiol, 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)-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(mercapto 3,4,8,9-tetrakis(mercaptomethylthio)-1,11-dimercapto-2,5,7,10-tetrathiaundecane, 3,4,8,9,13,14-hexakis(mercaptomethylthio)-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) methylthio)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-dithietanyl)]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 bis(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-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-1,3-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, 2,2'-[cyclohexylidenebis(thio-2,1-ethanediylthio)]bis[ethanethiol], 4,4'-[(1,3-phenylene)bis(oxy)]bis[1-butanethiol], and the various bifunctional thiol compounds disclosed in WO 2019 / 082962, as well as dimers, trimers, and tetramers of the above thiol compounds, can be mentioned, but are not limited to these. These may be used alone or in combination of two or more.

[0031] The cationically polymerizable compound is a compound having one or more cationically polymerizable groups in the molecule. Examples of the cationically polymerizable compound include, but are not limited to, compounds having an epoxy group, compounds having an oxetanyl group, compounds having a vinyl ether group, compounds having other cationically polymerizable groups, and compounds having any combination of these cationically polymerizable groups.

[0032] In this specification, a compound having an epoxy group refers to a compound having at least one epoxy group in the molecule, and is also referred to as an epoxy compound. Examples include monofunctional epoxy compounds having one epoxy group and polyfunctional epoxy compounds having two or more epoxy groups. In one embodiment, the epoxy compound preferably contains at least a polyfunctional epoxy compound, and may contain a combination of a polyfunctional epoxy compound and a monofunctional epoxy compound. Epoxy compounds can be broadly classified into epoxy compounds having an aromatic ring skeleton, aliphatic epoxy compounds, and alicyclic epoxy compounds depending on the type of skeleton.

[0033] In this specification, a compound having an oxetanyl group is a compound having at least one oxetane ring (e.g., a 3-oxetanyl group) in the molecule, and is also referred to as an oxetane compound. In one embodiment, the oxetane compound preferably has 1 to 6 oxetanyl groups in the molecule, and more preferably has 1 to 2 oxetanyl groups in the molecule.

[0034] In this specification, a compound having a vinyl ether group is a compound having at least one vinyl ether group in the molecule.

[0035] Specific examples of the cationic polymerizable compound include glycidyl ethers of tetra(hydrophenyl)alkanes, glycidyl ethers of tetrahydroxybenzophenone, epoxidized polyvinylphenol, p-tert-butylphenyl glycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, 1,2-epoxytetradecane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexanecarboxylate, 6-methyl-3,4-eth ... 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexanecarboxylate, methylenebis(3,4-epoxycyclohexane), propanediol Pan-2,2-diyl-bis(3,4-epoxycyclohexane), 2,2-bis(3,4-epoxycyclohexyl)propane, dicyclopentadiene diepoxide, ethylene bis(3,4-epoxycyclohexanecarboxylate), limonene dioxide (1,2:8,9-diepoxylimonene), (3,3',4,4'-diepoxy)bicyclohexyl, dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, 1-epoxyethyl-3,4-epoxycyclohexane, 1,2-epoxy-2-epoxyethylcyclohexane, 1,2-epoxy-4-vinylcyclohexane, α-pinene oxide, 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, epoxidized polybutadiene, styrene-butadiene copolymer compounds in which some or all of the double bonds have been epoxidized, polyalkylene oxide-modified bisphenol A type epoxy, lauryl alcohol polyethylene glycol glycidyl ether, diglycidyl ether of alicyclic diol, diglycidyl ether of alicyclic diol Diglycidyl ether of polyalkylene oxide adduct, bis[1-ethyl(3-oxetanyl)]methyl ether (also known as (3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane)), xylylene bisoxetane, 4,4'-bis[3-ethyl-(3-oxetanyl)methoxymethyl]biphenyl, 1,4-bis(3-ethyl-3-oxetanylmethoxy)methylbenzene, (bis[(3-ethyl-3-oxetanyl)methyl]isophthalate), 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyl Xyloxetane, (3-ethyloxetan-3-yl)methyl methacrylate, 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane, 3-ethyl-3-(4-hydroxybutyl)oxymethyloxetane, 3-ethyl-3-phenoxymethyloxetane, oxetanyl silsesquioxetane, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, phenol novolac oxetane, 1,4-butanediol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, normal propyl vinyl ether, isopropyl vinyl ether, normal butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, 2-(2-vinyloxyethoxy)ethyl acrylate, 2-(2-vinyloxyethoxy)ethyl methacrylate, 1,4-cyclohexanedimethanol monovinyl ether, 1,Examples include, but are not limited to, 4-cyclohexanedimethanol divinyl ether.

[0036] Commercially available cationically polymerizable compounds include EPICLON (registered trademark) 850, 850-S, EXA-850CRP, and EXA-8067 manufactured by DIC Corporation; AER9000 manufactured by Asahi Kasei Corporation; EP-4000S, EP-4003S, EP-4005, EP-4010S, EP-4088S, and EP-4088L manufactured by ADEKA Corporation; Rikaresin BEO-60E manufactured by New Japan Chemical Co., Ltd.; EX-171 manufactured by Nagase ChemteX Corporation; EPICLON (registered trademark) 830-S, EXA-830LVP, and E manufactured by DIC Corporation. XA-835LV; EPICLON (registered trademark) HP-4032D, HP-720H manufactured by DIC Corporation; EPICLON (registered trademark) N-740, N-770 manufactured by DIC Corporation; EPICLON (registered trademark) N-660, N-670, N-655-EXP-S manufactured by DIC Corporation; ADEKA GLYCIROL (registered trademark) ED-509E, ED-509S manufactured by ADEKA Corporation; OPP-G manufactured by Sanko Co., Ltd.; Epolite 100MF manufactured by Kyoeisha Chemical Co., Ltd.; AER-9000 manufactured by Asahi Kasei Corporation; jER manufactured by Mitsubishi Chemical Corporation YX7400N; jER YX8000 manufactured by Mitsubishi Chemical Corporation; CELLOXIDE (registered trademark) 2021P manufactured by Daicel Corporation; CELLOXIDE (registered trademark) 8010 manufactured by Daicel Corporation; EHPE3150 manufactured by Daicel Corporation; EPOLEAD PB manufactured by Daicel Corporation; EPOFRIEND manufactured by Daicel Corporation; HiREM-1 and HiREM-2 manufactured by Shikoku Chemicals Corporation; OXT-191 manufactured by Toagosei Co., Ltd.; OXT-221 manufactured by Toagosei Co., Ltd.; PHOX manufactured by Toagosei Co., Ltd., and the like, but are not limited to these.

[0037] The cationically polymerizable compounds may be used alone or in combination of two or more.

[0038] Examples of anionically polymerizable compounds include the epoxy group-containing compounds listed above as examples of cationic polymerizable compounds, as well as their curing agents, such as thiol-based curing agents, phenol-based curing agents, acid anhydride-based curing agents, and amine-based curing agents. Methylene malonates listed above as examples of radically polymerizable compounds also qualify as anionically polymerizable compounds. Furthermore, the (meth)acrylate compounds listed above as examples of radically polymerizable compounds also qualify as anionically polymerizable compounds when used in combination with a thiol compound. These compounds may be used alone or in combination of two or more. The thiol compounds listed above can be used as thiol-based curing agents. Examples of phenolic curing agents include monomers, oligomers, and polymers containing phenolic hydroxyl groups, including, but not limited to, phenol novolac resins, alkylated or allylated products thereof, cresol novolac resins, phenol aralkyl (including phenylene and biphenylene skeleton) resins, naphthol aralkyl resins, triphenolmethane resins, and dicyclopentadiene-type phenolic resins. Examples of acid anhydride curing agents include, but are not limited to, alkylated tetrahydrophthalic anhydrides such as methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhimic anhydride, alkenyl-substituted succinic anhydride, methylnadic anhydride, and glutaric anhydride.Examples of the amine-based curing agent include, but are not limited to, aliphatic polyamines such as triethylenetetraamine, tetraethylenepentamine, m-xylenediamine, trimethylhexamethylenediamine, and 2-methylpentamethylenediamine; alicyclic polyamines such as isophoronediamine, 1,3-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane; piperazine-type polyamines such as N-aminoethylpiperazine and 1,4-bis(2-amino-2-methylpropyl)piperazine; and aromatic polyamines such as diethyltoluenediamine, dimethylthiotoluenediamine, 4,4'-diamino-3,3'-diethyldiphenylmethane, bis(methylthio)toluenediamine, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis(4-aminobenzoate), and polytetramethyleneoxide-di-p-aminobenzoate. Commercially available products include Epicure-W and Epicure-Z (Yuka Shell Epoxy Co., Ltd., trade names), jER Cure (registered trademark)-W and jER Cure (registered trademark)-Z (Mitsubishi Chemical Corporation, trade names), Kayahard A-A, Kayahard A-B, and Kayahard A-S (Nippon Kayaku Co., Ltd., trade names), Thothamine HM-205 (Nippon Steel Sumikin Chemical Co., Ltd., trade names), Adeka Hardener EH-101 (ADEKA Corporation, trade names), Epomic Q-640 and Epomic Q-643 (Mitsui Chemicals, Inc., trade names), DETDA80 (Lonza, trade names), and Thothamine HM-205 (Nippon Steel Sumikin Chemical Co., Ltd., trade names), but are not limited to these.

[0039] The polymerizable compound may be any one of a radically polymerizable compound, a cationically polymerizable compound, and an anionically polymerizable compound, or any combination thereof.

[0040] The content of the polymerizable compound in the photocurable resin composition may be 0.1 to 99 parts by mass per 100 parts by mass of the total amount of the photocurable resin composition. In the curing method of this embodiment, even if a large amount of a shielding material such as a filler is present in the photocurable resin composition, the photocurable resin composition can achieve both surface curability and deep curability. In some embodiments, the content of the polymerizable compound in the photocurable resin composition is preferably 1 to 50 parts by mass, more preferably 5 to 30 parts by mass, per 100 parts by mass of the total amount of the photocurable resin composition. In another embodiment, the content of the polymerizable compound in the photocurable resin composition is preferably 30 to 99 parts by mass, more preferably 50 to 99 parts by mass, and even more preferably 60 to 99 parts by mass, per 100 parts by mass of the total amount of the photocurable resin composition. The content of the polymerizable compound in the photocurable resin composition is preferably 30 to 99.5 parts by mass, more preferably 40 to 99 parts by mass, and even more preferably 50 to 98 parts by mass, relative to 100 parts by mass of the total amount of all organic substances contained in the photocurable resin composition (excluding low-stress-imparting materials such as organic fillers and elastomers).

[0041] The curing method of this embodiment is applicable to an adhesion method, sealing method, or coating method for fixing, joining, or protecting semiconductor devices or electronic components, or components constituting these. This adhesion method, sealing method, or coating method enables good fixing, joining, or protection for general-purpose plastics (e.g., PE, PS, PP, etc.), engineering plastics (e.g., LCP (liquid crystal polymer), polyamide, polycarbonate, etc.), ceramics, and metals (e.g., copper, nickel, etc.), and is applicable to fixing, joining, or protecting semiconductor devices or electronic components, or components constituting these. Examples of semiconductor devices or electronic components include, but are not limited to, HDDs, semiconductor elements, optical sensor modules such as image sensor modules and time-of-flight sensor modules, other semiconductor modules, and integrated circuits.

[0042] [Bonding Method] Another aspect of the present invention is a method for bonding at least two components using a photocurable resin composition, the method comprising the steps of: applying a photocurable resin composition containing a polymerizable compound to at least one of the at least two components; attaching the other component to the component coated with the photocurable resin composition via the photocurable resin composition, or attaching the component coated with the photocurable resin composition to the other component via the photocurable resin composition; and irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm simultaneously or sequentially under atmospheric conditions to polymerize the polymerizable compound using at least a photon upconversion mechanism. The bonding method of this aspect encompasses the method for curing a photocurable resin composition of the above aspect. The bonding method of this aspect achieves both surface curing and deep curing of the photocurable resin composition, thereby imparting excellent adhesive strength.

[0043] In the first step, a photocurable resin composition containing a polymerizable compound is applied to at least one of at least two components. The photocurable resin composition containing a polymerizable compound is the same as the photocurable resin composition containing a polymerizable compound in the curing method of the above embodiment. The component is preferably a component constituting a semiconductor device or electronic component, such as, but not limited to, a semiconductor element or a substrate. The component material may be any of general-purpose plastics (e.g., PE, PS, PP, etc.), engineering plastics (e.g., LCP (liquid crystal polymer), polyamide, polycarbonate, etc.), ceramics, or metals (e.g., copper, nickel). The method for applying the resin composition is not particularly limited, and the resin composition can be applied to the desired portion of a component, such as a substrate, by a known printing method, dispensing method, or coating method. Printing methods include, but are not limited to, inkjet printing, screen printing, lithographic printing, carton printing, metal printing, offset printing, gravure printing, flexographic printing, etc. Dispensing methods include, but are not limited to, methods using a jet dispenser, an air dispenser, etc. Examples of coating methods include, but are not limited to, dip coating, spray coating, bar coater coating, gravure coating, reverse gravure coating, and spin coater coating.

[0044] Next, another part is attached to the part coated with the photocurable resin composition via the photocurable resin composition, or the part coated with the photocurable resin composition is attached to the other part via the photocurable resin composition. Any known method may be used for the attachment. If necessary, after attachment, the parts may be pressed together while applying a load.

[0045] Next, under atmospheric conditions, the photocurable resin composition is irradiated simultaneously or sequentially with light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm, and the polymerizable compound is polymerized using at least a photon upconversion mechanism. This process corresponds to the method for curing a photocurable resin composition of the above embodiment, and the detailed conditions of this process are the same as those of the method for curing a photocurable resin composition of the above embodiment. Once the surface of the photocurable resin composition is cured by irradiation with light having a wavelength of 500 nm or less, light having a wavelength exceeding 500 nm, which is irradiated simultaneously or subsequently, penetrates the interior (deep portion) of the resin composition and undergoes wavelength conversion by the photon upconversion mechanism without oxygen inhibition, causing polymerization of the polymerizable compound in the interior (deep portion) of the resin composition to cure the interior (deep portion) of the resin composition. Alternatively, the interior (deep portion) of the resin composition is cured by first irradiating it with light having a wavelength exceeding 500 nm, and then the surface of the photocurable resin composition is cured by irradiating it with light having a wavelength of 500 nm or less.

[0046] [Sealing Method] Another aspect of the present invention is a method for sealing gaps between or within components with a curable resin composition, the method comprising the steps of: applying or injecting a photocurable resin composition containing a polymerizable compound into the gap between or within the components; and irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm simultaneously or sequentially under atmospheric conditions to polymerize the polymerizable compound using at least a photon upconversion mechanism. The sealing method of this aspect encompasses the method for curing a photocurable resin composition of the above aspect. The sealing method of this aspect achieves both surface curability and deep curability of the photocurable resin composition, enabling highly reliable sealing.

[0047] The photocurable resin composition containing a polymerizable compound is the same as the photocurable resin composition containing a polymerizable compound in the curing method of the above embodiment. The components are the same as those in the bonding method. Examples of application or injection methods include, but are not limited to, the application method in the bonding method and a potting method. The step of simultaneously or sequentially irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength greater than 500 nm under atmospheric conditions and polymerizing the polymerizable compound using at least a photon upconversion mechanism corresponds to the curing method of the photocurable resin composition of the above embodiment, and the detailed conditions of this step are the same as those of the curing method of the photocurable resin composition of the above embodiment. Once the surface of the photocurable resin composition is cured by irradiation with light having a wavelength of 500 nm or less, the simultaneously or subsequently irradiated light having a wavelength greater than 500 nm penetrates the interior (deep portion) of the resin composition and undergoes wavelength conversion by the photon upconversion mechanism without oxygen inhibition, causing polymerization of the polymerizable compound to proceed within the interior (deep portion) of the resin composition, thereby hardening the interior (deep portion) of the resin composition. Alternatively, the interior (deep portion) of the resin composition can be cured by first irradiating it with light having a wavelength exceeding 500 nm, and then the surface of the photocurable resin composition can be cured by irradiating it with light having a wavelength of 500 nm or less. Because a large curing depth can be obtained, the resin composition present deep in gaps that are difficult for ultraviolet light to reach can be cured, thereby achieving suitable sealing.

[0048] [Coating Method] Another aspect of the present invention is a method for coating the surface of an object with a photocurable resin composition, the method comprising the steps of: applying a photocurable resin composition containing a polymerizable compound to the object; and irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm simultaneously or sequentially under atmospheric conditions to polymerize the polymerizable compound using at least a photon upconversion mechanism. The coating method of this aspect encompasses the method for curing a photocurable resin composition of the above aspect. The coating method of this aspect achieves both surface curability and deep curability of the photocurable resin composition, allowing for highly reliable coating.

[0049] The photocurable resin composition containing a polymerizable compound is the same as the photocurable resin composition containing a polymerizable compound in the curing method of the above embodiment. The target object may be a semiconductor device or electronic component, or a component constituting the same. Examples of semiconductor devices or electronic components include, but are not limited to, HDDs, semiconductor elements, optical sensor modules such as image sensor modules and TOF sensor modules, other semiconductor modules, and integrated circuits. Examples of components constituting the semiconductor device or electronic component include, but are not limited to, semiconductor elements and substrates. The material of the component may be any of general-purpose plastics (e.g., PE, PS, PP, etc.), engineering plastics (e.g., LCP (liquid crystal polymer), polyamide, polycarbonate, etc.), ceramics, or metals (e.g., copper, nickel), etc. The application method is the same as that in the above-mentioned adhesion method. The step of simultaneously or sequentially irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength exceeding 500 nm under atmospheric conditions to polymerize the polymerizable compound using at least a photon upconversion mechanism corresponds to the method for curing a photocurable resin composition of the above embodiment, and the detailed conditions of this step are the same as those of the method for curing a photocurable resin composition of the above embodiment. Once the surface of the photocurable resin composition is cured by irradiation with light having a wavelength of 500 nm or less, light having a wavelength exceeding 500 nm, which is irradiated simultaneously or subsequently, penetrates the interior (deep portion) of the resin composition and undergoes wavelength conversion by the photon upconversion mechanism without oxygen inhibition, causing polymerization of the polymerizable compound in the interior (deep portion) of the resin composition to cure the interior (deep portion) of the resin composition. Alternatively, the interior (deep portion) of the resin composition is cured by first irradiating with light having a wavelength exceeding 500 nm, and then the surface of the photocurable resin composition is cured by irradiating with light having a wavelength of 500 nm or less.

[0050] [Photon Up-Conversion Material] The photo-curable resin composition used in the photo-curable resin composition curing method, bonding method, sealing method, and coating method of the above-described embodiments preferably contains a polymerizable compound and further contains a photon up-conversion material. When irradiated with specific light, the photon up-conversion material generates a high-energy state through multiphoton excitation, triplet-triplet annihilation, or the like, and emits light with a shorter wavelength than the incident light during the relaxation process. By incorporating this photon up-conversion material into a resin composition and irradiating the resin composition with long-wavelength light, the photon up-conversion material performs wavelength conversion within the resin composition. This allows the photon up-conversion material to generate light with a wavelength of 500 nm or less, activating the polymerizable compound and curing the resin composition. The emission wavelength of the photon up-conversion material preferably includes wavelengths of 500 nm or less, more preferably wavelengths of 450 nm or less, even more preferably wavelengths of 430 nm or less, and particularly preferably wavelengths of 400 nm or less. In one embodiment, the emission wavelength of the photon upconversion material includes the wavelength of ultraviolet light (200 nm to 380 nm). Although photon upconversion materials based on any photon upconversion mechanism can be used, the photon upconversion material is preferably a triplet-triplet annihilation type photon upconversion material, a multi-photon excitation type photon upconversion material, or a combination thereof.

[0051] Triplet-triplet annihilation type photon upconversion material: In one embodiment, the photon upconversion material is a triplet-triplet annihilation type photon upconversion material. Triplet-triplet annihilation type photon upconversion material uses a combination of a donor and an acceptor. As triplet-triplet annihilation type photon upconversion materials, for example, those described in JP 2021-080335 A and JP 2020-056030 A can be used.

[0052] <Acceptor> The acceptor (acceptor compound) is not particularly limited as long as it is a compound (light emitter) that undergoes triplet energy transfer from a donor, becomes an excited singlet state through triplet-triplet annihilation, and is capable of generating photon upconversion luminescence. Examples of acceptors include, but are not limited to, compounds having a naphthalene structure, an anthracene structure, a tetracene structure, a pyrene structure, a perylene structure, a biphenyl structure, a terphenyl structure, a perylene diimide structure, a naphthalene diimide structure, or a BODIPY (boron dipyrromethene; 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) structure. Specific examples of acceptors include, but are not limited to, 9,10-diphenylanthracene (DPA), tetra-tert-butylperylene, anthracene (An), 2,5-diphenyloxazole (PPO), rubrene, 2-chloro-bis-phenylethynylanthracene (2CBPEA), 9,10-bis(phenylethynyl)anthracene (BPEA), 9,10-bis(phenylethynyl)naphthacene (BPEN), perylene, coumarin 343 (C343), 9,10-dimethylanthracene (DMA), pyrene, tert-butylpyrene, and boron dipyrromethene (BODIPY) derivatives BD-1 and BD-2 having an iodophenyl group, and halogenated derivatives of these compounds. Other specific examples of the acceptor include the acceptors described in JP-A-2021-080335 and JP-A-2020-056030.

[0053] <Donor> The donor (donor compound) is not particularly limited as long as it absorbs incident light, undergoes intersystem crossing from an excited singlet state to an excited triplet state, and causes triplet-triplet energy transfer to an acceptor. Examples of donors include, but are not limited to, metal atoms such as Pt, Pd, Zn, Ru, Re, Ir, Os, Cu, Ni, Co, Cd, Au, Ag, Sn, Sb, Pb, P, and As, and compounds containing organic moieties such as a porphyrin structure, a phthalocyanine structure, a fullerene structure, and a 2-phenylpyridinato structure. Specific examples of donors include palladium octabutoxyphthalocyanine (PdOBuPc), platinum tetraphenyltetranaphthoporphyrin (PtTPTNP), palladium(II)-meso-tetraphenyl-tetrabenzoporphyrin (PdTPTBP), [Ru(dmb) ３ ] ２＋ (dmb is 4,4'-dimethyl-2,2'-bipyridine), palladium(II) tertraanthraporphyrin (PdTAP), platinum(II) tetraphenyltetrabenzoporphyrin (PtTPBP), palladium meso-tetraphenyltetrabenzoporphyrin (PdPh4TBP), palladium octaethylporphyrin (PdOEP), 11,15,18,22,25 octabutoxyphthalocyanine (PdPc(OBu) ８ ), octaethylporphyrin (OEP), platinum octaethylporphyrin (PtOEP), zinc(II) octaethylporphyrin (ZnOEP), zinc(II) meso-tetraphenylporphine (ZnTPP), palladium(II) tetraphenyltetrabenzoporphyrin (PdTPBP), palladium(II) meso-tetraphenyl-octamethoxide tetranaphtholporphyrin (PdPh ４ OMe ８ TNP), 2-methoxythioxanthone (2MeOTX), and Ir(ppy) ３ (ppy = 2-phenylpyridine) are included, but are not limited to these. Other specific examples of the donor include donors described in JP-A-2021-080335 and JP-A-2020-056030.

[0054] By appropriately selecting the combination of donor and acceptor, the wavelengths of incident light and emitted light can be controlled. The combination of donor and acceptor may be one pair, or two or more pairs. For example, in certain embodiments, selecting multiple combinations of donor and acceptor enables energy transfer from one photon upconversion material to another photon upconversion material in the resin composition. This stepwise energy transfer allows the emission wavelength of the photon upconversion material to be adjusted from the desired incident light to ultimately include wavelengths of 500 nm or less, thereby allowing the resin composition to be photocured using the desired incident light. The molar ratio of donor to acceptor can be, for example, donor:acceptor = 1:1 to 1:100,000. By appropriately selecting the combination and molar ratio of donor and acceptor, the emission wavelength of a triplet-triplet annihilation type photon upconversion material that emits light upon irradiation with light having a wavelength exceeding 500 nm can be adjusted to include wavelengths of 500 nm or less.

[0055] The wavelength range of excitation light that causes upconversion emission from such triplet-triplet annihilation type photon upconversion materials is preferably a wavelength greater than 500 nm, for example, a wavelength in the range of greater than 500 nm and less than or equal to 2000 nm. The wavelength of upconversion emission from triplet-triplet annihilation type photon upconversion materials preferably includes wavelengths of 500 nm or less, more preferably wavelengths of 450 nm or less, even more preferably wavelengths of 430 nm or less, and particularly preferably wavelengths of 400 nm or less. In an embodiment, the emission wavelength of the triplet-triplet annihilation type photon upconversion material includes the wavelength of ultraviolet light (200 nm to 380 nm).

[0056] Any one of the donors may be used alone or in combination of two or more thereof. Any one of the acceptors may be used alone or in combination of two or more thereof.

[0057] From the viewpoint of the curability of the photocurable resin composition, the content of the triplet-triplet annihilation type photon upconversion material in the photocurable resin composition is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 10 parts by mass, and even more preferably 0.01 to 10 parts by mass, relative to 100 parts by mass of the total amount of the photocurable resin composition. In an embodiment, the amount of the triplet-triplet annihilation type photon upconversion material is preferably 0.001 mmol / L to 1 mmol / L, more preferably 0.001 mmol / L to 0.9 mmol / L, even more preferably 0.001 mmol / L to 0.8 mmol / L, particularly preferably 0.001 mmol / L to 0.7 mmol / L, and most preferably 0.001 mmol / L to 0.5 mmol / L.

[0058] The content of the donor in the photocurable resin composition is preferably 0.0001 to 10 parts by mass, more preferably 0.005 to 5 parts by mass, relative to 100 parts by mass of the total amount of the photocurable resin composition. The content of the acceptor in the photocurable resin composition is preferably 0.001 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the total amount of the photocurable resin composition.

[0059] Multiphoton Excitation Type Photon Up-Conversion Material In certain embodiments, the photon up-conversion material is a multiphoton excitation type photon up-conversion material. A multiphoton excitation type photon up-conversion material is a material that emits up-conversion light by multiphoton excitation. The wavelength of the up-conversion light emitted by the multiphoton excitation type photon up-conversion material preferably includes wavelengths of 500 nm or less, more preferably wavelengths of 450 nm or less, even more preferably wavelengths of 430 nm or less, and particularly preferably wavelengths of 400 nm or less. In certain embodiments, the emission wavelength of the multiphoton excitation type photon up-conversion material includes ultraviolet light wavelengths (200 nm to 380 nm). The multiphoton excitation type photon up-conversion material may have an emission peak in the red or green region in addition to the UV-A, violet, or blue region. In this specification, the red region refers to the wavelength region of 600 to 800 nm, the green region refers to the wavelength region of 500 to 600 nm, and the blue region refers to the wavelength region of 400 to 500 nm. In one embodiment, the multi-photon excitation type photon up-conversion material preferably has an emission intensity in the wavelength region of 500 nm or less.

[0060] In multi-photon excitation type photon up-conversion materials, an optically inactive host material is doped with a rare earth element, thereby exhibiting up-conversion luminescence characteristics. In multi-photon excitation type photon up-conversion materials, up-conversion luminescence of any wavelength can be obtained by appropriately selecting the type and amount of rare earth element contained (doping amount).

[0061] The rare earth element is not particularly limited as long as it is a rare earth element capable of upconversion emission, but typically includes rare earth elements that become trivalent ions. Among them, it is preferable to use a combination of at least two or more rare earth elements selected from the group consisting of erbium (Er), holmium (Ho), praseodymium (Pr), thulium (Tm), neodymium (Nd), gadolinium (Gd), europium (Eu), ytterbium (Yb), samarium (Sm), and cerium (Ce). In addition, examples of the combination of rare earth elements include a combination of ytterbium (Yb), erbium (Er) and thulium (Tm), a combination of praseodymium (Pr), erbium (Er) and thulium (Tm), and a combination of erbium (Er) and thulium (Tm), among which, a combination of ytterbium (Yb), erbium (Er) and thulium (Tm), and a combination of ytterbium (Yb) and thulium (Tm) are preferred. In particular, examples of the combination of rare earth elements having a strong upconversion emission at blue light wavelengths include Yb ３＋ / Tm ３＋ Examples include:

[0062] The wavelength range of the excitation light that causes such a multi-photon excitation type photon upconversion material to emit upconversion light is preferably a wavelength of more than 500 nm, for example, a wavelength in the range of more than 500 nm and not more than 2000 nm.

[0063] The host material (host material) is not particularly limited as long as it supports a rare earth element and supports the rare earth element in a state capable of upconversion emission, and may be an organic substance that reacts with the rare earth element to form a complex, dendrimer, etc., or an inorganic substance. Inorganic substances are preferred because it is easy to incorporate the rare earth element in a state capable of emitting light.

[0064] As such an inorganic base material, a material that is transparent to the excitation light is preferred from the viewpoint of luminous efficiency, and specifically, among them, halides such as fluorides and chlorides, oxides, sulfides, oxysulfides, etc. are preferably used. Examples of halides include barium chloride (BaCl２ ), lead chloride (PbCl ２ ), lead fluoride (PbF ２ ), cadmium fluoride (CdF ２ ), lanthanum fluoride (LaF ３ ), yttrium fluoride (YF ３ Examples of oxides include, but are not limited to, yttrium oxide (Y ２ O ３ ), cerium oxide (CeO ２ ), aluminum oxide (Al ２ O ３ ), silicon dioxide (SiO ２ ), tantalum oxide (Ta ２ O ５ ) and the like, but are not limited to these. A coating material may be formed around the multiphoton excitation type photon up-conversion material that uses a halide as a base material. The above-mentioned oxides can be used as this coating material.

[0065] Also, the core (NaYREF ４ ) / Shell (NaYF ４ ) (RE=rare earth element) can also be used.

[0066] The multiphoton excitation type photon up-conversion material can be produced by a known method, for example, a gas evaporation method including a high-frequency plasma method, a sputtering method, a glass crystallization method, a chemical deposition method, a reverse micelle method, a sol-gel method and similar methods, a precipitation method including a hydrothermal synthesis method and a coprecipitation method, a spray method, etc. For the production method of the multiphoton excitation type photon up-conversion material, reference can be made to the method described in JP 2006-117864 A, for example.

[0067] Commercially available multi-photon excitation photon upconversion materials may be used, for example, core-shell upconversion phosphor nanoparticles with an excitation wavelength of 975 nm and an emission wavelength of 365 nm are commercially available from Hefei Fluonano Biotech Co., Ltd. under the product code 201-30-365.

[0068] The multiphoton excitation type photon upconversion materials may be used alone or in combination of two or more. For example, in one embodiment, the use of two or more multiphoton excitation type photon upconversion materials in combination enables energy transfer from one photon upconversion material to another photon upconversion material in the resin composition. Such stepwise energy transfer allows the emission wavelength of the photon upconversion material to be adjusted from the desired incident light so that it ultimately includes a wavelength of 500 nm or less, thereby allowing the resin composition to be photocured using the desired incident light.

[0069] The content of the multiphoton excitation type photon up-conversion material in the photocurable resin composition is preferably 0.1 to 60 parts by mass, and more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the total amount of the photocurable resin composition, from the viewpoints of photoconversion efficiency and photocuring degree.

[0070] Either a triplet-triplet annihilation type photon upconversion material or a multiphoton excitation type upconversion material may be used alone, or any combination thereof may be used. For example, in certain embodiments, by using a triplet-triplet annihilation type photon upconversion material in combination with a multiphoton excitation type upconversion material, energy transfer from the triplet-triplet annihilation type photon upconversion material to the multiphoton excitation type upconversion material, or from the multiphoton excitation type upconversion material to the triplet-triplet annihilation type photon upconversion material, is possible in the resin composition. Such stepwise energy transfer allows the emission wavelength of the photon upconversion material from the desired incident light to be adjusted to ultimately include wavelengths of 500 nm or less, thereby allowing the resin composition to be photocured using the desired incident light.

[0071] The photocurable resin composition used in the photocurable resin composition curing method, bonding method, sealing method, and coating method of the above aspects preferably satisfies at least one of the following characteristics (a) and (b): (a) the polymerizable compound includes a maleimide compound; (b) the photocurable resin composition further includes a photopolymerization initiator. The maleimide compound and the photopolymerization initiator are activated by light having a wavelength of 500 nm or less generated by a photon upconversion mechanism to generate active species such as radicals, cations, and anions, thereby promoting polymerization of the polymerizable compound.

[0072] In the characteristic (a), the maleimide compound is activated by light having a wavelength of 500 nm or less, which is first or simultaneously irradiated onto the photocurable resin composition, and light having a wavelength of more than 500 nm, which is simultaneously or subsequently irradiated, to generate radicals and promote polymerization of the radical polymerizable compound. That is, the maleimide compound functions not only as a polymerizable compound but also as a photoradical polymerization initiator, promoting polymerization of the radical polymerizable compound containing the maleimide compound itself without the need for a separate photoradical polymerization initiator. From the viewpoint of workability under fluorescent lamps, the maleimide compound preferably has an absorption wavelength of less than 500 nm, more preferably an absorption wavelength of 475 nm or less, and even more preferably an absorption wavelength of 450 nm or less. Matching the absorption characteristics of the maleimide compound with the wavelength of light generated by the photon upconversion mechanism can increase the efficiency of the polymerization reaction. When the characteristic (a) is satisfied, the polymerizable compound can include a radical polymerizable compound other than the maleimide compound. Furthermore, when the characteristic (a) is satisfied, the photocurable resin composition may further contain a photopolymerization initiator (the characteristic (b)). When the characteristic (a) is satisfied, the content of the maleimide compound in the photocurable resin composition is preferably 0.1 to 100 parts by mass, and more preferably 0.2 to 100 parts by mass, relative to 100 parts by mass of all radical polymerizable compounds (i.e., the total of the maleimide compound and radical polymerizable compounds other than the maleimide compound), from the viewpoint of photoirradiation reactivity.

[0073] Photopolymerization Initiator: The photocurable resin composition satisfying characteristic (b) contains a photopolymerization initiator. A photopolymerization initiator is a reactant that absorbs light to generate active species such as radicals, cations, and anions, thereby promoting polymerization of the polymerizable compound. In one embodiment, the photopolymerization initiator is preferably a photopolymerization initiator that is activated (i.e., generates active species) by light with a wavelength of 500 nm or less. Therefore, the photopolymerization initiator is activated by light with a wavelength of 500 nm or less that is first or simultaneously irradiated onto the photocurable resin composition, and light with a wavelength of 500 nm or less that is generated by a photon upconversion mechanism by light with a wavelength of more than 500 nm that is simultaneously or subsequently irradiated. The photopolymerization initiator is more preferably activated by light with a wavelength of 450 nm or less, even more preferably by light with a wavelength of 440 nm or less, and particularly preferably by light with a wavelength of 430 nm or less. By matching the light absorption characteristics of the photopolymerization initiator with the wavelength of light generated by the photon upconversion mechanism, the efficiency of the polymerization reaction can be increased. The photopolymerization initiator can be appropriately selected from a photoradical polymerization initiator, a photoacid generator, a photobase generator, or any combination thereof.

[0074] The photoradical polymerization initiator absorbs light to generate radicals as active species, thereby promoting the polymerization of the radical polymerizable compound. Examples of the photoradical polymerization initiator include, but are not limited to, alkylphenone compounds, acylphosphine oxide compounds, oxime ester compounds, and compounds having a photosensitive moiety and a peroxide structure.

[0075] Examples of alkylphenone compounds include benzyl dimethyl ketals such as 2,2-dimethoxy-1,2-diphenylethan-1-one (commercially available as Omnirad 651 from IGM Resins B.V.); α-aminoalkylphenones such as 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one (commercially available as Omnirad 907 from IGM Resins B.V.); α-hydroxyalkylphenones such as 1-hydroxy-cyclohexyl-phenyl-ketone (commercially available as Omnirad 184 from IGM Resins B.V.); 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (commercially available as Omnirad 184 from IGM Resins B.V.); 379EG), 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (commercially available as Omnirad 369 manufactured by IGM Resins BV), etc., but are not limited to these. These may be used alone or in combination of two or more.

[0076] Examples of the acylphosphine oxide compound include, but are not limited to, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (commercially available as Omnirad TPO H manufactured by IGM Resins B.V.) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (commercially available as Omnirad 819 manufactured by IGM Resins B.V.). These compounds may be used alone or in combination of two or more.

[0077] Examples of oxime ester compounds include, but are not limited to, 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)] (trade name: Irgacure OXE-01, manufactured by BASF), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) (trade name: Irgacure OXE-02, manufactured by BASF), methanone, ethanone, 1-[9-ethyl-6-(1,3-dioxolane, 4-(2-methoxyphenoxy)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) (trade name: ADEKA OPT-N-1919, manufactured by ADEKA Corporation). These compounds may be used alone or in combination of two or more.

[0078] Examples of compounds having a photosensitive moiety and a peroxide structure or commercially available products thereof include 3,3′,4,4′-tetrakis(tert-butylperoxycarbonyl)benzophenone (BTTB), Perdual TA, and Perdual TX (all manufactured by NOF Corporation), but are not limited to these.

[0079] In addition to the above-mentioned photoradical polymerization initiators, examples of the photoradical polymerization initiator include 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-morpholinopropan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin phenyl ether, and benzyl dimethyl Examples of the benzoxanthone include, but are not limited to, ketals, 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, benzyl, camphorquinone, etc. These may be used alone or in combination of two or more.

[0080] The photoradical polymerization initiators may be used alone or in combination of two or more.

[0081] From the viewpoint of photoirradiation reactivity, the content of the photoradical polymerization initiator in the photocurable resin composition is preferably 0.1 to 10 parts by mass, and more preferably 0.2 to 8 parts by mass, relative to 100 parts by mass of the total of the radical polymerizable compounds.

[0082] The photoacid generator absorbs light to generate an acid as an active species, which promotes the polymerization of the cationic polymerizable compound. ４ － , SbF６ -, AsF ６ － , B(C ６ F ５ ) ４ － , Ga(C ６ F ５ ) ４ － , C(CF ３ SO ２ ) ３ － , [P(R １ ) ａ F ６－ａ ] － , [C(R １ SO ２ ) ３ ] － , or [N(R １ SO ２ ) ２ ] － (In the formula, R １ are each independently an alkyl group in which at least a portion of the hydrogen atoms is substituted with a fluorine atom, a is an integer of 0 to 5, and when a is an integer of 2 or more, a plurality of R １ may be the same or different.) as a counter anion, and an iodonium cation, a sulfonium cation, an ammonium cation, a phosphonium cation, or the like as a cation moiety.

[0083] Examples of iodonium cations include iodonium ions such as diphenyliodonium, di-p-tolyliodonium, bis(4-dodecylphenyl)iodonium, bis(4-methoxyphenyl)iodonium, (4-octyloxyphenyl)phenyliodonium, bis(4-decyloxy)phenyliodonium, 4-(2-hydroxytetradecyloxy)phenylphenyliodonium, 4-isopropylphenyl(p-tolyl)iodonium, and 4-isobutylphenyl(p-tolyl)iodonium.

[0084] Examples of sulfonium ions include triphenylsulfonium, tri-p-tolylsulfonium, tri-o-tolylsulfonium, tris(4-methoxyphenyl)sulfonium, 1-naphthyldiphenylsulfonium, 2-naphthyldiphenylsulfonium, tris(4-fluorophenyl)sulfonium, tri-1-naphthylsulfonium, tri-2-naphthylsulfonium, tris(4-hydroxyphenyl)sulfonium, 4-(phenylthio)phenyldiphenylsulfonium, 4-(p-tolylthio)phenyldi-p-tolylsulfonium, 4-(4-methoxyphenylthio)phenylbis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenylbis(4-fluorophenyl)sulfonium, phenyl)sulfonium, 4-(phenylthio)phenylbis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenyldi-p-tolylsulfonium, [4-(4-biphenylylthio)phenyl]-4-biphenylylphenylsulfonium, [4-(2-thioxanthonylthio)phenyl]diphenylsulfonium, bis[4-(diphenylsulfonio)phenyl]sulfide, bis[4-{bis[4-(2-hydroxyethoxy)phenyl]sulfonio}phenyl]sulfide, bis{4-[bis(4-fluorophenyl)sulfonio]phenyl}sulfide, bis{4-[bis(4-methylphenyl)sulfonio]phenyl}sulfide, bis{4-[bis(4-methoxyphenyl)sulfonio] phenyl} sulfide, 4-(4-benzoyl-2-chlorophenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(4-benzoyl-2-chlorophenylthio)phenyldiphenylsulfonium, 4-(4-benzoylphenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(4-benzoylphenylthio)phenyldiphenylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylsulfonium,10-Dihydroanthracen-2-yldiphenylsulfonium, 2-[(di-p-tolyl)sulfonio]thioxanthone, 2-[(diphenyl)sulfonio]thioxanthone, 4-(9-oxo-9H-thioxanthen-2-yl)thiophenyl-9-oxo-9H-thioxanthen-2-ylphenylsulfonium, 4-[4-(4-t-butylbenzoyl)phenylthio]phenyldi-p-tolylsulfonium, 4-[4-(4-t-butylbenzoyl)phenylthio]phenyl triarylsulfoniums such as 4-[4-(benzoylphenylthio)]phenyldi-p-tolylsulfonium, 4-[4-(benzoylphenylthio)]phenyldiphenylsulfonium, 5-(4-methoxyphenyl)thiaanthrenenium, 5-phenylthiaanthrenenium, 5-tolylthiaanthrenenium, 5-(4-ethoxyphenyl)thiaanthrenenium, and 5-(2,4,6-trimethylphenyl)thiaanthrenenium.

[0085] Examples of ammonium cations include pyrrolidiniums such as N,N-dimethylpyrrolidinium, N-ethyl-N-methylpyrrolidinium, and N,N-diethylpyrrolidinium; imidazoliniums such as N,N'-dimethylimidazolinium, N,N'-diethylimidazolinium, N-ethyl-N'-methylimidazolinium, 1,3,4-trimethylimidazolinium, and 1,2,3,4-tetramethylimidazolinium; tetrahydropyrimidiniums such as N,N'-dimethyltetrahydropyrimidinium; and morpholiniums such as N,N'-dimethylmorpholinium. pyridinium such as N-methylpyridinium, N-benzylpyridinium, and N-phenacylpyridinium; imidazolium such as N,N'-dimethylimidazolium; quinolium such as N-methylquinolium, N-benzylquinolium, and N-phenacylquinolium; isoquinolium such as N-methylisoquinolium; thiazonium such as benzylbenzothiazonium and phenacylbenzothiazonium; and acridium such as benzylacridium and phenacylacridium.

[0086] Examples of the phosphonium cation include tetraarylphosphoniums such as tetraphenylphosphonium, tetra-p-tolylphosphonium, tetrakis(2-methoxyphenyl)phosphonium, tetrakis(3-methoxyphenyl)phosphonium, and tetrakis(4-methoxyphenyl)phosphonium; triarylphosphoniums such as triphenylbenzylphosphonium, triphenylphenacylphosphonium, triphenylmethylphosphonium, and triphenylbutylphosphonium; and tetraalkylphosphoniums such as triethylbenzylphosphonium, tributylbenzylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, tetrahexylphosphonium, triethylphenacylphosphonium, and tributylphenacylphosphonium.

[0087] Specific examples of the iodonium salt-based photoacid generator include arsenate-based iodonium salt photoacid generators such as diphenyliodonium hexafluoroarsenate, di(4-chlorophenyl)iodonium hexafluoroarsenate, di(4-bromophenyl)iodonium hexafluoroarsenate, and phenyl(4-methoxyphenyl)iodonium hexafluoroarsenate; 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluorophosphate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium tri(pentafluoroethyl)trifluorophosphate (e.g., IK-1 manufactured by San-Apro Co., Ltd.), 4-methylphenyl-4-(2-methylpropyl)phenyliodonium hexafluorophosphate (e.g., IRGACURE (registered trademark) 250 manufactured by BASF), and bis(C １０～１４photoacid generators which are phosphate-based iodonium salts such as 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluorophosphate (for example, WPI-113 manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.); photoacid generators which are antimonate-based iodonium salts such as 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluoroantimonate (for example, WPI-116 manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.); photoacid generators which are gallate-based iodonium salts such as IK-1FG (manufactured by San-Apro Co., Ltd.); photoacid generators which are gallate-based iodonium salts such as 4-methylphenyl-4-(1-methylethyl)phenyliodonium tetrakis(pentafluorophenyl)borate and 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (for example, BLUESIL (registered trademark) PI manufactured by ELKEM SILICONES); Examples of suitable photoacid generators include, but are not limited to, borate-based iodonium salts such as 2074 and the like.

[0088] Specific examples of sulfonium salt-based photoacid generators include, but are not limited to, borate-based sulfonium salt photoacid generators (for example, San-Apro Ltd.'s product names: CPI-110B, CPI-310B, CPI-410B, etc., and IGM Resins B.V.'s product Omnirad 290, etc.), phosphate-based sulfonium salt photoacid generators (San-Apro Ltd.'s product names: CPI-210S, VC-1S, CPI-410S, etc.), and gallate-based sulfonium salt photoacid generators (San-Apro Ltd.'s product names: CPI-310FG, VC-1FG, etc.).

[0089] The photoacid generators may be used alone or in combination of two or more.

[0090] The content of the photoacid generator in the photocurable resin composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the total of the cationically polymerizable compounds.

[0091] The photobase generator absorbs light to generate a base as an active species, thereby promoting the polymerization of the anionically polymerizable compound. Examples of the photobase generator include, but are not limited to, various compounds that generate a base such as an amine, amidine, guanidine, phosphazene, or carbene.Specific examples of the photobase generator include 2-benzyl-2-(dimethylamino)-1-[4-(morpholino)phenyl]-1-butanone, 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one, 2-nitrobenzyl 4-hydroxypiperidine-1-carboxylate, 4,5-dimethoxy-2-nitrobenzyl 2,6-dimethylpiperidine-1-carboxylate, 1-(9,10-dioxo-9,10-dihydroanthracen-2-yl)ethyl cyclohexylcarbamate, 1-(9,10-dioxo-9,10-dihydroanthracen-2-yl)ethyl 1H-imidazole-1-carboxylate, 3,4,6,7,8,9-hexahydro-2H-pyrimido[1,2-a]pyrimidine-1- ammonium 2-(3-benzoylphenyl)propanoate, diaminomethaniminium 2-(3-benzoylphenyl)propanoate, (Z)-N-(((bis(dimethylamino)methylene)amino)(isopropylamino)methylene)propan-2-aminium 2-(3-benzoylphenyl)propanoate, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate, (Z)-{[bis(dimethylamino)methylidene]amino}-N-cyclohexyl(cyclohexylamino)methaniminium tetrakis(3-fluorophenyl)borate, 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidinium 2-(3-benzoylphenyl)propionate, 9-anthrylmethyl Examples of the diastereoisopropyl methyl ester include, but are not limited to, N,N-diethylcarbamate, (E)-1-piperidino-3-(2-hydroxyphenyl)-2-propen-1-one, 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate, tetramethylguanidium tetrakis(3-fluorophenyl)borate, tetramethylguanidium tetrakis(4-fluorophenyl)borate, salts containing protonated DBU and tetrakis(3-fluorophenyl)borate anions, and salts containing benzylated DBU and tetrakis(3-fluorophenyl)borate anions. These may be used alone or in combination of two or more.

[0092] The photobase generators may be used alone or in combination of two or more.

[0093] The content of the photobase generator in the photocurable resin composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the total of the anionically polymerizable compounds.

[0094] The photopolymerization initiator may be any one of a photoradical polymerization initiator, a photoacid generator, and a photobase generator, or any combination thereof.

[0095] The photocurable resin composition used in the photocurable resin composition curing method, bonding method, sealing method, and coating method of the above-described embodiments may contain optional components, such as those described below, as needed, if desired.

[0096] Filler: The photocurable resin composition used in the photocurable resin composition curing method, bonding method, sealing method, and coating method of the above-described embodiment may contain a filler to the extent that the object of this embodiment is not impaired. By containing a filler in the photocurable resin composition, the linear expansion coefficient of the cured product obtained by curing the photocurable resin composition can be reduced, improving thermal cycle resistance. Furthermore, a filler with a low elastic modulus can alleviate stress generated in the cured product, improving long-term reliability. Fillers are broadly classified into inorganic fillers and organic fillers.

[0097] The inorganic filler is not particularly limited as long as it is made of granular material formed from an inorganic material and has the effect of lowering the linear expansion coefficient when added. Examples of inorganic materials that can be used include silica, talc, alumina, aluminum nitride, calcium carbonate, aluminum silicate, magnesium silicate, magnesium carbonate, barium sulfate, barium carbonate, lime sulfate, aluminum hydroxide, calcium silicate, potassium titanate, titanium oxide, zinc oxide, silicon carbide, silicon nitride, and boron nitride. One type of inorganic filler may be used, or two or more types may be used in combination. In one embodiment, the inorganic filler may be a silica filler, as this allows for a high loading amount. The silica may be, for example, amorphous silica.

[0098] The inorganic filler may be surface-treated with a coupling agent such as a silane coupling agent, thereby allowing the thixotropic index (TI) of the resin composition to fall within an appropriate range.

[0099] The organic filler is not particularly limited, but examples thereof include organic fine particles of acrylic resin, polyolefin, polybutadiene rubber, polyvinyl alcohol, polyester, polyurethane, melamine, nylon, polyvinyl butyral, polyarylate, polymethyl methacrylate, polyethylene, polypropylene, polycarbonate, acrylic rubber, polystyrene, NBR, SBR, polytetrafluoroethylene, benzoguanamine-formaldehyde, silicone rubber, silicone-modified resin, phenol resin, and copolymers containing these as components. The organic filler may also be surface-treated.

[0100] The shape of the filler is not particularly limited, and may be any of spherical, flaky, needle-like, irregular, etc.

[0101] The average particle size of the filler is preferably 0.01 to 15 μm, more preferably 0.01 to 10 μm. From the viewpoint of the transmittance of long-wavelength light irradiated to the photocurable resin composition, the maximum particle size of the filler is preferably 50 μm or less, more preferably 30 μm or less.

[0102] In this specification, the average particle size is the particle size at an integrated value of 50% in the particle size distribution on a volume basis measured by a laser diffraction / scattering method, and the maximum particle size is the maximum particle size in the particle size distribution on a volume basis measured by a laser diffraction / scattering method.

[0103] When a filler is contained, the content of the filler is preferably 0.5 to 80% by mass, more preferably 1 to 70% by mass, based on the total mass of the photocurable resin composition.

[0104] The photocurable resin composition used in the curing method, bonding method, sealing method, and coating method of the photocurable resin composition of the above embodiment may contain a thixotropic agent to the extent that the effects of this embodiment are not impaired. Examples of thixotropic agents include silica such as colloidal silica, hydrophobic silica, fine silica, and nanosilica, as well as bentonite, acetylene black, and ketjen black. Nanosilica is preferred from the viewpoint of shape retention after application. Furthermore, from the viewpoints of preventing the resin composition from biting during bonding and moisture-resistant adhesion, nanosilica with an average particle size of 10 to 750 nm is more preferred, and nanosilica with an average particle size of 20 to 600 nm is even more preferred. Commercially available products include hydrophobic fumed silica manufactured by CABOT Corporation (product name: CAB-O-SIL (registered trademark) TS720, average particle size: 12 nm), hydrophobic fumed silica manufactured by Nippon Aerosil (product name: R805, average particle size: 20 nm), and amorphous silica manufactured by Nippon Shokubai (product name: Seahoster KE-P10, average particle size 100 nm), but are not limited to these. Here, the average particle size of the nanosilica particles is measured using a dynamic light scattering Nanotrac particle size analyzer. The thixotropic agent may be used alone or in combination of two or more types.

[0105] When a thixotropic agent is contained, the content of the thixotropic agent is preferably 0.01 to 30 mass %, more preferably 0.05 to 25 mass %, and even more preferably 0.1 to 20 mass %, relative to the total mass of the photocurable resin composition.

[0106] Light-blocking agent: The photocurable resin composition used in the photocurable resin composition curing method, bonding method, sealing method, and coating method of the above-described embodiment may contain a light-blocking agent to the extent that the effect of the present embodiment is not impaired. Light-blocking properties may be required depending on the application of the cured resin composition. In such cases, the photocurable resin composition used in the method of the above-described embodiment may contain a light-blocking agent. Long-wavelength light can be transmitted through a light-blocking agent that blocks ultraviolet light. The photocurable resin composition used in the method of the above-described embodiment can be cured internally (deeply) by irradiating it with long-wavelength light, without or with minimal influence from the light-blocking agent. Examples of light-blocking agents include, but are not limited to, carbon black and titanium black. These light-blocking agents can also be used as light-to-heat conversion materials that convert long-wavelength light into heat.

[0107] Other Additives The photocurable resin composition used in the curing method, bonding method, sealing method, and coating method of the photocurable resin composition of the above-described embodiment may further contain other additives, such as photosensitizers, conductive fillers, stabilizers, radical polymerization inhibitors, anionic polymerization inhibitors, coupling agents, ion trapping agents, leveling agents, antioxidants, antifoaming agents, viscosity modifiers, flame retardants, colorants, plasticizers, and solvents, if desired, within the scope of the present embodiment. The type and amount of each additive are conventional. The resin composition used in the curing method, bonding method, sealing method, and coating method of the photocurable resin composition of the above-described embodiment is substantially free of liquid components such as water, solvents, and ionic liquids (excluding liquid polymerizable compounds, photon upconversion materials, and photopolymerization initiators), from the viewpoints of reducing curing strength and adhesion upon photocuring and preventing outgassing and bleeding. For example, the content of liquid components is preferably 3% by mass or less, and more preferably 1% by mass or less, relative to the total mass of the resin composition. Examples of the solvent include organic solvents commonly used in the field of curable compositions, such as hydrocarbons (benzene, toluene, xylene, cyclohexane, etc.), aprotic polar solvents (N,N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, etc.), nitriles (acetonitrile, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), esters (ethyl acetate, butyl acetate, etc.), ethers (cyclopentyl methyl ether, diethyl ether, tetrahydrofuran, dimethoxyethane, etc.), alcohols (methanol, ethanol, propanol, butanol, etc.), terpenes (turpentine, terpineol, isobornyl acetate, etc.), and halogenated solvents (dichloromethane, chloroform, etc.).

[0108] The viscosity of the photocurable resin composition used in the photocurable resin composition curing method, bonding method, sealing method, and coating method of the above-described embodiments is preferably 0.1 to 100 Pa·s. The viscosity can be adjusted appropriately depending on the application and application location of the resin composition. In this specification, viscosity is expressed as a value measured in accordance with Japanese Industrial Standard JIS K6833, unless otherwise specified. Specifically, it can be determined by measuring using an E-type viscometer at a rotation speed of 10 rpm. There are no particular limitations on the equipment, rotor, or measurement range used.

[0109] The method for producing the photocurable resin composition used in the curing method, bonding method, sealing method, and coating method of the above-described embodiment of the photocurable resin composition is not particularly limited. For example, the polymerizable compound, photon upconversion material, and other optional components can be simultaneously or separately introduced into an appropriate mixer and stirred to mix them into a uniform composition, thereby obtaining the resin composition used in the above-described embodiment of the method. The mixer is not particularly limited, and examples of the mixer that can be used include a Raikai mixer, a Henschel mixer, a three-roll mill, a ball mill, a planetary mixer, and a bead mill equipped with a stirring device and a heating device. These devices may also be used in appropriate combinations.

[0110] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, parts and % represent parts by mass and % by mass unless otherwise specified.

[0111] [Production of Photocurable Resin Composition] A photocurable resin composition was prepared by mixing the specified amounts of each component according to the formulation shown below. This photocurable resin composition was used in the following tests. Polymerizable compound: Dimethylol-tricyclodecane diacrylate (product name: Light Acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd.). The content was 97.75 mass% in the resin composition. Photon upconversion material: Platinum(II) octaethylporphyrin (PtOEP) (manufactured by Sigma-Aldrich Japan) as the donor; Diphenylanthracene (DPA) (manufactured by Tokyo Chemical Industry Co., Ltd.) as the acceptor. The mass ratio of the donor and acceptor, PtOEP:DPA, was 1:24 (molar ratio 1:50), and the mixture was used as the photon upconversion material. The content was 0.25 mass% in the resin composition. Photopolymerization initiator: 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (product name: Omnirad 379EG, manufactured by IGM Resins BV) The content was 2.0 mass % in the resin composition.

[0112] [Preparation of Test Sample] Four strips of heat-resistant tape (150 μm thick) were attached to a black resin plate (50 mm wide x 25 mm long x 1.5 mm thick) at 2 mm intervals. The photocurable resin composition prepared as described above was applied to the three paths (2 mm wide x 25 mm long x 150 μm thick) between the four strips of heat-resistant tape to the same thickness as the heat-resistant tape. Another resin plate was placed on top of the four strips and clipped at both ends to form a test sample with four strips of heat-resistant tape and three strips of photocurable resin composition sandwiched between the two resin plates. Any photocurable resin composition that spilled over from the resin plate was wiped off.

[0113] [Example 1] The photocurable resin composition prepared as described above was irradiated with ultraviolet light from above, followed by visible light irradiation. The ultraviolet light irradiation conditions were as follows: ultraviolet light with a wavelength of 365 nm, ultraviolet light dose of 2000 mJ / cm, using a single-wavelength UV LED light source (OmniCure (registered trademark) AC475, manufactured by Excelitas Technologies). ２The visible light irradiation conditions were as follows: a semiconductor pumped solid-state laser (Class 3R green laser pointer LP-GL1016BK, manufactured by Sanwa Supply Co., Ltd.) was used to irradiate visible light with a wavelength of 532 nm and ultraviolet light with an irradiation dose of 5000 mJ / cm. ２ One of the sandwiched resin plates was peeled off, the uncured portion adhering to the cured product was removed, and the length of the cured portion was measured using a measuring microscope. In Example 1, in which ultraviolet light irradiation and then visible light irradiation were performed, the surface and deep portions of the resin composition were effectively cured, and the length of the cured portion was 1,300 μm. Similar results were obtained when ultraviolet light irradiation and visible light irradiation were performed simultaneously.

[0114] Comparative Example 1: The photocurable resin composition prepared as described above was irradiated with ultraviolet light alone from above. The ultraviolet light irradiation conditions were as follows: ultraviolet light with a wavelength of 365 nm, ultraviolet light dose of 2000 mJ / cm, using a single-wavelength UV LED light source (OmniCure (registered trademark) AC475, manufactured by Excelitas Technologies). ２ One of the sandwiched resin plates was peeled off, the uncured portion adhering to the cured product was removed, and the length of the cured portion was measured using a measuring microscope. In Comparative Example 1, in which only ultraviolet light irradiation was performed, curing of the deep part of the resin composition did not proceed effectively, and the length of the cured portion was 400 μm.

[0115] [Comparative Example 2] The photocurable resin composition prepared as above was irradiated with only visible light from above. The visible light irradiation conditions were a semiconductor pumped solid-state laser (Class 3R green laser pointer LP-GL1016BK, manufactured by Sanwa Supply Co., Ltd.) with visible light having a wavelength of 532 nm and an ultraviolet light irradiation dose of 5000 mJ / cm. ２ One of the sandwiched resin plates was peeled off, the uncured portion adhering to the cured product was removed, and the length of the cured portion was measured using a measuring microscope. In Comparative Example 2, in which only visible light irradiation was performed, curing of the surface of the resin composition did not proceed effectively, and the length of the cured portion was 1000 μm.

[0116] The disclosure of Japanese Patent Application No. 2024-116919 (filing date: July 22, 2024) is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A method for curing a photocurable resin composition, comprising the steps of: irradiating a photocurable resin composition containing a polymerizable compound with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm, simultaneously or sequentially, under atmospheric conditions, and polymerizing the polymerizable compound using at least a photon upconversion mechanism.

2. A method for bonding at least two components using a photocurable resin composition, comprising the steps of: applying a photocurable resin composition containing a polymerizable compound to at least one of the at least two components; attaching the other component to the component coated with the photocurable resin composition via the photocurable resin composition, or attaching the component coated with the photocurable resin composition to the other component via the photocurable resin composition; and irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm, simultaneously or sequentially, under atmospheric conditions, to polymerize the polymerizable compound using at least a photon upconversion mechanism.

3. A method for sealing gaps between or within components with a photocurable resin composition, comprising the steps of: applying or injecting a photocurable resin composition containing a polymerizable compound into the gaps between or within the components; and irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm simultaneously or sequentially under atmospheric conditions, thereby polymerizing the polymerizable compound using at least a photon upconversion mechanism.

4. A method for coating the surface of an object with a photocurable resin composition, comprising: a step of applying a photocurable resin composition containing a polymerizable compound to the object; and a step of irradiating the photocurable resin composition with light having a wavelength of 500 nm or less and light having a wavelength of more than 500 nm simultaneously or sequentially under atmospheric conditions, thereby polymerizing the polymerizable compound using at least a photon upconversion mechanism.

5. The method according to any one of claims 1 to 4, wherein the photocurable resin composition comprises a photon upconversion material.

6. The method of claim 5, wherein the emission wavelength of the photon upconversion material includes wavelengths of 500 nm or less.

7. The method according to any one of claims 1 to 6, wherein the photocurable resin composition satisfies at least one of the following characteristics (a) and (b): (a) the polymerizable compound includes a maleimide compound; (b) the photocurable resin composition further includes a photopolymerization initiator.

8. The method according to any one of claims 2, 3, and 5 to 7, wherein the component is a component constituting a semiconductor device or an electronic component.

9. The method according to any one of claims 4, 5 to 7, wherein the object is a semiconductor device or an electronic component, or a component that constitutes these.

10. A cured product obtained by the curing method according to any one of claims 1, 5 to 7.