Photopolymerization initiator composition, photocurable composition, photocurable composition kit and photocurable resin composition

Abstract

The purpose of the present invention is to provide: a photopolymerization initiator composition which is capable of suppressing bleeding onto the surface of a cured product and which is capable of initiating a radical polymerization reaction with a low irradiation dose; a photocurable composition containing the photopolymerization initiator composition; a photocurable composition set; and a photocurable resin composition. The photopolymerization initiator composition according to the present invention contains: a hydrogen abstracting type photopolymerization initiator having one or more functional groups containing an ethylenically unsaturated double bond; the monomer (A) has one or more functional groups containing an ethylenically unsaturated double bond and at least one hydrogen-donating group selected from the group consisting of a formal group, a tertiary amino group, a thioether group, and a nitrogen-containing heterocyclic ring.

Description

Technical Field

[0001] The present invention relates to a photopolymerization initiator composition, and a photocurable composition, a photocurable composition kit and a photocurable resin composition comprising the photopolymerization initiator composition. Background Art

[0002] A photocurable composition containing a photopolymerization initiator and a monomer component is widely used in, for example, coating materials, inks, adhesives, pressure-sensitive adhesives, insulating films, protective films, and films.

[0003] However, conventionally, there has been a problem that the photopolymerization initiator or its decomposition product bleeds out in the cured product of the above-mentioned photocurable composition.

[0004] In order to solve this problem, photopolymerization initiators having an ethylenically unsaturated double bond and capable of being incorporated into a polymer structure have been proposed (for example, Patent Documents 1 and 2).

[0005] In addition, Patent Document 3 proposes a UV-crosslinking acrylic adhesive with improved photopolymerization efficiency, wherein the UV-crosslinking acrylic adhesive is produced by subjecting a copolymer generated by solution polymerizing a mixture of a benzophenone derivative containing an unsaturated group, an acrylic monomer containing a hydrogen-donating group, and at least one monomer that is polymerized into a high molecule to crosslinking by exposing it to UV light.

[0006] Furthermore, Patent Document 4 proposes a photocurable adhesive precursor composition comprising an ethylenically unsaturated monomer, a prepolymer having a monomer unit derived from a hydrogen-donating monomer, and a hydrogen-abstracting photoinitiator for the purpose of obtaining a photocurable adhesive having sufficient heat resistance without undergoing a aging process.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 62-81345

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 2-305847

[0011] Patent Document 3: Japanese Patent Application Publication No. 2006-144014

[0012] Patent Document 4: Japanese Patent Application Publication No. 2017-193601 Summary of the invention

[0013] However, Patent Document 3 uses 2-hydroxyethyl methacrylate as an acrylic monomer containing a hydrogen-donating group, so a significant improvement in photopolymerization efficiency cannot be expected. In addition, Patent Document 4 incorporates a hydrogen-donating monomer into the prepolymer structure in advance, so hydrogen abstraction is not likely to occur, and it is expected that the reactivity of free radical polymerization will not be significantly improved. It should be noted that Patent Document 4 does not record the incorporation of a hydrogen-abstracting photoinitiator into the polymer structure.

[0014] The present invention is made in view of the above-mentioned problems, and its purpose is to provide a photopolymerization initiator composition that can inhibit bleeding to the surface of a cured product and can initiate a free radical polymerization reaction at a low irradiation dose, as well as a photocurable composition, a photocurable composition kit and a photocurable resin composition containing the photopolymerization initiator composition.

[0015] The present inventors have conducted intensive studies to solve the above-mentioned problems and, as a result, have found that the above-mentioned problems can be solved by the following photopolymerization initiator composition and photocurable composition, thereby completing the present invention.

[0016] That is, the present invention provides the following aspects of the invention.

[0017] [1]. A photopolymerization initiator composition comprising a hydrogen abstraction type photopolymerization initiator and a monomer A,

[0018] The hydrogen abstraction type photopolymerization initiator has one or more functional groups containing an ethylenically unsaturated double bond.

[0019] The monomer A has one or more functional groups containing an ethylenically unsaturated double bond and at least one hydrogen-donating group selected from the group consisting of a formal group, a tertiary amino group, a thioether group and a nitrogen-containing heterocyclic ring.

[0020] [2] The photopolymerization initiator composition according to [1], wherein the hydrogen abstraction type photopolymerization initiator is at least one selected from the group consisting of a benzophenone type photopolymerization initiator, a xanthone type photopolymerization initiator, a thioxanthone type photopolymerization initiator and an acridone type photopolymerization initiator.

[0021] [3] The photopolymerization initiator composition according to [1] or [2], wherein the functional group containing an ethylenically unsaturated double bond of the hydrogen abstraction type photopolymerization initiator is a (meth)acryloyloxy group.

[0022] [4] The photopolymerization initiator composition according to any one of [1] to [3], wherein the functional group containing an ethylenically unsaturated double bond possessed by the above-mentioned monomer A is a (meth)acryloyl group or a (meth)acryloyloxy group, and the above-mentioned monomer A has a formal group or a tertiary amino group.

[0023] [5]. The photopolymerization initiator composition according to any one of [1] to [4], wherein the functional group containing an ethylenically unsaturated double bond of the hydrogen abstraction type photopolymerization initiator is an acryloyloxy group, and the functional group containing an ethylenically unsaturated double bond of the monomer A is an acryloyl group or an acryloyloxy group.

[0024] [6] A photocurable composition comprising the photopolymerization initiator composition according to any one of [1] to [5] and a base monomer B.

[0025] [7] The photocurable composition according to [6], wherein the photocurable composition is an ultraviolet curable inkjet ink.

[0026] [8] A photocurable composition kit comprising the photopolymerization initiator composition according to any one of [1] to [5] and a base monomer composition, wherein the base monomer composition contains a base monomer B.

[0027] [9]. A photocurable resin composition comprising the photopolymerization initiator composition according to any one of [1] to [5] and a resin component.

[0028]

[10] . A photocurable resin composition comprising the photocurable composition described in [6] and a resin component.

[0029] Since the hydrogen abstraction type photopolymerization initiator of the present invention has one or more functional groups containing ethylenically unsaturated double bonds, it is different from general hydrogen abstraction type photopolymerization initiators and has the characteristic of being able to be incorporated into the polymer structure. Therefore, it is possible to effectively inhibit the photopolymerization initiator or its modified product remaining in the cured product from seeping out to the surface of the cured product. On the other hand, the monomer A of the present invention has at least one hydrogen-donating group selected from a formal group, a tertiary amino group, a thioether group and a nitrogen-containing heterocycle, and the stability of the carbon radicals generated in the above hydrogen-donating group is high. Therefore, it has the characteristics of being easy to undergo hydrogen abstraction based on the above hydrogen abstraction type photopolymerization initiator and easy to generate highly reactive carbon radicals. Since the photopolymerization initiator composition of the present invention contains the hydrogen abstraction type photopolymerization initiator and the above monomer A, it is possible to effectively inhibit seepage to the surface of the cured product and to initiate a free radical polymerization reaction at a low irradiation dose. In addition, since the photopolymerization initiator composition of the present invention has the above-mentioned characteristics, it can be suitably used as a photopolymerization initiator component to be blended into a photocurable composition (e.g., ultraviolet curable inkjet ink and coating), a photocurable composition kit (e.g., a two-component adhesive and a two-component adhesive), and a photocurable resin composition (e.g., a photosensitive resin composition, a resin composition for a hard coat, a resin composition for an insulating film, an adhesive composition, and an adhesive composition). In addition, the photopolymerization initiator composition of the present invention has a function not only as a photopolymerization initiator component but also as a monomer component or a crosslinking component. DETAILED DESCRIPTION

[0030] In the present invention, (meth)acrylate refers to acrylate and / or methacrylate, (meth)acryloyl refers to acryloyl and / or methacryloyl, and (meth)acrylic acid refers to acrylic acid and / or methacrylic acid.

[0031] <Photopolymerization initiator composition>

[0032] The photopolymerization initiator composition of the present invention contains a hydrogen-abstracting photopolymerization initiator and a monomer A (hereinafter also referred to as "hydrogen-donating monomer A"). The hydrogen-abstracting photopolymerization initiator has one or more functional groups containing ethylenically unsaturated double bonds, and the monomer A has one or more functional groups containing ethylenically unsaturated double bonds and at least one hydrogen-donating group selected from a formal group, a tertiary amino group, a thioether group and a nitrogen-containing heterocycle.

[0033] 〔Hydrogen abstraction type photopolymerization initiator〕

[0034] The hydrogen abstraction type photopolymerization initiator in the present invention refers to a photopolymerization initiator that can be excited by light irradiation to a high energy state, thereby abstracting a hydrogen atom from the hydrogen donating group of the hydrogen donating monomer A to generate a carbon radical from the hydrogen donating group.

[0035] In order to be incorporated into the polymer structure, the hydrogen abstraction type photopolymerization initiator has one or more functional groups containing ethylenically unsaturated double bonds (hereinafter also referred to as "free radical polymerizable functional groups"). There are no particular restrictions on the free radical polymerizable functional groups, and examples thereof include vinyl, allyl, styryl, (meth)acryloyl, (meth)acryloyloxy and (meth)acrylamide groups. From the viewpoint of improving polymerization reactivity, (meth)acryloyloxy is preferred, and acryloyloxy is more preferred. The hydrogen abstraction type photopolymerization initiator may have one free radical polymerizable functional group, or may have two or more. In addition, the hydrogen abstraction type photopolymerization initiator preferably has 1 to 3 free radical polymerizable functional groups, more preferably 1 or 2, and further preferably 1.

[0036] The hydrogen abstraction type photopolymerization initiator has one or more free radical polymerizable functional groups, and generates carbon free radicals by the reaction between the ketone group excited by light irradiation and the hydrogen atom abstracted from the hydrogen donating group of the hydrogen donating monomer A. Therefore, it not only functions as a photopolymerization initiator but also functions as a monomer component or a cross-linking component.

[0037] The hydrogen abstraction type photopolymerization initiator is preferably selected from at least one of benzophenone type photopolymerization initiators, xanthone type photopolymerization initiators, thioxanthone type photopolymerization initiators and acridone type photopolymerization initiators, more preferably benzophenone type photopolymerization initiators. In these types of photopolymerization initiators, the free radical polymerizable functional group can be bonded to any position in the ortho position, meta position or para position relative to the ketone group, but from the viewpoint of ease of manufacture, it is preferably bonded to the ortho position or para position. In addition, in these types of photopolymerization initiators, the free radical polymerizable functional group can be directly bonded to the benzene ring, or it can be bonded via organic groups such as aliphatic hydrocarbon groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, but from the viewpoint of improving polymerization reactivity, it is preferably directly bonded to the benzene ring. In addition, in these types of photopolymerization initiators, the benzene ring can have more than one substituent such as alkyl, alkoxy and halogen groups.

[0038] The hydrogen abstraction type photopolymerization initiator is preferably a photopolymerization initiator of the following structure. One or more of them may be used. The photopolymerization initiator of the following structure may be synthesized, for example, by reacting a hydroxyl group-containing benzophenone, a hydroxyl group-containing xanthone, a hydroxyl group-containing thioxanthone or a hydroxyl group-containing acridone with (meth) acrylic anhydride.

[0039]

[0040] (Where R 1 and R 2 are each independently hydrogen or methyl)

[0041] 〔Hydrogen donating monomer A〕

[0042] The hydrogen-donating monomer A has one or more free radical polymerizable functional groups. There is no particular limitation on the free radical polymerizable functional groups, and examples thereof include vinyl, allyl, styryl, (meth)acryloyl, (meth)acryloyloxy and (meth)acrylamide. From the viewpoint of initiating free radical polymerization reaction at a low irradiation dose, (meth)acryloyl or (meth)acryloyloxy is preferred, and acryloyl or acryloyloxy is more preferred. The hydrogen-donating monomer A may have one free radical polymerizable functional group, or may have two or more. In addition, the hydrogen-donating monomer A preferably has 1 to 3 free radical polymerizable functional groups, more preferably 1 or 2, and further preferably 1.

[0043] The hydrogen-donating monomer A has at least one hydrogen-donating group selected from a formal group, a tertiary amino group, a thioether group, and a nitrogen-containing heterocycle. These hydrogen-donating groups are excellent in hydrogen-donating properties compared to hydroxyl groups, thiol groups, ether groups, primary amino groups, secondary amino groups, amide groups, or oxygen-containing heterocycles, and are easy to produce highly reactive carbon free radicals, so compared with existing hydrogen-donating monomers, free radical polymerization can be initiated with a low irradiation dose. From the viewpoint that the hydrogen-donating property is more excellent and carbon free radicals are more easily produced, the hydrogen-donating monomer A preferably has a formal group or a tertiary amino group, and from the viewpoint that the influence on the human body is smaller and the coloring of the cured product is effectively suppressed, it is more preferably a formal group.

[0044] The formal group is a group having a methylene group between two oxygen atoms, and may be a cyclic structure (hereinafter also referred to as a "cyclic formal group") or a chain structure (hereinafter also referred to as a "chain formal group"). Examples of the cyclic formal group include 1,3-dioxetane ring, 1,3-dioxetane ring, Cyclopentane ring, 1,3-dicarboxylic acid Alkane ring, 1,3,5-tri Alkane ring, 1,3-benzodione Cyclopentadiene and 1,3-benzophenone As the chain formal group, for example, there can be mentioned -R 3 -O-CH 2 -OR 4 Structure or -R 3 -O-CH 2 -OR 5 - structure. 3 and R 5 Each independently represents a single bond or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably a single bond or an aliphatic hydrocarbon group having 1 to 6 carbon atoms, more preferably a single bond or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and still more preferably a single bond or an aliphatic hydrocarbon group having 1 or 2 carbon atoms. 4It is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, more preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and further preferably an aliphatic hydrocarbon group having 1 or 2 carbon atoms.

[0045] The tertiary amino group is not particularly limited, and examples thereof include tertiary amino groups having an aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably a tertiary amino group having an aliphatic hydrocarbon group having 1 to 6 carbon atoms, more preferably a tertiary amino group having an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and further preferably a tertiary amino group having an aliphatic hydrocarbon group having 1 or 2 carbon atoms.

[0046] The thioether group is not particularly limited, and examples thereof include -R 6 -SR 7 Structure or -R 6 -SR 8 - structure. 6 ~R 8 Each independently is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, more preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and further preferably an aliphatic hydrocarbon group having 1 or 2 carbon atoms.

[0047] The nitrogen-containing heterocyclic ring is not particularly limited as long as it is a heterocyclic ring having one or more nitrogen atoms, and examples thereof include aziridine ring, azetidine ring, pyrrolidine ring, pyrroline ring, piperidine ring, azepane ring, imidazolidine ring, imidazoline ring, pyrazolidine ring, pyrazoline ring, Oxazolidine ring, thiazolidine ring, piperazine ring, morpholine ring, thiomorpholine ring, triazacyclohexane ring, azaadamantane ring and hexamethylenetetramine ring, etc.

[0048] The hydrogen-donating monomer A has one or more radical polymerizable functional groups and generates carbon radicals on the hydrogen-donating groups by abstracting hydrogen, and therefore also functions as a crosslinking component.

[0049] The hydrogen-donating monomer A is preferably trialkanolamine tri(meth)acrylate (the number of carbon atoms in the alkanol group is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 4, particularly preferably 1 or 2) and the following compounds. These may be used alone or in combination of two or more.

[0050]

[0051] (Where R 1 is hydrogen or methyl, R 4 , R 6 , R 7 and R 9 ~R 11Each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, more preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and further preferably an aliphatic hydrocarbon group having 1 or 2 carbon atoms)

[0052] From the viewpoint of initiating free radical polymerization reaction with a low irradiation dose, the free radical polymerizable functional group possessed by the hydrogen abstraction type photopolymerization initiator and the free radical polymerizable functional group possessed by the hydrogen donating monomer A are preferably the same functional group or the same type of functional group, more preferably the free radical polymerizable functional group possessed by the hydrogen abstraction type photopolymerization initiator is a (meth)acryloyloxy group, and the free radical polymerizable functional group possessed by the hydrogen donating monomer A is a (meth)acryloyl group or a (meth)acryloyloxy group, and particularly preferably the free radical polymerizable functional group possessed by the hydrogen abstraction type photopolymerization initiator is an acryloyloxy group, and the free radical polymerizable functional group possessed by the hydrogen donating monomer A is an acryloyl group or an acryloyloxy group.

[0053] In the photopolymerization initiator composition of the present invention, from the viewpoint of initiating a free radical polymerization reaction at a low irradiation dose, the molar ratio of the hydrogen abstraction type photopolymerization initiator to the hydrogen donating monomer A (hydrogen abstraction type photopolymerization initiator: hydrogen donating monomer A) is preferably 1:5 to 5:1, more preferably 1:4 to 4:1, and further preferably 1:3 to 3:1. In addition, as one embodiment of the photopolymerization initiator composition of the present invention, the molar ratio (hydrogen abstraction type photopolymerization initiator: hydrogen donating monomer A) is preferably 1:2 to 1:5, and more preferably 1:3 to 1:4.

[0054] The photopolymerization initiator composition of the present invention may contain a photopolymerization initiator other than the hydrogen abstraction type photopolymerization initiator, a photopolymerization initiation aid, a solvent, and the like, as necessary.

[0055] In the photopolymerization initiator composition of the present invention, the total content of the hydrogen abstraction type photopolymerization initiator and the hydrogen donating monomer A is usually 1 to 100 mass %, preferably 10 to 80 mass %, and more preferably 20 to 50 mass %.

[0056] The photopolymerization initiator composition of the present invention can suppress bleeding to the surface of the cured product and coloring of the cured product, and can initiate a free radical polymerization reaction at a low irradiation dose, and therefore can be used as a photopolymerization initiator component for a photocurable composition (e.g., ultraviolet curable inkjet ink and coating, etc.), a photocurable composition kit (e.g., a two-component adhesive and a two-component adhesive, etc.), and a photocurable resin composition (e.g., a photosensitive resin composition, a resin composition for a hard coat, a resin composition for an insulating film, an adhesive composition, and an adhesive composition, etc.). In addition, the photopolymerization initiator composition of the present invention has a role not only as a photopolymerization initiator component, but also as a monomer component or a crosslinking component.

[0057] <Photocurable composition>

[0058] The photocurable composition of the present invention contains the photopolymerization initiator composition and the base monomer B described above.

[0059] The base monomer B is a main monomer for forming a polymer, and examples thereof include monofunctional monomers and polyfunctional monomers.

[0060] Examples of the monofunctional monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Alkyl (meth)acrylates such as decyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, isostearyl (meth)acrylate, eicosyl (meth)acrylate and behenyl (meth)acrylate; cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate and propylene (meth)acrylate; alicyclic (meth)acrylates such as adamantyl (meth)acrylate; heterocyclic (meth)acrylates such as glycidyl (meth)acrylate and tetrahydrofurfuryl (meth)acrylate; alkoxy-containing (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate and nonylphenyl carbitol (meth)acrylate; hydroxyl-containing (meth)acrylates such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate; benzyl (meth)acrylate and (meth)acrylate. (Meth)acrylates containing aromatic groups, such as phenoxyethyl acrylate; (meth)acrylic acid, 2-(meth)acryloyloxyethyl succinate, maleic acid, and itaconic acid; monomers containing carboxyl groups, such as maleic anhydride and itaconic anhydride; styrene derivatives, such as styrene and methylstyrene; maleimide derivatives, such as cyclohexylmaleimide, phenylmaleimide, methylmaleimide, ethylmaleimide, n-butylmaleimide, and laurylmaleimide; N-vinylpyrrolidone, vinyl acetate, vinyl acetate, etc. These can be used alone or in combination of two or more.

[0061] As the multifunctional monomer, for example, divinylbenzene, diallyl phthalate and diallylphenylphosphonate and other multifunctional aromatic vinyl monomers can be cited; (di) ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and tri(hydroxyethyl)isocyanurate tri(meth)acrylate and other multifunctional (meth)acrylates, etc. These can be used alone or in combination of two or more.

[0062] In the photocurable composition of the present invention, the content of the base monomer B is generally about 5 to 95% by mass, preferably 10 to 90% by mass, and more preferably 50 to 80% by mass.

[0063] In the photocurable composition of the present invention, the content of the photopolymerization initiator composition is usually about 5 to 95% by mass, preferably 10 to 90% by mass, and more preferably 20 to 50% by mass from the viewpoint of imparting sufficient reactivity and exerting the function of the base monomer B.

[0064] In the photocurable composition of the present invention, from the viewpoint of imparting sufficient reactivity and exerting the function from the base monomer B, the content of the base monomer B is preferably in a molar ratio of the total content of the hydrogen abstracting photopolymerization initiator and the hydrogen donating monomer A in the photopolymerization initiator composition, the content of the base monomer B: the total content of the hydrogen abstracting photopolymerization initiator and the hydrogen donating monomer A in the photopolymerization initiator composition = 40 to 95:60 to 5, more preferably 50 to 90:50 to 10, and further preferably 55 to 85:45 to 15.

[0065] The photocurable composition of the present invention may contain a photopolymerization initiator other than the hydrogen abstraction type photopolymerization initiator, a radical polymerizable oligomer such as unsaturated polyester, epoxy acrylate, urethane acrylate and polyester acrylate, a photopolymerization initiation aid, a solvent and the like as necessary.

[0066] When the photocurable composition of the present invention is an ultraviolet curable inkjet ink or coating, it may contain known components such as a sensitizer, a sensitizing aid, a colorant (pigment, dye), a dispersant, a slip agent (surfactant), a wetting agent (humectant), a surface modifier, an antioxidant, an ultraviolet absorber, a chelating agent, a pH adjuster and a stabilizer as needed.

[0067] <Photocurable composition kit>

[0068] The photocurable composition kit of the present invention comprises at least the above-mentioned photopolymerization initiator composition and a base monomer composition, and the above-mentioned base monomer composition contains a base monomer B.

[0069] The base monomer B is a main monomer for forming a polymer, and examples thereof include the above-mentioned monofunctional monomers and the above-mentioned polyfunctional monomers, which may be used alone or in combination of two or more.

[0070] The content of the base monomer B in the base monomer composition is generally about 5 to 95% by mass, preferably 10 to 90% by mass, and more preferably 50 to 80% by mass.

[0071] The base monomer composition may contain a photopolymerization initiator other than the hydrogen abstraction type photopolymerization initiator, a radical polymerizable oligomer such as unsaturated polyester, epoxy acrylate, urethane acrylate, and polyester acrylate, a photopolymerization initiation aid, a solvent, and the like, as necessary.

[0072] Examples of the photocurable composition kit of the present invention include two-component adhesives and two-component pressure-sensitive adhesives.

[0073] <Photocurable resin composition>

[0074] The photocurable resin composition of the present invention contains the above-mentioned photopolymerization initiator composition or the above-mentioned photocurable composition and a resin component. That is, as representative examples of the photocurable resin composition, there can be cited (1) a form containing a photopolymerization initiator composition and a resin component, and (2) a form containing a photopolymerization initiator composition, a base monomer B, and a resin component.

[0075] The resin component needs to be appropriately selected depending on the purpose of the photocurable resin composition. For example, in the case of a photosensitive resin composition, a known alkali-soluble resin can be used, in the case of a resin composition for a hard coat or a resin composition for an insulating film, a known curable resin can be used, and in the case of an adhesive composition or a bonding agent composition, a known base polymer can be used.

[0076] The content of the resin component in the photocurable resin composition of the present invention needs to be appropriately adjusted depending on the application of the photocurable resin composition, and is usually about 5 to 95% by mass, preferably 10 to 90% by mass, and more preferably 50 to 80% by mass.

[0077] In the photocurable resin composition of the present invention, the content of the photopolymerization initiator composition needs to be appropriately adjusted depending on the application of the photocurable resin composition, and is usually about 5 to 95% by mass, preferably 10 to 90% by mass, and more preferably 20 to 50% by mass.

[0078] The content of the photocurable resin composition of the present invention needs to be appropriately adjusted depending on the application of the photocurable resin composition, and is usually about 5 to 95% by mass, preferably 10 to 90% by mass, and more preferably 20 to 50% by mass.

[0079] The photocurable resin composition of the present invention may contain a radical polymerizable oligomer such as an unsaturated polyester, epoxy acrylate, urethane acrylate, and polyester acrylate, a photopolymerization initiation aid, a solvent, and the like, as necessary.

[0080] The photocurable resin composition of the present invention may contain fillers such as aluminum hydroxide, talc, clay, barium sulfate, crosslinking agents, dyes, pigments, defoamers, coupling agents, leveling agents, sensitizers, release agents, lubricants, plasticizers, stabilizers, antioxidants, ultraviolet absorbers, flame retardants, polymerization inhibitors, tackifiers, adhesion-imparting agents, dispersants and other known additives as needed.

[0081] Examples of the photocurable resin composition of the present invention include a photosensitive resin composition, a resin composition for a hard coat layer, a resin composition for an insulating film, a binder composition, and an adhesive composition.

[0082] <Cured product>

[0083] Examples of the cured product obtained by curing the photocurable composition, photocurable composition kit or photocurable resin composition of the present invention include lenses (microlenses), photoresist spacers, partition materials, insulating films, protective films, hard coating layers, films, optical waveguide materials, planarizing film materials, adhesive layers and adhesive layers.

[0084] Example

[0085] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0086] Example 1

[0087] In a 30 mL glass container, 80 mol parts of isobornyl acrylate (IBXA) as a base monomer B, 10 mol parts of 4-acryloxybenzophenone (BPHA) as a hydrogen abstraction type photopolymerization initiator, and 10 mol parts of triethanolamine triacrylate (EtAA3N) as a hydrogen donating monomer A were placed and stirred for 10 minutes to prepare a photocurable composition.

[0088] Examples 2 to 13, Comparative Examples 1 to 14

[0089] A photocurable composition was prepared in the same manner as in Example 1 except that the compounds and blending amounts (parts by mole) were changed to those shown in Table 1. The compounds shown in Table 1 and Table 2 are as follows.

[0090] Basic monomer B

[0091] IBXA: Isobornyl acrylate

[0092] ·BZA: Benzyl acrylate

[0093] ·NOAA: n-octyl acrylate

[0094] Hydrogen abstraction type photopolymerization initiator

[0095] BPHA: 4-Acryloyloxybenzophenone

[0096] ·MeOBPHA: 2-Acryloyloxy-4-methoxybenzophenone

[0097] Hydrogen Donating Monomer A

[0098] ·EtAA3N: triethanolamine triacrylate

[0099] DMA: 2-(Dimethylamino)ethyl acrylate

[0100] DMMA: 2-(dimethylamino)ethyl methacrylate

[0101] ·DEMA: 2-(Diethylamino)ethyl methacrylate

[0102] ·V#200: Cyclic trimethylolpropane formal acrylate

[0103] ·MOMA: Methoxymethyl acrylate

[0104] ·CTFMA: Cyclic trimethylolpropane formal methacrylate

[0105] Hydrogen Donating Monomer X

[0106] ·2MTA: Methoxyethyl acrylate

[0107] ·HEA: 2-Hydroxyethyl Acrylate

[0108] ·AIB: Isobutyl acrylate

[0109] ·HEMA: 2-Hydroxyethyl Methacrylate

[0110] Hydrogen Donating Compound Y

[0111] ·CTFOH: Cyclic trimethylolpropane formal

[0112] [Evaluation and Measurement]

[0113] (Minimum curing radiation dose)

[0114] 0.03 g of each of the prepared photocurable compositions was used, and an illumination of 20 mW / cm 2 The elastic modulus was measured by a rheometer while irradiating with a mercury-xenon lamp, and the starting point of the elastic modulus rise was taken as the minimum curing irradiation dose (mJ / cm 2 ). The results are shown in Tables 1 and 2.

[0115] (Evaluation of yellowing)

[0116] 0.03 g of each of the prepared photocurable compositions was used and the above-mentioned mercury xenon lamp was used to heat the mixture at 15.6 J / cm 2 The photocurable composition was photocured at an irradiation dose of to prepare a cured film. The prepared cured film was visually checked for yellowing. The results are shown in Tables 1 and 2.

[0117] (Evaluation of seepage)

[0118] 5 molar parts of pentaerythritol triacrylate (PETA) as base monomer B, 75 molar parts of cyclic trimethylolpropane formal acrylate (V#200) as hydrogen-donating monomer A, and 20 molar parts of 4-acryloxybenzophenone (BPHA) as hydrogen-abstracting photopolymerization initiator were mixed to prepare a photocurable composition. The prepared photocurable composition was coated on an aluminum plate, and a 20 μm film was formed using a bar coater, and then a high-pressure mercury lamp was used to heat the aluminum plate at 3 J / cm 2 The cured film was made by irradiation with light. The cured film was scraped off and immersed in acetonitrile: water = 90:10 (vol / vol) for 30 minutes. The supernatant after immersion was measured by liquid chromatography to measure the amount of BPHA dissolved. As a result, the amount of BPHA dissolved was 1.8% by mass of the amount added.

[0119] A cured film was prepared by the same method as above except that 20 moles of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO) as a photopolymerization initiator was used instead of 20 moles of 4-acryloxybenzophenone (BPHA) used as a hydrogen abstraction type photopolymerization initiator. The cured film was scraped off and immersed in acetonitrile: water = 90:10 (vol / vol) for 30 minutes. The supernatant after immersion was measured by liquid chromatography to measure the amount of eluted TPO. As a result, the amount of eluted TPO was 14.8% by mass of the added amount.

[0120] These results show that the photopolymerization initiator composition and the photocurable composition of the present invention can effectively suppress the bleeding of the photopolymerization initiator to the surface of the cured film.

[0121] [Table 1]

[0122]

[0123] [Table 2]

[0124]

[0125] As shown in Tables 1 and 2, the photocurable compositions of Examples 1 to 14 can initiate radical polymerization at a lower irradiation dose than the photocurable compositions of Comparative Examples 1 to 14. In addition, it can be seen that yellowing of the cured film can be effectively suppressed by using the hydrogen-donating monomer A having a formal group.

[0126] Industrial Applicability

[0127] The photopolymerization initiator composition of the present invention is useful as a photopolymerization initiator component for use in photocurable compositions (e.g., ultraviolet curable inkjet inks and coatings, etc.), photocurable composition kits (e.g., two-component adhesives and two-component adhesives, etc.), and photocurable resin compositions (e.g., photosensitive resin compositions, resin compositions for hard coats, resin compositions for insulating films, adhesive compositions, and adhesive compositions, etc.).

Claims

1. A photopolymerization initiator composition comprising a hydrogen abstraction type photopolymerization initiator and a monomer A, The hydrogen abstraction type photopolymerization initiator has one or more functional groups containing an ethylenically unsaturated double bond. The monomer A has one or more functional groups containing an ethylenically unsaturated double bond and at least one hydrogen-donating group selected from a formal group, a tertiary amino group, a thioether group and a nitrogen-containing heterocyclic ring.

2. The photopolymerization initiator composition according to claim 1, wherein The hydrogen abstraction type photopolymerization initiator is at least one selected from the group consisting of a benzophenone type photopolymerization initiator, a xanthone type photopolymerization initiator, a thioxanthone type photopolymerization initiator, and an acridone type photopolymerization initiator.

3. The photopolymerization initiator composition according to claim 1, wherein The functional group having an ethylenically unsaturated double bond of the hydrogen abstraction type photopolymerization initiator is a (meth)acryloyloxy group.

4. The photopolymerization initiator composition according to claim 1, wherein The functional group containing an ethylenically unsaturated double bond of the monomer A is a (meth)acryloyl group or a (meth)acryloyloxy group, and the monomer A has a formal group or a tertiary amino group.

5. The photopolymerization initiator composition according to claim 1, wherein The functional group containing an ethylenically unsaturated double bond of the hydrogen abstraction type photopolymerization initiator is an acryloyloxy group, and the functional group containing an ethylenically unsaturated double bond of the monomer A is an acryloyl group or an acryloyloxy group. 6 . A photocurable composition comprising the photopolymerization initiator composition according to claim 1 and a base monomer B.

7. The photocurable composition according to claim 6, wherein The photocurable composition is an ultraviolet curable inkjet ink. 8 . A photocurable composition kit comprising the photopolymerization initiator composition according to claim 1 and a base monomer composition, wherein the base monomer composition contains a base monomer B. 9 . A photocurable resin composition comprising the photopolymerization initiator composition according to claim 1 and a resin component. 10 . A photocurable resin composition comprising the photocurable composition according to claim 6 and a resin component.

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