Method for producing (METH)acrylate resin, method for producing cured product, method for producing insulation material, and method for producing resist member

Abstract

To provide a method for producing a resin material which can obtain a cured product that has excellent photosensitivity, and excellent heat resistance, resistance to thermal yellow discoloration and reflectivity.SOLUTION: A method for producing a (meth)acrylate resin includes a step (i) of separately dropping and mixing a polymerization raw material of a reactive functional group-containing acrylic resin (A1), and a polymerization initiator, and producing the reactive functional group-containing acrylic resin (A1), and a step (ii) of reacting the reactive functional group-containing acrylic resin (A1) with a functional group capable of reacting with the reactive functional group and a polymerizable unsaturated group-containing compound (A2), and producing a (meth)acrylate resin having viscosity which is equal to or less than a predetermined value, wherein the amount of a polymerization inhibitor in the reactive functional group-containing acrylic resin (A1) is equal to or less than a predetermined value, and the reaction of the step (ii) is performed under the atmosphere of gas (b1) containing oxygen and inert gas (b2) in the presence of a basic catalyst with a predetermined range of oxygen concentration while stirring with a predetermined range of unit power.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a (meth)acrylate resin, a method for producing a cured product, a method for producing an insulating material, and a method for producing a resist member. [Background technology]

[0002] When mounting and soldering electronic components on a printed wiring board, solder resist is widely used as a material to prevent solder from adhering to areas other than the mounted area and to form a coating that semi-permanently prevents oxidation and corrosion of wiring. As a technique for forming such solder resist patterns, the photoresist method, which can accurately form fine patterns, is the mainstream, and in particular, due to environmental considerations, the alkaline development type liquid photoresist method is the most popular.

[0003] In addition, printed wiring boards are becoming finer, more multi-layered, and more one-board in order to achieve higher density, and the mounting method is also shifting to surface mount technology (SMT).As a result, there is an increasing demand for solder resist films that are finer, have higher T mass, have higher resolution, higher precision, and are more reliable.

[0004] As a conventional curable resin composition for a solder resist, for example, a curable resin composition containing a modified copolymer obtained by adding an epoxy group-containing unsaturated compound to some acid groups of a copolymer obtained from a (meth)acrylic acid ester and a compound containing an unsaturated group is known (e.g., Patent Document 1). However, the excellent photosensitivity of the curable resin composition and the excellent heat resistance, heat yellowing resistance, and reflectivity of the cured product obtained from the curable resin composition do not satisfy the increasingly high required properties, and are not sufficient for today's market demands.

[0005] Therefore, there has been a demand for a method for efficiently producing a resin material that can give a cured product having excellent photosensitivity, as well as excellent heat resistance, resistance to heat yellowing, and reflectivity. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2003-128725 A Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is to provide a method for efficiently producing a resin material from which a cured product having excellent photosensitivity and excellent heat resistance, resistance to heat yellowing, and reflectivity can be obtained, a method for producing a cured product using the resin material obtained by this method, a method for producing an insulating material, and a method for producing a resist member. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the present inventors have found that the above problems can be solved by producing a (meth)acrylate resin as a polymerizable unsaturated group-containing resin under specific conditions, and have thus completed the present invention.

[0009] That is, the present invention relates to a method for producing a pharmaceutical composition comprising the steps of: (i) producing a reactive functional group-containing acrylic resin (A1) by separately dropping a liquid (L1) containing a polymerization raw material for the reactive functional group-containing acrylic resin (A1) and a liquid (L2) containing a polymerization initiator into an organic solvent and mixing the liquid (L1) to polymerize the polymerization raw material for the acrylic resin (A1); and (ii) a step of reacting the reactive functional group-containing acrylic resin (A1) obtained in the step (i) with a compound (A2) containing a functional group capable of reacting with the reactive functional group and a polymerizable unsaturated group as essential raw materials to produce a (meth)acrylate resin. A method for producing a (meth)acrylate resin, comprising: the amount of the polymerization inhibitor in the reactive functional group-containing acrylic resin (A1) obtained in the step (i) is 500 ppm or less based on the solid content of the acrylic resin (A1); The reaction of step (ii) is carried out in the presence of a basic catalyst under an atmosphere of an oxygen-containing gas (b1) and an inert gas (b2) with stirring; The oxygen concentration in the reaction system in which step (ii) is carried out is in the range of 2 to 12 mass%, The stirring power per unit volume is 0.2 to 8 kW / m 3 This is done as a range of The viscosity of the obtained (meth)acrylate resin at 40°C is 2,000 mPa s or less. The present invention relates to a method for producing a (meth)acrylate resin, a method for producing a cured product using a resin material obtained by this method, a method for producing an insulating material, and a method for producing a resist member.

[0010] Suitable embodiments of the present invention include the following [1] to [8]. [1] The following steps: (i) producing a reactive functional group-containing acrylic resin (A1) by separately dropping a liquid (L1) containing a polymerization raw material for the reactive functional group-containing acrylic resin (A1) and a liquid (L2) containing a polymerization initiator into an organic solvent and mixing the liquid (L1) to polymerize the polymerization raw material for the acrylic resin (A1); and (ii) a step of reacting the reactive functional group-containing acrylic resin (A1) obtained in the step (i) with a compound (A2) containing a functional group capable of reacting with the reactive functional group and a polymerizable unsaturated group as essential raw materials to produce a (meth)acrylate resin. A method for producing a (meth)acrylate resin, comprising: the amount of the polymerization inhibitor in the reactive functional group-containing acrylic resin (A1) obtained in the step (i) is 500 ppm or less based on the solid content of the acrylic resin (A1); The reaction of step (ii) is carried out in the presence of a basic catalyst under an atmosphere of an oxygen-containing gas (b1) and an inert gas (b2) with stirring; The oxygen concentration in the reaction system in which step (ii) is carried out is in the range of 2 to 12 mass%, The stirring power per unit volume is 0.2 to 8 kW / m 3 This is done as a range of The viscosity of the obtained (meth)acrylate resin at 40°C is 2,000 mPa s or less. A method for producing a (meth)acrylate resin. [2] The method for producing a (meth)acrylate resin according to the above [1], wherein the acrylic resin (A1) is an epoxy group- or carboxyl group-containing acrylic resin, and the compound (A2) is an unsaturated monobasic acid or an epoxy group-containing (meth)acrylate. [3] The method for producing a (meth)acrylate resin according to the above [2], wherein the acrylic resin (A1) is an epoxy group-containing acrylic resin, and the compound (A2) is an unsaturated monobasic acid. [4] The method for producing a (meth)acrylate resin according to the above [2], wherein the acrylic resin (A1) is a carboxyl group-containing acrylic resin, and the compound (A2) is an epoxy group-containing (meth)acrylate. [5] A method for producing a curable resin composition, comprising a step of mixing a (meth)acrylate resin obtained by the method for producing a (meth)acrylate resin according to any one of the above [1] to [4] with a photopolymerization initiator to obtain a curable resin composition. [6] A method for producing a cured product, comprising the step of curing the curable resin composition obtained by the method for producing a curable resin composition described in [5] above to obtain a cured product. [7] A method for producing an insulating material, comprising using a cured product obtained by the method according to [6] above. [8] A method for producing a resist member, comprising using a cured product obtained by the method according to [6] above. Effect of the Invention

[0011] According to the present invention, it is possible to obtain a (meth)acrylate resin which is a resin material capable of giving a cured product having excellent photosensitivity and excellent heat resistance, resistance to heat yellowing, and reflectivity, and a cured product, an insulating material, and a resist member using such a resin material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below.

[0013] (term) In this specification, the term "(meth)acrylate resin" refers to a resin having an acryloyl group, a methacryloyl group, or both in the molecule. In addition, the term "(meth)acryloyl group" refers to either or both of an acryloyl group and a methacryloyl group, and the term "(meth)acrylate" is a general term for acrylate and methacrylate. In this specification, "ppm" is based on mass. In this specification, the term "polymerizable unsaturated group" refers to a functional group contained in a resin that cures the resin when exposed to light (eg, ultraviolet light). The "polymerizable unsaturated group" includes, for example, a group containing a carbon-carbon double bond, such as a vinylidene structure (H 2 C<)-containing groups (e.g., (meth)acryloyl group, acrylamide group, isopropenyl group, vinyl ether group, etc.), vinyl group, allyl group, 1-propenyl group, styryl group, styrylmethyl group, maleimide group, etc.

[0014] (Method for producing (meth)acrylate resin) The method of the present invention comprises the steps of: (i) a step of separately dropping a liquid (L1) (hereinafter sometimes abbreviated as "liquid (L1)") containing a polymerization raw material for a reactive functional group-containing acrylic resin (A1) (hereinafter sometimes abbreviated as "acrylic resin (A1)") and a liquid (L2) (hereinafter sometimes abbreviated as "liquid (L2)") containing a polymerization initiator into an organic solvent and mixing them to polymerize the polymerization raw material for the acrylic resin (A1), thereby producing a reactive functional group-containing acrylic resin (A1); and (ii) a step of producing a (meth)acrylate resin by reacting the reactive functional group-containing acrylic resin (A1) obtained in the step (i) with a compound (A2) (hereinafter sometimes abbreviated as "compound (A2)") containing a functional group capable of reacting with the reactive functional group and a polymerizable unsaturated group as an essential raw material. A method for producing a (meth)acrylate resin, comprising: the amount of the polymerization inhibitor in the reactive functional group-containing acrylic resin (A1) obtained in the step (i) is 500 ppm or less based on the solid content of the acrylic resin (A1); The reaction of step (ii) is carried out in the presence of a basic catalyst under an atmosphere of an oxygen-containing gas (b1) and an inert gas (b2) with stirring; The oxygen concentration in the reaction system in which step (ii) is carried out is in the range of 2 to 12 mass%, The stirring power per unit volume is 0.2 to 8 kW / m 3 This is done as a range of The viscosity of the obtained (meth)acrylate resin at 40°C is 2,000 mPa s or less. A method for producing a (meth)acrylate resin The (meth)acrylate resin obtained by the method of the present invention has chemical properties as a polymerizable unsaturated group-containing resin.

[0015] That is, the method of the present invention comprises at least two steps: a step (step (i)) of polymerizing the polymerization raw material of the reactive functional group-containing acrylic resin (A1) to produce the reactive functional group-containing acrylic resin (A1), and a step (step (ii)) of modifying the acrylic resin (A1) obtained in the step (i) to produce a (meth)acrylate resin as a polymerizable unsaturated group-containing resin. Then, by carrying out the steps (i) and (ii) under specific conditions, particularly by separately dropping and mixing the polymerization raw material of the acrylic resin (A1) and the polymerization initiator in the step (i), and by setting the oxygen concentration in the reaction system, the unit power during stirring, and the viscosity of the obtained (meth)acrylate resin within a predetermined range in the step (ii), it is possible to obtain a (meth)acrylate resin that is a resin material having excellent photosensitivity in the curable resin composition, and excellent heat resistance, heat yellowing resistance, and reflectivity in the cured product obtained from the curable resin composition.

[0016] The method of the present invention may also optionally include: Step (iii): A step of reacting the (meth)acrylate resin obtained in step (ii) with a polybasic acid anhydride (C) as a raw material to form an acid group in the (meth)acrylate resin (hereinafter referred to as the "acid group forming step"). It may further include.

[0017] In a specific embodiment, the "reactive functional group" is an "epoxy group or a carboxyl group" (i.e., the acrylic resin (A1) is an epoxy group- or carboxyl group-containing acrylic resin), and the "compound (A2) containing a functional group capable of reacting with the reactive functional group and a polymerizable unsaturated group" is an "unsaturated monobasic acid or epoxy group-containing (meth)acrylate".

[0018] In a further embodiment, the acrylic resin (A1) is an epoxy group-containing acrylic resin, and the compound (A2) is an unsaturated monobasic acid.

[0019] In another further embodiment, the acrylic resin (A1) is a carboxyl group-containing acrylic resin, and the compound (A2) is an epoxy group-containing (meth)acrylate.

[0020] (Step (i): Polymerization step) In step (i), the liquid (L1) and the liquid (L2) are separately dropped into an organic solvent, mixed, and the polymerization raw material of the acrylic resin (A1) is polymerized to produce the reactive functional group-containing acrylic resin (A1). In step (i), the polymerization raw material of the acrylic resin (A1) is polymerized to produce the reactive functional group-containing acrylic resin (A1).

[0021] <Reactive Functional Group-Containing Acrylic Resin (A1)> The "reactive functional group-containing acrylic resin (A1)" is an acrylic resin containing a "reactive functional group", which is capable of forming a polymerizable unsaturated group on the acrylic resin (A1) by reacting with a compound (A2) (i.e., a "compound (A2) containing a functional group and a polymerizable unsaturated group capable of reacting with a reactive functional group"). Examples of the reactive functional group include an epoxy group and a carboxyl group. Examples of the reactive functional group-containing acrylic resin (A1) include an epoxy group- or carboxyl group-containing acrylic resin. Hereinafter, the polymerization raw material of the reactive functional group-containing acrylic resin (A1) will be described taking the case where the reactive functional group-containing acrylic resin (A1) is an epoxy group- or carboxyl group-containing acrylic resin as an example.

[0022] <Polymerization raw materials for reactive functional group-containing acrylic resin (A1)> The polymerization raw materials for the reactive functional group-containing acrylic resin (A1) include (meth)acrylic monomers and monomers other than (meth)acrylic monomers (hereinafter referred to as "other monomers"). The (meth)acrylic monomers include epoxy group-containing (meth)acrylic monomers, carboxyl group-containing (meth)acrylic monomers, and (meth)acrylic monomers other than epoxy group-containing (meth)acrylic monomers and carboxyl group-containing (meth)acrylic monomers (hereinafter referred to as "other (meth)acrylic monomers"). The polymerization raw materials for the acrylic resin (A1) may be the above-mentioned monomers alone or may be a mixture of one or more of the above-mentioned monomers. The types, combinations, and blending ratios of the polymerization raw materials for the acrylic resin (A1) are appropriately selected depending on the types, combinations, and content ratios of the reactive functional groups (epoxy groups, carboxyl groups) contained in the resulting acrylic resin (A1). When the acrylic resin (A1) is an acrylic resin containing an epoxy group, the acrylic resin (A1) is a polymer containing a repeating unit derived from an epoxy group-containing (meth)acrylic monomer.When the acrylic resin (A1) is an acrylic resin containing a carboxyl group, the acrylic resin (A1) is a polymer containing a repeating unit derived from a carboxyl group-containing (meth)acrylic monomer.

[0023] <Polymerization raw material for acrylic resin (A1): epoxy group-containing (meth)acrylic monomer> The above-mentioned "epoxy group-containing (meth)acrylic monomer" may, for example, be an epoxy group-containing (meth)acrylate. The "epoxy group-containing (meth)acrylate" refers to a compound containing an epoxy group and a (meth)acryloyl group in one molecule. The epoxy group-containing (meth)acrylate may, for example, be a glycidyl group-containing (meth)acrylate monomer such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, or 3,4-epoxycyclohexylmethyl (meth)acrylate; or a mono(meth)acrylate of a diglycidyl ether compound such as dihydroxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether, biphenol diglycidyl ether, or bisphenol diglycidyl ether. Glycidyl group-containing (meth)acrylate monomers (eg, glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, 3,4-epoxycyclohexylmethyl (meth)acrylate, etc.) are preferred, and glycidyl (meth)acrylate is more preferred.

[0024] <Polymerization raw material for acrylic resin (A1): Carboxyl group-containing (meth)acrylic monomer> The above-mentioned "carboxyl group-containing (meth)acrylic monomer" is not particularly limited, but examples thereof include unsaturated monocarboxylic acids, carboxyl group-containing monofunctional or polyfunctional (meth)acrylates, and compounds represented by structural formula (1) described below.

[0025] Examples of unsaturated monocarboxylic acids include (meth)acrylic acid (acrylic acid, methacrylic acid), ((meth)acryloyloxy)acetic acid, 2-carboxyethyl (meth)acrylate, 3-carboxypropyl (meth)acrylate, 1-[2-((meth)acryloyloxy)ethyl] succinate, 1-(2-(meth)acryloyloxyethyl) phthalate, 2-((meth)acryloyloxy)ethyl hydrogen hexahydrophthalate, crotonic acid, cinnamic acid, α-cyanocinnamic acid, β-styrylacrylic acid, β-furfurylacrylic acid, and lactone-modified products, esterified products, and acid halides thereof.

[0026] Examples of the carboxyl group-containing monofunctional or polyfunctional (meth)acrylate include carboxyl group-containing monofunctional or polyfunctional (meth)acrylate obtained by reacting a polybasic acid or polybasic acid anhydride with a hydroxyl group-containing monofunctional or polyfunctional (meth)acrylate. Examples of the polybasic acid include saturated dicarboxylic acids (e.g., oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid), unsaturated dicarboxylic acids (e.g., maleic acid, fumaric acid, etc.), aromatic dicarboxylic acids (e.g., phthalic acid, isophthalic acid, terephthalic acid), etc. Examples of the polybasic acid anhydrides include succinic anhydride, maleic anhydride, phthalic anhydride, etc. Examples of the hydroxyl group-containing monofunctional or polyfunctional (meth)acrylate include pentaerythritol triacrylate, dipentaerythritol pentaacrylate, etc.

[0027] As the (meth)acrylate compound having a carboxyl group, a compound represented by the following structural formula (1) can also be used.

[0028] [ka] [In formula (1), X represents an alkylene chain having 1 to 10 carbon atoms, a polyoxyalkylene chain, a (poly)ester chain, an aromatic hydrocarbon chain, or a (poly)carbonate chain, and may have a halogen atom, an alkoxy group, or the like in the structure. Y represents a hydrogen atom or a methyl group.]

[0029] Examples of the alkylene chain having 1 to 10 carbon atoms include linear alkylene chains such as methylene chains, ethylene chains, propylene chains, butylene chains, pentylene chains, hexylene chains, heptylene chains, octylene chains, nonylene chains, and decylene chains; branched alkylene chains such as a methylmethylene chain, an ethylmethylene chain, a methylethylene chain, an ethylethylene chain, a methylpropylene chain, a methylbutylene chain, and a methylpentylene chain; Alicyclic structure-containing alkylene chains such as cyclopropylene chains, cyclobutylene chains, cyclopentylene chains, cyclohexylene chains, and methylcyclohexylene chains etc.

[0030] Examples of the polyoxyalkylene chain include a polyoxyethylene chain and a polyoxypropylene chain.

[0031] An example of the (poly)ester chain is a (poly)ester chain represented by the following formula (X-1).

[0032] [ka] [In formula (X-1), R 1 is an alkylene group having 1 to 10 carbon atoms, and n is an integer of 1 to 5.

[0033] Examples of the aromatic hydrocarbon chain include a phenylene chain, a naphthylene chain, a biphenylene chain, a phenylnaphthylene chain, a binaphthylene chain, etc. In addition, a hydrocarbon chain having an aromatic ring such as a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring as a partial structure can also be used.

[0034] An example of the (poly)carbonate chain is a (poly)carbonate chain represented by the following formula (X-2).

[0035] [ka] [In formula (X-2), R 2 is an alkylene group having 1 to 10 carbon atoms, and n is an integer of 1 to 5.

[0036] Further, as the (meth)acrylate compound having a carboxyl group, for example, a compound represented by the following general formula (X-3) can also be used. [ka] (In the above general formula (X-3), X 4 represents an alkylene chain having 1 to 10 carbon atoms, a polyoxyalkylene chain, a (poly)ester chain, an aromatic hydrocarbon chain, or a (poly)carbonate chain, and may contain a halogen atom, an alkoxy group, or the like in the structure. Y 4 is a hydrogen atom or a methyl group. 4 is an integer between 1 and 5.)

[0037] These (meth)acrylate compounds having a carboxyl group can be used alone or in combination of two or more. Among these, acrylic acid, methacrylic acid, and ω-carboxy-polycaprolactone mono(meth)acrylate are preferred because they tend to give an acid group- and polymerizable unsaturated group-containing resin capable of forming a cured product excellent in photosensitivity, elongation, heat yellowing resistance, and adhesion.

[0038] <Polymerization raw material for acrylic resin (A1): Other (meth)acrylic monomers> Examples of the above-mentioned "other (meth)acrylic monomers" include aliphatic mono(meth)acrylate compounds such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, pentyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and octyl(meth)acrylate; and alicyclic mono(meth)acrylates such as cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, and adamantyl mono(meth)acrylate. compounds; heterocyclic mono(meth)acrylate compounds such as tetrahydrofurfuryl acrylate; mono(meth)acrylate compounds such as aromatic mono(meth)acrylate compounds such as benzyl(meth)acrylate, phenyl(meth)acrylate, phenylbenzyl(meth)acrylate, phenoxy(meth)acrylate, phenoxyethyl(meth)acrylate, phenoxyethoxyethyl(meth)acrylate, phenoxybenzyl(meth)acrylate, and phenylphenoxyethyl(meth)acrylate; (Poly)oxyalkylene-modified mono(meth)acrylate compounds in which a polyoxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain has been introduced into the molecular structure of a acrylate monomer; lactone-modified mono(meth)acrylate compounds in which a (poly)lactone structure has been introduced into the molecular structure of the above-mentioned various mono(meth)acrylate compounds; ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, aliphatic di(meth)acrylate compounds such as 1,4-cyclohexanedimethanol di(meth)acrylate, norbornane di(meth)acrylate, norbornane dimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, etc.; aromatic di(meth)acrylate compounds such as biphenol di(meth)acrylate, bisphenol di(meth)acrylate, etc.;Polyoxyalkylene-modified di(meth)acrylate compounds in which a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain has been introduced into the molecular structure of the various di(meth)acrylate compounds described above; lactone-modified di(meth)acrylate compounds in which a (poly)lactone structure has been introduced into the molecular structure of the various di(meth)acrylate compounds described above; aliphatic tri(meth)acrylate compounds such as trimethylolpropane tri(meth)acrylate and glycerin tri(meth)acrylate; (poly)oxyalkylene-modified tri(meth)acrylate compounds in which a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain has been introduced into the molecular structure of the aliphatic tri(meth)acrylate compounds described above; lactone-modified tri(meth)acrylate compounds having a (poly)lactone structure introduced into the molecular structure of the aliphatic tri(meth)acrylate compounds; tetrafunctional or higher aliphatic poly(meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate; tetrafunctional or higher (poly)oxyalkylene-modified poly(meth)acrylate compounds having a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, a (poly)oxytetramethylene chain, etc. introduced into the molecular structure of the aliphatic poly(meth)acrylate compounds; tetrafunctional or higher lactone-modified poly(meth)acrylate compounds having a (poly)lactone structure introduced into the molecular structure of the aliphatic poly(meth)acrylate compounds;(Meth)acrylate compounds containing a reactive functional group other than the reactive functional group contained in the acrylic resin (A1) (for example, when the acrylic resin (A1) is an epoxy group- or carboxyl group-containing acrylic resin, such (meth)acrylate compounds include (meth)acrylate compounds containing a reactive functional group other than an epoxy group or a carboxyl group, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, trimethylolpropane (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol (meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol (meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol di ... Hydroxyl group-containing (meth)acrylate compounds such as erythritol (meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane (meth)acrylate, ditrimethylolpropane di(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate; isocyanate group-containing (meth)acrylate compounds such as 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and 1,1-bis(acryloyloxymethyl)ethyl isocyanate.);

[0039] <Polymerization raw materials for acrylic resin (A1): Other monomers> As the above-mentioned "other monomer", for example, an unsaturated group-containing compound can be used. Examples of the unsaturated group-containing compound include an acrylamide group-containing compound, a vinyl group-containing compound, an allyl group-containing compound, an unsaturated group-containing acid anhydride, and an unsaturated group-containing acid imide compound. Examples of the acrylamide group-containing compound include N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-methoxyethyl(meth)acrylamide, N-ethoxyethyl(meth)acrylamide, and N-butoxyethyl(meth)acrylamide. Examples of the vinyl group-containing compound include styrene, methylstyrene, tert-butylstyrene, methoxystyrene (e.g., vinylanisole), ethoxystyrene, acetoxystyrene, vinylnaphthalene, and divinylbenzene. Examples of the allyl group-containing compound include allyl alcohol, allyl acetate, diallyl ether, allyl benzene, allyl methyl benzene, allyl phenol, allyl methoxybenzene (e.g., allyl anisole), allyl methoxyphenol (e.g., eugenol), allyl dimethoxybenzene (e.g., methyl eugenol), allyl dimethoxyphenol, allyl phenyl ether, and diallyl bisphenol A. Examples of the unsaturated group-containing acid anhydride include maleic anhydride. Examples of the unsaturated group-containing acid imide compound include maleimide.

[0040] <Polymerization inhibitor / amount of polymerization inhibitor in step (i)> If no polymerization inhibitor is present in the polymerization raw material of the acrylic resin (A1), the polymerization raw material of the acrylic resin (A1) is likely to undergo a polymerization reaction and undergo deterioration such as gelation at a stage before the start of step (i) (e.g., during storage of the polymerization raw material). In order to prevent such deterioration such as gelation of the polymerization raw material of the acrylic resin (A1), it is preferable that the polymerization raw material of the acrylic resin (A1) contains a minimum amount of polymerization inhibitor capable of preventing gelation. On the other hand, if the amount of polymerization inhibitor in the polymerization raw material of the acrylic resin (A1) is too large, the polymerization reaction is inhibited and a sufficient degree of polymerization is not obtained, and a (meth)acrylate resin that is a resin material capable of obtaining a cured product having excellent photosensitivity, excellent heat resistance, heat yellowing resistance, and reflectivity cannot be obtained. From the viewpoint of preventing this, it is preferable that the amount of polymerization inhibitor contained in the polymerization raw material of the acrylic resin (A1) is not excessive. In order to make the amount of polymerization inhibitor contained in the polymerization raw materials for the acrylic resin (A1) the minimum necessary and not excessive, the amount of the polymerization inhibitor in the polymerization raw materials for the acrylic resin (A1) is, relative to the total amount of solids in the raw materials, 500 ppm or less, preferably 400 ppm or less, more preferably 300 ppm or less, and even more preferably 250 ppm or less, and is preferably 1 ppm or more, more preferably 5 ppm or more, and even more preferably 10 ppm or more. The amount of the polymerization inhibitor in each of the polymerization raw materials for the acrylic resin (A1) is the minimum necessary and not excessive, and therefore the amount relative to the solid content of each of the polymerization raw materials may be 500 ppm or less, preferably 400 ppm or less, more preferably 300 ppm or less, and even more preferably 250 ppm or less, and is preferably 1 ppm or more, more preferably 5 ppm or more, and even more preferably 10 ppm or more. Furthermore, the amount of the polymerization inhibitor in the liquid (L2) used in the step (i) is the minimum necessary and not an excessive amount, and therefore the amount relative to the total amount of solids in the raw materials may be 500 ppm or less, preferably 400 ppm or less, more preferably 300 ppm or less, even more preferably 200 ppm or less, even more preferably 100 ppm or less, more preferably 50 ppm or less, preferably 0 ppm or more, more preferably 1 ppm or more, and more preferably 5 ppm or more. Furthermore, the amount of the polymerization inhibitor in the reactive functional group-containing acrylic resin (A1) obtained in step (i) is, by setting the amount of the polymerization inhibitor to the minimum necessary and not excessive amount in step (i), 500 ppm or less, preferably 400 ppm or less, more preferably 300 ppm or less, even more preferably 250 ppm or less, and even more preferably 200 ppm or less, and is preferably 1 ppm or more, more preferably 5 ppm or more, and even more preferably 10 ppm or more, relative to the solid content of the acrylic resin (A1).

[0041] Examples of the polymerization inhibitor include p-methoxyphenol, p-methoxycresol, dibutylhydroxytoluene, 4-methoxy-1-naphthol, 4,4'-dialkoxy-2,2'-bi-1-naphthol, 3-(N-salicyloyl)amino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecane dihydrazide, styrenated phenol, N-isopropyl-N'-phenylbenzene-1,4-diamine, 6-ethoxy-2,2,4 -Trimethyl-1,2-dihydroquinoline and other phenolic compounds, hydroquinone, methylhydroquinone, p-benzoquinone, methyl-p-benzoquinone, 2,5-diphenylbenzoquinone, 2-hydroxy-1,4-naphthoquinone, anthraquinone, diphenoquinone and other quinone compounds, melamine, p-phenylenediamine, 4-aminodiphenylamine, N,N'-diphenyl-p-phenylenediamine, Ni-propyl-N'-phenyl-p-phenylenediamine, N-(1.amine compounds such as 3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, diphenylamine, 4,4'-dicumyl-diphenylamine, 4,4'-dioctyl-diphenylamine, poly(2,2,4-trimethyl-1,2-dihydroquinoline), styrenated diphenylamine, reaction products of styrenated diphenylamine and 2,4,4-trimethylpentene, reaction products of diphenylamine and 2,4,4-trimethylpentene, phenothiazine, distearyl thiodipropionate, 2,2-bis({[3-(dodecyl) thioether compounds such as N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, p-nitrosophenol, nitrosobenzene, p-nitrosodiphenylamine, α-nitroso-β-naphthol, N,N-dimethyl-p-nitrosoaniline, p-nitrosodiphenylamine, p-nitrosodimethylamine, p-nitrosophenyl ... N-nitroso-N,N-diethylamine, N-nitrosoethanolamine, N-nitrosodi-n-butylamine, N-nitroso-Nn-butyl-4-butanolamine, N-nitroso-diisopropanolamine, N-nitroso-N-ethyl-4-butanolamine, 5-nitroso-8-hydroxyquinoline, N-nitrosomorpholine, N-nitroso-N-phenylhydroxylamine ammonium salt, N-nitrosobenzene, N-nitroso-N-methyl-p-toluenesulfonamide, N-nitroso-N-ethylurethane, N-nitroso-Nn -Propyl urethane, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, sodium 1-nitroso-2-naphthol-3,6-sulfonate, sodium 2-nitroso-1-naphthol-4-sulfonate, 2-nitroso-5-methylaminophenol hydrochloride, 2-nitroso-5-methylaminophenol hydrochloride and other nitroso compounds, esters of phosphoric acid and octadecane-1-ol, triphenyl phosphite, 3,9-dioctadecan-1-yl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]Undecane, trisnonylphenyl phosphite, phosphorous acid-(1-methylethylidene)-di-4,1-phenylenetetra-C12-15-alkyl ester, 2-ethylhexyl diphenyl phosphite, diphenyl isodecyl phosphite, triisodecyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite and other phosphite compounds, bis(dimethyldithiocarbamato-κ(2)S,S')zinc, diethyldithiocarbamate , zinc compounds such as zinc dibutyl dithiocarbamate, nickel compounds such as bis(N,N-dibutylcarbamodithioato-S,S')nickel, and sulfur compounds such as 1,3-dihydro-2H-benzimidazole-2-thione, 4,6-bis(octylthiomethyl)-o-cresol, 2-methyl-4,6-bis[(octan-1-ylsulfanyl)methyl]phenol, dilauryl thiodipropionate, and distearyl 3,3'-thiodipropionate.

[0042] <Polymerization initiator / amount of polymerization initiator in step (i)> Examples of the polymerization initiator include radical polymerization initiators, etc. Examples of the radical polymerization initiator include organic peroxides, azo initiators, benzaldehyde structure-containing compound-based initiators, phosphorus-based initiators, sulfur-based initiators, hydrogen peroxide, and persulfates.

[0043] Examples of organic peroxides include: Ketone peroxide compounds such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide, and methylcyclohexanone peroxide; peroxyketal compounds such as 1,1-bis(tert-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-hexylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)-2-methylcyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, 4,4-bis(tert-butylperoxy)butyl pentanoate, and 1,1-di(tert-hexylperoxy)cyclohexane; Hydroperoxide compounds such as 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, tert-butyl hydroperoxide, p-menthane hydroperoxide, and diisopropylbenzene hydroperoxide; dialkyl peroxide compounds such as dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,3-bis(tert-butylperoxyisopropyl)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3; diacyl peroxide compounds such as diisobutyryl peroxide, bis-3,5,5-trimethylhexanol peroxide, dilauroyl peroxide, dibenzoyl peroxide, m-toluylbenzoyl peroxide, and succinic acid peroxide; 1,1,3,3-tetramethylbutyl peroxy neodecanoate, α-cumyl peroxy neodecanoate, tert-butyl peroxy neodecanoate, tert-hexyl peroxy neodecanoate, tert-butyl peroxy neoheptanoate, tert(hexyl peroxy pivalate, tert-butyl peroxy pivalate, 1,1,3,3-tetramethylbutyl peroxy 2-ethylhexanoate, tert-amyl peroxy 2-ethylhexanoate, tert-butyl peroxy 2-ethylhexanoate, tert-butyl peroxy isobutyrate, di-tert-butyl peroxy hexahydroterephthalate, 1,1,3,3-tetramethylbutyl peroxy 3,5,5-trimethylhexanate, tert-amyl peroxy 3,5,5-trimethylhexanoate, tert-butyl peroxy -Peroxyester compounds such as 3,5,5-trimethylhexanoate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, dibutyl peroxytrimethyladipate, di-tert-butyl peroxide, (2-ethylhexanoyl)(tert-butyl)peroxide, 2,5-dimethyl-2,5-di-2-ethylhexanoylperoxyhexane, tert-hexylperoxy-2-ethylhexanoate, tert-hexylperoxyisopropyl monocarbonate, tert-butyl peroxylaurate, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-di-benzoylperoxyhexane, tert-hexylperoxybenzoate, and tert-hexylperoxyacetate. etc.

[0044] Examples of the azo initiator include 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis(2-(2-imidazolin-2-yl)propane) dihydrochloride, 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2'-azobis(N-(2-propenyl)-2-methylpropionamide), 2,2'-azobis(N-butyl-2-methylpropionamide), azobisisobutyronitrile, and 2,2'-azobis(2-methylbutyronitrile).

[0045] The benzaldehyde structure-containing compound initiator refers to a compound that contains a benzaldehyde structure and has activity as an initiator. The "benzaldehyde structure-containing compound" refers to a compound represented by the following structural formula (B-1). [ka] [In structural formula (B-1), E 1 is a hydrogen atom or any substituent, E 2 , E 3 , E 4 , E 5 , and E 6 are each independently a hydrogen atom or any substituent, or 2 , E 3 , E 4 , E 5 , and E 6 Two or more of these together form a ring structure, and E 2 , E 3 , E 4 , E 5 , and E 6 The remainder is a hydrogen atom or an arbitrary substituent. E 1 , E 2 , E 3 , E 4 , E 5 , and E 6The optional substituents which may be taken by the group are not particularly limited, and examples thereof include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, pentoxy, and hexyloxy; alkylthio groups such as methylthio, ethylthio, propylthio, butylthio, pentylthio, and hexylthio; hydroxy groups; aromatic ring-containing groups such as phenyl, phenoxy, and benzyl; heterocyclic groups such as morpholino; and alkyl groups, cycloalkyl groups, alkoxy groups, alkylthio groups, hydroxy groups, aromatic ring-containing groups, and heterocyclic groups in which hydrogen atoms are substituted with these substituents. Examples of benzaldehyde structure-containing compound initiators (i.e., compounds represented by the above structural formula (B-1)) include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin ethyl ether, benzophenone, and methylbenzophenone.

[0046] Examples of phosphorus-based initiators include acylphosphine oxides, etc. Examples of sulfur-based initiators include thioxanthone, etc.

[0047] These polymerization initiators can be used alone or in combination of two or more. When a radical polymerization initiator is used as the polymerization initiator, the radical polymerization initiator may be used as a redox polymerization initiator in combination with a reducing agent such as ascorbic acid.

[0048] The amount of the polymerization initiator used may be an amount that allows the polymerization to proceed smoothly, and is preferably in the range of 0.1 to 20 parts by mass, and more preferably in the range of 0.5 to 10 parts by mass, per 100 parts by mass of the total of the polymerization raw materials for the acrylic resin (A1).

[0049] <Organic solvent> The organic solvent is used in step (i) to drop the liquid (L1) and the liquid (L2) and carry out a polymerization reaction of the polymerization raw materials of the acrylic resin (A1) in the liquid. The amount of such an organic solvent used is preferably in the range of 30 to 300 parts by mass, more preferably in the range of 40 to 200 parts by mass, per 100 parts by mass of the total of the polymerization raw materials (monomers used in polymerization) used in the polymerization reaction.

[0050] Examples of organic solvents include ketone solvents such as methyl ethyl ketone, acetone, dimethylformamide, and methyl isobutyl ketone; cyclic ether solvents such as tetrahydrofuran and dioxolane; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; aromatic solvents such as toluene, xylene, and solvent naphtha; alicyclic solvents such as cyclohexane and methylcyclohexane; alcohol solvents such as carbitol, cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether; glycol ether solvents such as alkylene glycol monoalkyl ether, dialkylene glycol monoalkyl ether (e.g., dipropylene glycol monoethyl ether), and dialkylene glycol monoalkyl ether acetate; methoxypropanol, cyclohexanone, methyl cellosolve, diethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate. These organic solvents can be used alone or in combination of two or more.

[0051] <Dropping in step (i)> In step (i), the liquid (L1) and the liquid (L2) are dropped separately into an organic solvent and mixed. By dropping the liquid (L1) and the liquid (L2) separately, mixing them, and reacting them, it is possible to obtain a (meth)acrylate resin that is a resin material capable of obtaining a cured product having excellent photosensitivity, heat resistance, heat yellowing resistance, and reflectivity.

[0052] <Liquid (L1) used for dropping in step (i)> As the liquid (L1), for example, a single liquid may be used, or a combination of multiple liquids may be used. The liquid (L1) usually further contains an organic solvent. The organic solvents exemplified above can be used as the organic solvent that the liquid (L1) may contain. However, when the polymerization raw material of the acrylic resin (A1) is liquid, the liquid (L1) may or may not contain an organic solvent. Even in this case, it is preferable that the liquid (L1) contains an organic solvent from the viewpoint of facilitating the adjustment of the dropping amount. When the liquid (L1) contains an organic solvent, the content of the organic solvent is preferably in the range of 10 to 200 parts by mass, more preferably in the range of 20 to 150 parts by mass, relative to 100 parts by mass of the polymerization raw material.

[0053] <Liquid (L2) used for dropping in step (i)> The liquid (L2) usually further contains an organic solvent. The organic solvents exemplified above can be used as the organic solvent that the liquid (L2) can contain, and it is preferable to use the same type of organic solvent as the organic solvent into which the liquid (L1) and the liquid (L2) are dropped. However, when the polymerization initiator is a liquid, the liquid (L2) may or may not contain an organic solvent. Even in this case, it is preferable that the liquid (L2) contains an organic solvent from the viewpoint of facilitating the adjustment of the dropping amount. When the liquid (L2) contains an organic solvent, the content of the organic solvent is preferably in the range of 0.1 to 10 parts by mass, more preferably in the range of 0.5 to 5 parts by mass, per part by mass of the polymerization initiator.

[0054] <Conditions for Dropping in Step (i)> The liquid (L1) and the liquid (L2) are preferably adjusted in temperature (e.g., cooled, kept warm) to a temperature at which the polymerization reaction does not proceed much from the time when the liquid (L1) and the liquid (L2) are prepared until the liquid (L1) and the liquid (L2) are held in a dropping container (e.g., a dropping funnel) and dropped and removed from the dropping container. Such a temperature is preferably 40° C. or lower, more preferably 35° C. or lower, and is preferably 0° C. or higher, and more preferably 10° C. or higher. The reaction liquid is preferably adjusted (e.g., heated or kept warm) to a temperature suitable for the polymerization reaction at the start, during, and after the dropwise addition of the liquid (L1) and the liquid (L2). The temperature suitable for the polymerization reaction is preferably in the range of 60 to 180°C, more preferably in the range of 70 to 150°C.

[0055] The timing of dropping the liquid (L1) and the liquid (L2) may be simultaneous or may be shifted. When the timing of dropping is shifted, one of the liquids may be dropped preferentially and then the other liquid may be dropped, or the liquids may be dropped alternately. When dropping the liquids at shifted times, the interval between drops may be, for example, about 0.5 to 2 hours. In addition, both liquids may be dropped at the same place on the liquid surface of the organic solvent, or may be dropped at different places, but when dropping them at the same time, it is preferable to drop them at different places. The total time required for dropping is preferably in the range of 0.5 to 10 hours, more preferably in the range of 1 to 5 hours.

[0056] <Reaction atmosphere in step (i)> The atmosphere in which the reaction in step (i) is carried out is not particularly limited as long as it is an atmosphere that suppresses the influence on the reaction, and it is preferable to carry out the reaction in an inert gas atmosphere. Examples of the inert gas include those exemplified as "inert gas (b2)" in step (ii) described later.

[0057] <Mixing in step (i)> The reaction in step (i) may be carried out with stirring. The stirring is performed with a stirring power per unit volume of 0.2 to 8 kW / m 3 The range is preferably 0.5 to 6 kW / m 3 More preferably, the range is 1 to 5 kW / m 3 By setting the unit power during stirring within the above range, the uniformity of the reaction liquid is increased, and as a result, a (meth)acrylate resin can be obtained that serves as a resin material capable of producing a cured product having excellent photosensitivity, and excellent heat resistance, heat yellowing resistance, and reflectivity.

[0058] <Adjustment of the progress of the polymerization reaction in step (i)> After the dropping of the liquid (L1) and the liquid (L2) is completed, a small amount of the liquid (L2) may be dropped again to react all the remaining polymerizable unsaturated groups, and then the reaction liquid may be held for a predetermined time at a temperature suitable for the polymerization reaction. When the liquid (L2) is dropped again, the amount of the polymerization initiator in the liquid (L2) to be dropped is preferably 0.1 to 5 parts by mass relative to the total amount of the polymerization monomers (solid content). In addition, the amount of the solvent in the liquid (L2) to be dropped is preferably 0.1 to 10 times the amount of the polymerization initiator by mass.

[0059] In another embodiment, after the dropwise addition of the liquid (L1) and the liquid (L2) is completed, the reaction liquid may be held at a temperature suitable for the polymerization reaction for a predetermined time in order to sufficiently proceed with the polymerization reaction and to sufficiently deactivate any remaining peroxide.

[0060] The temperature at which the reaction solution is held can be selected from the viewpoints of reacting all remaining polymerizable unsaturated groups and sufficiently deactivating the peroxide, at which radicals in the polymerization initiator are likely to be generated, and at a temperature approximately equal to or higher than the half-life temperature of the peroxide, and is preferably in the range of, for example, 60 to 180° C., more preferably in the range of 70 to 150° C. The time for which the reaction solution is held is preferably in the range of 0.5 to 20 hours, more preferably in the range of 1 to 10 hours.

[0061] (Step (ii): Polymerizable unsaturated group formation step) Step (ii) is a step of producing a (meth)acrylate resin as a reaction product by reacting the reactive functional group-containing acrylic resin (A1) obtained in step (i) with a functional group capable of reacting with the reactive functional group and a compound (A2) containing a polymerizable unsaturated group as essential raw materials. The reaction in step (ii) is carried out in the presence of a basic catalyst under an atmosphere of an oxygen-containing gas (b1) and an inert gas (b2) while stirring. By the reaction of the acrylic resin (A1) with the compound (A2) in step (ii), a polymerizable unsaturated group derived from the compound (A2) is introduced into the (meth)acrylate resin as the reaction product. Note that, when a part or all of the reactive functional groups in the reactive functional group-containing acrylic resin (A1) are carboxyl groups, in the above reaction, not all of the carboxyl groups (reactive functional groups) react with the "functional group capable of reacting with the reactive functional group" in the compound (A2), and some of them may remain as unreacted carboxyl groups. In this case, the unreacted carboxyl group corresponds to an acid group, and the (meth)acrylate resin obtained in step (ii) is a resin containing an acid group and a polymerizable unsaturated group.

[0062] <Compound (A2)> The compound (A2) is a compound capable of forming a polymerizable unsaturated group on the acrylic resin by reacting with the reactive functional group-containing acrylic resin (A1). For example, when the reactive functional group-containing acrylic resin (A1) is an epoxy group- or carboxyl group-containing acrylic resin, the compound (A2) is an unsaturated monobasic acid or an epoxy group-containing (meth)acrylate. Specifically, when the reactive functional group-containing acrylic resin (A1) is an epoxy group-containing acrylic resin, the compound (A2) is an unsaturated monobasic acid. Also, when the reactive functional group-containing acrylic resin (A1) is a carboxyl group-containing acrylic resin, the compound (A2) is an epoxy group-containing (meth)acrylate. Below, examples of the compound (A2) will be described using these cases as examples.

[0063] <Unsaturated monobasic acid> The "unsaturated monobasic acid" used as compound (A2) refers to a compound containing an acid group and a polymerizable unsaturated group in one molecule. The "acid group" contained in the unsaturated monobasic acid corresponds to the "functional group capable of reacting with the reactive functional group" in compound (A2). Examples of the acid group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Among these, a carboxyl group is preferred as the acid group from the viewpoint of obtaining a (meth)acrylate resin that is a resin material capable of obtaining a cured product having excellent photosensitivity, excellent heat resistance, heat yellowing resistance, and reflectivity. Examples of the unsaturated monobasic acid include the compounds exemplified above as the carboxyl group-containing (meth)acrylic monomer. In this case, the carboxyl group in the carboxyl group-containing (meth)acrylic monomer corresponds to the "functional group capable of reacting with the reactive functional group", and the vinylidene structure-containing group such as a (meth)acryloyl group in the carboxyl group-containing (meth)acrylic monomer corresponds to the "polymerizable unsaturated group". These unsaturated monobasic acids can be used alone or in combination of two or more kinds.

[0064] <Epoxy group-containing (meth)acrylate> The "epoxy group-containing (meth)acrylate" used as the compound (A2) refers to a compound containing an epoxy group and a (meth)acryloyl group in one molecule, as defined above. The "epoxy group" contained in the epoxy group-containing (meth)acrylate corresponds to the "functional group capable of reacting with the reactive functional group" in the compound (A2). The "(meth)acryloyl group" contained in the epoxy group-containing (meth)acrylate corresponds to the "polymerizable unsaturated group" in the compound (A2). Examples of the epoxy group-containing (meth)acrylate include the compounds exemplified above as the epoxy group-containing (meth)acrylic monomer. These epoxy group-containing (meth)acrylates can be used alone or in combination of two or more.

[0065] <Amount of compound (A2) used> When the acrylic resin (A1) is an epoxy group-containing acrylic resin and the compound (A2) is an unsaturated monobasic acid, from the viewpoint of obtaining a (meth)acrylate resin that serves as a resin material capable of obtaining a cured product having excellent photosensitivity, and excellent heat resistance, heat yellowing resistance, and reflectivity, the amount of compound (A2) used is preferably in the range of 0.5 to 1.1 mol, more preferably 0.55 to 1.05 mol, per mol of epoxy group (corresponding to "reactive functional group") contained in the acrylic resin (A1).

[0066] When the acrylic resin (A1) is a carboxyl group-containing acrylic resin and the compound (A2) is an epoxy group-containing (meth)acrylate, in order to obtain a (meth)acrylate resin that is a resin material containing an acid group and a polymerizable unsaturated group and that has excellent photosensitivity and is capable of obtaining a cured product having excellent heat resistance, heat yellowing resistance and reflectivity, the amount of the compound (A2) used is preferably less than the number of moles of the carboxyl groups (corresponding to the "reactive functional groups") contained in the acrylic resin (A1), and the number of moles of the compound (A2) is preferably in the range of 0.5 to 1.0 mole, more preferably 0.55 to 0.9 mole, per mole of the carboxyl groups (corresponding to the "reactive functional groups") contained in the acrylic resin (A1). In this way, by making the amount of compound (A2) used less than the number of moles of carboxyl groups (corresponding to "reactive functional groups") contained in the acrylic resin (A1), acid groups remain, and a (meth)acrylate resin containing acid groups can be obtained.

[0067] <Basic catalyst> The reaction in step (ii) is carried out in the presence of a basic catalyst, such as N-methylmorpholine, pyridine, 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), tri-n-butylamine or dimethylbenzylamine, trimethylamine, dimethylethylamine, diethylmethylamine, triethylamine, dimethylpropylamine, diethylpropylamine, dipropylmethylamine, di ... amine, dipropylethylamine, tripropylamine, dimethylbutylamine, diethylbutylamine, dibutylmethylamine, dibutylethylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, butylamine, octylamine, monoethanolamine, diethanolamine, triethanolamine, imidazole, 1-methylimidazole, 2,4-dimethylimidazole, 1,4- amine compounds such as diethylimidazole, 2-ethyl-4-methylimidazole, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(N-phenyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, and tetramethylammonium hydroxide; quaternary ammonium salts such as trioctylmethylammonium chloride and trioctylmethylammonium acetate; phosphine compounds such as trimethylphosphine, tributylphosphine, and triphenylphosphine; phosphonium salts such as tetramethylphosphonium chloride, tetraethylphosphonium chloride, tetrapropylphosphonium chloride, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, trimethyl(2-hydroxypropyl)phosphonium chloride, triphenylphosphonium chloride, and benzylphosphonium chloride;Examples of suitable basic catalysts include organic tin compounds such as dibutyltin dilaurate, octyltin trilaurate, octyltin diacetate, dioctyltin diacetate, dioctyltin dineodecanoate, dibutyltin diacetate, tin octylate, and 1,1,3,3-tetrabutyl-1,3-dodecanoyldistannoxane; organic metal compounds such as zinc octylate and bismuth octylate; organic tin compounds such as tin octanoate; and inorganic metal compounds. Among these, from the viewpoint of obtaining a (meth)acrylate resin that is a resin material capable of obtaining a cured product having excellent photosensitivity, excellent heat resistance, heat yellowing resistance, and reflectivity, a phosphine compound or a phosphonium salt is preferred, a phosphine compound is more preferred, and triphenylphosphine is even more preferred. These basic catalysts can be used alone or in combination of two or more.

[0068] The amount of the basic catalyst used is preferably within a range of 0.01 to 5 parts by mass, and more preferably 0.1 to 1 part by mass, per 100 parts by mass of the total amount of the polymerization raw materials for the acrylic resin (A1) and the compound (A2).

[0069] <Amount of polymerization inhibitor in step (ii)> If no polymerization inhibitor is present in the reaction system during the reaction of step (ii), the (meth)acrylate resin and / or unreacted compound (A2) will undergo a polymerization reaction during step (ii) and will be prone to deterioration such as gelation. In order to prevent such deterioration such as gelation, it is preferable that the reaction system of step (ii) contains a polymerization inhibitor in an amount equal to or greater than the minimum amount required to prevent gelation. An additional polymerization inhibitor may be added to the reaction system before or during step (ii). Examples of the polymerization inhibitor include those mentioned above. These polymerization inhibitors may be used alone or in combination of two or more. The total amount of the polymerization inhibitor relative to the total amount of solids of the raw materials used in step (ii) is preferably in the range of 50 to 10000 ppm, more preferably in the range of 100 to 5000 ppm. The amount of the polymerization inhibitor may be adjusted to the above range by adding additional polymerization inhibitor to the reaction system before or during step (ii). The amount of the polymerization inhibitor in the compound (A2) used in the step (ii) may be 500 ppm or less, preferably 400 ppm or less, and more preferably 300 ppm or less, based on the solid content of the compound (A2). The amount of the polymerization inhibitor in the (meth)acrylate resin obtained in the step (ii) is preferably in the range of 50 ppm to 10,000 ppm, more preferably in the range of 100 to 5,000 ppm, based on the solid content of the (meth)acrylate resin.

[0070] <Reaction solution in step (ii)> The reaction solution in step (ii) may be prepared by adding components for the reaction in step (ii), such as compound (A2) and a basic catalyst, to the reaction solution after the completion of step (i) without performing solvent exchange after the completion of step (i). Alternatively, the reaction solution in step (ii) may be prepared by performing solvent exchange on the reaction solution after the completion of step (i), and adding components for the reaction in step (ii), such as compound (A2) and a basic catalyst, to the solvent-exchanged reaction solution. From the viewpoint of simplicity of operation and avoiding a decrease in the yield of the reaction product in step (i) due to solvent exchange, it is preferable not to perform solvent exchange.

[0071] <Addition method of additional component in step (ii)> The additional components for the reaction in step (ii), such as compound (A2) and a basic catalyst, may be added to the reaction solution all at once or gradually. The components for the reaction in step (ii) may be added to the reaction solution as they are, or may be added to the reaction solution after being dissolved in an organic solvent. The organic solvents that can be used to dissolve the additional components in step (ii) may be the organic solvents exemplified in the explanation of step (i) above, and may be the same type of organic solvent as the organic solvent into which liquid (L1) and liquid (L2) are dropped in step (i).

[0072] <Reaction atmosphere in step (ii)> The reaction in step (ii) is carried out under an atmosphere of an oxygen-containing gas (b1) and an inert gas (b2).

[0073] <Gas containing oxygen (b1)> The oxygen-containing gas (b1) is not particularly limited, but for example, oxygen (O 2 ) gas and air. The oxygen-containing gas (b1) is the gas that adds oxygen (O 2 From the viewpoint of supplying the reactant gas, it is preferably supplied to the gas phase portion in the reaction vessel or into the reaction liquid (for example, by blowing the reactant gas into the reaction liquid from above or below the liquid surface), and more preferably by blowing the reactant gas into the reaction liquid (for example, by blowing the reactant gas into the reaction liquid from below the liquid surface).

[0074] <Inert gas (b2)> The inert gas (b2) is not particularly limited, but may be, for example, nitrogen (N 2 ) gas; rare gases such as helium, neon, argon, krypton, xenon, etc.; and mixed gases thereof. The inert gas (b2) is preferably supplied to the gas phase portion in the reaction vessel from the viewpoint of suppressing the inclusion of unnecessary gas components and not contributing to the reaction, and can be supplied, for example, from above the liquid surface of the reaction liquid.

[0075] <Oxygen concentration in step (ii)> The oxygen concentration in the reaction system in which step (ii) is carried out is in the range of 2 to 12% by mass, preferably in the range of 4 to 10% by mass, and more preferably in the range of 5 to 9% by mass. The oxygen concentration in the reaction system refers to the oxygen (O 2 ) concentration. The oxygen concentration in the reaction system can be adjusted by the supply amount of the oxygen-containing gas (b1) and the inert gas (b2). By setting the oxygen concentration in the reaction system within the above range, it is possible to avoid the risk of explosion due to an excessive oxygen concentration during the reaction, and ensure safety during production, and it is also possible to prevent deterioration such as gelation of the (meth)acrylate resin and / or the unreacted compound (A2), and it is possible to obtain a (meth)acrylate resin that is a resin material capable of obtaining a cured product having excellent photosensitivity, excellent heat resistance, heat yellowing resistance, and reflectivity.

[0076] <Stirring in step (ii)> The reaction in step (ii) is carried out with stirring. The stirring is performed with a stirring power per unit volume of 0.2 to 8 kW / m 3 The range is preferably 0.5 to 6 kW / m 3 More preferably, the range is 1 to 5 kW / m 3 By setting the unit power during stirring within the above range, oxygen in the liquid is highly dispersed, and thus it is possible to obtain a (meth)acrylate resin that has excellent photosensitivity as a cured product, and that also has excellent heat resistance, heat yellowing resistance, and reflectivity.

[0077] <Reaction temperature and time in step (ii)> In the reaction of step (ii), in order to sufficiently proceed with the step of forming a polymerizable unsaturated group in the (meth)acrylate resin, the reaction temperature is, for example, preferably in the range of 60 to 160° C., more preferably in the range of 80 to 150° C., from the viewpoint of suppressing side reactions and shortening the reaction time. The reaction time is preferably in the range of 1 to 30 hours, more preferably in the range of 1 to 24 hours.

[0078] (Step (iii): Acid group formation step) The method of the present invention may, as an optional step, comprise the steps of: Step (iii): A step of reacting the (meth)acrylate resin obtained in step (ii) with a polybasic acid anhydride (C) to form an acid group in the (meth)acrylate resin. It may further include. When obtaining a (meth)acrylate resin as an acid group- and polymerizable unsaturated group-containing resin, if the acrylic resin (A1) is an epoxy group-containing acrylic resin and the compound (A2) is an unsaturated monobasic acid, the (meth)acrylate resin obtained in step (ii) usually does not contain an acid group, so that an acid group can be introduced into the (meth)acrylate resin by step (iii). In step (ii), when the epoxy group contained in the acrylic resin (A1) reacts with the compound (A2) which is an unsaturated monobasic acid, a (meth)acrylate resin containing a hydroxyl group is generally obtained. In step (iii), for example, the hydroxyl group in the (meth)acrylate resin obtained in step (ii) reacts with the polybasic acid anhydride (C) to introduce an acid group. Here, in order to increase the amount of acid group introduction in step (iii), it is preferable that in step (ii), the epoxy group contained in the acrylic resin (A1) reacts with the compound (A2) which is an unsaturated monobasic acid as much as possible. Therefore, the molar amount of the compound (A2) used is preferably equal to or as close as possible to the molar amount of the epoxy groups (corresponding to "reactive functional groups") contained in the acrylic resin (A1). On the other hand, when the acrylic resin (A1) is a carboxyl group-containing acrylic resin and the compound (A2) is an epoxy group-containing (meth)acrylate, the carboxyl group remaining in the acrylic resin (A1) without reacting with the compound (A2) remains as an acid group in the (meth)acrylate resin obtained in step (ii), and the carboxyl group in the acrylic resin (A1) reacts with the compound (A2) to form an epoxy group (corresponding to a "reactive functional group"). Thus, the (meth)acrylate resin obtained in step (ii) contains an acid group, but the amount of the acid group introduced can be increased by carrying out the reaction in step (iii). When a (meth)acrylate resin is obtained as the final product as the acid group- and polymerizable unsaturated group-containing resin, the curable resin composition containing the (meth)acrylate resin and the photopolymerization initiator can be used as a coating agent or adhesive, and as a coating agent, it is particularly suitable for use in solder resist applications. In addition, the cured product obtained by curing the curable resin composition, and the insulating material and resist member using the cured product can be used as a coating, and as a coating, it is particularly suitable for use in solder resist applications.

[0079] <Polybasic acid anhydride (C)> Examples of the polybasic acid anhydride (C) include aliphatic polybasic acid anhydrides (saturated aliphatic polybasic acid anhydrides, unsaturated aliphatic polybasic acid anhydrides), alicyclic polybasic acid anhydrides (saturated alicyclic polybasic acid anhydrides, unsaturated alicyclic polybasic acid anhydrides), aromatic polybasic acid anhydrides, and acid halides thereof.

[0080] The term "saturated aliphatic polybasic acid anhydride" refers to a compound having a linear or branched saturated aliphatic hydrocarbon structure and a polybasic acid anhydride group (but not including an alicyclic structure or an aromatic ring). Examples of the saturated aliphatic polybasic acid anhydride include anhydrides of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and 1,2,3,4-butanetetracarboxylic acid.

[0081] The term "unsaturated aliphatic polybasic acid anhydride" refers to a compound having a linear or branched unsaturated aliphatic hydrocarbon structure and a polybasic acid anhydride group (but not including an alicyclic structure or an aromatic ring). Examples of the unsaturated aliphatic polybasic acid anhydride include the acid anhydrides of maleic acid, fumaric acid, citraconic acid, itaconic acid, and glutaconic acid.

[0082] The term "saturated alicyclic polybasic acid anhydride" refers to a compound having a saturated alicyclic structure and a polybasic acid anhydride group (which may further have a linear or branched aliphatic hydrocarbon structure, but does not contain an aromatic ring). Examples of the saturated alicyclic polybasic acid anhydride include anhydrides of hexahydrophthalic acid (cyclohexanedicarboxylic acid), methylhexahydrophthalic acid (methylcyclohexanedicarboxylic acid), cyclohexanetricarboxylic acid, cyclohexanetetracarboxylic acid, bicyclo[2.2.1]heptane-2,3-dicarboxylic acid, and methylbicyclo[2.2.1]heptane-2,3-dicarboxylic acid.

[0083] The "unsaturated alicyclic polybasic acid anhydride" is a compound having an unsaturated alicyclic structure and a polybasic acid anhydride group (which may further have a linear or branched aliphatic hydrocarbon structure, but does not contain an aromatic ring). Examples of the unsaturated alicyclic polybasic acid anhydride include tetrahydrophthalic acid (cyclohexene dicarboxylic acid) and 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride.

[0084] The "aromatic polybasic acid anhydride" is a compound having an aromatic ring and a polybasic acid anhydride group (which may further have a linear or branched aliphatic hydrocarbon structure and / or an alicyclic structure). Examples of the aromatic polybasic acid anhydride include anhydrides of phthalic acid, trimellitic acid, pyromellitic acid, naphthalene dicarboxylic acid, naphthalene tricarboxylic acid, naphthalene tetracarboxylic acid, biphenyl dicarboxylic acid, biphenyl tricarboxylic acid, biphenyl tetracarboxylic acid, and benzophenone tetracarboxylic acid.

[0085] Examples of the acid halides include acid fluorides, acid chlorides, acid bromides, and acid iodides of the polybasic acid anhydrides exemplified as the aliphatic polybasic acid anhydrides, the alicyclic polybasic acid anhydrides, or the aromatic polybasic acid anhydrides.

[0086] As the polybasic acid anhydride (C), an alicyclic polybasic acid anhydride is preferable, and a saturated alicyclic polybasic acid anhydride is more preferable. Among them, hexahydrophthalic anhydride (hexahydroisobenzofuran-1,3-dione), which is an acid anhydride of hexahydrophthalic acid, and methylhexahydrophthalic anhydride (3-methyl-8-oxabicyclo[4.3.0]nonane-7,9-dione), which is an acid anhydride of methylhexahydrophthalic acid, and the like are even more preferable.

[0087] These polybasic acid anhydrides (C) can be used alone or in combination of two or more kinds.

[0088] The amount of the polybasic acid anhydride (C) used is preferably in the range of 0.05 to 1.05 mol relative to 1 mol of reactive functional group contained in the reactive functional group-containing acrylic resin (A1), from the viewpoint of being suitable for use in coating agents and adhesives, particularly solder resist applications, when made into a curable resin composition, more preferably in the range of 0.1 to 1.05 mol, and even more preferably in the range of 0.15 to 0.95 mol. When the acrylic resin (A1) is an epoxy group-containing acrylic resin and the compound (A2) is an unsaturated monobasic acid, the amount of the polybasic acid anhydride (C) used is preferably in the range of 0.3 to 1.0 mol relative to 1 mol of reactive functional group contained in the reactive functional group-containing acrylic resin (A1), more preferably in the range of 0.3 to 0.95 mol, and even more preferably in the range of 0.4 to 0.95 mol. On the other hand, when the acrylic resin (A1) is a carboxyl group-containing acrylic resin and the compound (A2) is an epoxy group-containing (meth)acrylate, the amount of the polybasic acid anhydride (C) used is preferably in the range of 0.05 to 0.9 mol, more preferably in the range of 0.1 to 0.8 mol, and even more preferably in the range of 0.1 to 0.5 mol, per mol of the reactive functional group contained in the reactive functional group-containing acrylic resin (A1).

[0089] <Polymerization inhibitor in step (iii)> If no polymerization inhibitor is present in the reaction system when the reaction of step (iii) is carried out, the (meth)acrylate resin and / or unreacted compound (A2) will undergo a polymerization reaction during step (iii) and will easily cause deterioration such as gelation, so it is preferable that the reaction system of step (iii) contains a minimum amount of polymerization inhibitor to prevent gelation. The polymerization inhibitor may be added after the reaction of step (ii), or may not be added after the reaction of step (ii) and may be used as the polymerization inhibitor remaining in the reaction liquid after the reaction of step (ii).

[0090] <Basic catalyst in step (iii)> If the basic catalyst is not present in the reaction system when the reaction of step (iii) is carried out, acid groups are not sufficiently formed, so it is preferable that the reaction system of step (iii) contains a minimum amount of basic catalyst sufficient to form acid groups. The basic catalyst may be added after the reaction of step (ii), or may be used as the basic catalyst remaining in the reaction solution after the reaction of step (ii) without being added after the reaction of step (ii).

[0091] <Organic solvent in step (iii)> If no organic solvent is present in the reaction system when the reaction of step (iii) is carried out, the reaction will not proceed sufficiently or will be prone to deterioration such as gelation, so it is preferable that the reaction system of step (iii) contains a minimum amount of organic solvent that allows the reaction to proceed sufficiently. In step (iii), an organic solvent may be added to the reaction solution after the reaction of step (ii), or the organic solvent remaining in the reaction solution after the reaction of step (ii) may be used as the organic solvent in step (iii) without adding an organic solvent after the reaction of step (ii). As the organic solvent that can be added in step (iii), the organic solvent exemplified in the explanation of step (i) above can be used, and the same type of organic solvent as the organic solvent into which the liquid (L1) and the liquid (L2) are dropped in step (i) can be used.

[0092] <Reaction solution in step (iii)> The reaction liquid in step (iii) may be prepared by adding components for the reaction in step (iii), such as polybasic acid anhydride (C), to the reaction liquid after the completion of step (ii) without performing solvent exchange after the completion of step (ii). Alternatively, the reaction liquid in step (iii) may be prepared by performing solvent exchange on the reaction liquid after the completion of step (ii) and adding components for the reaction in step (iii), such as polybasic acid anhydride (C), to the solvent-exchanged reaction liquid. From the viewpoint of simplicity of operation and avoiding a decrease in the yield of the reaction product in step (ii) due to solvent exchange, it is preferable not to perform solvent exchange.

[0093] <Addition method of additional component in step (iii)> The additional components for the reaction of step (iii), such as polybasic acid anhydride (C), may be added to the reaction solution all at once or gradually. The components for the reaction of step (iii) may be added to the reaction solution as they are, or may be added to the reaction solution after being dissolved in an organic solvent. The organic solvents that can be used to dissolve the additional components in step (iii) may be the organic solvents exemplified in the explanation of step (i) above, and may be the same type of organic solvent as the organic solvent into which the liquid (L1) and the liquid (L2) are dropped in step (i).

[0094] <Reaction atmosphere in step (iii)> The atmosphere in which the reaction in step (iii) is carried out is preferably the same as that in step (ii), in order to ensure safety during production by avoiding the risk of explosion due to an excessive oxygen concentration during the reaction, and to prevent deterioration such as gelation of the (meth)acrylate resin, the unreacted acrylic resin (A1), and / or the unreacted compound (A2).

[0095] <Stirring in step (iii)> The reaction in step (iii) may be carried out while standing or while stirring, but it is preferable to carry out the reaction while stirring in order to obtain a (meth)acrylate resin that is a resin material capable of obtaining a cured product having excellent photosensitivity, heat resistance, heat yellowing resistance, and reflectivity. When the reaction in step (iii) is carried out while stirring, the stirring power per unit volume is preferably the same as that in step (ii).

[0096] <Reaction temperature and time in step (iii)> In the reaction of step (iii), in order to sufficiently advance the formation of acid groups in the (meth)acrylate resin, and from the viewpoints of suppressing side reactions and shortening the reaction time, the reaction temperature is, for example, preferably in the range of 60 to 160° C., and more preferably in the range of 80 to 150° C. The reaction time is preferably in the range of 0.5 to 30 hours, and more preferably in the range of 1 to 15 hours.

[0097] ((Meth)acrylate resin) The (meth)acrylate resin obtained by the method of the present invention is a polymerizable unsaturated group-containing resin, and has excellent photosensitivity as a cured product, and can have excellent heat resistance, heat yellowing resistance, and reflectivity. In addition, the method of the present invention can obtain a (meth)acrylate resin as an acid group and polymerizable unsaturated group-containing resin, and when the (meth)acrylate resin is made into a curable resin composition, it can be used as a coating agent or adhesive, and as a coating agent, it is particularly suitable for use in solder resist applications. In addition, the cured product obtained by curing the curable resin composition, and the insulating material and resist member using the cured product can be used as a coating, and as a coating, it is particularly suitable for use in solder resist applications.

[0098] The (meth)acrylate resin obtained by the method of the present invention has a viscosity at 40°C of 2,000 mPa·s or less, preferably 1,500 mPa·s or less, more preferably 1,000 mPa·s or less, and even more preferably 700 mPa·s or less, from the viewpoint of being a resin material from which a cured product having excellent photosensitivity, and excellent heat resistance, resistance to heat yellowing, and reflectivity can be obtained. The (meth)acrylate resin obtained by the method of the present invention has an excellent photosensitivity, and from the viewpoint of being a resin material capable of obtaining a cured product having excellent heat resistance, heat yellowing resistance, and reflectivity, the acid value of the solid content is preferably 45 mgKOH / g to 130 mgKOH / g, more preferably 50 mgKOH / g to 120 mgKOH / g, and even more preferably 55 mgKOH / g to 100 mgKOH / g. The "acid value of the solid content" is a value measured by neutralization titration method, and specifically, can be calculated by the method described in the Examples below. The (meth)acrylate resin obtained by the method of the present invention has excellent photosensitivity, and is capable of obtaining a cured product having excellent heat resistance, heat yellowing resistance, and reflectivity. Therefore, the polymerizable unsaturated group equivalent is preferably 280 g / equivalent to 500 g / equivalent, more preferably 300 g / equivalent to 450 g / equivalent, and even more preferably 320 g / equivalent to 420 g / equivalent. In this specification, the "polymerizable unsaturated group equivalent" is an amount that is an index of the amount of polymerizable unsaturated groups contained in a molecule, and if the compounds have the same molecular weight, the smaller the value of the polymerizable unsaturated group equivalent, the more the amount of polymerizable unsaturated groups introduced tends to be. The "polymerizable unsaturated group equivalent" can be calculated by the method described in the examples below. The amount of polymerization inhibitor relative to the solid content of the (meth)acrylate resin in the (meth)acrylate resin obtained by the method of the present invention is preferably 1000 ppm or less, more preferably 900 ppm or less, and even more preferably 800 ppm or less, from the viewpoint of being able to obtain a resin material from which a cured product having excellent photosensitivity, and excellent heat resistance, heat yellowing resistance, and reflectivity can be obtained.

[0099] (Method for producing curable resin composition) The (meth)acrylate resin obtained by the method of the present invention can be used as a curable resin composition by adding a photopolymerization initiator. Such a curable resin composition can be produced by a method for producing a curable resin composition, which includes a step of mixing the (meth)acrylate resin obtained by the method for producing a (meth)acrylate resin of the present invention with a photopolymerization initiator to obtain a curable resin composition.

[0100] Examples of the photopolymerization initiator include photoradical initiators such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2'-dimethoxy-1,2-diphenylethan-1-one, diphenyl(2,4,6-trimethoxybenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone.

[0101] Examples of commercially available photopolymerization initiators include "Omnirad 1173", "Omnirad 184", "Omnirad 127", "Omnirad 2959", "Omnirad 369", "Omnirad 379", "Omnirad 907", "Omnirad 4265", "Omnirad 1000", "Omnirad 651", "Omnirad TPO", "Omnirad 819", "Omnirad 2022", "Omnirad 2100", "Omnirad 754", "Omnirad 784", "Omnirad 500", "Omnirad 81" (manufactured by IGM), "KAYACURE DETX", "KAYACURE MBP", "KAYACURE DMBI", "KAYACURE EPA", "KAYACURE OA" (manufactured by Nippon Kayaku Co., Ltd.), "Vicure 10", "Vicure Examples of such polymers include "55" (manufactured by Stauffer Chemical Co.), "Trigonal P1" (manufactured by AKZO Corporation), "Sandoray 1000" (manufactured by SANDOZ Corporation), "Deep" (manufactured by Upjohn Corporation), "Quantacure PDO", "Quantacure ITX", "Quantacure EPD" (manufactured by Ward Blenkinsop Corporation), and "Runtecure (registered trademark) 1104" (manufactured by Runtec Corporation).

[0102] The amount of the photopolymerization initiator added is preferably within a range of, for example, 0.5 to 20% by mass in the curable resin composition.

[0103] <Other resins having polymerizable unsaturated groups> The curable resin composition obtained by the method for producing a curable resin composition may further contain a resin having a polymerizable unsaturated group other than the (meth)acrylate resin obtained by the method for producing a (meth)acrylate resin of the present invention (hereinafter, also referred to as "resin having other polymerizable unsaturated groups"). That is, the method for producing a curable resin composition may include a step of mixing the (meth)acrylate resin obtained by the method for producing a (meth)acrylate resin of the present invention and a resin having other polymerizable unsaturated groups in addition to a photopolymerization initiator to obtain a curable resin composition. Examples of resins having such polymerizable unsaturated groups include, for example, resins having acid groups and polymerizable unsaturated groups described in JP 2023-003576 A, and these resins can be used in the manner described in the paragraph.

[0104] Examples of the acid group contained in such a resin include those exemplified as the acid group contained in the above-mentioned “unsaturated monobasic acid.” Among these, a carboxyl group is preferred as the acid group because it exhibits superior developability.

[0105] Examples of the polymerizable unsaturated group contained in such a resin include those exemplified in the above definition.

[0106] <Compound having a polymerizable unsaturated group> The curable resin composition obtained by the method for producing a curable resin composition may further contain a compound having a polymerizable unsaturated group. That is, the method for producing a curable resin composition may include a step of obtaining a curable resin composition by mixing the (meth)acrylate resin obtained by the method for producing a (meth)acrylate resin of the present invention with a compound having a polymerizable unsaturated group in addition to a photopolymerization initiator. Such a compound having a polymerizable unsaturated group is typically a compound having no acid group.

[0107] Examples of the compound having a polymerizable unsaturated group include (meth)acrylate compounds. Specific examples of the compound include aliphatic mono(meth)acrylate compounds such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, pentyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and octyl(meth)acrylate; alicyclic mono(meth)acrylate compounds such as cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, and adamantyl mono(meth)acrylate. Mono(meth)acrylate compounds; heterocyclic mono(meth)acrylate compounds such as glycidyl(meth)acrylate and tetrahydrofurfuryl acrylate; benzyl(meth)acrylate, phenyl(meth)acrylate, phenylbenzyl(meth)acrylate, phenoxy(meth)acrylate, phenoxyethyl(meth)acrylate, phenoxyethoxyethyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, phenoxybenzyl(meth)acrylate, benzylbenzyl(meth)acrylate, phenyl Mono(meth)acrylate compounds such as aromatic mono(meth)acrylate compounds such as diphenyloxyethyl (meth)acrylate: (poly)oxyalkylene-modified mono(meth)acrylate compounds in which a polyoxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain has been introduced into the molecular structure of the various mono(meth)acrylate monomers described above; lactone-modified mono(meth)acrylate compounds in which a (poly)lactone structure has been introduced into the molecular structure of the various mono(meth)acrylate compounds described above; ethylene glycol di( aliphatic di(meth)acrylate compounds such as 1,4-cyclohexanedimethanol di(meth)acrylate, norbornane di(meth)acrylate, norbornane dimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, etc.; alicyclic di(meth)acrylate compounds such as 1,4-cyclohexanedimethanol di(meth)acrylate, norbornane di(meth)acrylate, norbornane dimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, etc.Aromatic di(meth)acrylate compounds such as biphenol di(meth)acrylate and bisphenol di(meth)acrylate; polyoxyalkylene-modified di(meth)acrylate compounds in which a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain has been introduced into the molecular structure of the various di(meth)acrylate compounds; lactone-modified di(meth)acrylate compounds in which a (poly)lactone structure has been introduced into the molecular structure of the various di(meth)acrylate compounds; aliphatic tri(meth)acrylate compounds such as trimethylolpropane tri(meth)acrylate and glycerin tri(meth)acrylate; (poly)oxyalkylene chains such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain have been introduced into the molecular structure of the various di(meth)acrylate compounds; )oxyalkylene-modified tri(meth)acrylate compounds; lactone-modified tri(meth)acrylate compounds obtained by introducing a (poly)lactone structure into the molecular structure of the aliphatic tri(meth)acrylate compounds; tetrafunctional or higher aliphatic poly(meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.; tetrafunctional or higher (poly)oxyalkylene-modified poly(meth)acrylate compounds obtained by introducing a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, a (poly)oxytetramethylene chain, etc. into the molecular structure of the aliphatic poly(meth)acrylate compounds; tetrafunctional or higher lactone-modified poly(meth)acrylate compounds obtained by introducing a (poly)lactone structure into the molecular structure of the aliphatic poly(meth)acrylate compounds;Hydroxyethyl (meth)acrylate, Hydroxypropyl (meth)acrylate, Trimethylolpropane (meth)acrylate, Trimethylolpropane di(meth)acrylate, Pentaerythritol (meth)acrylate, Pentaerythritol di(meth)acrylate, Pentaerythritol tri(meth)acrylate, Dipentaerythritol (meth)acrylate, Dipentaerythritol di(meth)acrylate, Dipentaerythritol tri(meth)acrylate (meth)acrylate compounds having a hydroxyl group, such as dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane (meth)acrylate, ditrimethylolpropane di(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate; (meth)acrylate compounds having a hydroxyl group, such as (poly)oxyethylene chains, (poly)oxypropylene chains, (poly)oxytetramethylolpropane chains, (poly)oxyethylene chains, (poly)oxypropylene chains, (poly)oxyethylene ... lactone modified compounds having a (poly)lactone structure introduced into the molecular structure of the (meth)acrylate compound having a hydroxyl group; (meth)acrylate compounds having an isocyanate group, such as 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and 1,1-bis(acryloyloxymethyl)ethyl isocyanate; (meth)acrylate compounds having an epoxy group, such as (meth)acrylate monomers having a glycidyl group, such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and epoxycyclohexylmethyl (meth)acrylate; and (meth)acrylate compounds having an epoxy group, such as mono(meth)acrylates of diglycidyl ether compounds of hydroxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether, biphenol diglycidyl ether, and bisphenol diglycidyl ether. The compound having a polymerizable unsaturated group may be used alone or in combination of two or more kinds.

[0108] (Method of producing the cured product) The curable resin composition obtained by the above-mentioned method for producing a curable resin composition can be used to obtain a cured product. The method for producing a cured product includes a step of curing the curable resin composition obtained by the above-mentioned method for producing a curable resin composition to obtain a cured product. The step of curing the curable resin composition to obtain a cured product can be performed, for example, by irradiating the curable resin composition with active energy rays. Examples of the active energy rays include ionizing radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays. In addition, when ultraviolet rays are used as the active energy rays, irradiation may be performed under an inert gas atmosphere such as nitrogen gas, or under an air atmosphere in order to efficiently carry out a curing reaction by ultraviolet rays.

[0109] As a source of ultraviolet light, ultraviolet lamps are generally used from the viewpoints of practicality and economy, and specific examples include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, gallium lamps, metal halide lamps, sunlight, LEDs, etc.

[0110] The cumulative amount of the active energy rays is not particularly limited, but is preferably 0.1 to 50 kJ / m 2 is preferably 0.5 to 10 kJ / m 2 It is more preferable that the integrated light amount is within the above range, since it is possible to prevent or suppress the occurrence of uncured portions.

[0111] The irradiation of the active energy rays may be carried out in one step or in two or more steps.

[0112] (Method of manufacturing insulating materials, method of manufacturing resist materials) The cured product obtained by the above-mentioned method for producing a cured product is obtained by using a curable resin composition having high photosensitivity, and has excellent heat resistance, heat yellowing resistance and reflectivity, and therefore can be suitably used, for example, as a solder resist, an interlayer insulating material, a packaging material, an underfill material, a package adhesive layer for circuit elements, etc., in semiconductor device applications, or as an adhesive layer between an integrated circuit element and a circuit board. In addition, it can be suitably used as a thin film transistor protective film, a liquid crystal color filter protective film, a pigment resist for color filters, a resist for black matrices, a spacer, etc., in thin display applications represented by LCD and OELD. Among these, it can be particularly suitably used for solder resist applications. The method for producing an insulating material and the method for producing a resist member are characterized by using a cured product obtained by the above-mentioned method for producing a cured product.

[0113] The method for producing an insulating material of the present invention is characterized by using a cured product obtained by the above-mentioned method for producing a cured product.

[0114] The method for producing a resist member of the present invention is characterized by using a cured product obtained by the above-mentioned method for producing a cured product. The method for producing a resist member of the present invention can use a cured product obtained by, for example, applying a curable resin composition obtained by the method for producing a curable resin composition onto a substrate, evaporating and drying the organic solvent at a temperature range of about 60 to 100°C, exposing the composition to active energy rays through a photomask having a desired pattern formed thereon, developing the unexposed areas with an alkaline aqueous solution, and further heating and curing the composition at a temperature range of about 140 to 200°C.

[0115] Examples of the substrate include metal foils such as copper foil and aluminum foil. EXAMPLES

[0116] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the examples given below.

[0117] <Weight average molecular weight (Mw) measurement> In the present examples, the weight average molecular weight (Mw) is a value measured using gel permeation chromatography (GPC) under the following conditions.

[0118] Measurement equipment: Tosoh Corporation "HLC-8420 GPC" Column: Tosoh Corporation guard column "HXL-L" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G3000HXL" + Tosoh Corporation "TSK-GEL G4000HXL" Detector: RI (differential refractometer) Data processing: Tosoh Corporation's "GPC Workstation EcoSEC-WorkStation" Measurement conditions: Column temperature 40℃ Developing solvent: Tetrahydrofuran Flow rate 1.0mL / min Standard: In accordance with the measurement manual for the "GPC Workstation EcoSEC-WorkStation," the following monodisperse polystyrene with known molecular weight was used. (Polystyrene used) "A-500" manufactured by Tosoh Corporation "A-1000" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation "F-10" manufactured by Tosoh Corporation "F-20" manufactured by Tosoh Corporation "F-40" manufactured by Tosoh Corporation "F-80" manufactured by Tosoh Corporation "F-128" manufactured by Tosoh Corporation Sample: 100μL of tetrahydrofuran solution (0.4% by mass in terms of resin solid content) filtered through a microfilter

[0119] <Acid value of solid content> The solid acid value (mgKOH / g) of a resin having a polymerizable unsaturated group ((meth)acrylate resin) is the number of milligrams of potassium hydroxide required to neutralize free fatty acid, resin acid, etc. contained in 1 g of a sample, and was calculated according to the following procedures 1) to 4) shown in JIS K0070-1992, except that a toluene / methanol mixed solution (volume ratio 1:1) was used as the solvent instead of a diethyl ether / ethanol mixed solution. 1) The reagents are as follows: 0.1 mol / L hydrochloric acid: Based on JIS K8001 4.5 (5.5) [0.1 mol / L hydrochloric acid (3.646 g HCl / L)]. · 0.1 mol / L potassium hydroxide ethanol solution: Dissolve 7 g of potassium hydroxide specified in JIS K8574 in 5 mL of water, add ethanol (95) specified in JIS K8102 to make 1 L, block out carbon dioxide, leave for 2-3 days, then remove the supernatant or filter and store in an alkali-resistant bottle. For standardization, use a volumetric pipette to transfer 25 mL of 0.1 mol / L hydrochloric acid into an Erlenmeyer flask, add phenolphthalein solution, and titrate with 0.1 mol / L potassium hydroxide ethanol solution to determine the factor from the amount required for neutralization. Phenolphthalein solution: According to JIS K8001 4.3 (indicator). Solvent: A mixture of diethyl ether (as specified in JIS K8103) and ethanol (99.5) (as specified in JIS K8101) in a volume ratio of 1:1 or 2:1. Just before use, add a few drops of phenolphthalein solution as an indicator and neutralize with 0.1 mol / L potassium hydroxide ethanol solution. 2) Equipment and toolsThe equipment and tools shall be as follows: 300mL Erlenmeyer flask Burette 25mL Water bath or hot plate 3) The operation is carried out as follows: -Weigh out an appropriate amount of sample into an Erlenmeyer flask. Add 100 mL of solvent and a few drops of phenolphthalein solution as an indicator, and shake thoroughly in a water bath until the sample is completely dissolved. Titrate with 0.1 mol / L potassium hydroxide ethanol solution, and the endpoint is when the indicator turns pale red for 30 seconds. 4) The acid value is calculated by the following formula. A = (B × f × 5.611) / S Where: A: Acid value (mgKOH / g) B: Amount of 0.1 mol / L potassium hydroxide ethanol solution used in titration (mL) f: Factor of 0.1 mol / L potassium hydroxide ethanol solution S: mass of sample (g) 5.611: Formula weight of potassium hydroxide 56.11 x 1 / 10

[0120] <Polymerizable unsaturated group equivalent> For the resins ((meth)acrylate resins) having a polymerizable unsaturated group in the examples, the polymerizable unsaturated group equivalent (g / equivalent) was calculated using the following formula. Polymerizable unsaturated group equivalent=(total mass of solid resin having polymerizable unsaturated group) / {(number of moles of compound having polymerizable unsaturated group)×(number of polymerizable unsaturated groups per compound molecule)}

[0121] <Viscosity measurement> The viscosity (mPa·s) at 40°C was measured using an E-type viscometer (TV-100EH, manufactured by Toki Sangyo Co., Ltd.).

[0122] (Example 1: Production of Resin (1) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 66.7 parts by mass of diethylene glycol monoethyl ether acetate, and the temperature was raised to 120° C. under a nitrogen atmosphere. Next, dripping A (temperature 25° C.) in which 72 parts by mass of glycidyl methacrylate (methoquinone content 100 ppm), 18 parts by mass of methyl methacrylate (hydroquinone content 100 ppm), 10 parts by mass of benzyl methacrylate (methoquinone content 200 ppm), and 40.6 parts by mass of diethylene glycol monoethyl ether acetate were mixed in advance, and dripping B (temperature 25° C.) in which 15 parts by mass of diethylene glycol monoethyl ether acetate and 5 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by NOF Corporation) were mixed in advance was dropped from separate dropping funnels over a period of 3 hours. The mixture was kept at 120°C for 4 hours to obtain acrylic copolymer (A1) (amount of polymerization inhibitor relative to the solid content of acrylic copolymer (A1) was 110 ppm). Next, 0.5 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 36.5 parts by mass of acrylic acid, and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.3 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.5 L / min. The unit power was 2 kW / m 3 The esterification reaction was carried out at 120°C for 10 hours while stirring at 40°C. The oxygen concentration in the reaction system was in the range of 7.8-8.0% by mass. The E-type viscosity at 40°C, the end point of the reaction, was 500 mPa·s. Next, 38.3 parts by mass of hexahydroisobenzofuran-1,3-dione (hexahydrophthalic anhydride) was added, and the reaction was carried out at 110°C for 3 hours to obtain the intended resin ((meth)acrylate resin) (1) having a polymerizable unsaturated group. The non-volatile content of this resin (1) having a polymerizable unsaturated group was 58.6% by mass, the solid acid value was 81 mgKOH / g, the weight average molecular weight (Mw) was 22,550, and the polymerizable unsaturated group equivalent was 345 g / equivalent.

[0123] (Example 2: Production of Resin (2) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 66.7 parts by mass of diethylene glycol monoethyl ether acetate, and the temperature was raised to 120°C under a nitrogen atmosphere. Next, a mixture of 72 parts by mass of glycidyl methacrylate (100 ppm methoquinone content), 28 parts by mass of methyl methacrylate (100 ppm hydroquinone content), and 40.6 parts by mass of diethylene glycol monoethyl ether acetate (25°C temperature) and a mixture of 15 parts by mass of diethylene glycol monoethyl ether acetate and 5 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by Nippon Oil & Fats Co., Ltd.) were dropped from separate dropping funnels over a period of 3 hours. The mixture was held at 120°C for 4 hours to obtain an acrylic copolymer (A2) (amount of polymerization inhibitor relative to the solid content of the acrylic copolymer (A2) was 100 ppm). Next, 0.5 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 36.5 parts by mass of acrylic acid, and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.3 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.5 L / min. The unit power was 2 kW / m 3 The esterification reaction was carried out at 120°C for 10 hours while stirring at 40°C. The oxygen concentration in the reaction system was in the range of 7.8-8.0% by mass. The E-type viscosity at 40°C, the end point of the reaction, was 460 mPa·s. Next, 38.3 parts by mass of hexahydroisobenzofuran-1,3-dione was added, and the reaction was carried out at 110°C for 3 hours to obtain the desired resin ((meth)acrylate resin) (2) having a polymerizable unsaturated group. The non-volatile content of this resin (2) having a polymerizable unsaturated group was 58.6% by mass, the solid acid value was 82 mgKOH / g, the weight average molecular weight (Mw) was 21,860, and the polymerizable unsaturated group equivalent was 345 g / equivalent.

[0124] (Example 3: Production of Resin (3) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 159 parts by mass of dipropylene glycol monoethyl ether, and the temperature was raised to 120°C under a nitrogen atmosphere. Next, a mixture of 65 parts by mass of methacrylic acid (hydroquinone content 200 ppm), 35 parts by mass of methyl methacrylate (hydroquinone content 100 ppm), and 32 parts by mass of dipropylene glycol monoethyl ether (temperature 25°C) and a mixture of 12 parts by mass of dipropylene glycol monoethyl ether and 4 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by NOF Corporation) were dropped from separate dropping funnels over a period of 3 hours. The mixture was held at 120°C for 4 hours to obtain an acrylic copolymer (A3) (amount of polymerization inhibitor relative to the solid content of the acrylic copolymer (A3) was 170 ppm). Next, 0.2 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 113.5 parts by mass of 2,3-epoxycyclohexylmethylacrylate, and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.3 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.5 L / min. The unit power was 2 kW / m 3 The esterification reaction was carried out at 110°C for 15 hours while stirring at 40°C. The oxygen concentration in the reaction system was in the range of 7.8-8.0% by mass. The E-type viscosity at 40°C, the end point of the reaction, was 350 mPa·s. Next, 28 parts by mass of dipropylene glycol monoethyl ether was added and stirred to obtain the desired resin (3) having a polymerizable unsaturated group. The non-volatile content of this resin ((meth)acrylate resin) (3) having a polymerizable unsaturated group was 47.9% by mass, the solid acid value was 59 mgKOH / g, the weight average molecular weight (Mw) was 18,160, and the polymerizable unsaturated group equivalent was 380 g / equivalent.

[0125] (Example 4: Production of Resin (4) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 66.7 parts by mass of dipropylene glycol monoethyl ether, and the temperature was raised to 120° C. under a nitrogen atmosphere. Next, dripping A (temperature of 25° C.) in which 60 parts by mass of methacrylic acid (hydroquinone content 200 ppm), 30 parts by mass of methyl methacrylate (hydroquinone content 100 ppm), 10 parts by mass of benzyl methacrylate (methoquinone content 200 ppm), and 68.3 parts by mass of dipropylene glycol monoethyl ether were mixed in advance, and dripping B (temperature of 25° C.) in which 15 parts by mass of dipropylene glycol monoethyl ether and 5 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by NOF Corporation) were mixed in advance, were dropped from separate dropping funnels over a period of 3 hours. The mixture was kept at 120°C for 4 hours to obtain acrylic copolymer (A4) (amount of polymerization inhibitor relative to the solid content of acrylic copolymer (A4) was 170 ppm). Next, 0.5 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 65.4 parts by mass of glycidyl methacrylate (methoquinone content 100 ppm), and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.3 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.5 L / min. The unit power was 2 kW / m 3 The mixture was reacted at 110°C for 14 hours while stirring at 40°C, to obtain the desired resin (4) having polymerizable unsaturated groups. The oxygen concentration in the reaction system was in the range of 7.8-8.0% by mass. The non-volatile content of this resin ((meth)acrylate resin) (4) having polymerizable unsaturated groups was 52.2% by mass, the solid acid value was 82 mgKOH / g, the weight-average molecular weight (Mw) was 48,540, the polymerizable unsaturated group equivalent was 359 g / equivalent, and the E-type viscosity at the reaction end point of 40°C was 610 mPa s.

[0126] (Example 5: Production of Resin (5) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 66.7 parts by mass of dipropylene glycol monoethyl ether, and the temperature was raised to 120°C under a nitrogen atmosphere. Next, a mixture of 60 parts by mass of methacrylic acid (hydroquinone content 200 ppm), 40 parts by mass of methyl methacrylate (hydroquinone content 100 ppm), and 68.3 parts by mass of dipropylene glycol monoethyl ether (temperature 25°C) and a mixture of 15 parts by mass of dipropylene glycol monoethyl ether and 5 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by NOF Corporation) was dropped from separate dropping funnels over a period of 3 hours. The mixture was held at 120°C for 4 hours to obtain an acrylic copolymer (A5) (amount of polymerization inhibitor relative to the solid content of the acrylic copolymer (A5) was 160 ppm). Next, 0.5 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 65.4 parts by mass of glycidyl methacrylate (methoquinone content 100 ppm), and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.3 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.5 L / min. The unit power was 2 kW / m 3 The mixture was reacted at 110°C for 14 hours while stirring at 40°C, to obtain the desired resin having polymerizable unsaturated groups ((meth)acrylate resin) (5). The oxygen concentration in the reaction system was in the range of 7.8-8.0% by mass. The non-volatile content of this resin having polymerizable unsaturated groups (5) was 52.2% by mass, the acid value of the solid content was 81 mgKOH / g, the weight-average molecular weight (Mw) was 47,310, the polymerizable unsaturated group equivalent was 359 g / equivalent, and the E-type viscosity at the reaction end point of 40°C was 610 mPa s.

[0127] (Comparative Example 1: Production of Resin (C1) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 66.7 parts by mass of diethylene glycol monoethyl ether acetate, and the temperature was raised to 120°C under a nitrogen atmosphere. Next, 72 parts by mass of glycidyl methacrylate (methoquinone content 100 ppm) and 28 parts by mass of methyl methacrylate (hydroquinone content 100 ppm) were mixed in advance to form a drop A (temperature of 25°C), and 5 parts by mass of diethylene glycol monoethyl ether acetate and 5 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by Nippon Oil & Fats Co., Ltd.) were mixed in advance to form a drop B (temperature of 25°C) and dropped from separate dropping funnels over a period of 3 hours. The mixture was held at 120°C for 4 hours to obtain an acrylic copolymer (c1) (amount of polymerization inhibitor relative to the solid content of the acrylic copolymer (c1) was 100 ppm). Next, 0.5 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 36.5 parts by mass of acrylic acid, and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.3 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.5 L / min. The unit power was 0.1 kW / m 3 The mixture was reacted at 120°C for 10 hours while stirring at 40°C. The oxygen concentration in the reaction system was in the range of 7.8-8.0% by mass. The E-type viscosity at 40°C, the end point of the reaction, was 2800 mPa·s. Next, 38.3 parts by mass of hexahydroisobenzofuran-1,3-dione was added, and the mixture was reacted at 110°C for 5 hours. 103.1 parts by mass of diethylene glycol monoethyl ether acetate was added and stirred to obtain the desired resin ((meth)acrylate resin) having a polymerizable unsaturated group (C1). The non-volatile content of this resin (C1) having a polymerizable unsaturated group was 49.8% by mass, and the solid acid value was 81 mgKOH / g.

[0128] (Comparative Example 2: Production of Resin (C2) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 66.7 parts by mass of diethylene glycol monoethyl ether acetate, and the temperature was raised to 120°C under a nitrogen atmosphere. Next, 72 parts by mass of glycidyl methacrylate (methoquinone content 600 ppm), 28 parts by mass of methyl methacrylate (hydroquinone content 500 ppm), 55.6 parts by mass of diethylene glycol monoethyl ether acetate, and 5 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by Nippon Oil & Fats Co., Ltd.) were mixed in advance and dropped over 3 hours (the temperature of the dropped liquid was 25°C). The mixture was held at 120°C for 4 hours to obtain an acrylic copolymer (c2) (amount of polymerization inhibitor relative to the solid content of the acrylic copolymer (c2) was 570 ppm). Next, 0.5 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 36.5 parts by mass of acrylic acid, and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.3 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.5 L / min. The unit power was 2 kW / m 3 The esterification reaction was carried out at 120°C for 10 hours while stirring at 40°C. The oxygen concentration in the reaction system was in the range of 7.8-8.0% by mass. The E-type viscosity at 40°C, the end point of the reaction, was 620 mPa·s. Next, 38.3 parts by mass of hexahydroisobenzofuran-1,3-dione was added, and the reaction was carried out at 110°C for 5 hours to obtain the desired resin having a polymerizable unsaturated group ((meth)acrylate resin) (C2). The non-volatile content of this resin having a polymerizable unsaturated group (C2) was 58.6% by mass, and the acid value of the solid content was 80 mgKOH / g.

[0129] (Comparative Example 3: Production of Resin (C3) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 66.7 parts by mass of diethylene glycol monoethyl ether acetate, and the temperature was raised to 120°C under a nitrogen atmosphere. Next, 72 parts by mass of glycidyl methacrylate (methoquinone content 100 ppm), 28 parts by mass of methyl methacrylate (hydroquinone content 100 ppm), 55.6 parts by mass of diethylene glycol monoethyl ether acetate, and 5 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by Nippon Oil & Fats Co., Ltd.) were mixed in advance and dropped over 3 hours (temperature of the dropped liquid was 25°C). The mixture was held at 120°C for 4 hours to obtain an acrylic copolymer (c3) (amount of polymerization inhibitor relative to the solid content of the acrylic copolymer (c3) was 170 ppm). Next, 0.5 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 36.5 parts by mass of acrylic acid, and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.3 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.5 L / min. The unit power was 2 kW / m 3 The esterification reaction was carried out at 120°C for 10 hours while stirring at 40°C. The oxygen concentration in the reaction system was in the range of 7.8-8.0% by mass. The E-type viscosity at 40°C, the end point of the reaction, was 560 mPa·s. Next, 38.3 parts by mass of hexahydroisobenzofuran-1,3-dione was added, and the reaction was carried out at 110°C for 5 hours to obtain the desired resin having a polymerizable unsaturated group ((meth)acrylate resin) (C3). The non-volatile content of this resin having a polymerizable unsaturated group (C3) was 58.6% by mass, and the solid content acid value was 82 mgKOH / g.

[0130] (Comparative Example 4: Production of Resin (C4) Having Polymerizable Unsaturated Group) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 66.7 parts by mass of diethylene glycol monoethyl ether acetate, and the temperature was raised to 120°C under a nitrogen atmosphere. Next, 72 parts by mass of glycidyl methacrylate (methoquinone content 100 ppm), 28 parts by mass of methyl methacrylate (hydroquinone content 100 ppm), 55.6 parts by mass of diethylene glycol monoethyl ether acetate, and 5 parts by mass of (2-ethylhexanoyl)(tert-butyl)peroxide ("Perbutyl O" manufactured by Nippon Oil & Fats Co., Ltd.) were mixed in advance and added dropwise over 3 hours. The mixture was held at 120°C for 4 hours to obtain an acrylic copolymer (c4) (amount of polymerization inhibitor relative to the solid content of the acrylic copolymer (c4) was 100 ppm). Next, 0.5 parts by mass of dibutylhydroxytoluene, 0.1 parts by mass of methylhydroquinone, 36.5 parts by mass of acrylic acid, and 0.6 parts by mass of triphenylphosphine were charged, and air was blown in from below the liquid surface at 0.04 L / min using a stainless steel tube with an inner diameter of 0.5 mm, and nitrogen was blown in from above the liquid surface at 0.76 L / min. The unit power was 2 kW / m 3 The esterification reaction was carried out at 120°C for 13 hours while stirring at 40°C. The oxygen concentration in the reaction system was in the range of 1.0-1.2% by mass. The E-type viscosity at 40°C, the end point of the reaction, was 670 mPa·s. Next, 38.3 parts by mass of hexahydroisobenzofuran-1,3-dione was added, and the reaction was carried out at 110°C for 5 hours to obtain the desired resin having a polymerizable unsaturated group ((meth)acrylate resin) (C4). The non-volatile content of this resin having a polymerizable unsaturated group (C4) was 58.6% by mass, and the acid value of the solid content was 81 mgKOH / g.

[0131] (Examples 6 to 10 and Comparative Examples 5 to 8: Preparation of Curable Resin Compositions and Evaluation of Photosensitivity) [Preparation of Curable Resin Composition] Resins (1) to (5), (C1) to (C4) having a polymerizable unsaturated group obtained in Examples 1 to 5 and Comparative Examples 1 to 4, a bisphenol A type epoxy resin (EPICLON 850-S manufactured by DIC Corporation, epoxy equivalent: 188 g / equivalent) as a curing agent, a photopolymerization initiator (Omnirad 907 manufactured by IGM Resins), dipentaerythritol hexaacrylate, 2-ethyl-4-methyl-imidazole, and titanium oxide (CR-93 manufactured by Ishihara Sangyo Kaisha, Ltd.) were mixed in the amounts shown in Table 1 (parts by mass, solid content value for resins having a polymerizable unsaturated group) to obtain curable resin compositions (1) to (5), (C5) to (C8).

[0132] [Method of evaluating light sensitivity] The curable resin composition obtained above was applied to a glass substrate using an applicator to a film thickness of 50 μm, and then dried at 80° C. for 30 minutes. Then, the composition was exposed to 5 kJ / m 2 of a metal halide lamp through a Kodak Step Tablet No. 2. 2 This was developed for 180 seconds in a 1% by weight aqueous solution of sodium carbonate, and the number of remaining steps was used for evaluation. Note that the greater the number of remaining steps, the higher the photosensitivity.

[0133] [Table 1]

[0134] (Examples 11 to 15 and Comparative Examples 9 to 12: Preparation of curable resin compositions and evaluation of heat resistance, heat yellowing resistance, and reflectivity) [Preparation of Curable Resin Composition] Resins (1) to (5), (C1) to (C4) having a polymerizable unsaturated group obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were mixed with a bisphenol A type epoxy resin (EPICLON 850-S manufactured by DIC Corporation, epoxy equivalent: 188 g / equivalent) as a curing agent, and a photopolymerization initiator (Omnirad 907 manufactured by IGM Resins) in the amounts shown in Table 2 (parts by mass, solid content value for resins having a polymerizable unsaturated group) to obtain curable resin compositions (6) to (10), (C9) to (C12).

[0135] [Heat resistance evaluation method] The curable resin composition obtained above was applied to a copper foil (electrolytic copper foil "F2-WS" 18 μm, manufactured by Furukawa Sangyo Kaisha) using an applicator to a thickness of 50 μm, and dried at 80° C. for 30 minutes. Then, a metal halide lamp was used to apply the applied curable resin composition to the copper foil. 2 After irradiating with ultraviolet light of 1000 nm, the coating was heated at 160°C for 1 hour to obtain a cured coating film. The cured coating film was then peeled off from the copper foil to obtain a cured product. A 6 mm x 35 mm test piece was cut out from the cured product, and the temperature at which the change in elastic modulus was maximum was evaluated as the glass transition temperature (Tg) using a viscoelasticity measuring device (DMA: Rheometrics Corp. solid viscoelasticity measuring device "RSAII", tensile method: frequency 1 Hz, heating rate 3°C / min). Note that a higher glass transition temperature indicates better heat resistance.

[0136] [Method for evaluating heat resistance to yellowing] The curable resin composition obtained above was applied to a glass plate using an applicator to a thickness of 50 μm, and dried at 80° C. for 30 minutes. Then, a metal halide lamp was used to apply the applied curable resin composition to the glass plate at 10 kJ / m 2 After irradiating the film with ultraviolet light, it was heated at 160°C for 1 hour to obtain a cured coating film. The resulting cured coating film was heated to 260°C in a hot air circulation drying oven for accelerated aging, and removed after 60 minutes. The color difference ΔE*ab from the unheated cured coating film was measured using a colorimeter ("ZE6000" manufactured by Nippon Denshoku Industries Co., Ltd.). The lower the color difference ΔE*ab, the better the heat yellowing resistance.

[0137] [Reflectivity evaluation method] The curable resin composition obtained above was applied to a glass plate using an applicator to a thickness of 50 μm, and dried at 80° C. for 30 minutes. Then, a metal halide lamp was used to apply the applied curable resin composition to the glass plate at 10 kJ / m 2After irradiating the coating with ultraviolet rays, the coating was heated at 160°C for 1 hour to obtain a cured coating film. The cured coating film obtained was heated to 260°C in a hot air circulation drying oven to accelerate deterioration, and after 60 minutes it was taken out and the reflectance (Y) (%) was measured using a colorimeter "ZE6000" manufactured by Nippon Denshoku Industries Co., Ltd. <After heat resistance test>. Note that a higher reflectance (Y) (%) indicates better reflectivity.

[0138] [Table 2]

[0139] In addition, the parts by mass of the polymerizable unsaturated group-containing resin in Tables 1 and 2 are solid content values.

[0140] Examples 6 to 15 shown in Tables 1 and 2 are examples in which a (meth)acrylate resin produced by the method of the present invention was used. It was confirmed that the (meth)acrylate resin produced by the method of the present invention has excellent photosensitivity in a curable resin composition containing the resin, and excellent heat resistance, heat yellowing resistance, and reflectivity in a cured product obtained from the curable resin composition in a well-balanced manner.

[0141] On the other hand, Comparative Examples 5 and 9 shown in Tables 1 and 2 are examples using a (meth)acrylate resin (Comparative Example 1) that was produced by a method requiring a lower unit power during stirring than the method of the present invention and had a higher viscosity than the specification of the present invention. Comparative Examples 6, 7, 8, 10, 11, and 12 shown in Tables 1 and 2 are examples using a (meth)acrylate resin produced by a method different from the method of the present invention in that a solution in which a polymerization raw material and a polymerization initiator were mixed in advance was dropped into an organic solvent. It was confirmed that the (meth)acrylate resin produced by a method different from the method of the present invention does not have excellent photosensitivity in a curable resin composition containing the resin, and does not have excellent heat resistance, heat yellowing resistance, and reflectivity in a cured product obtained from the curable resin composition.

Claims

1. The following steps: (i) producing a reactive functional group-containing acrylic resin (A1) by separately dropping a liquid (L1) containing a polymerization raw material for the reactive functional group-containing acrylic resin (A1) and a liquid (L2) containing a polymerization initiator into an organic solvent and mixing the liquid (L1) to polymerize the polymerization raw material for the acrylic resin (A1); and (ii) a step of producing a (meth)acrylate resin by reacting the reactive functional group-containing acrylic resin (A1) obtained in the step (i) with a compound (A2) containing a functional group capable of reacting with the reactive functional group and a polymerizable unsaturated group as essential raw materials. A method for producing a (meth)acrylate resin, comprising: the amount of the polymerization inhibitor in the reactive functional group-containing acrylic resin (A1) obtained in the step (i) is 500 ppm or less based on the solid content of the acrylic resin (A1); The reaction of step (ii) is carried out in the presence of a basic catalyst under an atmosphere of an oxygen-containing gas (b1) and an inert gas (b2) with stirring; The oxygen concentration in the reaction system in which step (ii) is carried out is in the range of 2 to 12 mass %, The stirring power per unit volume is 0.2 to 8 kW / m ３ This is done as a range of The viscosity of the obtained (meth)acrylate resin at 40°C is 2,000 mPa s or less. A method for producing a (meth)acrylate resin.

2. The method for producing a (meth)acrylate resin according to claim 1, wherein the acrylic resin (A1) is an epoxy group- or carboxyl group-containing acrylic resin, and the compound (A2) is an unsaturated monobasic acid or an epoxy group-containing (meth)acrylate.

3. The method for producing a (meth)acrylate resin according to claim 2, wherein the acrylic resin (A1) is an epoxy group-containing acrylic resin, and the compound (A2) is an unsaturated monobasic acid.

4. 3. The method for producing a (meth)acrylate resin according to claim 2, wherein the acrylic resin (A1) is a carboxyl group-containing acrylic resin, and the compound (A2) is an epoxy group-containing (meth)acrylate.

5. A method for producing a curable resin composition, comprising a step of mixing a (meth)acrylate resin obtained by the method for producing a (meth)acrylate resin according to any one of claims 1 to 4 with a photopolymerization initiator to obtain a curable resin composition.

6. A method for producing a cured product, comprising a step of curing the curable resin composition obtained by the method for producing a curable resin composition according to claim 5 to obtain a cured product.

7. A method for producing an insulating material, comprising using a cured product obtained by the method according to claim 6.

8. A method for producing a resist member, comprising using a cured product obtained by the method according to claim 6.

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