Photocurable resin composition and cured product

Abstract

Provided is a photocurable resin composition having a high glass transition temperature and excellent adhesiveness. The photocurable resin composition according to an embodiment comprises component (A): α-(unsaturated alkoxyalkyl)acrylate, component (B): alicyclic (meth)acrylate, and component (C): a (meth)acrylamide derivative of a secondary amide and / or a (meth)acrylamide derivative of a tertiary amide. The content of component (B) is 30-60 parts by mass with respect to 100 parts by mass of the total of component (A), component (B), and component (C).

Description

Photocurable resin composition and cured product

[0001] The present invention relates to a photocurable resin composition and a cured product thereof.

[0002] BACKGROUND ART Curable resin compositions have conventionally been used, for example, as coating agents for protecting the surfaces of printed circuit boards and adhesives for adhering components onto printed circuit boards.

[0003] As a technique relating to a curable resin composition, for example, Patent Document 1 discloses a curable resin composition containing α-(unsaturated alkoxyalkyl)acrylic acid or an ester thereof, a bifunctional radically polymerizable oligomer, rubber particles, and a radically polymerizable initiator.

[0004] Japanese Patent Application Laid-Open No. 2022-135918

[0005] Among the curable resin compositions described above, photocurable resin compositions that are cured by light such as ultraviolet light can be cured in a short time without the application of heat, and are therefore considered to be useful as coating agents or adhesives for printed circuit boards. However, coating agents and adhesives for printed circuit boards are required not only to be curable in a short time, but also to have excellent adhesion to the printed circuit board and, from the viewpoint of heat resistance, to have a high glass transition temperature.

[0006] The curable resin composition of Patent Document 1 contains an α-(unsaturated alkoxyalkyl)acrylic acid ester. However, Patent Document 1 aims to provide a curable resin composition suitable for stereolithography that has low viscosity and excellent handleability during modeling, as well as impact resistance and a high elastic modulus of the cured product, but does not provide sufficient properties in terms of glass transition temperature and adhesion to printed circuit boards.

[0007] An object of an embodiment of the present invention is to provide a photocurable resin composition having a high glass transition temperature and excellent adhesiveness.

[0008] The present invention includes the following embodiments: [1] A photocurable resin composition comprising: (A) component: an α-(unsaturated alkoxyalkyl)acrylic acid ester; (B) component: an alicyclic (meth)acrylate; and (C) component: a (meth)acrylamide derivative of a secondary amide and / or a (meth)acrylamide derivative of a tertiary amide, wherein the content of the (B) component is 30 to 60 parts by mass per 100 parts by mass of the total of the (A), (B), and (C) components.

[0009] [2] The photocurable resin composition according to [1], further comprising silica.

[0010] [3] The α-(unsaturated alkoxyalkyl)acrylic acid ester contains a compound represented by the following general formula (1): In the formula, R １ represents a monovalent organic group having 1 to 30 carbon atoms, and R ２ represents a methylene group which may have an alkyl group having 1 to 4 carbon atoms as a substituent, and R ３ and R ４ one of which represents a methylene group which may have an alkyl group having 1 to 4 carbon atoms as a substituent, and the other represents an oxygen atom; R ５ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an ester group.

[0011] [4] The photocurable resin composition according to any one of [1] to [3], wherein the molecular weight of the alicyclic (meth)acrylate is 500 or less.

[0012] [5] The photocurable resin composition according to any one of [1] to [4], wherein the alicyclic (meth)acrylate includes an alicyclic di(meth)acrylate.

[0013] [6] The photocurable resin composition according to any one of [1] to [5], wherein the component (C) contains a (meth)acrylamide derivative of the tertiary amide.

[0014] [7] The photocurable resin composition according to any one of [1] to [6], wherein the content of the component (A) is 5 to 50 parts by mass relative to a total of 100 parts by mass of the component (A), the component (B), and the component (C).

[0015] [8] The photocurable resin composition according to any one of [1] to [7], which is used by applying it to a printed circuit board.

[0016] [9] A cured product obtained by curing the photocurable resin composition according to any one of [1] to [8].

[0017]

[10] Use of the photocurable resin composition according to any one of [1] to [8] for coating a printed circuit board.

[0018] The photocurable resin composition according to the embodiment of the present invention has a high glass transition temperature and excellent adhesiveness.

[0019] The photocurable resin composition according to this embodiment contains the following components (A) to (C): Component (A): α-(unsaturated alkoxyalkyl) acrylic acid ester Component (B): alicyclic (meth)acrylate Component (C): (meth)acrylamide derivative which is a secondary amide and / or tertiary amide

[0020] In this specification, "(meth)acrylate" means acrylate and / or methacrylate. Similarly, "(meth)acrylamide" means acrylamide and / or methacrylamide. The same applies to other terms such as "(meth)acryloyl".

[0021] [Component (A)] Component (A) is an α-(unsaturated alkoxyalkyl) acrylate ester. When the photocurable resin composition contains an α-(unsaturated alkoxyalkyl) acrylate ester, it is possible to improve adhesion. The α-(unsaturated alkoxyalkyl) acrylate ester is an acrylic ester in which an alkoxyalkyl group having an organic group containing an unsaturated group is substituted at the α-position. Here, the unsaturated group is a vinyl group (-CH=CH ２ ), vinylidene group (C=CH ２ ) is preferred.

[0022] As the α-(unsaturated alkoxyalkyl) acrylate, a compound represented by the following general formula (1) is preferably used.

[0023] In formula (1), R１ represents a monovalent organic group having 1 to 30 carbon atoms. The organic group is preferably a monovalent hydrocarbon group composed of hydrocarbons. The organic group may be an alkoxy-substituted chain hydrocarbon group in which one or more hydrogen atoms of a chain saturated hydrocarbon group have been substituted with an alkoxy group, or may be a hydrocarbon group in which one or more hydrogen atoms have been substituted with a hydroxy group, a halogen atom, or the like.

[0024] The monovalent hydrocarbon group may be saturated or unsaturated, and may be a linear or branched chain, or may be cyclic (alicyclic, aromatic). Preferably, the hydrocarbon group is a chain saturated hydrocarbon group having 1 to 20 carbon atoms, a chain unsaturated hydrocarbon group having 3 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms, and more preferably a chain saturated hydrocarbon group having 1 to 10 carbon atoms. Examples of the chain saturated hydrocarbon group, i.e., an alkyl group, include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an n-pentyl group, a neopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, a sec-hexyl group, an n-heptyl group, an n-octyl group, and a 2-ethylhexyl group.

[0025] R ２ represents a methylene group which may have an alkyl group having 1 to 4 carbon atoms as a substituent. The alkyl group as a substituent may substitute either or both of the two hydrogen atoms of the methylene group. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. R ２ is preferably a methylene group which may have an alkyl group having 1 or 2 carbon atoms as a substituent, and more preferably a methylene group.

[0026] R ３ and R ４represents a methylene group, one of which may have an alkyl group having 1 to 4 carbon atoms as a substituent, and the other represents an oxygen atom. The alkyl group as a substituent may substitute either or both of the two hydrogen atoms of the methylene group. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. Preferably, R ４ represents a methylene group which may have an alkyl group having 1 to 4 carbon atoms as a substituent, and R ３ represents an oxygen atom. More preferably, R ４ represents a methylene group, and R ３ represents an oxygen atom.

[0027] R ５ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an ester group. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. An ester group is represented by -COOR ６ where R ６ is preferably a monovalent organic group having 1 to 30 carbon atoms. ６ For details of the monovalent organic group represented by the formula １ It is the same as R ５ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom.

[0028] Specific examples of the α-(unsaturated alkoxyalkyl)acrylic acid ester include methyl α-allyloxymethylacrylate, ethyl α-allyloxymethylacrylate, n-propyl α-allyloxymethylacrylate, isopropyl α-allyloxymethylacrylate, n-butyl α-allyloxymethylacrylate, n-pentyl α-allyloxymethylacrylate, neopentyl α-allyloxymethylacrylate, sec-pentyl α-allyloxymethylacrylate, tert-pentyl α-allyloxymethylacrylate, and α-allyloxymethylacrylate. α-Allyloxymethyl acrylate esters such as n-hexyl acrylate, n-hexyl α-allyloxymethyl acrylate, sec-hexyl α-allyloxymethyl acrylate, n-heptyl α-allyloxymethyl acrylate, n-octyl α-allyloxymethyl acrylate, and 2-ethylhexyl α-allyloxymethyl acrylate; methyl α-methallyloxymethyl acrylate, ethyl α-methallyloxymethyl acrylate, n-propyl α-methallyloxymethyl acrylate, isopropyl α-methallyloxymethyl acrylate, n-butyl α-methallyloxymethyl acrylate; α-Methallyloxymethyl acrylate esters such as n-pentyl methallyloxymethyl acrylate, neopentyl α-methallyloxymethyl acrylate, sec-pentyl α-methallyloxymethyl acrylate, tert-pentyl α-methallyloxymethyl acrylate, n-hexyl α-methallyloxymethyl acrylate, sec-hexyl α-methallyloxymethyl acrylate, n-heptyl α-methallyloxymethyl acrylate, n-octyl α-methallyloxymethyl acrylate, and 2-ethylhexyl α-methallyloxymethyl acrylate; dimethallyloxymethyl acrylates such as n-pentyl α-methallyloxymethyl acrylate, neopentyl α-methallyloxymethyl acrylate, sec-pentyl α-methallyloxymethyl acrylate, tert-pentyl α-methallyloxymethyl acrylate, n-hexyl α-methallyloxymethyl acrylate, n-octyl α-methallyloxymethyl acrylate, and 2-ethylhexyl α-methallyloxymethyl acrylate; Methyl-2,2'-[oxybis(methylene)]bis-2-propenoate, diethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, di(n-propyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(isopropyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(n-butyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(n-pentyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(tert-pentyl)-2,Examples of such compounds include dialkyl-2,2'-[oxybis(methylene)]bis-2-propenoates such as 2'-[oxybis(methylene)]bis-2-propenoate and di(2-ethylhexyl)-2,2'-[oxybis(methylene)]bis-2-propenoate. These compounds may be used alone or in combination of two or more.

[0029] The α-(unsaturated alkoxyalkyl)acrylate ester is preferably a compound that polymerizes while forming a 5- or 6-membered cyclic ether. Specifically, in one embodiment, the α-(unsaturated alkoxyalkyl)acrylate ester preferably includes an α-allyloxymethylacrylate ester, more preferably includes an alkyl α-allyloxymethylacrylate, and even more preferably includes methyl α-allyloxymethylacrylate.

[0030] The amount of the compound represented by formula (1) (preferably an α-allyloxymethyl acrylic acid ester, more preferably an alkyl α-allyloxymethyl acrylate, more preferably methyl α-allyloxymethyl acrylate) is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and may be 100% by mass, based on 100% by mass of the α-(unsaturated alkoxyalkyl)acrylic acid ester, which is component (A).

[0031] The content of component (A) is preferably 5 to 50 parts by mass relative to 100 parts by mass of the total of components (A), (B), and (C). By having a content of component (A) of 5 parts by mass or more, the effect of improving adhesiveness can be enhanced. The content of component (A) is more preferably 10 to 40 parts by mass, more preferably 15 to 35 parts by mass, and even more preferably 20 to 30 parts by mass.

[0032] [Component (B)] Component (B) is an alicyclic (meth)acrylate. By including an alicyclic (meth)acrylate in the photocurable resin composition, the glass transition temperature of the cured product can be increased. The alicyclic (meth)acrylate is a compound containing an alicyclic hydrocarbon group and a (meth)acryloyloxy group in the molecule, and may be a monofunctional alicyclic (meth)acrylate having one (meth)acryloyloxy group, or a polyfunctional alicyclic (meth)acrylate having two or more (meth)acryloyloxy groups.

[0033] The alicyclic hydrocarbon group may be a monocyclic hydrocarbon group, a bicyclic or tricyclic or more ring bridged cyclic hydrocarbon group, or a ring assembly hydrocarbon group. The (meth)acryloyloxy group is preferably bonded to the alicyclic hydrocarbon group directly or via a methylene group.

[0034] Examples of monofunctional alicyclic (meth)acrylates include cyclohexyl (meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, 3,5-dihydroxy-1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, 2-isopropyl-2-adamantyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, etc. These may be used alone or in combination of two or more.

[0035] Examples of polyfunctional alicyclic (meth)acrylates include tricyclodecane dimethanol di(meth)acrylate, cyclohexane dimethanol di(meth)acrylate, hydrogenated bisphenol A dimethacrylate, etc. These may be used alone or in combination of two or more.

[0036] The alicyclic (meth)acrylate is preferably an alicyclic di(meth)acrylate having two (meth)acryloyloxy groups, more preferably tricyclodecane dimethanol di(meth)acrylate. The amount of the alicyclic di(meth)acrylate (more preferably tricyclodecane dimethanol di(meth)acrylate) is preferably 60% by mass or more, more preferably 80% by mass or more, or even 90% by mass or more, based on 100% by mass of the alicyclic (meth)acrylate of component (B), and may be 100% by mass.

[0037] It is preferable to use an alicyclic (meth)acrylate having a molecular weight of 500 or less. By using an alicyclic (meth)acrylate with such a small molecular weight, the glass transition temperature of the cured product can be further increased. The molecular weight of the alicyclic (meth)acrylate is more preferably 400 or less. The lower limit of the molecular weight of the alicyclic (meth)acrylate is not particularly limited, and may be, for example, 100.

[0038] The content of component (B) is 30 to 60 parts by mass, relative to 100 parts by mass of the total of components (A), (B), and (C). When the content of component (B) is 30 parts by mass or more, the glass transition temperature of the cured product can be increased and the linear expansion coefficient can be reduced. When the content of component (B) is 60 parts by mass or less, the adhesiveness can be improved. The content of component (B) is more preferably 35 to 60 parts by mass, more preferably 40 to 55 parts by mass, and even more preferably 45 to 55 parts by mass.

[0039] [Component (C)] Component (C) is a (meth)acrylamide derivative of a secondary amide and / or a (meth)acrylamide derivative of a tertiary amide. By including the (meth)acrylamide derivative in the photocurable resin composition, adhesion can be improved. The (meth)acrylamide derivative is a monofunctional (meth)acrylamide compound having one (meth)acryloyl group in the molecule, and may be a secondary amide in which the number of hydrogen atoms bonded to the nitrogen atom of the amide bond is one, a tertiary amide in which the number of hydrogen atoms is zero, or a combination of both.

[0040] Examples of (meth)acrylamide derivatives include secondary amides such as N-methyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-tert-butyl(meth)acrylamide, N-phenyl(meth)acrylamide, N-methylol(meth)acrylamide, N-(2-hydroxyethyl)acrylamide, and N-[3-(dimethylamino)propyl]acrylamide, and tertiary amides such as (meth)acryloylmorpholine, N-(meth)acryloylpiperidine, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, and N,N-diphenyl(meth)acrylamide. Any of these may be used alone, or two or more may be used in combination.

[0041] As the (meth)acrylamide derivative of component (C), it is preferable to use a tertiary amide because it can increase the glass transition temperature, and more preferably to use at least one tertiary amide X selected from the group consisting of (meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and N,N-dialkyl(meth)acrylamide. The amount of the (meth)acrylamide derivative of the tertiary amide (more preferably the tertiary amide X) is preferably 60% by mass or more, preferably 80% by mass or more, preferably 90% by mass or more, and may be 100% by mass, based on 100% by mass of the (meth)acrylamide derivative of component (C).

[0042] The content of component (C) is preferably 5 to 50 parts by mass relative to 100 parts by mass of the total of components (A), (B), and (C). By having a content of component (C) of 5 parts by mass or more, the effect of improving adhesiveness can be enhanced. The content of component (C) is more preferably 10 to 40 parts by mass, more preferably 15 to 35 parts by mass, and even more preferably 20 to 30 parts by mass.

[0043] [Component (D)] The photocurable resin composition according to this embodiment may further contain silica as component (D). By containing silica, the linear expansion coefficient of the cured product can be reduced. The silica is not particularly limited, and various silica powders such as wet silica and dry silica can be used.

[0044] The silica to be used may be one that has been surface-treated with a silane coupling agent, one that has not been surface-treated, or a combination of one that has been surface-treated and one that has not been surface-treated.

[0045] When silica is added, the content thereof is not particularly limited, and may be 200 to 800 parts by mass, 300 to 700 parts by mass, or 400 to 600 parts by mass relative to 100 parts by mass of the total of the (A), (B), and (C) components.

[0046] [Other Components] In the photocurable resin composition according to this embodiment, the resin component may be composed solely of the above components (A) to (C), but may also contain a compound having a radically polymerizable functional group other than components (A) to (C) (hereinafter referred to as a radically polymerizable compound) as long as the effects of this embodiment are not impaired. Examples of such other radically polymerizable functional groups include ethylenically unsaturated groups. Specific examples of ethylenically unsaturated groups include (meth)acryloyl groups and vinyl groups.

[0047] Examples of radical polymerizable compounds having a (meth)acryloyl group include acrylamide compounds and (meth)acrylate compounds, such as aliphatic (meth)acrylates, aromatic (meth)acrylates, polyethylene glycol (meth)acrylates, oxetane (meth)acrylates, urethane (meth)acrylates, epoxy (meth)acrylates, ester (meth)acrylates, and acrylic (meth)acrylates.

[0048] Examples of the radical polymerizable compound having an ethylenically unsaturated group other than a (meth)acryloyl group include styrene derivatives such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and salts thereof; maleimides such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; vinyl cyanide compounds such as (meth)acrylonitrile; and N-vinyl compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylimidazole, N-vinylmorpholine, and N-vinylacetamide.

[0049] The amount of the other radical polymerizable compound is not particularly limited, but is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the total of the (A), (B), and (C) components.

[0050] The photocurable resin composition according to this embodiment may contain a photopolymerization initiator. Examples of the photopolymerization initiator include benzophenone, 4-methylbenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-4'-methylthio-2-morpholinopropiophenone, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, benzyl dimethyl ketal, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, benzoin isopropyl ether, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate, and (2,4,6-trimethylbenzoyl)bis(p-tolyl)phosphine oxide. These may be used alone or in combination of two or more.

[0051] The content of the photopolymerization initiator is not particularly limited, and may be, for example, 0.1 to 10 parts by mass or 0.5 to 5 parts by mass relative to 100 parts by mass of the total of the (A), (B), and (C) components.

[0052] The photocurable resin composition according to this embodiment may contain additives as optional components within a range that does not impair the effects of this embodiment. Examples of additives include colorants such as pigments, thermal radical polymerization initiators, sensitizers, chain transfer agents, thickeners, antioxidants, polymerization inhibitors, fluorescent agents, moisture absorbents, rust inhibitors, preservatives, surface conditioners, and fillers.

[0053] The photocurable resin composition according to the present embodiment can be cured by irradiation with light. Here, light refers to, for example, light rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, electromagnetic waves such as X-rays and gamma rays, and active energy rays such as electron beams, proton beams, and neutron beams.

[0054] [Uses] The photocurable resin composition according to this embodiment can be cured by irradiation with light such as ultraviolet light, allowing for rapid curing. Furthermore, the cured product exhibits excellent adhesion to printed circuit boards and has a high glass transition temperature, resulting in excellent heat resistance. Therefore, it is suitable for applications in which it is applied to printed circuit boards. Specifically, it is suitable for use as a coating agent for protecting the surface of printed circuit boards or as an adhesive for adhering components to printed circuit boards. It can be applied to a printed circuit board and cured by irradiation with light such as ultraviolet light. This results in a cured product formed by curing the photocurable resin composition on the printed circuit board.

[0055] The printed circuit board to be coated is not particularly limited, and examples thereof include glass epoxy boards, glass composite boards, paper phenol boards, and paper epoxy boards.

[0056] Examples will be described in detail below along with comparative examples, but the present invention is not limited to these examples.

[0057] Details of the raw materials used in the examples and comparative examples are as follows: [Component (A)] A-1: ​​methyl α-allyloxymethylacrylate, "AOMA" manufactured by Nippon Shokubai Co., Ltd., in which R １ is a methyl group, R ２ is a methylene group, R ３ is an oxygen atom, R ４ is a methylene group, R ５ represents a hydrogen atom.

[0058] [Component (B)] B-1: Tricyclodecane dimethanol diacrylate (TCDDA), "IRR 214-K" manufactured by Daicel Allnex Corporation, a compound represented by the following formula:

[0059] [Component (C)] C-1: Acryloylmorpholine, "ACMO" manufactured by KJ Chemicals Co., Ltd. C-2: N,N-dimethylacrylamide, "DMAA" manufactured by KJ Chemicals Co., Ltd. C-3: N,N-diethylacrylamide, "DEAA" manufactured by KJ Chemicals Co., Ltd. C-4: N-(2-hydroxyethyl)acrylamide, "HEAA" manufactured by KJ Chemicals Co., Ltd. C-5: N-isopropylacrylamide, "NIPAM" manufactured by KJ Chemicals Co., Ltd.

[0060] [Component (D)] D-1: Silica, "HS-208" manufactured by Nippon Steel Chemical & Material Co., Ltd.

[0061] [Component (E)] E-1: Photopolymerization initiator, "Omnirad TPO-N" manufactured by IGMresins

[0062] [Preparation of Photocurable Resin Composition] According to the formulations (parts by mass) shown in Tables 1 to 3 below, predetermined amounts of components (A), (B), (C), and (E) were placed in a 200 mL disposable cup so that the total amount was 20.6 g, and mixed in a mixer ("Awatori Rentaro", manufactured by Thinky Corporation) at 2000 rpm for 1 minute. Thereafter, a predetermined amount of component (D) was added, and the mixture was mixed by hand using a spatula. After the liquid had thoroughly dispersed the filler (component (D)), the mixture was mixed in the mixer at 2000 rpm for 1 minute, dispersing and degassing, to prepare a photocurable resin composition.

[0063] [Evaluation] The resulting photocurable resin compositions were evaluated for adhesiveness, glass transition temperature, coefficient of linear expansion, and dispersibility using the following methods.

[0064] (Adhesion) The adhesive strength (MPa) was evaluated using a universal testing machine with reference to the pudding cup method. Specifically, the photocurable resin composition was cured on a glass epoxy substrate using an LED-UV irradiator to form a cylindrical shape with a diameter of 6 mm and a height of 2 mm. Using an Autograph (precision universal testing machine) manufactured by Shimadzu Corporation, a metal plate was pressed against the side of the resulting cylindrical cured product, and shear was applied to the cured product on the glass epoxy substrate at a shear rate of 5 mm / min, and the strength (adhesion strength) was measured when the cured product broke or peeled from the glass epoxy substrate. Adhesion strength was evaluated as "A" for 4 MPa or more, "B" for 2 MPa or more but less than 4 MPa, and "C" for less than 2 MPa.

[0065] (Glass Transition Temperature) The photocurable resin composition was cured using an LED-UV irradiator to prepare a predetermined test piece (length 20 mm x width 5 mm x thickness 1 mm). Using the obtained test piece, the glass transition temperature Tg was measured using a UBM Rheogel E-4000 with a chuck distance of 20 mm, a fundamental frequency of 10 Hz, and strain in automatic control mode. The glass transition temperature was evaluated as "A" for temperatures of 150°C or higher, "B" for temperatures of 120°C or higher but less than 150°C, and "C" for temperatures less than 120°C.

[0066] (Linear expansion coefficient) The photocurable resin composition was cured using an LED-UV irradiator to prepare a predetermined test piece (length 20 mm × width 5 mm × thickness 1 mm). The linear expansion coefficient of the obtained test piece was measured using a thermomechanical analyzer TMA ("TMA8311" manufactured by Rigaku Corporation). The linear expansion coefficient from -40°C to the glass transition temperature was evaluated as "A" when it was less than 20 ppm, "B" when it was 20 ppm or more but less than 50 ppm, and "C" when it was 50 ppm or more.

[0067] (Dispersibility) The viscosity of the photocurable resin composition was measured at 25° C. using an E-type viscometer (Tokyo Keiki Co., Ltd.) A viscosity of less than 100 Pa·s was evaluated as “A”, and a viscosity of 100 Pa·s or more was evaluated as “B”.

[0068]

[0069]

[0070]

[0071] The results are shown in Tables 1 to 3. In Comparative Example 1, the component (A) was not blended, and therefore the adhesiveness was poor. In Comparative Example 2, the blended amount of component (B) was less than the specified amount, and therefore the cured product had a low glass transition temperature and a high linear expansion coefficient. In Comparative Example 3, the blended amount of component (B) was more than the specified amount, and therefore the glass transition temperature was high, but the adhesiveness was poor. In Comparative Example 4, the component (C) was not blended, and therefore the adhesiveness was poor.

[0072] In contrast, Examples 1 to 11 had excellent adhesiveness, and the cured products had high glass transition temperatures and excellent heat resistance. Furthermore, Examples 1 to 10, which contained silica, had excellent silica dispersibility and a low linear expansion coefficient.

[0073] The various numerical ranges described in this specification can be arbitrarily combined with their respective upper and lower limit values, and all such combinations are considered to be preferred numerical ranges described in this specification. Furthermore, a numerical range described as "X to Y" means from X to Y.

[0074] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their omissions, substitutions, modifications, etc. are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

Claims

1. A photocurable resin composition comprising: (A) component: an α-(unsaturated alkoxyalkyl) acrylic acid ester; (B) component: an alicyclic (meth)acrylate; and (C) component: a (meth)acrylamide derivative of a secondary amide and / or a (meth)acrylamide derivative of a tertiary amide, wherein the content of the (B) component is 30 to 60 parts by mass per 100 parts by mass of the total of the (A), (B), and (C) components.

2. The photocurable resin composition according to claim 1, further comprising silica.

3. The α-(unsaturated alkoxyalkyl)acrylic acid ester contains a compound represented by the following general formula (1): In the formula, R １ represents a monovalent organic group having 1 to 30 carbon atoms, and R ２ represents a methylene group which may have an alkyl group having 1 to 4 carbon atoms as a substituent, and R ３ and R ４ one of which represents a methylene group which may have an alkyl group having 1 to 4 carbon atoms as a substituent, and the other represents an oxygen atom; R ５ The photocurable resin composition according to claim 1, wherein represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an ester group.

4. The photocurable resin composition according to claim 1, wherein the molecular weight of the alicyclic (meth)acrylate is 500 or less.

5. The photocurable resin composition according to claim 1, wherein the alicyclic (meth)acrylate comprises an alicyclic di(meth)acrylate.

6. The photocurable resin composition according to claim 1, wherein the component (C) comprises a (meth)acrylamide derivative of the tertiary amide.

7. The photocurable resin composition according to claim 1, wherein the content of the component (A) is 5 to 50 parts by mass per 100 parts by mass of the total of the components (A), (B), and (C).

8. The photocurable resin composition according to any one of claims 1 to 7, which is used by applying it to a printed circuit board.

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

Images