WO2023085155A1

WO2023085155A1 - Curable resin composition, laminated structure, cured product, and electronic component

Info

Publication number: WO2023085155A1
Application number: PCT/JP2022/040692
Authority: WO
Inventors: ハヌルチャ; 英司播磨
Original assignee: 太陽インキ製造株式会社
Priority date: 2021-11-15
Filing date: 2022-10-31
Publication date: 2023-05-19
Also published as: CN118235089A

Abstract

[Problem] To provide: a curable resin composition that has excellent uniform dispersibility and dryness to the touch in a resin layer, and that yields a final cured product having excellent environmental reliability; and a laminate structure, a cured product, and an electronic component having a resin layer formed using the curable resin composition. [Solution] A curable resin composition containing (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) a photocurable compound containing no carboxyl groups, (D) an inorganic filler, and (E) a polymerization inhibitor, wherein the (C) photocurable compound containing no carboxyl groups includes (C-1) a photocurable compound having a weight average molecular weight of 2,000-10,000 and (C-2) a photocurable compound having a weight average molecular weight of 500 or more and less than 2,000, and the (C-1) photopolymerizable compound is included at a ratio of 25-500 parts by mass with respect to 1 part by mass of the (E) polymerization inhibitor.

Description

Curable resin composition, laminated structure, cured product and electronic component

The present invention relates to a curable resin composition, a laminated structure using the curable resin composition, and an electronic component using the curable resin composition or the laminated structure.

Printed wiring boards, in particular, solder resists used in package substrates (PKG) for mounting semiconductors such as CPUs of personal computers, APs of smartphones, and memories are generally liquid curable resin compositions or dry films. It is formed by curing the laminated structure. In addition, the solder resist is required to have fine opening properties (resolution) that enable formation of fine openings and patterns, crack resistance, and the like.

In order to satisfy these requirements, for example, Patent Document 1 discloses a photosensitive resin composition containing an acid-modified vinyl group-containing epoxy resin, a photopolymerization initiator, a polymerization inhibitor, and a photopolymerizable compound. .

According to the photosensitive resin composition of Patent Document 1, it is disclosed that not only is the resolution excellent, but also that the permanent mask resist as a cured product thereof is excellent in crack resistance, insulation reliability, and the like.

JP 2021-71563 A

However, in the curable resin composition used in the production of conventional solder resists for PKG, insufficient dispersion of the inorganic filler and polymerization inhibitor to be mixed, and the mixing of the carboxyl group-containing resin and the photocurable compound to be mixed. Due to insufficient compatibility and compatibility between photocurable compounds, resin grains may occur, and the environmental reliability of the final cured product is impaired. It's becoming clear.

In order to improve these insufficient dispersion and poor compatibility in the curable resin composition, it is conceivable to increase the amount of diluents such as organic solvents and low-viscosity photocurable compounds. However, when the blending ratio of the diluent increases, dryness to the touch may decrease when the curable resin composition is dried to form a resin layer, which may make it difficult to handle the laminated structure. . That is, when the resin layer of the laminated structure is adhered to the circuit board, the resin layer is usually laminated on the surface of the circuit board and then heated and pressed to adhere them together. When the layer is laminated on the surface of the circuit board, the layer sticks to the surface of the circuit board, and wrinkles may occur in the resin layer. As a result, the flatness of the surface of the resin layer bonded to the circuit board may deteriorate.

The present invention has been made in view of the above problems, and a final cured product having excellent uniform dispersibility of the curable resin composition, excellent dryness to the touch in the resin layer, and excellent environmental reliability can be obtained. An object of the present invention is to provide a curable resin composition. Another object of the present invention is to provide a laminate structure comprising a resin layer made of a curable resin composition, a cured product of the curable resin composition and the resin layer, and an electronic component comprising the cured product. That is.

The inventors have conducted extensive studies to achieve the above objectives. As a result, a combination of a high-molecular-weight photocurable compound and a low-molecular-weight photocurable compound is used as the photo-curable compound, and the compounding ratio of the high-molecular-weight photocurable compound and the polymerization inhibitor is within a predetermined range. By adjusting, the dispersibility of the inorganic filler and the polymerization inhibitor in the curable resin composition is improved, and the compatibility between the carboxyl group-containing resin and the photocurable compound and the compatibility between the photocurable compounds are improved. is also improved, and as a result, the dryness to the touch of the resin layer formed from the curable resin composition is improved, and the environmental reliability of the final cured product formed from the resin layer is also improved. was completed. That is, the gist of the present invention is as follows.

[1] (A) a carboxyl group-containing resin,
(B) a photoinitiator,
(C) a photocurable compound containing no carboxyl group;
(D) an inorganic filler, and (E) a polymerization inhibitor,
A curable resin composition comprising
(C) the photocurable compound containing no carboxyl group,
(C-1) a photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less;
(C-2) a photocurable compound having a weight average molecular weight of 500 or more and less than 2,000;
including
A curable resin composition in which the photocurable compound (C-1) is contained in an amount of 25 parts by mass or more and 500 parts by mass or less relative to 1 part by mass of the polymerization inhibitor (E).
[2] The curable resin composition according to [1], wherein the (C) photocurable compound containing no carboxyl group further includes (C-3) a photocurable compound having a weight average molecular weight of 100 or more and less than 500. thing.
[3] The photocurable compound (C-1) is contained in a proportion of 100 parts by mass or more and 400 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E) [1] or [2] The curable resin composition according to .
[4] The photocurable compound (C-1) is contained in a proportion of 100 parts by mass or more and 250 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E) [1] to [3] Curable resin composition according to any one of.
[5] The photocurable compound (C-2) is contained in a proportion of 50 parts by mass or more and 500 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E) [1] to [4] Curable resin composition according to any one of.
[6] The total amount of the photocurable compound (C-1) and the photocurable compound (C-2) is 75 parts by mass or more and 1000 parts by mass with respect to 1 part by mass of the polymerization inhibitor (E). The curable resin composition according to any one of [1] to [5], which is contained in a proportion of parts or less.
[7] A laminated structure comprising a film and a resin layer provided on the film,
A laminate structure, wherein the resin layer is made of the curable resin composition according to any one of [1] to [6].
[8] A cured product obtained by curing the curable resin composition according to any one of [1] to [6] or the resin layer of the laminated structure according to [7].
[9] An electronic component comprising the cured product according to [8].
Effect of the invention

According to the curable resin composition of the present invention, the dispersibility of the inorganic filler and the polymerization inhibitor is improved, and the compatibility between the carboxyl group-containing resin and the photocurable compound and the compatibility between the photocurable compounds are also improved. be done. As a result, the resin layer formed from the curable resin composition of the present invention has excellent dryness to the touch, and the final cured product formed from the resin layer has excellent environmental reliability.

FIG. 4 is a schematic diagram showing a method for measuring peel strength between a cured film and a CZ-treated surface of a CZ-treated copper foil substrate.

<Curable resin composition>
The curable resin composition according to the present invention includes (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) a photocurable compound containing no carboxyl group, (D) an inorganic filler, and (E) polymerization As the (C) photocurable compound containing no carboxyl group and containing an inhibitor as an essential component, the weight average molecular weight of the two photocurable compounds having a specific weight average molecular weight is 2,000 or more. 10,000 or less of the photocurable compound is contained in a specific ratio with respect to (E) the polymerization inhibitor. According to the present invention, the dispersibility of (D) an inorganic filler and (E) a polymerization inhibitor in a curable resin composition is improved, and (A) a carboxyl group-containing resin and (C) photocurable The compatibility with the compound and the compatibility between (C) the photocurable compounds are also improved, and as a result, the resin layer formed from the curable resin composition has excellent dryness to the touch, and the resin layer The final cured product formed from has excellent environmental reliability.

Although the detailed mechanism by which the curable resin composition according to the present invention has the above effects is not clear, it can be inferred as follows. That is, (C-1) the blending ratio of the photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less is less than 25 parts by weight with respect to 1 part by weight of the polymerization inhibitor (E). (D) inorganic filler and (E) polymerization inhibitor are difficult to uniformly disperse, and the cured product cannot be uniformly cured, resulting in a decrease in environmental reliability. On the other hand, when the mixing ratio of the photocurable compound (C-1) exceeds 500 parts by mass with respect to 1 part by mass of the polymerization inhibitor (E), (A) the carboxyl group-containing resin and (C) the photocurable Poor compatibility with compounds and poor compatibility between (C) photocurable compounds occur, and the dispersibility of the resin component also decreases. As a result, resin granules and the like may occur, and the environmental reliability of the cured product is lowered.

In the present invention, a curable resin is obtained by blending a photocurable compound having a relatively large molecular weight (component (C-1)) having a weight average molecular weight of 2,000 or more and 10,000 or less at a specific ratio. It is considered that the composition has an appropriate fluidity and the dispersibility of (D) the inorganic filler and (E) the polymerization inhibitor is improved, so that the environmental reliability of the cured product is improved. Further, by containing the photocurable compound (C-1) in a specific ratio, the compatibility between (A) the carboxyl group-containing resin and (C) the photocurable compound and (C) the photocurable compounds The compatibility of the resin is also improved, and the resin component can be uniformly dispersed without increasing the content of the solvent. It can be inferred that

[(A) Carboxyl Group-Containing Resin]
The (A) carboxyl group-containing resin contained in the curable resin composition of the present invention imparts alkali developability to the curable resin composition of the present invention by containing carboxyl groups.

(A) As the carboxyl group-containing resin, conventionally known various resins having a carboxyl group in the molecule can be used. In particular, a carboxyl group-containing resin having an ethylenically unsaturated double bond in the molecule is preferable from the viewpoint of photocurability and development resistance. The ethylenically unsaturated double bonds are preferably derived from acrylic acid or methacrylic acid or derivatives thereof. When only a carboxyl group-containing resin having no ethylenically unsaturated double bond is used, a compound having an ethylenically unsaturated group in the molecule described later, i.e., a photocurable compound is used in combination to sensitize the composition. give sex.

The weight average molecular weight of (A) the carboxyl group-containing resin is not particularly limited, but preferably (A) the carboxyl group-containing resin includes (A-1) a carboxyl group-containing resin having a weight average molecular weight of 5,000 or more. .

(A-1) The weight average molecular weight range of the carboxyl group-containing resin having a weight average molecular weight of 5,000 or more is, for example, 5,000 or more and 150,000 or less, preferably 6,000 or more and 100,000. Below, more preferably 7,000 or more and 50,000 or less.

Further, (A) a carboxyl group-containing resin includes (A-1) a carboxyl group-containing resin having a weight average molecular weight of 5,000 or more, and (A-2) a carboxyl group-containing resin having a weight average molecular weight of less than 5,000. It preferably contains a resin.

(A-2) The range of the weight average molecular weight of the carboxyl group-containing resin having a weight average molecular weight of less than 5,000 is, for example, 1,500 or more and less than 5,000, preferably 1,600 or more and 4,500 or less. and more preferably 1,800 or more and 4,000 or less.

In addition, (A) the carboxyl group-containing resin is (A-1) a carboxyl group-containing resin having a weight average molecular weight of 5,000 or more and (A-2) a carboxyl group-containing resin having a weight average molecular weight of less than 5,000. When included, the mixing ratio of the two is preferably in the range of (A-1):(A-2)=6:4 to 9:1 on the basis of parts by mass.

Here, the carboxyl group-containing resins (A-1) and (A-2) are preferably carboxyl group-containing resins each having an aromatic ring, more preferably each having a novolac structure. is. When the carboxyl group-containing resins (A-1) and (A-2) are carboxyl group-containing resins each having an aromatic ring, the uniform dispersibility of the curable resin composition is further improved.

In the present invention, the value of the weight average molecular weight (Mw) is a value measured by the gel permeation chromatography (GPC) method (polystyrene standard) using the following measurement apparatus and measurement conditions.

Measuring device: "Waters 2695" manufactured by Waters
Detector: Waters 2414 RI (differential refractometer)
Column: Waters "HSPgel Column, HR MB-L, 3 μm, 6 mm × 150 mm" × 2 + Waters "HSPgel Column, HR1, 3 μm, 6 mm × 150 mm" × 2

Measurement conditions: Column temperature: 40°C
RI detector set temperature: 35°C
Developing solvent: Tetrahydrofuran Flow rate: 0.5 ml/min Sample volume: 10 μl
Sample concentration: 0.5 wt%

(A) Specific examples of the carboxyl group-containing resin include the following compounds. The following compounds may be oligomers or polymers.

(1) A carboxyl group-containing photosensitive resin obtained by reacting (meth)acrylic acid with a bifunctional or more polyfunctional epoxy resin and adding a dibasic acid anhydride to the hydroxyl groups present in the side chains.

(2) A carboxyl group-containing photosensitizer obtained by reacting (meth)acrylic acid with a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl groups of a bifunctional epoxy resin with epichlorohydrin, and adding a dibasic acid anhydride to the resulting hydroxyl groups. synthetic resin.

(3) an epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol; Maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and adipine are reacted with an unsaturated group-containing monocarboxylic acid such as acrylic acid, and the alcoholic hydroxyl group of the resulting reaction product is treated with A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride such as an acid.

(4) A reaction obtained by reacting a reaction product obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide and reacting an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting the product with a polybasic acid anhydride.

(5) A reaction obtained by reacting a reaction product obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate with a monocarboxylic acid containing an unsaturated group. A carboxyl group-containing photosensitive resin obtained by reacting the product with a polybasic acid anhydride.

(6) A carboxyl group-containing photosensitive resin obtained by adding a compound having one epoxy group and one or more (meth)acryloyl groups in one molecule to the resins of (1) to (5).

In this specification, (meth)acrylate is a generic term for acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

(A) The acid value of the carboxyl group-containing resin is preferably 40 to 200 mgKOH/g, more preferably 50 to 160 mgKOH/g, from the viewpoint of improving the developability of the curable resin composition.

(A) Carboxyl group-containing resins are not limited to those listed above, and one type may be used alone, or a plurality of types may be mixed and used. Among them, the carboxyl group-containing resin (4) or the carboxyl group-containing resin (5) can be preferably used because the cured product is excellent in environmental reliability.

(A) The amount of the carboxyl group-containing resin is preferably 10 parts by mass or more and 60 parts by mass or less, more preferably 15 parts by mass or more, relative to 100 parts by mass of the solid content of the curable resin composition of the present invention. It is 45 parts by mass or less.

[(B) Photoinitiator]
(B) The photopolymerization initiator may be appropriately selected according to the application and desired properties of the curable resin composition of the present invention.

As the photopolymerization initiator (B), known photopolymerization initiators can be used without particular limitation. benzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, Bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2 bisacylphosphine oxides such as ,5-dimethylphenylphosphine oxide and bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6- Dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenyl monoacylphosphine oxides such as phosphine oxide; acylphosphinates such as ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate; 1-hydroxy-cyclohexylphenyl ketone, 1-[4-(2 -hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl] Hydroxyacetophenones such as phenyl}-2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n- benzoins such as propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, etc. benzophenones; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4 -(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-[(4 -methylphenyl)methyl)]-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone and other acetophenones; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2 ,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone , 1-chloroanthraquinone, 2-amyl anthraquinone, anthraquinones such as 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, p -benzoic acid esters such as dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6 -(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) and other oxime esters; bis(η5-2,4-cyclopentadien-1-yl)-bis( 2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyrr-1-yl) ) titanocene such as ethyl)phenyl]titanium; phenyldisulfide 2-nitrofluorene, butyroin, anisoine ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like. (B) A photoinitiator may be used individually by 1 type, and may be used in combination of 2 or more type. Among the above, it is preferable to include at least one of bisacylphosphine oxides, monoacylphosphine oxides, acylphosphinates, and the like.

(B) The amount of the photopolymerization initiator is 0.1 parts by mass or more and 40 parts by mass or less with respect to a total of 100 parts by mass of (A) the carboxyl group-containing resin and (C) the photocurable compound that does not contain a carboxyl group. and more preferably 0.3 parts by mass or more and 15 parts by mass or less. When the amount is 0.1 part by mass or more, good resolution is obtained by exposure, and when the amount is 40 parts by mass or less, the properties of the cured product are good.

[(C) Photocurable compound containing no carboxyl group]
(C) The photocurable compound containing no carboxyl group is a compound that imparts photocurability to the curable resin composition of the present invention by having an ethylenically unsaturated double bond in the molecule.

(C) As a photocurable compound containing no carboxyl group, (C-1) a photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less, and (C-2) a weight average molecular weight of 500 or more and 2 ,000 of photocurable compounds. In the present invention, the photocurable compound (C-1) is contained in a proportion of 25 parts by mass or more and 500 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E) described later. Thus, by containing a photocurable compound having a specific molecular weight in a specific ratio, the dispersibility of (D) the inorganic filler and (E) the polymerization inhibitor in the curable resin composition is improved. In addition, the compatibility between (A) the carboxyl group-containing resin and (C) the photocurable compound and the compatibility between (C) the photocurable compounds are also improved, and as a result, the curable resin composition is formed. The resulting resin layer has excellent dryness to the touch, and the final cured product formed from the resin layer has excellent environmental reliability. The method for measuring the weight average molecular weight of (C) the photocurable compound containing no carboxyl group follows the above gel permeation chromatography (GPC) method (polystyrene standard).

(C-1) The photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less includes a bifunctional phosphorus-modified acrylate oligomer (RAYLOCK-1722, manufactured by Daicel, Mw: 3,000), a bifunctional Urethane-based (meth)acrylate oligomer polybutadiene acrylate resin (TE-2000, manufactured by Nippon Soda Co., Ltd. Mw: 2,500), bifunctional polycarbonate urethane-based acrylate oligomer (UN-9000PEP, manufactured by Negami Kogyo Co., Ltd. Mw: 5,000), etc. and (meth)acryloyl group-containing compounds of. In addition, bifunctional means having two (meth)acryloyl groups. The same applies hereinafter.

(C-1) The photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less preferably has an aromatic ring from the viewpoint of dispersibility, dryness to the touch, and environmental reliability. Those having a novolak structure are more preferred. In particular, from the viewpoint of excellent dispersibility, dryness to the touch, and environmental reliability, (C-1) a photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less, poly(bisphenol A or bisphenol F) Some or all of the phenolic hydroxyl groups of the phenolic compound (a) having four or more phenolic hydroxyl groups in the molecule containing the structure of the following general formula (1) obtained by the condensation reaction of a methylol compound and a phenol , reacting with a compound (b) having a cyclic ether group to convert it to an oxyalkyl group having an alcoholic hydroxyl group, and adding acrylic acid and/or methacrylic acid (c) to the terminal hydroxyl group of the resulting oxyalkyl group. It is preferable to use a photocurable compound having a (meth)acryloyl group added to the side chain.

(wherein R ₁ is -C(CH ₃ ) ₂ - or -CH ₂ -, each R ₂ independently represents a hydrocarbon group having 1 to 11 carbon atoms, each a independently represents 0 to represents an integer of 3, n independently represents an integer of 1 to 2, and m represents an integer of 1 to 10.)

The phenol compound (a) having two or more phenolic hydroxyl groups in the molecule containing the structure of the general formula (1) is a polymethylol compound (a1) of bisphenol A or bisphenol F and a phenol (a2) with an acidic catalyst. It is obtained by a condensation reaction in the presence of

As the phenols (a2), phenol, alkylphenols such as various cresols, various xylenols, and naphthols can be used, and o-cresol and 2,6-xylenol are preferably used. Moreover, you may mix and use these.

The addition ratio of the compound (b) having a cyclic ether group such as an alkylene oxide or a cyclic carbonate to the phenol compound (a) is 0.5 mol to 5.0 mol per equivalent of the phenolic hydroxyl group of the phenol compound (a). Yes, preferably 0.8 to 3.0 mol. By setting the addition ratio in the range of 0.5 to 5.0 mol, the photocurability of the curable resin composition is improved, and dryness to the touch is improved when a resin layer is formed.

(C-2) As the photocurable compound having a weight average molecular weight of 500 or more and less than 2,000, any photocurable compound having a weight average molecular weight of 500 or more and less than 2,000 may be used without any particular limitation. It may optionally have functional groups or structural moieties such as hydroxyl groups, ether bonds, ketones, aromatic rings, saturated or non-aromatic unsaturated carbocyclic rings, and heterocyclic rings.

(C-2) Examples of photocurable compounds having a weight average molecular weight of 500 or more and less than 2,000 include glycol di(meth)acrylates such as caprolactone-modified neopentyl hydroxypivalate glycol di(meth)acrylate; EO (ethylene oxide) adduct di (meth) acrylate of polyhydric phenol such as PO (propylene oxide) adduct di (meth) acrylate of bisphenol A RO (alkylene oxide) adduct di (meth) acrylate ( In addition to bisphenol A, examples of polyhydric phenols include bisphenols such as bisphenol AP, bisphenol B, bisphenol BP, bisphenol E, bisphenol F, bisphenol M, bisphenol P, bisphenol PH, and bisphenol Z, and biphenols.); 5- to 8-functional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate and dipentaerythritol monohydroxypenta(meth)acrylate; exemplified by silsesquioxane-modified 2- to 5-functional (meth)acrylates; polyfunctional (meth)acrylates; polyfunctional (meth)acrylates such as ε-caprolactone-modified tris(acroxyethyl)isocyanurate; or combinations of two or more thereof.

(C-2) The photocurable compound having a weight average molecular weight of 500 or more and less than 2,000 is dipentaerythritol hexa(meth)acrylate, dipentaerythritol mono It is preferably a 5- to 8-functional (meth)acryloyl group-containing compound having no cyclic structure, such as hydroxypenta(meth)acrylate.

(C-1) The photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less is contained in a ratio of 25 parts by weight or more and 500 parts by weight or less with respect to 1 part by weight of the polymerization inhibitor (E) described later. and preferably 100 parts by mass or more and 400 parts by mass or less. By setting the blending ratio to 100 parts by mass or more and 250 parts by mass or less, the dryness to the touch of the resin layer or the environmental reliability of the cured product is further improved. More preferably, it is 100 parts by mass or more and 250 parts by mass or less. By setting the mixing ratio to 100 parts by mass or more and 250 parts by mass or less, the environmental reliability of the cured product is further improved.

In addition, (C-2) a photocurable compound having a weight average molecular weight of 500 or more and less than 2,000 is used in a proportion of 50 parts by mass or more and 500 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E) described later. It is preferably contained, more preferably 100 parts by mass or more and 300 parts by mass or less. (C-2) By adjusting the blending ratio of the photocurable compound having a weight average molecular weight of 500 or more and less than 2,000 to 50 parts by mass or more and 500 parts by mass or less, the uniform dispersibility of the curable resin composition and the formation of the resin layer It is possible to improve both the dryness to the touch and the environmental reliability of the cured product of the curable resin composition.

Furthermore, the total blending ratio of (C-1) a photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less and (C-2) a photocurable compound having a weight average molecular weight of 500 or more and less than 2,000 is The total amount is preferably 75 parts by mass or more and 1000 parts by mass or less, more preferably 200 parts by mass or more and 700 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E) described later. By setting the total mixing ratio of the photocurable compound (C-1) and the photocurable compound (C-2) in the above range, the uniform dispersibility of the curable resin composition and the dryness to the touch of the resin layer All of the environmental reliability of the cured product of the curable resin composition and the environmental reliability can be improved.

In addition, the curable resin composition of the present invention may further contain (C-3) a photocurable compound having a weight average molecular weight of 100 or more and less than 500 as (C) a photocurable compound containing no carboxyl group. preferable. By the curable resin composition containing (C-3) a photocurable compound having a weight average molecular weight of 100 or more and less than 500, while maintaining the dryness to the touch of the resin layer, the inorganic The dispersibility of the filler and the polymerization inhibitor, the compatibility between the carboxyl group-containing resin and the photocurable compound, and the compatibility between the photocurable compounds are further improved, and the uniform dispersibility of the curable resin composition is improved. .

(C-3) As the photocurable compound having a weight average molecular weight of 100 or more and less than 500, any photocurable compound having a weight average molecular weight of 100 or more and less than 500 and containing no carboxyl group can be used without particular limitation. It may optionally have a functional group or structure such as a hydroxyl group, an ether bond, a ketone, an aromatic ring, a saturated or non-aromatic unsaturated carbocyclic ring, or a heterocyclic ring.

(C-3) Photocurable compounds having a weight average molecular weight of 100 or more and less than 500 include, for example, 2-hydroxy-3-phenoxyethyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, 2 - mono (meth) acrylates having a hydroxyl group such as hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate; α-(allyloxy) methyl) methyl acrylate; 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di( Diol di(meth)acrylate such as meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di( meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol containing at least ethylene oxide and propylene oxide di(meth)acrylates of diols obtained by adding any one; Di(meth)acrylates having a cyclic structure; pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, propylene oxide-modified Trimethylolpropane tri(meth)acrylate, epichlorohydrin-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, ethylene oxide-modified phosphoric acid tri(meth)acrylate, epichlorohydrin-modified glycerol tri(meth)acrylate trifunctional or higher polyfunctional (meth)acrylate such as (meth)acrylate; or a combination of two or more thereof.

(C-3) The photocurable compound having a weight-average molecular weight of 100 or more and less than 500 is preferably saturated or non-aromatic from the viewpoint of dispersibility, dryness to the touch and environmental reliability. Bifunctional (meth)acryloyl group-containing compounds containing one or more rings are preferred.

(C-3) When a photocurable compound having a weight average molecular weight of 100 or more and less than 500 is contained in the curable resin composition of the present invention, the mixing ratio thereof is, for example, (C-1) weight average molecular weight of 2, 0.5 parts by mass or more and 25 parts by mass with respect to 100 parts by mass of the total amount of the photocurable compound having a weight average molecular weight of 000 or more and 10,000 or less and (C-2) a photocurable compound having a weight average molecular weight of 500 or more and less than 2,000 It is preferably 1 part by mass or less, more preferably 1 part by mass or more and 15 parts by mass or less. Further, the curable resin composition of the present invention contains (C-1) a photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less and (C-2) a weight average molecular weight of 500 or more and less than 2,000. and (C-3) a photocurable compound having a weight average molecular weight of 100 or more and less than 500, and (C-1) a light having a weight average molecular weight of 2,000 or more and 10,000 or less By containing the curable compound in a proportion of 50 parts by mass or more and 300 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E), (C-3) a photocurable compound having a weight average molecular weight of 100 or more and less than 500 contributes to fluidity during dispersion. As a result, the uniform dispersibility of the curable resin composition, the dryness to the touch of the resin layer formed from the curable resin composition, and the environmental reliability of the cured product of the curable resin composition were all particularly excellent. Become.

[(D) inorganic filler]
The curable resin composition of the present invention contains (D) an inorganic filler. Inorganic fillers can be added to suppress curing shrinkage of the curable resin composition and improve properties such as adhesion and hardness of the cured product. The inorganic filler is uniformly dispersed in the curable resin composition of the invention. Therefore, the effect of improving the environmental reliability of the cured product can be obtained satisfactorily. (D) Inorganic fillers are not particularly limited, and known and commonly used inorganic fillers such as silica, Neuburg silica, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica. , aluminum hydroxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, mineral wool, aluminum silicate, calcium silicate, zinc white, and other inorganic fillers can be used, even in combinations thereof. good.

(D) As the inorganic filler, a combination of barium sulfate and silica is preferable from the viewpoint of suppressing curing shrinkage of the curable resin composition and improving properties such as adhesion and hardness of the cured product. When barium sulfate and silica are contained in combination, the mixing ratio of the two is, for example, 100:20 to 100:60, preferably 100:30 to 100:50, based on mass. By setting the mixing ratio within the above range, the environmental reliability and adhesion of the cured product can be improved.

The inorganic filler may be subjected to a photoreactive surface treatment so as to have a vinyl group, a styryl group, a methacrylic group, an acrylic group, etc. as a photocurable reactive group. In addition, a thermoreactive surface treatment may be performed so as to have a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, an imino group, an epoxy group, an oxetanyl group, a mercapto group, an oxazoline group, etc. as a thermosetting reactive group. .

(D) The introduction method for introducing a curable reactive group onto the surface of the inorganic filler is not particularly limited, and may be introduced using a known and commonly used method. A surface treatment agent having a curable reactive group, such as The surface of the inorganic filler may be treated with a coupling agent or the like having a curable reactive group.

In the curable resin composition of the present invention, (D) the inorganic filler preferably has an average particle size of 1 μm or less, more preferably 0.8 μm or less. In the present specification, the average particle size refers to the cumulative average particle size 50% (D50) value when the particle size distribution is created on a volume basis, and It can be determined by a measuring device based on the optical scattering method. Examples of the measuring device by the laser diffraction method include Microtrac MT3300EXII manufactured by Microtrac Bell, and Nanotrac Wave II UT151 manufactured by Microtrac Bell as the measuring device by the dynamic light scattering method. As the measurement sample, (D) an inorganic filler dispersed in PMA (propylene glycol monomethyl ether acetate) can be preferably used.

(D) The amount of the inorganic filler compounded is, for example, 20 parts by mass or more and 60 parts by mass or less, preferably 25 parts by mass or more and 50 parts by mass with respect to 100 parts by mass of the solid content of the curable resin composition of the present invention. It is below.

[(E) polymerization inhibitor]
The curable resin composition of the present invention contains (E) a polymerization inhibitor. (E) The polymerization inhibitor is uniformly dispersed in the curable resin composition of the present invention. Therefore, the resin layer formed from the curable resin composition has excellent dryness to the touch, and the cured product has excellent environmental reliability.

(E) The polymerization inhibitor is not particularly limited, and known and commonly used polymerization inhibitors can be used. (E) The polymerization inhibitor is preferably, for example, at least one of naphthalene derivatives, naphthoquinone and naphthoquinone derivatives.

When the curable resin composition of the present invention contains at least one of nanaphthalene derivatives, naphthoquinone and naphthoquinone derivatives as (E) a polymerization inhibitor, stable resolution can be obtained.

As the naphthalene derivative used in the present invention, ammonium 1,4-dihydroxy-2-naphthalenesulfonate, 4-methoxy-1-naphthol and the like can be used. As naphthoquinone and its derivatives, 1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone, anthrone and the like can be used.

Commercially available naphthalene derivatives include, for example, Quinopower (registered trademark) QS-30, WSI, Quinopower MNT (all manufactured by Air Water Performance Chemicals, etc.).

Commercial products of naphthoquinone and naphthoquinone derivatives include, for example, Quinopower (registered trademark) NQI, Quinopower LSN, Quinopower ATR (all manufactured by Kawasaki Kasei), 1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone, and anthrone. (all manufactured by Tokyo Kasei Kogyo Co., Ltd.).

[Coloring agent]
A coloring agent can be added to the curable resin composition of the present invention. As the colorant, known and commonly used colorants such as red, blue, green and yellow can be used, and any of pigments, dyes and pigments can be used. The curable resin composition of the present invention exhibits excellent dispersibility even when a coloring agent is added. In the curable resin composition for solder resist applications, for example, phthalocyanine blue, anthraquinone yellow colorant, carbon black and the like are blended.

In order to achieve both excellent dispersibility and concealability of the underlying circuit board, the amount of the colorant compounded is 0.01 part by mass or more and 5 parts by mass with respect to 100 parts by mass of the solid content of the curable resin composition. The following are preferable.

[Thermosetting component]
The curable resin composition of the present invention preferably contains a thermosetting component. By including a thermosetting component, the functionality of the cured product of the curable resin composition of the present invention, such as heat resistance and plating resistance, can be improved.

Thermosetting components include known and commonly used thermosetting compounds such as isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy resins, polyfunctional oxetane compounds, episulfide resins, melamine resins, and silicone resins. ingredients can be used, and these can be used alone or in combination of two or more. Epoxy resin is preferred.

As the epoxy resin, a known and commonly used polyfunctional epoxy resin having at least two epoxy groups in one molecule can be suitably used.

Examples of epoxy resins include jER828, jER834, jER1001, and jER1004 manufactured by Mitsubishi Chemical Corporation; EPICLON 840, 850, 850-S, 1050, and 2055 manufactured by DIC Corporation; YD-013, YD-127, YD-128, D.D. E. R. 317, D. E. R. 331, D. E. R. 661, D. E. R. 664, Sumie-Epoxy ESA-011, ESA-014, ELA-115, ELA-128, etc. manufactured by Sumitomo Chemical Co., Ltd. (all trade names); bisphenol A type epoxy resins; EPICLON 152, 165, Epototo YDB-400 and YDB-500 manufactured by Nippon Steel Chemical & Materials, D.O. manufactured by Dow Chemical. E. R. 542, Sumie-epoxy ESB-400, ESB-700, etc. (both trade names) manufactured by Sumitomo Chemical Co., Ltd.; jER152 and jER154 manufactured by Mitsubishi Chemical Co., Ltd.; E. N. 431, D. E. N. 438, DIC's EPICLON N-730, N-770, N-865, Nippon Kayaku's EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, NC-3000, NC -3000H, sumi-epoxy ESCN-195X, ESCN-220 manufactured by Sumitomo Chemical Co., Ltd., YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7 manufactured by Nippon Steel Chemical & Materials Co., Ltd. , YDCN-700-10, YDCN-701, YDCN-704, YDCN-704A, DIC's EPICLON N-680, N-690, N-695, N-870 (all trade names), etc. Resin: EPICLON 830 manufactured by DIC Corporation, jER807 manufactured by Mitsubishi Chemical Corporation, Epotato YDF-170, YDF-175, YDF-2004 manufactured by Nippon Steel Chemical & Materials Co., Ltd. (all trade names) bisphenol F type epoxy resins; Japan Hydrogenated bisphenol A epoxy resin such as Epotato ST-2004, ST-2007, ST-3000 (trade name) manufactured by Iron Chemical & Materials, YX8034 manufactured by Mitsubishi Chemical; jER604 manufactured by Mitsubishi Chemical, Nippon Steel Chemical Glycidylamine type epoxy resins such as Epotato YH-434 manufactured by &Materials Co., Ltd., Sumi-Epoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd. (both trade names); Hydantoin type epoxy resins; Celoxide 2021 manufactured by Daicel Corporation (both (trade name) alicyclic epoxy resin; YL-933 manufactured by Mitsubishi Chemical Co., Ltd.; Bixylenol type or biphenol type epoxy resins such as YL-6056, YX-4000, YL-6121 (all trade names) manufactured by the company, or mixtures thereof; EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by ADEKA , DIC's EXA-1514 (trade name) and other bisphenol S type epoxy resins; Mitsubishi Chemical Co.'s jER157S (trade name) and other bisphenol A novolac type epoxy resins; tetraphenylol ethane type epoxy resins manufactured by Nissan Chemical Co., Ltd.; heterocyclic epoxy resins such as TEPIC manufactured by Nissan Chemical Co., Ltd.; diglycidyl phthalate resins such as BLEMMER DGT manufactured by NOF; Tetraglycidyl xylenoyl ethane resin such as ZX-1063 manufactured by Material Co., Ltd.; Naphthalene group-containing resin such as ESN-190, ESN-360 manufactured by Nippon Steel Chemical & Material, HP-4032, EXA-4750, EXA-4700 manufactured by DIC, etc. Epoxy resin; epoxy resin having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by DIC; glycidyl methacrylate copolymer epoxy resin such as CP-50S and CP-50M manufactured by NOF; Copolymerized epoxy resins of glycidyl methacrylate; CTBN-modified epoxy resins (eg, YR-102, YR-450, etc. manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc., but not limited to these.

When the curable resin composition of the present invention contains a thermosetting component, the amount of the thermosetting component is, for example, 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing resin (A). is.

[Other ingredients]
The curable resin composition of the present invention further optionally contains an organic solvent, an ultraviolet absorber, a silane coupling agent, a plasticizer, a flame retardant, an antistatic agent, an antioxidant, an antibacterial/antifungal agent, and an antifoaming agent. agent, leveling agent, thickener, adhesion imparting agent, thixotropic agent, photoinitiator aid, sensitizer, thermoplastic resin, organic filler, release agent, surface treatment agent, dispersant, dispersing aid, Components such as surface modifiers, stabilizers, and phosphors can be incorporated. As these, those known and commonly used in the field of electronic materials can be used.

<Laminated structure>
The laminated structure of the present invention has a film and a resin layer formed of the curable resin composition of the present invention in this order. In addition, the resin layer may be a single layer, or may have a laminated structure of two or more resin layers.

The laminated structure can be manufactured, for example, as follows. That is, first, on the first film (support film), the curable resin composition of the present invention constituting the resin layer is adjusted to an appropriate viscosity as it is, or diluted with an organic solvent as necessary, and It is applied by a known method such as a comma coater according to a conventional method, and dried at a temperature of 50 to 130° C. for 1 to 30 minutes. When the resin layer has a laminated structure of two or more layers, the coating operation is repeated with or without changing the resin composition to be applied to form two or more resin layers on the first film. Laminated structures can be made.

A peelable second film (protective film) can be further laminated on this laminated structure for the purpose of preventing dust from adhering to the surface of the resin layer. As the first film and the second film, conventionally known plastic films can be used as appropriate. It is preferably smaller than the adhesive force. The thicknesses of the first film and the second film are not particularly limited, but are generally selected appropriately within the range of 10 to 150 μm.

<Cured product>
The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer of the laminated structure.

In order to form a cured product using the curable resin composition of the present invention or the resin layer of the laminated structure, the curable resin composition of the present invention is applied onto a substrate, and if necessary, the solvent is evaporated and dried. By exposing (light irradiation) to the resin layer obtained after the above, or to the resin layer formed by attaching the resin layer of the laminated structure to the substrate, an exposed portion (light irradiated portion ) hardens. Specifically, by a contact or non-contact method, selective exposure to active energy rays is performed through a patterned photomask, or direct pattern exposure is performed using a laser direct exposure machine, and the unexposed areas are developed with an alkaline aqueous solution. By doing so, a pattern of the resin layer is formed. The pattern of the obtained resin layer may be irradiated with ultraviolet rays and then heat-cured, or after heat-curing and then irradiated with ultraviolet rays, or only with heat-curing for final final curing (main curing). Various properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, electrical properties, etc. An excellent cured product can be formed.

Examples of the substrate include printed wiring boards and flexible printed wiring boards on which circuits are formed in advance with copper or the like, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth/non-woven cloth epoxy, glass cloth/paper epoxy, Copper-clad laminates of all grades (FR-4, etc.) using materials such as copper-clad laminates for high-frequency circuits using synthetic fiber epoxy, fluororesin, polyethylene, polyphenylene ether, polyphenylene oxide, cyanate, etc. , metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like.

Volatile drying or heat curing when forming the above-mentioned cured product can be performed, for example, by using a hot air circulation drying oven, an IR oven, a hot plate, a convection oven, etc. A method of bringing hot air into countercurrent contact and a method of blowing hot air onto the support from a nozzle) can be used.

In addition, as an exposure machine used for the above active energy ray irradiation, if it is equipped with a high pressure mercury lamp, ultra high pressure mercury lamp, metal halide lamp, mercury short arc lamp, etc., and irradiates ultraviolet rays in the range of 350 to 450 nm Well, in addition, a direct writing device (eg, a laser direct imaging device that writes an image with a laser directly from CAD data from a computer) can also be used. The lamp light source or laser light source of the direct writing apparatus may have a maximum wavelength in the range of 350 to 410 nm. The amount of exposure for image formation varies depending on the film thickness and the like, but can generally be in the range of 20-1000 mJ/cm ² , preferably in the range of 20-800 mJ/cm ² .

Examples of the developing method include a dipping method, a shower method, a spray method, a brush method, and the like. Alkaline aqueous solutions such as ammonia and amines can be used.

<Electronic parts>
Moreover, the present invention can also provide an electronic component having the cured product.

By using the curable resin composition of the present invention, electronic components with high quality, durability and reliability are provided.

In the present invention, electronic components refer to components used in electronic circuits, including active components such as printed wiring boards, transistors, light emitting diodes, and laser diodes, as well as passive components such as resistors, capacitors, inductors, and connectors.

It should be noted that the present invention is not limited to the configurations and examples of the above embodiments, and various modifications are possible within the scope of the gist of the invention.

The present invention will be specifically described below with reference to examples, but the present invention is not limited only to these examples. In addition, "part" shall mean the mass part of solid content unless there is particular notice below.

(A) Preparation of carboxyl group-containing resin [Synthesis Example 1]
<Synthesis of carboxyl group-containing resin A-1>
A flask equipped with a condenser and a stirrer was charged with 583.7 parts by mass of bisphenol A, 291.8 parts by mass of water, and 830.7 parts by mass of 37% by mass formalin. 291.8 parts by mass was added and reacted at 50° C. for 10 hours.

After the reaction was completed, the mixture was cooled to 40°C and neutralized to pH 4 with a 37.5% phosphoric acid aqueous solution while maintaining the temperature below 40°C. After that, the mixture was allowed to stand and the water layer was separated. After separation, methyl isobutyl ketone was added and dissolved uniformly, washed with distilled water three times, and water, solvent and the like were removed under reduced pressure at a temperature of 50°C or less.

The obtained polymethylol compound was dissolved in 704 parts by mass of methanol to obtain 1574.4 parts by mass of a methanol solution of the polymethylol compound. A portion of the obtained methanol solution of the polymethylol compound was dried in a vacuum dryer at room temperature to find that the solid content was 55.2%.

A flask equipped with a condenser and a stirrer was charged with 640 parts by mass of the methanol solution of the polymethylol compound obtained above and 563.2 parts by mass of 2,6-xylenol and uniformly dissolved at 50°C. After uniformly dissolving, methanol was removed under reduced pressure at a temperature of 50°C or less.

After that, 10.2 parts by mass of oxalic acid was added and reacted at 100°C for 10 hours. After completion of the reaction, the distillate was removed at 180° C. under reduced pressure of 50 mmHg to obtain 704 parts by mass of Novolak Resin A.

166.4 parts by mass of novolac resin A, 3.3 parts by mass of 50% sodium hydroxide aqueous solution, toluene/methyl isobutyl ketone (mass ratio = 2 /1) 120 parts by mass of ethylene oxide was charged, the inside of the system was replaced with nitrogen while stirring, the temperature was raised, and 57.6 parts by mass of ethylene oxide was gradually introduced under the conditions of 150°C and 8 kg/cm ² . reacted. The reaction was continued for about 4 hours until the gauge pressure reached 0.0 kg/cm ² and then cooled to room temperature.

4.2 parts by mass of a 36% hydrochloric acid aqueous solution was added to and mixed with this reaction solution to neutralize the sodium hydroxide. This neutralization reaction product was diluted with toluene, washed with distilled water three times, and the solvent was removed by an evaporator to give a hydroxyl value of 175 g/eq. An ethylene oxide adduct of novolac resin A was obtained. In this case, 1 mol of ethylene oxide was added on average per equivalent of phenolic hydroxyl group.

224 parts by mass of the ethylene oxide adduct of the obtained novolac resin A, 64 parts by mass of acrylic acid, 3.8 parts by mass of p-toluenesulfonic acid, 0.13 parts by mass of hydroquinone monomethyl ether, and 166.4 parts by mass of toluene were mixed with a stirrer. , a thermometer, and an air blowing tube, and stirred while blowing in air to raise the temperature to 115 ° C., and distill off the water produced by the reaction as an azeotrope with toluene for another 4 hours. After reacting, it was cooled to room temperature.

The resulting reaction solution was washed with a 5% NaCl aqueous solution, toluene was removed by distillation under reduced pressure, and diethylene glycol monoethyl ether acetate was added to obtain an acrylate resin solution with a non-volatile content of 68%.

Next, 399.4 parts by mass of the obtained acrylate resin solution, 0.13 parts by mass of hydroquinone monomethyl ether, and 0.38 parts by mass of triphenylphosphine were charged into a four-necked flask equipped with a stirrer and a reflux condenser, This mixture was heated to 110° C., 57.6 parts by mass of tetrahydrophthalic anhydride was added, reacted for 4 hours, cooled, and taken out. The carboxyl group-containing resin A-1 thus obtained had a nonvolatile content of 72% by mass and a solid content acid value of 65 mgKOH/g. The weight average molecular weight of the carboxyl group-containing resin A-1 was 13,000 when measured by gel permeation chromatography (GPC) using polystyrene as a standard substance as described above.

[Synthesis Example 2]
<Synthesis of carboxyl group-containing resin A-2>
An autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device was charged with 152.8 mass of novolak cresol resin (trade name "Shonol CRG951", manufactured by Aica Kogyo Co., Ltd., OH equivalent: 119.4). 1.52 parts by mass of potassium hydroxide and 152.8 parts by mass of toluene were charged, and the inside of the system was replaced with nitrogen while stirring, followed by heating.

Next, 81.7 parts by mass of propylene oxide was gradually added dropwise and reacted for 16 hours under conditions of 125 to 132° C. and 0 to 4.8 kg/cm ² to obtain a reaction solution. After cooling to room temperature, 2 parts by weight of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide, resulting in a non-volatile content of 62.1% by weight and a hydroxyl value of 182.2 g/eq. A propylene oxide reaction solution of a novolak-type cresol resin was obtained. This was obtained by adding an average of 1.08 mol of alkylene oxide per equivalent of phenolic hydroxyl group.

375.0 parts by mass of the alkylene oxide reaction solution of the obtained novolak-type cresol resin, 55.3 parts by mass of acrylic acid, 14.8 parts by mass of methanesulfonic acid, 0.23 parts by mass of methylhydroquinone, and 323 parts by mass of toluene. 7 parts by mass were charged into a reactor equipped with a stirrer, a thermometer and an air blowing pipe, and reacted at 110° C. for 12 hours while blowing air at a rate of 10 ml/min and stirring. 16.1 parts by mass of water was distilled as an azeotrope with toluene from the water produced by the reaction.

After cooling to room temperature, the resulting reaction solution was neutralized with 45.2 parts by mass of a 15% aqueous sodium hydroxide solution, and then washed with water.

After that, the toluene was distilled off while substituting 151.2 parts by mass of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak-type acrylate resin solution.

Next, 425.6 parts by mass of the obtained novolac-type acrylate resin solution and 1.56 parts by mass of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was supplied at 10 ml/min. 77.8 parts by mass of tetrahydrophthalic anhydride was gradually added while stirring at a rate of . The carboxyl group-containing resin A2 thus obtained had a nonvolatile content of 70.6% by mass and a solid acid value of 87.7 mgKOH/g. Further, the weight average molecular weight of the carboxyl group-containing resin A-2 was 2,400 when measured by gel permeation chromatography (GPC) using polystyrene as a standard substance as described above.

(C) Preparation of photocurable compound [Synthesis Example 3]
<(C-1) Synthesis of photocurable compound>
A flask equipped with a condenser and a stirrer was charged with 456 parts by mass of bisphenol A, 228 parts by mass of water, and 649 parts by mass of 37% by mass formalin, and the temperature was maintained at 40° C. or less. After completion of the addition, reaction was carried out at 50° C. for 10 hours. After completion of the reaction, the mixture was cooled to 40°C and neutralized to pH 4 with a 37.5% aqueous solution of phosphoric acid while maintaining the temperature below 40°C. After that, the mixture was allowed to stand and the water layer was separated. After separation, 300 parts by mass of methyl isobutyl ketone was added and dissolved uniformly, and then washed with 500 parts by mass of distilled water three times, and water, solvent and the like were removed under reduced pressure at a temperature of 50°C or less. The obtained polymethylol compound was dissolved in 550 parts by mass of methanol to obtain 1230 parts by mass of a methanol solution of the polymethylol compound. A portion of the obtained methanol solution of the polymethylol compound was dried in a vacuum dryer at room temperature to find that the solid content was 55.2% by mass.

500 parts by weight of the methanol solution of the obtained polymethylol compound and 440 parts by weight of 2,6-xylenol were charged and uniformly dissolved at 50°C. After uniformly dissolving, methanol was removed under reduced pressure at a temperature of 50°C or less. After that, 8 parts by mass of oxalic acid was added and reacted at 100° C. for 10 hours. After completion of the reaction, the distillate was removed at 180° C. under reduced pressure of 50 mmHg to obtain 550 parts by mass of Novolac Resin A. Furthermore, in an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device, 130 parts by mass of the above novolac resin A, 2.6 parts by mass of a 50% aqueous sodium hydroxide solution, toluene/methyl isobutyl ketone ( (Mass ratio = 2/1) 100 parts by mass was charged, the inside of the system was replaced with nitrogen while stirring, then the temperature was raised, and 45 parts by mass of ethylene oxide was gradually introduced at 150°C and 8 kg/cm ² to react. . The reaction was continued for about 4 hours until the gauge pressure reached 0.0 kg/cm ² and then cooled to room temperature. 3.3 parts by mass of a 36% hydrochloric acid aqueous solution was added to and mixed with this reaction solution to neutralize the sodium hydroxide. This neutralization reaction product was diluted with toluene, washed with water three times, and the solvent was removed by an evaporator to give a hydroxyl value of 175 g/eq. An ethylene oxide adduct of novolak resin A was obtained. In this case, 1 mol of ethylene oxide was added on average per equivalent of phenolic hydroxyl group.

175 parts by weight of the ethylene oxide adduct of novolac resin A thus obtained, 75 parts by weight of methacrylic acid, 3.0 parts by weight of p-toluenesulfonic acid, 0.1 parts by weight of hydroquinone monomethyl ether, and 130 parts by weight of toluene were mixed with a stirrer. , a thermometer, and an air blowing tube, and stirred while blowing in air to raise the temperature to 115 ° C., and distill off the water produced by the reaction as an azeotrope with toluene for another 4 hours. After reacting, it was cooled to room temperature. The resulting reaction solution was washed with a 5% NaCl aqueous solution, toluene was removed by distillation under reduced pressure, and diethylene glycol monoethyl ether acetate was added to obtain a photocurable compound solution with a solid content of 68%.

<1. Preparation of curable resin compositions of Examples 1 to 7 and Comparative Examples 1 to 4>
According to the component composition shown in Table 1 below, the materials of the curable resin compositions of Examples 1 to 7 and Comparative Examples 1 to 4 were each blended, premixed with a stirrer, and then kneaded with a three-roll mill. , to prepare each curable resin composition. In addition, the value in Table 1 is the mass part of solid content, unless there is particular notice.

Regarding each curable resin composition, as shown below, the dispersibility of the curable resin composition, the dryness to the touch of the uncured resin layer formed from the curable resin composition, and the curable resin composition The environmental reliability of the cured product (cured film) formed in was evaluated. Table 1 shows the results.

<2. Evaluation of Uniform Dispersibility>
About 1 g of each curable resin composition after preparation is placed on a metal grind gauge (groove depth 0 to 25 μm, length 24 cm), and the surface of the gauge is scraped with a metal scraper at an even speed to the lowest groove depth of 1 to 1. It took 2 seconds to pull. The grooves were observed 3 seconds after the drawing was completed, and the depth of the grooves at a portion where the total number of particles was 5 or more was confirmed. The evaluation criteria were as follows. In the case of evaluation results of ◎ or ○, the dispersibility of inorganic fillers and polymerization inhibitors, the compatibility between carboxyl group-containing resins and photocurable compounds, and the compatibility between photocurable compounds are excellent. It can be said that the uniform dispersibility of the resin composition is excellent.
◎: Less than 7.5 μm ○: 7.5 μm or more and less than 15 μm △: 15 μm or more and less than 20 μm ×: 20 μm or more

Each curable resin composition is applied to a PET film (first film , R310, 16 μm, manufactured by Nisshin Kasei Co., Ltd.) and dried horizontally in a drying oven at about 80° C. for about 20 minutes to volatilize the solvent to obtain a laminated structure having a resin layer.

<3. Evaluation of dryness to the touch>
First, an FR-4 substrate (FR-4 has a thickness of 1.6 mm and a copper foil has a thickness of 18 μm) is prepared as a copper-clad laminate, and the glossy surface is chemically polished (etched) to an equivalent of 1.0 μm. Bond CZ-8101, manufactured by MEC Co., Ltd.) and rust prevention treatment (Etching Bond CL-8300, manufactured by MEC Co., Ltd.) were performed to prepare a roughened substrate.
Next, the laminated structures of Examples and Comparative Examples were each laminated on the obtained roughened substrate using a vacuum laminator CVP-300 (manufactured by Nikko Materials Co., Ltd.) and allowed to stand until the substrate returned to room temperature. Here, the lamination temperature was 80° C., the vacuum retention time was 30 seconds, and the press time was 30 seconds.
After that, the PET film was peeled off from the resin layer of the laminated structure. The sticking state of the PET film when the PET film was peeled off was evaluated. The evaluation criteria were as follows.
◎: There is no resistance when the PET film is peeled off, and no marks remain on the surface of the resin layer. When the PET film was peeled off, there was resistance, and the surface of the resin layer was clearly marked. ×: When the PET film was peeled off, there was resistance, and the surface of the resin layer was peeled off.

<4. Evaluation of environmental reliability (peel strength after HAST)>
The environmental reliability of the cured film formed from the curable resin composition was evaluated by confirming the peel strength after a fast accelerated life test (HAST). Specifically, on the glossy surface of a 35 μm electrolytic copper foil (manufactured by Furukawa Circuit Foil Co., Ltd.), chemical polishing (CZ-8101, manufactured by MEC Co., Ltd.) was applied to an etching treatment with a surface roughness Ra equivalent to 1.0 μm. Rust treatment (Etching Bond CL-8300, manufactured by MEC Co., Ltd.) was performed. Thus, a CZ-treated copper foil substrate was obtained.

After that, the resin layers of the laminated structures of Examples and Comparative Examples were each laminated on the CZ-treated surface of the CZ-treated copper foil substrate by a vacuum laminator CVP-300 (manufactured by Nikko Materials Co., Ltd.), and the resin was laminated on the CZ-treated copper foil substrate. The layers were laminated. Here, the lamination temperature was 80° C., the vacuum retention time was 30 seconds, and the press time was 30 seconds. Then, the entire surface of the resin layer is exposed at 500 mJ/cm ² using an ultraviolet DI exposure device (Oak Manufacturing Co., Ltd., DiIMPACT Mms60, equipped with a high-pressure mercury lamp (short arc lamp)), and after peeling off the PET film, 1 wt. % sodium carbonate aqueous solution at a spray pressure of about 0.2 MPa for 60 seconds. The obtained resin layer after development was further irradiated with ultraviolet rays in a UV conveyor furnace at an exposure amount of 1000 mJ, and heated at 160° C. for 1 hour to obtain a cured film. After that, using a two-liquid adhesive (Araldite, manufactured by Huntsman Japan Co., Ltd.), a 1.6 mm FR-4 etched-out board (1.6 mm FR-4 substrate with copper foil removed from the cured film side ) were pasted together, and the adhesive was cured at room temperature to obtain a three-layer structure consisting of a CZ-treated copper foil substrate, a cured film, and an etched-out plate of FR-4. The obtained three-layer structure was cut into a size having a width of 15 mm and a length of 95 mm to prepare a test piece. In Comparative Example 2, since no cured product could be formed, the following evaluation test could not be carried out (indicated by "-" in Table 1).

A cut was made in the prepared test piece so that the CZ-treated copper foil substrate had a width of 10 mm, and the CZ-treated copper foil substrate at both ends in the width direction was removed. Then, it was treated for 96 hours in a HAST bath (HAST device: Espec Co., Ltd., highly accelerated life test device) at 130°C and 85% RH, and the cured film was heat-treated (4 hours at 175°C and 4 reflow treatments at 260°C). rice field. The test piece thus obtained was used as a "peel strength measurement test piece".
After that, JIS-C-6481-1996 copper-clad laminate test method, "5.7 peel strength" peel strength measurement method (specimen width 10 mm, 90 ° direction, speed 50 mm / min, measurement length 30 mm ), the peel strength between the cured film and the CZ-treated surface of the CZ-treated copper foil substrate was measured as shown in FIG.
In each example and comparative example, a total of five test pieces for peel strength measurement were produced, the peel strength of each was measured, and the average value was evaluated according to the following criteria.
◎: The average peel strength is 5.5 N / cm or more ○: The average peel strength is 5.0 N / cm or more and less than 5.5 N / cm ×: The average peel strength is less than 5.0 N / cm

Details of the components in Table 1 are as follows.
*1: According to Synthesis Example 1 *2: According to Synthesis Example 2 *3: Ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (manufactured by IGM Resins)
* 4: According to Synthesis Example 3, weight average molecular weight: 6,000 (by GPC measurement method)
*5: DA-600 (manufactured by Sanyo Chemical Industries, Ltd.), dipentaerythritol hexaacrylate hexafunctional acrylate product Weight average molecular weight: 578
*6: A-DCP (manufactured by Shin-Nakamura Chemical Co., Ltd.) Tricyclodecanedimethanol diacrylate Bifunctional dicyclopentadiene type acrylate Weight average molecular weight: 304
* 7: B-30 (manufactured by Sakai Chemical Industry Co., Ltd.) Barium sulfate * 8: Admafine SO-E2 (manufactured by Admatechs Co., Ltd.) Spherical silica * 9: Kinopower QS-30 (manufactured by Air Water Performance Chemicals Co., Ltd.) ) 4-Methoxy-1-naphthol *10: N-870-75EA (manufactured by DIC Corporation), bisphenol A novolac type epoxy resin *11: NC-3000H (manufactured by Nippon Kayaku Co., Ltd.), biphenyl novolac type epoxy resin * 12: Phthalocyanine blue (blue colorant)
*13: Pigment Yellow 147, anthraquinone type (yellow colorant)

As shown in Table 1, from the comparison between Examples and Comparative Examples, the curable resin composition contains (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, and (C) a photocurable compound containing no carboxyl group. , (D) an inorganic filler and (E) a polymerization inhibitor, and (C) as a photocurable compound containing no carboxyl group, (C-1) a light having a weight average molecular weight of 2,000 or more and 10,000 or less A curable compound and (C-2) a photocurable compound having a weight average molecular weight of 500 or more and less than 2,000, and (C-1) a photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less. By containing the compound in a ratio of 25 parts by mass to 500 parts by mass with respect to 1 part by mass of the polymerization inhibitor (E), the uniform dispersibility of the curable resin composition and the resin formed of the curable resin composition It was confirmed that the dryness to the touch of the layer and the environmental reliability of the cured product (cured film) of the curable resin composition were all good.

Further, from a comparison between Example 1 and Example 3, (C-3) further containing a photocurable compound having a weight average molecular weight of 100 or more and less than 500 further improves the dispersibility of the curable resin composition. I understand.

Furthermore, from the comparison between Example 1 and Examples 6 and 7, (C-3) further contains a photocurable compound having a weight average molecular weight of 100 or more and less than 500, (C-1) / (E) formulation When the ratio is 100 or more and 250 or less, the dispersibility of the curable resin composition, the dryness to the touch of the resin layer formed of the curable resin composition, and the cured product (cured film) of the curable resin composition It was found that the environmental reliability of

Claims

(A) a carboxyl group-containing resin,
(B) a photoinitiator,
(C) a photocurable compound containing no carboxyl group;
(D) an inorganic filler, and (E) a polymerization inhibitor,
A curable resin composition comprising
(C) the photocurable compound containing no carboxyl group,
(C-1) a photocurable compound having a weight average molecular weight of 2,000 or more and 10,000 or less;
(C-2) a photocurable compound having a weight average molecular weight of 500 or more and less than 2,000;
including
A curable resin composition in which the photocurable compound (C-1) is contained in an amount of 25 parts by mass or more and 500 parts by mass or less relative to 1 part by mass of the polymerization inhibitor (E).
The curable resin composition according to claim 1, wherein the (C) photocurable compound containing no carboxyl group further contains (C-3) a photocurable compound having a weight average molecular weight of 100 or more and less than 500.
The curable resin composition according to claim 1, wherein the photocurable compound (C-1) is contained in a proportion of 100 parts by mass or more and 400 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E). thing.
The curable resin composition according to claim 1, wherein the photocurable compound (C-1) is contained in a proportion of 100 parts by mass or more and 250 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E). thing.
The curable resin composition according to claim 1, wherein the photocurable compound (C-2) is contained in a proportion of 50 parts by mass or more and 500 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E). thing.
The photocurable compound (C-1) and the photocurable compound (C-2) are combined in a total amount of 75 parts by mass or more and 1000 parts by mass or less with respect to 1 part by mass of the polymerization inhibitor (E). The curable resin composition of claim 1, contained in proportions.
A laminated structure comprising a film and a resin layer provided on the film,
A laminate structure, wherein the resin layer comprises the curable resin composition according to claim 1 .
The curable resin composition according to claim 1 or a cured product obtained by curing the resin layer of the laminated structure according to claim 7.
An electronic component comprising the cured product according to claim 8.