JPH08134331A - Photo-setting resin composition and flexible solder resist ink - Google Patents

Abstract

PURPOSE: To obtain a photo-setting resin composition, containing a specific rubber-modified epoxy vinyl ester resin, a diluent, a photopolymerization initiator and an epoxy resin, useful as a flexible solder resist ink and capable of providing a resist pattern excellent in flexibility, adhesion and solder resistance. CONSTITUTION: This composition consists essentially of (A) an acid-pendant type rubber-modified epoxy vinyl ester resin prepared by reacting (i) hydroxyl groups of a rubber-modified epoxy vinyl ester resin with (ii) a polybasic acid anhydride (preferably tetrahydrophthalic anhydride, etc.), (B) a diluent (preferably a combination of a glycol derivative such as cellosolve with a petroleum-based solvent, etc.), (C) a photopolymerization initiator (preferably acetophenones) and (D) an epoxy resin (preferably having >=50 deg.C melting point). Furthermore, the component (i) is preferably obtained by reacting an epoxy resin with a rubber-like polymer containing carboxyl groups and an ethylenically unsaturated monobasic acid. For example, a polybutadiene-acrylic acid copolymer, etc., are cited as the runner-like polymer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photocurable resin composition and a resin composition for a flexible solder resist ink. More specifically, a photocurable resin composition that can be applied to permanent protective films such as overcoats, undercoats, and insulation coats for printed wiring boards, solder resist inks, etc., and to the production of printed wiring boards, especially flexible printed wiring boards. The present invention relates to a solder resist ink that can be developed with a suitable dilute alkaline solution.

[0002]

2. Description of the Related Art Recent advances in printed wiring boards have been remarkable, and in particular due to improvements in surface mounting technology, high integration of printed wiring boards is progressing at an accelerated rate. In addition to high density and high reliability, mass productivity and There is a demand for a method of forming a resist pattern that is economical. For this reason, the demand for higher density solder resist ink is more stringent, and the resolution is low with the conventional resist pattern forming method of a printed wiring board by screen printing, and it has become impossible to meet this demand. Alkali developable solder resist inks, which can be used for photographic development using high photographic methods, have been used.

Further, in recent years, flexible printed wiring boards have been widely used, and as a result, they have such flexibility that they can be applied to flexible printed wiring boards, and
There is an increasing demand for alkali-developable solder resist inks that can be used for high-resolution photographic development. A flexible and alkali-developable solder resist ink applicable to such applications has hitherto been obtained by reacting, for example, a bisphenol type epoxy resin with acrylic acid, and then adding an acid to a hydroxyl group generated by the reaction. It is known that an acid pendant type epoxy vinyl ester resin obtained by reacting an anhydride is used as a main component, and a diluent, a photopolymerization initiator, and an epoxy resin are mixed therein.

[0004]

However, the solder resist ink using the acid pendant type epoxy vinyl ester resin derived from the above bisphenol type epoxy resin as a main component has the flexibility of the cured product itself. , The adhesion to the substrate film, which is a substrate in flexible printed wiring board applications, is poor, and as a result, the flexibility of the printed wiring board itself is not yet sufficient, and the heat resistance of the cured product is inferior. In this case, the solder heat resistance is also poor.

The problems to be solved by the present invention are remarkably excellent in flexibility and heat resistance, particularly excellent in adhesion to a substrate film in flexible printed wiring board applications, and excellent flexibility and solder heat resistance. Another object of the present invention is to provide a photocurable resin composition and a flexible solder resist ink, which can be used as a flexible printed wiring board.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a specific acid pendant type rubber-modified epoxy vinyl ester resin, which contains a diluent, a photopolymerization initiator and It was found that the flexibility, adhesion and solder heat resistance can be improved by blending an epoxy resin or the like, and the present invention has been completed.

That is, the present invention provides (A) an acid pendant type rubber-modified epoxy vinyl ester resin having a structure in which a hydroxyl group of the rubber-modified epoxy vinyl ester resin is reacted with a polybasic acid anhydride, (B) a diluent, C) a photopolymerization initiator,
And (D) an epoxy resin as an essential component, a photocurable resin composition, and

(A) Acid pendant type rubber-modified epoxy vinyl ester resin having a structure in which a polybasic acid anhydride is reacted with a hydroxyl group of the rubber-modified epoxy vinyl ester resin,
The present invention relates to a flexible solder resist ink containing (B) a diluent, (C) a photopolymerization initiator, and (D) an epoxy resin as essential components.

The acid pendant type rubber-modified epoxy vinyl ester resin (A) used in the present invention may have any structure as long as it has a structure in which a hydroxyl group of the rubber-modified epoxy vinyl ester resin is reacted with a polybasic acid anhydride, and is particularly limited. However, the acid value is 30 to 140 mgKOH / g
The range of 40 to 120 mgKOH / g is particularly preferable in view of excellent solubility in an alkaline aqueous solution, excellent developability, and excellent characteristics of the resist coating film.

To obtain the acid pendant type rubber-modified epoxy vinyl ester resin (A) having the above acid value range, for example, it is obtained by reacting a rubber-modified epoxy vinyl ester resin with a polybasic acid anhydride as described above. The reaction ratio thereof is not particularly limited, and usually, the number of acid anhydride groups in the polybasic acid anhydride is 0.3 to 1.0 mol with respect to 1 mol of hydroxyl groups in the rubber-modified epoxy vinyl ester resin. The ratio is

Among them, polybasic acid anhydride (d) is added to 1 mol of the hydroxyl group in the rubber-modified epoxy vinyl ester resin from the viewpoint of good solubility in an alkaline aqueous solution, excellent developability, and excellent properties of the resist coating film. It is preferable to react both of them in a ratio such that the number of acid anhydride groups in () is 0.5 to 0.8 mol.

Here, the rubber-modified epoxy vinyl ester has a structure obtained by reacting an epoxy resin, a carboxyl group-containing rubber-like polymer and an ethylenically unsaturated monobasic acid. There is an ester bond formed by the reaction of the resin with the carboxyl group-containing rubbery polymer and the ethylenically unsaturated monobasic acid. In the present invention, among these ester bonds, the content of the ester structure site (including the rubber-like polymer portion) based on the carboxyl group-containing rubber-like polymer is
It is preferable that the acid pendant type rubber-modified epoxy vinyl ester resin (A) is contained in an amount of 3 to 60% by weight from the viewpoint of obtaining a resin excellent in flexibility, adhesion, heat resistance, electric characteristics and the like. .

In the production of this rubber-modified epoxy vinyl ester, the epoxy resin, the carboxyl group-containing rubber-like polymer and the ethylenically unsaturated monobasic acid may be reacted simultaneously, or the epoxy resin may be reacted. After the resin is reacted with the carboxyl group-containing rubbery polymer, the ethylenically unsaturated monobasic acid may be reacted.

At this time, the reaction ratio of the epoxy resin, the carboxyl group-containing rubber-like polymer and the ethylenically unsaturated monobasic acid is not particularly limited, but the carboxyl group is equivalent to one equivalent of the epoxy group of the epoxy resin. The content of the rubber-like polymer ester structure site is such that the total carboxyl groups of the group-containing rubbery polymer and the ethylenically unsaturated monobasic acid are in the range of 0.8 to 1.1 equivalents, the epoxy vinyl ester resin It is preferably 3 to 60% by weight in (A) from the viewpoint of easy preparation, and above all, the range of 0.9 to 1.0 mol is preferable from the viewpoint of obtaining a resin excellent in photocurability and storage stability.

The epoxy resin used here is not particularly limited, but for example, bisphenol type epoxy resin such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetrabromobisphenol A type epoxy resin; phenol novolac type Epoxy resin, novolak type epoxy resin such as cresol novolak type epoxy resin; 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3, Aliphatic epoxy resins such as 4-epoxycyclohexanecarboxylate, 1-epoxyethyl-3,4-epoxycyclohexane; phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, da Glycidyl esters such as mer acid glycidyl ester; tetraglycidyl diaminodiphenylmethane, triglycidyl P- aminophenol, N,
Glycidyl amines such as N-diglycidyl aniline;
Heterocyclic epoxy resins such as 1,3-diglycidyl-5,5-dimethylhydantoin and triglycidyl isocyanurate are mentioned. Among them, bisphenol type is excellent because of its excellent balance of various characteristics such as flexibility and solder heat resistance. Epoxy resins are preferred.

The structure of the carboxyl group-containing rubbery polymer is not particularly limited, but for example, an ethylenically unsaturated monobasic acid such as a polybutadiene-acrylic acid copolymer and a conjugated diene vinyl can be used. Copolymer with monomer; Copolymer of ethylenically unsaturated monobasic acid such as polybutadiene-acrylonitrile-acrylic acid copolymer, conjugated diene vinyl monomer and other vinyl monomer; structural formula 1 or structural formula 2 below. Carboxylic acid-suspended conjugated diene-based vinyl polymers such as maleated polybutadiene represented by ## STR3 ##; rubber-like polymers in which carboxyl groups are suspended on the above-mentioned molecular side chains, or carboxyl groups at both molecular ends of linear polymers A rubbery polymer having

Structural formula 1

[0018]

Embedded image

(Here, n and m represent the average number of repeating units, and each is an integer of 1 or more.)

Structural formula 2

[0021]

Embedded image (Here, n, m, and l represent the average number of repeating units, and each is an integer of 1 or more.)

Examples of the latter rubber-like polymer having a carboxyl group at both terminals of the linear polymer include, for example, a carboxyl group at both terminals of a molecule such as polybutadienedicarboxylic acid represented by the following structural formula 3. A diene vinyl polymer having: butadiene represented by the following structural formula 4
A copolymer of an ethylenically unsaturated monobasic acid such as a polymer having a carboxyl group at both terminals of an acrylonitrile copolymer and a conjugated diene vinyl monomer and having a carboxyl group at both terminals of the molecule; Examples thereof include a half ester of a conjugated diene vinyl monomer such as a copolymer of polybutadiene glycol represented by Structural Formula 5 and maleic anhydride, and an acid anhydride.

Structural formula 3

[0024]

Embedded image

(Here, n represents the average number of repeating units and is an integer of 1 or more.)

Structural formula 4

[0027]

[Chemical 4]

(Here, n and m represent the average number of repeating units, and each is an integer of 1 or more.)

Structural formula 5

[0030]

Embedded image

(Here, n represents the average number of repeating units and is an integer of 1 or more.)

Further, as the conjugated diene vinyl monomer used for the carboxyl group-containing rubber-like polymer, not only butadiene used in the above-mentioned exemplified polymers but also butadiene, isoprene, chloroprene and the like may be used. Further, the ethylenically unsaturated monobasic acid that can be copolymerized with the conjugated diene-based vinyl monomer is not limited to those listed as the above exemplified polymers, and examples thereof include (meth) acrylic acid, crotonic acid, and cinnamic acid. , Acrylic acid dimer, monomethylmalate, monopropylmalate, monobutylmalate, mono (2-ethylhexyl) malate, sorbic acid, etc., among which (meth) acrylic acid is preferred. Further, other vinyl monomers are not limited to the above exemplified compounds, and acrylic acid, methacrylic acid, acrylonitrile, styrene, vinyltoluene and the like can be used.

The number of carboxyl groups in the obtained rubbery polymer is not particularly limited, but the number of carboxyl groups per molecule is 1 to 5, more preferably 1.5 to 3 per molecule. It is desirable to be within the range.

The ethylenically unsaturated monobasic acid used in the reaction with the epoxy resin in the production of the rubber-modified epoxy vinyl ester resin is, for example, (meth) acrylic acid, crotonic acid, cinnamic acid, acrylic acid dimer. ,
Examples thereof include monomethylmalate, monopropylmalate, monobutylmalate, mono (2-ethylhexyl) malate and sorbic acid, and among them, (meth) acrylic acid is preferable.

The rubber-modified epoxy vinyl ester obtained by reacting each of the components described in detail above is not particularly limited in its structure, but it can be used in a mixed state of various structures. However, for example, a carboxyl polymer of a carboxyl group-containing rubber-like polymer having a plurality of carboxyl groups is reacted with an epoxy resin having a plurality of epoxy groups to form a rubber-like polymer ester of an epoxy resin, which remains in this compound. The epoxy group having a structure in which an ethylenically unsaturated monobasic acid is reacted is mentioned. More specifically, for example, when a rubber polymer having a carboxyl group at both molecular ends of a linear polymer is used as the carboxyl group-containing rubber polymer, and a bisphenol type epoxy resin is used as the epoxy resin. The bisphenol type epoxy resin reacts with the carboxyl groups at both ends of the rubbery polymer to form an ester structure, and the epoxy groups that remain unreacted in each bisphenol type epoxy resin part (Meta)
Examples thereof include those having a structure in which acrylic acid has reacted.

Next, the polybasic acid anhydride which reacts with the hydroxyl group of the rubber-modified epoxy vinyl ester resin to form an acid pendant structure site is not particularly limited, and examples thereof include maleic anhydride and succinic anhydride. , Itaconic anhydride, dodecyl succinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydro Phthalic anhydride, 3,4-dimethyltetrahydrophthalic anhydride, 4- (4-methyl-3-pentenyl) tetrahydrophthalic anhydride, 3-butenyl-5,6
-Dimethyltetrahydrophthalic anhydride, 3,6-endomethylene-tetrahydrophthalic anhydride, 7-methyl-
3,6-Endomethylene tetrahydrophthalic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, chlorendic anhydride, trimellitic anhydride, pyromellitic dianhydride, benzophenone tetracarboxylic acid anhydride, methylcyclohexene dicarboxylic acid Examples thereof include acid anhydrides, and among them, tetrahydrophthalic anhydride and hexahydrophthalic anhydride are preferable from the viewpoint of excellent electrolytic corrosion property.

The diluent (B) used in the present invention is the acid pendant type rubber-modified epoxy vinyl ester resin (A).
It is an indispensable constituent for forming a photopolymerizable film by dissolving it in a coating solution to obtain a viscosity suitable for various coating methods such as an electrostatic coating method and a roll coater method, and then drying it. Examples thereof include organic solvents and photopolymerizable vinyl monomers. When they are used, they may be used alone or in combination.

Examples of the organic solvent used here include aromatic hydrocarbons such as toluene and xylene; methanol,
Alcohols such as isopropyl alcohol; Esters such as ethyl acetate and butyl acetate; Ethers such as 1,4-dioxane and tetrahydrofuran; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; Glycol derivatives such as cellosolve, butyl cellosolve, and cellosolve acetate; Examples thereof include alicyclic hydrocarbons such as cyclohexanone and cyclohexanol, and petroleum solvents such as petroleum ether and petroleum naphtha. Among these, it is preferable to use the glycol derivative in combination with the petroleum-based solvent from the viewpoint of excellent workability.

Further, as the photopolymerizable vinyl monomer,
For example, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isoboronyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxydiethylene glycol. Esters of (meth) acrylic acid such as (meth) acrylate; hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate; methoxyethyl (meth ) Acrylate,
Alkoxyalkylene glycol mono (meth) acrylates such as ethoxyethyl (meth) acrylate; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di Alkylene polyol poly (meth) acrylates such as (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate; diethylene glycol di (meth) acrylate, triethylene glycol Di (meta)
Acrylate, polyethylene glycol 200 di (meth) acrylate, polyethoxylated trimethylolpropane tri (meth) acrylate, polypropoxylated trimethylolpropane tri (meth) acrylate, polyethoxylated bisphenol A di (meth) acrylate, polypropoxylated bisphenol A di (Meth) acrylate, polyethoxylated hydrogenated bisphenol A di (meth) acrylate, polypropoxylated hydrogenated bisphenol A di (meth) acrylate, polyethoxylated dicyclopentanierdi (meth) acrylate, polypropoxylated dicyclopentanieldi Polyoxyalkylene glycol poly (meth) acrylates such as (meth) acrylate; hydroxypivalic acid neopentyl glycol ester di (meth) acrylate Ester-type poly (meth) acrylates such as salts; isocyanurate-type poly (meth) acrylates such as tris [(meth) acryloxyethyl] isocyanurate; N, N-dimethylaminoethyl (meth) acrylate, N , N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate and other aminoalkyl (meth) acrylates; (meth) acrylamide, N-methyl ( (Meth) acrylamide, N, N-dimethylacrylamide, N, N-dimethyl (meth) acrylamide,
(Meth) acrylamides such as (meth) acryloylmorpholine; vinylpyrrolidone and the like. Among these, trifunctional or higher functional acrylates are preferable from the viewpoint of excellent heat resistance of the resist coating film.

The amount of the diluent (B) used is not particularly limited, but is 20 per 100 parts by weight of the acid pendant type epoxy vinyl ester resin (A).
The proportion is preferably 300 to 300 parts by weight, and more preferably 30 to 250 parts by weight.

Further, the photopolymerizable vinyl monomer promotes the photopolymerizability, and the water-soluble photopolymerizable vinyl monomer also plays a role of helping the solubility in the alkaline aqueous solution, but the photopolymerizable vinyl monomer is reduced. It is possible to form a photopolymerizable film without tack after drying, it is possible to adhere the photopolymerizable film and the resist pattern film, it is possible to improve the resolution of the resist pattern, further chemical resistance and Since the electrical characteristics are also improved, the amount of the rubber-modified epoxy vinyl ester resin (A) 100 is used.
It is preferably 50 parts by weight or less, more preferably 2 to 20 parts by weight with respect to parts by weight.

Next, the photopolymerization initiator (C) used in the present invention
Examples include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl methyl ketal, and other benzoins and their alkyl ethers; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, and 2-hydroxy. -2-methyl-1
-Phenylpropan-1-one, diethoxyacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4
Acetophenones such as-(methylthio) phenyl] -2-morpholinopropan-1-one; methylanthraquinone, 2-ethylanthraquinone, 2-tacharybutylanthraquinone, 1-chloroanthraquinone, 2
Anthraquinones such as amylanthraquinone; thioxanthones such as thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-methylthioxanthone and 2,4-diisopropylthioxanthone; acetophenone dimethyl ketal Examples thereof include benzyl dimethyl ketal and other ketals; benzophenone, 4,4-bismethylaminobenzophenone and other benzophenones, and azo compounds. Among them, acetophenones are preferable.

These can be used alone or as a mixture of two or more kinds, and further, tertiary amines such as triethanolamine and methyldiethanolamine; benzoic acids such as 2-dimethylaminoethylbenzoic acid and ethyl 4-dimethylaminobenzoate. It can be used in combination with a photoinitiating auxiliary agent such as a derivative. The amount used is 0.5 to 20 parts by weight, preferably 2 to 15 parts by weight, based on 100 parts by weight of the acid pendant epoxy vinyl ester resin (A) and the diluent (B). preferable.

The present invention provides a resin composition for a solder resist ink which is remarkably excellent in solder heat resistance and gold plating resistance by using an epoxy resin (D) as a curing component in addition to the above-mentioned components. it can.

As the epoxy resin (D) used in the present invention, any of the epoxy resins used in the above acid pendant type rubber-modified epoxy vinyl ester resin (A) can be used. Among them, the melting point is 50 ° C. or higher. The epoxy resin is preferable because it can form a photopolymerizable film without tack after drying.

The suitable range of the amount of the epoxy resin (D) used is usually 0 per epoxy group of the epoxy resin (D) per carboxyl group in the acid pendant type epoxy vinyl ester resin (A). It is a ratio of 2 to 3.0 equivalents. Above all, a ratio of 1.0 to 1.5 equivalents is preferable from the viewpoint of excellent electrical characteristics when used as a printed wiring board.

In order to accelerate the reaction between the epoxy resin (D) and the carboxyl group in the acid pendant type epoxy vinyl ester resin (A), imidazole or 3 is used.
A curing accelerator for an epoxy resin such as a primary amine or a tertiary amine salt can also be used.

Further, in the present invention, the above-mentioned acid pendant type epoxy vinyl ester resin (A), diluent (B),
For the photopolymerization initiator (C) and the epoxy resin (D),
Further, if necessary, various additives such as talc, barium sulfate, silica, clay, and other fillers; thixotropic agents such as Aerosil; phthalocyanine blue, phthalocyanine green, and titanium oxide coloring agents; silicone and fluorine leveling. Agents and defoaming agents; polymerization inhibitors such as hydroquinone and hydroquinone monomethyl ether can be added for the purpose of enhancing various properties of the solder resist ink.

The photocurable resin composition and flexible solder resist ink of the present invention thus obtained are used for screen printing, electrostatic coating, roll coater, curtain coater, etc. on a printed wiring board. Apply by
After irradiating the photopolymerizable film obtained by drying with active energy rays such as ultraviolet rays, a resist pattern is formed by removing the unexposed portion with a dilute aqueous alkali solution, and the target resist film is further post-cured by heat. Can be

[0050]

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples, but this is only one mode and the present invention is not limited thereto. All parts and% in the examples are on a weight basis.

Example 1 Bisphenol A type epoxy resin "Epiclon 850" having an epoxy equivalent of 188 [Dainippon Ink and Chemicals, Inc.]
HYC having 188 parts, a molecular weight of 3500, bound acrylonitrile 27% by weight, and 1.9 carboxyl groups / molecule.
AR CTBN1300X13 [B. F. Good
Rich Chemical Co., Ltd.] 320 parts, acrylic acid 57 parts (number of epoxy groups: total number of carboxyl groups =
1: 1) to obtain 565 parts of a rubber-modified epoxy vinyl ester resin and 91 parts of tetrahydrophthalic anhydride (the number of hydroxyl groups: the number of acid anhydride groups = 1: 0.6). Reaction was carried out in 281 parts of carbitol acetate to obtain a resin solution (A-1) containing 70% of a resin component having an acid value of 51 mgKOH / g.

A photopolymerization initiator, an organic solvent and a filler were blended together with the resin solution (A-1) as follows, and 3
The main ingredient was prepared by kneading using this roll mill. Then, an epoxy resin, an organic solvent, and a focusing agent were blended according to the following formulation, and kneaded using a three-roll to prepare a curing agent.

(Compounding) Main agent Resin solution (A-1) 50 parts 2,2-Dimethoxy-2-phenylacetophenone 5 parts Butyl cellosolve 15 parts Barium sulfate 30 parts Main agent total 100 parts

Curing agent Cresol novolac type epoxy resin "Epiclon N-673" (manufactured by Dainippon Ink and Chemicals, Inc.) 15 parts Butyl cellosolve 5 parts Barium sulfate 10 parts Curing agent total 30 parts

Next, after mixing the base material and the curing agent, the mixture is mixed with a flexible printed wiring board (Kapton 25 μm / copper foil 35 μm, line width 500) on which a circuit is formed in advance.
μm, line spacing of 500 μm) is applied to the entire surface by a screen printing method so as to have a thickness of 15 to 25 μm, and the temperature is 80 ° C.
After being dried for 20 minutes, the resist pattern film is brought into close contact with the coated surface and exposed for 60 seconds using a metal halide lamp exposure device manufactured by Oak Manufacturing Co., Ltd., and then for 60 seconds using a 1% sodium carbonate aqueous solution at a liquid temperature of 30 ° C. Development was performed, and then heat treatment was performed at 150 ° C. for 30 minutes using a hot air drier to obtain a flexible printed wiring board on which a resist pattern was formed.

Next, the results measured according to the evaluation test method shown below are shown in Table 1.

Example 2 Bisphenol A type epoxy resin "Epiclon 860" having an epoxy equivalent of 260 [Dainippon Ink and Chemicals, Inc.]
Manufactured] 260 parts, 20 parts of HYCAR CTBN1300X13, 71 parts of acrylic acid (the number of epoxy groups: the number of total carboxyl groups = 1: 1), 351 parts of rubber-modified epoxy vinyl ester resin obtained by reaction, and hexahydroanhydride 62 parts of phthalic acid (number of hydroxyl groups: number of acid anhydride groups =
1: 0.4) and butyl carbitol acetate 17
The reaction was carried out in 7 parts to obtain a resin solution (A-2) containing 70% of a resin component having an acid value of 54 mgKOH / g.

Then, after preparing the solder resist ink composition of the present invention in the same manner as in Example 1 except that the following formulation was used, a flexible printed wiring board having a resist pattern formed was obtained in the same manner. It was

(Compounding) Main agent Resin solution (A-2) 50 parts 2,2-Dimethoxy-2-phenylacetophenone 5 parts Cellosolve acetate 10 parts Pentaerythritol triacrylate 5 parts Barium sulfate 30 parts Main agent total 100 parts

Curing agent Cresol novolac type epoxy resin "Epiclon N-680" (manufactured by Dainippon Ink and Chemicals, Inc.) 15 parts Butyl cellosolve 5 parts Barium sulfate 10 parts Curing agent total 30 parts Then, according to the evaluation test method shown below. The measured results are shown in Table 1.

Example 3 475 parts of bisphenol A type epoxy resin "Epiclon 1050" (manufactured by Dainippon Ink and Chemicals, Inc.) having an epoxy equivalent of 475 and HYCAR CTBN1300X
620 parts of rubber-modified epoxy vinyl ester resin obtained by reacting 80 parts of 13 with 65 parts of acrylic acid (the number of epoxy groups: the number of total carboxyl groups = 1: 0.95), and 137 parts of tetrahydrophthalic anhydride (Number of hydroxyl groups:
The number of acid anhydride groups = 1: 0.9) was reacted with 324 parts of butyl carbitol acetate to give an acid value of 67 mg.
Resin solution containing 70% KOH / g resin (A-
3) was obtained.

Then, the solder resist ink composition of the present invention was prepared in the same manner as in Example 1 except that the following formulation was used, and then a flexible printed wiring board having a resist pattern formed thereon was obtained in the same manner. It was

(Compounding) Main agent Resin solution (A-3) 50 parts 2,2-Dimethoxy-2-phenylacetophenone 5 parts Butyl cellosolve 12 parts Dipentaerythritol hexaacrylate 3 parts Barium sulfate 30 parts Main agent total 100 parts

Curing agent "Epiclone N-680" 15 parts Butyl cellosolve 5 parts Barium sulfate 10 parts Curing agent total 30 parts Next, the results measured according to the following evaluation test method are shown in Table 1.

Example 4 180 parts of a phenol novolac type epoxy resin "Epiclon N-738" [manufactured by Dainippon Ink and Chemicals, Inc.] having an epoxy equivalent of 180 and HYCAR CTBN1300
80 parts of X13, 65 parts of acrylic acid (the number of epoxy groups:
325 parts of a rubber-modified epoxy vinyl ester resin obtained by reacting with a number of carboxyl groups = 1: 0.95 and 80 parts of succinic anhydride (number of hydroxyl groups: number of acid anhydride groups = 1: 0.8) ) And butyl carbitol acetate 1
The reaction was carried out in 73 parts to obtain a resin solution (A-4) containing 70% of a resin component having an acid value of 111 mgKOH / g.

Next, a solder resist ink composition was prepared in the same manner as in Example 1 except that the following formulation was used, and then a flexible printed wiring board having a resist pattern formed was obtained in the same manner. (Compounding) Main agent Resin solution (A-4) 50 parts 2,2-Dimethoxy-2-phenylacetophenone 5 parts Butyl cellosolve 15 parts Barium sulfate 30 parts Main agent total 100 parts Curing agent "Epiclone N-680" 15 parts Butyl cellosolve 5 parts Sulfuric acid Barium 10 parts Curing agent total 30 parts Next, the results measured according to the following evaluation test methods are shown in Table 1.

Example 5 215 parts of "Epiclone N-680" and HYCAR CT
110 parts of BN1300X13, 63 parts of acrylic acid (the number of epoxy groups: the number of total carboxyl groups = 1: 0.95)
388 parts of a rubber-modified epoxy vinyl ester resin obtained by reacting with and 70 parts of succinic anhydride (number of hydroxyl groups:
The number of acid anhydride groups = 1: 0.7) is reacted with 196 parts of butyl carbitol acetate to give an acid value of 86 mg.
Resin solution containing 70% KOH / g resin (A-
5) was obtained.

Next, a solder resist ink composition was prepared in the same manner as in Example 1 except that the following formulation was used, and then a flexible printed wiring board having a resist pattern formed was obtained in the same manner.

(Compounding) Main agent Resin solution (A-5) 50 parts 2,2-Dimethoxy-2-phenylacetophenone 5 parts Butyl cellosolve 15 parts Barium sulfate 30 parts Main agent total 100 parts Curing agent "Epiclone N-673" 15 parts Butyl cellosolve 5 parts Barium sulfate 10 parts Curing agent total 30 parts Next, Table 1 shows the results of measurement according to the following evaluation test methods.

Example 6 Bisphenol F type epoxy resin "Epiclon 830" having an epoxy equivalent of 178 [Dainippon Ink and Chemicals, Inc.]
[Production] 178 parts, 60 parts of HYCAR CTBN1300X13, 66 parts of acrylic acid (the number of epoxy groups: the number of total carboxyl groups = 1: 0.95) and 304 parts of a rubber-modified epoxy vinyl ester resin obtained by reacting 90 parts of succinic anhydride (number of hydroxyl groups: number of acid anhydride groups = 1:
0.9) was reacted with 168 parts of butyl carbitol acetate to obtain a resin solution (A-6) containing 70% of a resin component having an acid value of 128 mgKOH / g.

Then, a solder resist ink composition was prepared in the same manner as in Example 1 except that the following formulation was used, and then a flexible printed wiring board having a resist pattern formed was obtained in the same manner.

(Compounding) Main agent Resin solution (A-6) 50 parts 2,2-Dimethoxy-2-phenylacetophenone 5 parts Butyl cellosolve 15 parts Barium sulfate 30 parts Main agent total 100 parts

Curing agent "Epiclone N-680" 15 parts Butyl cellosolve 5 parts Barium sulfate 10 parts Curing agent total 30 parts Next, the results measured according to the evaluation test method shown below are shown in Table 1.

Comparative Example 1 260 parts of an epoxy vinyl ester resin obtained by reacting 188 parts of "Epiclone 850" with 72 parts of acrylic acid (the number of epoxy groups: the number of total carboxyl groups = 1: 1) and tetrahydroanhydride 91 parts of phthalic acid (the number of hydroxyl groups: the number of acid anhydride groups = 1: 0.6) are reacted in 150 parts of butyl carbitol acetate to give an acid value of 96 mgK.
Resin solution containing 70% OH / g resin (A'-
1) was obtained.

Next, a solder resist ink composition of the present invention was prepared in the same manner as in Example 1 except that the following formulation was used, and then a flexible printed wiring board having a resist pattern formed thereon was obtained in the same manner. It was

(Compounding) Main agent Resin solution (A'-1) 50 parts 2,2-Dimethoxy-2-phenylacetophenone 5 parts Butyl cellosolve 15 parts Barium sulfate 30 parts Main agent total 100 parts

Curing agent "Epiclone N-680" 15 parts Butyl cellosolve 5 parts Barium sulfate 10 parts Curing agent total 30 parts Next, the results measured according to the following evaluation test method are shown in Table 1.

Comparative Example 2 475 parts of "Epiclone 1050" and 68 parts of acrylic acid (the number of epoxy groups: the number of carboxyl groups = 1: 0.9
5) Epoxy vinyl ester resin obtained by reacting with 5) and 137 parts of tetrahydrophthalic anhydride (number of hydroxyl groups: number of acid anhydride groups = 1: 0.9) in 291 parts of carbitol acetate. And the acid value is 74
A resin solution (A'-2) containing 70% of a resin content of mgKOH / g was obtained.

Then, a comparative solder resist ink composition was prepared in the same manner as in Example 1 except that the following components were mixed, and then a flexible printed wiring board having a resist pattern formed thereon was obtained in the same manner. It was

(Compounding) Main agent Resin solution (A'-2) 50 parts 2,2-dimethoxy-2-phenylacetophenone 5 parts Petroleum naphtha 15 parts Barium sulfate 30 parts Main agent total 100 parts

Curing agent "Epiclone N-680" 15 parts Butyl cellosolve 5 parts Barium sulfate 10 parts Curing agent total 30 parts Next, the results measured according to the following evaluation test methods are shown in Table 1.

Comparative Example 3 215 parts of "Epiclone N-680" and 68 parts of acrylic acid (the number of epoxy groups: the number of total carboxyl groups = 1: 0.9
5) 283 parts of an epoxy vinyl ester resin obtained by reacting with 5) and 70 parts of succinic anhydride (the number of hydroxyl groups: the number of acid anhydride groups = 1: 0.7) in 151 parts of butyl carbitol acetate. And the acid value is 111 mgK
Resin solution containing 70% OH / g resin (A'-
3) was obtained.

Then, a solder resist ink composition was prepared in the same manner as in Example 1 except that the following formulation was used, and then a flexible printed wiring board having a resist pattern formed was obtained in the same manner.

(Compounding) Main agent Resin solution (A'-3) 50 parts 2,2-dimethoxy-2-phenylacetophenone 5 parts Butyl cellosolve 15 parts Barium sulfate 30 parts Main agent total 100 parts

Curing agent "Epiclone N-673" 15 parts Butyl cellosolve 5 parts Barium sulfate 10 parts Curing agent total 30 parts Next, the results measured according to the following evaluation test methods are shown in Table 1.

[Evaluation Test Method] Adhesion: Using a flexible printed wiring board on which a resist pattern was formed, cross-cuts were inserted in a grid pattern according to the test method of JIS D-2020, and then a peeling test was performed with cellophane tape. .

◯: No peeling was observed at 100 measuring points. Δ: Peeling was observed at 1 to 50 points out of 100 measurement points. X: Peeling was recognized at 51 to 100 points out of 100 measuring points.

Flexibility: 180 ° external folding and internal folding test (M
IT test) Judgment was made based on the number of times of bending until crack generation due to R = 4 mmφ.

Solder heat resistance: According to the test method of JIS C-6481, a flexible printed wiring board on which a resist pattern is formed is floated in a solder bath at 260 ° C. for 10 seconds. This was defined as one cycle, and after floating, the number of cycles until abnormalities such as blistering and peeling occurred in the coating film was measured.

Insulation resistance: A flexible printed wiring board on which a resist pattern was formed was applied to 24 V in an atmosphere of 60 ° C. and 90% RH, and the insulation resistance value after 400 hours was SM-10E (500 V applied by Toa Denpa Co., Ltd.). ) Was used for the measurement.

[0091]

[Table 1]

[0092]

According to the present invention, a cured product having excellent flexibility and heat resistance can be obtained. In particular, a flexible solder resist ink having excellent flexibility, adhesion and solder heat resistance can be obtained. A pattern that can be formed and that is suitable for a flexible printed wiring board that can be developed with a dilute aqueous alkaline solution is obtained.

The photocurable resin composition of the present invention can be used not only as a flexible solder resist ink but also as a permanent protective film such as an overcoat, an undercoat or an insulation coat of a printed wiring board due to the above-mentioned characteristics.

Claims (14)

[Claims] 1. An acid pendant type rubber-modified epoxy vinyl ester resin having a structure in which a hydroxyl group of a rubber-modified epoxy vinyl ester resin is reacted with a polybasic acid anhydride, (B) a diluent, and (C) a photopolymerization. Initiator, and
(D) A photocurable resin composition comprising an epoxy resin as an essential component. 2. The composition according to claim 1, wherein the rubber-modified epoxy vinyl ester resin has a structure obtained by reacting an epoxy resin with a carboxyl group-containing rubbery polymer and an ethylenically unsaturated monobasic acid. 3. The acid pendant type rubber-modified epoxy vinyl ester resin (A) has a rubber polymer ester structure site based on a carboxyl group-containing rubber polymer in the epoxy vinyl ester resin (A) of 3 to 60. The composition according to claim 1 or 2, wherein the composition is contained in a weight percentage. 4. The composition according to claim 1, 2 or 3, wherein the acid pendant type rubber-modified epoxy vinyl ester resin (A) has an acid value of 30 to 140 mgKOH / g. 5. The rubber-modified epoxy vinyl ester resin has a total of the carboxyl groups present in the carboxyl group-containing rubbery polymer and the carboxyl groups of the ethylenically unsaturated monobasic acid per equivalent of epoxy groups of the epoxy resin. The composition according to claim 4, which has been reacted at a ratio of 0.8 to 1.1 equivalents. 6. The acid-pendant type rubber-modified epoxy vinyl ester resin (A) has 0.3 to 1.0 of a hydroxyl group-free polybasic acid anhydride based on 1 mol of a hydroxyl group of the rubber-modified epoxy vinyl ester resin. The composition according to claim 5, which has a structure that is reacted at a molar ratio. 7. A structure in which a rubber-modified epoxy vinyl ester resin is obtained by reacting a bisphenol type epoxy resin with a rubber-like polymer having 1 to 5 carboxyl group-containing carboxyl groups per molecule and an ethylenically unsaturated monobasic acid. The composition according to any one of claims 1 to 6, which comprises: 8. An acid pendant type rubber-modified epoxy vinyl ester resin having a structure obtained by reacting a hydroxyl group of a rubber-modified epoxy vinyl ester resin with a polybasic acid anhydride, (B) a diluent, and (C) a photopolymerization. Initiator, and
(D) A flexible solder resist ink containing an epoxy resin as an essential component. 9. The flexibility according to claim 8, wherein the rubber-modified epoxy vinyl ester resin has a structure obtained by reacting an epoxy resin with a carboxyl group-containing rubbery polymer and an ethylenically unsaturated monobasic acid. Solder resist ink. 10. The acid pendant type rubber-modified epoxy vinyl ester resin (A) has a rubber polymer ester structure site based on a carboxyl group-containing rubber polymer in the epoxy vinyl ester resin (A) in an amount of 3 to 60. The flexible solder resist ink according to claim 8 or 9, which is contained in a weight percentage. 11. An acid pendant type rubber-modified epoxy vinyl ester resin (A) comprises 30 to 140 mgKOH / g.
The flexible solder resist ink according to claim 8, 9 or 10, which has an acid value of. 12. The rubber-modified epoxy vinyl ester resin has a total amount of the carboxyl groups present in the galboxyl group-containing rubber-like polymer and the carboxyl groups of the ethylenically unsaturated monobasic acid per equivalent of epoxy groups of the epoxy resin. The flexible solder resist ink according to claim 11, which is reacted at a ratio of 0.8 to 1.1 equivalents. 13. The acid pendant type rubber-modified epoxy vinyl ester resin (A) has 0.3 to 1.0 of a hydroxyl group-free polybasic acid anhydride with respect to 1 mol of a hydroxyl group of the rubber modified epoxy vinyl ester resin. 13. The flexible solder resist ink according to claim 12, which has a structure that is reacted at a molar ratio. 14. A rubber-modified epoxy vinyl ester resin has a structure in which a bisphenol type epoxy resin is reacted with a rubbery polymer having an average of 1 to 5 carboxyl groups and an ethylenically unsaturated monobasic acid. Claim 8
Flexible solder resist ink according to any one of items 1 to 13.