JPH10221848A - Soldering resist resin composition and its cured body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photopolymerizable compsn, having superior UV curability, heat resistance, developability with an aq. weak alkali soln. and high resolving power by incorporating specified amts. of a specified photopolymerizable prepolymer, a carboxyl group-contg. photopolymerizable monomer, an ethylene unsatd. bond-contg. monomer, a photopolymn. initiator, a heat curing agent and a diluent. SOLUTION: This photopolymerizable compsn, contains 40-80wt.% photopolymerizable prepolymer having a skeleton of novolak resin represented by the formula 10-40wt.% carboxyl group-contg. photopolymerizable monomer, 10-30wt.% ethylenic unsatd, bond-contg. monomer, 1-5wt.% photopolymn. initiator, 1-10wt.% heat curing agent and 10-50wt.% diluent. In the formula R1 is OCOCH=CH2 or CH2 OCH2 C(CCH2 OCOCH=CH2 )3 , R2 is H or CH3 and R3 is methylcyclohexene, cyclohexene, hexane, cyclohexane or vinyl.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a new and useful solder resist resin composition, and more particularly, to a photopolymerizable prepolymer having a novolak resin skeleton and a carboxyl group-containing photopolymerizable monomer. UV curability, resolution (up to 50 micrometers), rapid curability, heat resistance containing at least one ethylenically unsaturated bond-containing monomer, a photopolymerization initiator, a thermosetting agent, and a diluent as essential components A resin composition that is excellent in chemical plating resistance and electric resistance, especially suitable for the production of consumer printed wiring boards and industrial printed wiring boards, and is suitable for a solder resist developable with a dilute alkaline aqueous solution and its cured product. About.

[0002]

2. Description of the Related Art A liquid solder resist ink is generally used.
Before soldering a specific element to a printed wiring board, it is used to form a thin film on the wiring board in a region other than a portion to be soldered. This thin film is an insulating film that not only prevents the molten solder from adhering to unnecessary parts, but also serves as a protective film that prevents the circuit conductors from being oxidized and corroded by the moisture in the air. It is essential to fulfill.

[0003] Previously, solder resist inks were cured on wiring boards by ultraviolet light or heat. However, with the trend of the times, that is, the reduction in size and weight of electronic equipment and the development of surface mounting technology, higher resolution, accuracy and reliability are also required for solder resist ink, and some improvements have been made. Have been.

For example, a solder resist ink comprising a bisphenol type epoxy acrylic resin, a photosensitive agent, an epoxy resin compound, and an epoxy resin curing agent described in JP-A-50-144431 and JP-A-51-40451 is disclosed. No. However, such a solder resist ink needs to be washed away with an organic solvent to remove an unexposed area, which may cause environmental pollution and fire, and is harmful to the human body.

For this reason, many solder resist inks of the type which can be developed with a weak alkaline aqueous solution without using an organic solvent have been invented. For example, Japanese Unexamined Patent Publication No.
-40329 and JP-A-57-45785.
An essential component of this type of solder resist ink is a photopolymerizable composition obtained by further reacting polyanhydride, which is a reaction product of an epoxy resin and an unsaturated monocarboxylic acid. The liquid solder resist ink described in JP-A-61-243869 is obtained by reacting a novolak-type epoxy resin with an unsaturated monocarboxylic acid, an unsaturated monocarboxylic acid, and a polyanhydride. The solder resist ink thus obtained can withstand development in a weak acid aqueous solution and has excellent fire resistance and heat resistance. Also, U.S. Pat. No. 4,933,259 describes a photopolymerizable composition obtained by reacting a dimerization reaction product of a novolak type epoxy resin with acrylic acid with polyanhydride. . Also, in U.S. Pat. No. 5,100,767, there is disclosed a photopolymerizable polymer obtained by further reacting an ester product of a novolak type epoxy resin (melting point of 65 ° C. to 95 ° C.) with acrylic acid with polyanhydride. A composition is described wherein the thermosetting component is triglycidyl isocyanate having a melting point of 130 ° C. or less. The curing agent for the epoxy resin is s-triazine.

[0006] The liquid resist inks described in the above-mentioned patent documents are liable to be thermally cured in the pre-baking step due to the inclusion of polyanhydride, so that the development tends to be incomplete, and the polybasic acid anhydride is used. Depending on the composition, problems such as electrolytic corrosion and discoloration of the copper printed wiring board may occur. The purpose of using polybasic anhydride is to make the solder resist ink compatible with a weak alkaline developer, an epoxy resin, and an epoxy resin curing agent. Furthermore, this solder resist ink may deteriorate the electrical properties of the printed wiring board, due to the acid groups generated by the reaction of the polybasic anhydride. In addition, the heat resistance and adhesiveness of the solder resist ink were affected by the mixing ratio of the epoxy resin in use.

In addition, as a recent tendency, the density of printed wiring boards has been increasing. However, the above-mentioned liquid solder resist ink has a low resolution of only about 150 to 300 micrometers, and has a high printing density. It is no longer possible to cope with 80 micrometers to 150 micrometers required for wiring boards.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional liquid solder resist ink. That is, the present invention, as a liquid solder resist ink, has excellent ultraviolet curing ability, solder heat resistance, resistance, flexibility, adhesiveness, electrical properties, and the ability to develop with a weak alkaline aqueous solution, 50
It has a high resolution of up to micrometer and can support the required high-density printed wiring board of 80 micrometer to 150 micrometer, so that the density of high-density printed wiring board can reach the highest region. It is an object of the present invention to provide a novel photopolymerizable composition.

[0009]

Means for Solving the Problems The invention of claim 1 is:
(A) The following chemical structural formula 1 having a novolak resin skeleton
40 to 80% by weight of the photopolymerizable prepolymer shown in

The above photopolymerizable prepolymer is obtained by adding a compound (a) having at least two epoxy groups to
A monocarboxylic acid (b) having at least three ethylene bonds represented by the chemical structural formula 2, a monocarboxylic acid (c) containing at least one ethylene bond, and a saturated or unsaturated anhydride (d); A monoepoxy compound (e) having an ethylene bond is obtained by reacting the monomers in order, and (B) a carboxyl group-containing photopolymerizable monomer, which is a compound represented by the following chemical structural formula 2, is used in an amount of 10 to 10: 40% by weight,

The prepolymer (A) is thermally reacted with (C) 10 to 30% by weight of at least one monomer containing an ethylenically unsaturated bond, (D) 1 to 5% by weight of a photopolymerization initiator, and (E) a prepolymer (A). 1-10% by weight of thermosetting agent and (F) diluent 10-5
It is a photopolymerizable composition comprising 0% by weight of the above (A) to (F).

The invention of claim 2 is a compound according to claim 1, wherein R ₁ in the chemical structural formula 1 representing the photopolymerizable prepolymer (A) is OC.
OCH = CH ₂ or CH ₂ OCH ₂ C (CCH ₂ OCO
CH = CH ₂ ) ₃ and R ₂ is H or CH ₃ ;
The composition according to claim 1, wherein R ₃ is a methylcyclohexene group, a cyclohexene group, a hexane group, a cyclohexane group, or a vinyl group.

The invention of claim 3 is that the photopolymerizable prepolymer (A) has a compound (a) having at least two epoxy groups and 0.1 to 1 chemical equivalent of the epoxy group. A monocarboxylic acid (b) containing at least three ethylene bonds in a proportion of 0.5 mol;
After sequentially reacting 0.5 to 0.9 moles of an unsaturated monocarboxylic acid containing at least one ethylene bond, one equivalent of the hydroxy group obtained by the reaction of the acid with the epoxy group is added. After reacting with 0.3 to 0.6 moles of a saturated or unsaturated polybasic anhydride (d), one of the acid groups formed by the esterification reaction of the polybasic anhydride is reacted. 2. The composition according to claim 1, wherein the composition is obtained by reacting a monoepoxy compound (e) containing one ethylene bond in a ratio of 0.1 to 0.5 mol with respect to the equivalent. And

[0012] The invention of claim 4 provides a method for preparing a polymerizable prepolymer (A) represented by the chemical structural formula 1, wherein six components of K, L, M, N, O and P are present in one molecule. The following molar conditions are used: K + L + M + N + O + P = 0.9-1.1, K + L = 0.4-0.7, M + N = 0.3-0.6, O + P = 0.03-0.3, The composition according to claim 1, wherein the composition satisfies the following.

According to a fifth aspect of the present invention, the compound (a) having at least two epoxy groups is selected from the group consisting of a novolak epoxy resin, a cresol novolak epoxy resin, a halonovolak epoxy resin, a bisphenol A epoxy resin, and a bisphenol F A monocarboxylic acid (b) having at least three ethylene bonds selected from the group consisting of an epoxy resin, a triphenolmethane epoxy resin, and a tetrabromobisphenol A epoxy resin, wherein dipentaerythritol pentaacrylate or pentaerythritol triacrylate And succinic anhydride,
A monocarboxylic acid (c) selected from a reaction product of one selected from hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, and maleic anhydride and containing at least one ethylene bond (c)
Is selected from acrylic acid, methacrylic acid, crotonic acid and cinnamic acid, and a saturated or unsaturated anhydride (d) is
Monoepoxy compound (e) selected from succinic anhydride, hexahydrophthalic anhydride, methyl hexahedrophthalic anhydride, tetrahydrophthalic anhydride and maleic anhydride, and containing an ethylene bond, is selected from glycidyl acrylate or glycidyl methacrylate. A composition according to claim 1, which is selected.

According to a sixth aspect of the present invention, the carboxyl group-containing photopolymerizable monomer (B) is composed of dierythritol pentaacrylate or erythritol triacrylate, succinic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. 2. The composition according to claim 1, wherein the composition is a reactant with one selected from tetrahydrophthalic anhydride and maleic anhydride.

[0015] The invention of claim 7 is that the reaction molar ratio in the production of the carboxyl group-containing photopolymerizable monomer (B) is such that the reaction group of dipentaerythritol pentaacrylate and unsaturated polybasic anhydride has one hydroxyl group. 7. The composition according to claim 6, wherein the composition is 0.8 to 1.1 mol per unit.

[0016] The invention of claim 8 is that the at least one monomer having an ethylenically unsaturated bond (C) is 2-hydroxyethyl (meth) acrylate, ethylene glycol acrylate, dierythritol pentaacrylate and erythritol triacrylate. The composition according to claim 1, wherein the composition is at least one selected from the group consisting of:

[0017]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a photopolymerizable composition which can be developed with a weak alkaline aqueous solution and has a high resolution, comprising (A) a compound (a) having at least two epoxy groups, Reacting at least three reactants with an ethylene bond-containing monocarboxylic acid (b) represented by the chemical structural formula 2 with at least one ethylene bond-containing monocarboxylic acid (c), and then reacting with a saturated or unsaturated anhydride; A photopolymerizable prepolymer having a novolak resin skeleton represented by the following chemical structural formula 1 obtained by reacting with (d) and then reacting with an ethylene bond-containing monoepoxy compound (e) is 40 to 80% by weight. When,

(B) 10 to 40% by weight of a carboxyl group-containing photopolymerizable monomer represented by the chemical structural formula 2,

## STR2 ## (C) 10 to 30% by weight of at least one ethylenically unsaturated bond-containing monomer, (D) 1 to 5% by weight of a photopolymerization initiator, and (E) a prepolymer (A). 1-10% by weight of thermosetting agent and (F) diluent 10-5
0% by weight or more.

A feature of the present invention is that the liquid photopolymerizable prepolymer (A) is a compound having at least four ethylene bonds in a unit molecule, thereby increasing the photocuring strength of the liquid solder resist ink and improving the resolution. And the photoreaction time is increased, and the difference in solubility between exposed and unexposed areas is increased because the carboxyl group-containing photopolymerizable monomer (B) has a hydrophilic group such as a carboxyl functional group. The object is to improve the developability of the resist ink.

The liquid photopolymerizable prepolymer (A) of the present invention represented by the above chemical structural formula 1 is obtained by converting the compound (a) having at least two epoxy groups into the above-mentioned compound having at least three ethylene bonds. A reaction product of the monocarboxylic acid (b) represented by the chemical structural formula 2 is reacted with an unsaturated monocarboxylic acid (c) containing at least one ethylene bond, and then with a saturated or unsaturated polybasic anhydride (d). ) And a monoepoxy compound (e) containing one ethylene bond, followed by a continuous reaction.

Further, the monocarboxylic acid (b) represented by the chemical structural formula 2 containing at least three ethylene bonds
Is obtained by reacting dipentaerythritol pentaacrylate or pentaerythritol triacrylate with polybasic anhydride. Examples of the polybasic anhydride include dibasic acid anhydrides such as succinic anhydride, hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and maleic anhydride. Among them, it is desirable to use a reaction product of pentaerythritol triacrylate and tetrahydrophthalic anhydride.

The unsaturated monocarboxylic acid of the above-mentioned chemical structural formula 2 is not commercially available, and is obtained by reacting dipentaerythritol pentaacrylate or the like with an unsaturated polybasic anhydride. In this case, for each hydroxyl group of the dipentaerythritol pentaacrylate, 0.8
To 1.1 moles, preferably 0.9 to 1.0 moles, of the polybasic anhydride. The catalyst used includes, for example, triphenyl phosphate, triethylamine, methyltriethylammonium chloride and the like.
Among them, triphenyl phosphate is suitable. in this case,
The catalyst comprises 0.1 to 10% by weight of the total reaction mixture
It is desirable to use. During the reaction, hydroquinone, hydroquinone monomethyl ether, phenothiazine, pyrogallol, tertiary butyl catechol, etc. may be added as a polymerization inhibitor to prevent polymerization.
The amount used is from 0.01 to 1% by weight, and the reaction temperature is from 60 to 150C, preferably from 80 to 120C. A preferred range for the reaction time is 24-48 hours,
As described above, the reaction product is obtained through the chemical reaction represented by the chemical structural formula 2.

Further, examples of the unsaturated monocarboxylic acid (c) containing at least one ethylene bond include acrylic acid, methacrylic acid, crotonic acid, and cinnamic acid. Among them, acrylic acid is preferred.

Examples of the saturated or unsaturated polybasic anhydride (d) include succinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, and maleic anhydride. Preferred is tetrahydrophthalic anhydride.

Examples of the monoepoxy compound (e) containing an ethylene bond include glycidyl acrylate and glycidyl methacrylate. Among them, glycidyl acrylate is preferred.

The preferred effects can be obtained by using the respective components used in the present invention within the following ranges. Compound (a) having at least two epoxy groups
And the monocarboxylic acid (b) containing at least three ethylene bonds (Chemical Structural Formula 2), the amount of (b) used is 0.1 to 1 chemical equivalent of the epoxy group in (a). Desirably, it is 1 to 0.5 mol. In particular, it is desirably 0.3 to 0.4 mol. The amount of the unsaturated monocarboxylic acid (c) containing at least one ethylene bond is based on one chemical equivalent of the epoxy group in (a).
It is preferably 0.5 to 0.9 mol, and particularly preferably 0.6 to 0.7 mol. The amount of the saturated or unsaturated polybasic anhydride (d) used is from 0.3 to 1 chemical equivalent of the hydroxy group obtained by the reaction between the acid and the epoxy group.
The amount used is desirably 0.6 mol, and particularly preferably 0.4 to 0.6 mol. The amount of the monoepoxy compound (e) containing one ethylene bond may be one of the acid groups generated by the esterification reaction of the polybasic anhydride.
The amount used is preferably 0.1 to 0.5 mol, particularly preferably 0.2 to 0.4 mol, based on the chemical equivalent.

In other words, in one molecule of the photopolymerizable prepolymer (A), K, L, M, N, O, and P each represent a molar ratio of six components. The following conditions are satisfied. K + L + M + N + O + P = 0.9-1.1, desirably 0.95-1.05 K + L = 0.4-0.7, desirably 0.5-0.6 M + N = 0.3-0.6, Desirably, 0.4-0.5 O + P = 0.03-0.3, desirably 0.08-0.
2.

The amount of the photopolymerizable prepolymer (A) used is from 40 to 80 based on the total amount of the composition according to the present invention.
% By weight, particularly preferably 45 to 75% by weight.

Another feature of the present invention is that the carboxyl group-containing photopolymerizable monomer (B) in the solder resist resin composition of the present invention has a hydrophilic group such as a carboxyl functional group. By dissolving unexposed portions with a weak alkaline aqueous solution, a desired resist film can be formed.

The at least one ethylenically unsaturated bond-containing monomer (C) in the solder resist resin composition of the present invention can be one of well-known and commonly used photopolymerizable monomers containing an ethylene bond. Among them, 2-hydroxyethyl (meth) acrylate, ethylene glycol acrylate, pentaerythritol pentaacrylate and the like can be mentioned. The photopolymerizable monomer (B) can be used as a mixture with another monomer (C), and the mixed use amount is desirably 10 to 70%. Particularly preferably, it is 20 to 60%.

Next, typical examples of the photopolymerization initiator (D) include benzoisomethyl ether, benzoin isopropyl ether, 2,2-dimethyl-2-phenylacetophenone, 1,1-dichlorophenone, 1-hydroxy Cyclohexylphenone, 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholin-propan-1-one, N, N-dimethylacetoaminophenone, 2,4-dimethylthiooxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, acetophenone Examples include dimethyl ketal, benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, Michler's ketone, and the like. These can be used alone or in combination of two or more. A better combination is 2-methyl-1
-[4- (methylthio) phenyl] -2-morpholin-propan-1-one (Irgacure 907, manufactured by Ciba-Geigy) and 2,4-diisopropylthioxanthone (Kayacure ITX, manufactured by Nippon Kayaku Co., Ltd.). . A suitable range for the amount used is 0.5 to 1.0% by weight, based on the total amount of the reaction mixture.

As the thermosetting agent (E) for thermally reacting the photopolymerizable prepolymer (A) used in the present invention, a well-known and commonly used one such as an epoxy compound having two epoxy groups can be used. Among them, preferred representatives are triglycidyl isoanate, phenol novolak type epoxy resin, cresol novolak type epoxy resin, halophenol novolak type epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, Phenol methane epoxy resin, tetrabromobisphenol A epoxy resin, and the like. A suitable range of the amount is about 0.1 to 15 parts by weight, preferably about 0.1 part by weight, per 100 parts by weight of the photopolymerizable prepolymer (A).
The amount is 5 to 5 parts by weight.

As the diluent (F) used in the present invention, an organic solvent can be used. Representative examples thereof include propylene carbonate, butyl cellosolve, methyl carbitol, toluene, xylene, butyl carbitol, and cyclohexanone. Propylene glycol monomethyl ether, dipropylene glycol monoethyl ether and the like. The diluent (F) as described above may be used alone or 2
A combination of two or more species is used, and among them, a combination of propylene carbonate and butyl cellosolve is preferable.

The proportion of the diluent (F) used in the present invention is about 5 to 60% by weight, particularly preferably 10 to 5% by weight.
0% by weight.

The resin composition of the present invention may further contain talc, magnesium carbonate, aluminum carbonate,
An inorganic filler such as silicon oxide is added. Its use ratio is preferably 20 to 40% by weight, particularly preferably 2 to 40% by weight.
5 to 35% by weight.

[0035]

The present invention will be specifically described below with reference to examples. Unless otherwise specified, all “parts” are based on weight. -Synthesis example of unsaturated monocarboxylic acid compound (Formula 2): Synthesis example 1: dipentaerythritol pentaacrylate 524
Part (1 chemical equivalent), 152 parts (1 mol) of tetrahydrophthalic anhydride, 0.6 part of hydroquinone, and 2.6 parts of triphenylphosphine, and then heated to 80 ° C. to dissolve, and then heated at 105 ° C. for 32 hours. Reaction, 83mg / KO
A reaction product having an acid value of H / g was obtained (1 in Formula 2). Synthesis Example 2: 126 mg / KOH / of pentaerythritol pentaacrylate was replaced with 292 parts of pentaerythritol triacrylate in Synthesis Example 1
g of a reaction product having an acid value was obtained (2 in Formula 2). -Synthesis example of photopolymerizable prepolymer (A) Synthesis example 3: Cresol, novolak type epoxy resin (Y
DCN-704, manufactured by Toto Kasei Co., Ltd., softening point: 92 ° C,
Epoxy equivalent: 210) 210 parts (1 chemical equivalent) and 338 parts of unsaturated monocarboxylic acid compound (1 of formula 2) (0.
5 mol), 36 parts (0.5 mol) of acrylic acid, 0.72 part of hydroquinone, 195 parts of propylene carbonate, and 195 parts of carbitol acetate, and then heated to 80 ° C. while stirring to dissolve the reaction mixture. Then, 1.05 parts of triphenylphosphine was added and reacted at 110 ° C. for about 24 hours to obtain a reaction product having an acid value of 3 mgKOH / g. The reaction product is treated with tetrahydrophthalic anhydride 152
After adding 5 parts and reacting at 100 ° C. for 5 hours, 64 parts of glycidyl acrylate was added and reacted for 3 hours.
A reaction product (A-1) having a solid content of 65% and an acid value of 54 mgKOH / g was obtained. Synthesis Example 4: Cresol, novolak type epoxy resin (Y
DCN-704, manufactured by Toto Kasei Co., Ltd., softening point: 92 ° C,
Epoxy equivalent: 210) 210 parts (1 chemical equivalent), 196.8 parts (0.5 mol) of unsaturated monocarboxylic acid compound (1 of the formula 2), 36 parts (0.5 mol) of acrylic acid, hydroquinone 0 36 parts, 140 parts of propylene carbonate and 140 parts of carbitol acetate, and then 8 parts
The mixture was heated with stirring at 0 ° C. to dissolve the reaction mixture, and 0.85 parts of triphenylphosphine was added. The mixture was reacted at 110 ° C. for about 24 hours to obtain a reaction product having an acid value of 3 mgKOH / g. After adding 152 parts of tetrahydrophthalic anhydride to the reaction product and reacting at 100 ° C. for 5 hours, 64 parts of glycidyl acrylate was added and reacted for 3 hours.
As a result, a reaction product (A-2) having an acid value of 5 mgKOH / g and a solid content of 65% was obtained. -Comparative synthesis example of photopolymerizable prepolymer (A ') Synthesis example 5: Cresol, novolak type epoxy resin (Y
DCN-704, manufactured by Toto Kasei Co., Ltd., softening point: 92 ° C,
Epoxy equivalent: 210) 210 parts (1 chemical equivalent), dihydroxymethylpropionic acid 13.4 parts, acrylic acid 64.85 parts (0.9 mol), hydroquinone 0.46
, 140 parts of propylene carbonate, and 161.59 parts of carbitol acetate were mixed and heated while stirring at 90 ° C. to dissolve the reaction mixture. After cooling to 60 ° C., 1.38 parts of triphenylphosphine was added. In addition, the reaction was carried out at 100 ° C. for 32 hours to obtain a reaction product having an acid value of 0.5 mg KOH / g (hydroxy value: 1.2 equivalent). 36.47 parts of tetrahydrophthalic anhydride (0.
24 mol) and 19.63 parts of carbitol acetate, and reacted at 90 ° C. for 6 hours to obtain a solid content of 65% and 40%.
Unsaturated reaction product (A'-1) having an acid value of mgKOH / g
I got Synthesis Example 6: Cresol, novolak type epoxy resin (Y
DCN-704, manufactured by Toto Kasei Co., Ltd., softening point: 92 ° C,
Epoxy equivalent: 210) 210 parts (1 chemical equivalent), acrylic acid 72 parts (1 mol), hydroquinone 0.46
And 161.59 parts of carbitol acetate were mixed and heated with stirring at 90 ° C. to dissolve the reaction mixture, then cooled to 60 ° C., and triphenylphosphine was added.
38 parts were added and reacted at 100 ° C. for 12 hours.
The reaction product with an acid number of mg KOH / g (hydroxy number:
1.2 equivalents). To this reaction product, 76 parts (0.5 mol) of tetrahydrophthalic anhydride and 19.63 parts of carbitol acetate were added and reacted at 95 ° C. for 6 hours to give a solid content of 65% and an acid value of 40 mg KOH / g. A saturated reaction product (A'-2) was obtained. Synthesis Example 7: Cresol, novolak type epoxy resin (softening point: 74 to 83 ° C., epoxy equivalent: 215) 215 parts (1 chemical equivalent), acrylic acid 72 parts (1 mol), hydroquinone 0.46 part, and butyl cellosol 155.
6 parts were mixed and heated to 90 ° C. with stirring to dissolve the reaction mixture. After cooling to 60 ° C., 1.38 parts of triphenylphosphine was added, and the mixture was reacted at 100 ° C. for 8 hours and reacted at 3 mg KOH / g of reaction product with an acid number were obtained. 76 parts of tetrahydrophthalic anhydride (0.5 part
Mol) and 19.63 parts of carbitol acetate, and reacted at 95 ° C. for about 6 hours to obtain a solid content of 65%.
A reaction product (A′-3) having an acid value of 54 mgKOH / g was obtained. Synthesis Example 8: 100 parts of cresol, novolak type epoxy resin (softening point: 85 ° C., epoxy equivalent: 212) (0.
47 chemical equivalents) and 71.3 parts of acrylic acid dimer (0.
49 mol), 0.46 parts of hydroquinone, and 103.6 parts of carbitol acetate, and the mixture was heated with stirring at 90 ° C. to dissolve the reaction mixture, and then cooled to 60 ° C., and triphenylphosphine was added. Add 38 parts and add 1
The reaction was carried out at 00 ° C. for 8 hours to obtain a reaction product having an acid value of 3 mgKOH / g. To this reaction product, 70.4 parts (0.46 mol) of tetrahydrophthalic anhydride was added and reacted at 95 ° C. for about 6 hours, whereby the solid content was 70%, 54 mg KOH
/ G of reaction product (A'-4). Synthesis Example 9: Cresol, novolak type epoxy resin (softening point: 85 ° C., epoxy equivalent: 215), 215 parts (1 chemical equivalent), acrylic acid 72 parts (1 mol), hydroquinone 0.5 part, and carbitol acetate 103.6
The mixture was heated while stirring at 90 ° C. to dissolve the reaction mixture, cooled to 60 ° C., added with 1.38 parts of triphenylphosphine, reacted at 100 ° C. for about 8 hours, and reacted at 3 mg KOH / g of reaction product with an acid number were obtained. 116 parts of hexahydrophthalic anhydride (0.1 part) was added to the reaction product.
75 mol) and allowed to react at 95 ° C. for about 6 hours,
A reaction product intermediate having a solid content of 70% and an acid value of 72 mgKOH / g was obtained. To this reaction product intermediate, 22 parts (0.26 mol) of ketene was added, and the mixture was maintained at 50 ° C., and after about 30 minutes, And heated to 80 ° C. to cause a reaction.
Thus, a reaction product (A′-5) having an acid value of g and a hydroxy value of 1.9 mg KOH / g was obtained. Examples: The present invention can be more clearly illustrated by the following examples, but the present invention is not limited to the following examples. The composition shown in Tables 1 and 2 below was kneaded by a test roll (roll mill) to prepare a solder resist ink composition. The amount used in the table is weight. This composition is applied to the entire surface of the copper-clad laminate and the printed wiring board on which a pattern has been formed by etching in advance to a thickness of 20 to 30 micrometers by a screen printing method. Dry at 80 ° C. for 30 minutes, then apply the negative film in direct contact with the coating. Next, ultraviolet rays were irradiated by a parallel exposure device (HMW-680GW type, manufactured by Oak Manufacturing Co., Ltd.) having an illuminance of 25 mW / cm ² , and then about 2.0 kgf / cm using a 1% aqueous sodium carbonate solution as a developing solution.
^The unirradiated part is dissolved and removed by the spray pressure of ² . In order to improve the heat resistance after exposure curing, it is further 100 to 200.
C. for 0.5 to 1 hour to obtain a completely cured coating film.

[Table 1]

[Table 2] For each of the test pieces prepared in Examples 1 to 8 and Comparative Examples 1 to 8 in the table, before developing, after confirming the drying with a finger, the resist film was directly adhered to the test piece, and then thermosetting. Before the development, the photocurability and photosensitivity of the resist film of the developed test piece were evaluated. The adhesiveness of the resist film of the test piece after thermosetting, solder heat resistance,
Gold plating resistance, acid resistance, alkali resistance, solvent resistance and pencil hardness were evaluated. The results are shown in Table 3 below.

[Table 3] Dryness to the touch: 25% at 65 ° C for each test piece
After being left in a constant temperature and humidity room of RH for 1 hour, the tack of the coating film was judged and evaluated with a finger.・ ・ ・: No tack was observed at all △: Slight tack was observed x: Ink adhered to the finger Developability: Each test piece was sprayed with a 1% aqueous sodium carbonate solution The developability when developing at a pressure of 2.0 kg / cm ² for 1 minute was visually determined with a microscope. ◎ ・ ・ ・ Thin which could be completely developed to fine parts ○ ・ ・ ・ There is a part which cannot be developed thinly on the substrate surface △ ・ ・ ・ There is a considerable part which cannot be developed x ・ ・ ・ Thin which has not been developed Adhesion: According to the test method of JIS D-0202, cross-cut each test piece in a grid pattern,
Next, the state of peeling after the peeling test with a cellophane tape was visually determined. ◎: 100/100 with no change observed ○: 100/100 with slight peeling of the wire △: 50/100 to 90/100 x: 0/100 ５０50/100 Solder heat resistance: According to the test method of JIS C-6481, the state of the coating film after each test piece was immersed in molten solder at 260 ° C. for 10 seconds was determined.・ ・ ・: No abnormality in appearance of coating film も の: Change in color of coating film was observed x: Flooding, melting, and peeling of coating film Gold plating resistance: JIS C-6481 According to the test method, each test piece is immersed in an acidic degreasing solution at 30 ° C. for 3 minutes, and then immersed in water for 3 minutes. Next, the test piece is immersed in a 14.3% by weight aqueous solution of ammonium persulfate at room temperature for 3 minutes, and further immersed in a 10% by volume aqueous solution of sulfuric acid at room temperature for 1 minute, and is immersed in water for about half an hour. Soak for 1 minute. Then, after immersing each test piece in a catalyst solution at 30 ° C. for 7 minutes,
Immerse in water for 3 minutes. Further, nickel plating was performed for 20 minutes using a nickel plating solution at 85 ° C. Each test piece was immersed in a 10% by volume sulfuric acid aqueous solution at room temperature for 1 minute, immersed in running water for about half to 1 minute to rinse, and then each test piece was immersed in a nickel plating solution at 95 ° C for 10 minutes. After proceeding with nickel plating for 3 minutes, it is immersed in running water for 3 minutes, rinsed, rinsed thoroughly with water, and dried completely. A peeling test was performed on the coating film attached to each test piece using a cellophane tape, and the degree of peeling of the coating film was visually determined.・ ・ ・: Not peeled off at all △: slightly peeled off x: completely peeled off Photosensitivity: energy difference in one step is 0.15
The energy difference of the step wedge was visually determined for the test piece of the step wedge having (expressed by Δlog E) in the same manner as in the development test. The higher the step energy, the higher the photosensitivity. Pencil hardness: Indicated with the highest hardness that would not damage the film when a load of 1 kg was applied using a pencil hardness tester according to the test method of JIS K-5400. The pencil used was "Mitsubishi High Uni" (manufactured by Mitsubishi Pencil Co., Ltd.). Acid resistance: Each test piece was immersed in a 10% by volume aqueous sulfuric acid solution at 20 ° C. for 30 minutes in the same manner as in the adhesion test, and the state and adhesion of the coating film were comprehensively determined and evaluated. . ◎ ・ ・ ・ No change observed ○ ・ ・ ・ Small change △ ・ ・ ・ Notable change x ・ ・ ・ Coating swelled and dropped Alkali resistance: Each In a 10% by volume aqueous sodium hydroxide solution in the same manner as in the adhesion test,
After immersion at 20 ° C. for 30 minutes, the state and adhesion of the coating film were comprehensively determined and evaluated.・ ・ ・: No change observed ○: slight change △: noticeable change x: coating film swelled and dropped Solvent resistance: Each test piece was immersed in chloroform and acetone at 20 ° C. for 30 minutes in the same manner as in the adhesion test, and the state and adhesion of the coating film were comprehensively determined and evaluated. ◎ ・ ・ ・ No change is observed ○ ・ ・ ・ Slight change △ ・ ・ ・ Notable change x ・ ・ ・ Coating swells and falls off Resolution (degree) : Make each test piece the same as in the adhesion test. A tool microscope (magnification: 10)
0) was used to determine the line width of the resist. The smaller the numerical value, the finer the resolution of the resist, and the wider its application range.

[0036]

As described above, the carboxyl group-containing photopolymerizable monomer (shown in the chemical structural formula 2) in the resist ink composition according to the present invention, and the photopolymerizable prepolymer synthesized therefrom ( A) plays an important role. As is clear from the above Examples, the ink composition of the present invention that can be developed with a weakly alkaline aqueous solution has a carboxyl group of a photopolymerizable monomer having a carboxyl group (Chemical Structural Formula 2). The difference in compatibility between the unexposed portion and the weakly exposed aqueous solution increases, and in particular, the resolution can be improved. In addition, the photopolymerizable prepolymer A is excellent in solder heat resistance and plating resistance by improving the intensity of curing by light, can improve resolution, and can accelerate photoreaction time.

Claims (8)

[Claims] (A) 40 to 80% by weight of a photopolymerizable prepolymer having a novolak resin skeleton and represented by the following chemical structural formula 1; The photopolymerizable prepolymer is obtained by adding a compound (a) having at least two or more epoxy groups to a monocarboxylic acid (b) having at least three ethylene bonds represented by the chemical structural formula 2 and at least one A monocarboxylic acid (c) containing two ethylene bonds, a saturated or unsaturated anhydride (d), and a monoepoxy compound (e) containing an ethylene bond are sequentially reacted, B) A carboxyl group-containing photopolymerizable monomer, which is a compound represented by the following chemical structural formula 2, is
40% by weight (C) 10 to 30% by weight of at least one monomer containing an ethylenically unsaturated bond, (D) 1 to 5% by weight of a photopolymerization initiator, and (E) a thermosetting agent for thermally reacting the prepolymer (A) 1 A photopolymerizable composition comprising (A) to (F), 10 to 10% by weight and (F) 10 to 50% by weight of a diluent. 2. The photopolymerizable prepolymer (A) wherein R ₁ in the chemical formula ₁ is OCOCHＣＨCH ₂ or CH ₂ OCH ₂ C (CCH ₂ OCOCH ＝ CH ₂ ) _3.
The composition according to claim 1, wherein R ₂ is H or CH ₃ , and R ₃ is a methylcyclohexene group, a cyclohexene group, a hexane group, a cyclohexane group, or a vinyl group. 3. The photopolymerizable prepolymer (A)
Is a compound (a) having at least two epoxy groups
And 0.1 for each chemical equivalent of the epoxy group.
A monocarboxylic acid (b) containing at least three ethylene bonds in a proportion of 1 to 0.5 mol and an unsaturated monocarboxylic acid containing at least one ethylene bond in a proportion of 0.5 to 0.9 mol; Are reacted in that order, and then a saturated or unsaturated polybasic anhydride (d) in a ratio of 0.3 to 0.6 mol per 1 chemical equivalent of the hydroxy group obtained by the reaction between the acid and the epoxy group. And a monoepoxy compound containing one ethylene bond in a ratio of 0.1 to 0.5 mol per 1 chemical equivalent of an acid group generated by the esterification reaction of the polybasic anhydride. The composition according to claim 1, wherein (e) is reacted. 4. In one molecule of the photopolymerizable prepolymer (A) represented by the chemical structural formula 1, K, L, M,
The molar ratios of the six components N, O, and P are as follows: K + L + M + N + O + P = 0.9 to 1.1, K + L = 0.4 to 0.7, M + N = 0.3 to 0.6, The composition according to claim 1, wherein O + P = 0.03 to 0.3 is satisfied. 5. The compound (a) having at least two epoxy groups is a novolak type epoxy resin, cresol.
Novolak type epoxy resin, halo novolak type epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, triphenol methane epoxy resin,
And a monocarboxylic acid (b) having at least three ethylene bonds is selected from dipentaerythritol pentaacrylate or pentaerythritol triacrylate, succinic anhydride, and hexahydrophthalic anhydride. acid,
A monocarboxylic acid (c) containing at least one ethylene bond selected from a reactant selected from methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, and maleic anhydride; and acrylic acid, methacrylic acid Acid, crotonic acid, cinnamic acid, and saturated or unsaturated acid (d) selected from succinic anhydride, hexahydrophthalic anhydride, methyl hexahedrophthalic anhydride, tetrahydrophthalic anhydride and maleic anhydride And a monoepoxy compound containing an ethylene bond (e)
The composition of claim 1, wherein the is selected from glycidyl acrylate or glycidyl methacrylate. 6. A carboxyl group-containing photopolymerizable monomer (B) comprising: dierythritol pentaacrylate or erythritol triacrylate, succinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and tetrahydrophthalic anhydride. The composition of claim 1, wherein the composition is a reactant with one selected from maleic anhydride. 7. The reaction molar ratio in the production of the carboxyl group-containing photopolymerizable monomer (B) is 0.8 to 0.8 per hydroxyl group of a reaction product of dipentaerythritol pentaacrylate and unsaturated polybasic anhydride. 7. The composition of claim 6, wherein the composition is from 0.1 to 1.1 moles. 8. The at least one monomer (C) containing an ethylenically unsaturated bond is selected from the group consisting of 2-hydroxyethyl (meth) acrylate, ethylene glycol acrylate, dierythritol pentaacrylate and erythritol triacrylate. At least one of
The composition according to claim 1.