JPH1121327A - Photocurable resin and solder photoresist ink composition containing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable resin developable with a dilute alkali that has a markedly improved photocurability and is cured by a small amount of ultraviolet exposure to yield a film having a good performance, and a solder photoresist ink composition containing this resin. SOLUTION: The photocurable resin has a radical-polymerizable unsaturated acyl group and a carboxyl group which are obtained by reacting the compound obtained by reacting an epoxy resin with from 0.5 to 50 mol.% monocarboxylic acid having two or more acryloyl groups per molecule and 50 to 99.5 mol.% acrylic acid or methacrylic acid, with a dibasic acid anhydride. A solder photoresist ink composition is obtained by blending a photopolymerization initiator, a diluent and a thermosetting resin with this photocurable resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photocurable resin and a solder photoresist ink composition containing the resin. More specifically, the present invention is useful as a solder photoresist ink composition as a permanent protective coating in the production of printed wiring boards and a photoresist ink composition for copper etching. The present invention relates to a photocurable resin capable of obtaining a coating film having the following formula, which can be developed with a dilute alkali, and a solder photoresist ink composition containing the resin.

[0002]

2. Description of the Related Art At present, a dilute alkali developing type liquid solder photoresist ink is widely used as a solder resist for various printed wiring boards. Further, when manufacturing a printed wiring board, a photoresist ink for liquid copper etching of a dilute alkali development type is used for the purpose of forming a copper foil circuit pattern. For example, Japanese Patent Publication No. 1-54390 discloses a novolak-type epoxy compound as a liquid resist ink composition which is excellent in photocurability, heat curability, heat resistance, solvent resistance, acid resistance and the like, and can be developed with an alkaline aqueous solution. Composition comprising an active energy ray-curable resin obtained by reacting a reactant of carboxylic acid and an unsaturated monocarboxylic acid with a polybasic acid anhydride, a photopolymerization initiator, a diluent and an epoxy compound Things have been suggested. However, photoresist inks based on such resins have the disadvantage of low photocurability.
Regarding the solder photoresist ink, in recent years, it has become necessary to shorten the manufacturing time to reduce the manufacturing cost, and the speed of the manufacturing line is increasing. For this reason, the exposure time by ultraviolet rays is reduced, and the exposure amount itself is reduced. Further, with respect to the photoresist ink for copper etching, although there is an advantage that the resolution is high as compared with the existing dry film, it has become clear that the photosensitivity is considerably low. JP-A-6-166843
In the publication, the resin is easily cured by a slight photopolymerization reaction, and as a resin with a high probability of three-dimensionalization and improved light sensitivity, a novolak epoxy resin having four or more nuclei is (meta)
Photopolymerizable resin obtained by reacting acrylic acid to introduce a (meth) acryloyl group and increasing the molecular weight using a chain extender having two or more functional groups capable of reacting with a hydroxyl group generated by this reaction A photocurable ink composition for a liquid solder resist containing a photopolymerization initiator and a diluent has been proposed. Also, JP-A-6-258830 discloses that a pattern can be formed even at a low exposure dose.
As a resist ink composition excellent in resolution and solvent resistance, and also excellent in dispersion stability of the composition itself, ethylene oxide adduct or glycerin ester of (meth) acrylic acid, glycidyl (meth) acrylate and other ethylene UV-curable resin obtained by reacting (meth) acrylic acid and polybasic anhydride with copolymer of unsaturated monomer, containing photopolymerization initiator, diluent and thermosetting epoxy compound Compositions have been proposed. Further, Japanese Patent Application Laid-Open No. Hei 6-3
No. 01206, as a photosensitive resin composition having a good adhesive strength to copper and a good thin wire retention, a compound obtained by adding ethyl isocyanate (meth) acrylate to an alcohol obtained by chain-extending bisphenol with a polyalkylene glycol. There has been proposed a composition containing an ethylenically unsaturated compound, a carboxyl group-containing polymer compound and a photoinitiator. However, each of these compositions significantly increases the molecular weight of the photocurable resin,
It promotes cross-linking and gelling of the resin.Because the molecular weight of the resin is high, the viscosity increases when applied and processed in photoresist inks, etc. Reduces storage stability.

[0003]

SUMMARY OF THE INVENTION According to the present invention, there is provided a photocurable composition which has a remarkably improved photocurability, is cured with a small amount of ultraviolet light exposure, has excellent performance, and can be developed with a dilute alkali. The present invention has been made for the purpose of providing a conductive resin and a solder photoresist ink composition containing the resin.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that epoxy resin
Radical polymerizable unsaturated acyl obtained by reacting a dicarboxylic anhydride with a compound obtained by reacting a monocarboxylic acid having two or more acryloyl groups in one molecule with acrylic acid or methacrylic acid. A resin having a group and a carboxyl group is excellent in dilute alkali developability and heat resistance, and has a very good photocurability as compared with a conventional resin, and based on this finding, completes the present invention. Reached. That is, the present invention provides (1) an epoxy resin containing 0.5 to 50 mol% of a monocarboxylic acid having two or more acryloyl groups in one molecule and 50 to 99.5 mol% of acrylic acid or methacrylic acid. A photocurable resin having a radically polymerizable unsaturated acyl group and a carboxyl group obtained by further reacting a dibasic acid anhydride with the compound obtained by the reaction, and (2)
(1) The photocurable resin (A) according to the above, a photopolymerization initiator (B),
A solder photoresist ink composition comprising a diluent (C) and a thermosetting resin (D). Further, as a preferred embodiment of the present invention, the light according to (1), wherein (3) the epoxy resin is a bisphenol A type epoxy resin, a bisphenol A novolak type epoxy resin, a phenol novolak type epoxy resin or a cresol novolak type epoxy resin. (4) The total amount of a monocarboxylic acid having two or more acryloyl groups in one molecule and acrylic acid or methacrylic acid is not more than 0.1% of the epoxy group of the epoxy resin.
The photocurable resin according to item (1), which is 9 to 1.1 mole times,
(5) The amount of dibasic acid anhydride is 0.1% of the total amount of monocarboxylic acid having two or more acryloyl groups in one molecule reacted with the epoxy resin and acrylic acid or methacrylic acid.
The photocurable resin according to item (1), which is 3 to 1.0 mole times,
(6) The photocurable resin according to item (1) having an acid value of 60 to 140 mgKOH / g, and (7) the photopolymerization initiator of component (B) is compounded with the photocurable component (A). The solder photoresist ink composition according to item (2), wherein the amount is 0.2 to 20 parts by weight per 100 parts by weight of the conductive resin, wherein the diluent of the component (8) (C) is:
At least one selected from the group consisting of a photopolymerizable monomer and an organic solvent, the amount of which is 30 to 200 parts by weight per 100 parts by weight of the photocurable resin of the component (A);
Item solder photoresist ink composition, and,
(9) The thermosetting resin of the component (D) is a bifunctional or higher functional epoxy resin, and the compounding amount thereof is 5 to 60 parts by weight per 100 parts by weight of the photocurable resin of the component (A). The solder photoresist ink composition described in the item 2) can be used.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The photo-curable resin of the present invention is prepared by adding 0.5 to 50 mol% of a monocarboxylic acid having two or more acryloyl groups in one molecule to acrylic resin or methacrylic acid 50 to an epoxy resin. A resin having a radically polymerizable unsaturated acyl group and a carboxyl group obtained by reacting a compound obtained by reacting 〜99.5 mol% with a dibasic acid anhydride. The epoxy resin used in the present invention is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type Epoxy resins, cycloaliphatic epoxy resins, glycidyl ester resins, glycidylamine resins, heterocyclic epoxy resins and the like can be mentioned. Among these, bisphenol A type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin and bisphenol A novolak type epoxy resin can be particularly preferably used. The softening point of the epoxy resin used is
Preferably it is 60 ° C. or higher. In the present invention, one epoxy resin can be used alone, or two or more epoxy resins can be used in combination.

In the present invention, a monocarboxylic acid having two or more acryloyl groups in one molecule and acrylic acid or methacrylic acid are reacted with an oxirane ring of an epoxy resin. There is no particular limitation on the monocarboxylic acid having two or more acryloyl groups in one molecule. For example, a pentaerythritol triacrylate / succinic anhydride adduct represented by the formula [1] or a carboxylic acid represented by the formula [2] Dipentaerythritol pentaacrylate / tetrahydrophthalic anhydride adduct, isocyanuric acid ethylene oxide 3 mole adduct diacrylate / succinic anhydride adduct represented by formula [3], pentaerythritol triacrylate represented by formula [4] -Tetrahydrophthalic anhydride adduct, pentaerythritol triacrylate-phthalic anhydride adduct, dipentaerythritol pentaacrylate-succinic anhydride adduct, etc. can be mentioned. In the present invention, one kind of monocarboxylic acid having two or more acryloyl groups in one molecule can be used alone,
Alternatively, two or more kinds can be used in combination.

Embedded image

Embedded image Such a monocarboxylic acid having two or more acryloyl groups in one molecule is obtained by reacting a monoalcohol having two or more acryloyl groups in one molecule with a dibasic acid anhydride in an equivalent amount. It can be easily obtained by forming an ester.

The molar ratio of the carboxylic acid to be reacted with the epoxy resin is 0.5 to 50 mol% of a monocarboxylic acid having two or more acryloyl groups in one molecule and 50 to 99.5 mol of acrylic acid or methacrylic acid. %. When the amount of acrylic acid or methacrylic acid is less than 50 mol%, the reactivity between the epoxy resin and the carboxylic acid decreases during the reaction with the epoxy resin, and the unreacted carboxylic acid, Or unreacted epoxy groups remain,
There is a possibility that storage stability and heat resistance as a solder photoresist ink may be reduced. When the amount of acrylic acid or methacrylic acid exceeds 99.5 mol%, the photocurability of the synthesized photocurable resin can be improved without using a monocarboxylic acid having two or more acryloyl groups in one molecule.
There is a possibility that there is little improvement compared to a resin synthesized using only acrylic acid or methacrylic acid. In the present invention, the order in which the epoxy resin is reacted with a monocarboxylic acid having two or more acryloyl groups in one molecule and acrylic acid or methacrylic acid is not particularly limited,
For example, a monocarboxylic acid having two or more acryloyl groups in one molecule and acrylic acid or methacrylic acid can be simultaneously added to an epoxy resin and reacted, and a monocarboxylic acid having two or more acryloyl groups in one molecule can be reacted. A carboxylic acid and either acrylic acid or methacrylic acid can be added to an epoxy resin and reacted, and then the other can be added and reacted, or a monocarboxylic acid having two or more acryloyl groups in one molecule. While changing the mixing ratio of the mixture of acid and acrylic acid or methacrylic acid, it can be added to the epoxy resin continuously and reacted. In the present invention, the amount of carboxylic acid reacted with the epoxy resin, that is, the total amount of monocarboxylic acid having two or more acryloyl groups in one molecule and acrylic acid or methacrylic acid, the amount of carboxyl group is the amount of epoxy group 0.9 ~
It is preferably 1.1 mole times. When the amount of the carboxyl group is less than 0.9 times the amount of the epoxy group, the synthesis reaction may not proceed normally. When the amount of the carboxyl group exceeds 1.1 mol% of the amount of the epoxy group, the heat resistance and the chemical resistance of the cured product of the solder photoresist ink composition may be reduced.

In the present invention, a reaction diluent can be used in the reaction between the epoxy resin and the carboxylic acid. As the reaction diluent, a photopolymerizable monomer or an organic solvent can be used. Examples of the photopolymerizable monomer that can be used as a reaction diluent include, for example, methyl
(Meth) acrylate, ethyl (meth) acrylate, n-
Propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-ethoxy Ethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate,
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, benzyl (meth) acrylate, ethylene glycol mono (meth) acrylate, monofunctional acrylate compounds such as ethyl carbitol (meth) acrylate, ethylene glycol di ( (Meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate,
Trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) Examples include acrylates and polyfunctional acrylates such as polyfunctional epoxy acrylates. In addition, (meth) acrylate indicates both acrylate and methacrylate.

Examples of the organic solvent that can be used as the reaction diluent include ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol and cyclohexanol, cyclohexane, and the like.
Alicyclic hydrocarbons such as methylcyclohexane, petroleum solvents such as petroleum ether, petroleum naphtha, cellosolves such as cellosolve and butyl cellosolve, carbitols such as carbitol and butyl carbitol, ethyl acetate,
Examples thereof include acetates such as butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, and the like. In the present invention, one type of reaction diluent can be used alone, or two or more types can be used in combination. Preferably, the reaction diluent is added in an amount of 20 to 50% by weight based on the total weight of the reaction mixture. In the present invention, the reaction between the epoxy resin and the monocarboxylic acid is preferably performed at 100 to 120 ° C. When the reaction temperature is lower than 100 ° C., the reaction rate is low, and the reaction may take a long time. Reaction temperature is 1
When the temperature exceeds 20 ° C., the unsaturated carboxylic acid causes thermal polymerization,
Gelation may occur during the reaction.

In the present invention, a dibasic anhydride is further added to a reaction product obtained by reacting an epoxy resin with a monocarboxylic acid having two or more acryloyl groups in one molecule and acrylic acid or methacrylic acid. Let react. The reaction product of the epoxy resin and the carboxylic acid can be subjected to a reaction with a dibasic acid anhydride without isolation, as a reaction diluent solution. The dibasic acid anhydride to be reacted is not particularly limited, and either a saturated dibasic acid anhydride or an unsaturated dibasic acid anhydride can be used. Such dibasic anhydrides include, for example, succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endmethylene Examples thereof include tetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, and chlorendic anhydride. Among them, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride can be particularly preferably used.
In the present invention, one type of dibasic acid anhydride can be used alone, or two or more types can be used in combination.

The dibasic acid anhydride reacts with a hydroxyl group formed by the reaction between the epoxy resin and the carboxylic acid,
Generates ester bonds and free carboxyl groups. The amount of the dibasic acid anhydride to be reacted is preferably 0.3 to 1.0 times the carboxylic acid reacted with the epoxy resin. In the epoxy resin, in addition to the generation of an equivalent number of hydroxyl groups equal to the number of moles of the reacted carboxylic acid, the hydroxyl groups originally contained in the epoxy resin are present. 0.3- of carboxylic acid reacted with epoxy resin
By reacting the dibasic acid anhydride at a molar ratio of 1.0, a part of the hydroxyl groups of the resin can be left as it is, and the remaining hydroxyl groups can be esterified. When the amount of the dibasic acid anhydride to be reacted is less than 0.3 mole times the carboxylic acid reacted with the epoxy resin, the dilute alkali developability of the solder photoresist ink composition may be reduced. If the amount of the dibasic acid anhydride to be reacted exceeds 1.0 mol times of the carboxylic acid reacted with the epoxy resin, unreacted dibasic acid anhydride remains in the photocurable resin and the storage stability In addition, when a thermosetting resin, which is one of the ink components as a solder photoresist ink, is blended, there is a possibility of adverse effects such as thickening and gelling. In the present invention, a dibasic acid anhydride is added to a reaction product of an epoxy resin and a carboxylic acid to cause a reaction. When the reaction product is present as a solution of a reaction diluent, the reaction can be advanced by adding and dissolving a dibasic acid anhydride to the solution and heating. The reaction temperature is preferably from 70 to 100 ° C. A resin obtained by reacting a reaction product of an epoxy resin and a carboxylic acid with a dibasic acid anhydride has an acid value of 60 to 140 mgKOH / g.
It is preferred that The acid value of the resin obtained by reacting the dibasic acid anhydride can be easily adjusted by selecting the amount of the dibasic acid anhydride to be reacted. Acid value of resin obtained by reacting dibasic acid anhydride is 60mg
If it is less than KOH / g, the diluted alkali developability of the solder photoresist ink composition may be reduced. The acid value of the resin obtained by reacting the dibasic acid anhydride is 140
If it exceeds mgKOH / g, the storage stability of the solder photoresist ink composition may decrease.

The solder photoresist ink composition of the present invention is prepared by adding a photopolymerization initiator to the photocurable resin (A) of the present invention.
(B), a diluent (C) and a thermosetting resin (D) are blended as essential components. In the solder photoresist ink composition of the present invention, the photopolymerization initiator of the component (B) is not particularly limited as long as it is a compound that is decomposed by light irradiation to generate a radical and initiates polymerization, for example, benzoin, Benzoins such as benzoin methyl ether, benzophenone, methylbenzophenone, 4,4'-
Benzophenones such as dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxy Acetophenones such as cyclohexyl phenyl ketone, N, N-dimethylaminoacetophenone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-methylanthraquinone,
-Ethylanthraquinone, 1-chloroanthraquinone,
Anthraquinones such as 2-amylanthraquinone and 2-aminoanthraquinone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone,
Thioxanthones such as 4-diisopropylthioxanthone and ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal can be mentioned. One of these photopolymerization initiators can be used alone, or two or more can be used in combination. In the present invention, the compounding amount of the photopolymerization initiator,
The content is preferably 0.2 to 20 parts by weight, more preferably 1 to 10 parts by weight, per 100 parts by weight of the photocurable resin in the solder photoresist ink composition. If the amount of the photopolymerization initiator is less than 0.2 parts by weight per 100 parts by weight of the photocurable resin, the solder photoresist ink composition may not be sufficiently cured by light irradiation. If the amount of the photopolymerization initiator exceeds 20 parts by weight per 100 parts by weight of the photocurable resin, the heat resistance of the cured coating film may be reduced. In the present invention, in addition to the photopolymerization initiator, a photopolymerization accelerator such as benzoic acids and tertiary amines can be used in combination.

In the present invention, a photopolymerizable monomer or an organic solvent can be used as the diluent for the component (C). As the photopolymerizable monomer that can be used as a diluent, for example, methyl (meth) acrylate, ethyl
(Meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate,
Stearyl (meth) acrylate, cyclohexyl (meth)
Acrylate, phenoxyethyl (meth) acrylate,
2-ethoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, benzyl (meth) acrylate, ethylene glycol mono (meth) acrylate, Ethyl carbitol
Monofunctional acrylate compounds such as (meth) acrylate,
Ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri
(Meth) acrylate, pentaerythritol tri (meth)
Examples thereof include polyfunctional acrylates such as acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and polyfunctional epoxy acrylates. Examples of the organic solvent that can be used as a diluent include, for example, methyl ethyl ketone, ketones such as cyclohexanone, aromatic hydrocarbons such as toluene and xylene, methanol, isopropanol, alcohols such as cyclohexanol, cyclohexane, and methylcyclohexane. Petroleum solvents such as alicyclic hydrocarbons, petroleum ether, petroleum naphtha, cellosolves such as cellosolve and butyl cellosolve, carbitols such as carbitol and butyl carbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate and carbitol Examples thereof include acetates such as tall acetate and butyl carbitol acetate. In the present invention, one of these diluents can be used alone, or two or more thereof can be used in combination.

When the diluent is a photopolymerizable monomer, the photopolymerizable monomer has a role of diluting the solder photoresist ink composition and adjusting the viscosity to be easily applied, and also has a role of promoting photopolymerization. Fulfill. When the diluent is an organic solvent, the organic solvent plays a role of diluting the solder photoresist ink composition, adjusting the viscosity to be easily applied, applying the composition to a printed wiring board, and then drying the composition to form a film. In the present invention, when a reaction diluent is used in the reaction of the epoxy resin with the carboxylic acid and the dibasic acid anhydride, and the reaction diluent is present in the solution of the photocurable resin of the component (A), The reaction diluent can be used as it is as the diluent of the component (C). Further, if necessary, a diluent of the component (C) can be newly added in addition to the reaction diluent present in the solution of the photocurable resin. In the solder photoresist ink composition of the present invention, the compounding amount of the diluent of the component (C) is preferably 30 to 200 parts by weight per 100 parts by weight of the photocurable resin of the component (A). If the amount of the diluent is less than 30 parts by weight per 100 parts by weight of the photocurable resin, the viscosity of the solder photoresist ink composition may be high, and uniform application may be difficult. If the amount of the diluent exceeds 200 parts by weight per 100 parts by weight of the photocurable resin, the viscosity of the solder photoresist ink composition is low, and it may be difficult to obtain a required coating film thickness.

In the solder photoresist ink composition of the present invention, the thermosetting resin as the component (D) is not particularly limited, and examples thereof include an epoxy resin, a polyester resin, and a urethane resin. By blending the thermosetting resin of component (D), the coating applied on the substrate and cured by light irradiation is further thermally cured by heating to obtain adhesion, heat resistance, electrical insulation, moisture resistance, etc. Can improve the coating film performance. The thermosetting resin of the component (D) is preferably a resin that can react with a carboxyl group remaining in the photocurable resin and can be blocked,
More preferably a bifunctional or higher epoxy resin,
More preferably, it is a 2- to 9-functional epoxy resin. In the present invention, the content of the thermosetting resin of the component (D) is 5 to 6 per 100 parts by weight of the photocurable resin of the component (A).
It is preferably 0 parts by weight, more preferably 10 to 40 parts by weight. If the content of the thermosetting resin is less than 5 parts by weight per 100 parts by weight of the photocurable resin, the adhesion and heat resistance of the cured coating film may be reduced. The content of the thermosetting resin is 60 per 100 parts by weight of the photocurable resin.
If the amount is more than 10 parts by weight, dilute alkali developability may be reduced. In the present invention, in order to accelerate the thermosetting reaction of the thermosetting resin of the component (D), imidazoles, amine compounds, triazine compounds, adducts of triazine compounds and isocyanuric acid, carboxylic acids, phenols,
Curing accelerators such as quaternary ammonium salts and compounds containing a methylol group can be used in combination. (D) The thermosetting resin of the component is used immediately before being applied to a printed wiring board in order to avoid the viscosity increase of the solder photoresist ink composition and, consequently, the decrease in dilute alkali developability. It is preferable to use a mixture with essential components.

In the present invention, if necessary, fillers such as barium sulfate and silicon oxide, coloring pigments such as phthalocyanine green, phthalocyanine blue, titanium dioxide and carbon black, defoaming may be added to the solder photoresist ink composition. And various additives such as a leveling agent, and a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, pyrogallol, and t-butylcatechol. The solder photoresist ink composition of the present invention is, for example, applied to the entire surface of a printed wiring board by a screen printing method, a roll coater method, a spray method, a curtain coater method or the like, dried at 65 to 80 ° C., and adhered to the surface. After removing the property (tack), unnecessary portions are masked with a photomask or the like, and photo-curing can be performed. After photo-curing, the unexposed portion is dissolved using a dilute alkaline aqueous solution, and further subjected to thermal curing to obtain a cured solder resist film. There is no particular limitation on the irradiation light source for light curing,
Low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp,
A xenon lamp, a metal halide lamp, or the like can be used.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. The shelf life, photocurability, composition developability, and coating film performance were evaluated by the following methods. (1) Shelf life of photocurable resin solution Put the photocurable resin solution in a plastic bottle with a lid, leave it in a thermostat at 60 ° C, measure the viscosity every 5 days, and measure the viscosity at 25 ° C. The number of days to keep less than 1,000 poise was defined as shelf life. (2) Photocurable A 21-step tablet is applied to the copper foil substrate for testing.
Perform UV exposure at an intensity of 100 mJ / cm ² and 300 mJ / cm ^2, using a 1 wt% aqueous solution of sodium carbonate as a developing solution, after developing by 5 minutes with a stirrer stirring at 20 ° C., the maximum coating remained completely The evaluation was based on the number of stages. The greater the number of steps, the better the photocurability. (3) Dilute alkali developability 200mJ
After curing by UV exposure at an intensity of / cm ² , the developability when developing with a 1% by weight aqueous sodium carbonate solution as a developing solution by stirring at 20 ° C. for 5 minutes was evaluated according to the following criteria. . ◎: Developable within 1 minute ○: Developable within 3 minutes and more than 1 minute △: Developable within 5 minutes and more than 3 minutes ×: Unable to develop within 5 minutes (4) Adhesion JIS K 54008 In accordance with .5.2, cut through the coating on the test printed wiring board and reach the bare ground with a 1 mm gap at 11 mm intervals in a grid pattern.
An adhesive tape was peeled off the grid and the adhesion of the coating film after peeling was visually observed. (5) Pencil hardness In accordance with JIS K 5400 8.4.2, the coating film on the test printed wiring board is scratched five times using a pencil [Mitsubishi Pencil Co., Ltd., Mitsubishi Uni], and the density symbols are mutually different. For two adjacent pencils, a set of two or less scratches and less than two scratches was determined, and the pencil concentration symbol of less than two scratches was defined as the pencil hardness of the coating film. (6) Solder heat resistance A rosin-based flux [Asahi Chemical Laboratory Co., Ltd., GX-7] is applied to the printed wiring board for testing, and 260
The film was floated on a solder bath kept at 15 ° C. for 15 seconds so that the surface of the coating was in contact with the solder, and then the blistering and peeling of the coating were observed. This was defined as one cycle, and the evaluation was made based on the total time up to the cycle before the cycle in which blistering and peeling of the coating film occurred. (7) Flux resistance for leveler A flux for leveler [MEC, FLAXW-139] is applied to a test printed wiring board, and 260 ° C.
Immersed in a solder bath for 15 seconds and taken out.
After immersion in warm water for 15 minutes, a peeling test was conducted with an adhesive tape. At the same time, the whitening state and gloss of the coating film surface were observed and evaluated according to the following criteria. Peeling test ◎: Peeling off at all ○: Peeling less than 10% of the whole △: Peeling off 10 to 30% of the whole ×: Peeling over 30% of the whole Whitening state ◎: Whitening completely Not glossy, surface gloss not lost ○: Not whitened at all, surface gloss lost △: Less than 10% of all whitened ×: Overall Example 1 (photo-curable resin) In a 2-liter separable flask, 460.7 g of diethylene glycol monoethyl ether acetate was added.
-Cresol novolak epoxy resin [Nippon Kayaku
EOCN-103S, epoxy equivalent 215, softening point 83 ° C] 430.0 g, acrylic acid 115.2 g (1.
6 mol), 159.2 g of pentaerythritol triacrylate / succinic anhydride adduct represented by the formula [1] (0.1 mol).
4 mol). Heat to 120 ° C with stirring,
The reaction was continued for 10 hours while maintaining 120 ° C. Once the reaction product has cooled to room temperature, 60.0 g of succinic anhydride
(0.6 mol), 91.2 g of tetrahydrophthalic anhydride
(0.6 mol), and the mixture was heated to 80 ° C. and reacted for 4 hours. When the reaction product was cooled to room temperature, a viscous solution was obtained. The nonvolatile content of this resin solution is 65% by weight
51 mgKOH / g as a solution (7
9 mg KOH / g). The shelf life of this resin solution was 40 days. This resin solution is referred to as “resin solution A”. Example 2 (Photo-curable resin) In a 2-liter separable flask, 369.4 g of propylene glycol monomethyl ether acetate, o
-Cresol novolak epoxy resin [Toto Kasei
Epototh YDCN-703, epoxy equivalent 21
5, softening point 83 ° C] 430.0 g, acrylic acid 142.6
g (1.98 mol) and 13.5 g (0.02 mol) of an adduct of dipentaerythritol pentaacrylate / tetrahydrophthalic anhydride represented by the formula [2] were charged. Heat to 120 ° C with stirring, and maintain at 120 ° C for 10 minutes.
The reaction was continued for hours. Once the reaction product was cooled to room temperature, 100 g (1.0 mol) of succinic anhydride was added and 80
The mixture was heated to ℃ and reacted for 4 hours. When the reaction product was cooled to room temperature, a viscous solution was obtained. The non-volatile content of this resin solution was 65% by weight.
An acid value of H / g (82 mgKOH / g as a non-volatile content) was shown. The shelf life of this resin solution was 45 days. This resin solution is referred to as a resin solution B. Example 3 (Photocurable resin) In a 2-liter separable flask, 495.2 g of diethylene glycol monoethyl ether acetate was added.
-Cresol novolac epoxy resin [Sumitomo Chemical
Sumi-Epoxy ESCN-220F, Epoxy equivalent 215, Softening point 80 ° C] 430.0 g, Acrylic acid 1
15.2 g (1.6 mol) of isocyanuric acid ethylene oxide 3 mol adduct diacrylate of the formula [3].
187.6 g (0.4 mol) of the succinic anhydride adduct were charged. The mixture was heated to 120 ° C. with stirring, and the reaction was continued for 10 hours while maintaining the temperature at 120 ° C. Once the reaction product was cooled to room temperature, 50.0 g (0.5 mol) of succinic anhydride and 136.8 g (0.9 mol) of tetrahydrophthalic anhydride were added, and the mixture was heated to 80 ° C. and reacted for 4 hours. When the reaction product was cooled to room temperature, a viscous solution was obtained. The nonvolatile content of this resin solution was 65% by weight, and the acid value of the solution was 56 mgKOH / g (85 mgKOH / g as the nonvolatile content). The shelf life of this resin solution was 50 days. This resin solution is referred to as a resin solution C. Example 4 (Photo-curable resin) In a 2-liter separable flask, 477.3 g of petroleum naphtha [Shell Chemical AB, Shell Sol AB], o-
Cresol novolak epoxy resin [Sumitomo Chemical Co., Ltd.
Sumi-epoxy ESCN-220HH, epoxy equivalent 2
15, softening point 90 ° C.] 430.0 g, acrylic acid 115.
2 g (1.6 mol) and 180.0 g (0.4 mol) of an adduct of pentaerythritol triacrylate / tetrahydrophthalic anhydride represented by the formula [4] were charged. The mixture was heated to 120 ° C. with stirring, and the reaction was continued for 10 hours while maintaining the temperature at 120 ° C. Once the reaction product has cooled to room temperature,
70.0 g (0.7 mol) of succinic anhydride and 91.2 g (0.6 mol) of tetrahydrophthalic anhydride were added, and the mixture was heated to 80 ° C. and reacted for 4 hours. When the reaction product was cooled to room temperature, a viscous solution was obtained. The nonvolatile content of this resin solution was 65% by weight, and the solution was 53 mgKOH / g.
(82 mg KOH / g as a non-volatile content). The shelf life of this resin solution was 40 days. This resin solution is referred to as a resin solution D. Comparative Example 1 (photo-curable resin) In a 2-liter separable flask, 379.7 g of diethylene glycol monoethyl ether acetate was added.
-Cresol novolak epoxy resin [Nippon Kayaku
Co., Ltd., EOCN-103S, epoxy equivalent 215, softening point 83 ° C.] 430.0 g, and acrylic acid 144.0 g (2 mol) were charged. Heat to 120 ° C with stirring, 12
The reaction was continued for 10 hours while maintaining 0 ° C. Once the reaction product was cooled to room temperature, 40.0 g of succinic anhydride (0.
4 mol), 91.2 g (0.6) of tetrahydrophthalic anhydride
Mol), and the mixture was heated to 80 ° C and reacted for 4 hours. When the reaction product was cooled to room temperature, a viscous solution was obtained. The nonvolatile content of this resin solution is 65% by weight,
52 mg KOH / g as a solution (80 mg KOH /
g). The shelf life of this resin solution was 45 days. This resin solution is referred to as a resin solution E. Table 1 shows the charged compositions of Examples 1 to 4 and Comparative Example 1, and the acid value and shelf life of the obtained photocurable resin solution.

[0018]

[Table 1]

The photocurable resin solutions A, B, C and D of the present invention obtained in Examples 1 to 4 have almost the same shelf life as the photocurable resin solution E obtained in Comparative Example 1. It can be seen that it has storage stability equivalent to that of a conventional photocurable resin. Example 5 (Solder photoresist ink composition) 55 g of resin solution A, 5 g of dipentaerythritol tetraacrylate, 3 g of photopolymerization initiator [Ciba Geigy Co., Irgacure 907], photosensitizer [Nippon Kayaku Co., Ltd., Kayacure] DETX-S] 1 g, barium sulfate 12 g, silicon oxide 10 g, curing accelerator [Shikoku Chemical Industry Co., Ltd., Curesol 2MA-OK] 0.5 g, phthalocyanine green pigment 3 g and defoamer [Nichika Chemical Co., Ltd. Foam Rex SOL-30] 0.5g roll mill (three rolls)
Was used to prepare a solder photoresist ink composition (1 liquid). Subsequently, o-
Cresol novolak type epoxy resin [Toto Kasei Co., Ltd.
Epotote YDCN-702S] in 65% by weight of diethylene glycol monoethyl ether acetate solution (2
8g) to obtain a solder photoresist ink composition. This solder photoresist ink composition is applied to a copper printed wiring board, which has been patterned in advance by etching, to a thickness of 1 by screen printing.
The composition was applied to the entire surface so as to obtain a cured film having a thickness of 5 to 20 μm, and was temporarily dried at 80 ° C. for 30 minutes using a hot air circulation type drying furnace. The temporary dry test substrate, by applying a 21-step tablet photocurable evaluation performs ultraviolet irradiation 100 mJ / cm ² and 300 mJ / cm ² by 3kW metal halide lamp, and alkali developing, evaluating the photocurable did. 100
On the test substrate irradiated with mJ / cm ^{2, the} coating film completely remains up to Step 6, and on the test substrate irradiated with 300 mJ / cm ^2, Step 1
The coating film completely remained up to 1. Further, a photomask was applied to another temporarily dried test substrate, and irradiated with ultraviolet rays at 200 mJ / cm ² to perform photocuring. Then, using a 1% by weight aqueous solution of sodium carbonate as a developing solution, the uncured portion of the coating film was removed, and the dilute alkali developability was evaluated. The developed test substrate is finally 150
Thermal curing was performed at 30 ° C. for 30 minutes to complete a test printed wiring board. The adhesion of the coating film was 10 points, and the pencil hardness of the coating film was 7H. In the solder heat resistance test, there was no abnormality up to the sixth cycle, and slight swelling occurred at the seventh cycle. In the flux resistance test for leveler, no whitening occurred, there was no abnormality in the gloss of the surface, and no peeling occurred in the peeling test. Example 6 (Solder photoresist ink composition) A solder photoresist ink composition was prepared and evaluated in the same manner as in Example 5 except that the resin solution B was used instead of the resin solution A. In the evaluation of photocurability, 10
0 mJ / cm ² irradiated test substrate remains in completely coating to Step 4, the test substrate was irradiated 300 mJ / cm ² coating film remained completely until step 8. In the evaluation of dilute alkali developability, development was possible within one minute. The adhesion of the coating film was 10 points, and the pencil hardness of the coating film was 5H. In the solder heat resistance test, there was no abnormality up to 3 cycles, and 4
Slight flaking occurred at the cycle. In the flux test for leveler resistance, about 5% of the total in the peeling test
Peeling occurred. Also, although no whitening occurred,
The surface gloss was lost. Example 7 (Solder photoresist ink composition) A solder photoresist ink composition was prepared and evaluated in the same manner as in Example 5 except that the resin solution C was used instead of the resin solution A. In the evaluation of photocurability, 10
0 mJ / cm ² irradiated test substrate remains in completely coating to Step 4, the test substrate was irradiated 300 mJ / cm ² coating film remained completely until step 9. In evaluation of dilute alkali developability, development was possible in 1 minute and 10 seconds. The adhesion of the coating film was 10 points, and the pencil hardness of the coating film was 6H. In the solder heat resistance test, there was no abnormality up to 3 cycles, and 4
Slight flaking occurred at the cycle. In the flux test for leveler resistance, about 5% of the total in the peeling test
Peeling occurred. No whitening occurred, and there was no abnormality in the surface gloss. Example 8 (Solder photoresist ink composition) A solder photoresist ink composition was prepared and evaluated in the same manner as in Example 5 except that the resin solution D was used instead of the resin solution A. In the evaluation of photocurability, 10
0 mJ / cm ² irradiated test substrate remains in completely coating to Step 5, the test substrate was irradiated 300 mJ / cm ² coating film remained completely until step 10. In the evaluation of dilute alkali developability, development was possible within one minute. The adhesion of the coating film was 10 points, and the pencil hardness of the coating film was 6H. In the solder heat resistance test, there was no abnormality up to 5 cycles, and 6
Slight flaking occurred at the cycle. In the flux resistance test for leveler, no peeling occurred in the peeling test. No whitening occurred, and there was no abnormality in the surface gloss. Comparative Example 2 (Solder Photoresist Ink Composition) A solder photoresist ink composition was prepared and evaluated in the same manner as in Example 5 except that the resin solution E was used instead of the resin solution A. In the evaluation of photocurability, 10
0 mJ / cm ² irradiated test substrate remains in completely coating to Step 2, the test substrate was irradiated 300 mJ / cm ² coating film remained completely until Step 6. In the evaluation of dilute alkali developability, development was possible within one minute. The adhesion of the coating film was 10 points, and the pencil hardness of the coating film was 5H. In the solder heat resistance test, there was no abnormality up to three cycles, and slight peeling occurred in the fourth cycle. In the leveler flux resistance test, about 5% of the whole peeled off in the peeling test. Further, no whitening occurred, but the gloss of the surface was lost. Table 2 shows the results of Examples 5 to 8 and Comparative Example 2.

[0020]

[Table 2]

The solder photoresist ink compositions of the present invention of Examples 5 to 8 have remarkably excellent photocurability as compared with the conventional solder photoresist ink compositions represented by Comparative Example 2. In particular, the photocurability at a low exposure dose of 100 mJ / cm ² is good. Further, the solder photoresist ink composition of the present invention shows good alkali developability. The solder photoresist ink composition of the present invention has excellent resist performance, good adhesion of a cured coating film, and high pencil hardness. As for the solder heat resistance and the flux resistance for leveler, the same or better performance is shown as compared with the conventional solder photoresist ink composition.

[0022]

The photocurable resin of the present invention and the solder photoresist ink composition using the same are excellent in curability at a small amount of ultraviolet light exposure, and the photosensitivity is that of the conventional solder photoresist ink composition. Significantly higher. Further, the cured film is excellent in heat resistance and flux resistance for leveler, and its performance exceeds that of the conventional solder photoresist ink composition. It has excellent resist properties such as adhesion and hardness, and has the same or better performance than conventional solder photoresist ink compositions.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03F 7/038 503 G03F 7/038 503

Claims (2)

[Claims] 1. An epoxy resin obtained by reacting 0.5 to 50 mol% of a monocarboxylic acid having two or more acryloyl groups in one molecule with 50 to 99.5 mol% of acrylic acid or methacrylic acid. A photocurable resin having a radically polymerizable unsaturated acyl group and a carboxyl group obtained by further reacting a compound obtained with a dibasic acid anhydride. 2. The photocurable resin (A) according to claim 1, wherein a photopolymerization initiator (B), a diluent (C), and a thermosetting resin (D) are blended. Solder photoresist ink composition.