JP2963069B2 - Solder photoresist ink composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a solder photoresist ink composition. More specifically, the present invention relates to a solder photoresist ink composition which is in a liquid form, has excellent ultraviolet curability, and can be subjected to photographic development with a dilute alkaline aqueous solution when manufacturing a printed wiring board.

[0002]

2. Description of the Related Art At present, solder resist inks for various printed wiring boards have been shifted from thermosetting liquid resist resins and dry film resist resins by screen printing to dilute alkali developing liquid solder photoresist inks. I have. For example, Japanese Patent Publication No. 1-54390
In the publication, a reaction product of a novolak type epoxy compound and an unsaturated monocarboxylic acid, an active energy ray-curable resin obtained by reacting a saturated or unsaturated polybasic acid anhydride,
A liquid resist ink composition comprising a photopolymerization initiator, a diluent, and a thermosetting component comprising an epoxy compound having two or more epoxy groups in one molecule is disclosed.
However, a photoresist ink based on an active energy ray-curable resin obtained by reacting a reaction product of the novolak type epoxy compound with an unsaturated monocarboxylic acid and a saturated or unsaturated polybasic acid anhydride has a light-emitting property. There is a disadvantage that the curability is low. Recently, in the processing of solder photoresist ink, the speed of the production line has been increased in order to shorten the production time, and as a result, the exposure time by ultraviolet rays tends to decrease. When the exposure amount is below the appropriate value, the curing of the resist ink becomes insufficient, and there is a possibility of causing a fatal defect that the cured film is peeled off in the next step of alkali development.
On the other hand, Japanese Unexamined Patent Publication No.
With the above novolak type epoxy resin, reacting (meth) acrylic acid to introduce a (meth) acryloyl group,
Photopolymerizable resin, photopolymerization initiator and dilution obtained by increasing the molecular weight using a chain extender having two or more functional groups capable of reacting with an epoxy group or a hydroxyl group via a hydroxyl group generated by this reaction An ink composition for solder resist containing an agent is disclosed. JP-A-6-258830 discloses an ester of (meth) acrylic acid and an ethylene glycol monomer or oligomer or glycerol (meth) acrylate, glycidyl.
UV-curable resin obtained by reacting (meth) acrylate and a copolymer with other ethylenically unsaturated monomers with (meth) acrylic acid and a saturated or unsaturated polybasic anhydride, photopolymerization initiation A resist ink composition comprising an agent, a diluent and a thermosetting epoxy compound is disclosed. In addition, JP-A-6-301206 discloses a resist ink composition for etching comprising a carboxyl group-containing polymer having a weight average molecular weight of 20,000 to 300,000. However, all of these compositions promote the crosslinking of the resin by significantly increasing the molecular weight of the photocurable resin, and the use of a resin having a high molecular weight increases the viscosity of the photoresist ink. Therefore, the workability at the time of handling is deteriorated, and the storage stability of the photoresist ink tends to be deteriorated.

[0003]

DISCLOSURE OF THE INVENTION The present invention significantly improves the photocurability of a dilute alkali-developable solder photoresist ink composition containing a conventional ultraviolet curable resin, and provides an ultraviolet curable resin and a photopolymerization initiator. As a composition containing a diluent and a thermosetting resin, it can be cured at a low exposure dose, has good storage stability, diluted alkali developability, adhesion of a cured coating film to a substrate, heat resistance, The object of the present invention is to provide a solder photoresist ink composition having excellent surface hardness.

[0004]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, as a UV-curable resin, a carboxyl group of a resin having a radical polymerizable unsaturated acyl group and a carboxyl group. By using a resin obtained by reacting a compound having one epoxy group and one or more radically polymerizable unsaturated groups in one molecule, the photocurability of the solder photoresist ink composition is remarkable. With low viscosity, good storage stability, excellent dilute alkali developability, the cured coating has excellent adhesion, heat resistance, surface hardness, and water-soluble flux. The present invention has been completed based on the findings. That is, the present invention provides: (1) 100 parts by weight of an ultraviolet curable resin (A), 0.2 to 20 parts by weight of a photopolymerization initiator (B), and 30 to 2 parts of a diluent (C).
In a solder photoresist ink composition containing 00 parts by weight and 5 to 60 parts by weight of the thermosetting resin (D),
The ultraviolet-curable resin is a resin having an acid value of 80 to 170 mgKOH / g having a radically polymerizable unsaturated acyl group and a carboxyl group. One epoxy group and one or more radically polymerizable unsaturated groups are added to the carboxyl group of the resin. The compound (E) having the compound (E) in the resin having the radically polymerizable unsaturated acyl group and the carboxyl group per 1 equivalent of the carboxyl group,
0.05 to 0.4 mol, which is 100 mj /
It has four or more steps of photocurability in a photocurability test by UV exposure of cm ² intensity, and has a dilute alkali developability that can be developed within 1 minute in a development test with a 1% by weight aqueous solution of sodium carbonate at 20 ° C. (2) a resin having a radical polymerizable unsaturated acyl group and a carboxyl group, wherein a reaction product of an epoxy resin and an unsaturated monocarboxylic acid is used as a dibasic acid anhydride; Wherein the epoxy resin is an o-cresol novolak type epoxy having a softening point of 75 ° C. or more, which is a resin having an acid value of 80 to 170 mg KOH / g obtained by reacting Resin, a phenol novolak epoxy resin having a softening point of 60 ° C. or higher and a bisphenol A novolak epoxy resin having a softening point of 60 ° C. or higher (2) The amount of a dibasic acid anhydride to be reacted with a reaction product of an epoxy resin and an unsaturated monocarboxylic acid, wherein the solder photoresist ink composition according to (2) is at least one selected resin. Wherein the amount of the unsaturated monocarboxylic acid reacted with the epoxy resin is 0.4 to 1.0 times by mole, (5) a radically polymerizable unsaturated acyl group, The solder photoresist ink composition according to item (1), wherein the reaction between the carboxyl group of the resin having a carboxyl group and the compound (E) is performed at a temperature of 80 to 120 ° C., and (6) heat of the component (D). (2) The solder photoresist ink composition according to the above (1), wherein the curable resin is a bifunctional or higher epoxy resin. Further, as a preferred embodiment of the present invention, (7) the epoxy resin and the unsaturated monocarboxylic acid having a reaction molar ratio of 0.9 to 1.1 moles of unsaturated monocarboxylic acid per 1.0 equivalent of epoxy group. (8) a solder photoresist ink composition according to item (2), and (8) a resin having a radically polymerizable unsaturated acyl group and a carboxyl group, one epoxy group and one or more radically polymerizable unsaturated groups. The solder photoresist ink composition according to item (1), wherein the reaction of the compound to be incorporated into the molecule is performed at 100 to 120 ° C.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The solder photoresist ink composition of the present invention comprises an ultraviolet curable resin (A), a photopolymerization initiator.
(B), containing a diluent (C) and a thermosetting resin (D);
A compound in which the ultraviolet-curable resin of the component has one epoxy group and one or more radically polymerizable unsaturated groups in one molecule in a carboxyl group of a resin having a radically polymerizable unsaturated acyl group and a carboxyl group ( Obtained by reacting E). In the present invention, the resin having a radically polymerizable unsaturated acyl group and a carboxyl group as a raw material of the ultraviolet curable resin is not particularly limited, but a reaction product of an epoxy resin and an unsaturated monocarboxylic acid is used.
A resin obtained by reacting a dibasic acid anhydride can be suitably used. There is no particular limitation on the epoxy resin to be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, phenol novolak type epoxy resin,
Cresol novolak epoxy resin, bisphenol A novolak epoxy resin, cycloaliphatic epoxy resin, glycidyl ester resin, glycidylamine resin, heterocyclic ester resin, and the like can be given.
Among these, phenol novolak type epoxy resin,
Cresol novolak type epoxy resins and bisphenol A novolak type epoxy resins can be particularly preferably used. The epoxy resin used has a softening point of 60 ° C.
It is preferable that it is above. By reacting the epoxy resin with the unsaturated monocarboxylic acid, the oxirane ring is cleaved by the reaction between the epoxy group and the carboxyl group to form a hydroxyl group and an ester bond. The unsaturated monocarboxylic acid that reacts with the epoxy resin is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, crotonic acid, vinyl acetic acid, sorbic acid, and cinnamic acid. Among them, acrylic acid can be used particularly preferably because it has good reactivity with epoxy groups and the resulting resin has excellent ultraviolet curability. In the present invention, one kind of the unsaturated monocarboxylic acid can be used alone, or two or more kinds can be used in combination. The reaction between the epoxy resin and the unsaturated monocarboxylic acid can be carried out by heating in a suitable reaction diluent.

In the present invention, a photopolymerizable monomer or an organic solvent can be used as a reaction diluent for the reaction between the epoxy resin and the unsaturated monocarboxylic acid. 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-ethoxyethyl (meth) acrylate, 2-butoxyethyl
(Meth) acrylate, glycidyl (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 which 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;
Alicyclic hydrocarbons such as methylcyclohexane, petroleum solvents such as petroleum ether, petroleum naphtha, cellosolve,
Cellosolves such as butyl cellosolve, carbitol,
Examples thereof include carbitols such as butyl carbitol, and acetates such as ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, and butyl carbitol acetate. In the present invention, one type of reaction diluent can be used alone, or two or more types can be used in combination. The reaction diluent is preferably added so as to be 20 to 50% by weight based on the total weight of the reaction system. In the present invention, the amount of the epoxy group of the epoxy resin, the amount of the unsaturated monocarboxylic acid to be reacted,
It is preferably approximately equivalent. If the epoxy group is in excess, an undesired reaction may be caused during the subsequent synthesis reaction, resulting in gelation of the resin or a decrease in the storage stability of the solder photoresist ink composition. If the amount of the unsaturated monocarboxylic acid is excessive, unreacted carboxyl groups remain and a low-molecular-weight compound is contained in the resin, which may deteriorate the properties of the cured coating film. In the present invention, the reaction temperature between the epoxy resin and the unsaturated monocarboxylic acid is preferably 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. If the reaction temperature exceeds 120 ° C., the unsaturated monocarboxylic acid undergoes thermal polymerization, which may cause gelation during the reaction.

In the present invention, a dibasic acid anhydride is further reacted with the reaction product of the epoxy resin and the unsaturated monocarboxylic acid. The reaction product of the epoxy resin and the unsaturated monocarboxylic 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. Examples of dibasic acid anhydrides include, for example, succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride,
Methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendmethylenetetrahydrophthalic anhydride,
Methylbutenyltetrahydrophthalic anhydride, chlorendic anhydride and the like can be mentioned. 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 may be used alone, or two or more types may be used in combination. The dibasic acid anhydride reacts with the hydroxyl group of the reaction product of the epoxy resin and the unsaturated monocarboxylic acid to form an ester bond and a free carboxyl group. The amount of the dibasic acid anhydride to be reacted is preferably 0.4 to 1.0 times the amount of the unsaturated monocarboxylic acid reacted with the epoxy resin. In the epoxy resin, an equivalent number of hydroxyl groups equal to the number of moles of the reacted unsaturated monocarboxylic acid is generated, and in addition, the hydroxyl groups originally contained in the epoxy resin are present. By reacting the dibasic acid anhydride in an amount of from 0.4 mol to 1.0 mol times of the unsaturated monocarboxylic acid reacted with the epoxy resin, a part of the hydroxyl groups of the resin is left as it is, and the remaining hydroxyl groups are esterified. Can be When the amount of the dibasic acid anhydride to be reacted is less than 0.4 mole times the unsaturated monocarboxylic acid reacted with the epoxy resin, the diluted 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 mole times the unsaturated monocarboxylic acid reacted with the epoxy resin, the storage stability of the solder photoresist ink composition may be deteriorated.

In the present invention, a dibasic acid anhydride is added to a reaction product of an epoxy resin and an unsaturated monocarboxylic 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 70C to 100C. The resin obtained by reacting a reaction product of an epoxy resin and an unsaturated monocarboxylic acid with a dibasic acid anhydride preferably has an acid value of 80 to 170 mgKOH / g,
More preferably, it is 160 mgKOH / g. 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. If the acid value of the resin obtained by reacting the dibasic acid anhydride is less than 80 mgKOH / g, the diluted alkali developability of the solder photoresist ink composition may be reduced. If the acid value of the resin obtained by reacting the dibasic acid anhydride exceeds 170 mgKOH / g, the storage stability of the solder photoresist ink composition may be deteriorated. In the present invention, a reaction product of an epoxy resin and an unsaturated monocarboxylic acid, obtained by reacting a dibasic acid anhydride, to a carboxyl group of a resin having a radical polymerizable unsaturated acyl group and a carboxyl group, A compound (E) having one epoxy group and one or more radically polymerizable unsaturated groups in one molecule is reacted. When the carboxyl group and the epoxy group react to form an ester bond, the radically polymerizable unsaturated group is bonded to the main chain of the resin.
Since the radically polymerizable unsaturated group bonded by this reaction is bonded to the outermost part of the ultraviolet curable resin, the reactivity at the time of photopolymerization of the resin by ultraviolet light is stereochemically high. Therefore, this ultraviolet curable resin has good photocurability.

In the present invention, the reaction ratio of a resin having a radical polymerizable unsaturated acyl group and a carboxyl group to a compound having one epoxy group and one or more radical polymerizable unsaturated groups in one molecule is as follows: A compound having one epoxy group and one or more radically polymerizable unsaturated groups in one molecule per one equivalent of a carboxyl group of a resin having a radically polymerizable unsaturated acyl group and a carboxyl group.
Preferably it is ~ 0.4 mol. The amount of a compound having one epoxy group and one or more radically polymerizable unsaturated groups in one molecule is 0.1 per carboxyl group equivalent.
If the amount is less than 05 mol, the photocurability of the ultraviolet curable resin may decrease. When the amount of the compound having one epoxy group and one or more radically polymerizable unsaturated groups in one molecule exceeds 0.4 mol per equivalent of the carboxyl group, the diluted alkali developing of the solder photoresist ink composition is performed. And the chemical resistance of the cured coating film may decrease. As a compound having one epoxy group and one or more radically polymerizable unsaturated groups in one molecule, for example,
Glycidyl acrylate, glycidyl methacrylate,
Examples thereof include pentaerythritol glycidyl ether triacrylate and the compound represented by the general formula [1].

Embedded image In the general formula [1], n is 0, 1 or 2, R is hydrogen or a methyl group, A is a 6-oxabicyclo [3.1.0] hexyl group, 7-oxabicyclo [4.1] .
0] heptyl group or 8-oxabicyclo [5.1.0] octyl group. In the present invention, a compound having one epoxy group and one or more radically polymerizable unsaturated groups in one molecule is reacted with a carboxyl group of a resin having a radically polymerizable unsaturated acyl group and a carboxyl group. The obtained ultraviolet curable resin is used. When a resin having a radically polymerizable unsaturated acyl group and a carboxyl group is present as a solution of a reaction diluent, one epoxy group and one or more radically polymerizable unsaturated groups are combined into one molecule in this solution. By adding and dissolving the compound having the compound, the reaction can be favorably advanced. During the reaction, a reaction diluent can be further added for effective stirring. The reaction temperature is preferably from 80 to 120 ° C. In the present invention, the ultraviolet curable resin (A) is
The acid value is preferably from 60 to 110 mgKOH / g.
If the acid value of the ultraviolet curable resin is less than 60 mgKOH / g, the diluted alkali developability of the solder photoresist ink composition may be reduced. If the acid value of the UV-curable resin exceeds 120 mgKOH / g, the chemical resistance of the cured coating film may be reduced.

In the solder photoresist ink composition of the present invention, the photopolymerization initiator of the component (B) is not particularly limited, and any photopolymerization initiator that decomposes upon irradiation with light to generate radicals and initiates polymerization. There is no limitation, 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, thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone and 2-isopropylthioxanthone, and acetophenone Examples thereof include ketals such as dimethyl ketal and benzyl dimethyl ketal. One of these photopolymerization initiators can be used alone, or two or more can be used in combination. The photopolymerization initiator is contained in the solder photoresist ink composition in an amount of 0.2 per 100 parts by weight of the ultraviolet curable resin.
The amount is preferably 20 to 20 parts by weight, more preferably 1 to 10 parts by weight. 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, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-
Monofunctional acrylate compounds such as hydroxypropyl (meth) acrylate, benzyl (meth) acrylate, ethylene glycol mono (meth) acrylate, 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,
Examples include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and polyfunctional acrylates such as 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. Alicyclic hydrocarbons, 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 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 a role of promoting photopolymerization. Also fulfills. 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, a reaction diluent is used in the reaction of the epoxy resin with the unsaturated monocarboxylic acid and the dibasic acid anhydride, and the reaction diluent is present in the solution of the ultraviolet curable resin of the component (A). In this case, 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 ultraviolet curable resin. In the solder photoresist ink composition of the present invention, the content of the diluent (C) is preferably 30 to 200 parts by weight per 100 parts by weight of the ultraviolet curable resin (A). In the solder photoresist ink composition of the present invention, (D)
The thermosetting resin as a component 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 the irradiation of ultraviolet rays is further heated and cured by heating, and the adhesion, heat resistance,
The coating film performance such as electrical insulation and moisture resistance can be improved. The thermosetting resin as the component (D) is preferably a resin capable of reacting with a carboxyl group remaining in the ultraviolet curable resin and blocking the same, more preferably a bifunctional or higher functional epoxy resin. It is more preferable that the epoxy resin is a -9-functional epoxy resin. In the present invention, (D)
The content of the thermosetting resin as the component is preferably 5 to 60 parts by weight, more preferably 10 to 40 parts by weight, per 100 parts by weight of the ultraviolet curable resin as the component (A). When the content of the thermosetting resin is less than 5 parts by weight per 100 parts by weight of the ultraviolet curable resin, the adhesion and heat resistance of the cured coating film may be reduced. If the content of the thermosetting resin exceeds 60 parts by weight per 100 parts by weight of the ultraviolet curable resin, the 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, carboxylic acids, phenols, quaternary ammonium salts,
A curing accelerator such as a methyl roll group-containing compound can be used in combination. The thermosetting resin of the component (D) is used to improve the viscosity of the solder photoresist ink composition and, consequently, reduce the dilute alkali developability, immediately before application to a printed wiring board. It is preferable to mix and use the 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 composition for a solder resist ink of the present invention is, for example, a screen printing method on a printed wiring board, a roll coater method, a spray method,
Apply to the whole surface by curtain coater method, etc.
After drying at 0 ° C to remove the tackiness (tack) on the surface, mask unnecessary parts with a photomask, etc.
Perform light curing. After photo-curing, the unexposed portion is dissolved using a dilute alkaline aqueous solution, and further heat-cured to obtain a cured solder resist coating film. The irradiation light source for photocuring is not particularly limited, and a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, and the like can be used.

[0015]

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 developability and coating film performance of the composition were evaluated by the following methods. (1) Shelf life of UV-curable resin solution The UV-curable resin solution is placed in a plastic bottle with a lid, left in a 60 ° C constant temperature bath, and the viscosity is measured every 5 days. The number of days to keep less than 1,000 pois 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 In the process of producing a test printed wiring board, after being cured by light irradiation, the developability when developing with a 1% by weight aqueous sodium carbonate solution as a developing solution by stirring with a stirrer at 20 ° C. for 5 minutes was examined. The evaluation was performed 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 the coating film swelled and peeled off. (7) Water-soluble flux resistance Water-soluble flux [LO
NCO Co., Ltd., CF-350], floated in a solder bath at 260 ° C for 5 seconds with the coating surface in contact with the solder, immersed in warm water at 60 ° C for 15 minutes, and then performed a peeling test using an adhesive tape. went. At the same time, the whitening state of the coating film surface was observed. The evaluation criteria are shown below. 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 good ：: Less than 10% of all whitened △: 10 to 30% of all whitened ×: More than 30% of all whitened Production Example 1 (UV curing Production of Functional Resin) In a 2-liter separable flask, 411.4 g of ethyl carbitol acetate, o-cresol novolak type epoxy resin [Nippon Kayaku Co., Ltd., EOCN-103]
S, epoxy equivalent 215, softening point 83 ° C] 430 g and acrylic acid 144 g (2 mol) 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, 190 g (1.9 mol) of succinic anhydride was added, and the mixture was heated to 80 ° C. and reacted for 4 hours. Once again, the reaction product was cooled to room temperature. The acid value of this reaction product as a solution was 91 mgKOH / g, and the acid value as a resin was 140 mgKOH / g.
/ G. 85.2 g (0.6 mol) of glycidyl methacrylate and 45.9 g of propylene glycol methyl ether acetate were added to the reaction product, and the mixture was heated to 110 ° C with stirring, and the reaction was continued for 6 hours while maintaining 110 ° C. When the reaction product was cooled to room temperature, a viscous solution was obtained. The heating residue of this solution is 65
%, And the acid value of the solution was 56 mgKOH / g. This solution is referred to as “resin solution A”. Production Example 2 (Production of UV-curable resin) Instead of the o-cresol novolak type epoxy resin of Production Example 1, bisphenol A novolak type epoxy resin [Yukaka Shell Epoxy Co., Ltd., Epicoat 157S70,
Epoxy equivalent 210, softening point 70 ° C] was used. In a 2 liter separable flask, 432.6 g of ethyl carbitol acetate, 420 g of bisphenol A novolak type epoxy resin and 144 g (2 mol) of acrylic acid were used.
Was charged. Heat to 120 ° C with stirring, 120 ° C
The reaction was continued for 10 hours while maintaining the temperature. Once the reaction product was cooled to room temperature, 95 g (0.95 mol) of succinic anhydride and 144.4 g (0.9%) of tetrahydrophthalic anhydride were used.
5 mol), and the mixture was heated to 80 ° C. and reacted for 4 hours. Once again, the reaction product was cooled to room temperature. The acid value of this reaction product as a solution was 86 mgKOH / g, and the acid value as a resin was 133 mgKOH / g. 85.2 g (0.6 mol) of glycidyl methacrylate and 45.9 g of ethyl carbitol acetate were added to the reaction product, and the mixture was heated to 110 ° C. with stirring, and the reaction was continued for 6 hours while maintaining 110 ° C. When the reaction product was cooled to room temperature, a viscous solution was obtained. The heating residue of this solution was 65% by weight, and the solution had an acid value of 53 mgKOH / g. This solution is referred to as a resin solution B. Production Example 3 (Production of UV-curable resin) Instead of glycidyl methacrylate of Production Example 1, glycidyl acrylate was used. In a 2-liter separable flask, 411.4 g of propylene glycol methyl ether acetate and an o-cresol novolak type epoxy resin [Toto Kasei Co., Ltd., Epototh YDCN-70]
3, epoxy equivalent 215, softening point 83 ° C] 430 g and acrylic acid 144 g (2 mol) 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, 190 g (1.9 mol) of succinic anhydride was added, and the mixture was heated to 80 ° C. and reacted for 4 hours. Once again, the reaction product was cooled to room temperature. The acid value of this reaction product as a solution was 91 mgKOH / g, and the acid value as a resin was 140 mgKOH / g.
/ G. 76.8 g (0.6 mol) of glycidyl acrylate and 42 g of butyl cellosolve were added to the reaction product.
Was added and heated to 110 ° C. with stirring, and the reaction was continued for 6 hours while maintaining 110 ° C. When the reaction product was cooled to room temperature, a viscous solution was obtained. The heating residue of this solution was 65% by weight, and 56 mgKOH /
g of acid value. This solution is referred to as a resin solution C. Production Example 4 (Production of UV-curable resin) Instead of glycidyl methacrylate of Production Example 1, 3,4-epoxycyclohexylmethyl acrylate represented by Formula [2] [Daicel Chemical Industries, Ltd., Cyclom
er A200] was used.

Embedded image In a 2-liter separable flask, 438.0 g of ethyl carbitol acetate, o-cresol novolak type epoxy resin [Sumitomo Chemical Co., Ltd., Sumi-Epoxy ESC
N-220F, epoxy equivalent 215, softening point 80 ° C] 4
30 g and 144 g (2 mol) of acrylic acid were charged. Heat to 120 ° C with stirring, and keep the temperature at 120 ° C for 1
The reaction was continued for 0 hours. Once the reaction product was cooled to room temperature, 95 g (0.95 mol) of succinic anhydride and 144.4 g (0.95 mol) of tetrahydrophthalic anhydride were added, and the mixture was heated to 80 ° C. and reacted for 4 hours. Once again, the reaction product was cooled to room temperature. The acid value of this reaction product as a solution was 85 mgKOH / g, and the acid value as a resin was 131 mgKOH / g. 3,4
-Epoxycyclohexylmethyl acrylate 91 g
(0.5 mol) and ethyl carbitol acetate 49
g was added and heated to 110 ° C. with stirring, and the reaction was continued for 6 hours while maintaining 110 ° C. When the reaction product was cooled to room temperature, a viscous solution was obtained. The heating residue of this solution was 65% by weight.
/ G of acid value. This solution is referred to as a resin solution D. Reference Example 1 A synthesis reaction was performed in the same procedure as in Production Example 1, except that the addition reaction of glycidyl methacrylate in Production Example 1 was not performed. In a 2-liter separable flask, 362.9 g of ethyl carbitol acetate, o-cresol novolak type epoxy resin [Sumitomo Chemical Co., Ltd., Sumi-Epoxy E
SCN-220HH, epoxy equivalent 215, softening point 90
° C] and 144 g (2 mol) of acrylic acid. 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, 100 g (1.0 mol) of succinic anhydride was 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 heating residue of this solution was 65% by weight,
It showed an acid value of mgKOH / g. This solution is referred to as a resin solution E. Example 1 55 g of resin solution A, 5 g of dipentaerythritol hexaacrylate, 3 g of a photopolymerization initiator [Ciba Geigy, Irgacure 907], 1 g of a photosensitizer [Nippon Kayaku Co., Ltd., Kayacure DETX-S], 1 g of barium sulfate 12 g, silicon oxide 10 g, curing accelerator [Shikoku Chemical Industry Co., Ltd., Curezol 2MA-OK] 0.5 g, phthalocyanine green pigment 3 g, and antifoaming agent [Nichika Chemical Co., Ltd., Formrex SOL-30] 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.
8 g of a 65% by weight ethyl carbitol acetate solution (2 liquid) of Epotote YDCN-702S] was mixed to obtain a solder photoresist ink composition. This solder photoresist ink composition is applied on the entire surface of a copper printed wiring board which has been etched and patterned in advance by a screen printing method so as to obtain a cured coating film having a thickness of 15 to 20 μm. Preliminary drying was performed at 80 ° C. for 30 minutes using a circulation drying oven. On the temporarily dried test substrate,
Apply a 21-step tablet for photocurability evaluation,
UV light 100mJ / cm ² by 3kW metal halide lamp
And irradiation of 300 mJ / cm ² and alkali development,
The photocurability was evaluated. On the test substrate irradiated with 100 mJ / cm ^{2, the} coating completely remained until step 5, and on the test substrate irradiated with 300 mJ / cm ^{2, the} coating completely remained until step 9.
Also, apply a photomask to another temporarily dried test substrate,
Irradiation with ultraviolet rays of 200 mJ / cm ² was performed to perform photo-curing. Then, using a 1% by weight aqueous solution of sodium carbonate as a developer, the uncured portion of the coating film was removed and the diluted alkali developability was evaluated. As a result, development was possible within one minute. The developed test substrate was finally heat-cured at 150 ° 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 4 cycles, and 5
Slight swelling occurred on the cycle. In the water resistance flux test, whitening occurred in about 3% of the total, but no peeling occurred in the peeling test. The shelf life of the ultraviolet curable resin solution A was 40 days. Example 2 A solder photoresist ink composition was prepared and evaluated in the same manner as in Example 1 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 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 5H.
In the solder heat resistance test, there is no abnormality up to 3 cycles,
Slight delamination occurred in the fourth cycle. In the water-resistant flux test, whitening occurred in about 15% of the total, and in the peeling test, peeling occurred in about 5% of the total. The shelf life of the ultraviolet curable resin solution B was 50 days. Example 3 A solder photoresist ink composition was prepared and evaluated in the same manner as in Example 1 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 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 4 cycles, and 5
Slight swelling occurred on the cycle. In the water resistance flux test, whitening occurred in about 5% of the whole, and in the peeling test, peeling occurred in about 3% of the whole. The shelf life of the ultraviolet curable resin solution C was 45 days. Example 4 A solder photoresist ink composition was prepared and evaluated in the same manner as in Example 1 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 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 8 points, and the pencil hardness of the coating film was 6H. In the solder heat resistance test, there was no abnormality up to the fifth cycle, and slight swelling occurred at the sixth cycle. In the water resistance flux test, whitening occurred in about 3% of the total, and in the peeling test, peeling occurred in about 3% of the total. The shelf life of the ultraviolet curable resin solution D was 50 days. Comparative Example 1 A solder photoresist ink composition was prepared and evaluated in the same manner as in Example 1, 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 3 cycles, and 4
Slight blistering and flaking occurred during the cycle. In the water-resistant flux test, whitening occurred in about 15% of the total, and in the peeling test, peeling occurred in about 5% of the total.
The shelf life of the ultraviolet curable resin solution E was 45 days. Table 1 shows the results of Examples 1 to 4 and Comparative Example 1.

[0016]

[Table 1]

The UV-curable resin solutions A, B, C and D produced in Production Examples 1-4 used in the present invention have almost the same shelf life as the UV-curable resin solution E, It turns out that it has storage stability equivalent to a resin. The solder photoresist ink composition of the present invention has remarkably excellent photocurability as compared with a conventional solder photoresist ink composition represented by a comparative example, particularly at a low exposure amount of 100 mJ / cm ^2. Has good photocurability. In addition, the solder photoresist ink composition of the present invention has good dilute alkali developability.
The solder photoresist ink composition of the present invention has excellent resist performance, good adhesion of a cured coating film, high pencil hardness, and excellent performance in solder heat resistance and water-soluble flux resistance. .

[0018]

EFFECT OF THE INVENTION The solder photoresist ink composition of the present invention has excellent curability at a small amount of UV exposure,
Its light sensitivity is significantly higher than conventional solder photoresist inks. Further, the cured coating film is excellent in adhesion and heat resistance, and has performance equal to or higher than that of a conventional solder photoresist ink composition.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H05K 3/28 H05K 3/28 D // C08F 2/50 C08F 2/50 (56) References JP-A-9-80749 (JP) JP-A-49-16788 (JP, A) JP-A-8-82930 (JP, A) JP-A-7-72624 (JP, A) JP-A-5-19470 (JP, A) 6-258830 (JP, A) JP-A-6-324490 (JP, A) JP-A-7-224143 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03F 7/038 G03F 7/027 G03F 7/028 G03F 7/032 G09D 11/00 C08F 2/50

Claims (6)

(57) [Claims] 1. An ultraviolet curable resin (A) 100 parts by weight , a photopolymerization initiator (B) 0.2 to 20 parts by weight , a diluent (C) 3
0 to 200 parts by weight and thermosetting resin (D) 5 to 60 parts by weight
Part , the ultraviolet curable resin has a radical polymerizable unsaturated acyl group and a carboxyl group having an acid value of 80 to 170 mg KOH.
/ G resin with one epoxy group and one
A compound (E) having two or more radically polymerizable unsaturated groups in one molecule is referred to as the radically polymerizable unsaturated acyl group.
1 equivalent of carboxyl group of resin having carboxyl group
Or obtained by reacting 0.05 to 0.4 mol, and using a 21-step tablet.
In the photo-curing test by UV exposure of 0 mj / cm ² intensity, 4
1% by weight carbonic acid at 20 ° C with more than photo-curing steps
Developable in less than 1 minute in a development test using a sodium aqueous solution
A solder photoresist ink composition having excellent dilute alkali developability . 2. A resin having a radically polymerizable unsaturated acyl group and a carboxyl group is obtained by reacting a reaction product of an epoxy resin with an unsaturated monocarboxylic acid with a dibasic acid anhydride to obtain an acid value of 80 to 80. The solder photoresist ink composition according to claim 1, wherein the resin is 170 mgKOH / g. 3. An epoxy resin having a softening point of at least 75 ° C.
Cresol novolak type epoxy resin, softening point 60 ℃ or less
Phenol novolak type epoxy resin and softening point 6 above
Bisphenol A novolak epoxy resin at 0 ° C or higher
At least one resin selected from the group consisting of
3. The solder photoresist ink composition according to claim 2 . 4. A method according to claim 1, wherein the epoxy resin and the unsaturated monocarboxylic acid
The amount of dibasic acid anhydride reacted with the reaction product
Unsaturated monocarboxylic acid reacted with resin (0.4-1.
3. The solder photoresist according to claim 2, which is 0 mole times.
Ink composition. 5. A radically polymerizable unsaturated acyl group and a carboxylic acid
A carboxyl group of a resin having a sil group and a compound (E)
2. The reaction according to claim 1, wherein the reaction with
Ruder photoresist ink composition. 6. The solder photoresist ink composition according to claim 1, wherein the thermosetting resin as the component (D) is a bifunctional or higher epoxy resin.