JPH08272094A - Composition for soldering photoresist ink - Google Patents

Abstract

PURPOSE: To provide a compsn. having a long shelf life and satisfactory dil. alkali developability and excellent in performance as one-pack photoresist ink. CONSTITUTION: In this compsn. contg. a UV-curing resin, a photopolymn. initiator and a diluent, the UV-curing resin is obtd. by allowing a dibasic acid anhydride having a mol. wt. of <=120 and a dibasic acid anhydride having a mol. wt. of >=140 in a molar ratio of (3:7) to (7:3)to react simultaneously with a reactional product of a novolak type epoxy compd. with unsatd. monocarboxylic acid and the resin has been blended with a heat curing accelerator.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a composition for a solder photoresist ink. More specifically, the present invention is useful as a photoresist for a solder mask of a printed wiring board, a photoresist for copper etching when manufacturing a printed wiring board, and a photosensitive resin for character ink for patterning by light irradiation. And has good storage stability and can be used as a one-pack composition,
The present invention relates to a composition for a solder photoresist ink which gives a cured product having excellent dilute alkali developability, heat resistance, electrical insulation and moisture resistance.

[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. As such a composition for a solder photoresist ink, for example, a UV curable product obtained by reacting a reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic acid anhydride A first liquid component consisting of a resin, a photopolymerization initiator and a diluent, and a second liquid component consisting of a thermosetting component and a diluent which are epoxy compounds having two or more epoxy groups in one molecule are used. A two-pack composition used immediately before mixing is known (Japanese Patent Publication No. 1-5).
4390 publication). The composition for a solder photoresist ink obtained by mixing the two liquids is applied to a printed wiring board, the coating surface is made tack-free by a temporary drying step, and then UV exposure is performed using a photomask to dilute the alkali. The unexposed portion is removed by developing with an aqueous solution, and the exposed portion is completely thermoset by heating.
However, since the above-mentioned solder photoresist ink composition contains a highly reactive unsaturated bond, a carboxyl group and a photopolymerization initiator in the same liquid, the compound having an epoxy group is blended only immediately before use. I can't. That is, such a composition has no choice but to be used as a two-component resist ink, which complicates the process of manufacturing a printed wiring board, which is a major obstacle to improving production efficiency. Further, a composition for a solder photoresist ink containing these ultraviolet curable resins,
It also has a drawback that the pot life is not always sufficient and the use is restricted. When the one-component type resist ink is prepared by removing the epoxy compound which is the second liquid component from the above-mentioned composition for solder photoresist ink, the solder photoresist cured film having adhesiveness, heat resistance, electric insulation, moisture resistance and the like. As a result, various performances that should be reduced are reduced. In addition, adjusting the type and blending amount of polybasic acid anhydride or photopolymerization initiator to improve the pot life leads to a very low dilute alkali developability, resulting in both pot life and dilute alkali developability. It was difficult to get it done. Therefore, the solder photoresist ink has good storage stability, can be used as a one-pack type resist ink, has good developability with a dilute alkaline aqueous solution, and has excellent mechanical and chemical properties of a cured product. A composition for use is desired.

[0003]

DISCLOSURE OF THE INVENTION The present invention improves the storage stability of a composition for a dilute alkaline developing type solder photoresist ink containing a conventional ultraviolet curable resin, and provides an ultraviolet curable resin, a photopolymerization initiator, Has a long shelf life as a one-part composition containing a diluent and a heat curing accelerator,
It has good dilute alkali developability after exposure and excellent adhesion of cured products to substrates, heat resistance, electrical insulation, and moisture resistance.
The purpose of the present invention is to provide a composition for liquid type solder photoresist ink.

[0004]

As a result of intensive studies to solve the above problems, the present inventors have found that the reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid contains two or more kinds of compounds. A composition containing an ultraviolet curable resin obtained by simultaneously reacting a dibasic acid and a thermosetting accelerator has excellent storage stability and dilute alkali developability, and the cured product has good mechanical and chemical properties. Found to have characteristics,
Based on this finding, the present invention has been completed. That is, the present invention provides (1) a solder photoresist ink composition containing an ultraviolet curable resin, a photopolymerization initiator and a diluent, wherein the ultraviolet curable resin is a novolac type epoxy compound and an unsaturated monocarboxylic acid. The dibasic acid anhydride having a molecular weight of 120 or less and the dibasic acid anhydride having a molecular weight of 140 or more are added to the reaction product of (3) in a molar ratio of 3/7 to 7/3.
The composition for a solder photoresist ink, which is obtained by reacting at the same time in a ratio such that the composition further comprises a thermosetting accelerator,
(2) The composition for a solder photoresist ink according to item (1), wherein the average number of phenol nuclei of the novolac type epoxy compound is 5 to 7 nuclei, (3) the ultraviolet curable resin is a novolac type Per 1 mol of the hydroxyl group possessed by the reaction product of the epoxy compound and the unsaturated monocarboxylic acid,
The composition for a solder photoresist ink according to (1) to (2), which is obtained by reacting 0.4 to 1.0 mol of a dibasic acid anhydride, and (4) an ultraviolet curable resin are 45 ~ 100
The composition for a solder photoresist ink according to any one of (1) to (3), which has an acid value of mgKOH / g, and (5) the amount of the photopolymerization initiator compounded is 100 parts by weight of the ultraviolet curable resin. 0.2 to 20.0 parts by weight of the composition for a solder photoresist ink according to (1) to (4) and (6) a diluent are selected from organic solvents and photopolymerizable monomers. At least one kind, and the compounding amount thereof is 30 to 200 parts by weight per 100 parts by weight of the ultraviolet curable resin.
The composition for solder photoresist ink according to (1) to (5), and (7) the heat curing accelerator is a triazine compound or an adduct of a triazine compound and isocyanuric acid, and the compounding amount thereof is UV curing. The present invention provides a composition for a solder photoresist ink according to items (1) to (6), which is 0.5 to 30 parts by weight per 100 parts by weight of the organic resin.

The composition for a solder photoresist ink of the present invention is a composition containing an ultraviolet curable resin, a photopolymerization initiator and a diluent, and a thermal curing accelerator added thereto. The ultraviolet curable resin used in the present invention is a reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid, and a dibasic acid anhydride having a molecular weight of 120 or less and a dibasic acid anhydride having a molecular weight of 140 or more, It is obtained by simultaneously reacting two dibasic acid anhydrides in a molar ratio of 3/7 to 7/3. The novolac type epoxy compound used is a polyfunctional epoxy compound obtained by reacting epichlorohydrin with phenol novolac or cresol novolac, which is a reaction product of phenol or o-cresol and formaldehyde, and has a phenol nucleus having a nucleus number of Those having an average of 5 to 7 nuclei and an epoxy equivalent of 170 to 230 can be preferably used. The number of phenolic nuclei is 5
If it is less than the nucleus, the cured product of the composition for a solder photoresist ink may become brittle. When the number of nuclei of phenol nuclei exceeds 7, the dilute alkali developability of the composition for solder photoresist ink may decrease. In the present invention, a novolac type epoxy compound is reacted with an unsaturated monocarboxylic acid. The reaction between the epoxy group and the carboxyl group opens the oxirane ring to form a hydroxyl group and an ester bond. The unsaturated monocarboxylic acid used is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, crotonic acid, vinyl acetic acid, sorbic acid, cinnamic acid, etc. Acrylic acid has good photopolymerizability of the product. Since the cured product has excellent properties, it can be used particularly preferably. There is no particular limitation on the reaction method of the novolac type epoxy compound and the unsaturated monocarboxylic acid, for example,
The novolac type epoxy compound and the unsaturated monocarboxylic acid can be reacted by heating in a suitable diluent. Examples of the diluent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, isopropanol and cyclohexanol; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; Petroleum solvents such as petroleum ether and naphtha; cellosolves such as cellosolve and butyl cellosolve; carbitols such as carbitol and butyl carbitol;
Examples thereof include acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, and butyl carbitol acetate.

In the present invention, it is preferable that the amount of the epoxy group of the novolac type epoxy compound to react and the amount of the unsaturated monocarboxylic acid are substantially equivalent. If the epoxy group is excessive or the unsaturated monocarboxylic acid is excessive, the storage stability may be deteriorated and the properties of the cured product may be deteriorated. The reaction temperature of the novolac type epoxy compound and the unsaturated monocarboxylic acid is preferably 90 to 200 ° C, more preferably 100 to 130 ° C. In the reaction of the novolac type epoxy resin and the unsaturated monocarboxylic acid, in the reaction mixture consisting of the novolac type epoxy compound, the unsaturated monocarboxylic acid and the diluent,
The total amount of the novolac type epoxy compound and the unsaturated monocarboxylic acid is preferably 20 to 80% by weight. The reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid can be directly subjected to the reaction with the following dibasic acid anhydride as a diluent solution without isolation. The ultraviolet curable resin used in the present invention comprises a reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid, and a dibasic acid anhydride having a molecular weight of 120 or less and a dibasic acid anhydride having a molecular weight of 140 or more. The molar ratio of the seed dibasic anhydride is 3
It is obtained by simultaneously reacting at a ratio of / 7 to 7/3. As the dibasic acid anhydride, saturated dibasic acid anhydride and unsaturated dibasic acid anhydride can be used. Examples of the dibasic acid anhydride having a molecular weight of 120 or less include succinic anhydride, methylsuccinic anhydride, glutaric anhydride, maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, and diglycolic anhydride. Among these, succinic anhydride can be particularly preferably used. Examples of the dibasic acid anhydride having a molecular weight of 140 or more include allyl succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride. Acid, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride,
Examples thereof include diphenic anhydride, nitrophthalic anhydride, phthalonic anhydride, and of these, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and hexahydrophthalic anhydride can be particularly preferably used.

The dibasic acid anhydride reacts with the hydroxyl group contained in the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid to form an ester bond and a free carboxyl group. The state of the free carboxyl group formed here and the bond of the carboxyl group with the main chain skeleton has a strong influence on the dilute alkali developability, storage stability and properties of the cured coating film, and the molecular weight is 120 or less. The molar ratio of the dibasic acid anhydride and the dibasic acid anhydride having a molecular weight of 140 or more is 3/7 to
By simultaneously reacting in a ratio of 7/3, preferably reacting in a ratio of 4/6 to 6/4 at a molar ratio, an ultraviolet curable resin having good performance can be obtained. The molar ratio of the dibasic acid anhydride having a molecular weight of 120 or less to the dibasic acid anhydride having a molecular weight of 140 or more is 3
If it is less than / 7 and the ratio of the dibasic acid anhydride having a molecular weight of 120 or less is small, the dilute alkali developability may decrease. If the molar ratio of the dibasic acid anhydride having a molecular weight of 120 or less to the dibasic acid anhydride having a molecular weight of 140 or more exceeds 7/3 and the proportion of the dibasic acid anhydride having a molecular weight of 140 or more is small, Good physical properties may not be sufficiently expressed, and shelf life may be shortened. The dibasic acid anhydride having a small molecular weight has _a relatively low pKa value in a state of being added to the main chain of the reaction product, and has an effect of contributing to the improvement of dilute alkali developability. , pK _a value is relatively high in a state of being attached to the main chain of the reactants, suitable electrical properties are considered to have an effect contributing to heat resistance.

In the UV-curable resin used in the present invention, two kinds of dibasic acid anhydrides having different molecular weights are simultaneously added to the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid to react. Is important, and the composition for photoresist ink containing the ultraviolet curable resin thus obtained has excellent storage stability and good performance as a solder photoresist ink (photocurability, dilute alkali developability, Since it has good heat resistance, electrical insulation, and humidity resistance, and especially good dilute alkali developability, and shows good thermosetting property, it is necessary to add a thermosetting component (the most suitable is an epoxy compound). Instead, it can be used in a one-pack type. Even when three or more kinds of dibasic acid anhydrides are mixed and reacted after satisfying the above blending ratio, the resulting composition has good storage stability and dilute alkali developability. However, even if UV curable resins obtained by reacting two kinds of dibasic acid anhydrides with a reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid are mixed and blended later, A composition having both good storage stability and good dilute alkali developability cannot be obtained, and the thermosetting property is also poor. That is, in the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid,
In the case of sequentially reacting two kinds of dibasic acid anhydrides, a resin obtained by reacting a reaction product of a novolak type epoxy compound and an unsaturated monocarboxylic acid with a dibasic acid anhydride having a molecular weight of 120 or less is also used. The effect of the present invention is not obtained even when the reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid is mixed with a resin obtained by reacting a dibasic acid anhydride having a molecular weight of 140 or more. . The mechanism is not clear, but by reacting two kinds of dibasic acid anhydrides simultaneously, two or more kinds of chemically different carboxyl groups are generated in the same molecule in the UV curable resin, Therefore, it is considered that the excellent performance, which was not possible with the ultraviolet curable resin obtained by reacting a single dibasic acid anhydride, was developed for the first time.

In the production of the ultraviolet curable resin, one type of dibasic acid anhydride having a molecular weight of 120 or less can be used, and two or more types can be used in combination. Similarly, one type of dibasic acid anhydride having a molecular weight of 140 or more can be used, and two or more types can be used in combination. Even if the number of dibasic acid anhydrides used increases, the molar ratio of the dibasic acid anhydride having a molecular weight of 120 or less and the dibasic acid anhydride having a molecular weight of 140 or more is in the range of 3/7 to 7/3. Can be used in the composition of the present invention. In the ultraviolet curable resin used in the present invention, the amount of the dibasic acid anhydride reacted with the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid is the amount of the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid. It is preferably 0.4 to 1.0 mol per 1 mol of the hydroxyl group contained in the product. When the amount of the dibasic acid anhydride to be reacted is less than 0.4 mol per mol of the hydroxyl group contained in the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid, the dilute alkali developability and the coating film properties are improved. It may decrease. When the amount of the dibasic acid anhydride to be reacted exceeds 1.0 mol per 1 mol of the hydroxyl group contained in the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid, the unreacted dibasic acid anhydride in the reaction mixture is not reacted. Things remain and the performance of the cured coating deteriorates.

In the ultraviolet curable resin used in the present invention, a dibasic acid anhydride having a molecular weight of 120 or less and a molecular weight of 1
A dibasic acid anhydride of 40 or more is simultaneously added to the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid to react. When the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid exists as a solution of a diluent, a mixture of dibasic acid anhydrides is added to this solution, and the mixture is heated and dissolved to react, so that it is preferable. The reaction can proceed. The reaction temperature of the reaction product of the novolac type epoxy compound and the unsaturated monocarboxylic acid with the dibasic acid anhydride is preferably 60 to 120 ° C., and 7
It is more preferably 0 to 90 ° C. The ultraviolet curable resin used in the present invention has an acid value of 45 to 100 mgKOH / g.
It is preferred that The acid value of the obtained ultraviolet curable resin can be easily adjusted by appropriately selecting the amount of the dibasic acid anhydride that reacts. When the acid value of the ultraviolet curable resin is less than 45 mgKOH / g, the diluted alkali developability of the resist composition and the adhesion and heat resistance of the cured coating film may be deteriorated. Acid value of UV curable resin is 1
If it exceeds 00 mgKOH / g, the electric insulation of the cured film,
The heat resistance and humidity resistance may be poor. The composition for solder photoresist ink of the present invention contains a photopolymerization initiator. The photopolymerization initiator to be used is not particularly limited, and a conventionally known one that decomposes to generate a radical upon irradiation with light, for example, benzoins, benzophenones, acetophenones, anthraquinones, xanthones, thioxanthones or ketals. One or more selected from the above are used. Further, these can be used in combination with a known photopolymerization accelerator such as benzoic acids or tertiary amines. The preferable range of the amount of the photopolymerization initiator is 0.2 to the ultraviolet curable resin.
It is 20.0% by weight, preferably 2.0 to 10.0% by weight. The compounding amount of the photopolymerization initiator is 100
If the amount is less than 0.2 parts by weight per part by weight, it may take a long time to cure the composition for a solder photoresist ink. When the compounding amount of the photopolymerization initiator exceeds 20.0 parts by weight per 100 parts by weight of the ultraviolet curable resin, the performance of the cured coating film may deteriorate.

The solder photoresist ink composition of the present invention contains a diluent. As the diluent, an organic solvent or a photopolymerizable monomer can be used. When an organic solvent is used as the diluent, the reaction between the novolac type epoxy compound and the unsaturated monocarboxylic acid, and the diluent used for the synthesis of the ultraviolet curable resin by the reaction of the dibasic acid anhydride are the same as the solder photoresist. It can be used as a diluent for an ink composition. If necessary, an organic solvent may be further added to give a composition having an appropriate concentration. Examples of the photopolymerizable monomer include 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 Monofunctional acrylate compounds represented by (meth) acrylate and ethylcarbitol (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, glycerin diglycidyl ether di (meth) acrylate, glycerin triglycidyl ether (Meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyfunctional epoxy acrylates and the like. Examples thereof include functional acrylates. Here, (meth) acrylate indicates both acrylate and methacrylate.

In the solder photoresist ink composition of the present invention, the compounding amount of the diluent comprising an organic solvent or a photopolymerizable monomer is preferably 30 to 200 parts by weight per 100 parts by weight of the ultraviolet curable resin. . The organic solvent not only functions as a solvent when synthesizing an ultraviolet curable resin, but is also used for forming a film by applying a solder photoresist ink composition onto a printed wiring board and then drying the composition. The photopolymerizable monomer is used for diluting the composition for a solder photoresist ink so as to have a viscosity that makes it easy to apply, and also for promoting photopolymerizability. When the blending amount of the diluent is less than 30 parts by weight per 100 parts by weight of the ultraviolet curable resin, the viscosity of the solder photoresist ink composition is high, and it may be difficult to apply the composition to a printed wiring board. If the amount of the diluent added exceeds 200 parts by weight per 100 parts by weight of the ultraviolet curable resin, the viscosity of the composition for solder photoresist ink becomes too low, making it difficult to apply. If the diluent is an organic solvent, It takes time to dry to tack-free, and when the diluent is a photopolymerizable monomer, the performance of the cured coating film may deteriorate. The composition for solder photoresist ink of the present invention contains a thermosetting accelerator. The thermosetting accelerator accelerates the thermosetting reaction of the carboxyl groups and hydroxyl groups present in the ultraviolet curable resin, reduces the amount of these functional groups, and increases the crosslink density of the cured resin. As a result, the adhesion, heat resistance, electrical insulation, and moisture resistance, which are essential performances of the solder resist, are improved. A typical example of the heat curing accelerator is 2,4-diamino-6-vinyl-s-triazine [Shikoku Chemicals Co., Ltd., Cureazole VT], 2,4-diamino-6 {2'-methylimidazolyl-. (1) '} ethyl-s
-Triazine / isocyanuric acid adduct [Shikoku Kasei Co., Ltd.,
Cureazole 2MA-OK], 2,4-diamino-6-
Methacryloyloxyethyl-s-triazine, 2,4
Examples thereof include vinyltriazine-based compounds such as -diamino-6-vinyl-s-triazine / isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-s-triazine / isocyanuric acid adduct. The thermosetting accelerators may be used alone or in combination of two or more. The blending amount thereof is preferably 0.5 to 30 parts by weight, and 1 to 100 parts by weight of the ultraviolet curable resin.
It is more preferably 5 parts by weight. When the blending amount of the thermosetting accelerator is less than 0.5 part by weight per 100 parts by weight of the ultraviolet curable resin, the adhesiveness and heat resistance of the cured coating film tend to be lowered. If the blending amount of the thermosetting accelerator exceeds 30 parts by weight per 100 parts by weight of the ultraviolet curable resin, the proportion of impurities remaining in the coating film after the thermosetting will increase, and as a result, the moisture resistance and the electrical insulation properties will increase. descend.

The composition for the solder photoresist ink of the present invention contains, if necessary, known fillers such as barium sulfate and silicon oxide, and known coloring agents such as phthalocyanine green, phthalocyanine blue, titanium dioxide and carbon black. Various additives such as pigments, defoaming agents and leveling agents, or known polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, pyrogallol and t-butylcatechol can be added.
The composition for the solder resist ink of the present invention, for example,
It is applied on the entire surface by a screen printing method, a roll coater method, a spray method, or a curtain coater method on a printed wiring board, dried at 65 to 80 ° C to remove tackiness on the surface, and then a photomask or the like is used. Mask unnecessary portions and perform photo-curing. A solder resist film is obtained by dissolving the unexposed portion with a dilute aqueous alkali solution and further heat curing. For photocuring the composition for solder photoresist ink of the present invention, as an irradiation light source,
Low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, super-high pressure mercury lamp,
A known light source such as a xenon lamp or a metal halide lamp can be used.

[0014]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The shelf life of the ultraviolet curable resin, the developability of the composition and the coating film performance were evaluated by the following methods. (1) UV-curable resin shelf-life acceleration test Put the UV-curable resin in a plastic bottle with a lid and immerse it in a constant temperature bath at 60 ° C. The viscosity at 25 ° C reaches 2.5 times the initial viscosity. Alternatively, it was evaluated by the number of days until it exceeded 1,000 poise. (2) Dilute Alkali Developability In the process of manufacturing a printed wiring board for testing, the developability when developed by stirring with a stirrer at 20 ° C. for 5 minutes using a 1 wt% sodium carbonate aqueous solution as a developer after curing by light irradiation is as follows. It evaluated by the criteria shown in. ◎: Development is possible within 1 minute. ◯: Development is possible in over 1 minute and within 3 minutes. Δ: Development is possible in more than 3 minutes and within 5 minutes. X: Development is impossible within 5 minutes. In order to evaluate the stability of the solder photoresist ink in the tentatively dried state, tentative drying was performed at 75 ° C. for 30 minutes, and the developability was evaluated both immediately after and 3 days after tentative drying. (3) Adhesion According to JIS K 5400 8.5.2, put 10 crosscuts in a grid pattern on each test printed wiring board, and then peel off the coating film after the peeling test with cellophane tape. The state was visually determined. A: 100/100 with no peeling observed. ◯: 100/100 with a slight line edge. Δ: 90/100 to 99/100. X: 0/100 to 89/100. (4) Pencil hardness According to JIS K 5400 8.4.2, "Mitsubishi Uni"
The pencil was used for evaluation with the highest hardness without scratching the coating film. (5) Solder heat resistance Rosin flux [Asahi Chemical Laboratory Co., Ltd., trade name GX-7] is applied to the printed wiring board for testing, and the coating surface is contacted with solder in a solder bath kept at 260 ° C. As described above, the film was floated for 15 seconds, and then swelling and peeling of the coating film were observed. This was defined as one cycle, and evaluation was made by the total time until swelling or peeling occurred. (6) Water-soluble flux resistance Water-soluble flux [LONCO, trade name CF-350] was applied to each test printed wiring board, and the coating film surface was brought into contact with the solder in a solder bath at 260 ° C. After floating for 5 seconds and further immersing in warm water at 60 ° C. for 15 minutes, a peeling test was performed using cellophane tape. At the same time, the change in gloss on the surface of the coating film, especially the whitening state, was observed. The evaluation criteria are shown below. Peeling test ◎: It does not peel at all. ○: Slightly peeled off. Δ: 10 to 30% of the whole is peeled off. X: 31% or more of the total peeled off. Whitening state ◎: No whitening at all. ○: Only slightly whitened. Δ: 10 to 30% of the whole is whitened. ×: 31% or more of the whole is whitened. (7) Electrical Insulation Test According to JIS Z 3197, the SM of the initial insulation of each test printed wiring board and the insulation after being left at 60 ° C. and 90% relative humidity for 500 hours were measured.
It was evaluated as a 1-minute value at DC500V using -8210 [manufactured by Toa Denpa Co., Ltd.].

Production Example 1 (Production of UV curable resin) 1 equipped with a stirrer, reflux condenser, dropping funnel and thermometer
A liter separable flask was charged with 188 g of ethyl carbitol acetate and 215 g of a cresol novolac type epoxy resin having an epoxy equivalent of 215 and having an average of 6 phenol nuclei in one molecule. The mixture was heated to 120 ° C. with stirring, and 72 g (1.0 mol) of acrylic acid was added dropwise from the dropping funnel over 1 hour while maintaining 120 ° C., and the reaction was continued at 120 ° C. for 10 hours. Once the reaction mixture has cooled to room temperature, 25% succinic anhydride
g (0.25 mol) and tetrahydrophthalic anhydride 38
g (0.25 mol) was added, and the mixture was again heated to 80 ° C. and reacted for 3 hours. After the reaction was completed, the mixture was cooled to room temperature to obtain a viscous solution. The heating residue of this solution is 65
% By weight and showed an acid value of 53 mg KOH / g as a solution. This solution is named resin A-1. Production Example 2 (Production of UV-Curable Resin) 188 g of butyl cellosolve was used instead of 188 g of ethyl carbitol acetate of Production Example 1, and 25 g of succinic anhydride and 38 g of tetrahydrophthalic anhydride were used, and 30 g of succinic anhydride (0. 3 mol) and 33 g (0.2 mol) of methyltetrahydrophthalic anhydride were used, and the same operation as in Production Example 1 was repeated. The heating residue of the obtained viscous solution was 65% by weight, and
An acid value of mgKOH / g was shown. This solution is named resin A-2. Reference Example 1 (Production of UV curable resin) The amount of ethyl carbitol acetate of Production Example 1 was 181.
g, and the same operation as in Production Example 1 was repeated except that 50 g (0.5 mol) of succinic anhydride was used instead of 25 g of succinic anhydride and 38 g of tetrahydrophthalic anhydride. The heating residue of the resulting viscous solution was 65% by weight and showed an acid value of 57 mg KOH / g as a solution. This solution is named resin A-3. Reference Example 2 (Production of UV curable resin) The amount of ethyl carbitol acetate of Production Example 1 was changed to 204
g of tetrahydrophthalic anhydride instead of 25 g of succinic anhydride and 38 g of tetrahydrophthalic anhydride.
The same operation as in Preparation Example 1 was repeated except that g (0.6 mol) was used. The viscous solution thus obtained had a heating residue of 65% by weight and showed an acid value of 59 mgKOH / g as a solution. This solution is named resin A-4. Reference Example 3 (Production of UV curable resin) Resin A-3 and resin A-4 were mixed at a weight ratio of 1: 1. The heating residue of the obtained viscous solution was 65% by weight, and the solution was 58 mgKOH.
The acid value was / g. This solution is designated as resin A-5. Reference Example 4 (Production of UV curable resin) The amount of ethyl carbitol acetate in Production Example 1 was 191.
g, and instead of 25 g of succinic anhydride and 38 g of tetrahydrophthalic anhydride, 45 g of succinic anhydride (0.45
Mole) and 23 g of tetrahydrophthalic anhydride (0.15
The same operation as in Production Example 1 was repeated except that the amount of (mol) was used. The viscous solution thus obtained had a heating residue of 65% by weight and showed an acid value of 62 mgKOH / g as a solution. This solution is named resin A-6.

Example 1 55 g of ultraviolet curable resin A-1, 3 g of a photopolymerization initiator [Ciba Geigy, Irgacure 907], a photopolymerization initiator [Nippon Kayaku Co., Ltd., Cayacure DETX-S].
1 g, 5 g of trimethylolpropane triacrylate as a diluent, 0.5 g of an imidazole-based thermosetting accelerator [Shikoku Chemicals Co., Ltd., Cureazole 2MA-OK], 3 g of phthalocyanine green pigment, 12 g of barium sulfate, 10 g of silicon oxide and a quenching agent. 0.5 g of foaming agent [Nippon Kagaku KK, Formlex SOL-30] was kneaded by a roll mill (three rolls) to prepare a composition for a solder photoresist ink. A copper printed wiring board 2 having a pattern formed by previously etching this composition.
The film was applied on the entire surface by a screen printing method to a film thickness of 15 to 20 μm, and was temporarily dried at 75 ° C. for 30 minutes in a hot air circulation type drying furnace. Immediately after tentative drying, a photomask is applied to one of the substrates and a UV light of 3
It was irradiated with J / cm ² to perform photocuring. Then, a 1 wt% sodium carbonate aqueous solution was used as a developing solution to remove the uncured portion of the coating film. The developed substrate is further heated at 150 ° C for 3
Thermal curing was performed for 0 minutes to complete a test printed wiring board. The other one of the test substrates was exposed to ultraviolet rays under the above conditions 3 days after the preliminary drying, similarly developed with an aqueous sodium carbonate solution, and further thermally cured. The developability immediately after provisional drying and the developability 3 days after provisional drying were evaluated. The performance of the coating film was evaluated using a test printed wiring board that had been exposed and developed immediately after provisional drying. The results are shown in Table 2. Example 2 A test printed wiring board was prepared by repeating the same operation as in Example 1 except that the resin A-2 was used as the ultraviolet curable resin. The diluted alkali developability and coating film performance were evaluated, and the results are shown in Table 2. Example 3 Cureazole 2MA as an imidazole-based thermosetting accelerator
-Instead of OK, Curesol VT [Shikoku Kasei
The same operation as in Example 1 was repeated, except that the test printed wiring board was prepared. The diluted alkali developability and coating film performance were evaluated, and the results are shown in Table 2. Comparative Example 1 A test printed wiring board was prepared by repeating exactly the same operations as in Example 1 except that Resin A-3 was used as the ultraviolet curable resin. The diluted alkali developability and coating film performance were evaluated, and the results are shown in Table 2. Comparative Example 2 A test printed wiring board was prepared by repeating exactly the same operations as in Example 1 except that Resin A-4 was used as the ultraviolet curable resin. The diluted alkali developability and coating film performance were evaluated, and the results are shown in Table 2. Comparative Example 3 A test printed wiring board was prepared by repeating exactly the same operation as in Example 1 except that Resin A-5 was used as the ultraviolet curable resin. The diluted alkali developability and coating film performance were evaluated, and the results are shown in Table 2. Comparative Example 4 A test printed wiring board was prepared by repeating exactly the same operations as in Example 1 except that Resin A-6 was used as the ultraviolet curable resin. The diluted alkali developability and coating film performance were evaluated, and the results are shown in Table 2. Comparative Example 5 Except that no imidazole-based thermosetting accelerator was added,
The same operation as in Example 1 was repeated to prepare a test printed wiring board. The diluted alkali developability and coating film performance were evaluated, and the results are shown in Table 2. Comparative Example 6 A test was performed on a two-component solder photoresist ink composition. 55 g of UV curable resin A-4, a photopolymerization initiator [Ciba Geigy, Irgacure 907] 3
g, photopolymerization initiator [Nippon Kayaku Co., Cayacure
DETX-S] 1 g, trimethylolpropane triacrylate 5 g as a diluent, imidazole-based thermosetting accelerator [Shikoku Chemicals Co., Ltd., Cureazole 2MA-OK]
0.5 g, phthalocyanine green pigment 3 g, barium sulfate 12 g, silicon oxide 10 g and defoaming agent [Nichika Kagaku]
0.5 g of Folexlex SOL-30] manufactured by K.K. was kneaded by a roll mill (3 rolls) to prepare a first liquid of a composition for a solder photoresist ink. 10 g of o-cresol novolac epoxy resin [Toto Kasei Co., Ltd., YDCN-702S] was mixed as the second liquid component with the above first liquid, and kneading was continued by a roll mill (three rolls) to obtain a solder photoresist. An ink composition was prepared. Using the obtained solder photoresist ink composition, a test printed wiring board was prepared in the same manner as in Example 1. The diluted alkali developability and coating film performance were evaluated, and the results are shown in Table 2.

[0017]

[Table 1]

[Note] 1) A photopolymerization initiator manufactured by Ciba Geigy. 2) Photopolymerization initiator manufactured by Nippon Kayaku Co., Ltd. 3) An imidazole-based thermosetting accelerator manufactured by Shikoku Chemicals Co., Ltd. 4) Defoaming agent manufactured by Nika Kagaku Co., Ltd. 5) o-cresol novolac type epoxy resin manufactured by Tohto Kasei Co., Ltd.

[0019]

[Table 2]

The UV-curable resins produced in Production Examples 1 and 2 used in the present invention have a long shelf life in the accelerated test and show good storage stability. On the other hand, the ultraviolet curable resins of Reference Examples 1 and 4 in which the amount of the dibasic acid anhydride having a molecular weight of 120 or less is large, and the molecular weight of 12
It can be seen that the ultraviolet curable resin of Reference Example 3 in which a resin having a large amount of 0 or less dibasic acid anhydride used is blended has a short shelf life in an accelerated test and is poor in storage stability. The composition for a solder photoresist ink of the present invention has excellent dilute alkali developability immediately after provisional drying, and exhibits excellent or good dilute alkali developability even after 3 days of provisional drying. The composition for the solder photoresist ink of Comparative Example 1 using the UV-curable resin produced using only succinic anhydride having a molecular weight of 100 has poor dilute alkali developability after 3 days of temporary drying, and has a solder heat resistance. Inferior in electrical insulation and electrical insulation. The composition for the solder photoresist ink of Comparative Example 2 using the UV-curable resin produced using only tetrahydrophthalic anhydride having a molecular weight of 152 has poor dilute alkali developability, adhesion, pencil hardness and solder heat resistance. Inferior in water resistance and water resistance. The composition for the solder photoresist ink of Comparative Example 3 using the composition of the ultraviolet curable resin manufactured only by using succinic anhydride and the ultraviolet curable resin manufactured by using only tetrahydrophthalic anhydride was UV cured. Although the ratio of the amount of succinic anhydride and the amount of tetrahydrophthalic anhydride in the organic resin is within the scope of the present invention, since they are not reacted at the same time, they are inferior in dilute alkali developability and adhere to each other. sex,
Poor solder heat resistance and electrical insulation. The composition for the solder photoresist ink of Comparative Example 4 using the UV-curable resin produced by using succinic anhydride and tetrahydrophthalic anhydride in a molar ratio of 75/25 is the composition of the succinic anhydride in the UV-curable resin. Since the amount is too large as compared with the amount of tetrahydrophthalic anhydride, the developability of diluted alkali after 3 days of temporary drying is poor, and the adhesiveness, solder heat resistance, and electrical insulation are poor. The solder photoresist ink composition of Comparative Example 5 containing no thermosetting accelerator was inferior in all of adhesion, pencil hardness, solder heat resistance, water-soluble flux resistance, and electric insulation, and the composition of the present invention was not heated. It can be seen that the composition of the curing accelerator is an essential component. The conventional two-component solder photoresist ink composition of Comparative Example 6 was inferior to the composition of the present invention in dilute alkali developability immediately after tentative drying and after 3 days of tentative drying. There is.

[0021]

The composition for a solder photoresist ink of the present invention does not require the use of a two-component component such as a thermosetting resin and exhibits excellent performance as a one-component photoresist ink. Moreover, the composition for a solder photoresist ink of the present invention has both a long shelf life and good dilute alkali developability. Further, the cured coating film of the composition for a solder photoresist ink of the present invention has adhesion,
It has excellent heat resistance, electrical insulation, and moisture resistance, and exhibits the same or better performance as the cured coating film of the conventional two-component solder photoresist ink composition. Furthermore, the composition for a solder photoresist ink of the present invention is applied to a printed wiring board and temporarily dried, and then retains a good dilute alkali developability for a long time, and works after the temporary drying in the manufacturing process of the printed wiring board. Can be suspended. By virtue of this feature and the one-pack type ink, the composition for solder photoresist ink of the present invention has the effect of greatly improving the production efficiency in the production of printed wiring boards on holidays.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H05K 3/06 H05K 3/06 H 3/28 3/28 D (72) Inventor Kimihiro Makino Fukui Prefecture 32-18 No. 18 Shimonoda-machi, Sabae-shi 5 (72) Isao Moshioka 656 Utsuki-cho, Hachioji-shi, Tokyo 656 Asahi Chemical Research Institute Utsuki Plant (72) Kunihiko Ito 656, Utsuki-cho, Hachioji-shi, Tokyo Sahi Chemical Research Institute Utsugi Plant (72) Inventor Hitoshi Hashimoto 656 Utsugi-cho, Hachioji-shi, Tokyo Asahi Chemical Research Institute Utsugi Plant (72) Inventor Iwasa Yamadai 656 Utsuki-cho, Hachioji-shi, Asahi Chemical Co., Ltd. 656 Research Institute Utsugi Plant (72) Inventor Yoichi Oba 656 Utsugicho, Hachioji City, Tokyo Asahi Chemical Research Institute Utsugi Plant

Claims (7)

[Claims] 1. A solder photoresist ink composition containing an ultraviolet curable resin, a photopolymerization initiator and a diluent, wherein the ultraviolet curable resin is a reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid. And a dibasic acid anhydride having a molecular weight of 120 or less and a dibasic acid anhydride having a molecular weight of 140 or more at a molar ratio of 3/7 to 7/3, are obtained by simultaneously reacting, A composition for a solder photoresist ink, which further comprises a thermosetting accelerator. 2. The composition for a solder photoresist ink according to claim 1, wherein the novolac type epoxy compound has an average number of phenol nuclei of 5 to 7 nuclei. 3. The ultraviolet curable resin is reacted with 0.4 to 1.0 mol of a dibasic acid anhydride per 1 mol of a hydroxyl group contained in a reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid. The composition for a solder photoresist ink according to claim 1, wherein the composition is a solder photoresist ink. 4. The ultraviolet curable resin is 45 to 100 mg KOH.
The composition for a solder photoresist ink according to claims 1 to 3, which has an acid value of / g. 5. The composition for a solder photoresist ink according to claim 1, wherein the compounding amount of the photopolymerization initiator is 0.2 to 20.0 parts by weight per 100 parts by weight of the ultraviolet curable resin. 6. The diluent is at least one selected from organic solvents and photopolymerizable monomers, and the compounding amount thereof is 30 to 20 per 100 parts by weight of the ultraviolet curable resin.
It is 0 weight part, The composition for solder photoresist inks of Claims 1-5. 7. A thermosetting accelerator is a triazine compound or an adduct of a triazine compound and isocyanuric acid, and the compounding amount thereof is 0.1 per 100 parts by weight of an ultraviolet curable resin.
The composition for a solder photoresist ink according to claim 1, which is 5 to 30 parts by weight.