TWI689558B - White active energy ray curable resin composition - Google Patents

Abstract

An object of the present application is to provide a white active energy ray curable resin composition, which can form a cured product after a photocuring step, and has basic characteristics such as solder heat resistance, adhesion and coating film hardness, even without a further thermosetting step.

The present application provides a white line active energy ray curable resin composition, comprising a reactive polycarboxylic acid compound (A), a reactive compound (B) other than the (A), a photopolymerization iniciator (C), and titanium oxide (D), wherein the reactive polycarboxylic acid compound (A) is obtained from a reaction of a reactant (E) with a polybasic acid anhydride (d), and the reactant (E) contains an epoxy resin (a) represented by the general formula (1), an acrylic acid (b), and a compound (c) having at least two or more hydroxyl groups and one or more carboxyl in one molecule.

Description

White active energy ray-curable resin composition

The present invention relates to an active energy ray-curable resin composition suitable for a coating material for covering a conductor circuit pattern formed on a substrate such as a printed wiring board, and a cured product obtained by curing the active energy ray-curable resin composition Covered products such as covered printed wiring boards.

Printed wiring boards are generally used to form conductor circuit patterns on a substrate, and electronic components are mounted on the circuit pattern land by soldering. The circuit parts other than the land are covered with a solder mask as a permanent protective film. In this way, when soldering electronic parts on the printed wiring board, the solder is prevented from attaching to unnecessary parts, and the circuit conductor is prevented from being directly exposed to the air and corroded by oxidation and humidity.

Conventionally, when a solder resist film having basic characteristics such as solder heat resistance and coating film hardness is to be formed on a printed wiring board, as described in Patent Document 1, a photo-hardening step and a thermo-hardening step are required. First, after applying an active energy ray-curable resin composition to a printed wiring board, it is preliminarily dried at a temperature of about 60 to 100° C. as necessary to form a coating film. Next, make the pattern with the translucent pattern other than the land that makes the circuit pattern A negative film is adhered to the active energy ray-curable resin composition, and the active energy ray (for example, ultraviolet rays) is irradiated and photo-cured. Furthermore, the non-exposed area is removed with a weak alkaline aqueous solution, and the coating film is developed. Finally, the coating film is thermally cured at a temperature of about 140 to 180°C, and the cured coating film of the active energy ray-curable resin composition is formed on the printed wiring board.

However, in such a conventional solder resist film forming method, since the photo-curing step and the thermo-curing step are performed, there is a problem that the productivity of the film-forming product is not improved. In addition, when forming a solder mask on a substrate with low heat resistance, there is a problem that the substrate quality is deteriorated due to the deformation of the substrate due to heat in the thermosetting step.

Patent Document 2 discloses that a resin composition containing an unsaturated group-containing polycarboxylic acid is suitable for a solder resist, but the white active energy ray-curable resin composition in which titanium oxide and the like are dispersed is not described at all.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2008-257044

[Patent Document 2] Japanese Patent No. 2704661

The present invention was created in view of the above circumstances, and the object of the present invention is to provide a white active energy ray-curable resin composition, After the photo-curing step, even if the thermo-curing step is not further performed, a cured product having basic characteristics such as solder heat resistance, adhesion, and coating film hardness can still be formed.

The present inventors have conducted in-depth studies to solve the aforementioned problems, and as a result, have found that a resin composition having a specific compound and composition can solve the aforementioned problems, and completed the present invention one by one.

That is, the present invention relates to the following (1) to (8):

(1) A white active energy ray-curable resin composition containing: a reactive polycarboxylic acid compound (A), a reactive compound (B) other than the reactive polycarboxylic acid compound (A), and a photopolymerization initiator (C), and titanium oxide (D), wherein the reactive polycarboxylic acid compound (A) is obtained by reacting the reactant (E) with the polybasic acid anhydride (d), and the reactant (E) is the general formula (E) 1) The epoxy resin (a) shown and a compound having at least one polymerizable ethylenically unsaturated group and at least one carboxyl group in one molecule (b) and at least two in one molecule if necessary The reactant of the compound (c) with the above hydroxyl group and more than one carboxyl group.

(式中，n表示0至2的正數)

(Where n is a positive number from 0 to 2)

(2) The white active energy ray-curable resin composition as described in (1) above, wherein the reactive polycarboxylic acid compound (A) is obtained by reacting the reactant (E) with the polybasic acid anhydride (d), The reactant (E) is an epoxy resin (a) represented by the general formula (1) and a compound (b) having one or more polymerizable ethylenically unsaturated groups and one or more carboxyl groups in one molecule and A reactant of compound (c) having at least two hydroxyl groups and one or more carboxyl groups in one molecule.

(3) The white active energy ray-curable resin composition as described in (1) or (2) above, wherein the photopolymerization initiator (C) is an acylphosphine photopolymerization initiator and a benzoyl group The oxime-based photopolymerization initiator has a compounding ratio of 2 to 100 parts by mass based on 1 part by mass of the benzoyl oxime-based photopolymerization initiator.

(4) The white active energy ray-curable resin composition as described in (1) or (2) above, wherein the photopolymerization initiator (C) is an acylphosphine-based photopolymerization initiator and a benzoyl group The oxime-based photopolymerization initiator has a compounding ratio of 3 to 50 parts by mass relative to 1 part by mass of the benzoyl oxime-based photopolymerization initiator.

(5) The white active energy ray-curable resin composition as described in (1) or (2) above Among them, the photopolymerization initiator (C) is an acylphosphine-based photopolymerization initiator and a benzoyloxime-based photopolymerization initiator, and its compounding ratio is relative to that of the benzoyloxime-based photopolymerization. The initiator is 1 part by mass and the acylphosphine photopolymerization initiator is 4 to 10 parts by mass.

(6) The white active energy ray-curable resin composition according to any one of (3) to (5) above, wherein the acylphosphine-based photopolymerization initiator is selected from 2,4,6-tri Methylbenzyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, bis(2,6-dimethylbenzyl) -More than one of the group consisting of -2,4,4-trimethyl-pentylphosphine oxide and (2,4,6-trimethylbenzyl)ethoxyphenylphosphine oxide, benzoyl The oxime-based photopolymerization initiator is selected from 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyl oxime)], 2-propanedione- More than one group consisting of 2-O-benzyl oxime and 1-phenyl-1,2-propanedione-2-O-benzyl oxime.

(7) A cured product which is a cured product of the white active energy ray-curable resin composition according to any one of (1) to (6).

(8) A printed wiring board having the cured film of the white active energy ray-curable resin composition according to any one of (1) to (6).

According to the aspect of the present invention, by formulating the reactive polycarboxylic acid compound (A), even if the thermal curing step is not performed after the light curing step by exposure, that is, by the exposure treatment by active energy rays, Available in reflectance, solder heat resistance, adhesion and coating hardness And other hardened products with excellent characteristics. In addition, in the aspect of the present invention, even if the thermal curing step is not performed after the photo-curing step, a cured product having many of the above characteristics can be obtained, so the production efficiency of the product (for example, a printed wiring board with a cured film) is improved .

Hereinafter, the present invention will be described in detail.

In the present invention, the reactive polycarboxylic acid compound (A) is obtained by reacting the reactant (E) with the polybasic acid anhydride (d), and the reactant (E) is an epoxy resin represented by the general formula (1) (a) Compounds with more than one polymerizable ethylenically unsaturated group and more than one carboxyl group in one molecule (b) and optionally at least two hydroxyl groups and more than one carboxyl group in one molecule Reactant of compound (c).

That is, the reactive polycarboxylic acid compound (A) of the present invention reacts the reactant (E) of the epoxy resin (a) and the compound (b) with the polybasic anhydride (d), or the epoxy resin ( a) The reactant (E) with the compound (b) and the compound (c) is further reacted with the polybasic acid anhydride (d).

In the present invention, the ethylenically unsaturated group and the hydroxyl group are introduced into the molecular chain by the esterification reaction of epoxy carboxylic acid, and the advantages of the present invention are exerted.

The epoxy resin (a) represented by the general formula (1) of the present invention is (4(4(1,1-bis(p-hydroxyphenyl)-ethyl)α,α-dimethylbenzyl) Phenol) (hereinafter referred to as phenol compound (PA1)) and epihalohydrin obtained by reaction. The epoxy resin of the present invention is shown in the following representative structure.

(式中，n表示0至2的正數)

(Where n is a positive number from 0 to 2)

The epoxy resin of the present invention is generally available as TECMO REVG3101L (manufactured by Printec), NC-6300C (manufactured by Nippon Kayaku), NC-6300H (manufactured by Nippon Kayaku), etc., but can also be obtained by the following manufacturing methods The compound of formula (1).

In addition, the epoxy resin (a) used in the present invention is more preferably solid at ordinary temperature. In the present invention, an epoxy resin (a) having a softening point of 50 to 100°C or a melting point of 50 to 190°C is generally used, preferably a softening point of 60 to 100°C or a melting point of 60 to 190°C. In addition, in the present invention, those having an epoxy equivalent of 130 to 500 g/eq., preferably 150 to 400 g/eq., more preferably 170 to 300 g/eq. can be used. When the epoxy equivalent is too small, it tends to be hard and brittle, and when the epoxy equivalent is too large, it is difficult to show the hardness and the glass transition point becomes lower.

Examples of the epihalohydrin used in the reaction of the phenol compound (PA1) and epihalohydrin include epichlorohydrin, α-methylepichlorohydrin, γ-methylepichlorohydrin, and epibromohydrin. Among the inventions, epichlorohydrin, which is relatively easy to obtain industrially, is preferred. The amount of epihalohydrin used is 1 mole relative to the hydroxyl group of the phenol compound (PA1), and is usually 2 to 15 moles, preferably 4 to 10 moles. use When the amount of epihalohydrin is excessive, not only the productivity is not good, but also the softening point of the manufactured epoxy resin is lowered, and it has no beneficial effect on the viscosity of the prepreg. In addition, when the amount of epihalohydrin is less than 2 moles, the value of n becomes large, and saponification becomes easy during production.

In the above epoxidation reaction, it is preferable to use alkali metal hydroxide. Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. In addition, as the alkali metal hydroxide, a solid substance or an aqueous solution thereof can be used. For example, when the alkali metal hydroxide is used in the form of an aqueous solution, the aqueous solution of the alkali metal hydroxide can be continuously added to the reaction system, and at the same time, the water and the water can be continuously removed under reduced pressure or normal pressure. The epihalohydrin is distilled off, liquid separation is performed and water is removed, and the epihalohydrin is continuously returned to the reaction system to perform the epoxidation reaction. In addition, when a solid shape is used, it is preferable to use a sheet-like material in view of problems such as ease of handling and solubility. The amount of the alkali metal hydroxide used is 1 mole relative to the hydroxyl group of the phenol compound (PA1), and is usually 0.90 to 1.5 moles, preferably 1.01 to 1.25 moles, and more preferably 1.01 to 1.15 moles.

In the above epoxidation reaction, in order to promote the reaction, it is also possible to use a fourth-grade ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride, or tetramethylphosphonium chloride, Four-level phosphonium salts such as tetramethylphosphonium bromide, trimethylbenzylphosphonium chloride, triphenylbenzylphosphonium chloride, and triphenylethylphosphonium bromide are added as catalysts. The use amount of these fourth-grade salts is relative to 1 mole of the hydroxyl group of the phenol compound (PA1), and is usually 0.1 to 15 g, preferably 0.2 to 10 g.

烷等醚類，二甲基碸、二甲基亞碸、二甲基咪唑啶酮等非質子性極性溶劑等來進行反應為較佳，特別以其光學特性來看，在本發明中以使用醇類及/或醚類為較佳。 In the above epoxidation reaction, in terms of the progress of the reaction, alcohols such as methanol, ethanol, isopropyl, tetrahydrofuran,

Ethers such as alkanes, aprotic polar solvents such as dimethyl sulfoxide, dimethyl sulfoxide, dimethylimidazolidone, etc., are preferred for the reaction, especially in terms of their optical properties, they are used in the present invention Alcohols and/or ethers are preferred.

When the above alcohols or ethers are used, the use amount thereof is usually 2 to 50% by mass, preferably 4 to 20% by mass, relative to the use amount of epihalohydrin. On the other hand, when the above-mentioned aprotic polar solvent is used, the amount of its use relative to the amount of epihalohydrin is usually 5 to 100% by mass, preferably 10 to 80% by mass.

In the above epoxidation reaction, the reaction temperature is usually 30 to 90°C, preferably 35 to 80°C. On the other hand, the reaction time is usually 0.5 to 10 hours, preferably 1 to 8 hours. The reaction of the present invention may be carried out under normal pressure or reduced pressure, and the reaction may be carried out under azeotropic dehydration conditions of water-epihalohydrin under reduced pressure. The reactants of the epoxidation reaction can be purified by removing epihalohydrin, solvent, etc. under water or after heating or without water washing under heating and reduced pressure. In addition, in order to produce an epoxy resin with less hydrolyzable halogen, it is preferable to dissolve the recovered reactant in a solvent such as toluene and methyl isobutyl ketone, and add alkali metals such as sodium hydroxide and potassium hydroxide The aqueous solution of the hydroxide performs the ring-closing reaction of the by-products, so that the ring-closing of the halohydrin belonging to the by-products is more reliable.

At this time, the amount of the alkali metal hydroxide used is usually 0.01 to 0.3 moles, preferably 0.05 to 0.2 moles relative to 1 mole of the hydroxyl group of the phenol compound (PA1) used in the epoxidation. The reaction temperature is usually 50 to 120°C, and the reaction time is usually 0.5 to 2 hours.

In the above-mentioned epoxidation reaction, after the reaction is completed, the generated salt is removed by filtration, water washing, etc., and then the solvent is distilled off under heating and reduced pressure to obtain an epoxy resin that can be used in the present invention. The epoxy resin obtained in this way also includes a part in which epoxy resin is added by its solvent or water, or a part in which halogen cannot be completely closed and a halogen remains.

The epoxy resin (a) obtained as a reaction product of the phenol compound (PA1) and epihalohydrin obtained in this way is preferably excellent in productivity and handleability and further satisfies any of the following to give the cured product high mechanical strength Conditions.

1. The epoxy equivalent is preferably 195 to 245 g/eq., more preferably 200 to 240 g/eq.

2. In the gel permeation chromatograph, phenol compounds (PA1) are connected to each other by epihalohydrin, which accounts for 30 area% or less, and for connecting 3, it accounts for 20 area% or less, preferably connection 2 Individuals accounted for less than 25% of the area, connecting 3 persons accounted for less than 15% of the area. The rest is the monomer of epoxy resin (a).

In the present invention, the compound (b) having one or more polymerizable ethylenically unsaturated groups and one or more carboxyl groups in one molecule is used to impart reactivity to active energy rays and react. The ethylenically unsaturated group and the carboxyl group are not limited as long as they each have one or more in the molecule. Examples of these include monocarboxylic acid compounds and polycarboxylic acid compounds.

Monocarboxylic acid compound having one carboxyl group in one molecule, for example: (meth)acrylic acid or crotonic acid, α-cyanocinnamic acid, cinnamic acid, or saturated or unsaturated dibasic acid and unsaturated group-containing The reactant of the monoglycidyl compound. Among the above, (meth)acrylics include, for example, (meth)acrylic acid, β-styrylacrylic acid, β-furfurylacrylic acid, (meth) Acrylic acid dimer, as a saturated or unsaturated dibasic acid anhydride and a molecule of a (meth)acrylic acid derivative having a hydroxyl group in one molecule, half esters of mole reaction products, as a saturated or unsaturated dibasic acid and (a Base) Monoglycidyl acrylate derivatives, etc. Mole reactant half esters, etc.

Then, the polycarboxylic acid compound having two or more carboxyl groups in one molecule can be exemplified as the equivalent molar reaction of a saturated or unsaturated dibasic acid anhydride with a (meth)acrylate derivative having multiple hydroxyl groups in one molecule Half esters of compounds, and half esters of mole reaction products such as saturated or unsaturated dibasic acids and glycidyl (meth)acrylate derivatives having a plurality of epoxy groups.

Among these, in terms of sensitivity when forming an active energy ray-curable resin composition, the best ones include: (meth)acrylic acid; a reaction product of (meth)acrylic acid and ε-caprolactone ; Or cinnamic acid. The compound (b) preferably has no hydroxyl group in the compound.

In the present invention, the compound (c) having at least two or more hydroxyl groups and one or more carboxyl groups in one molecule is used as a reactor for the purpose of introducing hydroxyl groups into the carboxylate compound, if necessary.

In the present invention, specific examples of the compound (c) having at least two hydroxyl groups and one or more carboxyl groups in one molecule include, for example, dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylol Polycarboxylic acid-containing monocarboxylic acids such as acetic acid, dimethylolvaleric acid, and dimethylolhexanoic acid. Particularly preferred examples include dimethylolpropionic acid.

Among these, when considering the stability of the reaction of the aforementioned epoxy resin (a) with the compound (b) and the compound (c), the compound (b) and the compound (c) It is preferably a monocarboxylic acid, and even when a monocarboxylic acid and a polycarboxylic acid are used in combination, the value represented by the total molar amount of monocarboxylic acid/the total molar amount of polycarboxylic acid is preferably 15 or more.

In this reaction, the total addition ratio of the total amount of carboxylic acids of the epoxy resin (a) and the compound (b) and the compound (c) used as needed should be appropriately changed depending on the application. That is, when all epoxide groups are esterified with carboxylic acid, since unreacted epoxy groups do not remain, the storage stability as a reactive epoxy carboxylate compound is high. At this time, only the reactivity caused by the introduced double bond is used.

On the other hand, by deliberately reducing the amount of carboxylic acid compound added and leaving unreacted residual epoxy groups, the reactivity caused by the introduced unsaturated bond and the remaining epoxy Reactions caused by radicals, such as polymerization and thermal polymerization caused by photocationic catalysts. However, at this time, care should be taken to review the storage and production conditions of the reactive epoxy carboxylate compound (E).

When producing a reactive epoxy carboxylate compound (E) that does not have an epoxy group remaining, the total amount of the compound (b) and the compound (c) used as needed is 1 equivalent to the epoxy resin (a) , Preferably 90 to 120 equivalent %. As long as it is within this range, it can be manufactured under more stable conditions. When the total addition amount of the compound (b) and the compound (c) used as needed is more than the aforementioned range, excessive amounts of the compound (b) and the compound (c) will remain, which is not preferable.

In addition, when the epoxy group is intentionally left, the total sum of the compound (b) and the compound (c) used as necessary is 1 to equivalent to the epoxy resin (a), preferably 20 to 90 equivalent%. If it exceeds this range, it will not It will fully proceed with further reactions caused by epoxy groups. In this case, it is necessary to pay sufficient attention to the saponification during the reaction and the stability over time of the reactive epoxy carboxylate compound (E).

When using the compound (b) and the compound (c) in the use ratio, with respect to the molar ratio of the carboxylic acid, the compound (b): the compound (c) is 95: 5 to 5: 95, and then preferably 95: 5 to 40: 60 range. As long as it is in this range, the sensitivity to active energy rays will be good, and sufficient hydroxyl groups may be introduced to react the reactive epoxy carboxylate compound (E) with the polybasic acid anhydride (d).

The carboxylic acid esterification reaction can be carried out without a solvent, or can be carried out by diluting with a solvent. Here, the usable solvent is not particularly limited as long as it is an inert solvent for the carboxylic acid esterification reaction.

The preferred amount of solvent used should be appropriately adjusted depending on the viscosity or use of the resulting resin, but it is preferably 90 to 30 parts by mass, more preferably 80 to 50 parts by mass relative to 100 parts by mass of the solid content. Way to use.

Specific examples include aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, and tetramethylbenzene; aliphatic hydrocarbon solvents such as hexane, octane, and decane; and Petroleum ether, white gasoline, solvent naphtha, etc. of the mixture, ester solvents, ether solvents, ketone solvents, etc.

Examples of ester solvents include alkyl acetates such as ethyl acetate, propyl acetate, and butyl acetate; cyclic esters such as γ-butyrolactone, ethylene glycol monomethyl ether acetate, and diethylene glycol Monomethyl ether monoacetate, diethylene glycol monoethyl ether monoacetate, triethylene glycol monoethyl ether monoacetate, diethylene glycol Alcohol monobutyl ether monoacetate, propylene glycol monomethyl ether acetate, butylene glycol monomethyl ether acetate and other mono- or polyalkylene glycol monoalkyl ether monoacetates; glutaric acid dioxane Alkyl esters, dialkyl succinate, dialkyl adipate and other polycarboxylic acid alkyl esters.

Examples of ether solvents include alkyl ethers such as diethyl ether and ethyl butyl ether; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether, and dipropylene glycol diethyl ether Glycol ethers such as ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether; cyclic ethers such as tetrahydrofuran.

Examples of ketone solvents include acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, cyclohexanone, and isophorone.

In addition to this, it may be carried out in a single or mixed organic solvent such as other reactive compounds (B) described later. In this case, when used as a curable composition, it can be directly used as a composition, which is preferable.

In order to promote the reaction during the reaction, it is preferable to use a catalyst, and the amount of the catalyst used relative to the reactant (that is, the epoxy resin (a), the carboxylic acid compound (b), and the compound (c) used as needed) And the total amount of reactants (such as the solvent and the like added) is 100 parts by mass, usually 0.1 to 10 parts by mass. The reaction temperature at this time is usually 60 to 150°C, and the reaction time is preferably 5 to 60 hours. Specific examples of catalysts that can be used include, for example, triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethyl iodide Known general alkaline catalysts such as ammonium ammonium, triphenylphosphine, triphenyl antimony hydride, methyl triphenyl antimony hydride, chromium octoate, zirconium octoate, and the like.

In addition, thermal polymerization inhibitors use hydroquinone monomethyl Ether, 2-methylhydroquinone, hydroquinone, diphenylpicrylhydrazine, diphenylamine, 3,5-di-tert-butyl-4-hydroxytoluene, etc. are preferred.

In the case of proper sampling, the acid value of this reaction system is 5mg. KOH/g or less, preferably 3mg. The time point below KOH/g is regarded as the end point.

The preferred molecular weight range of the reactive epoxy carboxylate compound (E) thus obtained is the polystyrene-equivalent weight average molecular weight measured by GPC in the range of 1,000 to 50,000, more preferably 2,000 to 30,000.

When the molecular weight is less than this, the strength and toughness of the hardened product are not fully exerted, while if it is larger than this, the viscosity becomes high, making coating difficult.

Next, the acid addition step will be described in detail. The acid addition step is carried out for the purpose of introducing the carboxyl group into the reactive epoxy carboxylate compound (E) obtained in the previous step and obtaining the reactive polycarboxylic acid compound (A). That is, the hydroxyl group produced by the esterification reaction of the carboxylic acid and the polybasic acid anhydride (d) undergo an addition reaction, thereby introducing a carboxyl group via an ester bond.

Specific examples of the polybasic acid anhydride (d) can be used as long as it has, for example, a compound having an acid anhydride structure in the molecule, and is preferably succinic anhydride or phthalic anhydride, which is excellent in alkaline aqueous solution developability, heat resistance, hydrolysis resistance, etc. , Tetrahydrophthalic anhydride, hexahydrophthalic anhydride, itaconic anhydride, 3-methyl-tetrahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, trimesic acid Anhydride or maleic anhydride.

The reaction of adding polybasic acid anhydride (d) can be done by The polycarboxylic acid anhydride (d) is added to the carboxylic acid esterification reaction liquid to proceed. The amount of addition should be appropriately changed according to the purpose.

The addition amount of the polybasic acid anhydride (d), for example, when the reactive polycarboxylic acid compound (A) of the present invention is to be used as a basic developing type photoresist, it is preferable to use the reactive polycarboxylic acid compound finally obtained The acid value of the solid content of (A) (according to JISK5601-2-1: 1999) becomes 40 to 120 mg. KOH/g, preferably 60 to 120 mg. The polyhydric anhydride (d) is added as the calculated value of KOH/g. If the solid content acid value in this case is within this range, the alkaline aqueous solution developability of the photosensitive resin composition of the present invention will exhibit good developability. That is, the management range for good patterning and over-development is also wide, and no excessive acid anhydride remains.

In order to promote the reaction during the reaction, it is preferable to use a catalyst. The amount of the catalyst used is relative to the reactant (that is, the epoxy compound (a), the carboxylic acid compound (b), and the compound (c ) The total amount of the obtained reactive epoxy carboxylate compound (E), polyhydric acid anhydride (d), and optionally reactants such as solvents added) is 100 parts by mass, usually 0.1 to 10 parts by mass. The reaction temperature at this time is usually 60 to 150°C, and the reaction time is preferably 5 to 60 hours. Specific examples of catalysts that can be used include, for example, triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethyl iodide Ammonium ammonium, triphenylphosphine, triphenyl antimony hydride, methyl triphenyl antimony hydride, chromium octoate, zirconium octoate, etc.

The acid addition reaction of the present invention can be carried out without a solvent, or can be carried out by dilution with a solvent. Here, the solvent that can be used is not particularly limited as long as it is an inert solvent for the acid addition reaction set. In addition, when manufacturing using a solvent in the carboxylic acid esterification reaction as the previous step, it is also possible to directly supply the acid addition reaction as the subsequent step without removing the solvent, provided that the two reactions are inert. The usable solvent system is the same as the user that can be used in the esterification reaction of carboxylic acid.

The preferred amount of solvent should be adjusted appropriately according to the viscosity or use of the resin obtained, but it is preferably made into 90 to 30 parts by mass relative to 100 parts by mass of the solid content, more preferably it is made into 80 to 50 parts by mass Way.

In addition, it may be carried out in a single or mixed organic solvent such as a reactive compound (B) described later. In this case, when it is used in the form of a curable composition, it is preferably used directly as the composition.

In addition, the thermal polymerization inhibitor and the like are preferably the same as those listed in the carboxylic acid esterification reaction.

In this reaction, when proper sampling is performed, the point where the acid value of the reactant becomes the range of plus or minus 10% of the set acid value is taken as the end point.

The preferred molecular weight range of the reactive polycarboxylic acid compound (A) is a polystyrene-equivalent weight average molecular weight determined by GPC in the range of 500 to 50,000, more preferably 1,000 to 20,000.

The use ratio of the reactive polycarboxylic acid compound (A) in the resin composition is 5 to 70% by mass, preferably 10 to 65% by mass.

The reactive compound (B) that can be used in the present invention includes so-called free radical-reactive acrylates, cation-reactive other epoxy compounds, and vinyl-based compounds that sense both. Reactive oligomers.

Radical reactive acrylics include, for example, monofunctional (meth)acrylates, bifunctional (meth)acrylates, trifunctional or more (meth)acrylates, and urethanes (methyl ) Acrylate oligomer (urethane (meth) acrylate oligomer), polyester (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, etc.

Monofunctional (meth)acrylates include, for example: acryloylmorpholine; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, (meth)acrylic acid 4 -Hydroxy-containing (meth)acrylates such as hydroxybutyl ester; cyclohexane-1,4-dimethanol mono (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isocyano (meth)acrylate Aliphatic (meth)acrylates such as esters, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate; (methyl ) Phenoxyethyl acrylate, (poly)ethoxy phenyl (meth)acrylate, p-cumylphenoxyethyl (meth)acrylate, tribromophenyloxyethyl (meth)acrylate Ester, phenylthioethyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, phenylphenol (poly)ethoxy (meth)acrylate, phenyl Aromatic (meth)acrylates such as phenol epoxy (meth)acrylate.

Bifunctional (meth)acrylates include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di (Meth) acrylate, tricyclodecane dimethanol (meth) acrylate, bisphenol A (poly) ethoxy di (meth) acrylate, bisphenol A (poly) propoxy bis (methyl ) Acrylate, bisphenol F (poly)ethoxydi(meth)acrylate, ethylene glycol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylic acid Ester, di(meth)acrylate of ε-caprolactone adduct of hydroxytrimethylacetic acid neopentyl glycol (for example, KAYARAD HX-220, HX-620, etc. manufactured by Nippon Kayaku Co., Ltd.), etc. .

Multifunctional (meth)acrylates with more than 3 functions include di-trimethylolpropane tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethyloloctane Tri (meth) acrylate, trimethylol propane polyethoxy tri (meth) acrylate, trimethylol propane (poly) propoxy tri (meth) acrylate, trimethylol propane ( Poly)ethoxy (poly) propoxy tri (meth) acrylate and other methylols; neopentaerythritol tri (meth) acrylate, neopentaerythritol polyethoxy tetra (meth) acrylic acid Ester, neopentaerythritol (poly) propoxytetra (meth) acrylate, neopentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, di neopentaerythritol Neopentaerythritols such as penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate; see [(meth)acryloyloxyethyl] trimer isocyanate, caprolactone modification See [(meth)acryloyloxyethyl] trimer isocyanate, etc.; succinic acid modified neopentaerythritol triacrylate, succinic acid modified dipentaerythritol pentaacrylate.

(Poly)ester (meth)acrylate oligomers, for example, as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, polyethylene glycol , (Poly) propylene glycol and other glycols, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8 -Octanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, etc. Straight-chain or branched alkanediols, cyclohexane-1,4-dimethanol and other alicyclic alkanediols, bisphenol A (poly)ethoxydiol, or bisphenol A (poly)propoxy Diol compounds such as diols and the aforementioned dibasic acids (Poly)ester diol of the reactant of its acid anhydride, reactant of (meth)acrylic acid, etc.

Examples of urethane (meth)acrylate oligomers include diol compounds (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and 1, 4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 3- Methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, cyclohexane-1,4 -Dimethanol, polyethylene glycol, polypropylene glycol, bisphenol A polyethoxy glycol, bisphenol A poly propoxy glycol, etc.) or these diol compounds and dibasic acids or anhydrides (such as succinic acid, Polyester diol of the reactant of adipic acid, azelaic acid, dimer acid, isophthalic acid, terephthalic acid, phthalic acid or the like), and organic polyisocyanate (eg tetramethylene Diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate and other chain saturated hydrocarbon isocyanates; iso Phorone diisocyanate, norbornane diisocyanate, dicyclohexylmethane diisocyanate, methylene bis (4-cyclohexyl isocyanate), hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, hydrogenated toluene diisocyanate, etc. Saturated hydrocarbon isocyanate; 2,4-tolyl diisocyanate, 1,3-xylyl diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate, 6 -Aromatic polyisocyanates such as isopropyl-1,3-phenyl diisocyanate and 1,5-naphthalene diisocyanate) reacted and then added hydroxyl-containing (meth)acrylate, etc.

Epoxy (meth)acrylate oligomer system has epoxy Carboxylate compounds and (meth)acrylic acid carboxylate compounds. For example, phenol novolac type epoxy (meth)acrylate, cresol novolac type epoxy (meth)acrylate, para-hydroxyphenylmethane type epoxy (Meth) acrylate, dicyclopentadiene phenol epoxy (meth) acrylate, bisphenol A epoxy (meth) acrylate, bisphenol F epoxy (meth) acrylic Ester, biphenol epoxy (meth)acrylate, bisphenol A novolac epoxy (meth)acrylate, naphthalene-containing epoxy (meth)acrylate, glyoxal ring Oxygen (meth)acrylate, heterocyclic epoxy (meth)acrylate, etc.

Examples of vinyl compounds include vinyl ethers, styrenes, and other vinyl compounds. Examples of vinyl ethers include ethyl vinyl ether, propyl vinyl ether, hydroxyethyl vinyl ether, and ethylene glycol divinyl ether. Examples of styrenes include styrene, methylstyrene, and ethylstyrene. Examples of other vinyl compounds include triallyl trimer isocyanate, trimethallyl trimer isocyanate, and the like.

烷、雙(3,4-環氧基環己基)己二酸酯(Union Carbide公司製「CyracureUVR-6128」等)、雙(3,4-環氧基環己基甲基)己二酸酯、雙(3,4-環氧基環己基)醚、雙(3,4-環氧基環己基甲基)醚、雙(3,4-環氧基環己基)二乙基矽氧烷等。 In addition, the cation-reactive monomer is not particularly limited as long as it is a compound generally having an epoxy group. Examples include: glycidyl (meth)acrylate, methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl -3,4,-epoxycyclohexane carboxylate ("Cyracure UVR-6110" manufactured by Union Carbide, etc.), 3,4-epoxycyclohexylethyl-3,4-epoxycyclohexyl Alkyl carboxylate, vinyl cyclohexene dioxide ("ELR-4206" manufactured by Union Carbide, etc.), limonenedioxide ("Celloxide 3000" manufactured by Daicel Corporation, etc.), allyl dioxide Cyclohexene, 3,4,-epoxy-4-methylcyclohexyl-2-epoxypropane, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-ring Oxy)cyclohexane-methane

Alkane, bis(3,4-epoxycyclohexyl) adipate ("CyracureUVR-6128" manufactured by Union Carbide, etc.), bis(3,4-epoxycyclohexylmethyl) adipate, Bis(3,4-epoxycyclohexyl) ether, bis(3,4-epoxycyclohexylmethyl) ether, bis(3,4-epoxycyclohexyl) diethylsiloxane, etc.

Among these, the reactive compound (B) is preferably monofunctional, bifunctional, or trifunctional (methyl) from the viewpoint of good polymerizability and improvement of the strength of the resulting spacer, etc. Acrylic esters, etc.

The reactive compound (B) of this invention can be used individually or in mixture of 2 or more types. The use ratio of the reactive compound (B) in the composition is preferably 30 to 250 parts by mass, and more preferably 50 to 200 parts by mass with respect to 100 parts by mass of the reactive polycarboxylic acid compound (A). When the use amount of the reactive compound (B) is 30 to 250 parts by mass, the sensitivity of the composition, the heat resistance of the resulting cured product, etc., and the elastic properties become more favorable.

The photopolymerization initiator (C) of the present invention is capable of sensing the active energy rays to produce the polymerization of the reactive polycarboxylic acid compound (A) and the reactive polycarboxylic acid compound (A) other than the reactive polycarboxylic acid compound (A) The ingredients of the first active species. Examples of such a photopolymerization initiator (C) include an acetylphosphine compound, a benzoyloxime compound, an acetophenone compound, and a biimidazole compound.

Among them, the photopolymerization initiator is obtained by using an acylphosphine compound and a benzoyloxime compound together. Even if the heat curing step is not performed after the photohardening step by exposure, the reflectance, solder heat resistance, A cured product with excellent characteristics such as adhesion and coating hardness.

The acylphosphine-based photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator having an acylphosphine structure, and examples include: 2,4,6-trimethylbenzyl-diphenyl-oxide Phosphine, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, bis(2,6-dimethylbenzyl)-2,4,4-trimethyl-pentane Acylphosphine oxide compounds such as phosphine oxide, (2,4,6-trimethylbenzyl)ethoxyphenylphosphine oxide and the like.

The benzoyl oxime photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator having a benzoyl oxime structure, and examples include: 1,2-octanedione, 1-[4-(benzene Thio)-2-(O-benzyl oxime)], 2-propanedione-2-O-benzyl oxime, 1-phenyl-1,2-propanedione-2-O -Oxime ester compounds such as benzyl oxime.

The blending ratio of the acyl phosphine-based photopolymerization initiator and the benzoyl oxime-based photo polymerization initiator is not particularly limited, but for example, it is about 1 part by mass relative to the benzoyl oxime photo-polymerization initiator. The lower limit of the blending amount of the phosphine-based photopolymerization initiator is preferably 2 parts by mass from the viewpoint of preventing the reflectance of the cured product from decreasing, so that the internal hardening is sufficiently performed to further enhance the density From the viewpoint of the property, the lower limit is preferably 3 parts by mass, and from the viewpoint of reliably preventing the decrease in the reflectance of the cured product, the lower limit is particularly preferably 4 parts by mass. On the other hand, with respect to 1 part by mass of the benzoyl oxime-based photopolymerization initiator, the upper limit of the blending amount of the amide phosphine-based photopolymerization initiator reliably improves solder heat resistance and adhesion From the viewpoint of the above, the upper limit is preferably 100 parts by mass. From the viewpoint of reliably preventing the decrease in the hardness of the coating film, the upper limit is more preferably 50 parts by mass, so that the solder heat resistance and adhesion From a good balance point of view, the upper limit It is preferably 10 parts by mass.

That is, the blending ratio of the acyl phosphine-based photopolymerization initiator to the benzoyl oxime photo-polymerization initiator is 1 part by mass relative to the benzoyl oxime-based photo polymerization initiator, and the acetyl phosphine-based photopolymerization initiator The photopolymerization initiator is usually about 2 to 100 parts by mass, preferably about 3 to 50 parts by mass, and particularly preferably about 4 to 10 parts by mass.

The total amount of the acylphosphine-based photopolymerization initiator and the benzoyloxime-based photopolymerization initiator is not particularly limited, but for example, it is true with respect to 100 parts by mass of the reactive polycarboxylic acid compound (A) From the viewpoint of imparting photocurability and improving the mechanical strength of the cured product, the lower limit is preferably 1 part by mass, and from the viewpoint of improving heat resistance, the lower limit is particularly preferably 2 parts by mass. On the other hand, from the viewpoint of suppressing the discoloration caused by the oxidative decomposition of the photopolymerization initiator to reduce the reflectance, the upper limit is preferably 30 parts by mass, from the viewpoint of adhesion to the substrate It can be seen that the upper limit value is particularly preferably 20 parts by mass.

That is, the total amount of the compounding amount of the acetylphosphine-based photopolymerization initiator and the benzoyloxime-based photopolymerization initiator is preferably 100 parts by mass relative to the reactive polycarboxylic acid compound (A), and is preferably 1 to 30 parts by mass, more preferably about 2 to 20 parts by mass.

Titanium oxide (D) is prepared by whitening hardened materials such as coating films, and examples thereof include anatase-type titanium oxide and rutile-type titanium oxide having a rutile crystal structure. Among these, from the viewpoint of whiteness, rutile titanium oxide is preferred. Examples of the rutile titanium oxide system include "TR-600" manufactured by Fuji Titanium Industry Co., Ltd., "TR-700", "TR-750", "TR-840"; "R-550", "R-580", "R-630", "R-820", "CR" manufactured by Ishihara Industries Co., Ltd. -50", "CR-60", "CR-80", "CR-90", "CR-93"; "KR-270", "KR-310", "KR-380" manufactured by Titan Industries Co., Ltd. "Wait. These can be used individually or in mixture of 2 or more types.

The formulation amount of titanium oxide (D) is not particularly limited, but it is preferably 30 to 200 parts by mass from the viewpoint of the balance between the whiteness and strength of the hardened product relative to 100 parts by mass of the reactive polycarboxylic acid compound (A). About 50 parts to 150 parts by mass.

In addition to the above-mentioned components, the white active energy ray-curable resin composition of the present invention may contain various additional components as needed, such as an antifoaming agent, a dispersing agent, a solvent, an extender pigment, and the like.

Known antifoaming agents can be used, and examples thereof include polysiloxane-based, hydrocarbon-based, and acrylic-based ones. Examples of the dispersant include coupling agents such as silane-based, titanate-based, and alumina-based.

The solvent system is used to adjust the viscosity or dryness of the white active energy ray-curable resin composition, and examples include ketones such as methyl ethyl ketone and cyclohexane; aromatic hydrocarbons such as toluene and xylene; methanol, Alcohols such as isopropanol and cyclohexanol; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; petroleum solvents such as petroleum ether and naphtha; cellosolve and butylcellosolve Etc. carbitol, carbitol, butyl carbitol and other carbitols; ethyl acetate, butyl acetate, cylosulfoacetate, butyl cylosulfoacetate, carbitol Acetates such as alcohol acetate and butyl carbitol acetate. These can be used individually or in mixture of 2 or more types.

The extender pigment is used to assist in enhancing the mechanical strength of the cured product (for example, the solder mask after coating), and examples thereof include silicon oxide, barium sulfate, aluminum oxide, aluminum hydroxide, talc, and mica.

In addition, in the present invention, titanium oxide is used to color the active energy ray-curable resin composition to white, but depending on the application, blue colorants and yellow colorants may be appropriately added within the range that does not affect the effects of the present invention. , Black colorants and other colorants. Specific examples of coloring agents other than white include organic pigments such as phthalocyanine series such as phthalocyanine green and phthalocyanine blue, anthraquinone series, and azo series, and inorganic pigments such as carbon black.

The manufacturing method of the active energy ray-curable resin composition of the present invention described above is not limited to a specific method, but, for example, the above-mentioned components can be prepared at a predetermined ratio and then used at room temperature using a three-roll mill, ball mill, sand mixing It is manufactured by mixing means such as a machine, or stirring means such as a super mixer or a planetary mixer. In addition, before the aforementioned kneading or mixing, preliminary kneading or preliminary mixing may be performed as necessary.

Next, the method of using the white active energy ray-curable resin composition of the present invention described above will be described. Here, the case where the white active energy ray-curable resin composition of the present invention is applied to a circuit board as a solder resist film will be described as an example.

The white active energy ray-curable resin composition of the present invention obtained as described above is used for screen printing, spray coater, bar coater, applicator, blade coater , Air knife coater (knife coater), roll coater, gravure coater and other well-known coating methods, for example, coated with copper foil formed after etching The printed wiring board of the road pattern has a desired thickness. In addition, after coating, if necessary, in order to evaporate the solvent in the white active energy ray-curable resin composition, preliminary drying at a temperature of about 60 to 80°C for about 15 to 60 minutes may be performed to form a non-sticky Coated film. A negative film having a light-transmitting pattern other than the circuit pattern land is adhered to the white active energy ray-curable resin composition applied by a known coating method, and irradiated from above The active energy rays (for example, ultraviolet rays) photoharden the coating film. Next, the non-exposed area corresponding to the aforementioned land is removed with a weak alkaline aqueous solution to develop the coating film, and the target solder resist film can be formed on the printed wiring board. Among the above-mentioned development methods, a spray method, a bath method, and the like are used, and the weakly alkaline aqueous solution used is not particularly limited, and examples thereof include 0.5 to 5% sodium carbonate aqueous solution. In addition, when the development coating film is not required, the white active energy ray-curable resin composition can be photocured without using a negative film.

On the circuit board coated with the solder mask obtained in this way, an electronic circuit unit is formed by soldering electronic parts by a jet welding method, a reflow soldering method, or the like.

The cured product and cured film of the light-cured white active energy ray curable resin composition, and the circuit board or printed wiring board having the cured product or the cured film are also included in the present invention.

(Example)

Hereinafter, the present invention will be described in more detail with examples, but the present invention is not limited to these examples. In addition, in the examples, as long as there is no special statement, "parts" means mass parts, and "%" means mass %.

The softening point, epoxy equivalent, and acid value are measured under the following conditions.

1) Epoxy equivalent: measured in accordance with JISK7236:2001.

2) Softening point: measured according to the method of JISK7234:1986.

3) Acid value: measured in accordance with JISK0070:1992.

Examples 1-1 to 1-3

[Preparation of reactive polycarboxylic acid compound (A)]

Add the amount stated in Table 1 as the epoxy resin (a) NC-6300H (manufactured by Nippon Kayaku; general formula (1), n=0 (64%), n=1 (23%), n=2 or more (13%); the epoxy equivalent of 230g/eq.), the amount of acrylic acid (AA, Mw=72) as the compound (b) described in Table 1 and the amount of the compound (c) as the compound described in Table 1 Hydroxymethyl propionic acid (DMPA for short, Mw=134). 3 g of triphenylphosphine as a catalyst and propylene glycol monomethyl ether monoacetate as a solvent were added so that the solid content became 80% by mass of the reaction liquid, and reacted at 100° C. for 24 hours to obtain reactivity Epoxy carboxylate compound (E) solution. The solid acid value (AV: mg.KOH/g) 5 or less was taken as the end point of the reaction, and the next reaction was started. The acid value is measured in the reaction solution, and converted to the acid value in terms of solid content.

Next, to the solution of the reactive epoxy carboxylate compound (E), tetrahydrophthalic anhydride (abbreviated as abbreviated as polybasic acid anhydride (d)) was added in an amount described in Table 1 so that the solid content became 65% by mass. THPA), and propylene glycol monomethyl ether monoacetate as a solvent, and heated to 100°C, and then subjected to an acid addition reaction to obtain a reactive polycarboxylic acid compound (A) solution. The acid value of solid content (AV: mg.KOH/g) is shown in Table 1.

Comparative examples 1-1, 1-2

[Preparation of reactive polycarboxylic acid compound for comparison]

Except that the epoxy resin was changed from the epoxy resin (a) of Examples 1-1 to 1-3 to the cresol novolac type epoxy resin EOCN-103S (manufactured by Nippon Kayaku, epoxy equivalent Except for 200 g/eq.), the rest was carried out in the same manner as in Examples 1-1 to 1-3 to obtain a carboxylate compound solution.

Next, it carried out similarly to Examples 1-1 to 1-3, and obtained the reactive polycarboxylic acid compound solution for comparison. The solid content acid value (AV: mgKOH/g) is shown in Table 1.

Comparative example 1-3

[Preparation of a reactive polycarboxylic acid compound that does not have an aromatic ring for comparison]

In a 2 liter separable flask equipped with a stirrer, thermometer, reflux cooler, dropping funnel and nitrogen introduction tube, add 900 g of diethylene glycol dimethyl ether as a solvent and peroxide as a polymerization initiator- After tert-butyl 2-ethylhexanoate (Perbutyl®O manufactured by Nippon Oil & Fats Co., Ltd.) 21.4 g, it was heated to 90°C. After heating, 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and 109.8 g of lactone-modified 2-hydroxyethyl methacrylate (Placcel FM1 manufactured by Daicel Co., Ltd.) and polymerization start 21.4g of bis(4-tert-butylcyclohexyl) peroxydicarbonate (Peroyl TCP manufactured by Nippon Oil & Fats Co., Ltd.) was added dropwise together for 3 hours, followed by aging for 6 hours, thereby obtaining a carboxyl group-containing Copolymer resin. In addition, the reaction is carried out under a nitrogen atmosphere.

Next, to the obtained carboxyl group-containing copolymer resin, 3,4-epoxycyclohexyl methacrylate (made by Daicel Corporation) was added Cyclomer A200) 363.9g, 3.6g of dimethylbenzylamine as a ring-opening catalyst, and 1.80g of hydroquinone monomethyl ether as a polymerization inhibitor, heated to 100°C, and stirred Ring-opening addition reaction of epoxy groups. After 16 hours, the acid value of the solid content was 108.9 mg. KOH/g, a weight average molecular weight of 25,000, containing 65% by mass (solid content) of a carboxyl group-containing resin having no aromatic ring.

<Preparation of the composition of the present invention>

Each component shown in the following Table 2 was prepared according to the formulation ratio shown in the following Table 2, mixed and dispersed using a three-roll mill at room temperature, and Examples 2-1 to 2-3 and Comparative Example 2-1 were prepared White active energy ray-curable resin composition used up to 2-3.

The details of each component used in Examples and Comparative Examples are shown.

<Reactive compound (B)>

B-1: Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate Compound (KAYARAD DPHA, manufactured by Nippon Kayaku)

<Photopolymerization initiator (C)>

C-1: Acylphosphine series photopolymerization initiator

‧Bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide (IRGACURE 819, manufactured by BASF)

C-2: Benzoyl oxime photopolymerization initiator

‧1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyl oxime)] (IRGACURE OXE 01, manufactured by BASF)

<Titanium oxide (D)>

D-1: Rutile titanium oxide (CR-80, manufactured by Ishihara Industries Co., Ltd.)

<Preparation of test piece>

A printed wiring board with a circuit pattern formed on a copper-clad laminate (FR-4, thickness 1.6 mm, conductor thickness 35 μm) will be polished with a polishing wheel (grinding wheel) (corresponding to English: mopping or buffing or polishing) for surface treatment. Next, the compositions of the present invention of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3 were applied to the printed wiring board by the screen printing method, respectively. Then, the prepared printed wiring board was dried in a hot-air circulation drying oven at 80°C for 30 minutes. For the coating film of the printed wiring board after drying, use an exposure device (model HMW-680GW manufactured by ORC Manufacturing Co., Ltd.) to expose 2000 mJ/cm ² of ultraviolet rays (wavelength 300 to 400 nm) (photocuring step) to the printed wiring A cured coating film of the composition of the present invention was formed on the board to prepare a test piece. The thickness of the cured coating film is 15 to 20 μm.

<evaluation>

The following evaluation was performed about the composition of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3, and the test piece formed from the coating film. The evaluation results are also shown in Table 3.

(1) Reflectivity

Using a spectrophotometer U-3310H (manufactured by Hitachi, Ltd.: φ 60 mm integrating sphere), the reflectance at 450 nm of the test piece coated with the cured coating film was measured.

(2) Light resistance

The obtained test piece was irradiated with Super UV (90mW) light for 24 hours to accelerate the deterioration, and then a spectrophotometer U-3310H (manufactured by Hitachi) was used. Co., Ltd.: φ 60mm integrating sphere), to measure the color change. ΔE*ab represents the change in color. The smaller the value, the smaller the color change.

(3) Solder heat resistance

After immersing the cured coating film of the test piece in the solder bath at 260°C for 10 seconds according to the test method of JIS C-6481, the peeling test using cellophane tape was set as 1 cycle, The state of the coating film after 1 to 2 cycles of the repetitive operation was visually observed and evaluated according to the following criteria.

○: After 2 cycles of repeated operations, no change in the coating film was confirmed.

△: It was confirmed that the coating film changed after 2 cycles of repeated operations.

×: It was confirmed that the coating film peeled off after one cycle of the repeated operation.

(4) Adhesion

In accordance with JIS K-5600-5-6, 100 squares (10×10) of 1 mm squares were set on the test piece, and a peeling test using celluloid tape was carried out, and the peeling state of the squares was visually observed and calculated as 100 The number of squares among the squares that are not peeled off from the substrate.

(5) Coating film hardness

According to the test method of JIS K-5600-5-4, grind the tip of the core into a flat 3B to 9H pencil to press the hardened coating on the copper foil of the test piece at an angle of 45°, and record that no coating has occurred The hardness of the peeling pencil.

From the above results, it can be seen that the white active energy ray-curable compositions containing the reactive polycarboxylic acid compound (A) of the present invention of Examples 2-1 to 2-3 are compared to Comparative Examples 2-1 to 2 The composition of -3 has good reflectivity, light resistance and solder heat resistance, and has excellent adhesion and coating film hardness. In addition, it can be observed that Example 2-1 and Example 2-2 using DMPA (compound (c)) in the preparation of the reactive polycarboxylic acid compound (A) are compared to the unused compound (c) Example 2-3, which shows more excellent adhesion.

(Industry availability)

The white active energy ray-curable resin composition of the present invention can obtain a cured product excellent in reflectivity, solder heat resistance, adhesion, and coating film hardness even without performing a thermal curing step after the light curing step. Printed wiring boards have high utilization value in the fields of solder masks and cover films.

Claims (6)

A white active energy ray-curable resin composition comprising: a reactive polycarboxylic acid compound (A), a reactive compound (B) other than the reactive polycarboxylic acid compound (A), and a photopolymerization initiator (C) And titanium oxide (D), wherein the reactive polycarboxylic acid compound (A) is obtained by reacting the reactant (E) with the polybasic acid anhydride (d), and the reactant (E) is represented by the general formula (1) The epoxy resin (a) shown and the compound having more than one polymerizable ethylenically unsaturated group and more than one carboxyl group in one molecule (b) and at least two hydroxyl groups in one molecule if necessary Reactant with more than one carboxyl compound (c);

In the formula, n represents a positive number from 0 to 2; the reactive compound (B) is a radical-reactive acrylate, a cation-reactive other epoxy compound, or a vinyl compound that senses both. The white active energy ray hardening type tree as described in item 1 of the patent application scope Fat composition, wherein the reactive polycarboxylic acid compound (A) is obtained by reacting the reactant (E) with the polybasic acid anhydride (d), and the reactant (E) is an epoxy compound represented by the general formula (1) Resin (a) and compound having more than one polymerizable ethylenic unsaturated group and more than one carboxyl group in one molecule (b) and compound having at least two more hydroxyl groups and more than one carboxyl group in one molecule (c) reactants. The white active energy ray-curable resin composition as described in item 1 or 2 of the patent application scope, wherein the photopolymerization initiator (C) is an acetylphosphine-based photopolymerization initiator and a benzoyloxime-based photopolymerization The polymerization initiator has a compounding ratio of 2 to 100 parts by mass relative to 1 part by mass of the benzoyl oxime-based photopolymerization initiator. The white active energy ray-curable resin composition as described in item 3 of the patent application range, wherein the amide phosphine-based photopolymerization initiator is selected from 2,4,6-trimethylbenzyl-diphenyl -Phosphine oxide, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, bis(2,6-dimethylbenzyl)-2,4,4-trimethyl More than one of the group consisting of phenyl-pentylphosphine oxide and (2,4,6-trimethylbenzyl)ethoxyphenylphosphine oxide, benzoyl oxime series photopolymerization initiator system Selected from 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyl oxime)], 2-propanedione-2-O-benzoyl One or more of the group consisting of oxime and 1-phenyl-1,2-propanedione-2-O-benzoyl oxime. A hardened product, which is a hardened product of the white active energy ray-curable resin composition described in item 1 of the patent scope. A printed wiring board having a cured film of a white active energy ray-curable resin composition as described in item 1 of the patent scope.