KR102480646B1 - Active energy ray curable resin composition with white color and cured product thereof, and printed wiring board - Google Patents

Abstract

(Problem) To provide a white active energy ray-curable resin composition capable of forming a cured product having basic properties such as solder heat resistance, adhesion, and coating film hardness without further performing a thermal curing step after the photocuring step. .
(Solution) A polybasic acid anhydride is added to the reaction product (E) of the epoxy resin (a) represented by the general formula (1), acrylic acid (b), and the compound (c) having at least two hydroxyl groups and one or more carboxyl groups in one molecule. A white active energy ray-curable resin composition containing a reactive polycarboxylic acid compound (A) obtained by reacting (d), a reactive compound (B) other than (A), a photopolymerization initiator (C), and titanium oxide (D).

Description

White active energy ray-curable resin composition, cured product thereof, and printed wiring board

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 coated article such as a printed wiring board coated with a cured product obtained by curing the same.

A printed wiring board is generally used to form a pattern of a conductor circuit on a board and to mount electronic components on solder lands of the circuit pattern by soldering. Circuit portions other than the solder lands are covered with a solder resist film as a permanent protective film. This prevents solder from adhering to unnecessary parts when soldering electronic components on a printed wiring board, and prevents circuit conductors from being directly exposed to air and corroded by oxidation or humidity.

Conventionally, in order to form a solder resist film provided with basic characteristics such as solder heat resistance and coating film hardness on a printed wiring board, a photocuring step and a thermosetting step have been required as in Patent Document 1. First, after apply|coating an active energy ray-curable resin composition to a printed wiring board, pre-drying is performed at the temperature of about 60-100 degreeC as needed, and a coating film is formed. Next, on the active energy ray-curable resin composition, a negative film having a light-transmitting pattern except for the lands of the circuit pattern is brought into close contact, and photocured by irradiation with active energy rays (eg, ultraviolet rays). In addition, the non-exposed area is removed with a diluted 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 to form a cured coating film of the active energy ray-curable resin composition on the printed wiring board.

However, in such a conventional solder resist film formation method, since a photocuring process and a thermosetting process are performed, there existed a problem that productivity of a film formed product did not improve. In addition, in forming a solder resist film on a substrate having low heat resistance, there is a problem in that the heat of the thermal curing process causes deterioration in quality of the substrate, such as deformation of the substrate.

Patent Document 2 discloses that a resin composition containing an unsaturated group-containing polycarboxylic acid is suitable for a solder resist, but there is no description of a white active energy ray-curable resin composition in which titanium oxide or the like is dispersed. .

Japanese Unexamined Patent Publication No. 2008-257044 Japanese Patent Publication No. 2704661

The present invention has been made in view of the above circumstances, and an object of the present invention is a cured product having basic properties such as solder heat resistance, adhesion, coating film hardness, and the like, even without performing a thermal curing step after the photocuring step. It is to provide a white active energy ray-curable resin composition capable of forming.

As a result of earnestly examining in order to solve the said subject, the present inventors discovered that the resin composition which has a specific compound and composition solves the said subject, and reached this invention.

That is, the present invention,

(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), a photopolymerization initiator (C), and titanium oxide (D), , The reactive polycarboxylic acid compound (A) is an epoxy resin represented by the general formula (1) (a) and a compound (b) having at least one polymerizable ethylenically unsaturated group and at least one carboxy group in one molecule, and optionally The reactive polycarboxylic acid compound (A) obtained by further reacting a polybasic acid anhydride (d) with the reactant (E) of the compound (c) having at least two or more hydroxyl groups and one or more carboxy groups in one molecule. It relates to an energy ray curable resin composition:

(In the formula, n represents an integer of 0 to 2).

(2) In the present invention, the reactive polycarboxylic acid compound (A) is a compound having at least one polymerizable ethylenically unsaturated group and at least one carboxy group in one molecule with the epoxy resin (a) represented by the general formula (1) Reactive polycarboxylic acid compound (A) obtained by further reacting a polybasic acid anhydride (d) with the reactant (E) of (b) and the compound (c) having at least two or more hydroxyl groups and one or more carboxy groups in one molecule. , It is related with the white active energy ray-curable resin composition as described in said (1).

(3) Further, in the present invention, the photopolymerization initiator (C) is an acylphosphine-based photopolymerization initiator and a benzoyloxime-based photopolymerization initiator, and the blending ratio thereof is 2 parts by mass of the acylphosphine-based photopolymerization initiator with respect to 1 part by mass of the benzoyloxime-based photopolymerization initiator. It is related with the white active energy ray-curable resin composition as described in said (1) or (2) which is -100 mass parts.

(4) Further, in the present invention, the photopolymerization initiator (C) is an acylphosphine-based photopolymerization initiator and a benzoyloxime-based photopolymerization initiator, and the blending ratio thereof is 3 parts by mass of the acylphosphine-based photopolymerization initiator with respect to 1 part by mass of the benzoyloxime-based photopolymerization initiator. It is related with the white active energy ray-curable resin composition as described in said (1) or (2) which is -50 mass parts.

(5) Further, in the present invention, the photopolymerization initiator (C) is an acylphosphine-based photopolymerization initiator and a benzoyloxime-based photopolymerization initiator, and the blending ratio thereof is 4 parts by mass of the acylphosphine-based photopolymerization initiator with respect to 1 part by mass of the benzoyloxime-based photopolymerization initiator. It is related with the white active energy ray-curable resin composition as described in said (1) or (2) which is -10 mass parts.

(6) In addition, the present invention, the acylphosphine-based photopolymerization initiator is 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2 ,6-dimethylbenzoyl) -2,4,4-trimethyl-pentylphosphine oxide and (2,4,6-trimethylbenzoyl) ethoxyphenyl phosphine oxide, and at least one selected from the group consisting of benzoyl oxime The photopolymerization initiator is 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzoyloxime)], 2-propanedione-2-O-benzoyloxime, 1-phenyl-1,2- It is related with the white active energy ray-curable resin composition as described in said (3)-(5) which is 1 or more types selected from the group which consists of propanedione 2-O-benzoyl oxime.

(7) The present invention also relates to a cured product of the white active energy ray-curable resin composition according to any one of (1) to (6) above.

(8) The present invention also relates to a printed wiring board having a cured coating of the white active energy ray-curable resin composition according to any one of (1) to (6) above.

According to the embodiment of the present invention, by blending the reactive polycarboxylic acid compound (A), the reflectance and solder heat resistance can be improved without performing the thermal curing step after the photocuring step by exposure, that is, by exposure treatment with active energy rays. , a cured product having excellent properties such as adhesion and film hardness can be obtained. In addition, in the embodiment of the present invention, since a cured product excellent in the various characteristics described above can be obtained without performing a thermal curing step after the photocuring step, the production efficiency of a product, for example, a printed wiring board having a cured film is improved. improve

(Mode for implementing the invention)

Hereinafter, the present invention will be described in detail.

The reactive polycarboxylic acid compound (A) in the present invention is an epoxy resin represented by Formula (1) (a) and a compound (b) having at least one polymerizable ethylenically unsaturated group and at least one carboxy group in one molecule. And it is obtained by making a polybasic acid anhydride (d) react with the reaction material (E) of the compound (c) which has at least 2 or more hydroxyl group and 1 or more carboxy group in 1 molecule as needed.

That is, the reactive polycarboxylic acid compound (A) in the present invention is obtained by reacting the polybasic acid anhydride (d) with the reaction product (E) of the epoxy resin (a) and the compound (b), or with the epoxy resin (a) It is obtained by making a polybasic acid anhydride (d) react with the reactant (E) of compound (b) and compound (c).

In the present invention, the characteristics of the present invention are exhibited by introducing an ethylenically unsaturated group and a hydroxyl group into the molecular chain through an epoxy carboxylate reaction.

The epoxy resin (a) represented by the general formula (1) in the present invention is (4(4(1,1-bis(p-hydroxyphenyl)-ethyl)α,α-dimethylbenzyl)phenol) (hereinafter , It is obtained by reacting a phenolic compound (PA1)) with epihalohydrin. This epoxy resin is represented by the following representative structure:

(In the formula, n represents an integer of 0 to 2).

This epoxy resin is generally available as TECMOREVG3101L (manufactured by Printec), NC-6300C (manufactured by Nippon Gayaku), NC-6300H (manufactured by Nippon Gayaku), etc., but also by the following manufacturing method, the general formula (1) The compound can be obtained by manufacturing.

Moreover, as for the epoxy resin (a) used in this invention, it is more preferable that it is solid at normal 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 usually used, but one having a softening point of 60 to 100°C or a melting point of 60 to 190°C is preferred. In addition, epoxy equivalents of 130 to 500 g/eq. can usually be used in the present invention, but are preferably 150 to 400 g/eq., and more preferably 170 to 300 g/eq. If the epoxy equivalent is too small, it tends to be hard and brittle, and if the epoxy equivalent is too large, the hardness is difficult to come out and the glass transition point may be low.

Examples of the epihalohydrin used in the reaction between the phenolic compound (PA1) and epihalohydrin include epichlorohydrin, α-methylepichlorohydrin, γ-methylepichlorohydrin, and epibromohydrin. These etc. are mentioned, In this invention, industrially easily available epichlorohydrin is preferable. The amount of epihalohydrin used is usually 2 to 15 moles, preferably 4 to 10 moles, per mole of the hydroxyl group of the phenolic compound (PA1). When the remaining excess epihalohydrin is used, not only productivity is bad, but also the softening point of the epoxy resin to be produced is lowered, which may not have a good effect on tackiness or the like when used as a prepreg. In addition, when the amount of epihalohydrin is less than 2 mol, the value of n may become large and gelation may easily occur during production.

In the epoxidation reaction, it is preferable to use an alkali metal hydroxide. Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. In addition, an alkali metal hydroxide may be used as a solid substance or as an aqueous solution thereof. For example, when an alkali metal hydroxide is used as an aqueous solution, an aqueous solution of the alkali metal hydroxide is continuously added into the reaction system, while water and epihalohydrin are continuously distilled off under reduced pressure or normal pressure, and The epoxidation reaction can be performed by a method in which water is removed by liquid separation and epihalohydrin is continuously returned to the reaction system. Moreover, when using a solid, it is preferable to use a flake-shaped thing from problems, such as the ease of handling and solubility. The amount of the alkali metal hydroxide used is usually 0.90 to 1.5 moles, preferably 1.01 to 1.25 moles, more preferably 1.01 to 1.15 moles per mole of the hydroxyl group of the phenolic compound (PA1).

In the epoxidation reaction, to promote the reaction, quaternary ammonium salts such as tetramethylammonium chloride, tetramethylammonium bromide, and trimethylbenzylammonium chloride, tetramethylphosphonium chloride, tetramethylphosphonium bromide, and trimethylbenzylphosphonium chloride , A quaternary phosphonium salt such as triphenylbenzylphosphonium chloride or triphenylethyl bromide may be added as a catalyst. The amount of these quaternary salts used is usually 0.1 to 15 g, preferably 0.2 to 10 g, per mole of the hydroxyl group of the phenolic compound (PA1).

In the epoxidation reaction, alcohols such as methanol, ethanol and isopropyl alcohol, ethers such as tetrahydrofuran and dioxane, aprotic polar solvents such as dimethyl sulfone, dimethyl sulfoxide and dimethyl imidazolidinone, etc. It is preferable to carry out the reaction by adding , and in the present invention, the use of alcohols and/or ethers is particularly preferable in view of their optical properties.

When the above alcohols or ethers are used, their amount is usually 2 to 50% by mass, preferably 4 to 20% by mass, based on the amount of epihalohydrin. On the other hand, when the aprotic polar solvent is used, the amount used is usually 5 to 100% by mass, preferably 10 to 80% by mass, based on the amount of epihalohydrin.

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. This reaction may be carried out under normal pressure or reduced pressure, and may be reacted under reduced pressure conditions under conditions of azeotropic dehydration of water and epihalohydrin. The reaction product of these epoxidation reactions can be purified by removing epihalohydrin, a solvent, or the like after washing with water or without washing with water under heating and reduced pressure. Further, in order to obtain an epoxy resin with fewer hydrolysable halogens, the recovered reactants are dissolved in a solvent such as toluene or methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to form part ( It is preferable to carry out a ring closure reaction of the sub-product to ensure ring closure of halohydrin as a by-product.

In this case, the amount of alkali metal hydroxide used is usually 0.01 to 0.3 moles, preferably 0.05 to 0.2 moles, per mole of the hydroxyl group of the phenolic compound (PA1) used for epoxidation. In addition, the reaction temperature is usually 50 to 120°C, and the reaction time is usually 0.5 to 2 hours.

In the above epoxidation reaction, after completion of the reaction, the formed salt is removed by filtration, washing with water, etc., and further, the solvent is distilled off under reduced pressure by heating, so that an epoxy resin usable in the present invention can be obtained. Epoxy resins obtained in this way include those to which an epoxy resin was partially added with a solvent or water, and those in which halogens remained without ring closure at all.

The thus obtained epoxy resin (a), which is a reaction product of the phenolic compound (PA1) and epihalohydrin, is excellent in productivity and handleability, and satisfies any of the following conditions for imparting high mechanical strength to a cured product: It is desirable to do

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

2. In gel permeation chromatography, 30 area% or less of two phenol compounds (PA1) connected by epihalohydrin, 20 area% or less of inert connection, more preferably 25 Area% or less, inert connection is 15 area% or less. As the remainder, the monomer of the epoxy resin (a) corresponds.

The compound (b) having at least one polymerizable ethylenically unsaturated group and at least one carboxy group in one molecule in the present invention is reacted to impart reactivity to active energy rays. The ethylenically unsaturated group and the carboxy group are not particularly limited as long as one or more are present in each molecule. Examples of these include monocarboxylic acid compounds and polycarboxylic acid compounds.

Examples of monocarboxylic acid compounds having one carboxyl group per molecule include (meth)acrylic acids, crotonic acids, α-cyanocinnamic acids, cinnamic acids, or monoglycidyl compounds containing saturated or unsaturated dibasic acids and unsaturated groups. reactants. In the above, as (meth)acrylic acid, for example, (meth)acrylic acid, β-styryl acrylic acid, β-furfuryl acrylic acid, (meth)acrylic acid dimer, saturated or unsaturated dibasic acid anhydride and one molecule in one molecule Half esters which are an equimolar reaction product of a (meth)acrylate derivative having a hydroxyl group, and half esters which are an equimolar reaction product of a saturated or unsaturated dibasic acid and monoglycidyl (meth)acrylate derivatives.

In addition, as the polycarboxylic acid compound having two or more carboxyl groups in one molecule, half esters that are equimolar reactants with (meth)acrylate derivatives having a plurality of hydroxyl groups in one molecule, glycols having a saturated or unsaturated dibasic acid and a plurality of epoxy groups and half esters which are equimolar reactants of cydyl (meth)acrylate derivatives.

Among these, (meth)acrylic acid, the reaction product of (meth)acrylic acid and epsilon-caprolactone, or cinnamic acid are mentioned most preferably from the viewpoint of sensitivity when it is set as an active energy ray-curable resin composition. As a compound (b), what does not have a hydroxyl group in a compound is preferable.

The compound (c) having at least two or more hydroxyl groups and one or more carboxy groups in one molecule, which is used as necessary in the present invention, is reacted for the purpose of introducing a hydroxyl group into a carboxylate compound.

Specific examples of the compound (c) having at least two or more hydroxyl groups and one or more carboxy groups in one molecule in the present invention include, for example, dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolacetic acid, dimethylolbutyric acid, and dimethylol. and polyhydroxy-containing monocarboxylic acids such as valeric acid and dimethylolcaproic acid. As a particularly preferable thing, dimethylol propionic acid etc. are mentioned, for example.

Among these, considering the stability of the reaction between the epoxy resin (a), the compound (b) and the compound (c), it is preferable that the compound (b) and the compound (c) are monocarboxylic acids, and monocarboxylic acids and polycarboxylic acids. Even when an acid is used in combination, it is preferable that the value represented by total molar amount of monocarboxylic acid/total molar amount of polycarboxylic acid is 15 or more.

The addition ratio of the epoxy resin (a) and the compound (b) in this reaction and the total amount of carboxylic acids of the compound (c) used as needed should be appropriately changed depending on the use. That is, when all the epoxy groups are carboxylated, since no unreacted epoxy groups remain, the storage stability as a reactive epoxy carboxylate compound is high. In this case, only the reactivity due to the introduced double bond is used.

On the other hand, by deliberately reducing the amount of the carboxylic acid compound to leave unreacted residual epoxy groups, the reactivity due to the introduced unsaturated bond and the reaction due to the remaining epoxy groups, for example, a polymerization reaction or a thermal polymerization reaction using a photocationic catalyst It is also possible to use a combination of However, in this case, attention must be paid to preservation of the reactive epoxy carboxylate compound (E) and examination of manufacturing conditions.

In the case of producing a reactive epoxy carboxylate compound (E) in which no epoxy group remains, the total amount of the compound (b) and the compound (c) used as necessary is 90 to 120 equivalents relative to 1 equivalent of the epoxy resin (a). % is preferred. If it is this range, manufacture under relatively stable conditions is possible. If the total amount of the compound (b) and the compound (c) used as needed is larger than this, it is not preferable because excess compounds (b) and compounds (c) remain.

In addition, when leaving an epoxy group intentionally, it is preferable that the total amount of the compound (b) and the compound (c) used as needed is 20 to 90 equivalent% with respect to 1 equivalent of the said epoxy resin (a). When it deviates from this range, further reaction by an epoxy group does not fully advance. In this case, sufficient attention is required for gelation during the reaction and stability over time of the reactive epoxy carboxylate compound (E).

In the case of using the compound (b) and the compound (c), the ratio of compound (b):compound (c) is 95:5 to 5:95, furthermore 95: The range of 5-40:60 is preferable. Within this range, the sensitivity to active energy rays is good, and sufficient hydroxyl groups can be introduced in order to make the polybasic acid anhydride (d) react with the reactive epoxy carboxylate compound (E).

The carboxylation reaction can be carried out without a solvent or diluted with a solvent. As a solvent that can be used here, there will be no particular limitation as long as it is an inert solvent for the carboxylate reaction.

The amount of the solvent to be used is preferably adjusted appropriately depending on the viscosity and use of the resin to be obtained, but is preferably 90 to 30 parts by mass, more preferably 80 to 50 parts by mass, based on 100 parts by mass of the solid content.

Specifically, for example, aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, and tetramethylbenzene, aliphatic hydrocarbon solvents such as hexane, octane, and decane, and mixtures thereof such as petroleum ether, white gasoline, and solvent naphtha etc., an ester solvent, an ether solvent, a ketone solvent, etc. are mentioned.

Examples of the ester solvent include alkyl acetates such as ethyl acetate, propyl acetate, and butyl acetate, cyclic esters such as γ-butyrolactone, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether monoacetate, and diethylene glycol mono. Mono or polyalkylene glycol monoalkyl ether mono such as ethyl ether monoacetate, triethylene glycol monoethyl ether monoacetate, diethylene glycol monobutyl ether monoacetate, propylene glycol monomethyl ether acetate, butylene glycol monomethyl ether acetate and polycarboxylic acid alkyl esters such as acetates, dialkyl glutarate, dialkyl succinate, and dialkyl adipic acid.

Examples of the ether solvent include alkyl ethers such as diethyl ether and ethyl butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, and triethylene. Cyclic ethers, such as glycol ethers, such as glycol diethyl ether, and tetrahydrofuran, etc. are mentioned.

Acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone etc. are mentioned as a ketone solvent.

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

At the time of the reaction, it is preferable to use a catalyst to promote the reaction, and the amount of the catalyst used is the reactants, that is, the epoxy resin (a), the carboxylic acid compound (b), the compound (c) used as needed, and the case It is usually 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the reactants to which the solvent and others are added according to. The reaction temperature at that time is usually 60 to 150°C, and the reaction time is preferably 5 to 60 hours. Specific examples of the catalyst that can be used include, for example, triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, triphenylphosphine, triphenylstibine, and methyltriphenylstiline. Known general basic catalysts, such as bean, chromium octanoate, and zirconium octanoate, etc. are mentioned.

In addition, as a thermal polymerization inhibitor, hydroquinone monomethyl ether, 2-methylhydroquinone, hydroquinone, diphenylpicrylhydrazine, diphenylamine, 3,5-di-t-butyl-4hydroxytoluene, etc. are used. It is desirable to do

This reaction makes the end point the time point when the acid value of the sample becomes 5 mg·KOH/g or less, preferably 3 mg·KOH/g or less, while appropriately sampling.

As a preferable molecular weight range of the reactive epoxy carboxylate compound (E) obtained in this way, the weight average molecular weight in terms of polystyrene in GPC is in the range of 1,000 to 50,000, more preferably 2,000 to 30,000.

When the molecular weight is smaller than this, the toughness of the cured product is not sufficiently exhibited, and when it is too large, the viscosity increases and coating or the like becomes difficult.

Next, the acid addition step will be described in detail. The acid addition step is performed for the purpose of obtaining a reactive polycarboxylic acid compound (A) by introducing a carboxy group into the reactive epoxy carboxylate compound (E) obtained in the previous step. That is, a carboxyl group is introduced through an ester bond by subjecting a polybasic acid anhydride (d) to an addition reaction to the hydroxyl group generated by the carboxylation reaction.

As specific examples of the polybasic acid anhydride (d), any compound having an acid anhydride structure in the molecule can be used. Phthalic acid, hexahydrophthalic anhydride, itaconic anhydride, 3-methyl-tetrahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, trimellitic anhydride or maleic anhydride are particularly preferred.

The reaction of adding the polybasic acid anhydride (d) can be performed by adding the polybasic acid anhydride (d) to the carboxylate reaction solution. The addition amount should be appropriately changed depending on the use.

The addition amount of the polybasic acid anhydride (d) is, for example, when the reactive polycarboxylic acid compound (A) of the present invention is to be used as an alkali developing type resist, the polybasic acid anhydride (d) is finally obtained. It is preferable to add a calculated value such that the solid acid value (based on JISK5601-2-1:1999) of (A) is 40 to 120 mg·KOH/g, more preferably 60 to 120 mg·KOH/g. When the solid content acid value at this time is within this range, the alkali solution developability of the photosensitive resin composition of the present invention shows good developability. That is, good patterning performance and a wide management range for overdevelopment are also provided, and there is no case where excessive acid anhydrides remain.

In the reaction, it is preferable to use a catalyst to promote the reaction, and the amount of the catalyst used is obtained from the reactants, that is, the epoxy compound (a), the carboxylic acid compound (b), and the compound (c) used as needed. It is usually 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the reactive epoxy carboxylate compound (E), the polybasic acid anhydride (d), and optionally the solvent and the like added. The reaction temperature at that time is usually 60 to 150°C, and the reaction time is preferably 5 to 60 hours. Specific examples of the catalyst that can be used include, for example, triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, triphenylphosphine, triphenylstibine, and methyltriphenylstiline. Bin, chromium octanoate, zirconium octanoate, etc. are mentioned.

This acid addition reaction can be reacted without a solvent or diluted with a solvent. As a solvent that can be used here, there is no limitation in particular as long as it is an inert solvent with respect to the acid addition reaction. In addition, in the case of manufacturing using a solvent in the carboxylation reaction, which is a previous step, it is directly supplied to the acid addition reaction, which is the next step, without removing the solvent, provided that both reactions are inert. You may. The solvent that can be used is preferably the same as that used in the carboxylation reaction.

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

In addition to this, it can be carried out alone or in a mixed organic solvent, such as the reactive compound (B) described later. In this case, when used as a curable composition, it is preferable because it can be directly used as a composition.

In addition, it is preferable to use the same thing as the example in the said carboxylation reaction for a thermal polymerization inhibitor etc.

This reaction is set as the end point as the point where the acid value of the reactant falls within the range of plus or minus 10% of the set acid value while appropriately sampling.

As a preferable molecular weight range of the reactive polycarboxylic acid compound (A), the weight average molecular weight in terms of polystyrene in GPC is 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.

Examples of the reactive compound (B) that can be used in the present invention include so-called reactive oligomers such as radical reactive acrylates, cation reactive other epoxy compounds, and vinyl compounds sensitive to both. .

Examples of radical reactive acrylates include monofunctional (meth)acrylates, bifunctional (meth)acrylates, trifunctional (meth)acrylates, urethane (meth)acrylate oligomers, and polyester (meth)acrylates. ) Acrylate oligomer, epoxy (meth)acrylate oligomer, etc. are mentioned.

As a monofunctional (meth)acrylate, it is acryloyl morpholine, for example; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Cyclohexane-1,4-dimethanol mono(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, isobornyl(meth)acrylate, dicyclopentanyl(meth)acrylate, dicyclopentenyl(meth)acrylate ) acrylate, aliphatic (meth)acrylates such as dicyclopentenyloxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenyl (poly)ethoxy (meth)acrylate, p-cumylphenoxy Ethyl (meth)acrylate, tribromophenyloxyethyl (meth)acrylate, phenylthioethyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, phenylphenol (poly) Aromatic (meth)acrylates, such as oxy (meth)acrylate and phenyl phenol epoxy (meth)acrylate, are mentioned.

Examples of the bifunctional (meth)acrylate include 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, 1,9-nonanedioldi(meth)acrylate, and tricyclodecane. Dimethanol (meth)acrylate, bisphenol A (poly)ethoxydi (meth)acrylate, bisphenol A (poly)propoxydi (meth)acrylate, bisphenol F (poly)ethoxydi (meth)acrylate, ethylene glycol Di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate di(meth)acrylate of ε-caprolactone adduct of hydroxypivalic acid neopentyl glycol (for example, manufactured by Nippon Kayaku Co., Ltd.) , KAYARAD HX-220, HX-620, etc.).

Examples of trifunctional or higher polyfunctional (meth)acrylates include ditrimethylolpropane tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethyloloctane tri(meth)acrylate, and trimethylolpropane polyethoxytri. methylols such as (meth)acrylate, trimethylolpropane (poly)propoxytri(meth)acrylate, and trimethylolpropane(poly)ethoxy(poly)propoxytri(meth)acrylate; Pentaerythritol tri(meth)acrylate, pentaerythritol polyethoxytetra(meth)acrylate, pentaerythritol(poly)propoxytetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipenta erythritols such as erythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; tris[(meth)acryloyloxyethyl]isocyanurate, caprolactone-modified tris[(meth)acryloyloxyethyl]isocyanurate, etc.; and succinic acid-modified pentaerythritol triacrylate and succinic acid-modified dipentaerythritol pentaacrylate.

Examples of the (poly)ester (meth)acrylate oligomer include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, polyethylene glycol, and (poly)propylene glycol. glycols such as 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, straight-chain or branched alkyldiols such as 2-butyl-2-ethyl-1,3-propanediol, cyclohexane-1,4-dimethanol Diol compounds such as alicyclic alkyldiols such as bisphenol A (poly) ethoxydiol, or bisphenol A (poly) propoxydiol and (poly) ester diol, which is a reaction product of the dibasic acid or its anhydride, ( A reactant of meth)acrylic acid, etc. are mentioned.

Examples of the urethane (meth)acrylate oligomer include diol compounds (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 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-di Ethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, cyclohexane-1,4-dimethanol, polyethylene glycol, polypropylene glycol, bisphenol A polyethoxydiol, bisphenol A polypropoxydiol, etc.) or these diol compounds and dibasic acids or their anhydrides (eg, succinic acid, adipic acid, azelaic acid, dimer acid, isophthalic acid, terephthalic acid, phthalic acid or their anhydrides) polyesters Diols and organic polyisocyanates (e.g., tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, etc. chain saturated hydrocarbon isocyanates , isophorone 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-tolylene diisocyanate, 1,3-xylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate, 6-isopropyl-1,3- Aromatic polyisocyanate, such as phenyl diisocyanate and 1,5-naphthalene diisocyanate) was made to react, and the reactant etc. which were then added with the hydroxyl-containing (meth)acrylate are mentioned.

The epoxy (meth)acrylate oligomer is a carboxylate compound of a compound having an epoxy group and (meth)acrylic acid. For example, phenol novolak type epoxy (meth)acrylate, cresol novolak type epoxy (meth)acrylate, trishydroxyphenylmethane type epoxy (meth)acrylate, dicyclopentadiene phenol type epoxy (meth)acrylate rate, bisphenol A type epoxy (meth)acrylate, bisphenol F type epoxy (meth)acrylate, biphenol type epoxy (meth)acrylate, bisphenol-A novolak type epoxy (meth)acrylate, naphthalene backbone-containing epoxy ( meth) acrylate, glyoxal type epoxy (meth) acrylate, heterocyclic epoxy (meth) acrylate, and the like are exemplified.

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. As styrenes, styrene, methyl styrene, ethyl styrene, etc. are mentioned. Other vinyl compounds include triallyl isocyanurate and trimethallyl isocyanurate.

In addition, as a cation-reactive monomer, if it is a compound which generally has an epoxy group, there will be no limitation in particular. For example, 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-epoxycyclohexane carboxylate, vinylcyclohexene Dioxide (“ELR-4206” manufactured by Union Carbide, etc.), limonene dioxide (“Celloxide 3000” manufactured by Daicel Co., Ltd., etc.), allylcyclohexene dioxide, 3,4,-epoxy-4-methyl Cyclohexyl-2-propylene oxide, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-m-dioxane, bis(3,4-epoxycyclohexyl)adi Fate ("Cyracure UVR-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. are mentioned.

Among these, as the reactive compound (B), monofunctional, bifunctional, or trifunctional (meth)acrylates are most preferred from the viewpoint of good polymerizability and improvement in strength of the obtained spacer or the like.

The reactive compound (B) of the present invention may be used alone or in combination of two or more. The proportion of the reactive compound (B) used in the composition is preferably 30 to 250 parts by mass, more preferably 50 to 200 parts by mass, based on 100 parts by mass of the reactive polycarboxylic acid compound (A). When the amount of the reactive compound (B) used is 30 to 250 parts by mass, the sensitivity of the composition and the heat resistance and elastic properties of the obtained cured product and the like become better.

The photopolymerization initiator (C) of the present invention is an active species capable of initiating polymerization of the reactive polycarboxylic acid compound (A) and a reactive compound (B) other than the reactive polycarboxylic acid compound (A) in response to active energy rays. is a component that causes As such a photoinitiator (C), an acylphosphine compound, a benzoyloxime compound, an acetophenone compound, a biimidazole compound, etc. are mentioned.

Among them, by using an acylphosphine compound and a benzoyloxime compound together as a photopolymerization initiator, even without performing a heat treatment step after a photocuring step by exposure, a cured product having excellent properties such as reflectance, solder heat resistance, adhesion and coating film hardness can be obtained. You can get it.

The acylphosphine-based photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator having an acylphosphine structure, and examples thereof include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6- trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethylbenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, etc. An acylphosphine oxide compound is mentioned.

The benzoyloxime-based photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator having a benzoyloxime structure, and examples thereof include 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzoyloxime) ], oxime ester compounds such as 2-propanedione-2-O-benzoyloxime and 1-phenyl-1,2-propanedione-2-O-benzoyloxime.

The blending ratio of the acylphosphine-based photopolymerization initiator and the benzoyloxime-based photopolymerization initiator is not particularly limited, but, for example, the lower limit of the compounding amount of the acylphosphine-based photopolymerization initiator relative to 1 part by mass of the benzoyloxime photopolymerization initiator is the lowering of the reflectance of the cured product. 2 parts by mass is preferable from the viewpoint of preventing, 3 parts by mass is more preferred from the viewpoint of sufficiently performing internal curing to further improve adhesion, and 4 parts by mass is particularly preferred from the viewpoint of reliably preventing a decrease in the reflectance of the cured product. On the other hand, the upper limit of the compounding amount of the acylphosphine-based photopolymerization initiator with respect to 1 part by mass of the benzoyloxime-based photopolymerization initiator is preferably 100 parts by mass from the viewpoint of reliably improving solder heat resistance and adhesion, and reliably preventing a decrease in coating film hardness. 50 parts by mass is more preferable, and 10 parts by mass is particularly preferable from the viewpoint of further improving solder heat resistance and adhesion in a well-balanced manner.

That is, the blending ratio of the acylphosphine-based photopolymerization initiator and the benzoyloxime-based photopolymerization initiator is usually about 2 to 100 parts by mass, preferably 3 to 50 parts by mass of the acylphosphine-based photopolymerization initiator relative to 1 part by mass of the benzoyloxime-based photopolymerization initiator. About 4 parts by mass, particularly preferably about 4 to 10 parts by mass is preferable.

The total compounding amount of the acylphosphine-based photopolymerization initiator and the benzoyloxime-based photopolymerization initiator is not particularly limited. 1 mass part is preferable at the point of improving the mechanical strength of hardened|cured material, and 2 mass parts is especially preferable at the point of heat resistance improvement. On the other hand, the upper limit thereof is preferably 30 parts by mass from the viewpoint of suppressing a decrease in reflectance due to discoloration due to oxidative decomposition of the photopolymerization initiator, and particularly preferably 20 parts by mass from the viewpoint of adhesion to the substrate.

That is, the total compounding amount of the acylphosphine-based photopolymerization initiator and the benzoyloxime-based photopolymerization initiator is preferably 1 to 30 parts by mass, and about 2 to 20 parts by mass is used with respect to 100 parts by mass of the reactive polycarboxylic acid compound (A). particularly preferred.

Titanium oxide (D) is blended to whiten cured products such as coating films, and examples thereof include anatase-type titanium oxide and rutile-type titanium oxide having a rutile crystal structure. Among these, rutile type titanium oxide is preferable in terms of whiteness. Examples of rutile titanium oxide include "TR-600", "TR-700", "TR-750", "TR-840" manufactured by Fuji Titanium Industry Co., Ltd., and "R" manufactured by Ishihara Industry Co., Ltd. -550”, “R-580”, “R-630”, “R-820”, “CR-50”, “CR-60”, “CR-80”, “CR-90”, “CR-93” ", "KR-270", "KR-310", and "KR-380" manufactured by Titanium Industry Co., Ltd. are exemplified. These may be used independently, and may mix and use 2 or more types.

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

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

A known antifoaming agent can be used, and examples thereof include silicone type, hydrocarbon type, acrylic type and the like. Coupling agents, such as a silane type, a titanate type, and an alumina type, are mentioned to a dispersing agent, for example.

The solvent is for adjusting the viscosity or dryness of the white active energy ray-curable resin composition, and for example, ketones such as methyl ethyl ketone and cyclohexane, aromatic hydrocarbons such as toluene and xylene, methanol, isopropanol, and cyclohexane Alcohols such as alcohol, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, petroleum solvents such as petroleum ether and petroleum naphtha, cellosolves such as cellosolve and butyl cellosolve, carbitol, butylcarbitol, etc. acetic acid esters such as carbitols of , ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, and butyl carbitol acetate; and the like. These may be used individually or may mix and use 2 or more types.

The extender pigment is for supplementarily improving the mechanical strength of a cured product (eg, a coated solder resist film), and examples thereof include silica, barium sulfate, alumina, aluminum hydroxide, talc, and mica. .

Further, in the present invention, the active energy ray-curable resin composition is colored white using titanium oxide, but depending on the application, a blue colorant, a yellow colorant, or a black colorant are appropriately used within a range that does not affect the effect of the present invention. You may add coloring agents, such as a coloring agent. Specific examples of colorants other than white include organic pigments such as phthalocyanine systems such as phthalocyanine green and phthalocyanine blue, anthraquinone systems and azo systems, and inorganic pigments such as carbon black.

The method for producing the active energy ray-curable resin composition of the present invention described above is not limited to a specific method. For example, after blending each of the above components in a predetermined ratio, at room temperature, a triaxial roll, a ball mill, or a sand mill It can be produced by kneading or mixing with a kneading means such as a super mixer or a stirring means such as a planetary mixer. In addition, you may pre-knead or pre-mix as needed before the said kneading or mixing.

Next, a method of using the white active energy ray-curable resin composition of the present invention described above is described. Here, the case where the white active energy ray-curable resin composition of this invention is coated as a solder resist film on a circuit board is taken as an example and demonstrated.

The white active energy ray-curable resin composition of the present invention obtained as described above is applied, for example, to a printed wiring board having a circuit pattern formed by etching copper foil, screen printing, spray coater, bar coater, applicator, blade coater, It is applied to a desired thickness using a known coating method such as a knife coater, a roll coater, or a gravure coater. After coating, if necessary, pre-drying by heating at a temperature of about 60 to 80° C. for about 15 to 60 minutes to volatilize the solvent in the white active energy ray-curable resin composition may be performed to form a tack-free coating film. On the white active energy ray-curable resin composition applied using a known coating method, a negative film having a light-transmitting pattern except for the lands of the circuit pattern is adhered, and an active energy ray (e.g., , ultraviolet rays) to photocur the coating film. Next, a target solder resist film can be formed on the printed wiring board by removing the unexposed region corresponding to the land with a dilute alkali aqueous solution and developing the coating film. A spray method, a shower method, etc. are used for the above developing method, and the dilute alkaline aqueous solution used is not particularly limited, and examples thereof include a 0.5 to 5% sodium carbonate aqueous solution. In the case where it is not necessary to develop the coating film, the white active energy ray-curable resin composition may be photocured without using a negative film.

An electronic circuit unit is formed by soldering an electronic component to the circuit board coated with the solder resist film obtained in this way by a spray soldering method, a reflow soldering method, or the like.

A cured product of a photocured white active energy ray-curable resin composition and a cured film, and a 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 by examples, but the present invention is not limited by these examples. In addition, in the examples, unless otherwise specified, "part" represents a mass part, and "%" represents a mass %.

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

1) Epoxy equivalent: Measured by a method according to JISK7236:2001.

2) Softening point: measured according to JISK7234:1986.

3) Acid value: measured according to JISK0070:1992

Examples 1-1 to 1-3

[Preparation of Reactive Polycarboxylic Acid Compound (A)]

As epoxy resin (a), NC-6300H (manufactured by Nippon Kayaku; n = 0 (64%), n = 1 (23%), n = 2 or more (13%) of general formula (1); epoxy equivalent 230 g / eq.) as the amount described in Table 1, and acrylic acid (abbreviated name AA, Mw = 72) as the compound (b) as the amount described in Table 1 and dimethylolpropionic acid (abbreviated name DMPA, Mw = 134) as the compound (c) in Table 1 Medium amount was added. 3 g of triphenylphosphine as a catalyst and propylene glycol monomethyl ether monoacetate as a solvent were added so that the solid content was 80% by mass of the reaction solution, and reacted at 100 ° C. for 24 hours to obtain a reactive epoxy carboxylate compound (E) solution. . The solid acid value (AV: mg·KOH/g) of 5 or less was set as the reaction end point, and the reaction proceeded to the next one. The acid value was measured in the reaction solution and converted into an acid value as a solid content.

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

Comparative Example 1-1, 1-2

[Preparation of reactive polycarboxylic acid compound for comparison]

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 200 g/eq.) in the amount described in Table 1. Other than that, a carboxylate compound solution was obtained in the same manner as in Examples 1-1 to 1-3.

Subsequently, a reactive polycarboxylic acid compound solution for comparison was obtained in the same manner as in Examples 1-1 to 1-3. The solid content acid value (AV: mg·KOH/g) is shown in Table 1.

Comparative Example 1-3

[Preparation of reactive polycarboxylic acid compound having no aromatic ring for comparison]

In a 2-liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen inlet tube, 900 g of diethylene glycol dimethyl ether as a solvent and t-butyl-peroxy-2-ethylhexanoate as a polymerization initiator ( 21.4 g of PERBUTYL®O manufactured by Nippon Oil & Oil Co., Ltd. was added and heated to 90°C. After heating, here, 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.) were added as a polymerization initiator. Added dropwise over 3 hours along with 21.4 g of bis(4-t-butylcyclohexyl)peroxydicarbonate (PEROYL TCP manufactured by Nippon Oil & Oil Co., Ltd.) and further aged for 6 hours to contain a carboxyl group A copolymer resin was obtained. In addition, the reaction was performed in a nitrogen atmosphere.

Next, 363.9 g of 3,4-epoxycyclohexylmethyl acrylate (CYCLOMER A200 manufactured by Daicel Co., Ltd.), 3.6 g of dimethylbenzylamine as a ring-opening catalyst, and polymerization inhibitor were added to the obtained carboxy group-containing copolymer resin. As a result, 1.80 g of hydroquinone monomethyl ether was added, heated at 100°C, and stirred to carry out ring-opening addition reaction of epoxy. After 16 hours, a solution containing 65 mass% (solid content) of a carboxy group-containing resin having no aromatic ring having an acid value of 108.9 mg·KOH/g and a weight average molecular weight of 25,000 in the solid content was obtained.

<Preparation of the composition of the present invention>

Each component shown in Table 2 was blended in the blending ratio shown in Table 2 below, and mixed and dispersed at room temperature using a 3-roll roll, Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3 A white active energy ray-curable resin composition used in was prepared.

Details of each component used in Examples and Comparative Examples are shown.

<Reactive compound (B)>

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

<Photoinitiator (C)>

C-1: Acylphosphine-based photopolymerization initiator

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

C-2: Benzoyloxime-based photopolymerization initiator

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

<Titanium oxide (D)>

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

<Preparation of test piece>

The surface of a printed wiring board on which a circuit pattern is formed on a copper-clad laminate (FR-4, thickness 1.6 mm, conductor thickness 35 μm) is polished with a buff (polishing ring) (corresponding English word: mopping, or buffing, or polishing) dealt with Next, the compositions of the present invention of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3 were respectively applied to printed wiring boards by a screen printing method. Thereafter, the printed wiring board thus produced was dried at 80°C for 30 minutes in a hot air circulation type drying furnace. The composition of the present invention is exposed to ultraviolet rays (wavelength: 300 to 400 nm) at 2000 mJ/cm 2 (photocuring step) with an exposure device (Oak Manufacturing Co., Ltd., type HMW-680GW) on the coated film of the printed wiring board after drying. A cured coating film was formed and a test piece was produced. The thickness of the cured coating film was 15 to 20 µm.

<evaluation>

The following evaluation was performed about the test pieces formed from the compositions of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3 and their coating films. An evaluation result is combined with Table 3 and shown.

(1) Reflectance

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

(2) light fastness

The obtained test piece was further irradiated with super UV (90 mW) light for 24 hours to accelerate deterioration, and then, using a spectrophotometer U-3310H (manufactured by Hitachi, Ltd.: φ60 mm integrating sphere), color change was measured. Measured. ΔE*ab represents a change in color. The smaller this value is, the smaller the change in color is.

(3) Solder heat resistance

The cured coating film of the test piece was immersed in a solder bath at 260 ° C. for 10 seconds in accordance with the test method of JIS C-6481, followed by a peeling test (peeling test) using cellophane tape as one cycle, and the coating film after repeating this 1 to 2 times The state was visually observed and evaluated according to the following criteria.

○: No change was observed in the coating film even after repeating 2 cycles.

(triangle|delta): A change is confirmed in the coating film after repeating 2 cycles.

x: Peeling is observed in the coating film after repeating 1 cycle.

(4) Adhesion

In accordance with JIS K-5600-5-6, 100 crosscuts (10 × 10) of 1 mm are formed on the test piece, and a peeling test (peeling test) is performed with cellophane tape, and the peeling state of the crosscut is visually observed. was observed, and the number of lattice patterns not peeled off from the substrate was counted among 100 crosscuts.

(5) Coating hardness

According to the test method of JIS K-5600-5-4, a 3B to 9H pencil sharpened so that the tip of the core is flat is pressed against the cured coating film on the copper foil of the test piece at an angle of 45 degrees, and the coating film is peeled off. The hardness of the pencil was recorded so that this did not occur.

As is clear from the above results, the white active energy ray-curable compositions containing the reactive polycarboxylic acid compound (A) in the present invention of Examples 2-1 to 2-3 were compared to those of Comparative Examples 2-1 to 2- Compared to the composition of No. 3, it was found that the reflectance, light resistance, and solder heat resistance were good, and the adhesiveness and coating film hardness were excellent. Further, Examples 2-1 and 2-2 in which DMPA (compound (c)) was also used for preparation of the reactive polycarboxylic acid compound (A) were compared to Example 2-3 in which compound (c) was not used. In comparison, it was found to exhibit better adhesiveness.

Since the white active energy ray-curable resin composition of the present invention can obtain a cured product having excellent reflectance, solder heat resistance, adhesion, and coating film hardness even without performing a thermal curing step after the photocuring step, for example, solder for printed wiring boards It is highly useful in the field of resist film and cover lay.

Claims (6)

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), a photopolymerization initiator (C), and titanium oxide (D), comprising: A carboxylic acid compound (A) is an epoxy resin represented by Formula (1) (a) and a compound (b) having one or more polymerizable ethylenically unsaturated groups and one or more carboxy groups in one molecule, and at least two in one molecule A white active energy ray-curable resin composition, which is a reactive polycarboxylic acid compound (A) obtained by further reacting a polybasic acid anhydride (d) with a reactant (E) of a compound (c) having at least one hydroxyl group and at least one carboxy group:

(In the formula, n represents an integer of 0 to 2). delete According to claim 1,
The photopolymerization initiator (C) is an acylphosphine-based photopolymerization initiator and a benzoyloxime-based photopolymerization initiator, and the blending ratio thereof is 2 to 100 parts by mass of the acylphosphine-based photopolymerization initiator with respect to 1 part by mass of the benzoyloxime-based photopolymerization initiator. A curable resin composition. According to claim 3,
The acylphosphine photopolymerization initiator is 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethylbenzoyl)-2 , 4,4-trimethyl-pentylphosphine oxide and (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, and at least one selected from the group consisting of benzoyl oxime photopolymerization initiator is 1,2-octane Dione-1-[4-(phenylthio)-2-(O-benzoyloxime)], 2-propanedione-2-O-benzoyloxime, 1-phenyl-1,2-propanedione-2-O-benzoyl A white active energy ray-curable resin composition of at least one member selected from the group consisting of oximes. A cured product of the white active energy ray-curable resin composition according to any one of claims 1, 3 and 4. A printed wiring board having a cured coating of the white active energy ray-curable resin composition according to any one of claims 1, 3 and 4.