JP5430884B2 - Curable composition capable of alkali development and cured product thereof - Google Patents

Description

  The present invention relates to a curable composition used for forming a solder resist or the like of a printed wiring board, and more particularly to a curable composition containing a carboxyl group-containing novolac resin and a cured product thereof.

  Currently, as a curable composition used for forming a solder resist on a printed wiring board, a composition using a light and thermosetting resin that can be developed with a dilute alkaline aqueous solution has become mainstream in consideration of environmental problems. ing. As such a curable composition, for example, a curable composition using a curable resin obtained by adding an acid anhydride to a reaction product of a novolak-type epoxy resin and an unsaturated group-containing monocarboxylic acid (see Patent Document 1), 1 Epihalohydrin is reacted with an alcoholic secondary hydroxyl group obtained by reacting an aromatic epoxy resin having two glycidyl groups in the molecule with an aromatic alcohol resin having two phenolic hydroxyl groups in one molecule. Examples thereof include a curable composition using a curable resin obtained by adding an unsaturated group-containing monocarboxylic acid and then an acid anhydride to the obtained reaction product (see Patent Document 2).

Thus, several curable compositions have been proposed in the past, and are currently widely used in the production of actual printed wiring boards.
In recent years, printed wiring boards have been densified along with the reduction in size and size of electronic equipment, and higher performance of solder resists is required in response to the higher density of printed wiring boards. That is, when manufacturing a high-density printed wiring board, the curable composition that has been commercially available in the past does not have sufficient developability, and the resolution corresponding to the increase in density is poor. In addition, in a high-density printed wiring board in which a solder resist is formed using a conventional curable composition, there are problems such as a decrease in flexibility, a decrease in electrical insulation under high temperature and high humidity, and a whitening phenomenon. ing.

As a curable composition that solves the problem of flexibility, the alcoholic secondary hydroxyl group of bisphenol A type epoxy resin is reacted with epihalohydrin, and then the resulting polyfunctional epoxy resin is added per epoxy equivalent. Carboxyl obtained by reacting 0.2 to 1.2 mol of ethylenically unsaturated carboxylic acid and further reacting 0.2 to 1.0 mol of polybasic carboxylic acid and / or anhydride thereof per epoxy equivalent A curable composition using a group-containing photosensitive prepolymer has been proposed (see Patent Document 3).
Patent Document 4 discloses a reaction product of a mixture of a novolac type epoxy resin and a rubber-modified bisphenol A type epoxy resin and 0.2 to 1.2 mol of ethylenically unsaturated carboxylic acid per epoxy equivalent of the mixture; A curable composition using a photosensitive prepolymer having a carboxyl group, which is a reaction product of 0.2 to 1.0 mol of a polybasic carboxylic acid and / or an anhydride thereof per epoxy equivalent of the above mixture. It is disclosed.

Furthermore, in Patent Document 5, an epoxy resin having two or more glycidyl groups in one molecule is reacted with an ethylenically unsaturated monocarboxylic acid and a polybasic acid at a predetermined ratio, and 1 of the obtained reactants. A part of the primary and / or secondary hydroxyl groups are esterified with an ethylenically unsaturated monocarboxylic acid chloride, and some or all of the remaining hydroxyl groups in the resulting reaction product are converted into polybasic acids and A curable composition using a vinyl ester resin obtained by esterification with a polybasic acid anhydride is disclosed.
A resist film obtained using the curable composition is excellent in flexibility. However, with the curable composition, sufficient developability corresponding to the increase in the density of printed wiring boards accompanying the recent reduction in the thickness and size of electronic devices cannot be obtained.

On the other hand, as a curable composition that solves the problems of flexibility and electrical insulation, a reaction product obtained by reacting a reaction product of a novolak type phenol resin and an alkylene oxide with an unsaturated group-containing monocarboxylic acid. A curable composition using a carboxyl group-containing photosensitive resin obtained by reacting a product with a polybasic acid anhydride (see Patent Document 6), a reaction product of a novolac-type phenol resin and an alkylene oxide or a cyclic carbonate. Carboxyl group-containing photosensitive resin obtained by reacting unsaturated group-containing monocarboxylic acid and saturated aliphatic monocarboxylic acid and / or aromatic monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride A curable composition (see Patent Document 7) and the like have been proposed. However, these compositions are inferior in developability. Further, a high-density printed wiring board in which a resist is formed using the above composition is excellent in electrical insulation at high temperatures and high humidity, but has low hardness and whitens.
JP-A 61-243869 JP-A-5-32746 JP-A-11-65117 Japanese Patent Laid-Open No. 9-5997 JP 2004-067815 A International Publication WO 02/024774 A1 JP 2005-91783 A

The present invention has been made in view of the above problems, and has excellent developability, hardness, solder heat resistance, chemical resistance, adhesion, PCT (pressure cooker test) resistance, and electroless gold plating. An object of the present invention is to provide a curable composition capable of forming a cured film having excellent properties such as resistance, whitening resistance, electrical insulation and flexibility, and a cured product thereof.

（式中、Ｒ_１〜Ｒ_４はそれぞれ水素原子又はメチル基、Ｘ_１、Ｘ_２は同一又は異なるモノカルボン酸残基、Ｙはジカルボン酸残基、ｎ１〜ｎ３は同一又は異なる１以上の整数、ｎ４は０以上の整数を表わす。）、
（Ｂ）感光性（メタ）アクリレート化合物、及び
（Ｃ）光重合開始剤
を含有することを特徴とする。 The alkali-developable curable composition according to the present invention, which has been made to achieve the above object,
(A) It consists of structural units represented by the following general formulas (1), (2), (3) and (4), and has an acid value of 20 to 131 mgKOH / g, an epoxy equivalent of 3000 g / eq. A carboxyl group-containing novolac resin that is soluble in an organic solvent as described above

Wherein R _{1 to} R ₄ are each a hydrogen atom or a methyl group, X ₁ and X ₂ are the same or different monocarboxylic acid residues, Y is a dicarboxylic acid residue, and n1 to n3 are the same or different integers. N4 represents an integer of 0 or more).
It contains (B) a photosensitive (meth) acrylate compound, and (C) a photopolymerization initiator.

According to a specific preferred embodiment of the present invention, the carboxyl group-containing novolak resin, which is one component of the curable composition, is such that in the general formulas (1) and (2), X ₁ and X ₂ are not present. Saturated group-containing monocarboxylic acid residue, or X ₁ is an unsaturated group-containing monocarboxylic acid residue, X ₂ is a monocarboxylic acid residue that does not contain an unsaturated group, or X ₁ and X ₂ are each an unsaturated group. It is a monocarboxylic acid residue not contained.

  According to a more specific preferred embodiment, the carboxyl group-containing novolac resin, which is one component of the curable composition, is partially bonded to the epoxy group of the novolac epoxy resin (a). To the unsaturated group-containing monocarboxylic acid (b) and the same or different unsaturated group-containing monocarboxylic acid (b ′), and the epoxy group of the resulting reaction product (c) is added to the dicarboxylic acid (d). Or an epoxy group of the novolak-type epoxy resin (a) partially added with the unsaturated group-containing monocarboxylic acid (b), and then the reaction product (c ′ The dicarboxylic acid (d) is partially added to the epoxy group of (2), and the unsaturated group-containing monocarboxylic acid (b ′) is further added to the epoxy group of the obtained reaction product (e). Gain Or obtained by subjecting the epoxy group of the reaction product (e) to an addition reaction with a monocarboxylic acid (f) not containing an unsaturated group, or a part of the epoxy group of the novolac epoxy resin (a). Then, an unsaturated group-containing monocarboxylic acid (b) and an unsaturated group-free monocarboxylic acid (f) are subjected to an addition reaction, and then the epoxy group of the resulting reaction product (g) is converted to a dicarboxylic acid (d). Or a monocarboxylic acid (f) that does not partially contain an unsaturated group is added to the epoxy group of the novolak-type epoxy resin (a), and then the reaction product ( h) an epoxy group of the dicarboxylic acid (d) is partially subjected to an addition reaction, and an epoxy group of the obtained reaction product (i) is further subjected to an addition reaction of an unsaturated group-containing monocarboxylic acid (b). can get The unsaturated group-containing monocarboxylic acid (b) is acrylic acid or methacrylic acid, the dicarboxylic acid (d) is a carboxylic acid soluble in the solvent soluble and / or the reaction temperature in the reaction solvent preferred.

  According to the present invention, the developability required for a curable composition capable of supporting high density printed wiring boards is sufficiently satisfied, and the hardness, solder heat resistance, chemical resistance, adhesion, and PCT resistance are satisfied. A cured film excellent in electroless gold plating resistance, whitening resistance, electrical insulation, flexibility and the like can be obtained.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have novolak-type carboxyl group containing the structural unit represented by the general formulas (1), (2), (3) and (4). A resin-containing composition has excellent developability, and has excellent hardness, solder heat resistance, chemical resistance, adhesion, PCT resistance, electroless gold plating resistance, whitening resistance, electrical insulation, and flexibility. The present invention has been found to give a product, and the present invention has been completed.

  That is, the carboxyl group-containing novolac resin, which is a component of the curable composition of the present invention, has excellent developability because a secondary alcoholic hydroxyl group is present in any side chain, and also has an unsaturated group. And the carboxyl group is located at the end of the side chain, so that the reactivity is excellent. And the composition which added the photosensitive (meth) acrylate compound and the photoinitiator to such a carboxyl group-containing novolak-type resin gives the hardened | cured material with a high crosslinking density and the outstanding characteristic.

Hereinafter, the curable composition of the present invention will be described in detail.
First, the carboxyl group-containing novolak resin (A), which is a component of the present invention, has a monocarboxylic acid residue and a carboxyl group located at the end of each side chain, and secondary alcoholic groups in all side chains. Although it has a hydroxyl group, it is characterized in that no primary alcoholic hydroxyl group exists in any side chain. Such a structure can be obtained by various methods. For example, a monocarboxylic acid (bf) and the same or different monocarboxylic acid (b′f) are partially added to the epoxy group of the novolak-type epoxy resin (a), and the resulting reaction product (ch) Of the remaining epoxy group of dicarboxylic acid (d) (hereinafter, the structure obtained by this method is referred to as K), and the epoxy group of the novolac epoxy resin (a) is partially monocarboxylic acid (Bf) is subjected to an addition reaction, and then an epoxy group of the obtained reaction product (c′h) is partially subjected to an addition reaction with a dicarboxylic acid (d), and the remaining reaction product (ei) remaining is obtained. And the like, and a method of adding a monocarboxylic acid (b′f) to the epoxy group (hereinafter, the structure obtained by this method is referred to as “N”). It is easily carried out in a solvent or without a solvent.

  In order to obtain the structure K, a monocarboxylic acid (bf) and the same or different monocarboxylic acid (b′f) are partially added to the epoxy group of the novolak-type epoxy resin (a) to obtain a reaction product. (Ch) is obtained, and in this case, it is preferable to carry out the reaction in a solvent using a polymerization inhibitor and a catalyst, and the reaction temperature is preferably 50 to 150 ° C, more preferably 70 to 120 ° C. Although it is preferable to react the monocarboxylic acid (bf) and (b′f) at a ratio of 0.3 to 0.9 mol in total with respect to 1 equivalent of the epoxy group of the novolak type epoxy resin (a), More preferably, it is 0.5-0.8 mol. When the monocarboxylic acids (bf) and (b′f) are out of the range of 0.3 to 0.9 mol in total, gelation in the subsequent reaction or developability of the final product cannot be sufficiently obtained. There is a fear. When the monocarboxylic acid (bf) and / or (b′f) is an unsaturated group-containing monocarboxylic acid, the photocurability of the final product is obtained.

Representative examples of the monocarboxylic acids (bf) and (b′f) include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, α-cyanocinnamic acid, β-styrylacrylic acid, β-furfurylacrylic. Monocarboxylic acids containing unsaturated groups such as acids, formic acid, acetic acid, propionic acid, n-butyric acid, isobutyric acid, valeric acid, trimethylacetic acid, caproic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecyl Acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid and other saturated aliphatic monocarboxylic acids, benzoic acid, alkylbenzoic acid, alkylaminobenzoic acid, halogenated benzoic acid , Aromatic monocarboxylic acids such as phenylacetic acid, anisic acid, benzoylbenzoic acid, naphthoic acid, etc. And the like. These monocarboxylic acids can be used alone or in admixture of two or more. Preference is given here to acrylic acid, methacrylic acid and acetic acid.

  Examples of the reaction solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether , Glycol ethers such as diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate , Ethylene glycol monobutyl ether Acetates such as cetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol, propylene glycol; octane, decane, etc. Aliphatic hydrocarbons; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. These reaction agents (organic solvents) can be used alone or as a mixture of two or more.

Examples of the reaction catalyst include tertiary amines such as triethylamine, quaternary ammonium salts such as triethylbenzylammonium chloride, imidazole compounds such as 2-ethyl-4-methylimidazole, phosphorus compounds such as triphenylphosphine, naphthenic acid, and laurin. Examples include metal salts of organic acids such as lithium, chromium, zirconium, potassium, and sodium of acid, stearic acid, oleic acid, and octoenoic acid, but are not limited to these, alone or in combination of two or more. May be used.

Examples of the polymerization inhibitor include hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, and phenothiazine, but are not limited to these and may be used alone or in combination of two or more. it can.

  Carboxyl which is one component of the composition of the present invention is obtained by subjecting the epoxy group of the reaction product (ch) to addition reaction of 1.0 mol or more of dicarboxylic acid (d) with respect to 1 equivalent of epoxy group. The structure K of the group-containing novolac resin is obtained, and the dicarboxylic acid (d) is preferably soluble in the reaction solvent and / or melted in the solvent at the reaction temperature. When dicarboxylic acid (d) that is insoluble in the reaction solvent and / or does not melt in the solvent at the reaction temperature is added to the reaction product (ch), the dicarboxylic acid (d) is sufficiently contained in the reaction product (ch). This is because they may not be added or gelled. The reaction temperature is preferably 50 to 150 ° C, more preferably 70 to 120 ° C. The reaction amount of the novolak-type epoxy resin (a), monocarboxylic acid (bf) and dicarboxylic acid (d) is such that the monocarboxylic acid (bf) and dicarboxylic acid (bf) and dicarboxylic acid (d) are equivalent to 1 equivalent of the epoxy group of the novolak-type epoxy resin (a). The total amount of the acid (d) is preferably 0.94 to 1 mol. The epoxy equivalent of the reaction product was 3000 g / eq. Above, but preferably 5000 g / eq. That's it. Epoxy equivalent is 3000 g / eq. Below, it gels and becomes insoluble in an organic solvent, or developability of the final product is not sufficiently obtained due to polymerization.

Representative examples of the dicarboxylic acid (d) include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, Examples include isophthalic acid, terephthalic acid, and tetrahydrophthalic acid. These dicarboxylic acids can be used alone or in admixture of two or more. Preference is given here to dicarboxylic acids (d) which are soluble in the reaction solvent and / or melt into the solvent at the reaction temperature, more preferred are malonic acid, glutaric acid, maleic acid, tetrahydrophthalic acid and phthalic acid, Particularly preferred are maleic acid, tetrahydrophthalic acid and phthalic acid.

  In addition, the monocarboxylic acid (bf) is partially added to the epoxy group of the novolak-type epoxy resin (a), and the dicarboxylic acid (c′h) is partially added to the epoxy group of the obtained reaction product (c′h). d) is subjected to an addition reaction, and the remaining epoxy group of the obtained reaction product (ei) is further subjected to an addition reaction with a monocarboxylic acid (b′f) to obtain the structure N of the carboxyl group-containing novolak resin of the present invention. However, the role of the addition of the monocarboxylic acids (bf) and (b′f) is to suppress the crosslinking reaction of the dicarboxylic acid (d) with respect to the reaction product (c′h). Therefore, the reaction time of the reaction product (c′h) and the dicarboxylic acid (d) must not be increased. If these reaction times are long, the dicarboxylic acid (d) may act as a crosslinking agent for the reaction product (c′h). The reaction temperature is preferably 50 to 150 ° C, more preferably 70 to 120 ° C. Further, the monocarboxylic acid (bf) is reacted at a ratio of 0.3 to 0.85 mol with respect to 1 equivalent of the epoxy group of the novolac type epoxy resin (a), and the reaction product (c′h) It is preferable to react the dicarboxylic acid (d) at a ratio of 0.3 to 0.95 mol with respect to 1 equivalent of the epoxy group. The remaining epoxy groups of the reaction product (ei) thus obtained are preferably reacted with a monocarboxylic acid (b′f) at a ratio of 1.0 mol or more per 1 equivalent of the epoxy groups. .

  The acid value of the carboxyl group-containing novolac resin is 20 to 131 mgKOH / g, preferably 33 to 111 mgKOH / g. From these ranges, the curable composition of the present invention has excellent characteristics not only in developability but also in other various characteristics.

Examples of the photosensitive (meth) acrylate compound (B) include hydroxyl group-containing acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, pentaerythritol triacrylate, and dipentaerythritol pentaacrylate. Water-soluble acrylates such as polyethylene glycol diacrylate and polypropylene glycol diacrylate; polyfunctional polyester acrylates of polyhydric alcohols such as trimethylolpropane tri (meth) acrylate, pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate; Multifunctional alcohols such as trimethylolpropane and hydrogenated bisphenol A or polyhydric phenols such as bisphenol A and biphenol Acrylates of ethylene oxide adduct and / or propylene oxide adduct; polyfunctional or monofunctional polyurethane acrylate which is an isocyanate modification of the above hydroxyl group-containing acrylate; bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether or phenol Epoxy acrylates that are (meth) acrylic acid adducts of novolac epoxy resins; caprolactone-modified ditrimethylolpropane tetraacrylate, ε-caprolaclone-modified dipentaerythritol acrylate, caprolactone-modified hydroxypivalic acid neopentyl glycol ester diacrylate, etc. Acrylates and methacrylates corresponding to the above acrylates. Can be used alone or in combination of two or more. Among these, a polyfunctional (meth) acrylate compound having two or more (meth) acryloyl groups in one molecule is preferable. The purpose of using these photosensitive (meth) acrylate compounds is to increase the photoreactivity of the carboxyl group-containing novolac resin (A). The photosensitive (meth) acrylate compound which is liquid at room temperature plays a role of adjusting the composition to a viscosity suitable for various coating methods and assisting in solubility in an alkaline aqueous solution, in addition to the purpose of increasing photoreactivity. However, if a large amount of liquid photosensitive (meth) acrylate compound is used at room temperature, the dryness of the coating film cannot be obtained, and the characteristics of the coating film tend to deteriorate. It is not preferable. The compounding amount of the photosensitive (meth) acrylate compound (B) is preferably 100 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing novolac resin (A). In this specification, “(meth) acrylate” is a term that collectively refers to acrylate and methacrylate, and the same applies to other similar expressions.

  Examples of the photopolymerization initiator (C) include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2, Acetophenones such as 2-diethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2- Aminoacetophenones such as dimethylamino-1- (4-morpholinophenyl) -butan-1-one, N, N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1- Chloro Anthraquinones such as nthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzoylper Organic peroxides such as oxide and cumene peroxide; 2,4,5-triarylimidazole dimer; Riboflavin tetrabutyrate; Thiols such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole Compound; Organic halogen compounds such as 2,4,6-tris-s-triazine, 2,2,2-tribromoethanol, tribromomethylphenylsulfone; benzophenone, 4,4'-bisdie Benzophenones or xanthones such as Le aminobenzophenone; and 2,4,6-trimethylbenzoyl diphenylphosphine oxide. These known and commonly used photopolymerization initiators can be used alone or as a mixture of two or more thereof. Further, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4- Photoinitiator aids such as tertiary amines such as dimethylaminobenzoate, triethylamine, triethanolamine can be added. A titanocene compound such as CGI-784 (manufactured by Ciba Specialty Chemicals Co., Ltd.) having absorption in the visible light region can also be added to promote the photoreaction. Particularly preferred photopolymerization initiators are 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butan-1-one and the like, but is not particularly limited thereto, and absorbs light in the ultraviolet light or visible light region, such as (meth) acryloyl group As long as the unsaturated group is radically polymerized, it is not limited to a photopolymerization initiator and a photoinitiator aid, and can be used alone or in combination. And the usage-amount is the ratio of 0.5-25 mass parts with respect to 100 mass parts (total amount or single amount in the case of single use) of said carboxyl group-containing novolak-type resin (A).

Moreover, the curable composition of this invention can mix | blend a thermosetting component in order to accelerate | stimulate the thermosetting of carboxyl group-containing novolak-type resin (A). The thermosetting component may be anything as long as it reacts with the carboxyl group of the carboxyl group-containing novolac resin (A) by heat. Generally, an epoxy resin, an oxetane resin, etc. are mentioned.
As the epoxy resin, for example, Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1004, Epiklone 840, Epicron 850, Epicron 1050, Epicron 1050, Epicron 2055, Toto from Japan Epoxy Resin Co., Ltd. Epototo YD-011, YD-013, YD-127, YD-128 manufactured by Kasei Chemical Co., Ltd., D.C. E. R. 317, D.E. E. R. 331, D.D. E. R. 661, D.E. E. R. 664, Sumitomo Chemical Co., Ltd. bisphenol A type epoxy resins such as Sumi-Epoxy ESA-011, ESA-014, ELA-115, ELA-128 (all trade names); manufactured by Japan Epoxy Resin Co., Ltd. Epicort YL903, Daikoku Ink Chemical Co., Ltd. Epicron 152, Epicron 165, Toto Kasei Co., Ltd. Epototo YDB-400, YDB-500, Dow Chemical Co., Ltd. E. R. 542, brominated epoxy resins such as Sumi-epoxy ESB-400 and ESB-700 (both trade names) manufactured by Sumitomo Chemical Co., Ltd .; Epicoat 152, Epicoat 154, Dow Chemical (manufactured by Japan Epoxy Resin Co., Ltd.) D. manufactured by Co., Ltd. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865, manufactured by Dainippon Ink & Chemicals, Inc. Epototo YDCN-701, YDCN-704, manufactured by Tohto Kasei Co., Ltd., manufactured by Nippon Kayaku Co., Ltd. Novolak type epoxy such as EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, Sumitomo Epoxy ESCN-195X, ESCN-220 (all trade names) manufactured by Sumitomo Chemical Co., Ltd. Resins; Bisphenols such as Epiklon 830 manufactured by Dainippon Ink & Chemicals, Ltd., Epicoat 807 manufactured by Japan Epoxy Resin, Epototo YDF-170, YDF-175, YDF-2004 manufactured by Toto Kasei Co., Ltd. (all trade names) F-type epoxy resin; Epototo ST-2004, ST-2 manufactured by Tohto Kasei Co., Ltd. Hydrogenated bisphenol A type epoxy resin such as 07 and ST-3000 (all are trade names); Epicoat 604 manufactured by Japan Epoxy Resin Co., Ltd., Epototo YH-434 manufactured by Toto Kasei Co., Ltd., Sumitomo Chemical Co., Ltd. Glycidylamine type epoxy resin such as Sumi-Epoxy ELM-120 (both trade names) manufactured by Daicel Chemical Industries Ltd. Alicyclic epoxy resin such as Celoxide 2021 (trade name) manufactured by Daicel Chemical Industries, Ltd .; Japan Epoxy Resin Co., Ltd. YL-933 manufactured by Nippon Kayaku Co., Ltd., EPPN-501 manufactured by Nippon Kayaku Co., Ltd., trihydroxyphenylmethane type epoxy resin such as EPPN-502 (both trade names); YL-6056 manufactured by Japan Epoxy Resin Co., Ltd., YX -4000, YL-6121 (both trade names) and other bixylenol type or biphenol type epoxy resins or EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by Asahi Denka Kogyo Co., Ltd., EXA-1514 manufactured by Dainippon Ink & Chemicals Co., Ltd. (all trade names), etc. Bisphenol S type epoxy resin; Bisphenol A novolac type epoxy resin such as Epicoat 157S (trade name) manufactured by Japan Epoxy Resin Co., Ltd .; Tetraphenylol such as Epicoat YL-931 (trade name) manufactured by Japan Epoxy Resin Co., Ltd. Ethane type epoxy resin; heterocyclic epoxy resin such as TEPIC (trade name) manufactured by Nissan Chemical Co., Ltd .; diglycidyl phthalate resin such as Blemmer DGT (trade name) manufactured by Nippon Oil &Fats; Toto Kasei Co., Ltd. Tetraglycidylxylenoylethane resin such as ZX-1063 (trade name) manufactured by Nippon Steel Chemical Co., Ltd .; ESN-190, ESN- manufactured by Nippon Steel Chemical Co., Ltd. 360, Naphthalene group-containing epoxy resins such as HP-4032, EXA-4750, EXA-4700 (all trade names) manufactured by Dainippon Ink & Chemicals, Inc .; HP-7200 manufactured by Dainippon Ink & Chemicals, Inc. Epoxy resin having a dicyclopentadiene skeleton such as HP-7200H (all trade names); Glycidyl methacrylate copolymer epoxy such as CP-50S and CP-50M (all trade names) manufactured by NOF Corporation Resin; Furthermore, hydantoin type epoxy resin, copolymer epoxy resin of cyclohexyl maleimide and glycidyl methacrylate, alcoholic secondary hydroxyl group obtained by reacting 1,5-dihydroxynaphthalene and bisphenol A type epoxy resin, epihalo Polyfunctional epoxy resin obtained by reacting hydrin (International publication) O 01/024774 discloses), epoxy resins having a 1,3-dioxolane ring obtained ketone by the addition reaction in a part of the epoxy groups.

  Examples of the oxetane resin include 3,7-bis (3-oxetanyl) -5-oxa-nonane, 3,3 ′-(1,3- (2-methylenyl) propanediylbis (oxymethylene)) bis- ( 3-ethyloxetane), 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3- Bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenylbis (3-ethyl-3-oxetanylmethyl) ether, triethylene glycol Bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3 Oxetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3-ethyl-3) -Oxetanylmethoxy) butane, 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ) Ether.

The aforementioned thermosetting components can be used alone or in combination of two or more. These thermosetting components improve characteristics such as resist adhesion and heat resistance by thermosetting with the carboxyl group-containing novolac resin (A). The compounding quantity is sufficient with the ratio of 10 mass parts or more and 100 mass parts or less with respect to 100 mass parts of said carboxyl group containing novolak-type resin (A), Preferably it is a ratio of 15-60 mass parts. When the blending amount of the thermosetting component is less than the above range, the hygroscopicity of the cured film becomes high and the PCT resistance tends to decrease, and the solder heat resistance and electroless plating resistance tend to decrease. On the other hand, when the above range is exceeded, the developability of the coating film and the electroless plating resistance of the cured film are deteriorated, and the PCT resistance is also inferior. For electronic materials, the thermosetting component is preferably an epoxy resin, and among them, a polyfunctional epoxy resin having two or more epoxy groups in one molecule is preferable.

In addition, the curable composition of the present invention contains an organic solvent in order to dissolve the carboxyl group-containing novolac resin (A) and the thermosetting component, and to adjust the composition to a viscosity suitable for the coating method. Can do.
Examples of the organic solvent include aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether , Glycol ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol Monoethyl ether Acetates such as cetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum Examples include petroleum solvents such as ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. These organic solvents can be used alone or as a mixture of two or more. The compounding quantity of the organic solvent can be made into arbitrary quantity according to a use etc.

Furthermore, the curable composition of this invention can mix | blend a thermosetting catalyst. Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzyl Amine compounds such as amine and 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic acid hydrazide and sebacic acid hydrazide; and phosphorus compounds such as triphenylphosphine can be used. Examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Co., Ltd., U-CAT3503N manufactured by San Apro Co., Ltd. U-CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof), and the like. In particular, as long as it is for improving thermosetting properties, it is not limited to these, as long as it is a curing catalyst for a compound having a cyclic ether, or a compound that promotes the reaction between a compound having a cyclic ether and a carboxylic acid, You may use individually or in mixture of 2 or more types . Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2 S-triazine derivatives such as -vinyl-4,6-diamino-S-triazine / isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct can also be used, These compounds are preferably used in combination with the curing catalyst. The amount of the curing catalyst to be blended is a normal quantitative ratio, for example, 0.1 to 20 parts by mass, preferably 0.5 to 15.0 parts per 100 parts by mass of the carboxyl group-containing novolac resin (A). It is a ratio of parts by mass.

The curable composition of the present invention further contains, as necessary, barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, Known or commonly used inorganic fillers such as aluminum hydroxide and mica can be used alone or in combination of two or more. These are used for the purpose of suppressing curing shrinkage of the coating film and improving properties such as adhesion and hardness. The blending amount of the inorganic filler is 10 to 300 parts by mass, preferably 30 to 200 parts by mass with respect to 100 parts by mass of the carboxyl group-containing novolac resin (A).

  Further, the curable composition of the present invention may further include a known and commonly used colorant such as phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, if necessary. Known and commonly used thermal polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol and phenothiazine, known and commonly used thickeners such as fine silica, organic bentonite and montmorillonite, silicones, fluorines, polymers, etc. Known and conventional additives such as a defoaming agent and / or a leveling agent, an imidazole series, a thiazole series, a triazole series silane coupling agent, and the like can be blended.

  Furthermore, the curable composition of this invention can mix | blend flame retardants, such as a halogenated flame retardant, a phosphorus flame retardant, and an antimony flame retardant, for the purpose of obtaining a flame retardance. The compounding quantity of a flame retardant is 1-200 mass parts normally with respect to 100 mass parts of said carboxyl group-containing novolak-type resin (A), Preferably it is 5-50 mass parts. When the blending amount of the flame retardant is in the above range, the flame retardancy, solder heat resistance, and electrical insulation of the composition are highly balanced and suitable.

  Moreover, water can also be added to the curable composition of this invention for the fall of flammability. In the case of adding water, the carboxyl group of the carboxyl group-containing novolak resin (A) is replaced with amines such as trimethylamine and triethylamine, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl. It is preferable to make the curable composition of the present invention conform to water by salt formation with a (meth) acrylate resin having a tertiary amino group such as (meth) acrylamide and acryloylmorpholine.

  The curable composition of this invention can also be made into the form of the dry film provided with the support body and the layer which consists of the said curable composition formed on this support body. Preferably, a peelable cover film is further laminated on the curable composition layer of the film.

  A plastic film is used as the support, and a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, or a polystyrene film is preferably used. Here, the thickness of the support is appropriately selected within a range of 10 to 150 μm.

  The curable composition layer on the support is coated with a uniform thickness on the support with a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater or the like. It is obtained by evaporating the solvent by heating and drying. The thickness of the curable composition layer is not particularly limited and is appropriately selected within a range of 10 to 150 μm.

  Generally, a polyethylene film, a polypropylene film, a Teflon (registered trademark) film, a surface-treated paper, or the like is used as the cover film. The cover film is not limited to a specific one as long as the adhesive strength with the curable composition layer is smaller than the adhesive strength between the curable composition layer and the support.

The curable composition of the present invention is prepared to have a viscosity suitable for the coating method by dilution as necessary. The curable composition having a adjusted viscosity is applied to a printed wiring board formed with a circuit by a method such as a screen printing method, a curtain coating method, a spray coating method, or a roll coating method, for example, at about 60 to 100 ° C. A tack-free coating film can be formed by evaporating and drying the organic solvent contained in the composition.
In the case of a dry film comprising a support and a layer made of the curable composition formed on the support, the dry film is pasted on a printed wiring board formed with a circuit using a hot roll laminator or the like. Match. At this time, a dry film is bonded to the printed wiring board so that the curable composition layer contacts the printed wiring board on which the circuit is formed. Thereby, the coating film of the said curable composition can be formed on the said printed wiring board. In the case of a dry film provided with a peelable cover film on the curable composition layer, after the cover film is peeled off, the curable composition layer and the printed wiring board formed with a circuit are in contact with each other. A dry film and a printed wiring board are bonded together using a hot roll laminator or the like. Thereby, the coating film of the said curable composition can be formed on the printed wiring board by which the circuit was formed.

After the coating film is formed on the printed circuit board on which the circuit is formed, the active energy rays such as laser light are directly irradiated according to the pattern, or the active energy rays are selectively irradiated through the photomask on which the pattern is formed. By exposing, an unexposed part can be developed with dilute alkaline aqueous solution to form a resist pattern. In the case of using the dry film, after selectively exposing without peeling off the support, the support is peeled off and developed.
After the resist pattern is formed, it is further cured by heating, or by heat curing after irradiation with active energy rays, or after heat curing, it is irradiated with active energy rays and finally cured (main curing). By doing so, a cured film (cured product) excellent in electrical insulation, PCT resistance, adhesion, solder heat resistance, chemical resistance, electroless gold plating resistance and the like can be formed.

As the alkaline aqueous solution, alkaline aqueous solutions such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia and amines can be used.
As an irradiation light source for photocuring, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like is appropriate. A laser beam or the like can also be used as an active energy ray.

  EXAMPLES Hereinafter, although an Example etc. are shown and this invention is demonstrated more concretely, this invention is not limited to these Examples. In the following description, “part” means part by mass unless otherwise specified.

Synthesis example 1
203 parts of cresol novolac type epoxy resin YDCN-700-5 (manufactured by Tohto Kasei Co., Ltd., epoxy equivalent: 203) was put in a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and an air blowing tube, and diethylene glycol mono 293 parts of ethyl ether acetate was added and dissolved by heating. Next, 43.2 parts of acrylic acid, 0.2 part of methylhydroquinone and 3 parts of triphenylphosphine were added and reacted at 95 to 105 ° C. for 3 hours while blowing air. Thereafter, 46.4 parts of maleic acid and 0.3 part of methylhydroquinone were added and reacted at 95 to 105 ° C. for 4 hours to obtain a solution having a nonvolatile content of 50%. The carboxyl group-containing novolak resin in the solution thus obtained has an acid value of 78 mgKOH / g and an epoxy equivalent of 9013 g / eq. Met. Hereinafter, this solution is referred to as A-1.

Synthesis example 2
203 parts of cresol novolac type epoxy resin YDCN-700-5 (manufactured by Tohto Kasei Co., Ltd., epoxy equivalent: 203) was put in a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and an air blowing tube, and diethylene glycol mono 305 parts of ethyl ether acetate was added and dissolved by heating. Next, 43.2 acrylic acid, 0.2 part of methylhydroquinone and 3 parts of triphenylphosphine were added and reacted at 95 to 105 ° C. for 3 hours while blowing air. Thereafter, 66.4 parts of phthalic acid and 0.3 part of methylhydroquinone were added and reacted at 95 to 105 ° C. for 4 hours to obtain a solution having a nonvolatile content of 51%. The carboxyl group-containing novolak resin in the solution thus obtained has an acid value of 72 mgKOH / g and an epoxy equivalent of 6744 g / eq. Met. Hereinafter, this solution is referred to as A-2.

Synthesis example 3
203 parts of cresol novolac type epoxy resin YDCN-700-5 (manufactured by Tohto Kasei Co., Ltd., epoxy equivalent: 203) was put in a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and an air blowing tube, and diethylene glycol mono 292 parts of ethyl ether acetate was added and dissolved by heating. Next, 36 parts of acrylic acid, 0.2 part of methylhydroquinone and 3 parts of triphenylphosphine were added and reacted at 95 to 105 ° C. for 3 hours while blowing air. Thereafter, 46.4 parts of maleic acid and 0.3 part of methylhydroquinone were added and the mixture was reacted at 95 to 105 ° C. for 2 hours, and further 6 parts of acetic acid was added and reacted at 95 to 105 ° C. for 4 hours to obtain a solution having a nonvolatile content of 50%. . The carboxyl group-containing novolac resin in the solution thus obtained has an acid value of 77 mgKOH / g and an epoxy equivalent of 5194 g / eq. Met. Hereinafter, this solution is referred to as A-3.

Synthesis example 4
Instead of 6 parts of acetic acid in Synthesis Example 3, 7.2 parts of acrylic acid was used and reacted in the same manner as in Synthesis Example 3 to obtain a solution having a nonvolatile content of 50%. The carboxyl group-containing novolak resin in the solution thus obtained has an acid value of 79 mgKOH / g and an epoxy equivalent of 5530 g / eq. Met. Hereinafter, this solution is referred to as A-4.

Synthesis example 5
203 parts of cresol novolac type epoxy resin YDCN-700-5 (manufactured by Tohto Kasei Co., Ltd., epoxy equivalent: 203) was put in a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and an air blowing tube, and diethylene glycol mono 291 parts of ethyl ether acetate was added and dissolved by heating. Next, 36 parts of acrylic acid, 6 parts of acetic acid, 0.2 part of methylhydroquinone and 3 parts of triphenylphosphine were added and reacted at 95 to 105 ° C. for 3 hours while blowing air. Thereafter, 46.4 parts of maleic acid and 0.3 part of methylhydroquinone were added and reacted at 95 to 105 ° C. for 4 hours to obtain a solution having a nonvolatile content of 50%. The carboxyl group-containing novolak resin in the solution thus obtained has an acid value of 77 mgKOH / g and an epoxy equivalent of 7911 g / eq. Met. Hereinafter, this solution is referred to as A-5.

Comparative Synthesis Example 1
Cresol novolac type epoxy resin Epicron N-695 (Dainippon Ink Chemical Co., Ltd., epoxy equivalent: 220) 220 parts was put in a reaction vessel equipped with a thermometer, stirrer, reflux condenser and air blowing tube, 220 parts of diethylene glycol monoethyl ether acetate was added and dissolved by heating. Next, 0.46 parts of methylhydroquinone and 3.0 parts of triphenylphosphine were added. This mixture was heated to 95 to 105 ° C., 72 parts of acrylic acid was gradually added dropwise, and reacted for 4 hours while blowing air. The reaction product was cooled to 80 to 90 ° C., 106 parts of tetrahydrophthalic anhydride was added and reacted for 5 hours to obtain a solution having a nonvolatile content of 65%. The carboxyl group-containing novolak resin in the solution thus obtained had an acid value of 100 mgKOH / g. Hereinafter, this solution is referred to as B-1.

Comparative Synthesis Example 2
In a reaction vessel equipped with a gas introduction tube, a stirring device, a cooling tube, a thermometer, and a dropping funnel for continuous dropping of an alkali metal hydroxide aqueous solution, a phenolic hydroxyl group equivalent of 80 g / eq. 224 parts of 1,5-dihydroxynaphthalene and 1075 parts of bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., Epicoat 828, epoxy equivalent 189 g / eq.) Were added at 110 ° C. with stirring in a nitrogen atmosphere. Dissolved. Thereafter, 0.65 part of triphenylphosphine was added, the temperature in the reaction vessel was raised to 150 ° C., the reaction was continued for about 90 minutes while maintaining the temperature at 150 ° C., and an epoxy resin having an epoxy equivalent of 452 g / equivalent ( a) was obtained. Next, the temperature in the flask was cooled to 40 ° C., 1920 parts of epichlorohydrin, 1690 parts of toluene, and 70 parts of tetramethylammonium bromide were added, and the temperature was raised to 45 ° C. and maintained with stirring. Thereafter, 364 parts of a 48 wt% aqueous sodium hydroxide solution were continuously added dropwise over 60 minutes, and then reacted for another 6 hours. After completion of the reaction, excess epichlorohydrin and most of toluene were recovered by distillation under reduced pressure, and the reaction product containing by-product salt and toluene was dissolved in methyl isobutyl ketone and washed with water. After the organic solvent layer and the aqueous layer were separated, methyl isobutyl ketone was distilled off from the organic solvent layer under reduced pressure to obtain an epoxy equivalent of 277 g / eq. The polynuclear epoxy resin (b) was obtained. When the obtained polynuclear epoxy resin (b) is calculated from the epoxy equivalent, about 1.59 of 1.98 alcoholic hydroxyl groups in the epoxy resin (a) are epoxidized. Therefore, the epoxidation rate of the alcoholic hydroxyl group is about 80%. Next, 277 parts of the polynuclear epoxy resin (b) is placed in a flask equipped with a stirrer, a cooling tube and a thermometer, 290 parts of propylene glycol monomethyl ether acetate is added, and dissolved by heating, 0.46 part of methyl hydroquinone, 1.38 parts of phenylphosphine was added, heated to 95 to 105 ° C., 72 parts of acrylic acid was gradually added dropwise, and reacted for 4 hours while blowing air. The reaction product was cooled to 80 to 90 ° C., 129 parts of tetrahydrophthalic anhydride was added and reacted for 5 hours to obtain a solution having a nonvolatile content of 62%. The carboxyl group-containing resin in the solution thus obtained had an acid value of 100 mgKOH / g. Hereinafter, this solution is referred to as B-2.

Comparative Synthesis Example 3
To an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device and a stirring device, a novolac type cresol resin (trade name “Shonol CRG951” manufactured by Showa Polymer Co., Ltd., phenolic hydroxyl group equivalent: 119.4 g / eq) .) 119.4 parts, 1.19 parts of potassium hydroxide, and 119.4 parts of toluene were charged, and the system was purged with nitrogen while stirring and heated. Next, 63.8 parts of propylene oxide was gradually added dropwise and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Thereafter, the reaction solution was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The nonvolatile content was 62.1% and the alcoholic hydroxyl group equivalent was 182.2 g / eq. A novolak-type cresol resin propylene oxide reaction solution was obtained. This was an average of about 1.08 mole of alkylene oxide added per equivalent of phenolic hydroxyl group. 293.0 parts of a propylene oxide reaction solution of the obtained novolac-type cresol resin, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 part of methylhydroquinone, and 252.9 parts of toluene were mixed with a stirrer and a temperature. A reaction vessel equipped with a total and an air blowing tube was charged, air was blown at a rate of 10 ml / min, and the reaction was carried out at 110 ° C. for 12 hours while stirring. 12.6 parts of water was distilled from the water produced by the reaction as an azeotrope with toluene. Thereafter, the reaction solution was cooled to room temperature, neutralized with 35.35 parts of a 15% aqueous sodium hydroxide solution, and then washed with water. Thereafter, toluene was distilled off while substituting 149 parts of propylene glycol monomethyl ether acetate with an evaporator to obtain a novolak acrylate resin solution. Next, 332.5 parts of the obtained novolak acrylate resin solution and 1.22 parts of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer, and an air blowing tube, and air was supplied at a rate of 10 ml / min. While blowing and stirring, 60.8 parts of tetrahydrophthalic anhydride was gradually added and reacted at 95 to 101 ° C. for 6 hours to obtain a solution having a nonvolatile content of 65%. The carboxyl group-containing novolac resin in the solution thus obtained had an acid value of 84 mgKOH / g. Hereinafter, this solution is referred to as B-3.

Evaluation of curable composition (1) Developability The solutions obtained in Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 3 were blended in accordance with the components and blending compositions (numerical values are parts by mass) shown in Table 1, respectively. Each curable composition was prepared by kneading separately with a three-roll mill. In Table 1, Irgacure 907 is a polymerization initiator, and DPHA is a photosensitive acrylate compound.

次に、前記硬化性組成物を、スクリーン印刷法により、１００メッシュのポリエステルスクリーンを用いて３０〜４０μｍの厚さになるように、パターン形成されている銅スルホールプリント配線基板に全面塗布し、塗膜を８０℃の熱風乾燥器を用いて２０分間乾燥した。その後、１ｗｔ％炭酸ナトリウム水溶液で２０秒間、２．０ｋｇ／ｃｍ^２のスプレー圧で現像し、現像後の塗膜の状態を目視判定した。判定基準は次の通りである。
○：塗膜が除去された。
×：現像されない部分があった。
判定結果を表２に記す。

Next, the curable composition is applied on the entire surface of a patterned copper through-hole printed wiring board by a screen printing method so as to have a thickness of 30 to 40 μm using a 100 mesh polyester screen. The membrane was dried for 20 minutes using a hot air dryer at 80 ° C. Then, it developed with the spray pressure of 2.0 kg / cm < ² > for 20 second with 1 wt% sodium carbonate aqueous solution, and the state of the coating film after image development was judged visually. Judgment criteria are as follows.
○: The coating film was removed.
X: There was a portion that was not developed.
The determination results are shown in Table 2.

For each curable composition, (2) pencil hardness, (3) solder heat resistance, (4) acid resistance, (5) alkali resistance, (6), adhesion, (7) PCT resistance, (8) Performance tests were conducted on electroless gold plating resistance, (9) whitening resistance, (10) electrical insulation, and (11) flexibility. The test results are shown in Table 3.

The evaluation method for each performance test is as follows.
(2) Pencil hardness A pattern so that each of the curable compositions of Composition Examples 1 to 5 and Comparative Composition Examples 1 to 3 has a thickness of 50 to 60 μm using a 100 mesh polyester screen by screen printing. The entire surface of the copper through-hole printed wiring board is applied, and the coating film is dried for 30 minutes in a hot air circulation drying oven at 80 ° C., and a negative film having a resist pattern is adhered to the coating film. Ultraviolet rays were irradiated using a model HMW-680GW manufactured by Oak Manufacturing Co., Ltd. (exposure amount 600 mJ / cm 2). Subsequently, development was performed with a 1% aqueous sodium carbonate solution for 60 seconds at a spray pressure of 2.0 kg / cm 2 to dissolve and remove unexposed portions. Thereafter, heat curing was performed for 60 minutes in a hot air circulation drying oven at 150 ° C., and the pencil hardness test was performed on the evaluation substrate having the obtained cured film in accordance with JIS K 5400.

(3) Heat resistance According to the test method of JIS C 6481, the said evaluation board | substrate was immersed in a 260 degreeC solder bath for 10 second 3 times, and the change of the external appearance was evaluated on the following references | standards. As the post flux (rosin type), a flux according to JIS C 6481 was used.
○: No change in appearance △: Discoloration of the cured film is observed ×: Hardened film is lifted, peeled off, or soldered

(4) Acid resistance The said evaluation board | substrate was taken out after 30-minute immersion at 10 degreeC sulfuric acid aqueous solution for 30 minutes, and the state and adhesiveness of the cured film were comprehensively evaluated. The judgment criteria are as follows.
○: No change is observed Δ: Only a slight change ×: The coating has blisters or swelling drops

(5) Alkali resistance A test similar to the acid resistance test was conducted on the evaluation substrate, except that the 10 volume% sulfuric acid aqueous solution was changed to a 10 volume% sodium hydroxide aqueous solution, and evaluation was performed.

(6) Adhesiveness According to the test method of JIS D 0202, the evaluation board | substrate was cross-cut into a grid shape, and then the state of peeling after the peeling test with a cellophane adhesive tape was visually determined. Judgment criteria are as follows.
○: 100/100
Δ: 50/100 to 90/100
X: 0/100 to 50/100

(7) PCT resistance The PCT resistance of the cured film of the evaluation substrate was evaluated under the following criteria under the conditions of 121 ° C. and 50 hours in saturated steam.
○: The cured film does not blister, peel off or discolor.
Δ: The cured film has some swelling, peeling, and discoloration.
X: The cured film has blistering, peeling and discoloration.

(8) Resistance to electroless gold plating The evaluation substrate was subjected to electroless nickel plating and then electroless gold plating, and a change in appearance and a peeling test using a cellophane adhesive tape were performed to determine the peeled state of the cured film. Judgment criteria are as follows.
○: No change in appearance and no peeling of the cured film.
(Triangle | delta): Although there is no change of an external appearance, there exists slight peeling in a cured film.
X: Lifting of the cured film is observed, plating stagnation is observed, and peeling of the cured film is large in the peeling test.

(9) Whitening resistance After the said evaluation board | substrate was immersed in 60 degreeC hot water for 10 minutes and taken out, the surface state of the cured film when naturally cooled to room temperature was evaluated on the following references | standards.
○: No change in appearance.
Δ: Appearance is slightly white and cloudy.
X: The appearance is white and cloudy.

(10) Electrical insulation In place of the copper through-hole printed wiring board on which the pattern is formed, the B pattern of the printed circuit board (thickness 1.6 mm) defined by the IPC is used, and the curable composition is formed by the above method. The product was applied and cured, and the electrical insulation of the resulting cured film was evaluated under the following conditions and criteria.
Humidification conditions: temperature 121 ° C., humidity 85% RH, applied voltage 5 V, 100 hours.
Measurement conditions: measurement time 60 seconds, applied voltage 500V.
○: Insulation resistance value after humidification of 10 ⁹ Ω or more, no copper migration.
Δ: Insulation resistance value after humidification of 10 ⁹ Ω or more, copper migration.
X: Insulation resistance value after humidification of 10 ⁸ Ω or less, copper migration.

(11) Flexibility A polyester film is used in place of the patterned copper through-hole printed wiring board, and the curable resin composition is applied and cured by the above method, and then the cured coating film is formed from the polyester film. And an evaluation film having a length of 5 cm and a width of 2 cm was obtained. The obtained film was bent and evaluated according to the following criteria.
○: The film was bent by 170 ° and not cracked.
(Triangle | delta): When a film is bend | folded 170 degree | times, it cracks, but it is a 160 degree bend | fold and was not cracked.
X: The film was bent by 160 ° and cracked.

  Since the curable composition of the present invention as described above is excellent in developability and obtains a cured product excellent in various properties as described above, a solder resist, a dry film, an etching resist, a plating resist, a multilayer wiring It is useful for applications such as an interlayer insulating layer of a plate, a permanent mask used in the manufacture of a tape carrier package, a resist for a flexible wiring board, a resist for a color filter, an ink resist, and the like.

Claims (10)

(A) It consists of structural units represented by the following general formulas (1), (2), (3) and (4), an acid value of 20 to 131 mgKOH / g, and an epoxy equivalent of 3000 g / eq. A carboxyl group-containing novolak resin characterized by being soluble in an organic solvent as described above

Wherein R _{1 to} R ₄ are each a hydrogen atom or a methyl group, X ₁ and X ₂ are the same or different monocarboxylic acid residues, Y is a dicarboxylic acid residue, and n1 to n3 are the same or different integers. N4 represents an integer of 0 or more).
A curable composition capable of alkali development, comprising (B) a photosensitive (meth) acrylate compound, and (C) a photopolymerization initiator. _2. The curable composition according to claim 1, wherein in the general formulas (1) and (2), X ₁ and X ₂ are each an unsaturated group-containing monocarboxylic acid residue. The curable composition according to claim 1, wherein, in the general formulas (1) and (2), X ₁ is an unsaturated group-containing monocarboxylic acid residue, and X ₂ is a monocarboxylic acid residue not containing an unsaturated group. object.   The same or different unsaturated group-containing monocarboxylic acids (b) and (b ′) are partially added to the epoxy group of the novolak-type epoxy resin (a), and the epoxy group of the resulting reaction product (c) is obtained. The curable composition according to claim 1, obtained by addition reaction of dicarboxylic acid (d).   An unsaturated group-containing monocarboxylic acid (b) is partially added to the epoxy group of the novolak-type epoxy resin (a), and the epoxy group of the resulting reaction product (c ′) is converted to a dicarboxylic acid (d). The curable composition according to claim 1, which is obtained by partially subjecting an addition reaction of the unsaturated group-containing monocarboxylic acid (b ') to the epoxy group of the reaction product (e) obtained. object.   An unsaturated group-containing monocarboxylic acid (b) is partially added to the epoxy group of the novolak-type epoxy resin (a), and the epoxy group of the resulting reaction product (c ′) is converted to a dicarboxylic acid (d). The curable product according to claim 1, which is obtained by subjecting a partial addition reaction to an epoxy group of the reaction product (e) obtained and a monocarboxylic acid (f) containing no unsaturated group. Composition.   An unsaturated group-containing monocarboxylic acid (b) and a monocarboxylic acid (f) not containing an unsaturated group are partially added to the epoxy group of the novolak-type epoxy resin (a), and the reaction product ( The curable composition according to claim 1, which is obtained by subjecting the epoxy group of g) to an addition reaction of dicarboxylic acid (d). The curable composition according to any one of claims 4 to 7, wherein the unsaturated group-containing monocarboxylic acid (b) is acrylic acid or methacrylic acid.   The curable composition according to any one of claims 4 to 8, wherein the dicarboxylic acid (d) is a carboxylic acid that is soluble in a reaction solvent and / or melts in the solvent at a reaction temperature.   Hardened | cured material of the curable composition in any one of Claims 1-9.