JP2010024336A - Alkali developable curable composition, and cured material of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable composition capable of forming a cured film excellent in developing property and also characteristics such as hardness, solder heat resistance, chemical resistance, cohesiveness, PCT (pressure cocker test) resistance, non-electrolytic gilding resistance, whitening resistance, electric insulation, flexibility, etc., and also to provide a cured material of the same. <P>SOLUTION: The alkali developable curable composition contains (A) a carboxyl group-containing novolac type resin consisting of specific 4 chemical structural units, having a ≥3,000 g/eq. epoxy equivalent and soluble to an organic solvent, (B) a carboxyl group-containing compound, (C) a photosensitive (meth)acrylate compound and (D) a photopolymerization initiator. <P>COPYRIGHT: (C)2010,JPO&INPIT

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. For example, a curable composition using a curable resin in which an acid anhydride is added to a reaction product of a novolak type epoxy resin and an unsaturated group-containing monocarboxylic acid (see Patent Document 1), two glycidyl groups in one molecule An epihalohydrin is reacted with an alcoholic secondary hydroxyl group obtained by reacting an aromatic epoxy resin having a hydroxyl group with an aromatic alcohol resin having two phenolic hydroxyl groups in one molecule. Examples thereof include a curable composition using a curable resin to which a saturated group-containing monocarboxylic acid and then an acid anhydride are added (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 become denser as electronic devices become lighter, thinner, and shorter, and in response to this, higher performance of solder resist is required. That is, when manufacturing a high-density printed wiring board, the curable composition that is commercially available in the past does not have sufficient developability, and lacks the resolution corresponding to the higher density. 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 method for solving the problem of flexibility, the alcoholic secondary hydroxyl group of the bisphenol A type epoxy resin is reacted with epihalohydrin, and the resulting polyfunctional epoxy resin is subjected to 0.2 to 0.2 equivalent per epoxy equivalent. Carboxyl group-containing photosensitivity obtained by reacting 1.2 mol of ethylenically unsaturated carboxylic acid and further reacting 0.2 to 1.0 mol of polybasic carboxylic acid and / or its anhydride per epoxy equivalent. A curable composition using a 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, the curable composition does not have sufficient developability corresponding to the increase in the density of printed wiring boards accompanying the recent reduction in thickness and size of electronic devices.

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. An object of the present invention is to provide a curable composition capable of forming a cured film having excellent properties such as plating 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を表わす。）、
（Ｂ）カルボキシル基含有化合物、
（Ｃ）感光性（メタ）アクリレート化合物、及び
（Ｄ）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 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, and Y is a dicarboxylic acid residue).
(B) a carboxyl group-containing compound,
It contains (C) a photosensitive (meth) acrylate compound, and (D) 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 X ₁ and X _{2 in the} general formulas (1) and (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 not containing 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 the same as the epoxy group of the novolac epoxy resin (a), Different unsaturated group-containing monocarboxylic acid (b) and unsaturated group-containing monocarboxylic acid (b ′) are partially subjected to addition reaction, and the epoxy group of the obtained reaction product (c) is converted to dicarboxylic acid (d). Or an epoxy group of the novolak type epoxy resin (a) is 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, a carboxylic acid the dicarboxylic acid (d) is soluble in the solvent soluble and / or the reaction temperature in the reaction solvent is 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 composition containing a resin and a carboxyl group-containing compound has excellent developability and excellent hardness, solder heat resistance, chemical resistance, adhesion, PCT resistance, electroless gold plating resistance, whitening resistance, electrical insulation, good The present inventors have found that a cured product having flexibility is provided, and have completed the present invention.

  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 carboxyl groups are located at the ends of the side chains, respectively, so the reactivity is excellent, and the composition obtained by adding a carboxyl group-containing compound, a photosensitive (meth) acrylate compound, and a photopolymerization initiator to this resin has a crosslinking density. Gives a cured product with high and excellent properties.

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, the 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 then the reaction product ( ch) the remaining epoxy group is subjected to an addition reaction of dicarboxylic acid (d) (hereinafter, the structure obtained by this method is referred to as K), and the epoxy group of the novolac type epoxy resin (a) is partially mixed with Carboxylic 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 dicarboxylic acid (d), and further obtained reaction product (ei) The remaining epoxy group is subjected to an addition reaction of a monocarboxylic acid (b′f) (hereinafter, the structure obtained by this method is referred to as “N”). Used is readily carried out in a solvent or without a solvent.

  In order to obtain the structure K, the epoxy group of the novolak-type epoxy resin (a) is partially reacted with a monocarboxylic acid (bf) and the same or different monocarboxylic acid (b′f). A product (ch) is obtained, in which case the reaction is preferably carried out 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 not containing an unsaturated group 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, sodium, etc. 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 equivalent. 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. One or more of them can be used. Preference is given here to dicarboxylic acids (d) which are soluble in the reaction solvent and / or melt in the solvent at the reaction temperature, preferably malonic acid, glutaric acid, 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 (A) is preferably 20 to 131 mgKOH / g, more 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.

  Next, the carboxyl group-containing compound (B) is a compound having at least one, preferably two or more carboxyl groups in one molecule. Specifically, both a carboxyl group-containing compound that itself does not have an ethylenically unsaturated double bond and a carboxyl group-containing photosensitive compound that has an ethylenically unsaturated double bond can be used. Although not limited to these, the compounds listed below can be particularly preferably used.

(1) a carboxyl group-containing compound obtained by copolymerizing an unsaturated carboxylic acid and a compound having an unsaturated double bond,
(2) a carboxyl group-containing photosensitive compound obtained by adding an ethylenically unsaturated group as a pendant to a copolymer of an unsaturated carboxylic acid and a compound having an unsaturated double bond,
(3) A copolymer of an epoxy group, a compound having an unsaturated double bond and a compound having an unsaturated double bond is reacted with an unsaturated carboxylic acid, and the resulting secondary hydroxyl group is saturated or unsaturated polybasic. A carboxyl group-containing photosensitive compound obtained by reacting an acid anhydride,
(4) A carboxyl group-containing photosensitive compound obtained by reacting a copolymer of an acid anhydride having an unsaturated double bond and a compound having an unsaturated double bond with a compound having a hydroxyl group and an unsaturated double bond. ,
(5) An esterification reaction of an epoxy group of a polyfunctional epoxy compound having at least two epoxy groups in one molecule and a carboxyl group of an unsaturated monocarboxylic acid, and the resulting hydroxyl group is further saturated or unsaturated polybasic acid anhydride Carboxyl group-containing photosensitive compound obtained by reacting a product,
(6) Reaction of an organic acid having one carboxyl group in one molecule and not having an ethylenically unsaturated bond with the epoxy group of a copolymer of a compound having an unsaturated double bond and glycidyl (meth) acrylate A carboxyl group-containing compound obtained by reacting the produced secondary hydroxyl group with a saturated or unsaturated polybasic acid anhydride,
(7) a carboxyl group-containing compound obtained by reacting a hydroxyl group-containing polymer with a saturated or unsaturated polybasic acid anhydride,
(8) A carboxyl group-containing photosensitivity obtained by further reacting a carboxyl group-containing compound obtained by reacting a hydroxyl group-containing polymer with a saturated or unsaturated polybasic acid anhydride and a compound having an epoxy group and an unsaturated double bond. Sex compounds,
(9) A polyfunctional epoxy compound having at least two epoxy groups in one molecule, an unsaturated monocarboxylic acid, at least two hydroxyl groups in one molecule, and one hydroxyl group that reacts with an epoxy group A carboxyl group-containing photosensitive compound obtained by reacting a reaction product with a compound having another reactive group with a saturated or unsaturated polybasic acid anhydride,
(10) One polyfunctional epoxy compound having at least two epoxy groups in one molecule, unsaturated monocarboxylic acid, at least two hydroxyl groups in one molecule, and one hydroxyl group that reacts with an epoxy group An unsaturated group-containing polycarboxylic acid urethane compound comprising a reaction product of a compound having another reactive group, a reaction product of a saturated or unsaturated polybasic acid anhydride and an unsaturated group-containing monoisocyanate,
(11) A polyfunctional oxetane compound having at least two oxetane rings in one molecule is reacted with an unsaturated monocarboxylic acid, and a saturated or unsaturated polybasic acid anhydride with respect to the primary hydroxyl group in the resulting modified oxetane compound Carboxyl group-containing photosensitive compound obtained by reacting a product,
(12) A carboxyl group-containing photosensitive compound obtained by introducing an unsaturated double bond into a reaction product of a bisepoxy compound and a dicarboxylic acid and subsequently reacting with a saturated or unsaturated polybasic acid anhydride,
(13) A carboxyl group-containing photosensitive compound obtained by introducing an unsaturated double bond into a reaction product of a bisepoxy compound and a bisphenol and subsequently reacting with a saturated or unsaturated polybasic acid anhydride, and ( 14) obtained by reacting a reaction product of a novolak type phenolic resin with an alkylene oxide and / or a cyclic carbonate with an unsaturated monocarboxylic acid, and reacting the resulting reaction product with a saturated or unsaturated polybasic acid anhydride. Carboxyl group-containing photosensitive compound.

  The mixing ratio of the carboxyl group-containing novolac resin (A) and the carboxyl group-containing compound (B) is preferably A: B = 20: 80 to 80:20 by mass ratio, more preferably A: B = 30. : 70-70: 30. If the ratio is outside the range of A: B = 20: 80 to 80:20, sufficient characteristics may not be obtained. The acid value of the carboxyl group-containing novolak resin (A) and the carboxyl group-containing compound (B) is 20 to 200 mgKOH / g, preferably 33 to 150 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 (C) 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 novolak 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 mixture of the carboxyl group-containing novolac resin (A) and the carboxyl group-containing compound (B). 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 (C) is preferably 100 parts by mass or less with respect to 100 parts by mass of the mixture of the carboxyl group-containing novolac resin (A) and the carboxyl group-containing compound (B). 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 (D) 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 a (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 of mixtures of the said carboxyl group-containing novolak-type resin (A) and a carboxyl group-containing compound (B).

  Moreover, the curable composition of this invention can mix | blend a thermosetting component in order to accelerate | stimulate the thermosetting of a carboxyl group-containing novolak-type resin (A) and a carboxyl group-containing compound (B). Any substance may be used as long as it reacts with the carboxyl group of the carboxyl group-containing novolac resin (A) and the carboxyl group-containing compound (B) by heat. Generally, an epoxy resin, an oxetane resin, etc. are mentioned.

Examples of the epoxy resin include Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1004, Epicron 840, Epicron 850, Epicron 1050, Epicron 1050, and Epitome 2055 manufactured by Dainippon Ink & Chemicals, Inc. 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. Tetraglycidyl xylenoylethane resin such as ZX-1063 (trade name) manufactured by Nippon Steel Chemical Co., Ltd .; ESN-190, ESN- 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 above 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 the mixture of the carboxyl group-containing novolac resin (A) and the carboxyl group-containing compound (B). The blending amount is sufficient in a ratio of 10 parts by mass to 100 parts by mass with respect to 100 parts by mass of the mixture of the carboxyl group-containing novolac resin (A) and the carboxyl group-containing compound (B), preferably 15 It is a ratio of -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.

  Further, the curable composition of the present invention dissolves the carboxyl group-containing novolac resin (A), the carboxyl group-containing compound (B) and the thermosetting component, and adjusts the composition to a viscosity suitable for the coating method. In addition, an organic solvent can be blended.

  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.

  Moreover, 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. Particularly, in order to improve the thermosetting characteristics, 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 of 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 is sufficient in a normal quantitative ratio, for example, 0.1 to 20 parts by mass with respect to 100 parts by mass of the mixture of the carboxyl group-containing novolac resin (A) and the carboxyl group-containing compound (B). The ratio is preferably 0.5 to 15.0 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 inorganic fillers 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 amount of the flame retardant is usually 1 to 200 parts by mass, preferably 5 to 50 parts by mass with respect to 100 parts by mass of the mixture of the carboxyl group-containing novolac resin (A) and the carboxyl group-containing compound (B). . 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. The thickness of the support is appropriately selected in the 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, etc. It is obtained by evaporating the solvent by heating and drying. Although there is no restriction | limiting in particular about the thickness of a curable composition layer, It selects suitably in the range of 10-150 micrometers.

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

  The curable composition of the present invention having the above composition is diluted as necessary to adjust the viscosity to be suitable for the coating method. For example, this is applied to a printed wiring board on which a circuit is formed by a method such as a screen printing method, a curtain coating method, a spray coating method, a roll coating method, etc., and an organic contained in the composition at a temperature of about 60 to 100 ° C. A tack-free coating film can be formed by evaporating and drying the solvent. Moreover, in the case of 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, it bonds together using a hot roll laminator etc. to the printed wiring board by which the circuit was formed ( By bonding the curable composition layer and the printed wiring board on which the circuit is formed, the coating film can be formed on the printed wiring board on which the circuit is formed. In the case of a dry film provided with a peelable cover film on the curable composition layer of the film, after the cover film is peeled off, the curable composition layer and the printed wiring board on which the circuit is formed contact. Thus, it is possible to form a coating film on a printed wiring board on which a circuit is formed by laminating using a hot roll laminator or the like.

  After forming a coating film on a printed wiring board on which a circuit is formed (if the dry film is used, the support is not peeled off), and then directly irradiating active energy rays such as laser light as a pattern or pattern The resist pattern can be formed by selectively exposing with an active energy ray through a photomask on which the film is formed, and developing the unexposed portion with a dilute alkaline aqueous solution (if the above dry film is used, the support is peeled off and developed) To do). Thereafter, only by heat curing, or by heat curing after irradiation of active energy rays or final curing (main curing) by irradiation of active energy rays after heat curing, electrical insulation, PCT resistance, adhesion, solder heat resistance, A cured film (cured product) excellent in chemical resistance, electroless gold plating resistance and the like is 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.
Further, 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 and the like are suitable. In addition, laser beams can be used as active energy rays.

  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 solution of the carboxyl group-containing novolak resin thus obtained had 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 solution of the carboxyl group-containing novolak resin 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 solution of the carboxyl group-containing novolak resin 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 solution of the carboxyl group-containing novolak resin 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 solution of the carboxyl group-containing novolac resin 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.

Synthesis Example 6
483 parts of Epicoat 1001 (epoxy equivalent: 483, manufactured by Japan Epoxy Resin Co., Ltd.) of bisphenol A type epoxy resin is placed in a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and an air blowing tube, and diethylene glycol monoethyl ether 238 parts of acetate was added and dissolved by heating. Next, 72 parts of acrylic acid, 0.2 part of methylhydroquinone and 3 parts of triphenylphosphine were added and reacted at 95 to 105 ° C. for 6 hours while blowing air. Thereafter, 107 parts of tetrahydrophthalic anhydride and 0.3 part of methylhydroquinone were added and reacted at 90 to 100 ° C. for 7 hours, and 424 parts of diethylene glycol monoethyl ether acetate was added to obtain a solution having a nonvolatile content of 50%. The solution of the carboxyl group-containing resin thus obtained had an acid value of 60 mgKOH / g. Hereinafter, this solution is referred to as A-6.

Synthesis example 7
Copolymer solution of glycidyl methacrylate, methyl methacrylate, t-butyl acrylate, 2-ethylhexyl methacrylate and t-butyl methacrylate (diethylene glycol monoethyl ether acetate, non-volatile content 50%, weight average molecular weight 5836, solid content epoxy equivalent: 214 g / eq.) 428 parts, 72 parts of acrylic acid, 0.2 part of methylhydroquinone and 1 part of triphenylphosphine were put into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and an air blowing tube, and 95 while blowing air. The reaction was carried out at ˜105 ° C. for 8 hours. Thereafter, 55 parts of tetrahydrophthalic anhydride and 0.2 part of methylhydroquinone were added and reacted at 95 to 105 ° C. for 9 hours, and 127 parts of diethylene glycol monoethyl ether acetate was added to obtain a solution having a nonvolatile content of 50%. The solution of the carboxyl group-containing resin thus obtained had an acid value of 60 mgKOH / g. Hereinafter, this solution is referred to as A-7.

Synthesis example 8
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 solution of the carboxyl group-containing resin thus obtained had an acid value of 100 mgKOH / g. Hereinafter, this solution is referred to as A-8.

Evaluation of curable composition (1) Developability Each of the solutions obtained in Synthesis Examples 1 to 8 was blended according to the components and blending compositions (numerical values are parts by mass) shown in Table 1, and each of the three roll mills. Each curable composition was prepared by kneading separately. In Table 1, Irgacure 907 is a polymerization initiator, and DPHA is a photosensitive acrylate compound.

Next, this is applied to the entire surface of the copper through-hole printed wiring board on which the pattern is formed by a screen printing method so as to have a thickness of 30 to 40 μm using a 100 mesh polyester screen. It dried for 20 minutes using the hot air dryer, and developed with the spray pressure of 2.0 kg / cm < ² > for 20 second by 1 wt% sodium carbonate aqueous solution, and the state 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 5 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 vol% sulfuric acid aqueous solution was changed to a 10 vol% sodium hydroxide aqueous solution, and the test 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. Application | coating and hardening of the thing were performed and the electrical insulation of the obtained cured film was evaluated in accordance with the following 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.
Δ: The film was cracked when it was folded 170 °, but it was not cracked when it was folded 160 °. X: The film was cracked when it was folded 160 °.

  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 board, a permanent mask used for manufacturing a tape carrier package, a resist for a flexible wiring board, a resist for a color filter, a resist for ink jet, a resist for fiber processing.

Claims (12)

(A) It consists of structural units represented by the following general formulas (1), (2), (3) and (4), and has an epoxy equivalent of 3000 g / eq. A carboxyl group-containing novolac resin characterized by being soluble in an organic solvent.

(Wherein R _{1 to} R ₄ each represent a hydrogen atom or a methyl group, X ₁ and X ₂ represent the same or different monocarboxylic acid residues, and Y represents a dicarboxylic acid residue).
(B) a carboxyl group-containing compound,
A curable composition capable of alkali development, comprising (C) a photosensitive (meth) acrylate compound, and (D) 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. _2. The curable composition according to claim 1, wherein in the general formulas (1) and (2), X ₁ and X ₂ are each a monocarboxylic acid residue not containing an unsaturated group.   Reaction product obtained by partially adding the same or different unsaturated group-containing monocarboxylic acid (b) and unsaturated group-containing monocarboxylic acid (b ′) to the epoxy group of the novolak type epoxy resin (a) The curable composition of Claim 2 obtained by carrying out addition reaction of dicarboxylic acid (d) to the epoxy group of the thing (c).   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 2, wherein the curable composition 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 3, which is obtained by partially subjecting the product to addition reaction, and further adding the monocarboxylic acid (f) containing no unsaturated group to the epoxy group of the obtained reaction product (e). Composition.   The epoxy group of the novolak-type epoxy resin (a) is partially subjected to addition reaction of the unsaturated group-containing monocarboxylic acid (b) and the unsaturated group-free monocarboxylic acid (f), and then the reaction product obtained. The curable composition according to claim 3, obtained by addition reaction of the dicarboxylic acid (d) with the epoxy group of (g).   A monocarboxylic acid (f) not containing an unsaturated group is partially added to the epoxy group of the novolak-type epoxy resin (a), and the epoxy group of the obtained reaction product (h) is converted to a dicarboxylic acid (d The curable composition according to claim 3, 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 (i) obtained. object.   The curable composition according to any one of claims 5 to 9, wherein the unsaturated group-containing monocarboxylic acid (b) is acrylic acid or methacrylic acid.   The curable composition according to any one of claims 5 to 10, 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 which consists of a curable composition in any one of Claims 1-11.