JP2007328028A - Photosensitive resin composition and cured product of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cured product of photosensitive resin composition that is superior in photosensitivity and heat stability, and a cured product of the photosensitive resin composition that is superior in flame retardancy, flexibility, adhesion, pencil hardness, solvent resistance, acid resistance, heat resistance, gold-plating resistance. <P>SOLUTION: The photosensitive resin composition comprises a resin (A) soluble in alkaline aqueous solution, a crosslinking agent (B), a photopolymerization initiator (C) and a curing agent (D), wherein the curing agent (D) is a crystalline epoxy resin having a structure of Formula (1), wherein n represents an average value and is 1.0-2.0; R is H, a 1-4C alkyl group or a phenyl group; and k represents 1-4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition using a crystalline epoxy resin as a curing agent and a cured product thereof. More specifically, it is useful as a solder resist for printed wiring boards, interlayer insulating materials for multilayer printed wiring boards, solder resists for flexible printed wiring boards, plating resists, photosensitive optical waveguides, etc., developability, flexibility, flame resistance The present invention relates to a resin composition that provides a cured product excellent in electrical insulation, adhesion, solder heat resistance, chemical resistance, plating resistance, thermal stability, and the like, and the cured product.

A photosensitive resin composition using a photosensitive epoxycarboxylate compound has an excellent balance of various properties such as environmental, thermal, and mechanical properties and adhesion to a substrate. For this reason, it has been used for a long time in the fields of paints, coatings, adhesives and the like. Recently, it is well known that it is used in a wide range of industrial fields, such as electrical / electronic component manufacturing applications and printed wiring board manufacturing applications, and its application range is expanding. In printed wiring board applications, high precision and high density are required to reduce the size and weight of mobile devices and improve communication speed. As a result, the demands for solder resists are becoming increasingly sophisticated and more demanding than conventional requirements. However, while maintaining more flexibility, performance that can withstand flame resistance, substrate adhesion, high insulation, electroless gold plating, and thermal stability is required. It is not enough.
For example, Patent Document 1 discloses an epoxy (meth) acrylate resin having a biphenyl skeleton and a polybasic acid anhydride modified product thereof, and Patent Document 2 discloses a photosensitive resin composition having an epoxy resin having a biphenyl skeleton as a curing agent. Although these materials are described, flame retardance is improved by these resins alone, but it cannot be said that they are sufficient. Further, the epoxy resin having a biphenyl skeleton used in Patent Document 2 is in the form of a resin having no crystallinity, and the photosensitive resin composition using the epoxy resin has room for improvement in thermal stability.

JP-A-11-140144 JP 2004-155916 A JP 2006-2139 A Japanese Patent Application No. 2005-345259

  The object of the present invention is that the components do not easily dissolve, so the reaction does not proceed during the heating process such as solvent drying, and the resin composition that does not affect the development, excellent photosensitivity to active energy rays, Along with a resin composition that can be patterned by developing with a dilute aqueous alkali solution, which has a fine image that can correspond to the high functionality of the wiring board, it has sufficient flexibility even if it is thermally cured in a post-curing (post-cure) process, An object of the present invention is to provide a cured product of the resin composition suitable for a solder resist ink having high insulating properties, adhesion, flame retardancy, electroless gold plating resistance and thermal stability.

  In order to solve the above-mentioned problems, the present inventors have completed the present invention as a result of intensive studies on the photosensitive resin composition.

That is, the present invention
(1) In the photosensitive resin composition containing an aqueous alkali solution-soluble resin (A), a crosslinking agent (B), a photopolymerization initiator (C), and a curing agent (D), the curing agent (D) is represented by the formula (1).

(In the above formula (1), n represents an average value and is 1.0 to 2.0. R is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and k is 1) Represents 4)
A photosensitive resin composition characterized by being a crystalline epoxy resin having the structure:
(2) The photosensitive resin composition according to (1), wherein the curing agent (D) is an epoxy resin having a softening point or a melting point of 75 to 180 ° C.
(3) The photosensitive resin composition according to (1) or (2), wherein the curing agent (D) is an epoxy resin having a structure in which R is a hydrogen atom in the above formula (1),
(4) The total number of moles of the benzene ring in which the curing agent (D) has a structure in which R is a hydrogen atom in the above formula (1) and a methylene group is bonded to the p-position with respect to the glycidyl ether group. (P-coordination number) and the total number of moles of the benzene ring in which the methylene group is bonded to the o-position with respect to the glycidyl ether group (o-coordination number) is 0.57 ≦ p-coordination number / An epoxy resin satisfying (p-coordination number + o-coordination number) ≦ 0.90 and having a total content of 58 to 92% of the compound represented by n in the above formula (1) in GPC analysis. The photosensitive resin composition according to any one of (1) to (3),
(5) The photosensitive resin composition according to (1) or (2), wherein the curing agent (D) contains a compound represented by the formula (2),

(6) An aqueous alkali solution-soluble resin (A) reacts an epoxy compound (a) having two or more epoxy groups in the molecule with a monocarboxylic acid compound (b) having an ethylenically unsaturated group in the molecule. The photosensitive resin composition according to any one of (1) to (5), which is a reaction product of an epoxycarboxylate compound obtained in the above and a polybasic acid anhydride (c),
(7) The photosensitive resin composition according to (6), wherein the epoxy compound (a) having two or more epoxy groups in the molecule is represented by the formula (3):

(In the above formula (3), p is an integer of 1 to 3, m is an average value and is 1.0 to 5.0, and R ′ is a hydrogen atom or an alkyl having 1 to 4 carbon atoms. Each R ′ may be the same as or different from each other, s represents an integer of 1 to 4, and t represents an integer of 1 to 3.)
(8) A cured product of the photosensitive resin composition according to (1) to (7),
(9) A substrate having a layer of the cured product according to (8),
(10) The present invention relates to an article having the base material described in (9).

  The photosensitive resin composition of the present invention using the alkaline aqueous solution-soluble resin (A) and the curing agent represented by the formula (1) is thermally stable in the formation of a coating film by exposure and curing with ultraviolet rays. The cured product (cured product) of the present invention is excellent in sensitivity and sufficiently satisfies flame retardancy, flexibility, adhesion, pencil hardness, solvent resistance, acid resistance, heat resistance, gold plating resistance, etc. Especially, it is suitable for the photosensitive resin composition for printed wiring boards and the photosensitive resin composition for optical waveguide formation.

  The photosensitive resin composition of this invention is characterized by including said compound (A), a compound (B), a compound (C), and a compound (D).

  The alkaline aqueous solution-soluble resin (A) used in the present invention is not particularly limited as long as it is soluble in an alkaline aqueous solution, but the epoxy compound (a) having two or more epoxy groups in the molecule and the molecule The reaction product of an epoxycarboxylate compound obtained by reacting a monocarboxylic acid compound (b) having an ethylenically unsaturated group with a polybasic acid anhydride (c) is preferred. The epoxy compound (a) having two or more epoxy groups in the molecule used for producing the alkaline aqueous solution-soluble resin (A) preferably used in the present invention is particularly an epoxy compound having an epoxy equivalent of 100 to 900 g / equivalent. (A) is desirable. When the epoxy equivalent is less than 100 g / equivalent, the molecular weight of the resulting alkaline aqueous solution-soluble resin (A) may be small and film formation may be difficult or flexibility may not be obtained sufficiently. When exceeding, the introduction rate of the monocarboxylic acid compound (b) having an ethylenically unsaturated group is lowered, and the photosensitivity may be lowered.

  Specific examples of the epoxy compound (a) having two or more epoxy groups in the molecule include phenol novolac type epoxy resin, cresol novolac type epoxy resin, tris (hydroxyphenyl) methane type epoxy resin, dicyclopentadiene phenol type epoxy. Resin, phenol aralkyl type epoxy resin, bisphenol-A type epoxy resin, bisphenol-F type epoxy resin, biphenol type epoxy resin, bisphenol-A novolac type epoxy resin, naphthalene skeleton-containing epoxy resin, heterocyclic epoxy resin, etc. .

  Examples of the phenol novolac type epoxy resin include Epicron N-770 (manufactured by Dainippon Ink and Chemicals), DEN438 (manufactured by Dow Chemical Co., Ltd.), Epicoat 154 (manufactured by Japan Epoxy Resin Co., Ltd.), RE-306 ( Nippon Kayaku Co., Ltd.). Examples of the cresol novolac type epoxy resin include Epicron N-695 (manufactured by Dainippon Ink & Chemicals, Inc.), EOCN-102S, EOCN-103S, EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), UVR-6650 ( Union carbide).

  Examples of the trishydroxyphenylmethane type epoxy resin include EPPN-503, EPPN-502H, EPPN-501H (manufactured by Nippon Kayaku Co., Ltd.), TACTIX-742 (manufactured by Dow Chemical Co., Ltd.), Epicoat E1032H60 (Japan Epoxy Resin ( Etc.). Examples of the dicyclopentadiene phenol type epoxy resin include Epicron HP-7200 (manufactured by Dainippon Ink & Chemicals, Inc.), TACTIX-556 (manufactured by Dow Chemical Company), and the like.

  Examples of the phenol aralkyl type epoxy resin include epoxy resins having a biphenyl group in the skeleton such as NC-3000 and NC-3000-H (manufactured by Nippon Kayaku Co., Ltd.). Examples of the bisphenol type epoxy resin include Epicoat 828, Epicoat 1001 (manufactured by Japan Epoxy Resin Co., Ltd.), UVR-6410 (manufactured by Union Carbide), D.I. E. Bisphenol-A type epoxy resins such as R-331 (manufactured by Dow Chemical), YD-8125 (manufactured by Toto Kasei), UVR-6490 (manufactured by Union Carbide), YDF-8170 (manufactured by Toto Kasei) Bisphenol-F type epoxy resin and the like.

  Examples of the biphenol type epoxy resin include YX-4000 (manufactured by Japan Epoxy Resin Co., Ltd.), bixylenol type epoxy resin, YL-6121 (manufactured by Japan Epoxy Resin Co., Ltd.), and the like. Examples of the bisphenol A novolac type epoxy resin include Epicron N-880 (manufactured by Dainippon Ink & Chemicals, Inc.) and Epicoat E157S75 (manufactured by Japan Epoxy Resin Co., Ltd.).

  Examples of the naphthalene skeleton-containing epoxy resin include NC-7000L, NC-7300-L (manufactured by Nippon Kayaku Co., Ltd.), EXA-4750 (manufactured by Dainippon Ink & Chemicals, Inc.), and the like. Examples of the alicyclic epoxy resin include EHPE-3150 (manufactured by Daicel Chemical Industries, Ltd.). Examples of the heterocyclic epoxy resin include TEPIC, TEPIC-L, TEPIC-H, and TEPIC-S (all manufactured by Nissan Chemical Industries, Ltd.).

  As the epoxy compound (a) having two or more epoxy groups in the molecule, the phenol aralkyl type epoxy resin described above is expected in that flame retardancy can be improved because it contains many aromatic rings in the skeleton. (3)

(In the above formula (3), p is an integer of 1 to 3, m is an average value and is 1.0 to 5.0, and R ′ is a hydrogen atom or an alkyl having 1 to 4 carbon atoms. Each R ′ may be the same as or different from each other, s represents an integer of 1 to 4, and t represents an integer of 1 to 3.)
It is preferable to use an epoxy resin represented by formula (4).

(In the above formula (4), r represents an average value and is 1.0 to 5.0.)
An epoxy resin represented by the formula is particularly preferred. Specific examples include NC-3000 and NC-3000-H (manufactured by Nippon Kayaku Co., Ltd.).

  Examples of the monocarboxylic acid compound (b) having an ethylenically unsaturated group in the molecule used for producing the alkaline aqueous solution-soluble resin (A) preferably used in the present invention include acrylic acids, crotonic acid, and α-cyanocinnamic bark. Examples thereof include a reaction product of an acid, cinnamic acid, or a saturated or unsaturated dibasic acid and an unsaturated group-containing monoglycidyl compound. Examples of acrylic acids include (meth) acrylic acid, β-styrylacrylic acid, β-furfurylacrylic acid, saturated or unsaturated dibasic acid anhydride, and (meth) acrylate derivatives having one hydroxyl group in one molecule. And half-esters that are equimolar reactants, half-esters that are equimolar reactants of saturated or unsaturated dibasic acid and monoglycidyl (meth) acrylate derivatives, and the like, and photosensitive resin compositions (Meth) acrylic acid, a reaction product of (meth) acrylic acid and ε-caprolactone, or cinnamic acid is particularly preferable.

  As the polybasic acid anhydride (c) used for producing the alkaline aqueous solution-soluble resin (A), any polybasic acid anhydride (c) having at least one acid anhydride structure in the molecule can be used. Acid, acetic anhydride, phthalic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, ethylene glycol-bis (anhydrotrimellitate), glycerin-bis (anhydrotrimellitate) Monoacetate, 1,2,3,4, -butanetetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone Tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyl ether Lacarboxylic acid dianhydride, 2,2-bis (3,4-anhydrodicarboxyphenyl) propane, 2,2-bis (3,4-anhydrodicarboxyphenyl) hexafluoropropane, 5- (2,5 -Dioxotetrahydro-3-furanyl) -3-methylcyclohexene-1,2-dicarboxylic anhydride, 3a, 4,5,9b-tetrahydro-5- (tetrahydro-2,5-dioxo-3-furanyl)- Polybasic acid anhydrides selected from naphtho [1,2-c] furan-1,3-dione are particularly preferred.

  The production of the aqueous alkaline solution-soluble resin (A) involves the reaction between the epoxy compound (a) having two or more epoxy groups in the molecule and the monocarboxylic acid compound (b) having an ethylenically unsaturated group in the molecule. It can be obtained by reacting (hereinafter referred to as a second reaction) an epoxycarboxylate compound in which an alcoholic hydroxyl group has been formed (hereinafter referred to as a first reaction) and a polybasic acid anhydride (c).

  The first reaction is a solvent-free or solvent having no alcoholic hydroxyl group, specifically, for example, ketones such as acetone, ethylmethylketone, cyclohexanone, aromatic carbonization such as benzene, toluene, xylene, tetramethylbenzene, etc. Hydrogens, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether and other glycol ethers, ethyl acetate, butyl acetate, methyl cellosolve acetate, ethyl Cellosolve acetate, butyl cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate, glutaric acid dial , Esters such as dialkyl succinate and dialkyl adipate, cyclic esters such as γ-butyrolactone, petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha, and the above-mentioned crosslinking agent (B ) Etc. alone or in a mixed organic solvent.

  The raw material charge ratio in this reaction is preferably 80 to 120 equivalent% of the monocarboxylic acid compound (b) having an ethylenically unsaturated group in the molecule with respect to 1 equivalent of the epoxy compound (a). When deviating from this range, gelation may occur during the second reaction, and the thermal stability of the finally obtained alkaline aqueous solution-soluble resin (A) may be lowered.

During the reaction, it is preferable to use a catalyst to promote the reaction, and the amount of the catalyst used is 0.1 to 10% by weight based on the reaction product. The reaction temperature at that time is 60 to 150 ° C., and the reaction time is preferably 5 to 60 hours. Specific examples of the catalyst used include, for example, triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, triphenylphosphine, triphenylstibine, methyltriphenylstibine, chromium octoate, octane Examples include zirconium acid.
Moreover, it is preferable to use a thermal polymerization inhibitor at the time of reaction, and the usage-amount of this thermal polymerization inhibitor is 0.05 to 10 weight% with respect to the reaction material. Specific examples of the thermal polymerization inhibitor used include hydroquinone monomethyl ether, 2-methylhydroquinone, hydroquinone, diphenylpicrylhydrazine, diphenylamine, 3,5-ditertiarybutyl-4hydroxytoluene, 2,6-di-tert- Examples include butyl-p-cresol.
The first reaction has an end point when the sample oxidation is 1 mg · KOH / g or less, preferably 0.5 mg · KOH / g or less, with appropriate sampling.

  The second reaction is an esterification reaction in which the polybasic acid anhydride (c) is reacted with the reaction solution after the first reaction is completed. Although the reaction can be carried out without a catalyst, a basic catalyst can be used to promote the reaction, and the amount of the catalyst used is 10% by weight or less based on the reaction product. The reaction temperature at this time is 40 to 120 ° C., and the reaction time is preferably 5 to 60 hours.

  In the charged amount of each component, as the polybasic acid anhydride (c), it is preferable to add a calculated value such that the solid content acid value of the alkaline aqueous solution-soluble resin (A) is 50 to 150 mg · KOH / g. . When the acid value of the solid content is less than 50 mg · KOH / g, the solubility in an alkaline aqueous solution is insufficient, and when patterning is performed, there is a fear that it remains as a residue or in the worst case, patterning cannot be performed. On the other hand, when the solid content acid value exceeds 150 mg · KOH / g, the solubility in an alkaline aqueous solution becomes too high, and the photocured pattern may be peeled off.

  The aqueous alkaline solution-soluble resin (A) thus obtained can be isolated by removing it with an appropriate method when the solvent is used. The alkaline aqueous solution-soluble resin (A) is usually soluble in an alkaline aqueous solution, but is also soluble in the solvent, and when used for a solder resist, a plating resist, etc., it can be developed with a solvent.

  Specific examples of the alkaline aqueous solution-soluble resin (A) include KAYARAD PCR-1169H, KAYARAD CCR-1159H, KAYARAD TCR-1310H, KAYARAD ZAR-1395H, KAYARAD ZFR-1401H, and KAYARAD ZCR-1361 (all Nippon Kayaku Co., Ltd.) ).

  As a content rate of the above-mentioned aqueous alkali-soluble resin (A) used for the photosensitive resin composition of the present invention, when the solid content of the photosensitive resin composition is 100% by weight, usually 15 to 70% by weight, preferably Is 20 to 60% by weight.

  Specific examples of the crosslinking agent (B) used in the photosensitive resin composition of the present invention include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol mono ( (Meth) acrylate, carbitol (meth) acrylate, acryloylmorpholine, hydroxyl group-containing (meth) acrylate (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol mono (meta ) Acrylate etc.) and polycarboxylic acid anhydrides (eg succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, etc.) (Meth) acrylate, tripropy Glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, glycerin polypropoxytri (meth) acrylate, and ε-caprolactone adduct of hydroxypenic acid neopenglycol Di (meth) acrylate (for example, KAYARAD HX-220, HX-620, etc., manufactured by Nippon Kayaku Co., Ltd.), pentaerythritol tetra (meth) acrylate, poly (meta) of the reaction product of dipentaerythritol and ε-caprolactone ) Acrylate, dipentaerythritol poly (meth) acrylate, mono- or polyglycidyl compounds (eg, butyl glycidyl ether, phenyl glycidyl ether, polyethylene glycol diglycidyl ether) Polypropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, glycerin polyglycidyl ether, glycerin polyethoxyglycidyl ether, trimethylolpropane polyglycidyl ether, trimethylolpropane polyethoxypolyglycidyl ether And epoxy (meth) acrylate which is a reaction product of (meth) acrylic acid, etc. As the crosslinking agent (B), two or more of the above may be used in combination. When the solid content of the conductive resin composition is 100% by weight, it is usually 2 to 40% by weight, preferably 5 to 30% by weight.

  Specific examples of the photopolymerization initiator (C) used in the photosensitive resin composition of the present invention include, for example, benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether; acetophenone, 2 , 2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropan-1-one, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [ Acetophenones such as 4- (methylthio) phenyl] -2-morpholinopropan-1-one; ant such as 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-chloroanthraquinone, 2-amylanthraquinone Quinones; thioxanthones such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide Benzophenones such as 4,4′-bismethylaminobenzophenone; phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide It is done. The addition ratio of these is usually 1 to 30% by weight, preferably 2 to 25% by weight, when the solid content of the photosensitive resin composition is 100% by weight.

  These photopolymerization initiators (C) can be used alone or as a mixture of two or more thereof, and further, tertiary amines such as triethanolamine and methyldiethanolamine, N, N-dimethylaminobenzoic acid ethyl ester, N, N -It can be used in combination with accelerators such as benzoic acid derivatives such as dimethylaminobenzoic acid isoamyl ester. The addition amount of these accelerators is preferably 100% or less with respect to the photopolymerization initiator (C).

  The curing agent (D) used in the photosensitive resin composition of the present invention has the formula (1)

(In the above formula (1), n represents an average value and is 1.0 to 2.0. R is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and k is 1) The thermal stability of the photosensitive resin composition is a crystalline epoxy resin represented by -4, and is an epoxy resin having a softening point or a melting point of 75 to 180 ° C, preferably 85 to 170 ° C. It contributes to the improvement. The crystalline epoxy resin represented by the above formula (1), which is an essential component of the present invention, is specifically obtained by the following two methods, but is not limited to these examples.

  As a first example, there is a crystalline epoxy resin in which R is a hydrogen atom in the formula (1). The crystalline epoxy resin is phenol and the following formula (5)

(In the above formula (5), X represents a chlorine atom, a bromine atom, a methoxy group, an ethoxy group, or a hydroxyl group.) A biphenyl compound represented by a condensation reaction in the presence of a strongly acidic substance, and then unreacted It is obtained by glycidyl etherification of a phenol resin obtained by heating and removing phenol and impurities. By using a strongly acidic substance, the phenol resin has a total number of moles of benzene rings (p-coordination number) in which a methylene group is bonded to the p-position with respect to the phenol group and an o-position with respect to the phenol group. Is represented by the relationship (p-coordination number / (p-coordination number + o-coordination number)) of the total number of moles (o-coordination number) of the benzene ring to which the methylene group is bonded. (Referred to as “orientation ratio”) becomes the p-position dominant, and the p-orientation ratio of the crystalline epoxy resin in which R is a hydrogen atom in the formula (1) is 0.57 ≦ p-orientation ratio ≦ 0.90.

  In the above condensation reaction, the feed ratio of the raw material is usually 3 to 40 mol of phenol with respect to 1 mol of the compound of the formula (5).

  Examples of the compound of the formula (5) include 4,4′-bis (chloromethyl) -1,1′-biphenyl, 4,4′-bis (bromomethyl) -1,1′-biphenyl, 4,4′- Bis (methoxymethyl) -1,1′-biphenyl, 4,4′-bis (ethoxymethyl) -1,1′-biphenyl and the like can be mentioned.

  Various substances can be used as the strongly acidic substance, and examples thereof include organic or inorganic acids such as hydrogen bromide, sulfuric acid, methanesulfonic acid, and trifluoromethanesulfonic acid. Of these, hydrobromic acid is preferable. The amount of these strongly acidic substances to be used varies depending on the type of the catalyst, but it may be added within a range of 0.005 to 5 times the molar ratio of the compound of formula (5).

  The condensation reaction can be performed in the absence of a solvent or in the presence of a solvent. When a solvent is used, examples of the solvent that can be used include methanol, ethanol, isopropanol, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene. As a usage-amount of a solvent, it is 5-300 weight% normally with respect to the total weight of a compound represented with a phenol and Formula (5). The condensation reaction temperature is usually 0 to 120 ° C., and the reaction time is usually 1 to 10 hours.

  After completion of the condensation reaction, the acid catalyst is removed by neutralization, washing with water, etc., and then the solvent used and unreacted phenol are removed as necessary under heating and reduced pressure. Although purification such as recrystallization can be performed if necessary, it is disadvantageous in terms of cost. Solvents that can be used for recrystallization include toluene, methyl ethyl ketone, acetone, methyl isobutyl ketone, n-hexane, methanol, ethanol, and the like, but are not limited thereto, and various solvents may be mixed. In recrystallization, these solvents are heated to dissolve the reaction mixture, and then cooled and filtered.

  A crystalline epoxy resin represented by the above formula (1) can be obtained by glycidyl etherification of the phenol resin thus obtained in the presence of an alkali metal hydroxide in epihalohydrin. In the reaction for obtaining the epoxy resin, an aqueous solution of the alkali metal hydroxide may be used. In that case, the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system and the reaction is performed under reduced pressure or under normal conditions. A method may be used in which water and epihalohydrin are continuously distilled under pressure, liquid separation is performed, water is removed, and epihalohydrin is continuously returned to the reaction system.

  A phenol obtained by adding a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride as a catalyst to a mixture of phenol resin and epihalohydrin and reacting at 50 to 150 ° C. for 0.5 to 8 hours. A crystalline epoxy resin can also be obtained by adding a solid or aqueous solution of an alkali metal hydroxide to a halohydrin etherification product of a resin and reacting at 20 to 120 ° C. for 1 to 10 hours to dehydrohalogenate (ring closure). .

  Usually, the amount of epihalohydrin used in these reactions is usually 0.8 to 12 mol, preferably 0.9 to 11 mol, per mol of the hydroxyl group of the phenol resin. In this case, it is preferable to carry out the reaction by adding an alcohol such as methanol or ethanol, an aprotic polar solvent such as dimethyl sulfone or dimethyl sulfoxide, etc. in order to make the reaction proceed smoothly.

  When using alcohol, the amount of its use is 2-20 weight% normally with respect to the quantity of epihalohydrin, Preferably it is 4-15 weight%. Moreover, when using an aprotic polar solvent, it is 5-150 weight% normally with respect to the quantity of epihalohydrin, Preferably it is 10-140 weight%.

After the reaction product of these epoxidation reactions is washed with water or without washing with water, the epihalohydrin, the solvent and the like are removed under heating and reduced pressure. In order to make the epoxy resin less hydrolyzable halogen, the recovered epoxy resin is dissolved in a solvent such as toluene or methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added. The reaction can be carried out to ensure the ring closure. In this case, the amount of alkali metal hydroxide used is usually 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, relative to 1 mol of the hydroxyl group in the phenol resin used for epoxidation. The reaction temperature is usually 50 to 120 ° C., and the reaction time is usually 0.5 to 2 hours.
After completion of the reaction, the produced salt is removed by filtration, washing with water, etc., and the solvent is distilled off under heating and reduced pressure to obtain the crystalline epoxy resin represented by the formula (1).

  As described above, the crystalline epoxy resin thus obtained has a p-orientation ratio satisfying 0.57 ≦ p-orientation ratio ≦ 0.90, and in GPC analysis, n in the above formula (1) is represented by 1. The total content of the compounds is 58 to 92%. A high p-orientation ratio and a large number of bifunctional components are effective in improving the crystallinity of the glycidyl etherified epoxy resin. Those outside this range are difficult to handle because the crystals do not form when cooled to room temperature after distilling off the solvent under reduced pressure, or the epoxy resin is too crystalline. This is not preferable because crystals are precipitated during the production of the epoxy resin and the yield is reduced.

  As a 2nd example, what is R is a C1-C4 alkyl group among the crystalline epoxy resins represented by said Formula (1) is mentioned. For example, when R is a methyl group, the crystalline epoxy resin undergoes a condensation reaction between p-cresol and the biphenyl compound represented by the above formula (5), and then removes unreacted p-cresol and impurities by heating. It can be obtained by glycidyl etherification of the phenol resin obtained. The crystalline epoxy resin has a high crystallinity although a methylene group is bonded to the o-position with respect to the glycidyl ether group.

  In the above condensation reaction, the charging ratio of the raw material is usually 10 to 30 mol, preferably 15 to 25 mol, of p-cresol with respect to 1 mol of the compound of the formula (5).

  In the condensation, an acid catalyst can be added as necessary during the reaction. Specific examples include various organic or inorganic acids such as sulfuric acid, p-toluenesulfonic acid, and oxalic acid, Friedel-Crafts type catalysts such as stannic chloride, zinc chloride, and ferric chloride. Can be mentioned. Of these, stannic chloride, sulfuric acid, and p-toluenesulfonic acid are preferable. The amount of the acid catalyst used varies depending on the type of the catalyst, but it may be added in the range of 0.0005 to 5% by weight with respect to the compound of the formula (5).

  The condensation reaction can be performed in the absence of a solvent or in the presence of a solvent. When a solvent is used, examples of the solvent that can be used include methanol, ethanol, isopropanol, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene. The amount of the solvent used is usually 10 to 300% by weight, preferably 20 to 250% by weight, based on the total weight of p-cresol and the compound represented by formula (5). The condensation reaction temperature is usually 40 to 150 ° C., and the reaction time is usually 1 to 10 hours.

  After completion of the condensation reaction, the acid catalyst is removed by neutralization, washing with water, etc., and then the solvent used and unreacted p-cresol are removed as necessary under heating and reduced pressure. Although purification such as recrystallization can be performed if necessary, it is disadvantageous in terms of cost. Solvents that can be used for recrystallization include toluene, methyl ethyl ketone, acetone, methyl isobutyl ketone, n-hexane, methanol, ethanol, and the like, but are not limited thereto, and various solvents may be mixed. In recrystallization, these solvents are heated to dissolve the reaction mixture, and then cooled and filtered.

  An epoxy resin mainly composed of a compound represented by the following formula (2) can be obtained by glycidyl etherifying the phenol resin thus obtained in an epihalohydrin in the presence of an alkali metal hydroxide. In the reaction for obtaining the epoxy resin, an aqueous solution of the alkali metal hydroxide may be used. In that case, the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system and the pressure is reduced or normal pressure. A method may be used in which water and epihalohydrin are continuously distilled out, liquid is separated, water is removed, and epihalohydrin is continuously returned to the reaction system.

  A phenol obtained by adding a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride as a catalyst to a mixture of phenol resin and epihalohydrin and reacting at 50 to 150 ° C. for 0.5 to 8 hours. A method of adding a solid or aqueous solution of an alkali metal hydroxide to a halohydrin etherified resin and reacting at 20 to 120 ° C. for 1 to 10 hours to dehydrohalogenate (ring closure) may be used.

  Usually, the amount of epihalohydrin used in these reactions is usually 0.8 to 12 mol, preferably 0.9 to 11 mol, per mol of the hydroxyl group of the phenol resin. In this case, it is preferable to carry out the reaction by adding an alcohol such as methanol or ethanol, an aprotic polar solvent such as dimethyl sulfone or dimethyl sulfoxide, etc. in order to make the reaction proceed smoothly.

  When using alcohol, the amount of its use is 2-20 weight% normally with respect to the quantity of epihalohydrin, Preferably it is 4-15 weight%. Moreover, when using an aprotic polar solvent, it is 5-150 weight% normally with respect to the quantity of epihalohydrin, Preferably it is 10-140 weight%.

After the reaction product of these epoxidation reactions is washed with water or without washing with water, the epihalohydrin, the solvent and the like are removed under heating and reduced pressure. In order to make the epoxy resin less hydrolyzable halogen, the recovered epoxy resin is dissolved in a solvent such as toluene or methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added. The reaction can be carried out to ensure the ring closure. In this case, the amount of alkali metal hydroxide used is usually 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, relative to 1 equivalent of the hydroxyl group of the phenol resin used for epoxidation. The reaction temperature is usually 50 to 120 ° C., and the reaction time is usually 0.5 to 2 hours.
After completion of the reaction, the produced salt is removed by filtration, washing with water, etc., and the solvent is distilled off under heating and reduced pressure to obtain a crystalline epoxy resin represented by the above formula (2).

  The epoxy resin used in the present invention may be subjected to a treatment for promoting crystallization or a recrystallization treatment as necessary. Examples of the treatment for promoting crystallization include a method of applying shear to the resin and a method of using a seed crystal. In the recrystallization process, toluene, methyl ethyl ketone, acetone, methyl isobutyl ketone, n-hexane, methanol, ethanol and the like can be used as a solvent that can be used for recrystallization. It doesn't matter. Recrystallization has no problem in the usual method of heating these solvents and dissolving the reaction mixture, followed by cooling and filtration.

  The curing agent (D) is particularly preferably used when a cured coating film that reacts with a carboxyl group remaining in the resin coating after photo-curing by heating to obtain a stronger chemical resistance.

  As the curing agent (D), a compound of the formula (1) is preferably used, a methylene group is bonded to the p-position with respect to the glycidyl ether group which is crystalline among the compounds of the formula (1), and More preferably, R is a hydrogen atom or a compound represented by formula (2). Moreover, the hardening | curing agent (D) may contain the compound represented by Formula (2), and in this case, the compound represented by Formula (2) is 60 among the total weight of a hardening | curing agent (D). It is preferably ˜100%.

  Moreover, in this invention, another epoxy resin can also be used together as a hardening | curing agent (D). Specific examples include phenol novolac type epoxy resins, cresol novolac type epoxy resins, tris (hydroxyphenyl) methane type epoxy resins, tetrakis (phenol) ethane type epoxy resins, dicyclopentadiene phenol type epoxy resins, phenol aralkyl type epoxy resins, Examples thereof include bisphenol-A type epoxy resins, bisphenol-F type epoxy resins, biphenol type epoxy resins, bisphenol-A novolac type epoxy resins, naphthalene skeleton-containing epoxy resins, and triglycidyl isocyanurate type epoxy resins. When used in combination, the proportion of the epoxy resin represented by formula (1) in the total epoxy resin is preferably 20% by weight or more, and more preferably 30% by weight or more. As the addition ratio of the curing agent (D), the epoxy equivalent of the curing agent (D) is 200% or less and 80% or less based on the carboxyl group equivalent calculated from the solid content acid value and the amount used of the alkaline aqueous solution-soluble resin (A). The above amounts are preferred. If this amount exceeds 200%, the developability of the photosensitive resin composition of the present invention may be remarkably lowered, which is not preferable. On the other hand, if it is less than 80%, the moisture resistance reliability and electrical properties of the cured product may be deteriorated, which is not preferable.

  Furthermore, various additives as required, for example, fillers such as talc, barium sulfate, calcium carbonate, magnesium carbonate, barium titanate, aluminum hydroxide, aluminum oxide, silica, clay, thixotropic agent such as aerosil; phthalocyanine blue , Colorants such as phthalocyanine green and titanium oxide, silicone, fluorine leveling agents and antifoaming agents; polymerization inhibitors such as hydroquinone and hydroquinone monomethyl ether, imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole , Tertiary amines such as 2- (dimethylaminomethyl) phenol, 1,8-diaza-bicyclo (5,4,0) undecene-7, phosphines such as triphenylphosphine, and thermosetting catalysts such as melamine Etc. of the composition It can be added for the purpose of increasing the performance. In addition, the addition amount of a thermosetting catalyst is 0.3 to 5.0%. A solvent can also be added. The solvent used in this case is not particularly limited, but it is preferable to use a solvent that can be used for the synthesis of the alkaline aqueous solution-soluble resin (A).

  In addition, although the above-mentioned hardening | curing agent (D) may be previously mixed with the said resin composition, it can also be mixed and used before application | coating to a printed wiring board. That is, it is blended into a two-pack type of a main agent solution mainly composed of the component (A) and an epoxy curing accelerator and the like and a curing agent solution mainly composed of the curing agent (D), and these are mixed in use. And preferably used.

  The photosensitive resin composition of the present invention can also be used as a dry film resist having a structure in which the resin composition is sandwiched between a support film and a protective film.

  The photosensitive resin composition (liquid or film-like) of the present invention is useful as a resist material such as an insulating material between electronic components, an optical waveguide connecting optical components, a solder resist for printed circuit boards, and a coverlay. In addition, it can also be used as a color filter, printing ink, sealant, paint, coating agent, adhesive and the like.

  The cured product of the present invention is obtained by curing the above resin composition of the present invention by irradiation with energy rays such as ultraviolet rays. Curing can be performed by conventional methods by irradiation with energy rays such as ultraviolet rays. For example, in the case of irradiating ultraviolet rays, an ultraviolet generator such as a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, or an ultraviolet light emitting laser (such as an excimer laser) may be used.

  The cured product of the present invention is used, for example, as a resist film, an interlayer insulating material for a build-up method, or an optical waveguide for an electric / electronic / optical base material such as a printed board, an optoelectronic board or an optical board. Specific examples of these include articles such as computers, home appliances, and portable devices. The thickness of the cured product layer is about 0.5 to 160 μm, and preferably about 1 to 100 μm.

The printed circuit board of the present invention can be obtained, for example, as follows. That is, when a liquid resin composition is used, the present invention is applied to a printed wiring board with a film thickness of 5 to 160 μm by a screen printing method, a spray method, a roll coating method, an electrostatic coating method, a curtain coating method, or the like. A coating film can be formed by applying the composition and drying the coating film at a temperature of usually 50 to 110 ° C, preferably 60 to 100 ° C. Thereafter, the coating film is directly or indirectly irradiated with high energy rays such as ultraviolet rays with an intensity of about 10 to 2000 mJ / cm ² through a photomask having an exposure pattern such as a negative film, and the unexposed portion is described later. Using the liquid, development is performed, for example, by spraying, rocking dipping, brushing, scrubbing, or the like. Thereafter, if necessary, further ultraviolet irradiation is performed, and then heat treatment is usually performed at a temperature of 100 to 200 ° C., preferably 140 to 180 ° C., so that the gold plating property is excellent, and heat resistance, solvent resistance, acid resistance, A printed wiring board having a permanent protective film that satisfies various properties such as adhesion and flexibility can be obtained.

  Examples of the alkaline aqueous solution used in the above development include potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium phosphate, potassium phosphate and other inorganic alkaline aqueous solutions and tetramethylammonium hydrous. Organic alkaline aqueous solutions such as oxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, monoethanolamine, diethanolamine, and triethanolamine can be used.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples. In the following, parts are parts by weight unless otherwise specified. The softening point, bifunctional component content, epoxy equivalent, melt viscosity, and p-orientation ratio were measured under the following conditions.

-Softening point It measured by the method of JISK-7234.
-Bifunctional component content The bifunctional component content was calculated | required by GPC measurement.
Specifications Column: GPC KF-803 + GPC KF-802.5 + GPC KF-802 + GPC KF-801
(Manufactured by Showa Denko)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran Flow rate: 1 ml / min.
Detection: RI
-Epoxy equivalent It measured by the method of JISK-7236.
Melt viscosity Melt viscosity in cone plate method at 150 ° C. Measuring instrument: Cone plate (ICI) high temperature viscometer (manufactured by RESECH EQUIIPMENT (LONDON) LTD.)
Measurement range of cone: 0 to 0.50 Pa · s
Sample amount: 0.05 ± 0.005g
・ P-orientation ratio
^The p-orientation ratio was determined by ¹³ C-NMR measurement.
Measuring device: Gemini 300 (manufactured by Varian)

Synthesis example 1
In a 1 L flask equipped with a stirrer and a reflux tube, as an epoxy compound (a), Nippon Kayaku NC-3000H (biphenyl type epoxy resin, epoxy equivalent: 288 g / equivalent, softening point 69 ° C., repetition number 2.6) ) 288.0 g, 74.2 g of acrylic acid (molecular weight: 72.06) as an unsaturated monocarboxylic acid compound (b) in the molecule, 155.2 g of carbitol acetate as a reaction solvent, and a thermal polymerization inhibitor Charge 1.552 g of 2,6-di-tert-butyl-p-cresol and 1.552 g of triphenylphosphine as a reaction catalyst, and the acid value of the reaction solution at a temperature of 98 ° C. is 0.5 mg · KOH / g or less To give an epoxy acrylate resin.
Next, 112.4 g of carbitol acetate as a solvent for reaction and 134.8 g of tetrahydrophthalic anhydride as a polybasic acid anhydride (c) were added to this reaction solution, and reacted at 95 ° C. for 5 hours to obtain an aqueous alkali solution-soluble resin (A). A resin solution containing 65% by weight was obtained (this solution is referred to as A-1). When the acid value was measured, it was 67.0 mg · KOH / g (solid content acid value: 103.1 mg · KOH / g).

Synthesis example 2
A four-necked flask equipped with a stirrer, a thermometer and a condenser was charged with 955 parts of phenol and 172 parts of 47% hydrobromic acid, and stirred at 30 ° C., 4,4′-bis (chloromethyl) -1,1 ′. -125 parts of biphenyl was added and reacted at 30 ° C for 6 hours and at 80 ° C for 2 hours. After completion of the reaction, neutralization was performed using a 25% aqueous sodium hydroxide solution, 2000 parts of methyl isobutyl ketone was added, and washing with water was repeated. Next, 173 parts of phenol resin (P-1) was obtained by distilling off unreacted phenol and methyl isobutyl ketone from the oil layer under heating and reduced pressure. The softening point of the obtained phenol resin (P-1) was 174 ° C.

Synthesis example 3
Subsequently, 376 parts of phenol resin (P-1), 1110 parts of epichlorohydrin, and 222 parts of dimethyl sulfoxide were charged into a four-necked flask equipped with a stirrer, a thermometer, and a condenser, dissolved, and then heated to 50 ° C. to form flaky sodium hydroxide. (Purity 99%) 82 parts were added over 90 minutes, and then further reacted at 50 ° C. for 2 hours and at 75 ° C. for 1 hour. Subsequently, water washing was repeated until the water washing liquid of the reaction mixture became neutral, and then excess epichlorohydrin was distilled off from the oil layer under heating under reduced pressure, and 976 parts of methyl isobutyl ketone was added to the residue and dissolved. Further, this methyl isobutyl ketone solution was heated to 75 ° C., 20 parts of 30% by weight sodium hydroxide aqueous solution was added and reacted for 1 hour, and then the water washing was repeated until the water washing solution of the reaction mixture became neutral. Next, 464 parts of epoxy resin (D-1) was obtained by distilling off methyl isobutyl ketone at 180 ° C. under heating and reduced pressure from the oil layer. The obtained epoxy resin (D-1: R is a hydrogen atom in formula (1)) showed crystallinity, epoxy equivalent was 251 g / eq, softening point was 98 ° C., and melt viscosity was 0.05 Pa · s. . As a result of GPC analysis on the obtained epoxy resin, the content of bifunctional components was 79%, and as a result of ¹³ C-NMR analysis, the p-orientation ratio was 0.64.

Synthesis example 4
A 4-necked flask equipped with a stirrer, a thermometer, and a condenser was charged with 7570 parts of p-cresol and 7 parts of p-toluenesulfonic acid, and stirred at 70 ° C., 4,4′-bis (chloromethyl) -1,1. 879 parts of '-biphenyl was added over 2 hours and reacted at 70 ° C for 2 hours. After completion of the reaction, 10,000 parts of methyl isobutyl ketone was added and washing with water was repeated. Subsequently, 1273 parts of phenol resin (P-2) was obtained by distilling off unreacted p-cresol and methyl isobutyl ketone under heating and reduced pressure from the oil layer. The softening point of the obtained phenol resin (P-2) was 59 ° C.

Synthesis example 5
In a four-necked flask equipped with a stirrer, a thermometer and a condenser, 813 parts of the phenol resin (P-2) obtained in Synthesis Example 4, 2221 parts of epichlorohydrin and 555 parts of dimethyl sulfoxide were charged and dissolved, and then heated to 50 ° C. 165 parts of flaky sodium hydroxide (99% purity) were added over 90 minutes, and then reacted at 50 ° C. for 2 hours and at 75 ° C. for 1 hour. Subsequently, water washing was repeated until the water washing liquid of the reaction mixture became neutral, and then excess epichlorohydrin was distilled off from the oil layer under heating and reduced pressure, and 2070 parts of methyl isobutyl ketone was added to the residue and dissolved. Further, this methyl isobutyl ketone solution was heated to 75 ° C., 40 parts of a 30% by weight aqueous sodium hydroxide solution was added and reacted for 1 hour, followed by repeated water washing until the water washing solution of the reaction mixture became neutral. Subsequently, methyl isobutyl ketone was distilled off from the oil layer under reduced pressure by heating at 180 ° C., then stirred at 130 ° C., and taken out when the resin started to become turbid due to crystallization, and then the epoxy resin (D-2: represented by the formula (2) was used. 990 parts of compound obtained). The resulting epoxy resin (D-2) was a crystalline solid, having an epoxy equivalent of 274 g / eq, a softening point of 139 ° C., and a melt viscosity of 0.03 Pa · s. As a result of GPC analysis, the peak area of the compound represented by formula (2) was 73%.

Examples 1 and 2 and Comparative Example 1
(A-1), (D-1), (D-2) obtained in Synthesis Examples 1 to 5, and a comparative curing agent (D) of formula (4) having no crystallinity. Using NC-3000 having a structure (softening point: 57 ° C., epoxy equivalent: 276 g / equivalent, repetition number 1.9, manufactured by Nippon Kayaku Co., Ltd.), mixing at the blending ratio shown in Table 1, if necessary The photosensitive resin composition of the present invention was obtained by kneading with a three-roll mill. This was applied to a printed circuit board by a screen printing method so that the dry film thickness was 15 to 25 μm, and the coating film was dried with a hot air dryer at 80 ° C. for 30 minutes. Next, ultraviolet rays were irradiated through a mask on which a circuit pattern was drawn using an ultraviolet exposure device (Oak Manufacturing Co., Ltd., model HMW-680GW). Thereafter, spray development was performed with a 1% aqueous sodium carbonate solution to remove the resin in the non-ultraviolet irradiated area. After washing with water and drying, the printed circuit board was subjected to a heat curing reaction in a hot air drier at 150 ° C. for 60 minutes to obtain a cured film. For the dried film, thermal stability, tackiness, developability, resolution, and photosensitivity, and for the obtained cured film, surface gloss, flame retardancy, substrate warpage, flexibility, adhesion, Pencil hardness, solvent resistance, acid resistance, heat resistance, gold plating resistance, and various reliability tests were performed. The results are shown in Table 2. The test method and evaluation method are as follows.

(Thermal stability) After coating on the substrate, it was dried at 80 ° C for 30 minutes, 50 minutes, and 70 minutes, respectively, and completely developed in 1% sodium carbonate aqueous solution and developed at a spray pressure of 2.0 kg / cm ^2. The drying time that can be removed was evaluated.

(Tackiness) Absorbent cotton was rubbed on the dried film applied to the substrate, and the tackiness of the film was evaluated.
○: Absorbent cotton does not stick.
× ··· Absorbent cotton lint sticks to the membrane.

(Developability) The following evaluation criteria were used.
○: The ink was completely removed during development and development was possible.
× ····· There are parts that are not developed during development.

(Resolution) in the coating film after drying, are brought into close contact with 50μm of negative pattern exposure by irradiation with ultraviolet light at an accumulated light intensity 200 mJ / cm ^2. Next, development is performed with a 1% sodium carbonate aqueous solution for 60 seconds at a spray pressure of 2.0 kg / cm ² , and the transfer pattern is observed with a microscope. The following criteria were used:
○ The pattern edge is a straight line and is resolved.
X: Peeling or pattern edges are jagged.

(Photosensitivity) A step tablet 21 (manufactured by Kodak Co., Ltd.) is brought into intimate contact with the dried coating film and irradiated with ultraviolet rays having an integrated light amount of 500 mJ / cm ² . Next, development is performed with a 1% sodium carbonate aqueous solution for 60 seconds at a spray pressure of 2.0 kg / cm ² , and the number of steps of the coating film remaining without development is confirmed.

(Surface gloss) The dried coating film is exposed to 500 mJ / cm ² of ultraviolet rays. Next, development is performed with a 1% aqueous sodium carbonate solution for 60 seconds at a spray pressure of 2.0 kg / cm ² , and the dried cured film is observed. The following criteria were used:
○ ・ ・ ・ ・ No cloudiness is seen at all × ・ ・ ・ ・ Slight cloudiness is seen

(Flame Retardancy) After curing, a resin-only film excluding the base material is created to produce a 1 cm wide strip. Next, observe the phenomenon until the flame disappears.
○ ・ ・ ・ Fire extinguisher × ・ ・ ・ Burn

(Substrate sled) The following criteria were used.
○ ········································································· •

(Flexibility) The cured film is bent at 180 ° C. and observed. The following criteria were used:
○ ···· No crack on the film surface × ··· The film surface breaks

(Adhesiveness) According to JIS K5400, 100 test pieces having 1 mm diameters were made on a test piece, and a peeling test was performed using a cellophane tape. The peeled state of the goblet was observed and evaluated according to the following criteria.
○ ··············································

  (Pencil hardness) Evaluation was performed according to JIS K5400.

(Solvent resistance) The test piece is immersed in isopropyl alcohol at room temperature for 30 minutes. After confirming that there was no abnormality in the appearance, a peeling test using a cellophane tape was performed, and evaluation was performed according to the following criteria.
○ ··· There is no abnormality in the appearance of the coating film, and there is no swelling or peeling × ·······

(Acid resistance) The test piece is immersed in a 10% hydrochloric acid aqueous solution at room temperature for 30 minutes. After confirming that there was no abnormality in the appearance, a peeling test using a cellophane tape was performed, and evaluation was performed according to the following criteria.
○ ··· There is no abnormality in the appearance of the coating film, and there is no swelling or peeling × ·········

(Heat resistance) A rosin-based plax was applied to a test piece and immersed in a solder bath at 260 ° C. for 5 seconds. This was defined as 1 cycle and repeated 3 cycles. After cooling to room temperature, a peeling test using a cellophane tape was performed, and evaluation was performed according to the following criteria.
○ ··· There is no abnormality in the appearance of the coating film and there is no swelling or peeling × ········

(Gold Plating Resistance) The test substrate was immersed in an acid degreasing solution (manufactured by Nihon McDermitt, 20 vol% aqueous solution of Metex L-5B) for 3 minutes, washed with water, and then a 14.4 wt% ammonium persulfate aqueous solution. The test substrate was immersed for 3 minutes at room temperature, washed with water, and further immersed in a 10 vol% sulfuric acid aqueous solution for 1 minute at room temperature and then washed with water. Next, this substrate was immersed in a 30 ° C. catalyst solution (Meltex, 10 vol% aqueous solution of metal plate activator 350) for 7 minutes, washed with water, and 85 ° C. nickel plating solution (Meltex, Melplate Ni— After immersing in 865M 20vol% aqueous solution, pH 4.6) for 20 minutes and performing nickel plating, it was immersed in 10vol% sulfuric acid aqueous solution for 1 minute at room temperature and washed with water. Next, the test substrate was immersed for 10 minutes in a gold plating solution at 95 ° C. (Meltex, aqueous solution of Aurolectroles UP 15 vol% and potassium gold cyanide 3 vol%, pH 6), electroless gold plating was performed, and then washed with water. It was immersed in warm water at 60 ° C. for 3 minutes, washed with water and dried. A cellophane adhesive tape was attached to the obtained electroless gold plating evaluation substrate, and the state when peeled off was observed.
○: No abnormality at all.
X: Some peeling was observed.

(PCT resistance) The test substrate was allowed to stand in water at 121 ° C. and 2 atm for 96 hours, and after confirming that there was no abnormality in appearance, a peel test using a cellophane tape was performed and evaluated according to the following criteria.
○ ··· There is no abnormality in the appearance of the coating film, and there is no swelling or peeling × ·········

(Thermal shock resistance) The test piece was subjected to thermal history with -55 ° C / 30 minutes and 125 ° C / 30 minutes as one cycle, and after 1000 cycles, the test piece was observed with a microscope and evaluated according to the following criteria.
○ ·············································································

Table 1
Examples Comparative examples
1 2 1
Alkaline aqueous solution-soluble resin (A) solution A-1 46.55 46.55 46.55
Cross-linking agent (B)
DPHA * 1 6.06 6.06 6.06
Photopolymerization initiator (C)
Irgacure 907 * 2 4.54 4.54 4.54
DETX-S * 3 0.91 0.91 0.91
Curing agent (D)
D-1 17.62
D-2 17.62
NC-3000 17.62
Thermosetting catalyst Melamine 0.76 0.76 0.76
Filler Barium sulfate 24.22 24.22 24.22
Phthalocyanine blue 0.61 0.61 0.61
Additive BYK-354 * 4 0.39 0.39 0.39
KS-66 * 5 1.21 1.21 1.21
Solvent CA * 6 4.54 4.54 4.54

* 1 Nippon Kayaku: Dipentaerythritol hexaacrylate * 2 Ciba Specialty Chemicals: 2-Methyl- (4- (methylthio) phenyl) -2-morpholino-1-propane * 3 Nippon Kayaku: 2, 4 -Diethylthioxanthone * 4 By Big Chemie: Leveling agent * 5 By Shin-Etsu Chemical: Antifoaming agent * 6: Carbitol acetate

Table 2
Example 1 Example 2 Comparative Example 1
Evaluation item Thermal stability 70 minutes 70 minutes 30 minutes tackiness ○ ○ ○
Developability ○ ○ ○
Resolution ○ ○ ○
Light sensitivity 8 8 7
Surface gloss ○ ○ ○
Flame resistance ○ ○ ○
Board sled ○ ○ ○
Flexibility ○ ○ ○
Adhesiveness ○ ○ ○
Pencil hardness 6H 6H 6H
Solvent resistance ○ ○ ○
Acid resistance ○ ○ ○
Heat resistance ○ ○ ○
Gold plating resistance ○ ○ ○
PCT resistance ○ ○ ○
Thermal shock resistance ○ ○ ○

Example 3: Preparation of Dried Film 54.44 g of resin in which the solvent of the alkaline water-soluble resin solution (A-1) described in Synthesis Example 1 was changed to propylene glycol monomethyl ether, DPCA-60 (trade name) as a crosslinking agent : Nippon Kayaku Co., Ltd.) 3.54 g, Irgacure 907 (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator, 4.72 g and Kayacure DETX-S (manufactured by Nippon Kayaku Co., Ltd.) 0.47 g 14.83 g of the epoxy resin (D-1) obtained in Synthesis Example 3 as a curing agent, 1.05 g of melamine as a thermosetting catalyst, and 20.95 g of methyl ethyl ketone as a concentration adjusting solvent, and kneaded uniformly in a bead mill To obtain a resist resin composition.
The obtained composition was uniformly applied to a polyethylene terephthalate film as a support film by a roll coating method, passed through a hot air drying furnace at a temperature of 70 ° C., and a resin layer having a thickness of 30 μm was formed. A polyethylene film to be a protective film was attached to obtain a dry film. The obtained dry film was applied to a polyimide printed circuit board (copper circuit thickness: 12 μm, polyimide film thickness: 25 μm) using a heating roll at a temperature of 80 ° C., and a resin layer was attached to the entire surface of the substrate while peeling off the protective film. Next, ultraviolet rays were irradiated through a mask on which a circuit pattern was drawn using an ultraviolet exposure device (Oak Manufacturing Co., Ltd., model HMW-680GW). Thereafter, spray development was performed with a 1% aqueous sodium carbonate solution to remove the resin in the non-ultraviolet irradiated area. After washing with water and drying, the printed circuit board was subjected to a heat curing reaction in a hot air drier at 150 ° C. for 60 minutes to obtain a cured film. About the obtained cured product, in the same manner as in the above test, photosensitivity, surface gloss, flame retardancy, substrate warpage, flexibility, adhesion, pencil hardness, solvent resistance, acid resistance, heat resistance, gold plating resistance A test was conducted. The results are shown in Table 3.

Table 3
Example 3
Evaluation item developability ○
Resolution ○
Light sensitivity 8
Surface gloss ○
Flame resistance ○
Substrate sled ○
Flexibility ○
Adhesion ○
Pencil hardness 6H
Solvent resistance ○
Acid resistance ○
Heat resistance ○
Gold plating resistance ○
PCT resistance ○
Thermal shock resistance ○

  As apparent from the above results, the photosensitive resin composition of the present invention using the aqueous alkaline solution-soluble resin (A) and the crystalline epoxy resin represented by the formula (1) as the curing agent (D) Since it is excellent in stability, the curing reaction does not start even if the drying time after application to the substrate is long, and development is possible even after drying for a long time. Further, the cured product (cured film) of the photosensitive resin composition of the present invention has no tackiness, is highly sensitive, has excellent flame retardancy, flexibility, heat resistance, chemical resistance, gold plating resistance, etc. It is clear that the photosensitive resin composition for a printed circuit board has little warpage even when a thinned substrate is used without causing cracks on the surface of the cured product.

Claims (7)

In the photosensitive resin composition containing the aqueous alkali solution-soluble resin (A), the crosslinking agent (B), the photopolymerization initiator (C), and the curing agent (D), the curing agent (D) is represented by the formula (1).

(In the above formula (1), n represents an average value and is 1.0 to 2.0. R is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and k is 1) Represents 4)
A photosensitive resin composition, which is a crystalline epoxy resin having the following structure. The photosensitive resin composition according to claim 1, wherein the curing agent (D) is an epoxy resin having a softening point or a melting point of 75 to 180 ° C. The photosensitive resin composition according to claim 1 or 2, wherein the curing agent (D) is an epoxy resin having a structure in which R is a hydrogen atom in the formula (1). The curing agent (D) has a structure in which R is a hydrogen atom in the above formula (1), and the total number of moles of benzene rings in which a methylene group is bonded to the p-position with respect to the glycidyl ether group (p- The total number of moles of the benzene ring in which the methylene group is bonded to the o-position with respect to the glycidyl ether group (o-coordination number) is 0.57 ≦ p-coordination number / (p− (Coordination number + o-coordination number) ≦ 0.90, and GPC analysis is an epoxy resin in which the total content of compounds represented by n in the above formula (1) is 1 is 58 to 92%. The photosensitive resin composition of Claims 1-3 characterized by the above-mentioned. The photosensitive resin composition according to claim 1 or 2, wherein the curing agent (D) contains a compound represented by the formula (2).

An aqueous alkaline solution-soluble resin (A) is obtained by reacting an epoxy compound (a) having two or more epoxy groups in the molecule with a monocarboxylic acid compound (b) having an ethylenically unsaturated group in the molecule. The photosensitive resin composition according to claim 1, which is a reaction product of an epoxycarboxylate compound and a polybasic acid anhydride (c). The photosensitive resin composition according to claim 6, wherein the epoxy compound (a) having two or more epoxy groups in the molecule is represented by the formula (3).

(In the above formula (3), p is an integer of 1 to 3, m is an average value and is 1.0 to 5.0, and R ′ is a hydrogen atom or an alkyl having 1 to 4 carbon atoms. Each R ′ may be the same as or different from each other, s represents an integer of 1 to 4, and t represents an integer of 1 to 3.)