JP4899349B2 - Resin composition for solder resist ink - Google Patents

Description

  The present invention relates to a resin composition for a solder resist ink, which has a good re-solubility with a dilute alkaline aqueous solution and can provide a cured coating film having excellent durability under high temperature and high humidity conditions.

  Epoxy acrylate resins, also called unsaturated epoxy ester resins or vinyl ester resins, have superior heat resistance, chemical resistance, adhesion, and mechanical properties compared to other acrylic oligomers, so various coating materials, structural materials, and wiring boards It is widely used as the main component of solder resist inks.

  As this solder resist ink, a finer pattern is desired as the amount of substrate information increases, and a solder resist ink by a photolithography method is used. Photoengraving methods include a solvent development type that develops unexposed area ink with a solvent and a dilute alkaline solution development type that develops with a dilute alkaline solution, but due to cost and solvent pollution problems, a dilute alkaline solution development type. Has become the mainstream.

  The solder resist ink used in the dilute alkali development type is a so-called acid pendant solution in which a carboxyl group is converted to a pendant by reacting an acid anhydride with a hydroxyl group of an epoxy acrylate resin obtained by reacting an epoxy resin and acrylic acid. Type epoxy acrylate resin is the main component.

  By the way, when a resin having a carboxyl group, such as the acid pendant-type epoxy acrylate resin, is used as a main component of the solder resist ink, the carboxyl in the resin is improved in order to improve the water resistance and electrical properties of the obtained cured coating film. It is common practice to block groups. This blocking of the carboxyl group can be carried out, for example, by containing an epoxy resin in the solder resist ink and performing post-heating at 120 to 130 ° C. after irradiation with ultraviolet rays or irradiation with ultraviolet rays. Thereby, the crosslinking density of the coating film obtained can be improved and a tough coating film can also be formed. However, the coating film obtained by using a solder resist ink in which an epoxy resin is blended with an acid-pendant-type epoxy acrylate resin is not sufficiently durable under high temperature and high humidity conditions. For this reason, a voltage is applied under high temperature and high humidity conditions, and as a result, migration between the positive electrode and the cathode occurs, and the electrical characteristics and the like are ultimately deteriorated by energization between the electrodes. For this reason, a solder resist ink excellent in durability under high temperature and high humidity conditions is desired.

  In order to obtain a solder resist ink having excellent durability under high temperature and high humidity conditions, for example, an amine compound having two or more amino groups in one molecule is reacted with glycidyl methacrylate, and a polybasic acid anhydride is further reacted. A resin composition for solder resist ink containing an obtained active energy ray-curable resin, a photopolymerization initiator, and an epoxy resin is disclosed (for example, see Patent Document 1). However, the cured coating film obtained using the solder resist ink containing the resin composition does not have sufficient re-solubility in a dilute alkaline solution. The active energy ray-curable resin used in the resin composition can be obtained by a reaction between an amine compound and an epoxy group in glycidyl methacrylate. There is also a very difficult problem.

Japanese Patent Laid-Open No. 2001-278952

  An object of the present invention is to provide a resin composition for a solder resist ink that is excellent in durability under high-temperature and high-humidity conditions and from which a cured coating film having good re-solubility in a dilute alkaline solution can be obtained. .

As a result of intensive studies on the above problems, the present inventors have determined that the acid pendant epoxy acrylate resin has a molar ratio (a / b) of acrylic acid (a) and methacrylic acid (b) of 5/95 to 35/35. Solder resist ink containing what is obtained by reacting polycarboxylic acid anhydride with epoxy acrylate resin obtained by reacting acrylic acid-based mixture and polyfunctional epoxy resin (c) in the range of / 65 The cured coating film obtained using the resin composition for use in the present invention has been found to be excellent in durability under high temperature and high humidity conditions, good resolubility in a dilute alkaline solution, etc. It was.

That is, the present invention is a resin composition for a solder resist ink containing an acid pendant type epoxy acrylate resin and a photopolymerization initiator, and the acid pendant type epoxy acrylate resin comprises acrylic acid (a) and methacrylic acid (b ) In the range of 5/95 to 35/65 in a molar ratio (a / b) to the epoxy acrylate resin obtained by reacting the polyfunctional epoxy resin (c) with polycarboxylic acid The present invention provides a resin composition for a solder resist ink, which is obtained by reacting an acid anhydride.

  By using the resin composition for solder resist ink of the present invention, a cured coating film having excellent durability under high temperature and high humidity conditions can be obtained. Further, this cured coating film has good re-solubility in a dilute alkaline solution. Furthermore, the solder resist ink using the resin composition for solder resist ink of the present invention is excellent in curability and developability, and the resin composition for solder resist ink of the present invention can be applied to various coating materials, adhesives, inks and the like. It can be preferably used.

  For the preparation of the acid pendant type epoxy acrylate resin used in the present invention, an acrylic acid containing acrylic acid (a) and methacrylic acid (b) in a molar ratio (a / b) of 3/97 to 45/55. An epoxy acrylate resin obtained by reacting an acid mixture with a polyfunctional epoxy resin (c) is required. Epoxy acrylate obtained by reacting acrylic acid-based mixture having acrylic acid (a) and methacrylic acid (b) content of less than 3/97 in molar ratio (a / b) with polyfunctional epoxy resin (c) An acid pendant type epoxy acrylate resin prepared using a resin is not preferable because it is difficult to obtain a solder resist ink having good resolubility with a dilute aqueous alkali solution. Epoxy acrylate obtained by reacting acrylic acid-based mixture with acrylic acid (a) and methacrylic acid (b) in a molar ratio (a / b) exceeding 45/55 and polyfunctional epoxy resin (c) An acid pendant type epoxy acrylate resin prepared using a resin is not preferable because it is difficult to obtain a solder resist ink having sufficient resistance to a cured coating film under high temperature and high humidity conditions. The molar ratio (a / b) is preferably in the range of 5/95 to 40/60, and more preferably in the range of 5/95 to 35/65.

  As an epoxy acrylate resin, an epoxy acrylate resin (D) obtained by reacting acrylic acid (a) with a polyfunctional epoxy resin (c), a methacrylic acid (b) and a polyfunctional epoxy resin (c) are reacted. The acid pendant type epoxy obtained by using the epoxy acrylate resin obtained by mixing the epoxy acrylate resin (E) obtained by mixing the epoxy acrylate resin (E) at a weight ratio (D) / (E) of 5/95 to 50/50. When the present inventors examined resist inks containing acrylates, it was difficult to obtain a cured coating film that was excellent in durability under high-temperature and high-humidity conditions and had good re-solubility in a dilute alkaline solution. It was.

  In addition to acrylic acid (a) and methacrylic acid (b), these dimer acids, trimer acids and the like may be used together with acrylic acid (a) and methacrylic acid (b) as unsaturated carboxylic acids.

  Furthermore, unsaturated monobasic acid anhydrides such as anhydrous (meth) acrylic acid can be used in combination with acrylic acid (a) and methacrylic acid (b). Examples of anhydrous (meth) acrylic acid include (meth) acrylic acid by reacting an acyl halide of (meth) acrylic acid with an alkali metal salt of (meth) acrylic acid, or in the presence of a dehydrating agent such as thionyl chloride or phosphoryl chloride. It can be prepared from an acid. Moreover, you may prepare by using together the dimer acid of a (meth) acrylic acid, a trimer acid, or an unsaturated monobasic acid, a saturated monobasic acid.

  Moreover, what was obtained by reaction of the compound which has an ethylenically unsaturated double bond and a hydroxyl group, and an acid anhydride can be used as anhydrous (meth) acrylic acid.

  Examples of the compound having an ethylenically unsaturated double bond and a hydroxyl group include hydroxyalkyl (meta) such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and hydroxycyclohexyl (meth) acrylate. ) Acrylates; trimethylolpropane mono (meth) acrylate, trimethylolpropane diacrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol di (meth) acrylate , Dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) Compound obtained by esterifying polyol such as acrylate and (meth) acrylic acid and having hydroxyl group in the molecule; Epoxy obtained by reacting epoxy compound having epoxy group in molecule and (meth) acrylic acid (Meth) acrylate, a compound having a hydroxyl group and a (meth) acrylate group reacted with a cyclic lactone such as ε-caprolactone, a compound having a hydroxyl group and a (meth) acrylate group, ethylene oxide, propylene oxide, butylene oxide, Examples include compounds obtained by reacting cyclic ether compounds such as tetrahydrofuran.

  Examples of the acid anhydride include maleic anhydride, phthalic anhydride, succinic anhydride, dodecenyl succinic anhydride, tetrahydrophthalic anhydride, 4-methyl-tetrahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, hexa Examples include hydrophthalic acid, trimellitic anhydride, methyl nadic anhydride, itaconic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, and the like.

  The polyfunctional epoxy resin (c) used in the present invention is not particularly limited as long as it has two or more epoxy groups in the molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type Bisphenol type epoxy resins such as epoxy resins; Novolak type epoxy resins such as bisphenol novolak type epoxy resins, cresol novolak type epoxy resins, phenol novolak type epoxy resins, xylenol novolak type epoxy resins; Dicyclopentadiene modified epoxy resins; Naphthalene skeletons Naphthol, binaphthol, and naphthols obtained by epoxidizing these naphthols and their novolak bodies; glycidyl ester type resins of polycarboxylic acids; linear aliphatic epoxies Fatty; Aliphatic epoxy resin; Cycloaliphatic epoxy resin; Alkylene oxide-modified epoxy resin; Ziroc-type epoxy resin; Triglycidyl isocyanurate and its derivatives; Non-glycidyl group containing polyglycidyl (meth) acrylate and glycidyl (meth) acrylate Examples thereof include copolymers of saturated monomers and other unsaturated monomers, and these epoxy resins may be used alone or in combination of two or more depending on the desired performance required. .

  Among these, a novolac type epoxy resin is preferable from the viewpoints of obtaining a cured coating film having excellent heat resistance and hardness and having less stickiness after provisional drying after coating (good tackiness). The novolak type epoxy resin preferably has a number average molecular weight of 700 to 3,000. The softening point is preferably 30 to 120 ° C. Therefore, the novolak type epoxy resin used in the present invention is more preferably a novolak type epoxy resin having a number average molecular weight of 700 to 3000 and a softening point of 30 to 120 ° C. Furthermore, a cresol novolac type epoxy resin is more particularly preferable because a resin composition for resist ink having good storage stability can be obtained.

  The acrylic acid mixture and the polyfunctional epoxy resin (c) are reacted to obtain an epoxy acrylate resin. In this reaction, mixing of the acrylic acid mixture and the polyfunctional epoxy resin (c) prevents odor and skin irritation caused by the remaining acrylic acid (a) and methacrylic acid (b) in the reaction system, and In order to prevent problems such as increase in viscosity and decrease in stability due to excessive epoxy groups, the number of moles (n1) of all epoxy groups in polyfunctional epoxy resin (c), acrylic acid (a), and methacrylic acid It is preferable that the ratio [(n1) / (n2)] to the number of moles (n2) of all carboxyl groups in (b) is 0.8 to 1.2, preferably 0.9 to 1.1. It is more preferable to carry out in such a range.

  A catalyst is used when the acrylic acid-based mixture and the polyfunctional epoxy resin (c) are reacted. A catalyst such as a non-halogen catalyst or a halogen catalyst can be used as the catalyst. Among these, a non-halogen catalyst is preferable.

  Examples of the non-halogen catalyst include tertiary amine catalysts such as triethylamine, trisdimethylaminomethylphenol, and benzyldimethylamine; tetramethylammonium hydroxide; 2-methylimidazole, 2-ethyl-4-methylimidazole, and the like. Imidazole catalysts; Nitrogen compounds catalysts such as diazabiscycloundecene; Triethylphosphine, tri-n-propylphosphine, tri-n-butylphosphine, tri-m-tolylphosphine, tris (2,6-methoxyphenyl) Various catalysts such as phosphine catalysts such as phosphine and triphenylphosphine; phosphonium salt catalysts such as tetra-n-butylphosphonium hydroxide; metal salt catalysts such as chromium naphthenate can be used. Of these, phosphorus catalysts such as phosphine catalysts and phosphonium salt catalysts are preferable, and phosphine catalysts are particularly preferable. The amount of the non-halogen catalyst used is suitably 10 to 10,000 ppm with respect to the total charged amount of acrylic acid (a), methacrylic acid (b) and polyfunctional epoxy resin (c).

  Examples of the halogen-based catalyst include inorganic catalysts such as sodium hydroxide and lithium hydroxide; quaternary ammonium salts such as trimethylbenzylammonium chloride and tetramethylammonium chloride; tetra-n-butylphosphonium bromide and ethyltriphenylphosphonium. Examples thereof include phosphonium salts such as bromide. An appropriate amount of the halogen-based catalyst is 10 to 5,000 ppm with respect to the total charged amount of acrylic acid (a), methacrylic acid (b), and polyfunctional epoxy resin (c).

  When reacting an acrylic acid-based mixture with a polyfunctional epoxy resin, an organic solvent is used to improve the stirring efficiency during the reaction and to improve the application suitability such as handling properties, coating properties, and printability. It is preferable to react. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; cellosolves such as cellosolve and butylcellosolve; carbitols such as carbitol and butylcarbitol; ethyl acetate and acetic acid Acetic esters such as butyl, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate; and other alkylene alcohols, alkylene glycols, alkylene polyols (eg, propylene glycol) produced from alkylene oxides Alkyl esters of these alkylene polyols, ethers of alkyl ethers, esters and the like can be mentioned.

  When reacting an acrylic acid-based mixture with a polyfunctional epoxy resin, the reaction system is agitated in an atmosphere having an oxygen concentration of 2 to 12%, and the risk of explosion of the reaction solvent and the like is reduced. While avoiding this, it is possible to suppress polymerization of acrylic acid (a) and methacrylic acid (b), and it is favorable in terms of preventing side reactions and gelation accompanying oxidation of the resin and improving the color. Moreover, when performing reaction, it is preferable to carry out in presence of a stirring apparatus, and it is preferable to carry out with the apparatus which is excellent in stirring efficiency.

  The reaction temperature and reaction time when the acrylic acid-based mixture and the polyfunctional epoxy resin (c) are reacted are increased so that the reaction rate is increased and the catalyst is deactivated so as not to remain in the reaction system as an active species. In order to maintain good storage stability and development stability of the development resist composition, and to prevent the generated resin and reaction solvent from causing coloring and abnormal molecular weight distribution due to side reactions such as oxidation. In addition, the reaction temperature is preferably 80 to 160 ° C. while considering the progress of the reaction. The reaction time at this time is preferably in the range of 1 to 30 hours for the same reason. Further, since the reaction rate increases as the reaction temperature increases, it is necessary to adjust the reaction temperature in order to keep the reaction rate appropriate.

  Determination of the completion of the reaction between the acrylic acid-based mixture and the polyfunctional epoxy resin (c) when producing the epoxy acrylate resin can be made by analyzing the acid value, epoxy equivalent, infrared spectrum, etc. in the system. it can.

  The acid value of the epoxy acrylate resin obtained by reacting the acrylic acid mixture with the polyfunctional epoxy resin (c) is preferably 5 mg KOH / g or less in terms of solid content from the viewpoint of stability, odor, and safety. Of these, 3 mgKOH / g or less is more preferable. The epoxy equivalent is 6000 g / eq. In terms of solid content in order to keep the stability of the produced resin good. Or more, preferably 10,000 g / eq. That's it.

  The acid pendant type epoxy acrylate resin used in the present invention is obtained by reacting a polycarboxylic acid anhydride with an epoxy acrylate resin obtained by reacting the acrylic acid-based mixture with the polyfunctional epoxy resin (c).

  When preparing the epoxy acrylate resin, a hydroxyl group is formed in the reaction of the acrylic acid mixture and the polyfunctional epoxy resin (c). A ring-opening esterification reaction of the acid anhydride contained in the polycarboxylic acid anhydride occurs with respect to this hydroxyl group, and the carboxyl group can be introduced into the resin. The ring-opening esterification reaction at this time can be performed in the range of 50 to 140 ° C.

  Said polycarboxylic anhydrides, for example maleic anhydride, phthalic anhydride, succinic anhydride, dodecenyl succinic anhydride, tetrahydrophthalic anhydride, 4-methyl-tetrahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, anhydrous Hexahydrophthalic acid, trimellitic anhydride, hettic anhydride, methyl nadic anhydride, itaconic anhydride, benzophenone tetracarboxylic anhydride, etc. are preferable, but dicarboxylic anhydride is preferably used under high temperature and high humidity conditions. This is preferable because it provides a solder resist ink that is excellent in durability and can provide a cured coating film with good resolubility with a dilute aqueous alkali solution.

  The acid value of the acid pendant type epoxy acrylate resin obtained by reacting an epoxy acrylate resin with a polycarboxylic acid anhydride is preferably 30 to 150 mgKOH / g in terms of solid content as an acid value that can be developed with an aqueous alkali solution. ˜130 mg KOH / g is more preferred.

  By performing the reaction between the epoxy acrylate resin and the polycarboxylic acid anhydride in the presence of an antioxidant, an acid pendant type epoxy acrylate resin can be more stably produced. Examples of the antioxidant include hydroquinone, methylhydroquinone, trimethylhydroquinone, tertiarybutylhydroquinone, 2,6-ditertiarybutyl-4-methoxyphenol, copper salt, phenothiazine; triethylene glycol-bis {3- (3- t-butyl-5-methyl-4-hydroxyphenyl) propionate}, 1,6-hexanediol-bis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, 2,4- Bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, pentaerythrityl-tetrakis {3- (3,5-di-t -Butyl-4-hydroxyphenyl) propionate}, 2,2-thio-diethylenebis {3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate}, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N hexamethylenebis (3,5-di-) -T-butyl-4-hydroxy-hydroxycinnamamide), 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6- Tris (3,5-di-t-butyl-4-hydroxyphenyl) benzene, bis (3,5-di-t-butyl-4-hydroxyphenylphosphonate ethyl) calcium, tris- (3,5-di- hindered phenolic antioxidants such as t-butyl-4-hydroxyphenyl) -isocyanurate; cresol, phenolic antioxidants; hindered doors Emissions-based stabilizers; phosphorous acid, phosphorous acid esters, phosphorous acid diesters and the like. Among these, the antioxidant containing a phenolic hydroxyl group is preferable.

  The amount of the antioxidant used is preferably in the range of 50 PPm to 2% with respect to the charged weight of the reaction system in order to obtain a sufficient polymerization prevention effect and to prevent curing failure in active energy ray curing.

  The acid pendant type epoxy acrylate resin used in the present invention is obtained by reacting a polycarboxylic acid anhydride with an epoxy acrylate resin obtained by reacting an acrylic acid-based mixture and a polyfunctional epoxy resin (C) as described above. At this time, when the epoxy acrylate resin and the polycarboxylic acid anhydride are reacted with each other, the respective amounts can be appropriately adjusted to prepare an acid pendant type epoxy acrylate resin containing a hydroxyl group. Then, the acid pendant type epoxy acrylate resin containing a hydroxyl group and the acid pendant type epoxy acrylate resin containing an isocyanate group are reacted to introduce a urethane bond into the resin, and the acid pendant type epoxy acrylate resin is polyfunctionalized. It is also possible to modify the photocuring sensitivity, physical properties and the like.

  Obtained by reacting an isocyanate group of the isocyanate group-containing acid pendant type epoxy acrylate resin with an acrylic acrylate resin obtained by reacting an acrylic acid mixture and a polyfunctional epoxy resin (C) with a polycarboxylic acid anhydride. Various urethanization catalysts can be used for the reaction with the hydroxyl group of the acid pendant type epoxy acrylate resin. The ratio of the hydroxyl group to the isocyanate group is preferably 0.05 to 0.9 mol of the isocyanate group with respect to 1 mol of the hydroxyl group in terms of sensitivity improvement, reactivity, application suitability, and development solubility. It is especially preferable that it is 0.05-0.5 mol.

  Examples of the isocyanate group-containing acid pendant type epoxy acrylate resin include isocyanate alkyl (meth) acrylates such as isocyanate ethyl (meth) acrylate.

  The isocyanate group-containing acid pendant type epoxy acrylate resin is composed of a polymerizable unsaturated group having an acrylate group and a hydroxyl group at the terminal and a compound having a hydroxyl group (a1) and a polyisocyanate compound having two or more isocyanate groups in the molecule. It can also be obtained by reacting with (a2).

  Examples of the compound (a1) having a polymerizable unsaturated group and a hydroxyl group at the terminal include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meta). ) Acrylate, 2- (meth) acryloyloxyethyl-2-hydroxyethylphthalic acid, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, 3-acryloyloxyglycerin mono (meth) acrylate, 2-hydroxybutyl (Meth) acrylate, 2-hydroxy-1- (meth) acryloxy-3- (meth) acryloxypropane, glycerin di (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono ( Data) acrylate, poly ε- caprolactone mono (meth) acrylate, polytetramethylene glycol mono (meth) acrylate.

  As the polyisocyanate compound (a2), for example, an isocyanate compound, a polyisocyanate in which an isocyanate compound is isocyanurated, a polyisocyanate formed into a burette, a polyisocyanate adducted with a polyol, and the like can be used. , For example, various alicyclic diisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate; various aliphatic diisocyanate compounds such as hexamethylene diisocyanate, lysine diisocyanate; hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (hydrogenated diphenyl Tan-4,4'-diisocyanate) various compounds such as and the like.

  The resin composition for solder resist ink of the present invention is characterized by containing the acid pendant type epoxy acrylate resin and a photopolymerization initiator. Examples of the photopolymerization initiator include 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid ester, alkoxyacetophenone, benzophenone and benzophenone derivatives, alkyl benzoylbenzoate, bis (4-dialkylaminophenyl) ketone, benzyl and benzyl. Derivatives, benzoin and benzoin derivatives, benzoin alkyl ethers, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenoylphosphine oxide, 2-methyl-1- [4- (Methylthio) phenyl] -2-morpholinopropane-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1; acetophenone, 2,2-dimeth Acetophenones such as cis-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1- Anthraquinones such as chloroanthraquinone and 2-aluminumanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone; acetophenone dimethyl ketal and benzyldimethyl ketal And ketals or xanthones.

  The amount of the photopolymerization initiator used is usually in the range of 0.2 to 30 parts by weight, preferably 2 to 20 parts by weight with respect to 100 parts by weight of the resin solid content, and is used alone or in combination of two or more. You can also.

  In order to prepare a solder resist ink using the resin composition for a solder resist ink of the present invention, for example, the resin composition for a solder resist ink of the present invention and a photopolymerization initiator are essential, and further an organic solvent as necessary. , Photopolymerizable monomers, fillers, colorants, thermal polymerization inhibitors, thickeners, antifoaming agents, silane coupling agents and the like may be mixed.

  Furthermore, it is preferable to add a polyfunctional epoxy resin that can react with the carboxyl group of the acid pendant type epoxy acrylate resin after UV exposure and development. Such a polyfunctional epoxy resin is preferably an epoxy compound having at least two epoxy groups in one molecule, for example, bisphenol type epoxy resins such as bisphenol A, bisphenol F, and bisphenol S; these bisphenol novolak type and cresol novolak type. Various novolac epoxy resins such as phenol novolac type and xylenol novolac; dicyclopentadiene-modified epoxy resin; naphthol having a naphthalene skeleton; Polycarboxylic acid glycidyl ester resin; linear aliphatic epoxy resin; alicyclic epoxy resin; triglycidyl isocyanurate and its derivatives; polyglycidyl (meth) Examples include copolymers of glycidyl group-containing unsaturated monomers such as acrylate and glycidyl (meth) acrylate, and other unsaturated monomers. Depending on the desired performance, these epoxy resins may be used alone. Two or more types may be mixed and used. The preferable use range is 30 to 300 parts by weight, preferably 30 to 300 parts by weight, and more preferably 50 to 200 parts by weight with respect to 100 parts by weight of the solid content of the acid pendant type epoxy acrylate resin.

  Furthermore, amine compounds such as melamine, imidazole compounds, dialkylureas, carboxylic acids, phenols, methylol group-containing compounds, etc. for the purpose of accelerating the reaction, as long as the effects are not impaired when a polyfunctional epoxy resin is added By using a small amount of various epoxy curing accelerators and post-heating the coating film, the polymerization of the photocuring component is accelerated, the reaction of the carboxyl group of the epoxy compound and the acid pendant epoxy acrylate, and the reaction between the epoxy compounds. Various physical properties of the resulting resist film can also be improved.

  Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; cellosolves such as cellosolve and butylcellosolve; carbitols such as carbitol and butylcarbitol; Acetic esters such as butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate; and other alkylene alcohols, alkylene glycols, alkylene polyols (eg, propylene glycol) produced from alkylene oxides And alkyl esters of these alkylene polyols, ethers of alkyl ethers, esters, and the like.

  The polymerizable monomer can be added for the purpose of improving the physical properties of the cured film, improving the curability, improving the coating suitability, and the like. Various photopolymerizable vinyl monomers can be used as the photopolymerizable monomer. Typical examples include β-hydroxyethyl acrylate, β-hydroxypropyl acrylate, glycidyl acrylate, and β-hydroxyethyl acryloyl phosphate. , Dimethylaminoethyl acrylate, diethylaminoethyl acrylate; ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol di Acrylate, trimethylolpropane diacrylate; trimethylolpropane Reacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tris (2-acryloyloxyethyl) isocyanurate, or each methacrylate for the acrylate ;

  Mono-, di-, tri- or higher polyesters of polybasic acids and hydroxyalkyl (meth) acrylates; ethylenically unsaturated double bonds such as bisphenol A type epoxy acrylate, novolac type epoxy acrylate, urethane acrylate Examples thereof include monomers and oligomers.

  The photopolymerizable vinyl monomer and the organic solvent are used alone or as a mixture of two or more, and the preferred amount of use is 30 to 300 parts by weight, more preferably 50 to 200 parts by weight with respect to 100 parts by weight of the resin solid content. It is.

  Examples of the filler include barium sulfate, silicon oxide, talc, clay, calcium carbonate, and the like.

  Examples of the colorant include phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, and the like.

  Examples of the thermal polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, and phenothiazine.

  Examples of the thickener include finely divided silica, organic bentonite, and montmorillonite.

  Examples of the antifoaming agent include silicone-based antifoaming agents, fluorine-based antifoaming agents, and polymer-based antifoaming agents.

  Examples of the silane coupling agent include imidazole silane coupling agents, thiazole silane coupling agents, and triazole silane coupling agents.

  The solder resist ink containing the resin composition for solder resist ink of the present invention is applied to the entire surface by, for example, screen printing, roll coater method, curtain coater method, spray coater method, etc. After irradiation and curing of the necessary part, the unexposed part is dissolved away with a dilute aqueous alkali solution, and further post-curing with heat can be applied to form the intended film.

  The active energy ray is a general term for ionizing radiation, light, and the like, such as electron beam, α ray, γ ray, X ray, neutron ray, and ultraviolet ray.

  When ultraviolet rays are used as an irradiation light source for curing the active energy ray resin composition, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, etc. are suitable, and other laser beams, etc. Can also be used as an active energy ray for curing.

  The present invention will be described more specifically with reference to synthesis examples, examples and comparative examples. In the examples, all parts and% are based on weight unless otherwise specified.

Synthesis Example 1 (Preparation of acid pendant type epoxy acrylate resin)
Into a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 74.3 g of ethyl carbitol acetate was put, and ortho-cresol novolac type epoxy resin Epicron N-680 (manufactured by Dainippon Ink & Chemicals, Inc., epoxy) Equivalent 212) 212 g (1.0 mol) was dissolved, and 0.15 g of MQ (methylhydroquinone) was added as a polymerization inhibitor, followed by 81.7 g (0.95 mol) of methacrylic acid and 3.6 g (0.05 mol) of acrylic acid. Then, 1.49 g of triphenylphosphine was added, and esterification was performed at 105 ° C. for 14 hours. When the acid value was 0.9 mgKOH / g (solid content conversion: 1.1 mgKOH / g) and the epoxy equivalent was 9500 g / eq (g / equivalent), 135.1 parts of ethyl carbitol acetate, tetrahydrophthalic anhydride 91.2 Part (0.6 mol) was added and reacted at 100 ° C. for 5 hours. A light yellow acid pendant epoxy acrylate resin having an acid value of 56.5 mgKOH / g (solid content value 86.9 mgKOH / g) and a solid content of 65%. A solution (A-1) was obtained.

Synthesis example 2 (same as above)
Into a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 74.2 g of ethyl carbitol acetate was added, 212 g (1 mol) of Epicron N-680 was dissolved, and 0.15 g of MQ was added as a polymerization inhibitor. Thereafter, 77.4 g (0.9 mol) of methacrylic acid, 7.2 g (0.1 mol) of acrylic acid and 1.49 g of triphenylphosphine were added, and an esterification reaction was performed at 120 ° C. for 10 hours. When the acid value became 0.7 mg KOH / g (solid content conversion: 0.9 mg KOH / g) and the epoxy equivalent reached 10800 g / eq (g / equivalent), 134.8 parts ethyl carbitol acetate, 91.6 tetrahydrophthalic anhydride 91.6 Part (0.6 mol) was added and reacted at 100 ° C. for 5 hours. A light yellow acid pendant epoxy acrylate resin having an acid value of 56.4 mgKOH / g (solid content value 86.8 mgKOH / g) and a solid content of 65%. A solution (A-2) was obtained.

Synthesis example 3 (same as above)
In a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, put 73.6 g of ethyl carbitol acetate, dissolve 212 g (1 mol) of Epicron N-680, and add 0.15 g of MQ as a polymerization inhibitor. Thereafter, 64.5 g (0.75 mol) of methacrylic acid, 18.0 g (0.25 mol) of acrylic acid and 1.49 g of triphenylphosphine were added, and an esterification reaction was performed at 110 ° C. for 12 hours. When the acid value was 0.6 mgKOH / g (converted to solid content: 0.8 mgKOH / g) and the epoxy equivalent was 12100 g / eq (g / equivalent), 134.3 parts of ethyl carbitol acetate, tetrahydrophthalic anhydride 91.2 A light yellow acid pendant type epoxy acrylate resin solution having an acid value of 56.9 mgKOH / g (solid content value 87.5 mgKOH / g) and a solid content of 65%. (A-3) was obtained.

Synthesis example 4 (same as above)
In a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, put 73.1 g of ethyl carbitol acetate, dissolve 212 g (1 mol) of Epicron N-680, and add 0.15 g of MQ as a polymerization inhibitor. Thereafter, 55.9 g (0.65 mol) of methacrylic acid, 25.9 g (0.35 mol) of acrylic acid and 1.49 g of triphenylphosphine were added, and an esterification reaction was performed at 110 ° C. for 12 hours. When an acid value of 0.23 mg KOH / g (converted to solid content: 0.4 mg KOH / g) and an epoxy equivalent of 13300 g / eq (g / equivalent) were reached, 133.7 parts of ethyl carbitol acetate, tetrahydrophthalic anhydride 91.2 Part (0.6 mol) was added and reacted at 100 ° C. for 4 hours. A light yellow acid pendant type epoxy acrylate resin having an acid value of 57.3 mgKOH / g (solid content value 88.2 mgKOH / g) and a solid content of 65%. A solution (A-4) was obtained.

Synthesis example 5 (same as above)
In a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, put 73.1 g of ethyl carbitol acetate, dissolve 212 g (1 mol) of Epicron N-680, and add 0.15 g of MQ as a polymerization inhibitor. Thereafter, 51.6 g (0.6 mol) of methacrylic acid, 28.8 g (0.4 mol) of acrylic acid and 1.49 g of triphenylphosphine were added, and an esterification reaction was performed at 110 ° C. for 12 hours. When the acid value became 0.3 mg KOH / g (solid content conversion: 0.4 mg KOH / g) and the epoxy equivalent reached 12700 g / eq (g / equivalent), 133.7 parts of ethyl carbitol acetate, tetrahydrophthalic anhydride 91.2 A light yellow acid pendant type epoxy acrylate resin solution having an acid value of 57.5 mgKOH / g (solid content value 88.5 mgKOH / g) and a solid content of 65%. (A-5) was obtained.

Synthesis example 6 (same as above)
Into a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 68.6 g of ethyl carbitol acetate was placed, and ortho-cresol novolac type epoxy resin Epicron N-770 (manufactured by Dainippon Ink & Chemicals, Inc., epoxy) Equivalent 192) After dissolving 192 g (1 mol) and adding 0.15 g of MQ as a polymerization inhibitor, 64.5 g (0.75 mol) of methacrylic acid, 18.0 g (0.25 mol) of acrylic acid, triphenylphosphine 1 .4 g was added and the esterification reaction was carried out at 110 ° C. for 13 hours. When the acid value was 0.6 mgKOH / g (converted to solid content: 0.6 mgKOH / g) and the epoxy equivalent was 12000 g / eq (g / equivalent), 128.3 parts of ethyl carbitol acetate, tetrahydrophthalic anhydride 91.2 Part (0.6 mol) was added and the reaction was carried out at 100 ° C. for 5 hours. The acid value was 60.9. A pale yellow acid pendant epoxy acrylate resin solution (A-6) having a solid content of 65% was obtained at mg KOH / g (solid content value 93.7 mg KOH / g).

Synthesis Example 7 (Preparation of acid pendant type epoxy acrylate resin for comparison)
In a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 74.5 g of ethyl carbitol acetate was added to dissolve 212 g (1 mol) of Epicron N-680, and 0.15 g of MQ was added as a polymerization inhibitor. Thereafter, 86 g (1 mol) of methacrylic acid and 1.49 g of triphenylphosphine were added, and an esterification reaction was performed at 120 ° C. for 9 hours. When the acid value was 0.9 mg KOH / g (solid content conversion: 1.1 mg KOH / g) and the epoxy equivalent was 9800 g / eq (g / equivalent), 135.3 parts of ethyl carbitol acetate and 91.2 tetrahydrophthalic anhydride were obtained. Part (0.6 mol) was added and reacted at 100 ° C. for 6 hours, and the acid value was 56.5 mgKOH / g (solid content value 86.9 mgKOH / g) and the solid content was 65% solid yellowish acid pendant for comparison. An epoxy acrylate resin solution (B-1) was obtained.

Synthesis example 8 (same as above)
In a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 72.8 g of ethyl carbitol acetate was added to dissolve 212 g (1 mol) of Epicron N-680, and 0.15 g of MQ was added as a polymerization inhibitor. Thereafter, 43.0 g (0.5 mol) of methacrylic acid, 36.0 g (0.5 mol) of acrylic acid and 1.49 g of triphenylphosphine were added, and an esterification reaction was performed at 110 ° C. for 12 hours. When the acid value reached 0.5 mgKOH / g (converted to solid content: 0.6 mgKOH / gKOH-mg / g) and epoxy equivalent of 12100 g / eq (g / equivalent), 133.2 parts of ethyl carbitol acetate, tetrahydrophthalic anhydride 91.2 parts (0.6 mol) of acid was added and reacted at 100 ° C. for 5 hours. A light yellow acid pendant epoxy acrylate resin solution for comparison (B-2) having a acid value of 57.1 mgKOH / g (solid content value: 87.8 mgKOH / g) and a solid content of 65% was obtained.

Synthesis example 9 (same as above)
In a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 72.8 g of ethyl carbitol acetate was added to dissolve 212 g (1 mol) of Epicron N-680, and 0.15 g of MQ was added as a polymerization inhibitor. Thereafter, 21.5 g (0.25 mol) of methacrylic acid, 56.3 g (0.75 mol) of acrylic acid and 1.49 g of triphenylphosphine were added, and an esterification reaction was performed at 110 ° C. for 10 hours. When the acid value was 0.3 mg KOH / g (solid content conversion: 0.4 mg KOH / g) and the epoxy equivalent was 14200 g / eq (g / equivalent), 132.2 parts of ethyl carbitol acetate, tetrahydrophthalic anhydride 91.2 Part (0.6 mol) was added and the reaction was carried out at 100 ° C. for 5 hours, and the acid value was 57.7 mgKOH / g (solid content value 88.8 mgKOH / g) and the solid content was 65% solid yellow light pendant for comparison. An epoxy acrylate resin solution (B-3) was obtained.

Synthesis example 10 (same as above)
In a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 71.0 g of ethyl carbitol acetate was added, 212 g (1 mol) of Epicron N-680 was dissolved, and 0.15 g of MQ was added as a polymerization inhibitor. Thereafter, 72.0 g (1.0 mol) of acrylic acid and 1.49 g of triphenylphosphine were added, and an esterification reaction was carried out at 105 ° C. for 14 hours. When the acid value became 0.3 mg KOH / g (solid content conversion: 0.8 mg KOH / g) and the epoxy equivalent reached 10500 g / eq (g / equivalent), 131.2 parts of ethyl carbitol acetate, tetrahydrophthalic anhydride 91.2 Part (0.6 mol) was added and reacted at 100 ° C. for 5 hours, and the acid value was 58.0 mgKOH / g (solid content value: 89.2 mgKOH / g) and the solid content was 65% solid yellow, as a comparative acid pendant type for comparison. An epoxy acrylate resin solution (B-4) was obtained.

Synthesis example 11 (same as above)
In a 1 liter reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 317 parts of Anirix A-15 (manufactured by Mitsui Chemicals Co., Ltd.) is charged, heated to 60 ° C. and dissolved. Thereafter, the temperature is raised to 80 ° C. with stirring to maintain the temperature. Next, 288 parts of glycidyl methacrylate and 0.3 part of methylhydroquinone were charged in this order and reacted at 80 ° C. Gelation occurred after 1 hour from the start of the reaction.

Example 1
Each composition was mixed by the formulation shown in Table 1 and kneaded by a three-roll mill to obtain a resin composition 1 for solder resist ink. A test piece was prepared using the resin composition 1 for solder resist ink. Next, evaluation of the resin composition 1 for resist ink (re-dissolvability, developability, sensitivity, solder heat resistance, adhesion, electric resistance, high temperature and high humidity resistance) was performed using the prepared test piece. Each evaluation method is shown below. The evaluation results are shown in Table 3.

<Evaluation of re-solubility>
Resin ink resin composition 1 was applied to the entire surface of a copper-clad laminate of a glass epoxy base material having a copper foil of 35 μm using a 150-mesh screen to prepare a test piece. This test piece was left in an oven at 80 ° C. for 30 minutes to evaporate the solvent, immersed in a 1% sodium carbonate aqueous solution for 90 seconds and developed, and the solubility of the coating film was visually determined.
A: No coating film is left on the laminate.
○: Almost no coating film remains on the laminate.
Δ: Some coating film remains on the laminate.
X: A coating film remains on a laminated board.

<Development evaluation>
The test piece was prepared in the same manner as in <Evaluation of re-solubility>. This test piece is left in a 90 ° C. dryer for 20 to 70 minutes to evaporate the solvent, immersed in a 1% sodium carbonate aqueous solution for 180 seconds and developed, and the stability during solvent drying is visually determined. did. The performance evaluation was performed according to the following criteria, and a product that was stable for 50 minutes or more was regarded as acceptable.
A: No coating film is left on the laminate.
○: Almost no coating film remains on the laminate.
Δ: Some coating film remains on the laminate.
X: A coating film remains on a laminated board.

<Evaluation of sensitivity>
A test piece was prepared in the same manner as in <Evaluation of re-solubility>. This test piece was allowed to stand in an oven at 80 ° C. for 30 minutes to volatilize the solvent. 2 Place the (Kodak Co.), after irradiation with ultraviolet rays of ^{400mJ / cm 2, 800mJ / cm} 2 using a high pressure mercury lamp, and 180 seconds immersed in a 1% sodium carbonate aqueous solution 30 ° C., at step tablet method Evaluation was performed. The evaluation value indicates the maximum number of remaining steps, and the larger the value, the better the curability (sensitivity). In the irradiation condition of 400 mJ / cm ² , 6 steps or more were accepted, and in the condition of 800 mJ / cm ² , 9 steps or more were accepted.

<Evaluation of solder heat resistance>
Resin ink resin composition 1 is applied to the entire surface of a copper-clad laminate of glass epoxy substrate with a copper foil of 35 μm using a 150 mesh screen, dried at 80 ° C. for 30 minutes, and allowed to cool to room temperature. A negative film was applied to this substrate, and the solder resist pattern was exposed under the condition of an exposure amount of 400 mJ / cm ² , immersed in a 1% sodium carbonate aqueous solution at 30 ° C. for 180 seconds and developed for 180 seconds to obtain a resist pattern. This substrate was cured by heating at 150 ° C. for 60 minutes to obtain an evaluation substrate. A rosin-based flux was applied to the evaluation substrate, immersed in a solder bath set at 260 ° C. in advance, and the flux was washed with denatured alcohol. Then, the resist layer was visually evaluated for swelling / peeling. The judgment criteria are as follows.
○: Even if the immersion for 10 seconds is repeated 3 times or more, peeling is not recognized.
(Triangle | delta): It peels for a while when immersion for 10 seconds is repeated 3 times or more.
X: The resist layer swells and peels off within 3 times for 10 seconds.

<Evaluation of adhesion>
An evaluation board was prepared in the same manner as in <Evaluation of Solder Heat Resistance>. According to the test method of JIS D 0202, this evaluation substrate was cross-cut in a grid pattern, and a peel test with an adhesive tape was performed to evaluate the peeling of the resist layer. The judgment criteria are as follows.
○: No peeling is observed Δ: Only a slight peeling ×: The resist layer is peeling

<Evaluation of electric corrosion resistance>
Resin ink resin composition 1 is applied to the entire surface of the IPC B-25 comb-type electrode substrate using a 150-mesh screen, dried at 80 ° C. for 30 minutes, and allowed to cool to room temperature. A negative film was applied to this substrate, and the solder resist pattern was exposed under the condition of an exposure amount of 400 mJ / cm ² , immersed in a 1% sodium carbonate aqueous solution at 30 ° C. for 180 seconds and developed for 180 seconds to obtain a resist pattern. This substrate was cured by heating at 150 ° C. for 60 minutes to obtain an evaluation substrate. A bias voltage of DC 100 V was applied to the comb-shaped electrode of this evaluation substrate, and 85 ° C., 85% R.D. H. The presence or absence of migration after 200 hours was visually confirmed in a constant temperature and humidity chamber. The judgment criteria are as follows.
○: No change is observed Δ: Only a slight change ×: Migration occurs

<Evaluation of high temperature and high humidity test (PCT resistance)>
Resin ink resin composition 1 is applied to the entire surface of a copper-clad laminate of glass epoxy substrate with a copper foil of 35 μm using a 150 mesh screen, dried at 80 ° C. for 30 minutes, and allowed to cool to room temperature. A negative film was applied to this substrate, and the solder resist pattern was exposed under the condition of an exposure amount of 400 mJ / cm ² , immersed in a 1% sodium carbonate aqueous solution at 30 ° C. for 180 seconds and developed for 180 seconds to obtain a resist pattern. This substrate was cured by heating at 150 ° C. for 60 minutes to obtain an evaluation substrate. This evaluation substrate was treated with a PCT apparatus (TABAI ESPEC HASTSYSTEM TPC-412MD) at 121 ° C. and 2 atm for 100 hours and 200 hours, and then a peel test with an adhesive tape was performed to visually evaluate the state of the cured film.
(Double-circle): The state of a coating film has not changed at all.
○: Either peeling or discoloration of the coating film is slightly observed.
(Triangle | delta): There exists either peeling of a coating film or discoloration.
X: Peeling of the coating film and many discoloration are observed.
XX: All coating films are peeled off.

Examples 2-6 and Comparative Examples 1-7
Resist ink resin compositions 2 to 6 and comparative resist ink resin compositions 1 'to 7' were prepared in the same manner as in Example 1 except that the compositions shown in Tables 1 and 2 were used. Evaluation was carried out in the same manner as in Example 1 except that these resist ink resin compositions were used. Each evaluation method is shown below. The evaluation results are shown in Tables 3 and 4.

Footnotes in Tables 1 and 2 Epicron N-680: Orthocresol novolac epoxy resin (Dainippon Ink Chemical Co., Ltd.)
DPHA: Dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.)
Irgacure 907: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinoaminopropane-1 (photopolymerization initiator manufactured by Ciba Specialty Chemicals)
KS-66: Silicone-based antifoaming agent (manufactured by Shin-Etsu Chemical Co., Ltd.)

Claims (5)

A resin composition for solder resist ink containing an acid pendant type epoxy acrylate resin and a photopolymerization initiator, wherein the acid pendant type epoxy acrylate resin has a molar ratio of acrylic acid (a) and methacrylic acid (b) ( a / b) is reacted with a polycarboxylic acid anhydride to an epoxy acrylate resin obtained by reacting an acrylic acid-based mixture contained in a range of 5/95 to 35/65 with a polyfunctional epoxy resin (c). A resin composition for solder resist ink, which is obtained by   The resin composition for solder resist ink according to claim 1, wherein the polyfunctional epoxy resin (c) is a novolac type epoxy resin. The resin composition for solder resist ink according to claim 2 , wherein the novolac type epoxy resin is a cresol novolac type epoxy resin.   The resin composition for a solder resist ink according to claim 1, wherein the polycarboxylic acid anhydride is a dicarboxylic acid anhydride. Furthermore, the resin composition for solder resist inks of any one of Claims 1-4 containing a polyfunctional epoxy resin.