Photosensitive resin composition, dry film, and printed circuit board having photocured product of photosensitive resin composition

Abstract

The present invention aims to provide a photosensitive resin composition capable of forming a photocured film having excellent alkali developability, gold plating property and other plating properties without impairing high sensitivity to ultraviolet rays. A photosensitive resin composition comprising (A) a carboxyl group-containing photosensitive resin, (B) an antioxidant, (C) a photopolymerization initiator, (D) a reactive diluent and (E) an epoxy compound, wherein the (B) antioxidant comprises at least one compound selected from the group consisting of (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur.

Description

Technical Field

[0001] The present invention relates to a photosensitive resin composition suitable for a coating material, such as an insulating coating material, a dry film having a coating obtained by coating the photosensitive resin composition on a film, and a printed wiring board coated with a photocured product obtained by photocuring the photosensitive resin composition. Background Art

[0002] A conductor circuit pattern of a conductor (e.g., copper foil) is formed on a substrate, and an electronic component is mounted on a pad of the circuit pattern by soldering, and the circuit portion other than the pad is covered with an insulating film, i.e., a solder resist film, as a protective film. As the insulating film, a photocurable film of a photosensitive resin composition containing a carboxyl-containing photosensitive resin and a photopolymerization initiator is used. In addition, in order to prevent the photocurable film from turning yellow, prevent halo during photocuring reaction, stabilize the shape of the through-hole opening, etc., an antioxidant is sometimes added to the photosensitive resin composition.

[0003] Therefore, in order to prevent the photocured film from yellowing and prevent haloing during photocuring reaction, for example, a photosensitive resin composition containing an antioxidant has been proposed (Patent Document 1), which contains (A) a carboxyl group-containing photosensitive resin, (B) a phenolic compound, (C) an organic sulfur compound, (D) a photopolymerization initiator, (E) a diluent, (F) an epoxy compound, and (G) a colorant. In Patent Document 1, (B) a phenolic compound and (C) an organic sulfur compound are added as antioxidants to prevent the photocured film from yellowing and prevent haloing during photocuring reaction.

[0004] On the other hand, due to the miniaturization of electronic components mounted on printed circuit boards and the high-density mounting of electronic components, high resolution is sometimes required for solder resist films. In order to improve the resolution of solder resist films, photosensitive resin compositions that achieve high sensitivity to ultraviolet rays are sometimes required. In order to achieve high sensitivity of the photosensitive resin composition, oxime ester photopolymerization initiators are sometimes used as photopolymerization initiators.

[0005] However, when an oxime ester photopolymerization initiator is used, the sensitivity of the photosensitive resin composition becomes too high, and even if an antioxidant such as a phenolic compound or an organic sulfur compound is added, halation cannot be sufficiently suppressed, resulting in, for example, small-diameter through-hole openings not being developed. Therefore, there is room for improvement in alkali developability.

[0006] In addition, when the photosensitive resin composition is photocured under the condition where the oxygen barrier effect is small (for example, a state where a resin film such as PET is laminated on a coating of the photosensitive resin composition), if an oxime ester photopolymerization initiator is used, ultraviolet rays will reach an undesirable coating area, thereby excessively performing the photocuring reaction of the coating, and sometimes causing defects such as scum in the photocured film. If defects such as scum are generated in the photocured film, for example, for the photocured film of the photosensitive resin composition formed on the conductor, when a plating treatment such as gold plating is performed, unevenness is generated in the gold-plated film, and sometimes the coating is not attached and fixed. Therefore, for the conventional photosensitive resin composition that is combined with an antioxidant of a phenolic compound or an organic sulfur compound, there is room for improvement in plating properties such as gold plating.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: JP2011-70108A Summary of the invention

[0010] Technical problem to be solved by the invention

[0011] In view of the above circumstances, an object of the present invention is to provide a photosensitive resin composition capable of forming a photocured film having excellent alkali developability, gold plating property and other plating properties without impairing high sensitivity to ultraviolet rays.

[0012] Technical solutions to the problem

[0013] The gist of the present invention is as follows.

[0014] [1] A photosensitive resin composition comprising (A) a carboxyl group-containing photosensitive resin, (B) an antioxidant, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound, wherein the (B) antioxidant comprises at least one compound selected from (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur.

[0015] [2] The photosensitive resin composition according to [1], wherein the (B) antioxidant contains the (B1) compound having a phenolic hydroxyl group and phosphorus.

[0016] [3] The photosensitive resin composition according to [1] or [2], comprising 0.40 parts by mass or more and 12.0 parts by mass or less of the antioxidant (B) based on 100 parts by mass of the carboxyl group-containing photosensitive resin (A).

[0017] [4] The photosensitive resin composition according to [2], comprising 2.0 parts by mass or more and 6.0 parts by mass or less of the (B1) compound having a phenolic hydroxyl group and phosphorus, based on 100 parts by mass of the (A) carboxyl group-containing photosensitive resin.

[0018] [5] The photosensitive resin composition according to any one of [1] to [4], wherein the (B) antioxidant contains the (B2) compound having a phenolic hydroxyl group and sulfur, and the (B2) compound having a phenolic hydroxyl group and sulfur is contained in an amount of 0.50 parts by mass to 1.5 parts by mass based on 100 parts by mass of the (A) carboxyl group-containing photosensitive resin.

[0019] [6] The photosensitive resin composition according to any one of [1] to [5], wherein the (B1) compound having a phenolic hydroxyl group and phosphorus is a compound of the following formula (1).

[0020]

[0021] [7] The photosensitive resin composition according to any one of [1] to [6], wherein the (B2) compound having a phenolic hydroxyl group and sulfur is a compound of the following formula (2).

[0022]

[0023] [8] The photosensitive resin composition according to any one of [1] to [7], wherein the (C) photopolymerization initiator contains an oxime ester-based photopolymerization initiator.

[0024] [9] A photocured product, which is a photocured product of the photosensitive resin composition according to any one of [1] to [8].

[0025]

[10] A dry film comprising the photosensitive resin composition according to any one of [1] to [8].

[0026]

[11] A printed wiring board comprising a photocured product of the photosensitive resin composition according to any one of [1] to [8].

[0027] Effects of the Invention

[0028] According to the technical solution of the present invention, the antioxidant (B) contains at least one compound selected from the group consisting of (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur, so that a photosensitive resin composition can be obtained that can form a photocured film that does not impair the high sensitivity to ultraviolet rays and has excellent plating properties such as gold plating properties. In addition, according to the technical solution of the present invention, the antioxidant (B) contains at least one compound selected from the group consisting of (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur, so that excellent alkali developability can be obtained, so that alkali development of non-exposed parts of the coating film of the photosensitive resin composition can be reliably achieved, and the coating film can be reliably removed by alkali development even in a small-diameter through-hole opening.

[0029] According to the technical aspect of the present invention, the (B) antioxidant contains the (B1) compound having a phenolic hydroxyl group and phosphorus, so that the alkali developability is further improved, and the alkali development of the non-exposed portion of the coating film of the photosensitive resin composition can be achieved more reliably.

[0030] According to the technical solution of the present invention, 0.40 parts by mass or more and 12.0 parts by mass or less of (B) antioxidant is contained relative to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin, thereby reliably improving the sensitivity to ultraviolet rays and further improving the plating properties such as alkali developability and gold plating properties.

[0031] According to the invention, by containing 2.0 to 6.0 parts by mass of the compound (B1) having a phenolic hydroxyl group and phosphorus per 100 parts by mass of the carboxyl group-containing photosensitive resin (A), the sensitivity and plating properties such as gold plating properties are improved in a balanced manner.

[0032] According to the technical solution of the present invention, the (B) antioxidant contains (B2) a compound having a phenolic hydroxyl group and sulfur, and the (B2) compound having a phenolic hydroxyl group and sulfur is contained in an amount of 0.50 parts by mass to 1.5 parts by mass relative to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin, thereby improving the plating properties such as alkali developability and gold plating properties in a balanced manner. DETAILED DESCRIPTION

[0033] Next, the photosensitive resin composition of the present invention is described. The photosensitive resin composition of the present invention is a photosensitive resin composition containing (A) a carboxyl group-containing photosensitive resin, (B) an antioxidant, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound, wherein the (B) antioxidant contains at least one compound selected from the group consisting of (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur.

[0034] (A) Carboxyl-containing photosensitive resin

[0035] The chemical structure of the carboxyl-containing photosensitive resin as component (A) is not particularly limited, and for example, a resin having one or more photosensitive unsaturated double bonds and free carboxyl groups can be cited. As the carboxyl-containing photosensitive resin, for example, polyacid-modified free radical polymerizable unsaturated monocarboxylic acid epoxy resins such as polyacid-modified epoxy (meth) acrylates can be cited as follows: free radical polymerizable unsaturated monocarboxylic acid such as acrylic acid and methacrylic acid (hereinafter sometimes referred to as "(meth) acrylic acid") is reacted with at least a part of the epoxy groups of a multifunctional epoxy resin having two or more epoxy groups in one molecule to obtain free radical polymerizable unsaturated monocarboxylic acid epoxy resins such as epoxy (meth) acrylates, and polyacids and / or polyacid anhydrides are reacted with the generated hydroxyl groups to obtain free radical polymerizable unsaturated monocarboxylic acid epoxy resins.

[0036] The multifunctional epoxy resin has no particular limitation on chemical structure as long as it is an epoxy resin with two or more functions. In addition, the epoxy equivalent of the multifunctional epoxy resin is not particularly limited. For example, the upper limit of the epoxy equivalent is preferably 3000 g / eq, more preferably 2000 g / eq, and particularly preferably 1500 g / eq. On the other hand, the lower limit of the epoxy equivalent is preferably 100 g / eq, and particularly preferably 200 g / eq.

[0037] As the resin type of the multifunctional epoxy resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, rubber modified epoxy resin such as silicone modified epoxy resin, ε-caprolactone modified epoxy resin, o-cresol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, cyclic aliphatic multifunctional epoxy resin, glycidyl ester type multifunctional epoxy resin, glycidyl amine type multifunctional epoxy resin, heterocyclic multifunctional epoxy resin, bisphenol modified novolac type epoxy resin, multifunctional modified novolac type epoxy resin, etc. In addition, products further introduced with halogen atoms such as Br and Cl in the above-mentioned epoxy resins can also be used. The above-mentioned multifunctional epoxy resins may be used alone or in combination of two or more.

[0038] The free radical polymerizable unsaturated monocarboxylic acid is not particularly limited, and examples thereof include (meth) acrylic acid, crotonic acid, methyl crotonic acid, angelic acid, cinnamic acid, etc. Among them, (meth) acrylic acid is preferred from the perspective of availability and handling. The free radical polymerizable unsaturated monocarboxylic acid may be used alone, or two or more free radical polymerizable unsaturated monocarboxylic acids may be used simultaneously.

[0039] The method for reacting the polyfunctional epoxy resin and the radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and examples thereof include a method of dissolving the polyfunctional epoxy resin and the radically polymerizable unsaturated monocarboxylic acid in a non-reactive diluent such as an organic solvent and heating the mixture.

[0040] The polyacid and / or polyacid anhydride react with the hydroxyl group generated by the reaction of the multifunctional epoxy resin and the free radical polymerizable unsaturated monocarboxylic acid to introduce the free carboxyl group into the free radical polymerizable unsaturated monocarboxylic acid epoxy resin. The chemical structure of the polyacid and polyacid anhydride is not particularly limited, and any saturated or unsaturated structure can be used. As polyacid, for example, tetrahydrophthalic acids such as succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, hexahydrophthalic acids such as hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, tetrahydrophthalic acids such as methylenetetrahydrophthalic acid, methylmethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid and diglycolic acid etc. can be enumerated. As polyacid anhydride, the anhydride of the above-mentioned various polyacids can be enumerated. The above-mentioned compound can be used alone, and two or more of the above-mentioned compounds can also be used simultaneously.

[0041] The method for reacting the radically polymerizable unsaturated monocarboxylic acid-containing epoxy resin and the polybasic acid and / or polybasic acid anhydride is not particularly limited. Examples thereof include a method of dissolving the radically polymerizable unsaturated monocarboxylic acid-containing epoxy resin and the polybasic acid and / or polybasic acid anhydride in a non-reactive diluent such as an organic solvent and heating the mixture.

[0042] The above-mentioned polyacid-modified unsaturated monocarboxylic acid epoxy resin can be used as a carboxyl-containing photosensitive resin. In addition, a polyacid-modified free radical polymerizable unsaturated monocarboxylic acid epoxy resin further added with a free radical polymerizable unsaturated group, which is obtained by addition reaction of a compound having more than one free radical polymerizable unsaturated group and an epoxy group with a part of the carboxyl group of the polyacid-modified unsaturated monocarboxylic acid epoxy resin obtained in the above manner, can be used as a carboxyl-containing photosensitive resin. The polyacid-modified free radical polymerizable unsaturated monocarboxylic acid epoxy resin further added with a free radical polymerizable unsaturated group has a chemical structure in which a free radical polymerizable unsaturated group is further introduced into the side chain of the polyacid-modified unsaturated monocarboxylic acid epoxy resin, and therefore, is a carboxyl-containing photosensitive resin with further improved photosensitivity compared with the polyacid-modified unsaturated monocarboxylic acid epoxy resin.

[0043] Examples of compounds having one or more free radical polymerizable unsaturated groups and epoxy groups include glycidyl compounds. Examples of glycidyl compounds include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether, pentaerythritol trimethacrylate monoglycidyl ether, and the like. Glycidyl compounds may have one glycidyl group or multiple glycidyl groups in one molecule. In addition, compounds having one or more free radical polymerizable unsaturated groups and epoxy groups may be used alone or in combination of two or more.

[0044] The method for reacting the polyacid-modified unsaturated monocarboxylic acid epoxy resin with a compound having one or more free radical polymerizable unsaturated groups and epoxy groups, such as a glycidyl compound, is not particularly limited. For example, there can be cited a method in which the polyacid-modified unsaturated monocarboxylic acid epoxy resin and a compound having one or more free radical polymerizable unsaturated groups and epoxy groups are dissolved in a non-reactive diluent such as an organic solvent and heated.

[0045] The acid value of the carboxyl group-containing photosensitive resin is not particularly limited. For example, from the perspective of developing with an alkali, the lower limit is preferably 30 mgKOH / g, and particularly preferably 40 mgKOH / g. On the other hand, for example, from the perspective of preventing the exposed portion from being dissolved by an alkali developer, the upper limit of the acid value of the carboxyl group-containing photosensitive resin is preferably 200 mgKOH / g, and from the perspective of reliably preventing the moisture resistance and insulation reliability of the photocured product from being reduced, it is particularly preferably 150 mgKOH / g.

[0046] The mass average molecular weight of carboxyl-containing photosensitive resin is not particularly limited, for example, from the toughness of photocurable material and dryness to touch, its lower limit is preferably 6000, more preferably 7000, and particularly preferably 8000. On the other hand, for example, from the aspect of adopting alkali development, the upper limit of the mass average molecular weight of carboxyl-containing photosensitive resin is preferably 200000, more preferably 100000, and particularly preferably 50000. In addition, " mass average molecular weight " refers to the mass average molecular weight calculated by utilizing gel permeation chromatography (GPC) to measure at normal temperatures and converting by polystyrene.

[0047] About the carboxyl group-containing photosensitive resin, it is possible to utilize the above-mentioned various components to prepare through the above-mentioned reaction process, or commercially available carboxyl group-containing photosensitive resins can be used. As commercially available carboxyl group-containing photosensitive resins, for example, "KAYARAD ZAR-2000", "KAYARAD ZFR-1122", "KAYARAD FLX-2089", "KAYARAD ZCR-1569H" (manufactured by Nippon Kayaku Co., Ltd.), "CYCLOMER P (ACA) Z-250" (Daicel Allnex Ltd.), "SP-4621" (Showa Denko K.K.), etc. can be cited. In addition, the above-mentioned carboxyl group-containing photosensitive resin can be used alone, or two or more of the above-mentioned carboxyl group-containing photosensitive resins can be used simultaneously.

[0048] (B) Antioxidants

[0049] As the antioxidant of the component (B), at least one compound selected from the group consisting of (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur is used. By using at least one compound selected from the group consisting of (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur as the antioxidant of the component (B), a photosensitive resin composition can be obtained that can form a photocured film that has high sensitivity to active energy rays such as ultraviolet rays and excellent plating properties such as gold plating properties without impairing the photosensitive resin composition. In addition, it is possible to sufficiently prevent halation and obtain excellent alkali developability. Therefore, the non-exposed portion of the coating of the photosensitive resin composition can be reliably removed by alkali development. For example, the coating can be reliably removed by alkali development even in a small-diameter through-hole opening or a fine pad portion.

[0050] Examples of the compound having a phenolic hydroxyl group and phosphorus as the component (B1) include a compound having a phenolic hydroxyl group and a structure consisting of P(OR 1 )(OR 2 )(OR 3 )(R 1 , R 2 , R 3 A compound having a phosphite structure represented by an organic group). The skeleton includes a phenolic hydroxyl group and a P(OR 1 )(OR 2 )(OR 3 ) can be represented by a phosphite structure, for example, a compound represented by the following formula (1).

[0051]

[0052] In addition, the compound may be a compound having a phenolic hydroxyl group and phosphorus in which the butyl group in the above formula (1) is replaced by hydrogen, an alkyl group having 1 to 3 carbon atoms, or an alkyl group having 5 to 10 carbon atoms, or a compound having a phenolic hydroxyl group and phosphorus in which the methyl group in the above formula (1) is replaced by hydrogen, an alkyl group having 2 to 10 carbon atoms. Examples of the compound represented by the above formula (1) include "Sumilizer GP" (Sumitomo Chemical Co., Ltd.).

[0053] Examples of the compound having a phenolic hydroxyl group and sulfur as the component (B2) include phenol substituted with -R 4 -SR 5 (Where R 4 represents a hydrocarbon having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and R 5 represents a hydrocarbon having 5 to 20 carbon atoms, preferably 10 to 15 carbon atoms. ) substituted compound. Substituent -R 4 -SR 5 The number is at least 1, preferably 2.

[0054] As phenol is -R 4 -SR 5 Examples of the substituted compound include compounds represented by the following formula (2).

[0055]

[0056] Examples of the compound represented by the above formula (2) include "Irganox 1726" (BASF Corporation).

[0057] The photosensitive resin composition of the present invention may use a compound having a phenolic hydroxyl group and phosphorus and a compound having a phenolic hydroxyl group and sulfur at the same time, or may use any one of the compound having a phenolic hydroxyl group and phosphorus and the compound having a phenolic hydroxyl group and sulfur. Among them, the compound having a phenolic hydroxyl group and phosphorus is preferred from the viewpoint of further improving the alkali developability and more reliably removing the non-exposed portion of the coating film of the photosensitive resin composition by alkali development.

[0058] The amount of at least one compound selected from the group consisting of a compound having a phenolic hydroxyl group and phosphorus and a compound having a phenolic hydroxyl group and sulfur is not particularly limited. From the perspective of further improving the plating properties such as gold plating properties, the lower limit is preferably 0.40 parts by mass, more preferably 0.50 parts by mass, more preferably 1.0 parts by mass, and particularly preferably 2.0 parts by mass relative to 100 parts by mass of the carboxyl-containing photosensitive resin (solid content, the same below). On the other hand, from the perspective of reliably improving the sensitivity to ultraviolet rays and obtaining excellent alkali developability, the upper limit of the amount of at least one compound selected from the group consisting of a compound having a phenolic hydroxyl group and phosphorus and a compound having a phenolic hydroxyl group and sulfur is preferably 12.0 parts by mass, more preferably 10.0 parts by mass, and particularly preferably 5.0 parts by mass relative to 100 parts by mass of the carboxyl-containing photosensitive resin.

[0059] In addition, when a compound having a phenolic hydroxyl group and phosphorus is added but a compound having a phenolic hydroxyl group and sulfur is not added, the lower limit of the amount of the compound having a phenolic hydroxyl group and phosphorus is preferably 1.0 parts by mass, more preferably 1.5 parts by mass, and particularly preferably 2.0 parts by mass relative to 100 parts by mass of the photosensitive resin containing a carboxyl group, from the perspective of further improving plating properties such as gold plating properties. On the other hand, when a compound having a phenolic hydroxyl group and phosphorus is added but a compound having a phenolic hydroxyl group and sulfur is not added, the upper limit of the amount of the compound having a phenolic hydroxyl group and phosphorus is preferably 10.0 parts by mass, more preferably 7.5 parts by mass, further preferably 6.0 parts by mass, and particularly preferably 5.0 parts by mass relative to 100 parts by mass of the photosensitive resin containing a carboxyl group, from the perspective of further improving sensitivity.

[0060] In addition, when a compound having a phenolic hydroxyl group and sulfur is added but a compound having a phenolic hydroxyl group and phosphorus is not added, the lower limit of the compound having a phenolic hydroxyl group and sulfur is preferably 0.50 parts by mass, and particularly preferably 0.75 parts by mass, relative to 100 parts by mass of the photosensitive resin containing a carboxyl group, from the perspective of further improving plating properties such as gold plating properties. On the other hand, when a compound having a phenolic hydroxyl group and sulfur is added but a compound having a phenolic hydroxyl group and phosphorus is not added, the upper limit of the compound having a phenolic hydroxyl group and sulfur is preferably 2.5 parts by mass, more preferably 2.0 parts by mass, and particularly preferably 1.5 parts by mass, relative to 100 parts by mass of the photosensitive resin containing a carboxyl group, from the perspective of further improving alkali developability.

[0061] In addition, as the (B) antioxidant, if necessary, the (B1) compound having a phenolic hydroxyl group and phosphorus and / or the (B2) compound having a phenolic hydroxyl group and sulfur, and antioxidants other than the (B1) component and the (B2) component (hereinafter, sometimes referred to as "other antioxidants"). Examples of other antioxidants used simultaneously include phenolic antioxidants that do not contain phosphorus and sulfur (hereinafter, sometimes referred to as "phenolic antioxidants"), phosphorus antioxidants that do not have a phenolic hydroxyl group (hereinafter, sometimes referred to as "phosphorus antioxidants"), and sulfur antioxidants that do not have a phenolic hydroxyl group (hereinafter, sometimes referred to as "sulfur antioxidants"), etc.

[0062] Examples of the phenolic antioxidant include 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis{2-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis{2-[3-(3-isobutyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1′-dimethyl Hindered phenol antioxidants include 2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis{2-[3-(4-hydroxy-5-methylphenyl)propionyloxy]1,1′-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis{2-[3-(3-tert-butyl-5-ethyl-4-hydroxyphenyl)propionyloxy]1,1′-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, and stearyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. Examples of commercially available hindered phenol antioxidants include “Irganox 1010” (from BASF).

[0063] Examples of the phosphorus antioxidant include tris(2,4-di-tert-butylphenyl)phosphite commercially available as "Irgafos 168" (BASF).

[0064] Examples of the sulfur-based antioxidant include organic sulfur compounds represented by the following general formula (I).

[0065] (R 6 -S-CH2CH2COOCH2)4C····(I)

[0066] (In formula (I), R 6 represents an alkyl group having 10 to 20 carbon atoms, 4 R 6 can be the same or different. ), as R 6That is, the alkyl group has 10 to 20 carbon atoms, and examples thereof include lauryl, myristyl, palmityl, stearyl, etc. Examples of commercially available sulfur-based antioxidants include "Sumilizer TP-D" (Sumitomo Chemical Co., Ltd.).

[0067] The amount of other antioxidants is not particularly limited, but from the perspective of reliably contributing to the suppression of halo, the lower limit is preferably 0.05 parts by mass, particularly preferably 0.10 parts by mass, relative to 100 parts by mass of the carboxyl group-containing photosensitive resin. On the other hand, from the perspective of reliably maintaining high sensitivity, the upper limit of the amount of other antioxidants is preferably 2.0 parts by mass, particularly preferably 1.0 parts by mass, relative to 100 parts by mass of the carboxyl group-containing photosensitive resin.

[0068] (C) Photopolymerization initiator

[0069] The photopolymerization initiator as the component (C) is not particularly limited, and any photopolymerization initiator can be used. Examples of the photopolymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyl oxime)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-, 1-(O-acetyl oxime), 2-(acetoxyiminomethyl)thioxanthen-9-one, 1,8-octanedione, 1,8-bis[9-ethyl-6-nitro-9H-carbazole-3- Oxime ester photopolymerization initiators include oxime esters such as ((1-methoxypropane-2-yl)oxy)-2-methylphenyl)methanone O-acetoxime, (((1-methoxypropane-2-yl)oxy)-2-methylphenyl)methanone)-1,8-bis(O-acetoxime), 1,8-octanedione, 1,8-bis[9-(2-ethylhexyl)-6-nitro-9H-carbazole-3-yl]-, 1,8-bis(O-acetoxime), (Z)-(9-ethyl-6-nitro-9H-carbazole-3-yl)(4-((1-methoxypropane-2-yl)oxy)-2-methylphenyl)methanone O-acetoxime. The above compounds may be used alone or in combination of two or more. The oxime ester photopolymerization initiators can impart high sensitivity to active energy rays such as ultraviolet rays to the photosensitive resin composition.

[0070] In the present invention, even when an oxime ester photopolymerization initiator is added, since the (B) antioxidant contains at least one compound selected from the group consisting of (B1) a compound having a phenolic hydroxyl group and phosphorus and (B2) a compound having a phenolic hydroxyl group and sulfur, it is possible to prevent haloing during the photocuring reaction, and form a photocured film having excellent alkali developability, gold plating property and other plating properties.

[0071] In addition, photopolymerization initiators other than oxime ester photopolymerization initiators can be used, for example, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1-benzyl-1-(dimethylamino)propyl-4-morpholinophenyl ketone, 2-methyl-4′-(methylthio)-2-morpholinophenyl propiophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl propiophenone)-1-(4-methylthio)-2-morpholinophenyl propiophenone, 2-benzyl-2-dimethylamino ... 1-Hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4′-bis(diethylamino)benzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzil dimethyl ketal, acetophenone dimethyl ketal, ethyl p-dimethylaminobenzoate, etc. The above compounds may be used alone or in combination of two or more.

[0072] The content of the photopolymerization initiator is not particularly limited, but is preferably 0.10 to 10 parts by mass, and particularly preferably 0.50 to 5.0 parts by mass, based on 100 parts by mass of the carboxyl group-containing photosensitive resin.

[0073] (D) Reactive diluent

[0074] The reactive diluent as component (D) is, for example, a photopolymerizable monomer, and is a compound having at least one, preferably two or more polymerizable double bonds per molecule. The reactive diluent allows the photosensitive resin composition to be fully photocured, and helps improve the acid resistance, heat resistance, alkali resistance, etc. of the photocured product.

[0075] As the reactive diluent, for example, monofunctional (meth)acrylate monomers and (meth)acrylate monomers having two or more functions can be cited. As the monofunctional (meth)acrylate monomer, for example, 2-hydroxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, diethylene glycol mono(meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and caprolactone-modified (meth)acrylate can be cited. In addition, as the (meth)acrylate monomers having two or more functions, for example, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, adipate neopentyl glycol di(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, dicyclopentyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, and allyl di(meth)acrylate can be cited. Cyclohexyl ester, isocyanurate di(meth)acrylate, trimethylolpropane tri(meth)acrylate, di(trimethylolpropane) tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tri(acryloyloxyethyl)isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, urethane (meth)acrylate, etc. These compounds may be used alone or in combination of two or more thereof.

[0076] The amount of the reactive diluent to be added is not particularly limited, but is preferably 5.0 to 100 parts by mass, and particularly preferably 10 to 30 parts by mass, based on 100 parts by mass of the carboxyl group-containing photosensitive resin.

[0077] (E) Epoxy compounds

[0078] The epoxy compound as component (E) is used to obtain a photocured film with sufficient mechanical strength by increasing the crosslinking density of the photocured product of the photosensitive resin composition. As the epoxy compound, for example, epoxy resin can be cited. As the epoxy resin, for example, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, bisphenol A type epoxy resin, tetramethyl bisphenol F type epoxy resin and other bisphenol F type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, dicyclopentadiene type epoxy resins, adamantane type epoxy resins can be cited. Among them, from the perspective of further improving the pot life, preferably bisphenol A type epoxy resin, biphenyl type epoxy resin, tetramethyl bisphenol F type epoxy resin, particularly preferably biphenyl type epoxy resin, tetramethyl bisphenol F type epoxy resin. The above compounds can be used alone, and two or more of the above compounds can also be used simultaneously.

[0079] The amount of the epoxy compound is not particularly limited, but is preferably 5.0 to 100 parts by mass, particularly preferably 10 to 50 parts by mass, based on 100 parts by mass of the carboxyl group-containing photosensitive resin, in order to reliably obtain a photocured product having sufficient mechanical strength.

[0080] In addition to the above components (A) to (E), the photosensitive resin composition of the present invention may contain other components such as extender pigments, flame retardants, curing accelerators, additives, colorants, non-reactive diluents, etc. as needed.

[0081] Examples of body pigments include talc, barium sulfate, hydrophobic silica, aluminum oxide, aluminum hydroxide, mica, and the like. Flame retardants are used to impart flame retardancy to the photocured product of the photosensitive resin composition of the present invention, and examples thereof include phosphorus-based flame retardants. Examples of phosphorus-based flame retardants include tris(chloroethyl) phosphate, tris(2,3-dichloropropyl) phosphate, tris(2-chloropropyl) phosphate, tris(2,3-bromopropyl) phosphate, tris(bromochloropropyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris(tribromophenyl) phosphate, tris(dibromophenyl) phosphate, tris(tribromoneopentyl) phosphate, and halogen-containing phosphates such as trimethyl phosphate, triethyl phosphate, and tributyl phosphate. Ester, trioctyl phosphate, tributoxyethyl phosphate and other non-halogen aliphatic phosphates; triphenyl phosphate, cresyl diphenyl phosphate, di(cresyl)phenyl phosphate, tricresyl phosphate, tricresyl phosphate, di(xylyl) phosphate, ditolyl diphenyl phosphate, tri(isopropyl phenyl) phosphate, isopropyl phenyl diphenyl phosphate, diisopropyl phenyl phenyl phosphate, tri(trimethylphenyl) phosphate, tri(tert-butylphenyl) phosphate, hydroxyphenyl diphenyl phosphate Ester, octyl diphenyl phosphate and other non-halogen aromatic phosphates; tris(diethylphosphinate)aluminum, tris(methylethylphosphinate)aluminum, tris(diphenylphosphinate)aluminum, bis(diethylphosphinate)zinc, bis(methylethylphosphinate)zinc, bis(diphenylphosphinate)zinc, bis(diethylphosphinate)titanium, tetrakis(diethylphosphinate)titanium, bis(methylethylphosphinate)titanium, tetrakis(methylethylphosphinate)titanium, bis(diphenylphosphinate)titanium, tetrakis(diethylphosphinate)titanium The invention also includes metal salts of phosphinic acid such as titanium phosphinate (phenylphosphinic acid), 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (hereinafter referred to as HCA), HCA-acrylate addition reaction products, HCA-epoxy addition reaction products, HCA-hydroquinone addition reaction products and other HCA-modified compounds, diphenylvinylphosphine oxide, triphenylphosphine oxide, trialkylphosphine oxide, tris (hydroxyalkyl) phosphine oxide and other phosphine oxide compounds, etc. Among them, organic phosphate flame retardants are preferred.

[0082] As curing accelerators, there can be mentioned mercaptobenzoxazole and its derivatives, dicyandiamide (DICY) and its derivatives, melamine and its derivatives, boron trifluoride-amine complexes, organic acid hydrazides, diaminomaleonitrile (DAMN) and its derivatives, guanamine and its derivatives, amine imide (AI) and polyamines, etc. As additives, there can be mentioned defoaming agents such as silicones, hydrocarbons and acrylic acids, thixotropic agents such as polycarboxylic acid amides, etc.

[0083] The colorant is not particularly limited to pigments, dyes, etc., and colorants of any color such as white colorants, blue colorants, green colorants, yellow colorants, purple colorants, black colorants, and orange colorants may be used. Examples of the colorant include titanium oxide (rutile type, anatase type) as a white colorant, carbon black, acetylene black and other inorganic colorants as a black colorant, phthalocyanine green as a green colorant, phthalocyanines such as phthalocyanine blue and Lionol blue as a blue colorant, anthraquinones, and organic colorants such as diketopyrrolopyrroles such as Chromophthal orange as an orange colorant.

[0084] The non-reactive diluent is used to adjust the coating and drying properties of the photosensitive resin composition. Examples of the non-reactive diluent include organic solvents. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, ethanol, propanol, and cyclohexanol, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, petroleum solvents such as petroleum ether and naphtha, cellosolves such as cellosolves and butyl cellosolves, carbitols such as carbitols and butyl carbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, ethylene glycol acetate, ethyl diglycol acetate, and other esters. The above compounds may be used alone or in combination.

[0085] The method for producing the photosensitive resin composition of the present invention is not limited to a specific method, and for example, the above-mentioned components can be mixed in a predetermined ratio, and then kneaded or mixed at room temperature (normal temperature) using a kneading unit such as a triple roll, a ball mill, or a sand mill, or a stirring unit such as a super mixer or a planetary mixer. In addition, pre-kneading or pre-mixing can be performed at room temperature (normal temperature) as needed before the kneading or mixing.

[0086] Next, an example of a method of using the photosensitive resin composition of the present invention will be described. First, a method of forming a solder resist film using a dry film coated with the photosensitive resin composition of the present invention on a printed wiring board having a circuit pattern formed by etching a conductor foil will be described.

[0087] The dry film is a laminated structure having a supporting film (e.g., a thermoplastic film such as polyethylene terephthalate film and polyester film), a solder resist layer applied to the supporting film, and a cover film (e.g., polyethylene film and polypropylene film) for protecting the solder resist layer. After the photosensitive resin composition of the present invention is applied to the supporting film by a known method such as a roller coating method and a rod coating method to form a coating film, the coating film is dried to form a solder resist layer on the supporting film. Then, the cover film is laminated on the formed solder resist layer, thereby making it possible to produce a dry film having a coating film of the photosensitive resin composition of the present invention.

[0088] While peeling off the cover film of the dry film, the solder resist layer and the printed circuit board are bonded to form a solder resist film on the printed circuit board. Then, as needed, in order to volatilize the non-reactive diluent (organic solvent) in the photosensitive resin composition, pre-drying is performed at a temperature of about 70°C to 120°C for about 1 minute to 20 minutes, so that the non-reactive diluent (organic solvent) is volatilized from the photosensitive resin composition, so that the surface of the solder resist film is formed into a non-sticky state. A negative film (negative film) with a light-transmitting pattern is closely attached to the formed solder resist film except for the pads of the circuit pattern, and ultraviolet rays (for example, a wavelength of 300nm to 400nm) are irradiated from the top of the negative film. Then, the non-exposed area corresponding to the pad is removed using a dilute alkali aqueous solution to develop the solder resist film. For the development method, a spray method, a shower method, etc. can be used. As the dilute alkali aqueous solution used, for example, a 0.5% to 5% sodium carbonate aqueous solution can be cited. After development, post-curing (thermal curing treatment) is performed at 130° C. to 170° C. for 20 minutes to 80 minutes using a hot air circulation dryer or the like, whereby a solder resist film having a target pattern can be formed on the printed wiring board.

[0089] Next, as an example of the use of the photosensitive resin composition of the present invention, a method for applying the photosensitive resin composition to a printed circuit board to form an insulating protective film (e.g., a solder resist film) is described. The photosensitive resin composition of the present invention obtained in the above manner is applied to a printed circuit board having a circuit pattern to form a coating film with a desired thickness by other known coating methods such as screen printing, spraying, rod coating, application, scraper coating, scraper coating, roller coating, and gravure coating. Next, as needed, in order to volatilize the non-reactive diluent, pre-drying is performed at a temperature of about 60°C to 100°C for 15 minutes to 60 minutes, thereby forming a non-sticky coating film. Next, a negative film having a light-transmitting pattern other than the pad of the circuit pattern is closely attached to the coating film, and ultraviolet rays (e.g., a wavelength of 300nm to 400nm) are irradiated from above the negative film to photocure the coating film. In addition, the non-exposed area corresponding to the pad is removed using a dilute alkali aqueous solution to develop the coating film. For the developing method, a spray method, a shower method, etc. are used. As the diluted alkali aqueous solution used, for example, a 0.5 mass % to 5 mass % sodium carbonate aqueous solution can be cited. Next, a hot air circulation dryer is used to perform post-curing (thermocuring treatment) at 130° C. to 170° C. for 20 minutes to 80 minutes, thereby forming a solder resist film with a target pattern on a printed circuit board.

[0090] Example

[0091] Next, embodiments of the present invention will be described, but the present invention is not limited to the above-described embodiments unless exceeding the scope of the invention.

[0092] Examples 1 to 9, Comparative Examples 1 to 3

[0093] The components shown in Table 1 below were mixed in the mixing ratio shown in Table 1 below, and mixed and dispersed at room temperature (25° C.) using a triple roll to prepare the photosensitive resin compositions used in Examples 1 to 9 and Comparative Examples 1 to 3. Unless otherwise specified, the mixing amount of each component shown in Table 1 below is expressed in parts by mass. In addition, the blank part of the mixing amount in Table 1 below indicates that the component is not mixed.

[0094] Hereinafter, each component in the following Table 1 will be described in detail.

[0095] (A) Carboxyl-containing photosensitive resin

[0096] ·KAYARAD ZAR-2000: solid content (resin content) 65% by mass, Nippon Kayaku Co., Ltd.

[0097] KAYARAD ZAR-2000 is a polyacid-modified epoxy acrylate resin obtained by reacting acrylic acid with at least a part of epoxy groups of an epoxy resin (bisphenol A type epoxy resin) to obtain epoxy acrylate, and reacting a polyacid with a hydroxyl group generated by the epoxy acrylate.

[0098] (B) Antioxidants

[0099] ·SumilizerGP: compound of formula (1), Sumitomo Chemical Co., Ltd.

[0100] Irganox1726: Compound of formula (2), BASF

[0101] Irganox 1010: phenolic antioxidant, BASF

[0102] Irgafos 168: Phosphorus antioxidant, BASF

[0103] (C) Photopolymerization initiator

[0104] ·NCI-831: Oxime ester photopolymerization initiator, ADEKA Corporation

[0105] OXE-02: Oxime ester photopolymerization initiator, BASF

[0106] (D) Reactive diluent

[0107] ·EBERCRYL8405: Daicel Cytec Co., Ltd.

[0108] (E) Epoxy compounds

[0109] ·EPICRON 850-S: DIC Co., Ltd.

[0110] Extender Pigment

[0111] ·Hydilite H42M: Showa Denko Co., Ltd.

[0112] Flame retardants

[0113] Exolit OP-935: Clariant Japan

[0114] Curing accelerator

[0115] Melamine: Nissan Chemical Industries, Ltd.

[0116] ·DICY-7: Mitsubishi Chemical Corporation

[0117] additive

[0118] ·X-50-1095C: Defoaming agent, Shin-Etsu Chemical Co., Ltd.

[0119] Colorants

[0120] Chromophthal DPP Orange TR: Ciba Specialty Chemicals

[0121] Non-reactive diluent

[0122] ·EDGAC: Sanyo Chemicals Co., Ltd.

[0123] Test body production process

[0124] A test piece was prepared using the prepared photosensitive resin composition in the following manner.

[0125] Substrate: Glass epoxy substrate, "FR4", copper foil thickness 25μm

[0126] Substrate surface treatment: 5 mass% sulfuric acid treatment

[0127] Coating: Screen printing

[0128] Pre-drying: using BOX oven, 80℃, 20 minutes

[0129] Exposure: Direct-drawing exposure machine (Nuvogo 800, Orbotech) at 100 mJ / cm 2 ~300mJ / cm 2 Exposure processing is performed under the exposure conditions

[0130] Alkali development: 1 mass% Na2CO3 aqueous solution, liquid temperature 30°C, spray pressure 0.2MPa, development time 60 seconds

[0131] Post-curing (heating treatment for main curing): 150°C, 60 minutes

[0132] The thickness of the photocured film of the test piece obtained in the above manner was 20 μm to 23 μm.

[0133] Evaluation Project

[0134] (1) Sensitivity

[0135] In the test piece preparation process, a step exposure meter (Kodak, 21 steps) for sensitivity measurement was set on the coated substrate after pre-drying at 80°C for 20 minutes, and the photosensitive substrate was subjected to 100 mJ / cm 2The exposed sample is set as a test piece. After exposure, the unremoved portion of the exposed portion after development with a 1 mass % Na2CO3 aqueous solution at a spray pressure of 0.2 MPa and a development time of 60 seconds is indicated by a number (grade). The larger the grade, the better the photosensitivity.

[0136] (2) Alkali developability

[0137] In the test body preparation process, after applying the photosensitive resin composition by spraying instead of screen printing, the test body was pre-dried at 80°C for 20 minutes to 80 minutes at intervals of 10 minutes. The test body was taken out from the pre-drying furnace, developed under the alkali development conditions of the above test body preparation process, and the removal state of the coating film after development was visually observed. The longest pre-drying time of the test body after the coating film was removed was measured.

[0138] (3) Gold plating

[0139] Plating was performed using a commercially available electroless nickel plating bath and an electroless gold plating bath (Okuno Chemical Industry Co., Ltd.) with a nickel thickness of 0.5 μm and a gold thickness of 0.03 μm. The state of the gold plating was visually observed, and the gold plating properties were evaluated in the following four levels.

[0140] ○: No abnormality on the gold-plated surface.

[0141] △: There is slight unevenness in gold plating.

[0142] ×: The gold plating is uneven as a whole.

[0143] ××: The gold plating is not attached.

[0144] The evaluation results are shown in Table 1 below.

[0145] [Table 1]

[0146]

[0147] As shown in Table 1 above, in Examples 1 to 9 in which a compound having a phenolic hydroxyl group and phosphorus as component (B1) or a compound having a phenolic hydroxyl group and sulfur as component (B2) is added as an antioxidant, a photocured product having excellent sensitivity, and excellent alkali developability and gold plating properties can be obtained. In addition, according to Examples 4 and 7, it can be seen that even if a phenolic antioxidant is used at the same time, a photocured product having excellent sensitivity, and excellent alkali developability and gold plating properties can be obtained. In particular, by comparing Examples 1 to 4 and 8 with Examples 5 to 7 and 9, it can be seen that the compound having a phenolic hydroxyl group and phosphorus as component (B1) can remove the coating film even if the pre-drying time is extended, compared with the compound having a phenolic hydroxyl group and sulfur as component (B2), and the alkali developability is further improved.

[0148] In addition, the sensitivity of Example 2, which contains about 2 parts by mass of the compound (B1) having a phenolic hydroxyl group and phosphorus, is further improved compared with Example 1, which contains about 5 parts by mass of the compound (B1) having a phenolic hydroxyl group and phosphorus, and Example 8, which contains about 10 parts by mass of the compound (B1) having a phenolic hydroxyl group and phosphorus, relative to 100 parts by mass of the carboxyl group-containing photosensitive resin. In addition, the sensitivity of Example 2, which contains about 2 parts by mass of the compound (B1) having a phenolic hydroxyl group and phosphorus, is further improved at 300 mJ / cm compared with Example 4, which contains about 1 part by mass of the compound (B1) having a phenolic hydroxyl group and phosphorus. 2 The gold plating performance is further improved.

[0149] In addition, the alkali developability of Example 5, in which about 1 part by mass of the compound (B2) having a phenolic hydroxyl group and sulfur is mixed with 100 parts by mass of the carboxyl group-containing photosensitive resin, is further improved compared with that of Example 9, in which about 2 parts by mass of the compound (B2) having a phenolic hydroxyl group and sulfur is mixed. In addition, the alkali developability of Example 5, in which about 1 part by mass of the compound (B2) having a phenolic hydroxyl group and sulfur is mixed with 100 parts by mass of the carboxyl group-containing photosensitive resin, is further improved compared with that of Example 6, in which about 0.5 parts by mass of the compound (B2) having a phenolic hydroxyl group and sulfur is mixed with 0.5 parts by mass of the compound (B2) having a phenolic hydroxyl group and sulfur. 2 The gold plating performance is further improved.

[0150] On the other hand, in Comparative Example 1 in which no antioxidant was added, gold plating properties were not obtained, and in Comparative Example 2 in which a phenolic antioxidant was used as an antioxidant and Comparative Example 3 in which a phosphorus antioxidant was used as an antioxidant, no gold plating properties were obtained at 200 mJ / cm 2 、300mJ / cm 2 Gold plating properties.

[0151] Industrial Applicability

[0152] The photosensitive resin composition of the present invention can form a photocured film which has excellent alkali developability, gold plating property and other plating properties without losing its high sensitivity to ultraviolet rays. Therefore, it has high utilization value in the field of protective films such as solder resists formed on printed circuit boards, especially in the field of forming protective films such as solder resists using photosensitive resin compositions that achieve high sensitivity.

Claims

1. A photosensitive resin composition comprising (A) a carboxyl group-containing photosensitive resin, (B) an antioxidant, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound, wherein: The (B) antioxidant contains the (B1) compound having a phenolic hydroxyl group and phosphorus, and contains 2.0 parts by mass or more and 6.0 parts by mass or less of the (B1) compound having a phenolic hydroxyl group and phosphorus relative to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin. The (A) carboxyl group-containing photosensitive resin is a polybasic acid-modified free radical polymerizable unsaturated monocarboxylic acid-modified epoxy resin obtained by reacting a free radical polymerizable unsaturated monocarboxylic acid with at least a portion of the epoxy groups of a multifunctional epoxy resin having two or more epoxy groups in one molecule to obtain a free radical polymerizable unsaturated monocarboxylic acid-modified epoxy resin, and reacting a polybasic acid and / or a polybasic acid anhydride with the generated hydroxyl group.

2. The photosensitive resin composition according to claim 1, wherein The compound (B1) having a phenolic hydroxyl group and phosphorus is a compound of the following formula (1): 。 3. A photosensitive resin composition comprising (A) a carboxyl group-containing photosensitive resin, (B) an antioxidant, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound, wherein: The (B) antioxidant contains the (B2) compound having a phenolic hydroxyl group and sulfur, and contains 0.50 parts by mass or more and 1.5 parts by mass or less of the (B2) compound having a phenolic hydroxyl group and sulfur relative to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin. The (A) carboxyl group-containing photosensitive resin is a polybasic acid-modified free radical polymerizable unsaturated monocarboxylic acid-modified epoxy resin obtained by reacting a free radical polymerizable unsaturated monocarboxylic acid with at least a portion of the epoxy groups of a multifunctional epoxy resin having two or more epoxy groups in one molecule to obtain a free radical polymerizable unsaturated monocarboxylic acid-modified epoxy resin, and reacting a polybasic acid and / or a polybasic acid anhydride with the generated hydroxyl group.

4. The photosensitive resin composition according to claim 3, wherein The compound (B2) having a phenolic hydroxyl group and sulfur is a compound of the following formula (2): 。 5. The photosensitive resin composition according to any one of claims 1 to 4, wherein The (C) photopolymerization initiator contains an oxime ester-based photopolymerization initiator.

6. The photosensitive resin composition according to claim 5, wherein The oxime ester photopolymerization initiator is (Z)-(9-ethyl-6-nitro-9H-carbazol-3-yl)(4-((1-methoxypropane-2-yl)oxy)-2-methylphenyl)methanone O-acetyl oxime. 7 . A photocured material, which is a photocured material of the photosensitive resin composition according to claim 1 . 8 . A dry film comprising the photosensitive resin composition according to claim 1 . 9 . A printed wiring board comprising a photocured product of the photosensitive resin composition according to claim 1 .

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