Photosensitive resin composition

Abstract

The present invention aims to provide a photosensitive resin composition, which can obtain a cured product having excellent coating hardness and high resolution, and has excellent sprayability, viscosity and sensitivity. A photosensitive resin composition, which contains (A) a photosensitive resin, (B) silicon dioxide, (C) a photopolymerization initiator, (D) a reactive diluent and (E) an epoxy compound, wherein the particle size D50 of the silicon dioxide (B) at a cumulative volume percentage of 50% is 0.50 μm or more and 2.00 μm or less.

Description

Technical Field

[0001] The present invention relates to a photosensitive resin composition, for example, a photosensitive resin composition suitable as an insulating protective film of a circuit board and a printed wiring board having a coating obtained by photocuring the photosensitive resin composition. Background Art

[0002] A circuit substrate such as a printed circuit board has a pattern of a conductor circuit formed on the substrate, and electronic components are mounted on the solder pads of the pattern by soldering. The circuit portion other than the solder pads is covered with a solder resist film as a permanent insulating protective film. Thus, when the electronic components are soldered to a circuit substrate such as a printed circuit board, it is possible to prevent solder from adhering to unnecessary portions, and to prevent the circuit conductors from being directly exposed to the air and corroded by oxidation and humidity.

[0003] The insulating protective film covering the circuit board requires coating hardness, and also requires viscosity (touch dryness) during exposure in the insulating protective film forming process. In order to impart excellent coating hardness and viscosity during exposure to the insulating protective film, silica is sometimes added as a filler in a photosensitive resin composition. In order to improve viscosity (touch dryness), as a photosensitive resin composition containing silica, an alkali-developable photosensitive resin composition has been proposed, which contains (A) a carboxyl-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin, and (D) a (meth) acrylic monomer, and (E) spherical silica as an inorganic filler, and contains an acylphosphine oxide-based photopolymerization initiator as the (B) photopolymerization initiator, and contains a bisphenol A novolac-type epoxy resin as the (C) epoxy resin (Patent Document 1).

[0004] On the other hand, in recent years, as the wiring density of printed circuit boards has become finer, the photosensitive resin composition applied as an insulating protective film is also required to have high resolution (high dimensional accuracy) and high precision. However, if silica is added as a filler in the photosensitive resin composition, the resolution of the insulating protective film may not be fully obtained.

[0005] In addition, if silica is added as a filler to the photosensitive resin composition, sufficient sensitivity may not be obtained when the photosensitive resin composition is subjected to a photocuring reaction. In order to achieve excellent efficiency in forming an insulating protective film, the photosensitive resin composition may be applied to the entire surface of the printed circuit board using an electrostatic sprayer, and sprayability may be required for the photosensitive resin composition.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: JP2015-64546A Summary of the invention

[0009] Problems to be solved by the invention

[0010] In view of the above circumstances, an object of the present invention is to provide a photosensitive resin composition which can obtain a cured product having excellent coating film hardness and high resolution and which is excellent in sprayability, viscosity and sensitivity.

[0011] Methods for solving problems

[0012] In the present invention, the silica particles blended in the photosensitive resin composition can form a cured product having excellent coating hardness and resolution by controlling the particle size, and can also obtain a photosensitive resin composition having excellent sprayability, viscosity and sensitivity.

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

[0014] [1] A photosensitive resin composition comprising (A) a photosensitive resin, (B) silica, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound, wherein the particle size D50 of the silica (B) at a cumulative volume percentage of 50% by volume is greater than or equal to 0.50 μm and less than or equal to 2.00 μm.

[0015] [2] The photosensitive resin composition according to [1], wherein the (B) silica is contained in an amount of 2.0 parts by mass or more and 30 parts by mass or less based on 100 parts by mass of the (A) photosensitive resin.

[0016] [3] The photosensitive resin composition according to [1], wherein the (B) silica is contained in an amount of 4.0 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the (A) photosensitive resin.

[0017] [4] The photosensitive resin composition according to any one of [1] to [3], wherein the particle size D50 of the silica (B) at a cumulative volume percentage of 50 volume % is 1.20 μm or more and 1.90 μm or less.

[0018] [5] The photosensitive resin composition according to any one of [1] to [4], wherein the particle size D1.0 of the silica (B) at a cumulative volume percentage of 1.0 volume % is 0.20 μm or more and 0.54 μm or less, and the particle size D99 of the silica (B) at a cumulative volume percentage of 99 volume % is 5.00 μm or more and 8.40 μm or less.

[0019] [6] The photosensitive resin composition according to [4], wherein the particle size D1.0 of the silica (B) at a cumulative volume percentage of 1.0 volume % is greater than 0.40 μm and less than 0.54 μm, and the particle size D99 of the silica (B) at a cumulative volume percentage of 99 volume % is greater than 7.00 μm and less than 8.40 μm.

[0020] [7] The photosensitive resin composition according to any one of [1] to [6], wherein the particle size D10 of the silica (B) at a cumulative volume percentage of 10 volume % is 0.30 μm or more and 0.75 μm or less, and the particle size D90 of the silica (B) at a cumulative volume percentage of 90 volume % is 3.00 μm or more and 5.00 μm or less.

[0021] [8] The photosensitive resin composition according to [4] or [6], wherein the particle size D10 of the silica (B) at a cumulative volume percentage of 10% is 0.50 μm or more and 0.75 μm or less, and the particle size D90 of the silica (B) at a cumulative volume percentage of 90% is 4.00 μm or more and 5.00 μm or less.

[0022] [9] The photosensitive resin composition according to any one of [1] to [8], further comprising (F) other silica having a particle size D50 of less than 0.50 μm in an amount of 50% by volume.

[0023]

[10] The photosensitive resin composition according to any one of [1] to [9], comprising 1.0 part by mass or more and 8.0 parts by mass or less of the (F) other silica per 100 parts by mass of the (A) photosensitive resin.

[0024]

[11] The photosensitive resin composition according to any one of [1] to

[10] , wherein the (E) epoxy compound is at least one epoxy resin selected from a biphenyl-type epoxy resin and a triglycidyl isocyanurate-type epoxy resin.

[0025]

[12] The photosensitive resin composition according to any one of [1] to

[11] , which is used for spray coating.

[0026]

[13] A printed circuit board coated with the photosensitive resin composition according to any one of [1] to

[12] .

[0027] Effects of the Invention

[0028] According to an embodiment of the present invention, the following photosensitive resin composition can be obtained: by containing 50 volume % of silica having a particle size D50 of 0.50 μm or more and 2.00 μm or less, a cured product having excellent coating hardness and high resolution can be formed, and in addition, excellent sprayability, viscosity and sensitivity can be obtained.

[0029] According to the embodiment of the present invention, by containing 2.0 parts by mass or more and 30 parts by mass or less of (B) silica with respect to 100 parts by mass of (A) photosensitive resin, it is possible to reliably improve coating film hardness and viscosity and obtain high resolution and sensitivity.

[0030] According to the embodiment of the present invention, by containing 4.0 parts by mass or more and 20 parts by mass or less of (B) silica with respect to 100 parts by mass of (A) photosensitive resin, coating hardness and viscosity and resolution and sensitivity can be improved in a balanced manner without impairing sprayability.

[0031] According to the embodiment of the present invention, the particle size D50 of (B) silica at a cumulative volume percentage of 50 volume % is 1.20 μm or more and 1.90 μm or less, thereby further improving the coating film hardness, viscosity, resolution, sensitivity and sprayability.

[0032] According to an embodiment of the present invention, by setting the particle size D1.0 of (B) silica, which has a cumulative volume percentage of 1.0 volume %, to be greater than 0.40 μm and less than 0.54 μm, and setting the particle size D99 of (B) silica, which has a cumulative volume percentage of 99 volume %, to be greater than 7.00 μm and less than 8.40 μm, the coating hardness, viscosity, resolution, sensitivity and sprayability can be further improved.

[0033] According to an embodiment of the present invention, by setting the particle size D10 of (B) silica having a cumulative volume percentage of 10 volume % to be greater than 0.50 μm and less than 0.75 μm, and setting the particle size D90 of (B) silica having a cumulative volume percentage of 90 volume % to be greater than 4.00 μm and less than 5.00 μm, the coating hardness, viscosity, resolution, sensitivity and sprayability can be further improved.

[0034] According to an embodiment of the present invention, by further containing (F) 50% by volume of other silica having a particle size D50 of less than 0.50 μm, it is possible to contribute to improving the coating film hardness, viscosity, resolution, sensitivity and sprayability.

[0035] According to the embodiment of the present invention, by containing 1.0 to 8.0 parts by mass of (F) other silica per 100 parts by mass of (A) photosensitive resin, it is possible to reliably contribute to further improvement of coating film hardness, viscosity, resolution, sensitivity and sprayability. DETAILED DESCRIPTION

[0036] Next, the photosensitive resin composition of the present invention is described below. The photosensitive resin composition of the present invention contains (A) a photosensitive resin, (B) silica, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound, wherein the particle size D50 of the silica (B) at a cumulative volume percentage of 50% is 0.50 μm or more and 2.00 μm or less.

[0037] (A) Photosensitive resin

[0038] The structure of the photosensitive resin of the component (A) is not particularly limited, and for example, a resin having one or more photosensitive unsaturated double bonds can be cited. In addition, as the photosensitive resin, a carboxyl-containing photosensitive resin having one or more photosensitive unsaturated double bonds and a free carboxyl group 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) acrylate can be cited as follows: free radical polymerizable unsaturated monocarboxylic acid such as acrylic acid, methacrylic acid (hereinafter, sometimes referred to as "(meth) acrylic acid") is reacted with at least a part of the epoxy group of a multifunctional epoxy resin having two or more epoxy groups in one molecule, thereby obtaining a free radical polymerizable unsaturated monocarboxylic acid epoxy resin such as epoxy (meth) acrylate, and the polyacid and / or its anhydride is reacted with the hydroxyl group of the generated free radical polymerizable unsaturated monocarboxylic acid epoxy resin.

[0039] 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 is preferably 3000 g / eq, more preferably 2000 g / eq, and particularly preferably 1500 g / eq. On the other hand, the lower limit is preferably 100 g / eq, and particularly preferably 200 g / eq.

[0040] As the resin type of the multifunctional epoxy resin, for example, there can be enumerated 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 resins such as silicone modified epoxy resin, ε-caprolactone modified epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resins such as o-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, epoxy resins obtained by further introducing halogen atoms such as Br and Cl into 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.

[0041] The chemical structure of 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 easy 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.

[0042] 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.

[0043] The polyacid and / or polyacid anhydride react with the hydroxyl group generated by the reaction of the polyfunctional 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 may be any saturated or unsaturated structure. 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.

[0044] 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. For example, there can be mentioned 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.

[0045] The polyacid-modified unsaturated monocarboxylic acid epoxy resin can also be used as a photosensitive resin (carboxyl group-containing photosensitive resin), but a polyacid-modified free radical polymerizable unsaturated monocarboxylic acid epoxy resin to which a free radical polymerizable unsaturated group is further added, which is obtained by addition reaction of a compound having one or more free radical polymerizable unsaturated groups and epoxy groups with a part of the carboxyl groups of the polyacid-modified unsaturated monocarboxylic acid epoxy resin obtained in the above manner, can also be used as a photosensitive resin. The polyacid-modified free radical polymerizable unsaturated monocarboxylic acid epoxy resin to which a free radical polymerizable unsaturated group is further added 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 photosensitive resin (carboxyl group-containing photosensitive resin) having a further improved photosensitivity compared to the polyacid-modified unsaturated monocarboxylic acid epoxy resin.

[0046] 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. A molecule may have one glycidyl group or may have multiple glycidyl groups. In addition, the above-mentioned compounds having one or more free radical polymerizable unsaturated groups and epoxy groups may be used alone or in combination of two or more.

[0047] The method for reacting the polyacid-modified unsaturated monocarboxylic acid epoxy resin with the compound having one or more free radical polymerizable unsaturated groups and epoxy groups is not particularly limited. For example, there can be cited a method in which the polyacid-modified unsaturated monocarboxylic acid epoxy resin and the 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.

[0048] In addition, as the photosensitive resin, a photosensitive resin without a free carboxyl group can be used. As the photosensitive resin without a free carboxyl group, a polymer of a monomer composed of (meth)acrylate, epoxy (meth)acrylate obtained by reacting (meth)acrylic acid with an epoxy resin, urethane (meth)acrylate, etc. can be cited.

[0049] As epoxy (meth) acrylate, epoxy (meth) acrylate obtained in the preparation process of the above-mentioned carboxyl-containing photosensitive resin can be cited. For carbamate (meth) acrylate, for example, carbamate (meth) acrylate obtained by reacting (meth) acrylic acid with polyurethane resin can be cited. Polyurethane resin is a resin obtained by reacting a compound having two or more isocyanate groups in one molecule with a polyol compound having two or more hydroxyl groups in one molecule. In addition, for carbamate (meth) acrylate, for example, the following carbamate (meth) acrylate can be cited: epoxy (meth) acrylate is obtained by reacting (meth) acrylic acid with at least a part of the epoxy groups of an epoxy resin having one or more epoxy groups in one molecule, and the above-mentioned carbamate (meth) acrylate is obtained by allowing a compound having one or more isocyanate groups in one molecule to undergo an addition reaction with the generated hydroxyl group.

[0050] When the photosensitive resin contains a carboxyl group, the acid value of the photosensitive resin is not particularly limited. For example, from the perspective of reliably obtaining alkali developability, 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.

[0051] The mass average molecular weight of the photosensitive resin is not particularly limited. For example, from the perspective of the toughness of the photocured material, the lower limit is preferably 6000, more preferably 7000, and particularly preferably 8000. On the other hand, from the perspective of compatibility with the non-reactive diluent described later, the upper limit of the mass average molecular weight of the photosensitive resin is preferably 200000, more preferably 100000, and particularly preferably 50000. In addition, the "mass average molecular weight" refers to the mass average molecular weight measured at room temperature by gel permeation chromatography (GPC) and calculated by polystyrene conversion.

[0052] The photosensitive resin can be prepared by using the above-mentioned components through the above-mentioned reaction process, or a commercially available photosensitive resin can be used. Commercially available photosensitive resins include, for example, carboxyl group-containing photosensitive resins such as "SP-4621" (Showa Denko K.K.), "KAYARAD ZAR-2000", "KAYARAD ZFR-1122", "KAYARAD FLX-2089", "KAYARAD ZCR-1569H" (all from Nippon Kayaku Co., Ltd.), and "Cyclomer P (ACA) Z-250" (Daicel Allnex Ltd.). In addition, the above-mentioned photosensitive resins can be used alone, or two or more of the above-mentioned photosensitive resins can be used simultaneously.

[0053] (B) Silica having a particle size D50 of 0.50 μm or more and 2.00 μm or less as a cumulative volume percentage of 50 volume%

[0054] By adding silica as component (B) with a cumulative volume percentage of 50% by volume and a particle size D50 of 0.50 μm or more and 2.00 μm or less, a photosensitive resin composition can be obtained: it can form a cured product with excellent coating hardness and high resolution, and it is excellent in sprayability, viscosity and sensitivity.

[0055] Regarding silica, as long as the particle size D50 (hereinafter, sometimes referred to as "D50") with a cumulative volume percentage of 50% by volume is 0.50 μm or more and 2.00 μm or less, the particle size and particle size distribution of silica are not particularly limited. From the perspective of further improving the hardness, viscosity, resolution, sensitivity and sprayability of the coating film, the lower limit of D50 is preferably 1.00 μm, and particularly preferably 1.20 μm. On the other hand, from the perspective of further improving the hardness, viscosity, resolution, sensitivity and sprayability of the coating film, the upper limit of D50 is preferably 1.95 μm, more preferably 1.90 μm, and particularly preferably 1.80 μm.

[0056] As for silica, as long as D50 is 0.50 μm or more and 2.00 μm or less, there is no particular limitation on the particle size D1.0 (hereinafter, sometimes referred to as "D1.0") at which the cumulative volume percentage of silica is 1.0 volume % and the particle size D99 (hereinafter, sometimes referred to as "D99") at which the cumulative volume percentage of silica is 99 volume %. From the perspective of reliably improving the hardness and viscosity of the coating film and obtaining high resolution and sensitivity, the lower limit of D1.0 is preferably 0.20 μm, and from the perspective of further improving the hardness, viscosity, resolution, sensitivity and sprayability of the coating film, it is more preferably 0.40 μm, and particularly preferably 0.45 μm. On the other hand, from the perspective of further improving the hardness, viscosity, resolution, sensitivity and sprayability of the coating film, the upper limit of D1.0 is preferably 0.54 μm, and particularly preferably 0.53 μm. In addition, from the perspective of reliably improving the coating hardness and viscosity and obtaining high resolution and sensitivity, the lower limit of D99 is preferably 5.00 μm, and from the perspective of further improving the coating hardness, viscosity, resolution, sensitivity and sprayability, it is more preferably 7.00 μm, and particularly preferably 7.50 μm. On the other hand, from the perspective of further improving the coating hardness, viscosity, resolution, sensitivity and sprayability, the upper limit of D99 is preferably 8.40 μm, and particularly preferably 8.35 μm.

[0057] As for silica, as long as D50 is 0.50 μm or more and 2.00 μm or less, there is no particular limitation on the particle size D10 (hereinafter, sometimes referred to as "D10") at which the cumulative volume percentage of silica is 10% by volume and the particle size D90 (hereinafter, sometimes referred to as "D90") at which the cumulative volume percentage of silica is 90% by volume. From the perspective of reliably improving the hardness and viscosity of the coating film and obtaining high resolution and sensitivity, the lower limit of D10 is preferably 0.30 μm, and from the perspective of further improving the hardness, viscosity, resolution, sensitivity and sprayability of the coating film, it is more preferably 0.50 μm, and particularly preferably 0.60 μm. On the other hand, from the perspective of further improving the hardness, viscosity, resolution, sensitivity and sprayability of the coating film, the upper limit of D10 is preferably 0.75 μm, and particularly preferably 0.70 μm. In addition, from the perspective of reliably improving the coating hardness and viscosity and obtaining high resolution and sensitivity, the lower limit of D90 is preferably 3.00 μm, and from the perspective of further improving the coating hardness, viscosity, resolution, sensitivity and sprayability, it is more preferably 4.00 μm, and particularly preferably 4.30 μm. On the other hand, from the perspective of further improving the coating hardness, viscosity, resolution, sensitivity and sprayability, the upper limit of D90 is preferably 5.00 μm, and particularly preferably 4.90 μm.

[0058] In addition, the above-mentioned D1.0, D10, D50, D90, and D99 represent the cumulative distribution on a volume basis when the particle size distribution of silica is measured using a laser particle size analyzer based on JIS Z 8825-1, and represent the particle size from the small diameter side of the particle size distribution to 1.0 volume%, the particle size from the small diameter side of the particle size distribution to 10 volume%, the particle size from the small diameter side of the particle size distribution to 50 volume%, the particle size from the small diameter side of the particle size distribution to 90 volume%, and the particle size from the small diameter side of the particle size distribution to 99 volume%.

[0059] The particle shape of silica is not particularly limited, and a spherical shape is an example. The silica may be silica that has not been subjected to surface treatment (untreated silica) or may be surface-treated silica with a coating of an organic compound or the like formed on the surface.

[0060] The content of silica having a D50 of not less than 0.50 μm and not more than 2.00 μm is not particularly limited. For example, from the perspective of reliably improving the hardness and viscosity of the coating film and obtaining high resolution and sensitivity, the lower limit is preferably 2.0 parts by mass relative to 100 parts by mass (solid content (resin amount), the same below) of the photosensitive resin. From the perspective of being able to improve the hardness and viscosity of the coating film and the resolution and sensitivity in a balanced manner without impairing the sprayability, it is more preferably 4.0 parts by mass. From the perspective of further improving the sprayability, it is particularly preferably 8.0 parts by mass. On the other hand, from the perspective of reliably improving resolution and sensitivity and obtaining high coating hardness and viscosity, the upper limit of the content of silica with D50 of 0.50 μm or more and 2.00 μm or less relative to 100 parts by mass of photosensitive resin is preferably 30 parts by mass, from the perspective of being able to balance the improvement of coating hardness and viscosity and resolution and sensitivity without impairing sprayability, it is more preferably 20 parts by mass, and from the perspective of further improving sensitivity and sprayability, it is particularly preferably 15 parts by mass.

[0061] (C) Photopolymerization initiator

[0062] 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 1,8-bis(O-acetyl)-1,8-dione, 1,8-bis[9-(2-ethylhexyl)-6-nitro-9H-carbazole-3-yl]-, 1,8-bis(O-acetyl)-1,8-dione, (Z)-(9-ethyl-6-nitro-9H-carbazole-3-yl)(4-((1-methoxypropane-2-yl)oxy)-2-methylphenyl)methanone O-acetyloxime. 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- ... 1-Hydroxy-2-methyl-1-phenylpropanone, 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.

[0063] The content of the photopolymerization initiator is not particularly limited, but is preferably 5 to 40 parts by mass, particularly preferably 10 to 30 parts by mass, based on 100 parts by mass of the photosensitive resin.

[0064] (D) Reactive diluent

[0065] 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 to improve the hardness, acid resistance, heat resistance, and alkali resistance of the photocured product.

[0066] 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, adipic acid neopentyl glycol di(meth)acrylate, hydroxypivalic acid 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 (meth)acrylate, 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, etc. These compounds may be used alone or in combination of two or more thereof.

[0067] The content of the reactive diluent is not particularly limited, but is preferably 10 to 100 parts by mass, and particularly preferably 20 to 50 parts by mass, based on 100 parts by mass of the photosensitive resin.

[0068] (E) Epoxy compounds

[0069] The epoxy compound as component (E) is used to obtain the crosslinking density of the photocured product by increasing the photosensitive resin composition, thereby contributing to improving the mechanical strength of the photocured product. As an epoxy compound, for example, epoxy resin can be cited. As an epoxy resin, for example, bisphenol F type epoxy resins such as biphenyl type epoxy resins, biphenyl aralkyl type epoxy resins, bisphenol A type epoxy resins, tetramethyl bisphenol F type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, dicyclopentadiene type epoxy resins, adamantane type epoxy resins, isocyanuric acid triglycidyl ester type epoxy resins, etc. can be cited. Among them, from the aspect of further improving the application period, 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. Among these resins, from the aspect of further improving the coating film hardness, preferably isocyanuric acid triglycidyl ester type epoxy resin. The above compounds may be used alone or in combination of two or more.

[0070] The content of the epoxy compound is not particularly limited, but is preferably 10 parts by mass or more and 100 parts by mass or less, and particularly preferably 20 parts by mass or more and 50 parts by mass or less, based on 100 parts by mass of the photosensitive resin.

[0071] In the photosensitive resin composition of the present invention, in addition to the above-mentioned components (A) to (E), a silica having a particle size D50 of less than 0.50 μm (hereinafter sometimes referred to as "other silica") in an amount of 50% by volume may be added as needed. Other silica contributes to the improvement of the hardness, viscosity, resolution, sensitivity and sprayability of the coating film.

[0072] The D50 of the other silica as the component (F) is not particularly limited as long as it is less than 0.50 μm, but is preferably less than 0.30 μm, and particularly preferably less than 0.10 μm. As other silica, for example, fumed silica can be cited. Fumed silica can be hydrophobic fumed silica or hydrophilic fumed silica.

[0073] The content of other silicon dioxide is not particularly limited, but the lower limit is preferably 1.0 parts by mass, and particularly preferably 2.0 parts by mass, relative to 100 parts by mass of the photosensitive resin, from the perspective of reliably contributing to further improvement of the hardness, viscosity, resolution, sensitivity, and sprayability of the coating film. On the other hand, the upper limit of the content of other silicon dioxide is preferably 15 parts by mass, and particularly preferably 8.0 parts by mass, relative to 100 parts by mass of the photosensitive resin, from the perspective of reliably contributing to further improvement of the hardness, viscosity, resolution, sensitivity, and sprayability of the coating film.

[0074] The photosensitive resin composition of the present invention may contain other components such as extender pigments, colorants (color pigments), additives, non-reactive diluents, etc., in addition to the above-mentioned components (A) to (F), as required.

[0075] As body pigments, talc, barium sulfate, hydrophobic silica, aluminum oxide, aluminum hydroxide, mica, etc. can be cited. The colorant is not particularly limited to pigments, pigments, etc., and colorants of any color such as white colorants, blue colorants, green colorants, yellow colorants, purple colorants, black colorants, and orange colorants can also be used. As for the above-mentioned colorants, for example, titanium oxide (rutile type, anatase type) as a white colorant, carbon black, acetylene black and other inorganic colorants as black colorants, phthalocyanine green as a green colorant, phthalocyanine blue, Lionol blue and other phthalocyanines as blue colorants, anthraquinones as yellow colorants, diketopyrrolopyrroles such as Chromophthal orange and other organic colorants as orange colorants can be cited.

[0076] As for additives, for example, 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, curing accelerators such as amine imide (AI) and polyamines, metal salts of acetylacetone such as zinc acetylacetonate and chromium acetylacetonate, enamine, tin octoate, quaternary sulfonium salts, triphenylphosphine, imidazoles such as 2-mercaptobenzimidazole, thermosetting accelerators such as imidazolium salts and triethanolamine borate, and thixotropic agents such as polycarboxylic acid amides.

[0077] 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, xylene, and tetramethylbenzene; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; carbitols such as methyl carbitol and butyl carbitol; glycol ethers such as propylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and esters of the above glycol ethers; alcohols such as ethanol, propanol, cyclohexanol, ethylene glycol, and propylene glycol. The above compounds may be used alone or in combination of two or more thereof.

[0078] 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 kneading or mixing.

[0079] Next, an example of a method of using the photosensitive resin composition of the present invention will be described. Here, a method of spraying the photosensitive resin composition of the present invention on a printed wiring board to form an insulating film such as a solder resist film will be described as an example.

[0080] The photosensitive resin composition of the present invention manufactured in the above manner is applied to a printed circuit board with a desired thickness, for example, 5 μm to 100 μm, by a sprayer to form a coating film. As a spraying method, it can be appropriately selected, for example, an electrostatic sprayer, an air sprayer, an airless sprayer, etc. can be cited. After spraying the photosensitive resin composition, pre-drying is performed at a temperature of about 60°C to 100°C for about 15 minutes to 60 minutes as required, thereby forming a non-sticky coating film. Next, a negative film having a light-transmitting pattern other than the pads of the circuit pattern is closely attached to the coating film, and ultraviolet rays (for example, a wavelength in the range of 300nm to 400nm) are irradiated from above the negative film to photocure the coating film. Next, the non-exposed area corresponding to the pad is removed by a dilute alkali aqueous solution to develop the coating film. For the development method, a spraying method, a shower method, etc. are adopted, and as the dilute alkali aqueous solution used, for example, a 0.5% to 5% sodium carbonate aqueous solution can be cited. Next, post-curing (main 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 target solder resist film can be formed on the printed wiring board.

[0081] Example

[0082] Next, examples of the present invention will be described, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

[0083] Examples 1 to 8, Comparative Examples 1 to 3

[0084] The components shown in Table 1 below were mixed in the mixing ratio shown in Table 1 below, and they were mixed and dispersed at room temperature (25° C.) using a triple roll to prepare the photosensitive resin compositions used in Examples 1 to 8 and Comparative Examples 1 to 3. Unless otherwise specified, the mixing amount of each component shown in Table 1 below is expressed as parts by mass. In addition, the blank part of the mixing amount in Table 1 below indicates that the component is not mixed.

[0085] The details of the components in Table 1 below are as follows.

[0086] (A) Photosensitive resin

[0087] 220 parts by mass of a cresol novolac epoxy resin (ESCN-220 manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent: 220) and 72 parts by mass of acrylic acid were dissolved in 250 parts by mass of carbitol acetate and reacted under reflux to obtain a cresol novolac epoxy acrylate. Next, 138.6 parts by mass of hexahydrophthalic anhydride was added to the obtained cresol novolac epoxy acrylate and reacted under reflux until the acid value reached the theoretical value, and then 56.8 parts by mass of glycidyl methacrylate was added and further reacted to obtain a synthetic resin (A-1) of a carboxyl group-containing photosensitive resin having a solid content of 65% by mass.

[0088] (B) Silica having a D50 of 0.50 μm or more and 2.00 μm or less

[0089] SilvorBond 925: SEBELCO

[0090] (C) Photopolymerization initiator

[0091] ·Irgacure 369: Ciba Specialty Chemicals Co., Ltd.

[0092] ·NCI-831: ADEKA Co., Ltd.

[0093] (D) Reactive diluent

[0094] ·DPHA: Toa Gosei Co., Ltd.

[0095] (E) Epoxy compounds

[0096] ·YX-4000K: Mitsubishi Chemical Corporation

[0097] TEPIC-H: Nissan Chemical Industries, Ltd.

[0098] (F) Silica with D50 less than 0.50 μm

[0099] ·AEROSIL R974: Japan AEROSIL Co., Ltd., D50 is 12nm

[0100] Extender Pigment

[0101] ·Barium sulfate B-30: Sakai Chemical Industry Co., Ltd.

[0102] ·FH105: Fuji Talc Co., Ltd.

[0103] Colorants

[0104] ·Chromophthal Yellow AGR: Ciba Specialty Chemicals Co., Ltd.

[0105] ·Lionol Blue FG-7351: TOYOCOLOR CO.,LTD.

[0106] additive

[0107] Melamine: Nissan Chemical Co., Ltd.

[0108] DICY-7: Japan Epoxy Resin Co., Ltd.

[0109] ·Antage MB: Kawaguchi Chemical Industry Co., Ltd.

[0110] BYK-405: BYK Chemicals

[0111] Non-reactive diluent

[0112] ·Diethylene glycol monoethyl ether acetate: Sanyo Chemicals Co., Ltd.

[0113] Silicon dioxide with a D50 exceeding 2.00 μm

[0114] ·MINUSIL 5:Air-Brown Co.,Ltd.

[0115] Test body production process

[0116] Substrate: Printed wiring board (glass epoxy substrate "FR-4", board thickness 1.6mm, conductor (Cu foil) thickness 50μm)

[0117] Substrate surface treatment: polishing and grinding

[0118] Coating: screen spraying

[0119] Coating conditions: discharge volume (110cc / min), conveyor speed (2.3m / min), turntable speed (30000rpm), applied voltage (-35KV)

[0120] Dry film thickness: 35μm~40μm, wet film thickness: spraying 70μm~80μm

[0121] Pre-drying: 80℃, 20 minutes

[0122] Exposure: 100mJ / cm on photosensitive resin composition 2 (ORC MANUFACTURING CO.,LTD. "HMW-680GW")

[0123] Alkali developer: 1% Na 2 CO 3 , liquid temperature is 30℃, injection pressure is 0.2MPa, development time is 60 seconds, post-curing (main curing treatment): 150℃, 60 minutes,

[0124] The evaluation items are as follows.

[0125] (1) Resolution (dimensional accuracy)

[0126] The line width of the exposed portion of the photosensitive resin composition formed on the Cu foil through a photomask (line 100 μm) was measured using an optical microscope (50 times), and evaluated based on the following criteria.

[0127] ◎: Line width less than 105μm

[0128] ○: Line width is 105 μm or more and less than 110 μm

[0129] △: Line width is 110 μm or more and less than 115 μm

[0130] ×: Line width is 115 μm or more

[0131] (2) Pencil hardness

[0132] The pencil hardness of the cured coating film on the Cu foil of the substrate was evaluated according to the test method of JIS K-5600-5-4.

[0133] ◎: 7 hours or more

[0134] ○: 5 hours or more and 6 hours or less

[0135] △: 3 hours or more and 4 hours or less

[0136] ×: 2 hours or less

[0137] (3) Viscosity

[0138] The adhesion to the coating film when the negative film was brought into contact with the coating film and exposed after preliminary drying was evaluated based on the following criteria.

[0139] ◎: Not attached to the coating film

[0140] ○: Slightly adheres to the coating film, but no trace of adhesion on the coating film

[0141] △: There are traces of adhesion left on the coating film

[0142] ×: After the negative film is peeled off from the coating film, the negative film has adhesion of the coating film

[0143] (4) Sensitivity

[0144] After pre-drying at 80°C for 20 minutes, the coated substrate was placed on a step exposure meter for sensitivity measurement (Kodak, 21 steps), and the step exposure meter was used to irradiate the substrate with a light intensity of 100 mJ / cm 2 The test piece was prepared by irradiating ultraviolet rays with a main peak wavelength of 365nm, and the unremoved portion of the exposed portion after development using a 1 mass % sodium carbonate aqueous solution at a splash pressure of 0.2 MPa and a development time of 60 seconds was represented by numbers (grades) and evaluated based on the following criteria.

[0145] ◎: Level 9 and above

[0146] ○: Level 7-8

[0147] △: Level 5-6

[0148] ×: Level 4 or below

[0149] (5) Sprayability

[0150] The surface appearance of the coating film after the preliminary drying was visually observed and evaluated based on the following criteria.

[0151] ◎: No bubbles or orange peel, good leveling

[0152] ○: Orange peel is slightly present, or the coating near the Cu foil is slightly thin

[0153] △: The coating surface has slightly lost its gloss with a slight appearance of orange peel

[0154] ×: Orange peel appears or cannot be sprayed

[0155] The results of the above evaluation are shown in Table 1 below.

[0156] [Table 1]

[0157]

[0158] As shown in Table 1 above, in Examples 1 to 8 in which silica having a D50 of 0.50 μm or more and 2.00 μm or less was added as the (B) component, a photosensitive resin composition was obtained that was capable of forming a cured product having excellent coating film hardness and high resolution and had excellent sprayability, viscosity and sensitivity. Regarding Example 3, in which approximately 12 parts by mass of silica having a D50 of 0.50 μm or more and 2.00 μm or less is added to 100 parts by mass of photosensitive resin (solid content (resin amount), the same below), the coating hardness, viscosity and sprayability are further improved compared to Example 1, in which approximately 2.4 parts by mass of silica having a D50 of 0.50 μm or more and 2.00 μm or less is added to 100 parts by mass of photosensitive resin, and the sprayability is further improved compared to Example 2, in which approximately 4.8 parts by mass of silica having a D50 of 0.50 μm or more and 2.00 μm or less is added to 100 parts by mass of photosensitive resin.

[0159] In addition, regarding Example 3, in which approximately 12 parts by mass of silica having a D50 of 0.50 μm or more and 2.00 μm or less as component (B) is added to 100 parts by mass of photosensitive resin, the resolution, sensitivity, and sprayability are further improved compared to Example 5, in which approximately 29 parts by mass of silica having a D50 of 0.50 μm or more and 2.00 μm or less as component (B) is added to 100 parts by mass of photosensitive resin, and the sensitivity and sprayability are further improved compared to Example 4, in which approximately 19 parts by mass of silica having a D50 of 0.50 μm or more and 2.00 μm or less as component (B) is added to 100 parts by mass of photosensitive resin.

[0160] In addition, regarding Example 2, in which about 2.4 parts by mass of silica having a D50 of less than 0.50 μm as the (F) component is mixed with respect to 100 parts by mass of the photosensitive resin, the resolution, coating hardness, viscosity, sensitivity, and sprayability are further improved compared to Example 6, in which about 9.6 parts by mass of silica having a D50 of less than 0.50 μm as the (F) component is mixed with respect to 100 parts by mass of the photosensitive resin. In addition, regarding Example 3, in which silica having a D50 of 1.75 μm is used as the (B) component, the resolution, coating hardness, viscosity, sensitivity, and sprayability are further improved compared to Example 7, in which silica having a D50 of 1.12 μm is used as the (B) component. In addition, Example 8, in which triglycidyl isocyanurate type epoxy resin is used as the (E) component (i.e., epoxy compound), the coating hardness is further improved compared to Example 3, in which a biphenyl type epoxy resin is used.

[0161] On the other hand, as shown in Table 1, Comparative Examples 1 to 3 using silica having a D50 of 2.09 μm instead of silica having a D50 of 0.50 μm to 2.00 μm failed to achieve at least one characteristic of resolution, coating hardness, and sensitivity.

[0162] Industrial Applicability

[0163] The photosensitive resin composition of the present invention can form a cured product having excellent coating hardness and high resolution, and can also obtain a photosensitive resin composition having excellent sprayability, viscosity and sensitivity. Therefore, it has high utilization value in the field of insulating coatings for printed circuit boards such as solder resist films.

Claims

1. A photosensitive resin composition comprising (A) a photosensitive resin, (B) silicon dioxide, (C) a photopolymerization initiator, (D) a reactive diluent and (E) an epoxy compound, in, The particle size D50 of the silicon dioxide (B) at a cumulative volume percentage of 50% by volume is 1.20 μm or more and 1.80 μm or less, The (B) silica is contained in an amount of 2.0 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of the (A) photosensitive resin, The invention further comprises 1.0 to 8.0 parts by mass of (F) other silica having a particle size D50 of less than 0.50 μm in an amount of 50% by volume based on 100 parts by mass of the (A) photosensitive resin. The silica blended in the photosensitive resin composition is the (B) silica and the (F) other silica.

2. The photosensitive resin composition according to claim 1, wherein The (B) silica is contained in an amount of 4.0 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the (A) photosensitive resin.

3. The photosensitive resin composition according to claim 1 or 2, wherein The particle size D1.0 of the silica (B) at a cumulative volume percentage of 1.0 volume % is 0.20 μm or more and 0.54 μm or less, and the particle size D99 of the silica (B) at a cumulative volume percentage of 99 volume % is 5.00 μm or more and 8.40 μm or less.

4. The photosensitive resin composition according to claim 1 or 2, wherein The particle size D1.0 of the silica (B) at a cumulative volume percentage of 1.0 volume % is 0.40 μm or more and 0.54 μm or less, and the particle size D99 of the silica (B) at a cumulative volume percentage of 99 volume % is 7.00 μm or more and 8.40 μm or less.

5. The photosensitive resin composition according to claim 1 or 2, wherein The particle size D10 of the silica (B) at a cumulative volume percentage of 10% is 0.30 μm to 0.75 μm, and the particle size D90 of the silica (B) at a cumulative volume percentage of 90% is 3.00 μm to 5.00 μm.

6. The photosensitive resin composition according to claim 1 or 2, wherein The particle size D10 of the silica (B) at a cumulative volume percentage of 10% is 0.50 μm to 0.75 μm, and the particle size D90 of the silica (B) at a cumulative volume percentage of 90% is 4.00 μm to 5.00 μm.

7. The photosensitive resin composition according to claim 3, wherein The particle size D10 of the silica (B) at a cumulative volume percentage of 10% is 0.50 μm to 0.75 μm, and the particle size D90 of the silica (B) at a cumulative volume percentage of 90% is 4.00 μm to 5.00 μm.

8. The photosensitive resin composition according to claim 1 or 2, wherein The (E) epoxy compound is at least one epoxy resin selected from the group consisting of biphenyl epoxy resins and triglycidyl isocyanurate epoxy resins.

9. The photosensitive resin composition according to claim 1, wherein The (B) silica is contained in an amount of 8.0 parts by mass or more and 15 parts by mass or less based on 100 parts by mass of the (A) photosensitive resin.

10. The photosensitive resin composition according to claim 1 or 2, wherein The (E) epoxy compound is a triglycidyl isocyanurate type epoxy resin. The photosensitive resin composition according to claim 1 or 2, which is used for spray coating.

12. A printed circuit board coated with the photosensitive resin composition according to claim 1 or 2.

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