Photosensitive resin composition, dry film, cured product, and printed wiring board

Abstract

To provide a photosensitive resin composition that, even when formed as a thick coating film, exhibits superior resolution while retaining superior blackness and hiding ability.SOLUTION: A photosensitive resin composition comprises at least: (A) an alkali-soluble resin; (B) a photopolymerization initiator; (C) a colorant; and (D) a photopolymerizable monomer, wherein the (C) colorant includes: (C1) carbon black; (C2) a perylene-based violet colorant; (C3) a blue colorant; and (C4) a yellow or orange colorant.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a photosensitive resin composition, and more specifically to a black photosensitive resin composition that can be suitably used for forming an insulating layer such as a solder resist, a dry film using the photosensitive resin composition, a cured product of the photosensitive resin composition or the dry film, and a printed wiring board using these cured products. [Background technology]

[0002] In general, when mounting electronic components on a printed wiring board used in electronic devices, a resin composition is applied to the area of ​​the board on which the circuit pattern is formed, except for the connection holes, or a dry coating film is laminated on a dry film, and then hardened to form a solder resist. This solder resist prevents solder from adhering to unnecessary areas and protects the conductors of the circuit. Solder resist also plays a role in preventing deterioration of the appearance of the printed wiring board by concealing discoloration of the circuit pattern due to heat or moisture, electrical discoloration, scratches, dirt, etc. Therefore, in order to improve concealment, a colorant is usually added to the resin composition or dry film used to form the solder resist (for example, Patent Document 1, etc.).

[0003] In recent years, in response to the demand for smaller electronic devices and higher performance, the circuit patterns of printed wiring boards have become finer, and accordingly, solder resists have become thinner. As a result, the concealing ability of the solder resist may decrease, leading to poor appearance. For this reason, it has been proposed to improve the concealing ability by using a black solder resist. In addition, black solder resists are sometimes used to impart design appeal.

[0004] As a photosensitive resin composition used for the above-mentioned applications, a black photosensitive resin composition containing a black colorant such as carbon black is known (for example, Patent Document 2). However, a photosensitive resin composition with excellent concealing properties also has a low light transmittance, so the resolution of patterning during exposure tends to decrease. Therefore, the higher the resolution of parts becomes, the more difficult it is to meet the demands of conventional black photosensitive resin compositions. In addition, the thicker the coating film of a black photosensitive resin composition, the worse the curing property in the deeper parts tends to be.

[0005] In response to the above problems, a black curable resin composition has been proposed that uses a specific organic coloring pigment to ensure the transmittance of light (wavelengths in the ultraviolet region) during exposure while maintaining low light transmittance in the visible light region. For example, a photosensitive resin composition has been proposed that can maintain photocurability in the depths even when the black color is darkened by using two or more colored colorants in combination without using a colorant such as carbon black (Patent Document 3). In addition, it has been proposed to improve photosensitivity in a black photosensitive resin composition containing a black colorant such as carbon black, perylene black, aniline black, or titanium black by using an acylphosphine oxide-based photopolymerization initiator, an α-aminoalkylphenone-based photopolymerization initiator, an oxime ester-based photopolymerization initiator, or the like as a photopolymerization initiator (Patent Document 4). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-258613 A [Patent Document 2] JP 2008-257045 A [Patent Document 3] JP 2010-091876 A [Patent Document 4] JP 2022-154993 A Summary of the Invention [Problem to be solved by the invention]

[0007] The black curable resin compositions proposed in the above-mentioned patent documents are black in color and have excellent resolution. However, in cases where a thick solder resist (e.g., 40 μm or more) is required, the resolution deteriorates, and it has been necessary to lower the optical density.

[0008] Therefore, an object of the present invention is to provide a photosensitive resin composition which maintains excellent blackness and hiding power and also has excellent resolution even when applied to form a thick coating film. [Means for solving the problem]

[0009] The present inventors have conducted research into the above-mentioned problems, and have found that by using three specific colorants in addition to carbon black as a black colorant, a photosensitive resin composition that maintains excellent blackness and hiding power and also has excellent resolution, even when a thick coating film is formed, can be realized. The present invention is based on this finding. That is, the gist of the present invention is as follows.

[0010] [1] A photosensitive resin composition comprising at least (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a colorant, and (D) a photopolymerizable monomer, The colorant (C) is (C1) carbon black, (C2) a perylene-based purple colorant; (C3) a blue colorant; (C4) a yellow or orange colorant; A photosensitive resin composition comprising: [2] The photosensitive resin composition according to [1], wherein the blue colorant (C3) contains a pigment having a phthalocyanine skeleton. [3] The photosensitive resin composition according to [1] or [2], wherein the (C4) yellow or orange colorant contains a pigment having a skeleton selected from the group consisting of an anthraquinone skeleton and a diketopyrrolopyrrole skeleton. [4] The photosensitive resin composition according to any one of [1] to [3], wherein the (B) photopolymerization initiator contains a titanocene-based photopolymerization initiator. [5] The photosensitive resin composition according to any one of [1] to [4], wherein a ratio of a total content of the colorants (C2), (C3), and (C4) to a content of the carbon black (C1) is 20:1 to 80:1. [6] The photosensitive resin composition according to any one of [1] to [5], wherein the (C) colorant is contained in an amount of 1 to 4 mass % based on the total solid content of the photosensitive resin composition. [7] A dry film comprising: a first film; and a resin layer formed by applying the photosensitive resin composition according to any one of [1] to [6] on one surface of the first film and drying the composition. [8] A cured product obtained by curing the resin layer of the photosensitive resin composition according to any one of [1] to [6] or the dry film according to [7]. [9] A printed wiring board having a coating made of the cured product described in [8]. Effect of the Invention

[0011] According to the present invention, by using three specific colorants in addition to carbon black as a black colorant, it is possible to realize a photosensitive resin composition that maintains excellent blackness and hiding power and also has excellent resolution, even in the case of forming a thick coating film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Photosensitive resin composition] The photosensitive resin composition according to the present invention comprises, as essential components, (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a colorant, and (D) a photopolymerizable monomer, and is characterized in that the (C) colorant comprises (C1) carbon black, (C2) a perylene-based purple colorant, (C3) a blue colorant, and (C4) a yellow or orange colorant. As described above, when carbon black is used as a black colorant, there is a trade-off between blackness, hiding power, resolution, and deep curing ability. In the present invention, in addition to carbon black, a combination of multiple colored colorants (purple colorant, blue colorant, and yellow or orange colorant) is used to realize a black color, and by using a perylene-based purple colorant as a purple colorant, the resolution is improved while maintaining excellent blackness and hiding power even when a thick coating film is formed. That is, by using a combination of a plurality of colored colorants to produce a black color, and by using a perylene-based purple colorant that has high transmittance for the ultraviolet light (h-line and i-line) used for exposure and low transmittance in a wide range of 450 to 600 nm as the purple colorant, it is believed that the resolution in the deep part is improved even in the case of a thick coating film. Hereinafter, each component constituting the photosensitive resin composition of the present invention will be described.

[0013] <(A) Alkali-soluble resin> The (A) alkali-soluble resin contained in the photosensitive resin composition according to the present invention may be any resin that is alkali-soluble, and known and commonly used resins are used. The alkali-soluble resin may be used alone or in combination of two or more. Examples include water-soluble resins such as carboxyl group-containing resins and phenolic hydroxyl group-containing resins. Among them, carboxyl group-containing resins and phenolic hydroxyl group-containing resins are preferred because of their excellent developability, and carboxyl group-containing resins are more preferred. The alkali-soluble resin can be made alkaline developable by containing a carboxyl group. In addition, from the viewpoint of photosensitivity, it is preferable to have an ethylenically unsaturated double bond in the molecule in addition to the carboxyl group, but only a carboxyl group-containing resin that does not have an ethylenically unsaturated double bond may be used. When the carboxyl group-containing resin does not have an ethylenically unsaturated double bond, it is necessary to use a photopolymerizable monomer in combination to make the composition photocurable. As the ethylenically unsaturated double bond, one derived from acrylic acid or methacrylic acid or a derivative thereof is preferred.

[0014] Specific examples of carboxyl group-containing resins include the following compounds (which may be either oligomers or polymers): In this specification, (meth)acrylate is a general term for acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

[0015] (1) Carboxyl group-containing resins obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth)acrylate, isobutylene, etc.

[0016] (2) Carboxylic acid-containing urethane resins obtained by the polyaddition reaction of diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates with carboxyl-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and diol compounds such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

[0017] (3) Carboxylic acid-containing photosensitive urethane resins obtained by polyaddition reaction of diisocyanates with partially acid anhydride-modified products of reaction products of bifunctional epoxy resins such as bisphenol A type epoxy resins, hydrogenated bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bixylenol type epoxy resins and biphenol type epoxy resins with monocarboxylic acid compounds having ethylenically unsaturated double bonds such as (meth)acrylic acid, carboxyl group-containing dialcohol compounds and diol compounds.

[0018] (4) A photosensitive urethane resin containing a carboxyl group, which is terminated with (meth)acrylation by adding a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule, such as a hydroxyalkyl (meth)acrylate, during the synthesis of the resin (2) or (3).

[0019] (5) A carboxyl group-containing photosensitive urethane resin having a terminal (meth)acrylation formed by adding a compound having one isocyanate group and one or more (meth)acryloyl groups in the molecule, such as an equimolar reactant of isophorone diisocyanate and pentaerythritol triacrylate, during the synthesis of the resin (2) or (3).

[0020] (6) A carboxyl group-containing photosensitive resin obtained by reacting a difunctional or more polyfunctional (solid) epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride to the hydroxyl groups present in the side chains.

[0021] (7) A carboxyl group-containing photosensitive resin obtained by reacting a multifunctional epoxy resin with the hydroxyl groups of a bifunctional (solid) epoxy resin further epoxidized with epichlorohydrin, with (meth)acrylic acid, and then adding a dibasic acid anhydride to the resulting hydroxyl groups.

[0022] (8) Carboxyl group-containing polyester resins obtained by reacting a dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid with a bifunctional oxetane resin and then adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the resulting primary hydroxyl groups.

[0023] (9) A carboxyl group-containing photosensitive resin obtained by reacting an epoxy compound having multiple epoxy groups in one molecule with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol, and an unsaturated group-containing monocarboxylic acid, such as (meth)acrylic acid, and then reacting the alcoholic hydroxyl group of the resulting reaction product with a polybasic acid anhydride, such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid, or the like.

[0024] (10) A carboxyl group-containing photosensitive resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, reacting the reaction product obtained with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride.

[0025] (11) A carboxyl group-containing photosensitive resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, reacting the reaction product obtained with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride.

[0026] (12) A carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups in one molecule to any one of the resins (1) to (11).

[0027] The carboxyl group-containing resins are not limited to those listed above, and may be used alone or in combination. Among the above, the carboxyl group-containing resins synthesized using a compound having a phenolic hydroxyl group as a starting material, such as the carboxyl group-containing resins (10) and (11), are preferably used because of their excellent HAST resistance and PCT resistance.

[0028] The acid value of the carboxyl group-containing resin is preferably 40 to 150 mgKOH / g. By making the acid value of the carboxyl group-containing resin 40 mgKOH / g or more, alkaline development becomes good. Also, by making the acid value 150 mgKOH / g or less, it becomes easy to draw a good resist pattern. More preferably, it is 50 to 130 mgKOH / g.

[0029] The weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, but is generally preferably 2,000 to 150,000. By making the weight average molecular weight 2,000 or more, it is possible to improve tack-free performance and resolution. Furthermore, by making the weight average molecular weight 150,000 or less, it is possible to improve developability and storage stability. It is more preferably 5,000 to 15,000. The weight average molecular weight can be measured by gel permeation chromatography (GPC).

[0030] The amount of the alkali-soluble resin (A) in the photosensitive resin composition is preferably 10 to 50% by mass, calculated as solid content. By making it 10% by mass or more, the coating strength can be improved. Also, by making it 50% by mass or less, the viscosity becomes appropriate and the printability is improved. More preferably, it is 10 to 30% by mass.

[0031] <(B) Photopolymerization initiator>The photosensitive resin composition according to the present invention contains (B) a photopolymerization initiator in order to photopolymerize the above-mentioned (A) carboxyl group-containing resin and (D) a photopolymerizable monomer described below. As the photopolymerization initiator, a known one can be used, for example, an α-aminoacetophenone-based photopolymerization initiator such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, or N,N-dimethylaminoacetophenone; 1-hydroxy-cyclohexylphenylketone; Hydroxyacetophenone photoinitiators such as 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethyl Phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylphenylphosphine oxide, acylphosphine oxide photopolymerization initiators such as methylbenzoyl)-phenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphine acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphine acid isopropyl ester, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide;Benzoin-based photopolymerization initiators such as benzoin, benzil, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ether-based photopolymerization initiators; benzophenone-based photopolymerization initiators such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2-dimethoxy-2-phenylacetophenone acetophenone-based photopolymerization initiators such as 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone; thioxanthone-based photopolymerization initiators such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; anthraquinone, chlorothioxanthone, and chlorothioxanthone; Anthraquinone-based photopolymerization initiators such as chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; ketal-based photopolymerization initiators such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid ester-based photopolymerization initiators such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, and p-dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1-[4-(phenyl)anthraquinone ... oxime ester photoinitiators such as ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime); bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyrrol-1-yl)ethyl)phenyl]titanium;These photopolymerization initiators may be used alone or in combination of two or more.

[0032] Among the above-mentioned photopolymerization initiators, titanocene-based photopolymerization initiators can be preferably used from the viewpoint of realizing better resolution while maintaining blackness and hiding power. (C2) Perylene-based purple colorant has high transmittance in the ultraviolet region as described above, and titanocene-based initiator is a photopolymerization initiator that has a wide absorption range beyond the ultraviolet region. It is considered that by using such a colorant in combination with a titanocene-based initiator, deep curing properties are improved and a cured product with excellent resolution can be obtained. As the titanocene-based photopolymerization initiator, any known photopolymerization initiator that has a titanocene structure and is photosensitive to light absorption wavelengths of 400 to 700 nm can be used. Specific examples of titanocene-based photopolymerization initiators include bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr-1-yl)ethyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(3-(1-pyr-1-yl)propyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((1-pyr-1-yl)methyl)phenyl]titanium, bis(methylcyclopentadienyl)-bis[2,6-difluoro-3-((1-pyr-1-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2,5-dimethyl-1-pyr-1-yl)methyl)phenyl]titanium, and bis(cyclopentadienyl). bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2-isopropyl-5-methyl-1-pyr-1,6-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2-(2-methoxyethyl)-5-methyl-1-pyr-1-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((3-trimethylsilyl-2,5-dimethyl-1-pyr-1-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2,5-dimethyl-3-(bis(2-methoxyethyl)aminomethyl)-1-pyr-1-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2,5-Bis(morpholinomethyl)-1-pyr-1-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2,5-dimethyl-3-(1,3-dioxolan-2-yl)-1-pyr-1-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-4-((2,5-dimethyl-1-pyr-1-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-methyl-4-(2-(1-pyr-1-yl)methyl)phenyl]titanium )ethyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2,3,4,5-tetramethyl-1-pyr-1-yl)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,3,5,6-tetrafluoro-4-(3-(1-pyr-1-yl)propyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr-1-yl)propyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro- 3-(1-methyl-2-(1-pyr-1-yl)ethyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(3-(2-isoindol-2-yl)propyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(4,5,6,7-tetrahydro-isoindol-2-yl)ethyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(6-(9-carbazol-9-yl)hexyl)phenyl]titanium, bis (Cyclopentadienyl)-bis[2,6-difluoro-3-(3-(2,3,4,5,6,7,8,9-octahydro-1-carbazol-9-yl)propyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(3-(4,5,6,7-tetrahydro-2-methyl-1-indol-1-yl)propyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-((acetylamino)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(propionylamino)ethyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(3-(acetylamino)propyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(4-(pivaloylamino)butyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(2,2-dimethylpentanoylamino)ethyl)phenyl]titanium, bis(cyclopentadiene bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2,2-dimethylpentanoylamino)methyl)phenyl]titanium; bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(2,2-dimethyl-3-chloropropanoylamino)ethyl)phenyl]titanium; bis(cyclopentadienyl)-bis[2,6-difluoro-3-((2,2-dimethyl-3-ethoxy propanoylamino)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(lauroylamino)ethyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(N-allylmethylsulfonylamino)ethyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(3-(N-isobutylphenylsulfonylamino)propyl)phenyl]titanium, bis(cyclopentadienyl) -Bis[2,6-difluoro-3-((methylsulfonylamino)methyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(3-(ethylsulfonylamino)propyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(butylsulfonylamino)ethyl)phenyl]titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(4-(trisulfonylamino)propyl)phenyl]titanium, bis(η, 5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium. These titanocene photopolymerization initiators can be used alone or in combination of two or more. Commercially available products include JMT-784 manufactured by Yueyang Kimoutain Sci-tech Co., Ltd.

[0033] The titanocene-based photopolymerization initiator is preferably used in combination with the above-mentioned α-aminoacetophenone-based photopolymerization initiator.

[0034] The amount of the photopolymerization initiator (B) in the photosensitive resin composition is preferably 1 to 50 parts by mass, more preferably 1 to 20 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content, which can improve the curability in deep areas.

[0035] In addition to the above-mentioned photopolymerization initiators, benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthone compounds can be used as photopolymerization initiators. Two or more of the above-mentioned compounds may be used in combination. It is preferable to use the photopolymerization initiators exemplified here as photopolymerization initiator assistants or sensitizers in combination with the above-mentioned photopolymerization initiators, rather than using them alone as photopolymerization initiators.

[0036] When the photosensitive resin composition contains the benzoin compound or the like as a photopolymerization initiator, the amount of the benzoin compound or the like is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content, which can improve the curability of the deeper portion.

[0037] <(C) Colorant> The photosensitive resin composition according to the present invention contains, as the colorant (C), (C1) carbon black, (C2) a perylene-based purple colorant, (C3) a blue colorant, and (C4) a yellow or orange colorant.

[0038] Examples of (C1) carbon black include channel black, oil furnace black, gas furnace black, thermal black, acetylene black, and bone black. Among these, from the viewpoint of insulation, it is desirable to use carbon black with an underdeveloped graphite structure and a large electrical resistance. Commercially available carbon blacks may be used, such as MA-100, MA-100R, MA-600, #25, #3230, and 33250 (all manufactured by Mitsubishi Chemical Corporation), REGAL99R (manufactured by Cabot Corporation), Raven860U, and Raven780ULTRA (all manufactured by Columbian Chemicals), Prix 25 (manufactured by Degussa), and HTC#100 (manufactured by Nippon Steel Chemical & Material Co., Ltd.).

[0039] From the viewpoints of blackness and hiding power, the (C1) carbon black is contained in an amount of preferably 0.01 to 0.2% by mass, and more preferably 0.03 to 0.1% by mass, based on the total mass of the (C) colorant.

[0040] As the perylene-based purple colorant (C2), one having a broad absorption maximum in the range of 500 to 600 nm can be preferably used, and an example thereof is Paliogen Red Violet K 5411 (CI Pigment Violet 29, manufactured by BASF Japan Ltd.).

[0041] From the viewpoints of hiding power and resolution, the perylene purple colorant (C2) is contained in an amount of preferably 20 to 50% by mass, and more preferably 30 to 40% by mass, based on the total amount of the perylene purple colorant (C2), the blue colorant (C3), and the yellow or orange colorant (C4).

[0042] (C3) Blue colorants include phthalocyanine and anthraquinone types, and pigment types include compounds classified as pigments, such as Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, and 60. Dye types include Solvent Blue 35, 63, 67, 68, 70, 83, 87, 94, 97, 122, and 136. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used. Among these blue colorants, for example, Pigment Blue 15:4 can be preferably used.

[0043] From the viewpoint of opacifying light in the visible light region (particularly, the wavelength region of 550 nm to 750 nm), the blue colorant (C3) is preferably contained in an amount of 15 to 60% by mass, and more preferably 25 to 40%, based on the total amount of the perylene purple colorant (C2), the blue colorant (C3), and the yellow or orange colorant (C4).

[0044] Examples of the yellow colorant (C4) include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone. For example, anthraquinone yellow colorants include Solvent Yellow 163, Pigment Yellow 24, 108, 193, 147, 199, and 202. Examples of isoindolinone yellow colorants include Pigment Yellow 110, 109, 139, 179, and 185. Examples of condensed azo yellow colorants include Pigment Yellow 93, 94, 95, 128, 155, 166, and 180. Examples of benzimidazolone yellow colorants include Pigment Yellow 120, 151, 154, 156, 175, and 181. Examples of monoazo yellow colorants include Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62:1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, and 183. Examples of disazo yellow colorants include Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, and 198. Among these yellow colorants, Pigment Yellow 149 can be preferably used. Examples of the orange colorant (C4) include Pigment Orange 1, 5, 13, 14, 16, 17, 24, 34, 36, 38, 40, 43, 46, 49, 51, 63, 64, 71, and 73. Among these orange colorants, Pigment Orange 71 can be preferably used.

[0045] From the viewpoints of blackness and hiding power, the yellow or orange colorant (C3) is contained in an amount of preferably 10 to 30% by mass, and more preferably 15 to 25% by mass, based on the total amount of the perylene purple colorant (C2), the blue colorant (C3), and the yellow or orange colorant (C4).

[0046] From the viewpoint of achieving a balance between blackness, hiding power, and resolution, the ratio of the total content of the colorants (C2), (C3), and (C4) as the colorant (C) to the content of the carbon black (C1) is preferably within a range of 20:1 to 80:1, and more preferably within a range of 40:1 to 60:1.

[0047] From the viewpoint of achieving a balance between blackness, hiding power, and resolution, the colorant (C) is preferably contained in an amount of 1 to 2.5 mass % and more preferably 1.5 to 2 mass % based on the total solid content of the photosensitive resin composition.

[0048] <(D) Photopolymerizable monomer> The photosensitive resin composition of the present invention contains (D) a photopolymerizable monomer. The photopolymerizable monomer is a monomer having an ethylenically unsaturated double bond. Examples of such photopolymerizable monomers include commonly known polyester (meth)acrylates, polyether (meth)acrylates, urethane (meth)acrylates, carbonate (meth)acrylates, and epoxy (meth)acrylates. Specifically, alkyl acrylates such as 2-ethylhexyl acrylate and cyclohexyl acrylate; hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; mono- or diacrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; acrylamides such as N,N-dimethylacrylamide, N-methylolacrylamide, and N,N-dimethylaminopropylacrylamide; aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, and trishydroxyethyl isocyanurate. Polyhydric alcohols such as polyhydric alcohols or their alkylene oxide adducts or ε-caprolactone adducts; phenols such as phenoxy acrylate and bisphenol A diacrylate or their alkylene oxide adducts; glycidyl ether acrylates such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and acrylates obtained by directly acrylate or urethane acrylate of polyols such as polyether polyols, polycarbonate diols, hydroxyl group-terminated polybutadiene, and polyester polyols, as well as melamine acrylates and at least one of the methacrylates corresponding to the acrylates, can be appropriately selected and used. Such photopolymerizable monomers can also be used as reactive diluents.

[0049] The (D) photopolymerizable monomer may be used alone or in combination of two or more. The amount of the photopolymerizable monomer is preferably 0.5 to 30 parts by mass, calculated as solid content, per 100 parts by mass of the (A) alkali-soluble resin. When the amount is 0.5 parts by mass or more, the photocurability is good, and pattern formation is easy in alkaline development after irradiation with active energy rays. When the amount is 30 parts by mass or less, halation is unlikely to occur and good resolution can be obtained.

[0050] <Thermosetting component> The photosensitive resin composition of the present invention may contain a thermosetting component as an optional component in addition to the above-mentioned components. Examples of the thermosetting component include known and commonly used ones such as isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, oxetane compounds, and episulfide resins. Among these, the preferred thermosetting component is an epoxy resin.

[0051] Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, hydrogenated bisphenol A type epoxy resins, brominated bisphenol A type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, biphenyl type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, triphenylmethane type epoxy resins, and the like. These may be used alone or in combination of two or more.

[0052] Examples of commercially available epoxy resins include jER 828, 806, 807, YX8000, YX8034, and 834 manufactured by Mitsubishi Chemical Corporation; YD-128, YDF-170, ZX-1059, and ST-3000 manufactured by Nippon Steel Chemical & Material Co., Ltd.; EPICLON 830, 835, 840, 850, N-730A, and N-695 manufactured by DIC Corporation; and RE-306 manufactured by Nippon Kayaku Co., Ltd.

[0053] The equivalent weight of the epoxy group of the epoxy resin in the photosensitive resin composition is preferably 0.5 to 2.5 in terms of solid content relative to the equivalent weight of the carboxyl group of the carboxyl group-containing resin (1). By making it 0.5 equivalent weight or more, it is possible to prevent the carboxyl group from remaining in the cured product, and to obtain good heat resistance, alkali resistance, electrical insulation, etc. Also, by making the blending amount 2.5 equivalent weight or less, it is possible to prevent the low molecular weight cyclic (thio)ether group from remaining in the dried coating film, and to ensure good strength of the cured product, etc.

[0054] When the photosensitive resin composition of the present invention contains a thermosetting component, it may contain a thermosetting catalyst for promoting the curing of the thermosetting component. Examples of the thermosetting catalyst include imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, and 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Other commercially available compounds include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, and 2P4MHZ (all trade names of imidazole-based compounds) manufactured by Shikoku Chemical Industry Co., Ltd., and U-CAT 3513N (trade name of dimethylamine-based compound), DBU, DBN, and U-CAT SA 102 (all bicyclic amidine compounds and salts thereof) manufactured by San-Apro Co., Ltd.

[0055] The compounds are not limited to the above, and may be used alone or in combination of two or more as long as they are heat curing catalysts for epoxy resins or oxetane compounds, or catalysts that promote the reaction of at least one of epoxy groups and oxetanyl groups with carboxyl groups. In addition, S-triazine derivatives such as guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine·isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine·isocyanuric acid adduct may also be used, and preferably, these compounds that also function as adhesion promoters are used in combination with the heat curing catalyst.

[0056] The thermosetting catalyst may be used alone or in combination of two or more. From the viewpoint of the storage stability of the resin composition and the heat resistance of the cured coating, the amount of the thermosetting catalyst is preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass, calculated as solid content per 100 parts by mass of the alkali-soluble resin (A).

[0057] <Other ingredients> The photosensitive resin composition according to the present invention can be blended with a filler as necessary in order to improve the physical strength of the cured product obtained or to adjust the matte feel of the surface. As the filler, known inorganic or organic fillers can be used, and barium sulfate, spherical silica, hydrotalcite, and talc are particularly preferably used. In addition, metal oxides and metal hydroxides such as aluminum hydroxide can be used as extender pigment fillers to obtain flame retardancy.

[0058] The amount of the filler to be blended is not particularly limited, but from the viewpoints of viscosity, coatability, moldability, etc., the amount is preferably 300 parts by mass or less, more preferably 50 to 200 parts by mass, per 100 parts by mass of the alkali-soluble resin, calculated as solid content.

[0059] The above-mentioned filler may be surface-treated to enhance dispersibility in the photosensitive resin composition. By using a surface-treated filler, aggregation can be suppressed. The surface treatment method is not particularly limited, and a known and commonly used method may be used, but it is preferable to treat the surface of the inorganic filler with a surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group.

[0060] As the coupling agent, silane-based, titanate-based, aluminate-based, zircoaluminate-based, and other coupling agents can be used. Among them, silane-based coupling agents are preferred. Examples of such silane-based coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N-(2-aminomethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane, which can be used alone or in combination. It is preferable that these silane-based coupling agents are immobilized on the surface of the filler in advance by adsorption or reaction. Here, the amount of the coupling agent to be treated with respect to 100 parts by mass of the spherical silica is preferably 0.5 to 10 parts by mass.

[0061] In addition to the above-mentioned colorants, the photosensitive resin composition according to the present invention may contain other colorants as necessary. As the colorant, a known colorant such as red, green, or yellow can be used, and any of a pigment, dye, and coloring matter can be used, but from the viewpoint of reducing the environmental load and having little effect on the human body, a colorant that does not contain halogen is preferable.

[0062] The photosensitive resin composition may contain an organic solvent from the viewpoint of ease of preparation and coatability when forming a resin layer. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha. Known and commonly used organic solvents can be used. These organic solvents can be used alone or in combination of two or more.

[0063] The amount of the organic solvent in the photosensitive resin composition can be appropriately changed depending on the materials constituting the photosensitive resin composition, and can be, for example, 30 to 300 parts by mass, calculated as solid content, per 100 parts by mass of the alkali-soluble resin.

[0064] The photosensitive resin composition may further contain, as necessary, components such as elastomers, mercapto compounds, urethanization catalysts, thixotropic agents, adhesion promoters, block copolymers, chain transfer agents, polymerization inhibitors, copper inhibitors, antioxidants, rust inhibitors, thickeners such as organic bentonite and montmorillonite, at least one of silicone-based, fluorine-based, and polymer-based defoamers and leveling agents, and flame retardants such as phosphorus compounds such as phosphinates, phosphate ester derivatives, and phosphazene compounds. These may be known in the field of electronic materials.

[0065] <Dry film> The photosensitive resin composition of the present invention can also be in the form of a dry film comprising a first film and a resin layer made of the photosensitive resin composition formed on the first film. The first film in the dry film according to the present invention refers to a film that is at least adhered to the resin layer when the film is laminated by heating or the like onto a substrate such as a board so that the resin layer made of the photosensitive resin composition formed on the dry film is in contact with the substrate and integrally molded. The first film may be peeled off from the resin layer in a step after lamination. In particular, in the present invention, it is preferable to peel off from the resin layer in a step after exposure.

[0066] To prepare a dry film, the photosensitive resin composition of the present invention is diluted with an organic solvent to adjust the viscosity to an appropriate level, and then coated onto a first film in a uniform thickness using a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, spray coater, or the like, and typically dried for 1 to 30 minutes at a temperature of 50 to 130° C. to obtain a film. There are no particular limitations on the coating film thickness, but it is generally appropriately selected within the range of 1 to 150 μm, preferably 10 to 60 μm, in terms of the film thickness after drying.

[0067] As the first film, any known film can be used without any particular limitation, and for example, a film made of a thermoplastic resin such as a polyester film such as polyethylene terephthalate or polyethylene naphthalate, a polyimide film, a polyamideimide film, a polypropylene film, or a polystyrene film can be suitably used. Among these, a polyester film is preferred from the viewpoints of heat resistance, mechanical strength, handling, etc. A laminate of these films can also be used as the first film.

[0068] From the viewpoint of improving mechanical strength, the above-mentioned thermoplastic resin film is preferably a film stretched in a uniaxial or biaxial direction.

[0069] The thickness of the first film is not particularly limited, but can be, for example, 10 μm to 150 μm.

[0070] After forming a resin layer of the photosensitive resin composition of the present invention on the first film, it is preferable to further laminate a peelable second film on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer, etc. The second film in the dry film of the present invention refers to a film that is peeled off from the resin layer before lamination when the dry film is laminated by heating or the like so that the resin layer side of the dry film is in contact with a base material such as a substrate to be integrally molded.

[0071] The second film that can be peeled off from the resin layer may be, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, surface-treated paper, etc., as long as the adhesive strength between the resin layer and the second film is smaller than the adhesive strength between the resin layer and the first film when the second film is peeled off.

[0072] The thickness of the second film is not particularly limited, but can be, for example, 10 μm to 150 μm.

[0073] <Cured product> The cured product of the present invention is obtained by curing the above-mentioned photosensitive resin composition or the resin layer of the above-mentioned dry film.

[0074] <Printed wiring board> The printed wiring board of the present invention has a cured product obtained from the resin layer of the photosensitive resin composition or dry film of the present invention. As a method for producing the printed wiring board of the present invention, for example, the photosensitive resin composition of the present invention is adjusted to a viscosity suitable for the coating method using the organic solvent, and applied to a substrate by a method such as dip coating, flow coating, roll coating, bar coating, screen printing, or curtain coating, and then the organic solvent contained in the composition is evaporated and dried (temporarily dried) at a temperature of 60 to 100 ° C. to form a tack-free resin layer. In addition, in the case of a dry film, the resin layer is attached to the substrate by a laminator or the like so that the resin layer contacts the substrate, and then the first film is peeled off to form a resin layer on the substrate.

[0075] The above-mentioned substrates include printed wiring boards and flexible printed wiring boards with circuits formed in advance using copper or the like, as well as materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, copper-clad laminates for high-frequency circuits using materials such as fluororesin-polyethylene-polyphenylene ether, polyphenylene oxide-cyanate, etc., including copper-clad laminates of all grades (FR-4, etc.), as well as metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates, etc.

[0076] In the case of a dry film form, the lamination onto the substrate is preferably performed under pressure and heat using a vacuum laminator or the like. By using such a vacuum laminator, when a circuit-formed substrate is used, even if the surface of the circuit substrate is uneven, the dry film adheres to the circuit substrate, so that no air bubbles are mixed in, and the filling of the recesses on the substrate surface is improved. The pressure condition is preferably about 0.1 to 2.0 MPa, and the heating condition is preferably 40 to 120°C.

[0077] When the photosensitive resin composition of the present invention contains an organic solvent, it is preferable to apply the photosensitive resin composition to the surface of a substrate and then perform volatilization drying. The volatilization drying can be performed using a hot air circulation drying oven, an IR oven, a hot plate, a convection oven, etc. (a method of countercurrent contact of hot air in a dryer using a heat source of an air heating method using steam, or a method of spraying the hot air from a nozzle onto the substrate).

[0078] After forming a resin layer on a substrate, the resin layer is selectively exposed to active energy rays through a photomask having a predetermined pattern formed thereon, and the unexposed portion is developed with a dilute alkaline aqueous solution (e.g., 0.3 to 3 mass% aqueous sodium carbonate solution) to form a pattern of the cured product. In the case of a dry film, after exposure, the first film is peeled off from the dry film and development is performed to form a patterned cured product on the substrate. In addition, in the case of a dry film form, the first film may be peeled off from the dry film before exposure, and the exposed resin layer may be exposed and developed, as long as the characteristics are not impaired. Furthermore, a cured coating excellent in various properties such as adhesion and hardness can be formed by irradiating the cured product with active energy rays and then heat curing (e.g., 100 to 220°C), or irradiating active energy rays after heat curing, or by heat curing only to perform final finish curing (main curing).

[0079] The exposure machine used for the above-mentioned active energy ray irradiation may be a machine equipped with a high pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like, and capable of irradiating ultraviolet rays in the range of 350 to 450 nm. Furthermore, a direct imaging machine (for example, a laser direct imaging machine that directly draws an image with a laser based on CAD data from a computer) may also be used. The lamp light source or laser light source of the direct imaging machine may have a maximum wavelength in the range of 350 to 450 nm. The exposure dose for forming an image varies depending on the film thickness, etc., but is generally 10 to 1000 mJ / cm. 2 , preferably 20 to 800 mJ / cm 2 The range may be:

[0080] The developing method can be a dipping method, a shower method, a spray method, a brush method, or the like, and the developing solution can be an aqueous alkali solution of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, or the like.

[0081] After the cured coating is formed on the substrate as described above, components such as electronic elements are mounted on the substrate by solder reflow treatment. The solder reflow treatment can be performed by a conventionally known method. In general, the solder reflow treatment is performed under treatment conditions of, for example, 245 to 260°C for 5 to 10 seconds.

[0082] The photosensitive resin composition or dry film of the present invention is preferably used for manufacturing electronic parts such as printed wiring boards, and more preferably used to form a permanent coating. In this case, the photosensitive resin composition or dry film of the present invention is used to form a cured product by the above-mentioned method or the like. When the resin layer of the photosensitive resin composition or dry film of the present invention is insulating, it is preferably used to form a solder resist, a coverlay, or an interlayer insulating layer. EXAMPLES

[0083] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following, "parts" and "%" are all based on mass unless otherwise specified.

[0084] <Synthesis example: Synthesis of alkali-soluble resin> To 650 parts by mass of diethylene glycol monoethyl ether acetate, 1,070 g of orthocresol novolac epoxy resin (EPICLON N-695, manufactured by DIC Corporation, softening point 95°C, epoxy equivalent 214, average functionality 7.6), 360 g of acrylic acid, and 1.5 g of hydroquinone were charged, and the mixture was heated to 100°C with stirring to dissolve uniformly. Next, 4.3 parts by mass of triphenylphosphine was added, heated to 110° C. and reacted for 2 hours, after which 1.6 parts by mass of triphenylphosphine was further added, the temperature was raised to 120° C. and the reaction was further carried out for 12 hours. To the resulting reaction solution, 525 g of aromatic hydrocarbon (T-Sol 150, manufactured by Standard Oil Co., Ltd. Osaka Sales Office) and 608 g (4.0 mol) of tetrahydrophthalic anhydride were added, and the reaction was carried out for 4 hours at 110° C. Furthermore, 142.0 g of glycidyl methacrylate was added to the resulting reaction solution, and the reaction was carried out for 4 hours at 115° C. In this way, a solution of an alkali-soluble resin having a solid content of 65% and an acid value of the solid content of 77 mgKOH / g was obtained.

[0085] <Preparation of Photosensitive Resin Composition> The components shown in Table 1 below were mixed and mixed at room temperature using a three-roll mill to obtain the photosensitive resin compositions shown in the table. Each value in the table indicates parts by mass (mass including the solvent).

[0086] In addition, each component *1 to *18 in Table 1 below is as follows. *1: Alkali-soluble resin synthesized above (solid content 65%) *2: α-aminoacetophenone photopolymerization initiator (manufactured by IGM Resins) *3: Titanocene photopolymerization initiator (manufactured by Yueyang Kimoutain Sci-tech Co., Ltd.) *4: Oxime ester photopolymerization initiator (manufactured by BASF Japan Ltd.) *5: Carbon black (manufactured by Mitsubishi Chemical Corporation) *6: Perylene-based purple colorant (manufactured by BASF Japan Ltd.) *7: Quinacridone red colorant (manufactured by Sun Chemical Co., Ltd.) *8: Phthalocyanine blue colorant (manufactured by DIC Corporation) *9: Benzimidazolone-dioxazine blue colorant *10: Anthraquinone yellow colorant (manufactured by BASF Japan Ltd.) *11: Diketopyrrolopyrrole orange colorant (manufactured by Sun Chemical Co., Ltd.) *12: Dipentaerythritol polyacrylate (manufactured by Shin-Nakamura Industrial Chemical Co., Ltd.) *13: Epoxy resin (manufactured by Nissan Chemical Co., Ltd.) *14:Dicyandiamide *15: Barium sulfate (Sakai Chemical Industry Co., Ltd.) *16: Talc (manufactured by Fuji Talc Industry Co., Ltd.) *17: Oil compound type defoamer (manufactured by Shin-Etsu Silicone Co., Ltd.) *18: Polymer-based defoamer (manufactured by BYK)

[0087] <Evaluation of resolution> A circuit pattern substrate with a copper thickness of 50 μm was prepared, and as a pretreatment, a copper surface roughening treatment (MEC Etch Bond (TM) CZ-8101B, manufactured by MEC Co., Ltd.) was performed, and the substrate surface was etched to a depth of 1.0 μm. Next, each of the photosensitive resin compositions obtained as described above was applied to the entire surface of the substrate by screen printing so that the film thickness after drying was 40 μm, and then dried for 30 minutes in a hot air circulation drying oven at 80° C. After drying, the coating was exposed using a high-pressure mercury lamp exposure device. The exposure pattern used was a pattern that drew 100 μm lines in the space areas. The exposure dose was 75 mJ / cm 2 After irradiating the film with light using an exposure device so that the film was exposed to light, the film was developed with an aqueous solution of sodium carbonate (30°C, 0.2 MPa, 1 wt% aqueous solution of sodium carbonate) to form a pattern. The film was then thermally cured at 150°C for 60 minutes to obtain a cured coating film. The cross section of the board in the line direction and the direction perpendicular to the line direction was observed by SEM, and the solder dam was evaluated according to the following evaluation criteria. ○: The absolute value of the line width above the solder dam minus the line width below the solder dam is 20 μm or less △: The absolute value of the line width above the solder dam minus the line width below the solder dam is 20 to 30 μm. ×: The absolute value of the line width above the solder dam minus the line width below the solder dam exceeds 40 μm The evaluation results are shown in Table 1 below.

[0088] <Evaluation of Concealment> A copper solid substrate with a copper thickness of 18 μm was pretreated with CZ treatment (roughening treatment) at an etching rate of 1 μm using CZ-8101B manufactured by MEC Co., Ltd. Each photosensitive resin composition was applied to a thickness of 10 μm and 20 μm, and dried at 80° C. for 10 minutes. Next, the resin layer was exposed to light using an exposure device equipped with a high-pressure mercury lamp (short arc lamp), and developed with a 1% by mass aqueous solution of sodium carbonate at 30°C for 60 seconds under conditions of a spray pressure of 0.2 MPa. The obtained substrate was then exposed to light in a UV conveyor furnace with an integrated exposure dose of 1000 mJ / cm. 2 After irradiating with ultraviolet light under the above conditions, the resin layer was cured by heating at 150° C. for 60 minutes to obtain an evaluation substrate.

[0089] For the evaluation boards with film thicknesses of 10 μm and 20 μm obtained as described above, a spectrophotometer (CM-2600d, manufactured by Konica Minolta, Inc.) was used to measure the a* and b* of the L*a*b* color system under conditions including total reflected light in accordance with JIS Z 8729. The absolute values ​​Δa* and Δb* were calculated by subtracting the a* and b* values ​​of the 10 μm thick solder resist layer on the copper foil from the a* and b* values ​​of the 20 μm thick solder resist layer on the copper foil, and the degree of influence of the color of the underlying copper and the hiding power when the solder resist layer was made thinner were evaluated according to the following criteria. ○: Both Δa* and Δb* values ​​are 1.0 or less △: Either Δa* or Δb* is 1.0 or less ×: Both Δa* and Δb* values ​​are 1.0 or more The evaluation results are shown in Table 1 below.

[0090] <Evaluation of Blackness> A printed wiring board was prepared by subjecting the copper foil surface of a full copper foil substrate, which had a copper foil of 35 μm thickness laminated on the entire surface, to CZ treatment (roughening treatment) at an etching rate of 1 μm using CZ-8101B manufactured by MEC Co., Ltd. Each of the photosensitive resin compositions obtained as described above was applied to the copper foil surface of the printed wiring board, the surface of which had been CZ-treated, using an applicator, and dried at 80° C. for 10 minutes to form a resin layer. Next, the resin layer was exposed to light using an exposure device equipped with a high-pressure mercury lamp (short arc lamp), and developed with a 1% by mass aqueous solution of sodium carbonate at 30°C for 60 seconds under conditions of a spray pressure of 0.2 MPa. The obtained substrate was then exposed to light in a UV conveyor furnace with an integrated exposure dose of 1000 mJ / cm. 2 After irradiating with ultraviolet light under the above conditions, the resin layer was cured by heating at 150° C. for 60 minutes, thereby producing a substrate in which a 10 μm-thick cured product was formed on the copper foil. Next, the surface of the cured product of the substrate obtained as described above was measured for a* and b* in the L*a*b* color system using a spectrophotometer (CM-2600d, manufactured by Konica Minolta) under conditions including total reflected light in accordance with JIS Z 8729.

[0091] From the obtained a* and b*, the blackness was evaluated according to the following evaluation criteria. ◯: a value is -5 to 5 and b value is -5 to 5 △: a value is -10 to -5 or 5 to 10, and b value is -10 to -5 or 5 to 10 ×: a value is <-10 or >10 and b value is <-10 or >10 The results are shown in Table 1.

[0092] [Table 1]

[0093] As is clear from the results in Table 1, when a photosensitive resin composition (Comparative Example 1) containing a purple pigment having a quinacridone skeleton with weak absorption around 450 to 600 nm as a colorant is cured, the Δa* value and Δb* value become larger than 1.0 when the film thickness is changed from 10 μm to 20 μm, and it is found that the hiding power is insufficient. In contrast, when a photosensitive resin composition (Examples 1 to 4) containing a perylene-based purple pigment as a colorant with strong absorption from 450 to 600 μm is cured, the Δa* value and / or Δb* value are 1.0 or less when the film thickness is changed from 10 μm to 20 μm, and it is found that the hiding power is improved and the L*a*b* value does not change even when the film thickness is changed. Furthermore, as is clear from a comparison between Examples 1 and 4, it can be seen that the resolution is improved by combining a titanocene initiator as a photopolymerization initiator. This is believed to be due to the fact that the titanocene initiator has a wide absorption range extending beyond the ultraviolet region and has excellent deep curing properties, and the perylene purple colorant has high transmittance in the ultraviolet region.

Claims

1. A photosensitive resin composition comprising at least (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a colorant, and (D) a photopolymerizable monomer, The colorant (C) is (C1) carbon black, (C2) a perylene-based purple colorant; (C3) a blue colorant; and (C4) a yellow or orange colorant; A photosensitive resin composition comprising:

2. The photosensitive resin composition according to claim 1 , wherein the blue colorant (C3) comprises a pigment having a phthalocyanine skeleton.

3. 2. The photosensitive resin composition according to claim 1, wherein the yellow or orange colorant (C4) comprises a pigment having a skeleton selected from the group consisting of an anthraquinone skeleton and a diketopyrrolopyrrole skeleton.

4. The photosensitive resin composition according to claim 1 , wherein the photopolymerization initiator (B) comprises a titanocene-based photopolymerization initiator.

5. 2. The photosensitive resin composition according to claim 1, wherein a ratio of a total content of the colorants (C2), (C3), and (C4) to a content of the carbon black (C1) is 20:1 to 80:1 on a mass basis.

6. 2. The photosensitive resin composition according to claim 1, wherein the colorant (C) is contained in an amount of 1 to 4 mass % based on the total solid content of the photosensitive resin composition.

7. A dry film comprising: a first film; and a resin layer formed by applying the photosensitive resin composition according to claim 1 to one surface of the first film and drying the composition.

8. A cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 6 or the resin layer of the dry film according to claim 7.

9. A printed wiring board provided with a coating comprising the cured product according to claim 8.

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