TWI815304B - Photosensitive resin composition, dry film, solder resist, and printed wiring board - Google Patents

Abstract

The present invention provides a photosensitive resin composition that can improve developability and deep hardenability even if it contains titanium oxide, and can improve the appearance and reflectivity of a solder resist layer. The photosensitive resin composition contains carboxyl group-containing resin (A), photopolymerization initiator (B), photopolymerizable compound (C), epoxy resin (D), and titanium oxide (E). The carboxyl group-containing resin (A) has a carboxyl group-containing residue and an ethylenically unsaturated group located in a side chain, and contains a vinyl polymer with a weight average molecular weight of 10,000 or more and 100,000 or less, and the carboxyl group-containing resin (A) contains a vinyl polymer with a molecular weight of 450 The oligomer fraction above and below 1000. The proportion of titanium oxide (E) is 20 parts by mass or more relative to 100 parts by mass of the carboxyl group-containing resin (A).

Description

Photosensitive resin compositions, dry films, solder resists and printed circuit boards

The present invention relates to a photosensitive resin composition, dry film, solder resist and printed circuit board. Specifically, the invention relates to: a photosensitive resin composition, which contains a carboxyl-containing resin, a photopolymerization initiator, a photopolymerization photosensitive compounds, epoxy resins and titanium oxide; and dry films, solder resists and printed circuit boards using the photosensitive resin composition.

When manufacturing printed circuit boards in electronic equipment and the like, the photosensitive resin composition used to form a solder resist layer and the like should not only have excellent developability, that is, the time required for development, that is, the break point, but also be short. It has a wide drying range and can set the drying time of the coating film to be longer. In this photosensitive resin composition, in order to more effectively reflect the light emitted from the optical elements of electronic equipment such as the backlight of a liquid crystal display, a carboxyl-containing resin, a photopolymerization initiator, and a photopolymerization agent are added to the solder resist layer. In addition to the chemical compound and epoxy resin, it also contains titanium oxide to whiten the solder resist layer (see Patent Document 1 (Japanese Laid-Open Patent Publication No. 2018-36574), Patent Document 2 (International Publication No. 2016/052653) and Patent document 3 (Japanese Patent Publication No. 2020-70436)).

When the photosensitive resin composition contains titanium oxide in this manner, when the photosensitive resin composition is cured by exposure, the titanium oxide reflects or absorbs light, making it difficult to cure and reducing developability. In addition, when the titanium oxide content is high, it becomes difficult to harden the formed solder resist layer from the surface layer part to the deep part, and the deep hardenability is reduced. Furthermore, due to the difference in hardening shrinkage between the deep part and the surface part of the solder resist layer, lines will be generated on the solder resist layer, and the gloss will be reduced and the appearance will become poor, and the reflectivity of the solder resist layer will also be reduced. The above-mentioned conventional compositions containing titanium oxide have the above-mentioned defects.

[Technical problem to be solved by the invention] The problem to be solved by the present invention is to provide: a photosensitive resin composition that can improve developability and deep hardenability even if it contains titanium oxide, and can improve the appearance and reflectivity of the solder resist layer; and, using Dry film, solder resist and printed circuit board of the photosensitive resin composition.

One aspect of the photosensitive resin composition of the present invention contains: carboxyl-containing resin (A), photopolymerization initiator (B), photopolymerizable compound (C), epoxy resin (D), and titanium oxide (E) . The aforementioned carboxyl group-containing resin (A) has a carboxyl group-containing residue and an ethylenically unsaturated group located in a side chain, and contains a vinyl polymer with a weight average molecular weight of 10,000 or more and 100,000 or less, and the aforementioned carboxyl group-containing resin (A) contains a molecular weight It is the oligomer part of 450 or more and 1000 or less. The proportion of the titanium oxide (E) is 20 parts by mass or more relative to 100 parts by mass of the carboxyl group-containing resin (A).

A dry film according to one aspect of the present invention contains the aforementioned photosensitive resin composition.

A solder resist according to one aspect of the present invention contains a cured product of the photosensitive resin composition.

A printed circuit board according to one aspect of the present invention is provided with a solder resist layer, and the solder resist layer contains a cured product of the aforementioned photosensitive resin composition.

〈Photosensitive resin composition〉 The photosensitive resin composition (hereinafter, also referred to as composition (X)) of this embodiment contains: a carboxyl group-containing resin (A) (hereinafter, also referred to as resin (A)), a photopolymerization initiator (B), Photopolymerizable compound (C), epoxy resin (D) and titanium oxide (E). The resin (A) has a carboxyl-containing residue and an ethylenically unsaturated group located in the side chain, and contains a vinyl polymer with a weight average molecular weight of 10,000 or more and 100,000 or less, and the resin (A) contains a vinyl polymer with a molecular weight of 450 or more and 1,000 or less. oligomer part. The proportion of titanium oxide (E) is 20 parts by mass or more relative to 100 parts by mass of the resin (A).

In order to solve the problems to be solved by the present invention, the inventor devoted himself to research on a photosensitive resin composition containing a carboxyl-containing resin, a photopolymerization initiator, a photopolymerizable compound, an epoxy resin and titanium oxide. As a result, it was discovered that when a resin (A) having a carboxyl group-containing residue and an ethylenically unsaturated group located in a side chain is used as the carboxyl group-containing resin, and the resin (A) has a weight average molecular weight in a specific range and When the resin (A) has an oligomer part with a molecular weight in a specific range, it can improve the developability and deep hardening properties of the photosensitive resin composition and the appearance and reflectivity of the solder resist layer formed therefrom, and based on This knowledge led to the completion of the present invention.

According to the composition (X) of this embodiment, even if titanium oxide is contained, developability and deep hardenability can be improved, and the appearance and reflectance of the solder resist layer can be improved. The reason why the composition (X) can exhibit the above-mentioned effects by having the above-mentioned structure is not clear yet, but it can be estimated as follows. It is considered that in the composition (X), in addition to the proportion of titanium oxide (E) being above the aforementioned value and the weight average molecular weight (Mw) of the resin (A) being within the aforementioned range, the resin (A) also contains a molecular weight of 450 or greater And the oligomer part of 1000 or less will further improve the dispersibility of titanium oxide (E). By improving the dispersibility of titanium oxide (E), the reflectivity and gloss of the solder resist layer will be improved. In addition, in addition to the improvement in the dispersibility of titanium oxide (E), it is thought that the presence of oligomer portions in the resin (A) further homogenizes properties such as hardenability in the solder resist layer. That is, since the oligomer moiety has a carboxyl group, the photohardenability in the solder resist layer becomes more uniform, the development point becomes shorter, and the allowable range of drying time becomes wider, thereby improving the developability. Since the oligomer part has an ethylenically unsaturated group, it is thought that the thermal hardenability in the solder resist layer can be made more uniform, and the balance between surface hardening and deep hardening can be better, so that the deep hardenability can be improved. In addition, by achieving a good balance between surface hardening and deep hardening, the occurrence of lines in the solder resist layer can be suppressed and the appearance can be improved. In this way, according to the present invention, it is possible to provide a photosensitive resin composition that can improve developability and deep hardenability even if it contains titanium oxide, and can also improve the appearance and reflectance of the solder resist layer.

The composition (X) preferably contains an antioxidant (F) and a dispersant (G) in addition to the components (A) to (E), and the component (A) may be included in the range that does not impair the effect of the present invention. ) ~ (G) other ingredients (H), etc. Each component is explained below.

[Carboxyl-containing resin (A)] The so-called "carboxyl group-containing resin" means a resin having a carboxyl group. The composition (X) can be thermally cured by reacting the carboxyl group of the resin (A) and the epoxy group of the epoxy resin (D). The acid value of the resin (A) is preferably 55 mgKOH/g or more and 145 mgKOH/g or less. In this case, the thermosetting property of the composition (X) can be further improved, and the developability can be further improved. The acid value of the resin (A) is more preferably 65 mgKOH/g or more and 130 mgKOH/g or less, still more preferably 75 mgKOH/g or more and 120 mgKOH/g or less. The "acid value" means the number of milligrams of potassium hydroxide required to neutralize 1 g of solid content of resin (A).

The resin (A) is a vinyl polymer and has a residue having a carboxyl group (hereinafter also referred to as a carboxyl group-containing residue) as a monomer unit. The so-called "vinyl polymer" refers to a polymer obtained by polymerizing a monomer composition containing a monomer having an vinyl carbon-carbon double bond. The resin (A) may have, in addition to a residue derived from a monomer having an ethylenic carbon-carbon double bond, a residue derived from a monomer having an acetylenic carbon-carbon triple bond, a residue derived from a phenolic compound and Residues of aldehyde compounds, residues derived from carboxylic acid compounds and alcohol compounds or amine compounds, etc.

Furthermore, the resin (A) has an ethylenically unsaturated group in the side chain. The "side chain" means a chain other than the main chain among the atomic chains constituting the resin (A), and the "main chain" means the longest chain among the atomic chains constituting the resin (A). The term "ethylenically unsaturated group" means a group containing an ethylenic carbon-carbon double bond. Examples of the ethylenically unsaturated group include alkenyl groups such as vinyl and allyl groups; (meth)acrylyl groups; vinyl aromatic groups such as styryl groups and the like. The so-called "(meth)acrylyl group" means one or both of acrylyl group and methacrylyl group.

Carboxyl-containing residues are generally formed from monomers with carboxyl groups and vinyl carbon-carbon double bonds. Examples of such monomers include unsaturated carboxylic acids such as (meth)acrylic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, propynoic acid, oleic acid, and vinyl benzoic acid. Acid etc. The so-called "(meth)acrylic acid" means one or both of acrylic acid and methacrylic acid.

Resin (A) may have residues other than carboxyl group-containing residues. Examples of monomers that can be given other residues include (meth)acrylate, aromatic vinyl compounds, substituted or unsubstituted ethylene, unsaturated nitriles, and the like.

Examples of (meth)acrylates include (meth)acrylic alkanes such as (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and the like. Esters; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate; aromatic (meth)acrylate esters such as phenyl (meth)acrylate and benzyl (meth)acrylate. The so-called "(meth)acrylate" means one or both of acrylate and methacrylate.

Examples of aromatic compounds include: styrene; α-methylstyrene; substituted o-tostyrene, m-toluene, p-toluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc. Styrene; vinyl naphthalene, etc.

Examples of substituted ethylene include olefins such as propylene, butene, and vinylcyclohexane; 4-hydroxy-1-butene, and the like.

Examples of the unsaturated nitrile compound include (meth)acrylonitrile, α-chloro(meth)acrylonitrile, α-ethyl(meth)acrylonitrile, vinylene cyanide, and the like.

The resin (A) can be synthesized, for example, by introducing an ethylenically unsaturated group into the side chain of a vinyl polymer having a carboxyl group-containing residue. Specifically, the resin (A) can be prepared by, for example, combining a carboxyl group of a vinyl polymer having a carboxyl group-containing residue and a compound having an epoxy group and an ethylenically unsaturated group (hereinafter also referred to as epoxy-containing vinyl). Sexually unsaturated compounds) are synthesized by reaction. That is, the resin (A) preferably contains a reaction product of a vinyl polymer having a carboxyl group-containing residue and an epoxy group-containing ethylenically unsaturated compound.

Examples of the epoxy group-containing ethylenically unsaturated compound include: (meth)acrylate containing glycidyl acrylate, (meth)propylene 3,4-epoxycyclohexyl, and other epoxy group-containing (meth)acrylates; Vinyl glycidyl ether and other epoxy group-containing vinyl compounds.

A vinyl polymer having a carboxyl group-containing residue can be synthesized, for example, in the presence of a radical polymerization initiator and in a solvent such as dipropylene glycol monomethyl ether, adding a vinyl polymer having a carboxyl group and an vinyl carbon -The monomer composition of the carbon double bond monomer and other monomers included as necessary undergoes a polymerization reaction. The temperature of the polymerization reaction is, for example, 50°C or more and 150°C or less, preferably 60°C or more and 90°C or less. The polymerization reaction time is, for example, 1 hour or more and 10 hours or less, preferably 3 hours or more and 7 hours or less.

Examples of the radical polymerization initiator include: azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'- Azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyric acid dimethyl ester and other azo Polymerization initiator; peroxide polymerization initiator such as benzyl peroxide, tertiary butyl hydroperoxide, cumene hydroperoxide, etc.

When synthesizing a vinyl polymer having a carboxyl group-containing residue, the amount of the radical polymerization initiator used is, when Mw is set to 10,000 or more, relative to 100 parts by mass of the monomer having an ethylenic carbon-carbon double bond, It is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and still more preferably 5 parts by mass or less. The usage amount is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, and still more preferably 2 parts by mass or more. By setting the usage amount of the radical polymerization initiator within the aforementioned range, the Mw of the resin (A) can be adjusted to a more appropriate size. In addition, when the Mw is less than 10,000, the usage amount of the radical polymerization initiator is preferably 1 part by mass or more, more preferably 4 parts per mass part of the monomer having an ethylenic carbon-carbon double bond. Parts by mass or more, more preferably 10 parts by mass or more, particularly preferably 20 parts by mass or more. By setting the usage amount of the radical polymerization initiator within the above range, the Mw of the obtained polymer can be further reduced, and as a result, the proportion of the oligomer part in the resin (A) can be increased. The upper limit of the usage amount of the radical polymerization initiator is not particularly limited, but is, for example, 50 parts by mass or less.

When synthesizing polymers with carboxyl-containing residues, it is preferred to use chain shift agents. That is, it is preferable that at least part of the resin (A) is a polymerization reaction product using a chain transfer agent. By using a chain shift agent in the polymerization reaction, the Mw of the obtained polymer can be further reduced, and as a result, the proportion of the oligomer part in the resin (A) can be increased.

Examples of the chain transfer agent include: unsaturated hydrocarbon compounds such as α-methylstyrene dimer, α-terpene, dipentene, and terpinene; n-butyl mercaptan, n-octyl mercaptan, n- Thiol compounds such as decylmercaptan, n-dodecylmercaptan, and 2-ethylhexylmercaptoacetate; halogen compounds such as carbon tetrachloride, dichloromethane, bromoform, etc. The chain moving agent preferably contains an unsaturated hydrocarbon compound, and more preferably contains α-methylstyrene dimer. By using an unsaturated hydrocarbon compound as a chain transfer agent, an ethylenically unsaturated group can be introduced into the resin (A) and the terminal of the oligomer contained in the resin (A).

The usage amount of the chain migration agent is preferably 1 part by mass or more, more preferably 2 parts by mass or more, further preferably 8 parts by mass or more, and particularly preferably 15 parts by mass or more based on 100 parts by mass of the ethylenically unsaturated monomer. . By setting the usage amount of the chain transfer agent within the above range, the Mw of the obtained polymer can be further reduced, and as a result, the proportion of the oligomer part in the resin (A) can be increased.

The resin (A) can be synthesized, for example, by mixing a vinyl polymer having a carboxyl group-containing residue and a compound having an epoxy group and an ethylenically unsaturated group, and adding a polymerization inhibitor such as hydroquinone. In the presence of catalysts such as dimethylbenzylamine and dipropylene glycol monomethyl ether, an addition reaction is carried out between carboxyl groups and epoxy groups.

In addition to the above method, a vinyl polymer having a carboxyl group-containing residue can also be synthesized by, for example, the following method: combining the epoxy group of a vinyl polymer having an epoxy group-containing residue, and a carboxyl group and vinyl polymer. After reacting the carboxyl group of the compound with a sexually unsaturated group, it is reacted with a polycarboxylic acid or a polycarboxylic acid anhydride.

(weight average molecular weight) In the composition (X), it is important that the weight average molecular weight (Mw) of the resin (A) is 10,000 or more and 100,000 or less. When the Mw of the resin (A) is less than 10,000, the deep curability of the photosensitive resin composition decreases, and lines and the like may occur in the solder resist layer, resulting in poor appearance. In addition, the heat-resistant yellowing of the solder resist layer at this time will be reduced. If the Mw of the resin (A) exceeds 100,000, the developability of the composition (X) will decrease.

The Mw of the resin (A) is preferably 15,000 or more, more preferably 20,000 or more, further preferably 23,000 or more. The Mw of the resin (A) is preferably 80,000 or less, more preferably 60,000 or less, still more preferably 40,000 or less.

The Mw of the resin (A) is generally calculated from the results of molecular weight measurement using gel permeation chromatography (GPC). Molecular weight measurement by GPC can be carried out under the following conditions, for example.

GPC device: SHODEX SYSTEM 11 manufactured by Showa Denko Co., Ltd.; Pipe string: four series connections of SHODEX KF-800P, KF-005, KF-003 and KF-001 manufactured by Showa Denko Co., Ltd.; Mobile phase: tetrahydrofuran; Flow: 1mL/min; Column temperature: 45℃; Detector: Differential refractive index (RI) detector; Standard material: polystyrene.

(Oligomer part) In the composition (X), it is important that the resin (A) contains an oligomer part with a molecular weight of 450 or more and 1000 or less. This oligomer part is a part with a molecular weight of 450 or more and 1000 or less in the resin (A) which is a vinyl polymer having a carboxyl group-containing residue and an ethylenically unsaturated group in a side chain. The resin contained in the oligomer part preferably has at least one of a carboxyl-containing residue and an ethylenically unsaturated group, and more preferably has both a carboxyl-containing residue and an ethylenically unsaturated group.

The proportion of the oligomer part with a molecular weight of 450 to 1000 in the resin (A) is preferably 0.1% or more, more preferably 0.2% or more, further preferably 0.3% or more, and particularly preferably 0.4% or more. The proportion of the oligomer part with a molecular weight of 450 to 1000 in the resin (A) is preferably 9% or less, more preferably 3% or less, further preferably 2% or less, and particularly preferably 1% or less. By setting the proportion of the oligomer part within the aforementioned range, the deep hardenability of the composition (X) and the yellowing resistance of the solder resist layer can be further improved. Generally speaking, the proportion of the oligomer part in the resin (A) with a molecular weight of 450 or more and 1000 or less can be determined by GPC using a differential refractive index detector. The following area of the oligomer part is measured as a ratio of 100% of the total area. That is, the ratio (%) of the oligomer part means "(area derived from the oligomer part) × 100/total area derived from the resin (A)". Regarding GPC, the molecular weight of the oligomer can be determined by using polystyrene as a standard material. In addition, the total area derived from the resin (A) and the area derived from the oligomer portion with a molecular weight of 450 or more and 1000 or less can be obtained by the area calculation method based on general baseline processing and peak processing in GPC. out. Specifically, all peaks in GPC are divided into peaks originating from the resin (A) and components other than the resin (A) originating from solvents, monomers, compounds having an epoxy group and an ethylenically unsaturated group, etc. After the portion, the portion derived from the oligomer portion with a molecular weight of 450 or more and 1000 or less is determined among the peaks of the portion derived from the resin (A). In this way, the proportion (%) of the oligomer part is calculated by the formula (area of the oligomer part) × 100/total area of the resin (A).

One type of resin (A) may be used alone, or two or more types of resins having mutually different Mw may be mixed and used in order to adjust the ratio of the oligomer part. The resin (A) may be a mixture of a resin with an Mw of 10,000 or more and containing no oligomer part, and a resin with an Mw of less than 10,000 and containing an oligomer part.

The proportion of the resin (A) is preferably 10 mass% or more, more preferably 20 mass% or more, based on the solid content of the composition (X). The ratio is preferably 60 mass% or less, more preferably 50 mass% or less. The "solid content" of the composition (X) means the total of components other than the solvent in the composition (X).

[Photopolymerization initiator (B)] The photopolymerization initiator (B) is a component that can improve the photosensitivity of the photosensitive resin composition. By containing the photopolymerization initiator (B), the composition (X) can harden the exposed portion. One type or two or more types of photopolymerization initiators (B) can be used.

Examples of the photopolymerization initiator (B) include a phosphine oxide-based photopolymerization initiator, an α-hydroxyalkyl phenyl ketone-based photopolymerization initiator, and the like.

Examples of the acylphosphine oxide-based photopolymerization initiator include: 2,4,6-Trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and other monomethylphosphine oxides are photopolymerized starter; Bis(2,4,6-trimethylbenzyl)phenylphosphine oxide, bis(2,6-dichlorobenzyl)phenylphosphine oxide, bis(2,6-dichlorobenzyl)phenylphosphine oxide methyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzylyl) )-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzyl)phenylphosphine oxide, bis(2,6-dimethoxybenzyl)-2,4,4 -Bisylphosphine oxide photopolymerization initiators such as trimethylpentylphosphine oxide and bis(2,6-dimethoxybenzyl)-2,5-dimethylphenylphosphine oxide.

Examples of the α-hydroxyalkyl phenyl ketone photopolymerization initiator include: 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2- Hydroxy-2-methylpropyl)benzyl]phenyl}-2-methylpropan-1-one, etc.

Examples of photopolymerization initiators (B) other than those mentioned above include: benzoin and alkyl ethers thereof; acetophenone-based photopolymerization initiators such as acetophenone and benzyldimethyl ketal; 2-methyl Anthraquinone series photopolymerization initiators such as anthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone Thioxanthone photopolymerization initiators such as xanthone and 2,4-diisopropylthioxanthone; diphenyl ketone, 4-benzoyl-4'-methyldiphenyl sulfide and other Methone-based photopolymerization initiator; xanthone (xanthone)-based photopolymerization initiator such as 2,4-diisopropylxanthone; 2-methyl-1-[4-(methylthio)benzene base]-2-morpholino-1-propanone and other nitrogen-containing photopolymerization initiators; 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one and 2-(dimethylamino)-2-[(4-tolyl)methyl ]-1-[4-(4-morpholinyl)phenyl]-1-butanone and other α-amine alkyl phenyl ketone photopolymerization initiators; 1,2-octanedione, 1-[4 -(phenylthio)-,2-(O-benzoyl oxime)] and ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3 -Oxime ester photopolymerization initiator such as -,1-(O-acetyl oxime), etc.

The photopolymerization initiator (B) preferably contains a phosphine oxide-based photopolymerization initiator. In this case, the developability and deep hardening property of the composition (X) can be further improved. The phosphine oxide-based photopolymerization initiator preferably contains bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. In this way, by using a substance having light absorption in a long wavelength range as the photopolymerization initiator (B), the deep curability of the composition (X) can be further improved.

When the photopolymerization initiator (B) contains a hydroxyphosphine oxide-based photopolymerization initiator, the proportion of the hydroxyphosphine oxide-based photopolymerization initiator in the photopolymerization initiator (B) is preferably 1 mass % or more, more preferably 5 mass% or more, further preferably 10 mass% or more, and particularly preferably 20 mass% or more. The ratio is, for example, 100 mass% or less, preferably 80 mass% or less, more preferably 50 mass% or less.

Furthermore, the photopolymerization initiator (B) preferably contains an α-hydroxyalkyl phenyl ketone-based photopolymerization initiator in addition to the acylphosphine oxide-based photopolymerization initiator. In this case, the developability and deep hardenability of the composition (X) can be further improved, and the surface hardenability can also be improved. Furthermore, the solubility of the photopolymerization initiator can be improved, so the storage of the composition (X) can be improved. Stability is further improved.

When the photopolymerization initiator (B) contains an α-hydroxyalkyl phenyl ketone photopolymerization initiator, the α-hydroxyalkyl phenyl ketone photopolymerization initiator in the photopolymerization initiator (B) The ratio is preferably 1 mass% or more, more preferably 10 mass% or more, and further preferably 50 mass% or more. The ratio is preferably 95 mass% or less, more preferably 85 mass% or less.

When the photopolymerization initiator (B) contains a acylphosphine oxide-based photopolymerization initiator and an α-hydroxyalkyl phenyl ketone-based photopolymerization initiator, the acyl group in the photopolymerization initiator (B) is oxidized The total ratio of the phosphine-based photopolymerization initiator and the α-hydroxyalkyl phenyl ketone-based photopolymerization initiator is preferably 10 mass% or more, more preferably 50 mass% or more, and further preferably 90 mass% or more . The ratio may be 100% by mass.

The ratio of the photopolymerization initiator (B) is preferably 0.1 parts by mass or more and 100 parts by mass or less based on 100 parts by mass of the resin (A). In this case, the resolution and deep hardenability of the composition (X) can be further improved. The ratio is more preferably from 1 part by mass to 90 parts by mass, further preferably from 10 parts by mass to 80 parts by mass, and particularly preferably from 20 parts by mass to 60 parts by mass.

The proportion of the photopolymerization initiator (B) relative to the solid content of the composition (X) is preferably 1 mass % or more and 30 mass % or less, more preferably 3 mass % or more and 20 mass % or less, and still more preferably It is 5 mass % or more and 15 mass % or less.

[Photopolymerizable compound (C)] The photopolymerizable compound (C) is a component that can impart photocurability to the photosensitive resin composition. The photopolymerizable compound (C) generally contains a compound having an ethylenically unsaturated group. However, the resin (A) is not a photopolymerizable compound (C). By having an ethylenically unsaturated group, the photopolymerizable compound (C) can photoharden the composition (X), and the photopolymerizable compounds (C) and/or the photopolymerizable compounds (C) and the composition (X) having The cross-linking reaction between the ethylenically unsaturated resins (A) can form a cross-linked structure in the exposed area of the composition (X). One type or two or more types of photopolymerizable compounds can be used.

Examples of the photopolymerizable compound (C) include monofunctional (meth)acrylates such as 2-hydroxyethyl methacrylate; diethylene glycol di(meth)acrylate, and trimethylolpropane. Difunctional (meth)acrylates such as di(meth)acrylate and tricyclodecane dimethanol di(meth)acrylate; trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate Acrylate, EO modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated isocyanurate tri(meth)acrylate, ε-caprolactone modified Trifunctional (meth)acrylates such as 2-(meth)acryloyloxyethyl)isocyanurate, ethoxylated glyceryl tri(meth)acrylate; pentaerythritol tetra(methyl)acrylate ) Acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ε-caprolactone modified pentaerythritol hexa(meth)acrylate and other four or more functional (meth)acrylates and other multifunctional (meth)acrylates, etc.

The photopolymerizable compound (C) preferably contains a trifunctional (meth)acrylate, that is, a compound having three (meth)acrylyl groups in one molecule. If the photopolymerizable compound (C) contains a trifunctional (meth)acrylate, a more appropriate cross-linked structure can be formed by exposure. As a result, the developability and deep hardening properties of the composition (X) and the solder resist layer can be improved. The appearance is further improved.

The ratio of the photopolymerizable compound (C) is preferably 1 part by mass or more and 200 parts by mass or less based on 100 parts by mass of the resin (A). In this case, the developability and deep hardening property of the composition (X) can be further improved. The ratio is more preferably from 5 parts by mass to 150 parts by mass, further preferably from 20 parts by mass to 100 parts by mass, and particularly preferably from 50 parts by mass to 100 parts by mass.

The proportion of the photopolymerizable compound (C) is preferably 1 mass % or more and 40 mass % or less, more preferably 5 mass % or more and 30 mass % or less based on the solid content of the composition (X), and still more preferably 10 mass% or more and 20 mass% or less.

[Epoxy resin (D)] Epoxy resin (D) is a component that can impart thermosetting properties to the photosensitive resin composition. The epoxy resin (D) is a compound having one or more epoxy groups in one molecule, preferably two or more epoxy groups in one molecule. One type or two or more types can be used for the epoxy resin (D).

Examples of the epoxy resin (D) include crystalline epoxy resin, amorphous epoxy resin, and the like. The so-called "crystalline epoxy resin" means an epoxy resin with a melting point, and the so-called "amorphous epoxy resin" means an epoxy resin without a melting point. The melting point of the crystalline epoxy resin is, for example, 70°C or more and 180°C or less.

Examples of crystalline epoxy resins include: 1,3,5-shen(2,3-epoxypropyl)-1,3,5-triazaphenyl-2,4,6(1H,3H , 5H)-triketone, hydroquinone type crystalline epoxy resin (as a specific example, model YDC-1312 manufactured by Nippon Steel and Sumitomo Chemical Co., Ltd.), biphenyl type crystalline epoxy resin (as a specific example, Mitsubishi Chemical Co., Ltd.), diphenyl ether type crystalline epoxy resin (as a specific example, model YSLV-80DE manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), bisphenol type crystalline epoxy resin ( Specific examples include models YSLV-70XY and YSLV-80XY manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), ethyl ethane type crystalline epoxy resin (model GTR-1800 manufactured by Nippon Kayaku Co., Ltd. as a specific example ), bisphenol-type crystalline epoxy resin, etc.

Examples of the amorphous epoxy resin include: phenol novolak type epoxy resin (a specific example is model EPICLON N-775 manufactured by DIC Co., Ltd.), a cresol novolac type epoxy resin (a specific example is EPICLON N-775 manufactured by DIC Co., Ltd.), and a cresol novolac type epoxy resin (a specific example is Model EPICLON N-695 manufactured by DIC Co., Ltd.), bisphenol A novolak type epoxy resin (model EPICLON N-865 manufactured by DIC Co., Ltd. as a specific example), bisphenol A type epoxy resin (model EPICLON N-865 manufactured by DIC Co., Ltd. as a specific example) Examples include model jER1001 manufactured by Mitsubishi Chemical Co., Ltd.), bisphenol F-type epoxy resin (model jER4004P manufactured by Mitsubishi Chemical Co., Ltd. as a specific example), and bisphenol S-type epoxy resin (model jER4004P manufactured by Mitsubishi Chemical Co., Ltd. as a specific example). Co., Ltd. model EPICLON EXA-1514), bisphenol AD type epoxy resin, biphenyl novolac type epoxy resin (as a specific example, Nippon Kayaku Co., Ltd. model NC-3000), hydrogenated bisphenol A type epoxy resin (specific examples are model ST-4000D manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), naphthalene type epoxy resin (specific examples are model numbers EPICLON HP-4032 and EPICLON HP-4700 manufactured by DIC Co., Ltd. , EPICLON HP-4770), third-grade butylcatechol type epoxy resin (as a specific example, model EPICLON HP-820 manufactured by DIC Co., Ltd.), dicyclopentadiene type epoxy resin (as a specific example, DIC Co., Ltd. model EPICLON HP-7200), adamantane type epoxy resin (a specific example is ADAMANTATE X-E-201 manufactured by Idemitsu Kosan Co., Ltd.), special bifunctional epoxy resin (a specific example is Models YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Co., Ltd.; Models EPICLON TSR-960, EPICLON TER-601, EPICLON TSR-250-80BX, EPICLON 1650-75MPX, EPICLON EXA-4850, manufactured by DIC Co., Ltd. EPICLON EXA-4816, EPICLON EXA-4822 and EPICLON EXA-9726; model YSLV-120TE manufactured by Nippon Steel and Sumitomo Metal Chemical Co., Ltd.), rubbery core-shell polymer modified bisphenol A type epoxy resin (as specific examples are Model MX-156 manufactured by KANEKA Co., Ltd.) and rubbery core-shell polymer modified bisphenol F-type epoxy resin (model MX-130 manufactured by KANEKA Co., Ltd. as a specific example).

The epoxy resin (D) preferably contains a crystalline epoxy resin. In this case, the developability and deep hardening property of the composition (X) can be further improved.

The epoxy equivalent of the epoxy resin (D) is, for example, 50 g/eq or more and 500 g/eq or less, preferably 80 g/eq or more and 250 g/eq or less. The so-called "epoxy equivalent" refers to the gram mass of epoxy resin having 1 gram equivalent of epoxy groups.

The equivalent of the epoxy group of the epoxy resin (D) relative to the equivalent of the carboxyl group of the resin (A) is preferably 0.7 times or more and 2.5 times or less, more preferably 0.7 times or more and 2.3 times or less, and further Preferably, it is 0.7 times or more and 2.0 times or less.

The ratio of the epoxy resin (D) to 100 parts by mass of the resin (A) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, further preferably 5 parts by mass or more, and particularly preferably 10 parts by mass or more. . In this case, the thermosetting property of the composition (X) can be further improved, and as a result, the developability and the deep curability can be further improved. The ratio is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, further preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less. At this time, the appearance of the solder resist layer can be further improved.

The ratio of the epoxy resin (D) to the solid content of the composition (X) is preferably 1 mass % or more and 30 mass % or less, more preferably 2 mass % or more and 20 mass % or less, and still more preferably 3 Mass% or more and 15 mass% or less.

[Titanium oxide (E)] Titanium oxide (E) is an oxide of titanium, and examples thereof include TiO ₂ , TiO, Ti _n O _{2n ｰ 1} (n=4 to 9), Ti ₂ O ₅ , and Ti ₂ O ₃ Among the substances represented, TiO ₂ (titanium dioxide) is preferred. One type or two or more types of titanium oxide (E) can be used.

Examples of titanium oxide (E) include rutile titanium oxide, anatase titanium oxide, rhombohedral titanium oxide, and the like. One type or two or more types of titanium oxide (E) can be used.

Rutile titanium oxide is generally produced industrially by the chlorine method or the sulfuric acid method. Examples of rutile titanium oxide include models R-25, R-21, R-32, R-7E, R-5N, R-61N, R-62N, and R- manufactured by Sakai Chemical Industry Co., Ltd. 42. R-45M, R-44, R-49S, R-79, GTR-100, GTR-300, D-918, TCR-29, TCR-52, FTR-700; models manufactured by Ishihara Industrial Co., Ltd. R-550, R-580, R-630, R-820, CR-50, CR-58, CR-60, CR-90, CR-97, CR-953; Model TR manufactured by Fuji Titanium Industry Co., Ltd. -600, TR-700, TR-750, TR-840; models KR-270, KR-310, KR-380, etc. manufactured by Titanium Industrial Co., Ltd.

As anatase titanium oxide, a conventional material can be used. Commercially available products of anatase titanium oxide include, for example, models A-110, TCA-123E, A-190, A-197, SA-1, and SA-1L manufactured by Sakai Chemical Industry Co., Ltd.; Ishihara Models A-100, A-220, W-10 manufactured by Industrial Co., Ltd.; Models TA-100, TA-200, TA-300, TA-400, TA-500, TP- manufactured by Fuji Titanium Industrial Co., Ltd. 2; Models JA-1, JA-3, JA-4, JA-5, JA-C manufactured by TAYCA Co., Ltd.; Models KA-10, KA-15, KA-20, KA manufactured by Titanium Industry Co., Ltd. -30 etc.

The harzburgite-type titanium oxide can be produced by subjecting harzburgite-type Li _0.5 TiO ₂ to a lithium desorption process by chemical oxidation.

Titanium oxide (E) is generally in the form of particles. Examples of the particle shape of titanium oxide (E) include plate shape, spherical shape, needle shape, amorphous shape, and the like. The average particle diameter of titanium oxide (E) is, for example, 10 μm or less, preferably 0.001 μm or more and 10 μm or less, more preferably 0.01 μm or more and 5 μm or less.

Titanium oxide (E) preferably contains rutile titanium oxide. In this case, the heat resistance of the composition (X) can be further improved, and as a result, the heat yellowing resistance of the solder resist layer can be further improved.

In the composition (X), it is important that the ratio of the titanium oxide (E) is 20 parts by mass or more relative to 100 parts by mass of the resin (A). By setting the proportion of titanium oxide (E) above the aforementioned range, the composition (X) can have a higher reflectance. The ratio is preferably 30 parts by mass or more, more preferably 50 parts by mass or more, further preferably 70 parts by mass or more, and particularly preferably 90 parts by mass or more. The upper limit of the proportion of titanium oxide (E) is not particularly limited, but it is, for example, 300 parts by mass or less, preferably 250 parts by mass or less, and more preferably 200 parts by mass or less based on 100 parts by mass of the resin (A).

The ratio of titanium oxide (E) to the solid content of the composition (X) is preferably 5 mass% or more, more preferably 10 mass% or more, further preferably 15 mass% or more, and particularly preferably 20 mass% or more. . The upper limit of the proportion of titanium oxide (E) is not particularly limited, but is, for example, 50 mass% or less, preferably 40 mass% or less.

[Antioxidant (F)] Antioxidants are components that can contribute to improving the heat discoloration resistance of the solder resist layer. By containing the antioxidant (F), the composition (X) can further improve the heat-resistant yellowing of the solder resist layer. As the antioxidant (F), one type or two or more types can be used in the composition (X).

Examples of the antioxidant (F) include pentaerythritol 4[3-(3,5-di-tertiary butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5- Hindered phenol antioxidants such as di-tertiary butyl-4-hydroxyphenyl)propionate; tetrakis(1,2,2,6,6-pentamethyl-4-piperidine)-1,2,3 , 4-butanetetracarboxylate and other hindered amine antioxidants; bis(2,6-di-tertiary butyl-4-methylphenyl) pentaerythritol diphosphite and other phosphorus antioxidants; 2,2 -Bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate] Sulfur antioxidants, etc.

The antioxidant (F) preferably contains a hindered phenol antioxidant. When the antioxidant (F) contains a hindered phenol antioxidant, the heat-resistant yellowing of the solder resist layer can be further improved.

The melting point of the antioxidant (F) is preferably 50°C or more and 150°C or less. In this case, the bleeding of the antioxidant from the solder resist layer and the precipitation of the crystals of the antioxidant can be prevented, and the uniformity of the surface of the solder resist layer can be improved. Examples of such antioxidants (F) include model Irganox 1010 manufactured by BASF Co., Ltd. (melting point: 110 to 125°C), model ADEKASTAB AO-60 manufactured by ADEKA Co., Ltd. (110 to 130°C), and the like.

The ratio of the antioxidant (F) to the solid content of the composition (X) is, for example, 0.01 mass % or more and 3 mass % or less, preferably 0.1 mass % or more and 1.5 mass % or less.

[Dispersant (G)] The dispersant (G) is a component for further improving the dispersibility of the particles in the composition. Examples of the dispersant (G) include polymer dispersants having functional groups. Examples of the functional group include: acidic functional groups such as phosphate group, carboxyl group, and sulfonic acid group; bases of these acidic functional groups; primary amino group, secondary amino group, or tertiary amino group; quaternary ammonium salt group; pyridine , pyrimidine, pyrazine and other basic functional groups derived from nitrogen-containing aromatic heterocyclic groups. As the functional group that the dispersant (G) has, a phosphate group is preferred. Since the dispersant (G) has a phosphate group, the dispersibility of the titanium oxide (E) in the composition (X) can be further improved, thereby improving the developability, deep hardening properties and solder resist layer of the composition (X). The appearance is further improved. When the dispersing agent (G) has an acidic functional group, the acid value of the dispersing agent (G) is, for example, 50 mgKOH/g or more and 200 mgKOH/g. As the dispersant (G), one type or two or more types of the composition (X) can be used.

The proportion of the dispersant (G) relative to the solid content of the composition (X) is, for example, 0.01 mass % or more and 5 mass % or less, preferably 0.1 mass % or more and 2 mass % or less.

[Other ingredients (H)] Examples of other components (H) include: melamine or its derivatives; defoamer; hardener; hardening accelerator; barium sulfate, silicon dioxide, talc, bentonite, calcium carbonate, barium titanate, aluminum hydroxide, etc. Inorganic filling materials other than titanium oxide (E); coupling agents such as silane coupling agent; surfactants; leveling agents; thixotropic agents; antihalation agents; flame retardants; solvents, etc. As the other component (H), one type or two or more types can be used in the composition (X).

(Melamine or its derivatives) By containing at least one kind of melamine or its derivatives, the composition (X) can further improve the adhesion between the hardened product of the composition (X) and metals such as copper. In this case, the composition (X) can be particularly suitably used as an insulating material for printed wiring boards. In addition, the plating resistance of the hardened material of composition (X), that is, the whitening resistance during electroless nickel/gold plating treatment, is improved.

Melamine is 2,4,6-triamino-1,3,5-triazaphenyl. Examples of melamine derivatives include compounds having one triazine ring and an amine group in one molecule. Specific examples include: guanamine; acetoguanamine; benzoguanidine Amine (benzoguanamine); 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine , 2-vinyl-4,6-diamino-S-triazaphenyl-isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S- S-triazine derivatives such as triazine and isocyanuric acid adducts; reaction products of melamine and acid anhydride such as melamine-tetrahydrophthalate, etc. When the composition (X) contains melamine or its derivatives, the proportion of melamine or its derivatives relative to the solid content of the composition (X) is, for example, 0.01 mass % or more and 5 mass % or less, preferably 0.1 mass %. More than 2% by mass.

(defoaming agent) Examples of the defoaming agent include: silicone defoamer such as model KS-66 manufactured by Shin-Etsu Chemical Industry Co., Ltd.; non-silicone defoamer such as model FOAMKILLER NSI-0.00 manufactured by Aoki Oils and Fats Industry Co., Ltd. wait. When the composition (X) contains a defoaming agent, the proportion of the defoaming agent relative to the solid content of the composition (X) is, for example, 0.001 mass % or more and 2 mass % or less, preferably 0.01 mass % or more and 1 mass %. %the following.

(solvent) Composition (X) may contain a solvent. When the composition (X) contains a solvent, preparation becomes easier. The solvent is not particularly limited, and examples thereof include organic solvents such as glycol ethers such as dipropylene glycol monomethyl ether. The reaction solvent used for the synthetic resin (A) can also be directly used as the solvent of the composition (X). When the composition (X) contains a solvent, the proportion of the solvent relative to the entire composition (X) is, for example, 1 mass % or more and 80 mass % or less, preferably 5 mass % or more and 40 mass % or less.

The composition (X) can be prepared by blending the above raw materials of the composition (X) and kneading them using a conventional kneading method such as a three-roller mill, a ball mill, a sand mill, etc.

〈Dry film〉 The dry film of this embodiment contains the aforementioned composition (X), specifically a dry coating film of the composition (X). The dry film of this embodiment can be formed by coating the composition (X) on, for example, a base film, drying the obtained wet coating film to remove the solvent, etc., and can be formed into a dry film with the base film attached. obtain. Examples of the base film include polyethylene terephthalate (PET) films. Examples of the coating method of the composition (X) include a dipping method, a spray method, a spin coating method, a roll coating method, a curtain coating method, a screen printing method, and the like. The temperature during drying is, for example, 50°C or more and 120°C or less. The drying time is, for example, 1 minute or more and 2 hours or less. The thickness of the dry film is, for example, 1 μm or more and 100 μm or less.

The dry film of this embodiment can be suitably used as an electrically insulating material for a printed wiring board, and is particularly suitably used for forming electrically insulating layers such as a solder resist layer, a plating resist layer, an etching resist layer, and an interlayer insulating layer. .

〈Solder resist〉 The solder resist of this embodiment contains a cured product of the aforementioned composition (X), specifically a cured film of the composition (X). The solder resist of this embodiment can be formed, for example, by applying the composition (X) to at least a part of the surface of a base material such as a printed circuit board, and then thermally curing the obtained coating layer. Examples of a method for thermally curing the composition (X) include heating. The heating temperature is, for example, 100°C or more and 250°C or less, preferably 120°C or more and 200°C or less. The heating time is, for example, 1 minute or more and 10 hours or less, preferably 10 minutes or more and 3 hours or less. In the formation of the solder resist, photohardening and development may be performed before thermal hardening. The thickness of the solder resist is, for example, 1 μm or more and 100 μm or less.

〈Printed circuit board〉 The printed wiring board of this embodiment is provided with a solder resist layer, and the solder resist layer contains the cured product of the aforementioned composition (X). The printed wiring board of this embodiment can be formed, for example, by forming a solder resist layer on a printed wiring board. The solder resist layer can be formed, for example, by applying the composition (X) to a printed circuit board (coating step), and irradiating at least a part of the obtained coating layer with active energy rays to photo-harden it. After the (photohardening step), the unexposed portion of the coating layer is removed by development (development step), and then the coating layer after the development step is thermally hardened (thermal hardening step). Furthermore, photohardening can be further performed after the development step or the thermal hardening step, or at two time points after the development step and the thermal hardening step.

Irradiation of active energy rays can be performed, for example, in a state of direct contact with a negative mask, or a method other than the method using a negative mask can be used, such as direct drawing to expose the coating layer. The direct drawing can be used to expose the coating layer. The method is to irradiate only the portion of the coating layer to be exposed with active energy rays emitted from the light source. The active energy rays to be irradiated can be appropriately selected depending on the composition of the composition (X), and examples thereof include ultraviolet rays, visible rays, near-infrared rays, and the like. The active energy ray is preferably ultraviolet light, and the ultraviolet light source can be selected from the group consisting of chemical lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, YAG lasers, LEDs, xenon lamps and metal halide lamps. The exposure dose of active energy rays is, for example, 10 mJ/cm ² or more and 5000 mJ/cm ² or less, preferably 100 mJ/cm ² or more and 800 mJ/cm ² or less. When the cured film is produced from a dry film, when the dry film is exposed, for example, the support may be peeled off from the dry film in advance and then the dry film may be exposed. Furthermore, the dry film may be exposed by irradiating the dry film with ultraviolet rays penetrating the support while the support remains overlapped with the dry film, and then the support may be peeled off from the exposed dry film.

The developer used for development can be appropriately selected according to the composition of the composition (X), and examples thereof include sodium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium hydroxide, potassium hydroxide, Alkaline aqueous solutions such as ammonium hydroxide and lithium hydroxide; organic amine solutions such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine.

Thermal hardening can be implemented, for example, by heating the developed coating layer. The heating temperature is, for example, 100°C or more and 250°C or less, preferably 120°C or more and 200°C or less. The heating time is, for example, 1 minute or more and 10 hours or less, preferably 10 minutes or more and 3 hours or less, more preferably 20 minutes or more and 120 minutes or less.

The thickness of the solder resist layer is, for example, 1 μm or more and 100 μm or less. By operating in the above manner, a printed wiring board can be produced, which has a solder resist layer containing a hardened product of the composition (X). [Example]

The present invention will be specifically described below through examples, but the present invention is not limited to the examples.

〈Preparation of carboxyl-containing resin solution〉 (1) Synthesis example 1 Add the following ingredients to a four-neck flask equipped with a reflux cooler, a thermometer, a glass tube for nitrogen replacement and a stirrer: 38.5 parts by mass of methacrylic acid; 51.5 parts by mass of methyl methacrylate; 10 parts by mass of styrene; 160 parts by mass parts of dipropylene glycol monomethyl ether; and, 6 parts by mass of azobisisobutyronitrile. The solution in the four-necked flask was heated at 75° C. for 5 hours under a nitrogen gas flow to perform a polymerization reaction, thereby obtaining a copolymer solution with a concentration of 40% by mass. 0.05 parts by mass of hydroquinone, 34 parts by mass of glycidyl methacrylate, and 0.4 parts by mass of dimethylbenzylamine were added to the copolymer solution, and the addition reaction was performed by heating at 80° C. for 24 hours. . Thereby, a 47% by mass solution of the carboxyl group-containing resin A, which is a vinyl polymer having a carboxyl group-containing residue and an ethylenically unsaturated group located in a side chain, was obtained. The weight average molecular weight of the carboxyl group-containing resin A is 24,300. In addition, the carboxyl group-containing resin A does not have an oligomer portion with a molecular weight of 450 or more and 1,000 or less.

(2) Synthesis example 2 Add the following ingredients to a four-neck flask equipped with a reflux cooler, a thermometer, a glass tube for nitrogen replacement, and a stirrer: 38.5 parts by mass of methacrylic acid; 51.5 parts by mass of methyl methacrylate; 10 parts by mass of styrene; 3 parts by mass 160 parts by mass of α-methylstyrene dimer; 160 parts by mass of dipropylene glycol monomethyl ether; and 2 parts by mass of azobisisobutyronitrile. The solution in the four-necked flask was heated at 75° C. for 5 hours under a nitrogen gas flow to perform a polymerization reaction, thereby obtaining a copolymer solution with a concentration of 40% by mass. 0.05 parts by mass of hydroquinone, 34 parts by mass of glycidyl methacrylate, and 0.4 parts by mass of dimethylbenzylamine were added to the copolymer solution, and the addition reaction was performed by heating at 80° C. for 24 hours. . Thereby, a 47% by mass solution of the carboxyl group-containing resin B, which is a vinyl polymer having a carboxyl group-containing residue and an ethylenically unsaturated group located in a side chain, was obtained. The weight average molecular weight of the carboxyl group-containing resin B is 33,860. In addition, the carboxyl group-containing resin B does not have an oligomer part with a molecular weight of 450 or more and 1000 or less.

(3) Synthesis example 3 Add the following ingredients to a four-neck flask equipped with a reflux cooler, a thermometer, a glass tube for nitrogen replacement, and a stirrer: 38.5 parts by mass of methacrylic acid; 51.5 parts by mass of methyl methacrylate; 10 parts by mass of styrene; 20 parts by mass 160 parts by mass of α-methylstyrene dimer; 160 parts by mass of dipropylene glycol monomethyl ether; and 12 parts by mass of azobisisobutyronitrile. Under a nitrogen gas flow, the solution in the four-necked flask was heated at 75° C. for 5 hours to perform a polymerization reaction, thereby obtaining a copolymer solution with a concentration of 45% by mass. 0.05 parts by mass of hydroquinone, 34 parts by mass of glycidyl methacrylate, and 0.4 parts by mass of dimethylbenzylamine were added to the copolymer solution, and the addition reaction was performed by heating at 80° C. for 24 hours. . Thereby, a 51% by mass solution of the carboxyl group-containing resin C, which is a vinyl polymer having a carboxyl group-containing residue and an ethylenically unsaturated group located in a side chain, was obtained. The weight average molecular weight of the carboxyl group-containing resin C is 3884. In addition, the carboxyl group-containing resin C has an oligomer portion with a molecular weight of 450 or more and 1,000 or less.

(4) Synthesis example 4 Add the following ingredients to a four-neck flask equipped with a reflux cooler, a thermometer, a glass tube for nitrogen replacement, and a stirrer: 38.5 parts by mass of methacrylic acid; 51.5 parts by mass of methyl methacrylate; 10 parts by mass of styrene; 20 parts by mass 195 parts by mass of α-methylstyrene dimer; 195 parts by mass of dipropylene glycol monomethyl ether; and 22.5 parts by mass of azobisisobutyronitrile. The solution in the four-necked flask was heated at 75° C. for 5 hours under a nitrogen gas flow to perform a polymerization reaction, thereby obtaining a copolymer solution with a concentration of 42% by mass. 0.05 parts by mass of hydroquinone, 34 parts by mass of glycidyl methacrylate, and 0.4 parts by mass of dimethylbenzylamine were added to the copolymer solution, and the addition was performed by heating at 80° C. for 24 hours. reaction. Thereby, a 47% by mass solution of the carboxyl group-containing resin D, which is a vinyl polymer having a carboxyl group-containing residue and an ethylenically unsaturated group located in a side chain, was obtained. The weight average molecular weight of the carboxyl group-containing resin D is 2,994. Furthermore, the carboxyl group-containing resin D has an oligomer part with a molecular weight of 450 or more and 1,000 or less.

<Preparation of photosensitive resin composition> A photosensitive resin composition was obtained by kneading the mixture obtained by preparing the components shown in Table 1 described below using a three-roller mill in advance. In addition, the details of the components shown in Table 1 are as follows. -Photopolymerization initiator (B) ‧Photopolymerization initiator A: acylphosphine oxide series, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, manufactured by BASF Co., Ltd., model Irgacure 819. ‧Photopolymerization initiator B: acylphosphine oxide series, 2,4,6-trimethylbenzyldiphenylphosphine oxide, manufactured by BASF Co., Ltd., model Irgacure TPO. ‧Photopolymerization initiator C: α-hydroxyalkyl phenyl ketone series, 2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by BASF Co., Ltd., model Irgacure 1173. ‧Photopolymerization initiator D: α-hydroxyalkyl phenyl ketone series, 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF Co., Ltd., model Irgacure 184. -Photopolymerizable compound (C) ‧Photopolymerizable compound A: trimethylolpropane triacrylate (TMPTA). ‧Photopolymerizable compound B: a mixture of dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate (manufactured by Nippon Kayaku Co., Ltd., model KAYARAD DPHA). -Epoxy resin (D) ‧Epoxy resin A: crystalline epoxy compound, 1,3,5-shen(2,3-epoxypropyl)-1,3,5-triazaphenyl-2,4,6(1H, 3H,5H)-trione (high melting point type) (TEPIC-HB), epoxy equivalent 99g/eq. ‧Epoxy Resin B: Crystalline epoxy compound, hydroquinone type crystalline epoxy resin, manufactured by Nippon Steel and Sumitomo Metal Chemical Co., Ltd., model YDC-1312, epoxy equivalent 176g/eq. ‧Epoxy Resin C: Amorphous epoxy compound, hydrogenated bisphenol A type epoxy resin, manufactured by Nippon Steel and Sumitomo Metal Chemical Co., Ltd., model number ST-3000, epoxy equivalent 230g/eq. -Titanium oxide(E) ‧Titanium oxide A: Rutile titanium oxide made by sulfuric acid method, manufactured by Sakai Chemical Industry Co., Ltd., model R-79. ‧Titanium oxide B: Rutile titanium oxide made by chlorine method, manufactured by Ishihara Industrial Co., Ltd., model CR-90. -Antioxidants (F) ‧Antioxidant: hindered phenol series, pentaerythritol 4 [3-(3,5-di-tertiary butyl-4-hydroxyphenyl)propionate], manufactured by BASF Co., Ltd., model Irganox1010. -Dispersant (G) ‧Dispersant: Phosphate ester pigment dispersant, manufactured by BYK Japan Co., Ltd., model BYK-111 (liquid organic compound with two phosphate groups (phosphate ester compound with phosphate groups at both ends of the copolymer)), acid The price is 129 mg KOH/g, and the non-volatile content is 95%. -Other ingredients(H) ‧Melamine: Manufactured by Nissan Chemical Co., Ltd., micronized melamine. ‧Defoaming agent: manufactured by Shin-Etsu Silicone Co., Ltd., model KS-66.

<Evaluation test> (1) Preparation of test piece A glass epoxy copper-clad laminate having a copper foil with a thickness of 35 μm was prepared. This glass epoxy copper-clad laminate is etched to form conductor lines, thereby obtaining a printed circuit board. The photosensitive resin composition is coated on one entire surface of the printed circuit board by screen printing, thereby forming a coating film. The coating film was dried by heating at 80° C. for 20 minutes. The thickness of the coating film on the dried copper foil (dry coating film) was 20 μm. With the negative mask directly in contact with the surface of the dried coating film, ultraviolet rays were irradiated toward the negative mask to selectively expose the dried coating film at an exposure dose of 400 mJ/cm ² . Next, the negative mask was removed from the dried coating film, and the dried coating film was developed using a sodium carbonate aqueous solution with a concentration of 1% by mass at 30° C. for 60 seconds, thereby hardening the exposed components in the dried coating film. A portion remains on the printed circuit board as a solder resist layer. The solder resist layer was further heated at 150° C. for 60 minutes to be thermally hardened. In this way, a test piece with a solder resist layer was obtained. The following evaluation test was performed on this solder resist layer.

(2)Developability (development point) Development was performed for 90 seconds under the conditions of 30° C., 1 mass % sodium carbonate aqueous solution, and a spray pressure of 0.2 MPa, and the developability (development point) was evaluated based on the following evaluation criteria. A: The development point (the time required to develop the dry coating film) exceeds 0 seconds and is 20 seconds or less, and there is no part that cannot be developed. B: The development point exceeds 20 seconds and is less than 40 seconds, and there is no part that cannot be developed. C: The development point exceeds 40 seconds and is less than 60 seconds, and there is no part that cannot be developed. D: The development point exceeds 60 seconds, but there is no part that cannot be developed. E: There are parts that cannot be developed.

(3)Developability (drying allowable range) When the developability (drying allowable range) of the photosensitive resin composition is to be evaluated, a test piece for evaluation of the developability (drying allowable range) different from the test piece mentioned above is prepared. First, a wet coating film is formed on the printed circuit board using the same method as described above. Then, the wet coating film was heated at a heating temperature of 80° C. and a heating time of 20 minutes, 40 minutes, 60 minutes, and 80 minutes to form a dry coating film. The thickness of the dry coating films formed in this way was all 20 μm. The previously dried dry film was developed for 90 seconds using conditions of 30° C., 1 mass % sodium carbonate aqueous solution, and a spray pressure of 0.2 MPa. The coating film after the development treatment was observed, and the developability (drying allowable range) was evaluated based on the following evaluation criteria. A: The coating film dried with a heating temperature of 80°C and a heating time of 80 minutes can be developed. B: Under the condition of a heating temperature of 80° C., the coating film dried under the conditions of the heating time of 60 minutes can be developed, but development residue was confirmed in the coating film dried under the conditions of the heating time of 80 minutes. C: Under the condition of a heating temperature of 80°C, the coating film dried under the conditions of the heating time of 40 minutes can be developed, but the development residue was confirmed in the coating film dried under the conditions of the heating time of 60 minutes. D: Under the condition of a heating temperature of 80° C., the coating film dried under the conditions of a heating time of 20 minutes can be developed, but a development residue was observed in the coating film dried under the conditions of a heating time of 40 minutes. E: Development residue was confirmed in the coating film dried under the conditions of a heating temperature of 80° C. and a heating time of 20 minutes.

Deep hardenability (dam residue evaluation) Prepare a printed circuit board with copper conductor lines. The line width/line spacing of the copper conductor lines are 0.2mm/0.3mm and the thickness is 40 μm. In addition, a negative mask having a mask pattern for forming solder dams with widths of 30 μm, 40 μm, 50 μm, and 60 μm was used. Except for using these printed circuit boards and negative masks, the same conditions as when producing the aforementioned test pieces were used to form a solder barrier with a thickness of 60 μm on the printed circuit boards. A cellophane adhesive tape peeling test was performed on this solder barrier, and the minimum width of the solder barrier remaining on the printed wiring board without being peeled off was investigated, and the deep hardenability was evaluated based on the following evaluation criteria. A: The minimum width of the residual solder barrier is 30μm. B: The minimum width of the residual solder barrier is 40μm. C: The minimum width of the residual solder barrier is 50μm. D: The minimum width of the residual solder barrier is 60μm. E: No barrier weld remains.

(5)Reflectivity For the test piece immediately after production, a CIE table indicating the visual reflectance of the solder resist layer on the copper foil in the test piece was measured using a spectrophotometer (model CM-600d) manufactured by Konica Minolta Co., Ltd. Y value in the formula, and then evaluate the reflectance based on the following evaluation criteria. In Table 1, evaluations (A to E) are shown and the reflectance values are shown in parentheses. A: The Y value is above 85. B: Y value is above 80 and below 85. C: Y value is 75 or more and less than 80. D: Y value is above 70 and below 75. E: Y value is less than 70.

(6)Appearance Observe the coating surface of the solder resist layer on the copper foil in the test piece. In addition, "GLOSS CHECKER" manufactured by Horiba Manufacturing Co., Ltd. was used to measure the specular glossiness of the surface of the coating film at an incident angle of 60° based on Japanese Industrial Standard JIS-Z8741, and the appearance was evaluated based on the following evaluation criteria. In Table 1, evaluations (A to E) are shown and the gloss values are shown in parentheses. A: No lines are produced on the surface of the coating film, and the gloss value is 80 or above. B: No lines are formed on the surface of the coating film, and the gloss value is 75 or more but less than 80. C: No lines are formed on the surface of the coating film, and the gloss value is 70 or more but less than 75. D: No lines are produced on the surface of the coating film but less than 70. E: Textures appear on the surface of the coating film.

(7) Heat-resistant yellowing For the test piece immediately after production, a spectrophotometer (model CM-600d) manufactured by Konica Minolta Co., Ltd. was used to measure the L*a*b* color system of the solder resist layer in the test piece. b* value. Next, the test piece was heat-treated at 250° C. for 5 minutes, and then the b* value of the solder resist layer was measured again. The value (Δb*) obtained by subtracting the b* value of the solder resist layer before heat treatment from the b* value of the solder resist layer after heat treatment was calculated, and based on the result, the heat yellowing resistance was evaluated according to the following evaluation criteria. A: Δb* value is less than 1.5. B: Δb* value is more than 1.5 and less than 2.0. C: Δb* value is 2.0 or more and less than 2.5. D: Δb* value is more than 2.5 and less than 3.0. E: Δb* value is 3.0 or more.

(8)Storage stability The photosensitive resin composition was stored in a refrigerator at 4°C for 3 days, 7 days, 10 days and 14 days. Next, the photosensitive resin composition was applied to a glass plate with a film thickness of 20 μm, the coating film was visually observed, and the storage stability was evaluated based on the following evaluation criteria. A: No particles (fine particles) were found in the coating film of the photosensitive resin composition stored at 4° C. for 14 days. B: No particles (fine particles) were found in the coating film of the photosensitive resin composition after being stored at 4°C for 10 days, but in the coating film of the photosensitive resin composition after being stored at 4°C for 14 days Particles (particles) are found. C: No particles (fine particles) were found in the coating film of the photosensitive resin composition after being stored at 4°C for 7 days, but in the coating film of the photosensitive resin composition after being stored at 4°C for 10 days Particles (particles) are found. D: No particles (fine particles) were found in the coating film of the photosensitive resin composition after being stored at 4°C for 3 days, but in the coating film of the photosensitive resin composition after being stored at 4°C for 7 days Particles (particles) are found. E: Particles (fine particles) were found in the coating film of the photosensitive resin composition stored at 4° C. for 3 days.

[Table 1] The results in Table 1 show that the photosensitive resin compositions of Examples 1 to 14 can improve the developability and deep curability, and can also improve the appearance and appearance of the solder resist layer formed of the photosensitive resin composition. Reflectivity increased. On the other hand, it was also shown that the photosensitive resin compositions of Comparative Example 1 and Comparative Example 2, in which the carboxyl group-containing resin does not contain an oligomer part, have poor deep curability and the weight average molecular weight of the carboxyl group-containing resin is outside a specific range. The photosensitive resin compositions of Comparative Examples 3 and 4 had poor deep hardening properties and poor appearance of the solder resist layer.

(Summary) As can be seen from the above, the photosensitive resin composition of the first aspect of the present invention contains a carboxyl group-containing resin (A), a photopolymerization initiator (B), a photopolymerizable compound (C), an epoxy resin (D), and Titanium oxide(E). The carboxyl group-containing resin (A) has a carboxyl group-containing residue and an ethylenically unsaturated group located in a side chain, and contains a vinyl polymer with a weight average molecular weight of 10,000 or more and 100,000 or less, and the carboxyl group-containing resin (A) contains a vinyl polymer with a molecular weight of 450 The oligomer fraction above and below 1000. The proportion of titanium oxide (E) is 20 parts by mass or more relative to 100 parts by mass of the resin (A).

According to the first aspect, in addition to the fact that the proportion of titanium oxide (E) is not less than the aforementioned value and the Mw of the carboxyl group-containing resin (A) is within the aforementioned range, the carboxyl group-containing resin (A) contains a molecular weight of not less than 450 but not more than 1,000. In the oligomer part, the dispersibility of titanium oxide (E) will be further improved, and the reflectivity and gloss of the solder resist layer will be improved. In addition, properties such as hardenability in the solder resist layer will be further homogenized, thermal hardenability will become more uniform, and the development point will become shorter. In addition, the allowable range of drying time will become wider and developability will be improved. Furthermore, the photohardenability in the solder resist layer becomes more uniform, and the balance between surface hardening and deep hardening becomes good, thereby suppressing the generation of lines in the solder resist layer and improving the appearance. In this way, even if the photosensitive resin composition contains titanium oxide, the developability and deep hardening properties can be improved, and the appearance and reflectance of the solder resist layer can be improved.

The photosensitive resin composition of the second aspect is the photosensitive resin composition of the first aspect, wherein the ratio of the area of the oligomer part to 100% of the total area of the carboxyl group-containing resin (A) is 0.1% or more and 3% or less. Area is measured by gel transmission tomography using a differential refractive index detector.

According to the second aspect, the deep curability of the photosensitive resin composition and the heat yellowing resistance of the solder resist layer can be further improved.

The photosensitive resin composition of a third aspect is the first or second aspect, wherein at least part of the carboxyl group-containing resin (A) is a product of a polymerization reaction using a chain transfer agent.

According to the third aspect, the Mw of the obtained polymer can be reduced, and as a result, the proportion of the oligomer part in the carboxyl group-containing resin (A) can be increased.

A fourth aspect of the photosensitive resin composition is the third aspect, wherein the chain transfer agent is α-methylstyrene dimer.

According to the fourth aspect, by using an unsaturated hydrocarbon compound as a chain transfer agent, an ethylenically unsaturated group can be introduced into the carboxyl group-containing resin (A) and the terminal end of the oligomer contained in the carboxyl group-containing resin (A).

The photosensitive resin composition of a fifth aspect further contains an antioxidant (F) in any one of the first to fourth aspects.

According to the fifth aspect, the heat yellowing resistance of the solder resist layer can be further improved.

A sixth aspect is the photosensitive resin composition of the fifth aspect, wherein the antioxidant (F) contains a hindered phenol antioxidant.

According to the sixth aspect, the heat yellowing resistance of the solder resist layer can be further improved.

The photosensitive resin composition of a seventh aspect further contains a dispersant (G) in any one of the first to sixth aspects.

According to the seventh aspect, the dispersibility of particles in the photosensitive resin composition can be further improved.

An eighth aspect is the photosensitive resin composition according to the seventh aspect, wherein the dispersant (G) has a phosphate group.

According to the eighth aspect, the dispersibility of titanium oxide (E) in the photosensitive resin composition can be further improved, and the developability, deep hardening property, and appearance of the solder resist layer of the photosensitive resin composition can be further improved.

A ninth aspect of the photosensitive resin composition is any one of the first to eighth aspects, wherein the photopolymerization initiator (B) contains a hydroxyphosphine oxide-based photopolymerization initiator.

According to the ninth aspect, the developability and deep curability of the photosensitive resin composition can be further improved.

A tenth aspect of the photosensitive resin composition is the ninth aspect, wherein the photopolymerization initiator (B) further contains an α-hydroxyalkyl phenyl ketone-based photopolymerization initiator.

According to the tenth aspect, the developability and deep hardenability of the photosensitive resin composition can be further improved, and the surface hardenability can be improved. Furthermore, the solubility of the photopolymerization initiator can be improved, so that the photosensitive resin composition can be The storage stability of the object is further improved.

An eleventh aspect provides a photosensitive resin composition in any one of the first to tenth aspects, wherein the photopolymerizable compound (C) contains a trifunctional (meth)acrylate.

According to the eleventh aspect, a more appropriate cross-linked structure can be formed by exposure, and as a result, the developability and deep hardening properties of the photosensitive resin composition and the appearance of the solder resist layer can be further improved.

A twelfth aspect provides a photosensitive resin composition in any one of the first to eleventh aspects, wherein the epoxy resin (D) contains a crystalline epoxy resin.

According to the twelfth aspect, the developability and deep curability of the photosensitive resin composition can be further improved.

A thirteenth aspect provides a photosensitive resin composition in any one of the first to twelfth aspects, wherein the titanium oxide (E) contains rutile titanium oxide.

According to the thirteenth aspect, the heat resistance of the photosensitive resin composition can be further improved, and as a result, the heat resistance of the solder resist layer to yellowing can be further improved.

The dry film of the fourteenth aspect contains the photosensitive resin composition in any one of the first to thirteenth aspects.

According to the fourteenth aspect, the dry film can improve developability and deep hardening properties, and the solder resist layer obtained by hardening the dry film can improve the appearance and reflectivity. Therefore, the dry film can be suitably used as an electrically insulating material for a printed wiring board, and is particularly suitably used for forming electrically insulating layers such as a solder resist layer, a plating resist layer, an etching resist layer, and an interlayer insulating layer.

The solder resist of the fifteenth aspect contains a cured product of the photosensitive resin composition in any one of the first to thirteenth aspects.

According to the fifteenth aspect, the solder resist layer can improve appearance and reflectivity.

A printed circuit board according to a sixteenth aspect is provided with a solder resist layer containing a cured product of the photosensitive resin composition in any one of the first to thirteenth aspects.

According to the sixteenth aspect, the appearance and reflectivity of the solder resist layer can be improved, thereby improving the performance of the printed circuit board.

without

without

Domestic storage information (please note in order of storage institution, date and number) without Overseas storage information (please note in order of storage country, institution, date, and number) without

Claims (16)

A photosensitive resin composition, which contains carboxyl-containing resin (A), photopolymerization initiator (B), photopolymerizable compound (C), epoxy resin (D) and titanium oxide (E); the aforementioned carboxyl-containing resin (A) has a carboxyl group-containing residue and an ethylenically unsaturated group located in the side chain, and contains a vinyl polymer with a weight average molecular weight of 10,000 or more and 100,000 or less, and the aforementioned carboxyl group-containing resin (A) contains a molecular weight of 450 or more and The oligomer portion below 1000; the ratio of the area of the aforementioned oligomer portion to 100% of the total area of the aforementioned carboxyl group-containing resin (A) measured by gel transmission chromatography using a differential refractive index detector , is 0.1% or more and 9% or less; and the proportion of the aforementioned titanium oxide (E) is 20 parts by mass or more relative to 100 parts by mass of the aforementioned carboxyl group-containing resin (A). The photosensitive resin composition according to claim 1, wherein the area of the oligomer portion measured by gel transmission chromatography using a differential refractive index detector is relative to the area of the carboxyl-containing resin (A ) of the total area is 0.1% or more and 3% or less. The photosensitive resin composition according to claim 1 or 2, wherein at least part of the carboxyl group-containing resin (A) is a product of a polymerization reaction using a chain transfer agent. The photosensitive resin composition according to claim 3, wherein the chain transfer agent is α-methylstyrene dimer. The photosensitive resin composition according to claim 1 or 2, further containing an antioxidant (F). The photosensitive resin composition according to claim 5, wherein the antioxidant (F) contains a hindered phenol antioxidant. The photosensitive resin composition according to claim 1 or 2, further containing a dispersant (G). The photosensitive resin composition according to claim 7, wherein the dispersant (G) has a phosphate group. The photosensitive resin composition according to claim 1 or 2, wherein the photopolymerization initiator (B) contains a hydroxyphosphine oxide-based photopolymerization initiator. The photosensitive resin composition according to claim 9, wherein the photopolymerization initiator (B) further contains an α-hydroxyalkyl phenyl ketone photopolymerization initiator. The photosensitive resin composition according to claim 1 or 2, wherein the photopolymerizable compound (C) contains a trifunctional (meth)acrylate. The photosensitive resin composition according to claim 1 or 2, wherein the epoxy resin (D) contains a crystalline epoxy resin. The photosensitive resin composition according to claim 1 or 2, wherein the titanium oxide (E) contains rutile titanium oxide. A dry film comprising the photosensitive resin composition described in any one of claims 1 to 13. A solder resist containing a cured product of the photosensitive resin composition according to any one of claims 1 to 13. A printed circuit board is provided with a solder resist layer. The flux layer contains a cured product of the photosensitive resin composition according to any one of claims 1 to 13.