JP2023183285A - Photosensitive resin composition, photocured product of photosensitive resin composition, and printed wiring board with photocured film of photosensitive resin composition - Google Patents

Abstract

To provide a photosensitive resin composition that yields a photocured product with superior resolution and also exhibits high hiding power.SOLUTION: A photosensitive resin composition includes (A) a photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, (E) a filler, and (F) a colorant, where the (F) colorant includes (F1) zirconium nitride.SELECTED DRAWING: None

Description

The present invention relates to a photosensitive resin composition having excellent resolution and high hiding power, and for example, when used as a solder resist for printed wiring boards, it can cope with fine pitch and miniaturization of electrodes. , relates to a photosensitive resin composition having high hiding power for printed wiring boards.

A printed wiring board is a member having a conductor circuit pattern formed on a substrate, and is used to mount electronic components on the soldering lands of the conductor circuit pattern. The circuit portion of the conductor circuit pattern excluding the soldering lands is covered with an insulating protective film (for example, a solder resist film). This prevents solder from adhering to unnecessary parts when soldering electronic components to printed wiring boards, and also prevents circuits (conductors) from being directly exposed to air and corroding due to oxidation and humidity. To prevent.

In addition, in recent years, with technological advances, there has been an increasing demand for miniaturization and weight reduction in the electronics field. Fine pitch, miniaturization, and high precision of conductor circuit patterns on wiring boards are required. Accordingly, there is a demand for insulating protective films with higher performance in terms of resolution. Further, the insulating protective film may be required to have high hiding power. In order to impart high hiding power to the insulating protective film, the insulating protective film is sometimes colored black or the like.

As a material for forming a black insulating protective film, a solder resist composition has been proposed in which the colorant added to the carboxyl group-containing resin is a black colorant and one or more colorants other than the black colorant. (Patent Document 1).

However, the black solder resist composition of Patent Document 1 preferably uses carbon black as a black colorant that imparts high hiding power. However, carbon black has a low light transmittance in the ultraviolet wavelength range, so it absorbs a lot of ultraviolet rays during exposure, making it difficult for ultraviolet rays to reach deep into the solder resist coating. Therefore, in Patent Document 1, the photocuring in the deep part of the solder resist coating film is not sufficient, and the dimension of the deep part of the solder resist coating film becomes too small after development, and the cured coating film peels off from the printed wiring board. There was room for improvement in the resolution of the protective film.

Japanese Patent Application Publication No. 2008-257045

In view of the above circumstances, an object of the present invention is to provide a photosensitive resin composition that can obtain a photocured product having excellent resolution and also has high hiding power.

The gist of the configuration of the present invention is as follows.
[1] (A) photosensitive resin, (B) photopolymerization initiator, (C) reactive diluent, (D) epoxy compound, (E) filler, and (F) colorant. Contains
A photosensitive resin composition in which the colorant (F) contains (F1) zirconium nitride.
[2] The photosensitive resin composition according to [1], wherein the 50 ppm dispersion of zirconium nitride (F1) has a transmittance of 18.0% or more for light at a wavelength of 365 nm.
[3] The photosensitive resin composition according to [1], wherein the 50 ppm dispersion of zirconium nitride (F1) has a transmittance of 25.0% or more for light at a wavelength of 365 nm.
[4] Any one of [1] to [3], wherein the ratio of the transmittance of the 50 ppm dispersion of zirconium nitride (F1) to the transmittance of light with a wavelength of 365 nm to the transmittance of light with a wavelength of 550 nm is 3.0 or more. 1. The photosensitive resin composition according to item 1.
[5] Any one of [1] to [3], wherein the ratio of the transmittance of the 50 ppm dispersion of zirconium nitride (F1) to the transmittance of light with a wavelength of 365 nm to the transmittance of light with a wavelength of 550 nm is 4.5 or more. 1. The photosensitive resin composition according to item 1.
[6] Any one of [1] to [3] containing 4.0 parts by mass or more and 20 parts by mass or less of zirconium nitride (F1) based on 100 parts by mass (solid content) of the photosensitive resin (A). 1. The photosensitive resin composition according to item 1.
[7] Any one of [1] to [3] containing 7.0 parts by mass or more and 15 parts by mass or less of the (F1) zirconium nitride based on 100 parts by mass (solid content) of the photosensitive resin (A). 1. The photosensitive resin composition according to item 1.
[8] The photosensitive resin composition according to any one of [1] to [3], wherein the L value of the zirconium nitride (F1) is 8 or more and 18 or less.
[9] The photosensitive resin composition according to any one of [1] to [3], which does not contain carbon black.
[10] The photopolymerization initiator (B) contains at least one selected from the group consisting of α-aminoalkylphenone photopolymerization initiators and oxime ester photopolymerization initiators [1] to [3] The photosensitive resin composition according to any one of the above.
[11] The photosensitive resin (A) is radically polymerizable by reacting a radically polymerizable unsaturated monocarboxylic acid with at least a portion of the epoxy groups of a polyfunctional epoxy resin having two or more epoxy groups in one molecule. A polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin having a structure obtained by obtaining an unsaturated monocarboxylated epoxy resin and reacting the generated hydroxyl groups with a polybasic acid and/or a polybasic acid anhydride. and the epoxy compound (D) contains an epoxy resin of the same type as the polyfunctional epoxy resin forming the skeleton of the polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin [1] to [ 3]. The photosensitive resin composition according to any one of [3].
[12] A photocured product of the photosensitive resin composition according to any one of [1] to [3].
[13] A printed wiring board having a photocured film of the photosensitive resin composition according to any one of [1] to [3].

(F1) The light transmittance of the 50 ppm dispersion of zirconium nitride is the light transmittance measured by injecting the dispersion into a measurement cell with a cell thickness of 10 mm.

According to the aspect of the photosensitive resin composition of the present invention, the coloring agent (F) contains (F1) zirconium nitride, and since zirconium nitride has a high transmittance of light in the ultraviolet wavelength range, Photocuring progresses sufficiently deep into the photosensitive resin composition, resulting in excellent resolution. Zirconium nitride has low light transmittance in the visible wavelength range, so it is a cured product with hiding power. can be obtained. In addition, since the (F) colorant contains (F1) zirconium nitride, it is possible to prevent the width dimension of the deep part of the coating film from decreasing after development, so the width dimension of the deep part of the coating film is equal to the width dimension of the surface layer part of the coating film. This will improve the dimensional accuracy of the cured coating.

According to an aspect of the photosensitive resin composition of the present invention, the transmittance of the 50 ppm dispersion of (F1) zirconium nitride to light at a wavelength of 365 nm is 18.0% or more, so that the coated photosensitive resin Photocuring progresses more reliably to the deep part of the composition, and a cured product having better resolution can be obtained.

According to an aspect of the photosensitive resin composition of the present invention, the transmittance of the 50 ppm dispersion of (F1) zirconium nitride to light at a wavelength of 365 nm is 25.0% or more, so that the coated photosensitive resin The photocurability in the deep part of the composition is further improved, and a cured product having even better resolution can be obtained.

According to an aspect of the photosensitive resin composition of the present invention, the ratio of the transmittance of the 50 ppm dispersion of zirconium nitride (F1) to the transmittance of light with a wavelength of 365 nm to the transmittance of light with a wavelength of 550 nm is 3.0 or more. By doing so, excellent resolution can be reliably obtained.

According to an aspect of the photosensitive resin composition of the present invention, the ratio of the transmittance of the 50 ppm dispersion of zirconium nitride (F1) to the transmittance of light with a wavelength of 365 nm to the transmittance of light with a wavelength of 550 nm is 4.5 or more. This further improves resolution.

According to an aspect of the photosensitive resin composition of the present invention, (F1) zirconium nitride is contained in 4.0 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass (solid content) of (A) photosensitive resin. As a result, excellent resolution and high hiding power can be improved in a well-balanced manner.

According to an aspect of the photosensitive resin composition of the present invention, (F1) zirconium nitride is contained in 7.0 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass (solid content) of (A) photosensitive resin. Accordingly, it is possible to further improve the hiding power while improving excellent resolution and high hiding power in a well-balanced manner.

According to an embodiment of the photosensitive resin composition of the present invention, the photopolymerization initiator (B) is at least one selected from the group consisting of an α-aminoalkylphenone photopolymerization initiator and an oxime ester photopolymerization initiator. By including the seeds, the photocurability of the photosensitive resin composition is improved, and excellent hardness and durability can be imparted to the cured product.

According to an aspect of the photosensitive resin composition of the present invention, (A) the photosensitive resin has radical polymerizable unsaturation in at least a portion of the epoxy groups of the polyfunctional epoxy resin having two or more epoxy groups in one molecule. A polybasic acid-modified radical having a structure obtained by reacting a monocarboxylic acid to obtain a radically polymerizable unsaturated monocarboxylated epoxy resin and reacting the generated hydroxyl group with a polybasic acid and/or a polybasic acid anhydride. A polymerizable unsaturated monocarboxylated epoxy resin, in which the epoxy compound (D) is the same type of epoxy as the polyfunctional epoxy resin forming the skeleton of the polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin. By containing the resin, the strength of the cured product of the photosensitive resin composition can be improved.

Next, each component of the photosensitive resin composition of the present invention will be explained in detail. The photosensitive resin composition of the present invention comprises (A) a photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, (E) a filler, ( F) a colorant, and the colorant (F) contains (F1) zirconium nitride.

In the photosensitive resin composition of the present invention, since the colorant (F) contains (F1) zirconium nitride, zirconium nitride has high transmittance for light in the ultraviolet wavelength range and light in the visible light wavelength range. Since the transmittance of the photosensitive resin composition is low, photocuring proceeds sufficiently deep into the coated photosensitive resin composition, and a cured product having excellent resolution and high hiding power can be obtained. In addition, since the (F) colorant contains (F1) zirconium nitride, it is possible to prevent the width dimension of the deep part of the coating film from decreasing after development, so the width dimension of the deep part of the coating film is equal to the width dimension of the surface layer part of the coating film. This will improve the dimensional accuracy of the cured coating.

<(A) Photosensitive resin>
The photosensitive resin which is the component (A) is the base resin of the photosensitive resin composition. The structure of the photosensitive resin is not particularly limited, and examples include carboxyl group-containing photosensitive resins having one or more photosensitive unsaturated double bonds and a free carboxyl group. As the carboxyl group-containing photosensitive resin, for example, (A1) a polyfunctional epoxy resin having two or more epoxy groups in one molecule, at least a portion of the epoxy groups is reacted with a radically polymerizable unsaturated monocarboxylic acid to form a radical. A polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy having a structure obtained by obtaining a polymerizable unsaturated monocarboxylated epoxy resin and reacting the generated hydroxyl group with a polybasic acid and/or a polybasic acid anhydride. resin (A1 resin), (A2) a polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin (A2 resin) into which a radically polymerizable unsaturated group is further introduced, (A3) an epoxy group in one molecule. A radically polymerizable unsaturated monocarboxylic acid is reacted with at least a portion of the epoxy groups of a polyfunctional epoxy resin having two or more epoxy groups to obtain a radically polymerizable unsaturated monocarboxylic oxidized epoxy resin, and a polyisocyanate compound is added to the generated hydroxyl groups. An acid-modified urethanized unsaturated monocarboxylated epoxy resin (A3 resin) having a structure obtained by addition reaction and addition reaction of a compound having a hydroxyl group and a carboxyl group to the isocyanate group of the polyisocyanate compound subjected to the addition reaction. Can be mentioned.

(A1) Polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin Polyfunctional epoxy resin The epoxy equivalent of the polyfunctional epoxy resin is not particularly limited, and for example, the upper limit thereof is preferably 3000 g/eq and 2000 g/eq. eq is more preferred, 1000 g/eq is even more preferred, and 500 g/eq is particularly preferred. On the other hand, the lower limit of the epoxy equivalent of the polyfunctional epoxy resin is preferably 100 g/eq, particularly preferably 200 g/eq. The chemical structure of the polyfunctional epoxy resin is not particularly limited, and examples of the polyfunctional epoxy resin include biphenylaralkyl epoxy resin, phenylaralkyl epoxy resin, biphenyl epoxy resin, naphthalene epoxy resin, and dicyclopentadiene epoxy resin. Resin, rubber modified epoxy resin such as silicone modified epoxy resin, ε-caprolactone modified epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin such as ortho-cresol novolak type, bisphenol novolac type epoxy resin , cycloaliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol modified novolac type epoxy resin, polyfunctional modified novolac type epoxy resin, etc. be able to. These polyfunctional epoxy resins may be used alone or in combination of two or more.

Radically polymerizable unsaturated monocarboxylic acid The carboxyl group of the radically polymerizable unsaturated monocarboxylic acid reacts with the epoxy group of the polyfunctional epoxy resin to form an ester bond, resulting in a photosensitive unsaturated double Bonds are introduced to impart photosensitive properties to the multifunctional epoxy resin backbone. Examples of radically polymerizable unsaturated monocarboxylic acids include acrylic acid, methacrylic acid (acrylic acid and/or methacrylic acid is sometimes referred to as "(meth)acrylic acid"), crotonic acid, tiglic acid, angelic acid, Cinnamic acid and the like can be mentioned. Among these, (meth)acrylic acid is preferred in terms of reactivity, ease of availability, and ease of handling. These radically polymerizable unsaturated monocarboxylic acids may be used alone or in combination of two or more.

The method of reacting the radically polymerizable unsaturated monocarboxylic acid with the polyfunctional epoxy resin is not particularly limited. An example is a method of stirring while heating in an organic solvent).

Polybasic acid and/or polybasic acid anhydride The polybasic acid and/or polybasic acid anhydride reacts with the hydroxyl groups of the radically polymerizable unsaturated monocarboxylated epoxy resin to form free carboxyl groups in the photosensitive resin. groups can be introduced to obtain A1 resin. The polybasic acid and/or polybasic acid anhydride is not particularly limited, and either saturated or unsaturated polybasic acids can be used. Examples of polybasic acids include malonic acid, succinic acid, maleic acid, itaconic acid, adipic acid, citric acid, phthalic acid, terephthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, Tetrahydrophthalic acids such as 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydro Phthalic acid, hexahydrophthalic acids such as 3-ethylhexahydrophthalic acid and 4-ethylhexahydrophthalic acid, bifunctional carboxylic acids such as diglycolic acid, trifunctional carboxylic acids such as trimellitic acid, and pyromellitic acid. Examples include tetrafunctional carboxylic acids such as. Examples of the polybasic acid anhydride include the anhydrides of the polybasic acids described above. These polybasic acids and polybasic acid anhydrides may be used alone or in combination of two or more.

The method of reacting a radically polymerizable unsaturated monocarboxylated epoxy resin with a polybasic acid and/or a polybasic acid anhydride is not particularly limited. For example, the method of reacting a radically polymerizable unsaturated monocarboxylated epoxy resin with a polybasic acid and A method of stirring the mixture and/or polybasic acid anhydride in an appropriate dispersion medium (for example, an inert organic solvent) while heating the mixture can be mentioned.

(A2) A polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin into which a radically polymerizable unsaturated group has been further introduced. A2 resin is a carboxyl epoxy resin of the above polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin. It is a carboxyl group-containing photosensitive resin having a chemical structure in which a part of the group is further reacted with a compound having one or more radically polymerizable unsaturated groups and an epoxy group (for example, a glycidyl compound). In the carboxyl group-containing photosensitive resin obtained by further reacting a compound having a radically polymerizable unsaturated group and an epoxy group, a radically polymerizable unsaturated group is added to the side chain of the polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin. It has a chemical structure that has been further introduced. Therefore, a carboxyl group-containing photosensitive resin having a chemical structure obtained by reacting a compound having a radically polymerizable unsaturated group and an epoxy group is better than a polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin (A1 resin). It also has excellent photopolymerization reactivity and further improves photosensitivity.

Examples of compounds having a radically polymerizable unsaturated group and an epoxy group include glycidyl acrylate, glycidyl methacrylate (acrylate and/or methacrylate are sometimes referred to as "(meth)acrylate"), allyl glycidyl ether, and pentaerythritol trichloride. Examples include (meth)acrylate monoglycidyl ether. These compounds having a radically polymerizable unsaturated group and an epoxy group may be used alone or in combination of two or more. The method of reacting a polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin with a compound having a radically polymerizable unsaturated group and an epoxy group is not particularly limited. Examples include a method in which a monocarboxylated epoxy resin and a compound having a radically polymerizable unsaturated group and an epoxy group are stirred while being heated in a suitable dispersion medium (for example, an inert organic solvent).

(A3) Acid-modified urethanized unsaturated monocarboxylated epoxy resin Polyfunctional epoxy resin The polyfunctional epoxy resin is not particularly limited, but is the same as the polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin (A1 resin). For example, rubber-modified epoxy resins such as biphenylaralkyl-type epoxy resins, phenylaralkyl-type epoxy resins, biphenyl-type epoxy resins, naphthalene-type epoxy resins, dicyclopentadiene-type epoxy resins, silicone-modified epoxy resins, ε-caprolactone-modified epoxy resins, Bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin such as ortho-cresol novolak type, bisphenol novolac type epoxy resin, cycloaliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidyl amine type Examples include polyfunctional epoxy resins, heterocyclic polyfunctional epoxy resins, bisphenol-modified novolac epoxy resins, and polyfunctional modified novolak epoxy resins. These polyfunctional epoxy resins may be used alone or in combination of two or more.

Radically polymerizable unsaturated monocarboxylic acid The radically polymerizable unsaturated monocarboxylic acid is not particularly limited, but as with the polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin (A1 resin), for example, (meth) Examples include acrylic acid, crotonic acid, tiglic acid, angelic acid, and cinnamic acid. Among these, (meth)acrylic acid is preferred in terms of reactivity, ease of availability, and ease of handling. These radically polymerizable unsaturated monocarboxylic acids may be used alone or in combination of two or more.

Polyisocyanate Compound The polyisocyanate compound is not particularly limited, and includes, for example, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), methylene biscyclohexyl isocyanate, trimethylhexamethyl diisocyanate, hexane diisocyanate, Examples include diisocyanate compounds such as hexamethylamine diisocyanate, toluene diisocyanate, tolylene diisocyanate, isophorone diisocyanate, 1,2-diphenylethane diisocyanate, 1,3-diphenylpropane diisocyanate, diphenylmethane diisocyanate, and dicyclohexylmethyl diisocyanate. These polyisocyanate compounds may be used alone or in combination of two or more.

Compounds having a hydroxyl group and a carboxyl group Compounds having a hydroxyl group and a carboxyl group are not particularly limited. Mention may be made of alkanol alkanoic acids. These compounds may be used alone or in combination of two or more.

A1 resin, A2 resin, and A3 resin may be used alone or in combination of two or more.

The acid value of the carboxyl group-containing photosensitive resin is not particularly limited, but for example, the lower limit thereof is preferably 30 mgKOH/g from the viewpoint of reliably imparting alkali developability to the photocured product of the photosensitive resin composition. 40 mgKOH/g is particularly preferred. On the other hand, the upper limit of the acid value of the carboxyl group-containing photosensitive resin is preferably 200 mgKOH/g from the viewpoint of reliably preventing dissolution of the exposed area (photocured area) by an alkaline developer, and the insulation reliability of the photocured product. From the viewpoint of reliably improving properties, 150 mgKOH/g is particularly preferable.

The carboxyl group-containing photosensitive resin may be prepared in the reaction step using the above components, or a commercially available carboxyl group-containing photosensitive resin may be used. Examples of commercially available carboxyl group-containing photosensitive resins include "Lipoxy SP-4621", "Lipoxy SP-4785L" (Showa Denko K.K.), "ZAR-2000", "ZFR-1122", and "ZFR". -1887'', ``FLX-2089'', ``ZCR-1569H'', ``ZCR-1601H'' (Nippon Kayaku Co., Ltd.), ``Cyclomer P (ACA) Z-250'' (Daicel Co., Ltd.), etc. be able to.

Further, when the photosensitive resin composition is not subjected to alkaline development treatment, a photosensitive resin having no carboxyl group may be used.

Examples of photosensitive resins without carboxyl groups include (A4) polymers of monomers consisting of esters of radically polymerizable unsaturated monocarboxylic acids such as (meth)acrylate (A4 resin), (A5) (meth) A copolymer (A5 resin) consisting of an ester of a radically polymerizable unsaturated monocarboxylic acid such as acrylate and another polymerizable monomer, an ester of a radically polymerizable unsaturated monocarboxylic acid such as (A6) (meth)acrylate, A radically polymerizable unsaturated monocarboxylic acid such as (meth)acrylic acid is reacted with at least a portion of the epoxy group of a copolymer of a compound having one or more radically polymerizable unsaturated groups and an epoxy group. (A6 resin), (A7) at least a part of the carboxyl group of a polymer of radically polymerizable unsaturated monocarboxylic acid such as (meth)acrylic acid, or radically polymerizable unsaturated monocarboxylic acid such as (meth)acrylic acid At least a portion of the carboxyl groups of the copolymer obtained by reacting an acid with an ester of a radically polymerizable unsaturated monocarboxylic acid such as (meth)acrylate has one or more radically polymerizable unsaturated groups and an epoxy group. Resin (A7 resin) obtained by reacting a compound having Examples include radically polymerizable unsaturated monocarboxylated epoxy resin (A8 resin).

In order to prepare the above-mentioned photosensitive resin having no carboxyl group, the above-mentioned radically polymerizable unsaturated monocarboxylic acid and the above-mentioned one or more radically polymerizable unsaturated groups and epoxy It is possible to use the same compounds as those having groups. In addition, as the radically polymerizable unsaturated monocarboxylated epoxy resin such as epoxy (meth)acrylate, for example, the radically polymerizable unsaturated monocarboxylate epoxy resin such as epoxy (meth)acrylate obtained in the process of preparing the above-mentioned carboxyl group-containing photosensitive resin. Examples include monocarboxylic oxidized epoxy resins.

A4 resin, A5 resin, A6 resin, A7 resin, and A8 resin may be used alone or in combination of two or more.

The mass average molecular weight of the photosensitive resin is not particularly limited and can be selected as appropriate depending on the conditions of use. It is preferably 7,000, more preferably 8,000. On the other hand, the upper limit of the mass average molecular weight of the photosensitive resin is preferably 200,000, more preferably 100,000, and particularly preferably 50,000, from the viewpoint of contributing to improving alkali developability. In addition, the above-mentioned "mass average molecular weight" means a mass average molecular weight measured at room temperature using gel permeation chromatography (GPC) and calculated in terms of polystyrene.

<(B) Photopolymerization initiator>
The photopolymerization initiator is not particularly limited as long as it is commonly used. Specifically, for example, 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone 1-[9-ethyl-6-(2-methylbenzoyl)- 9H-carbazol-3-yl]-1-(0-acetyloxime), (Z) -(9-ethyl-6-nitro-9H-carbazol-3-yl)(4-((1-methoxypropane-2 -yl)oxy) -2-methylphenyl)methanone O-acetyloxime, 2-(acetyloxyiminomethyl)thioxanthene-9-one, 1,8-octanedione, 1,8-bis[9-ethyl-6 -Nitro-9H-carbazol-3-yl]-, 1,8-bis(O-acetyloxime), 1,8-octanedione, 1,8-bis[9-(2-ethylhexyl)-6-nitro- 9H-carbazol-3-yl]-,1,8-bis(O-acetyloxime), (Z)-(9-ethyl-6-nitro-9H-carbazol-3-yl)(4-((1- Examples include oxime ester compounds such as methoxypropan-2-yl)oxy)-2-methylphenyl)methanone and O-acetyloxime. Also, 1-(4-morpholinophenyl)-2-(dimethylamino)-2-(4-methylbenzyl)-1-butanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone Examples include α-aminoalkylphenone photopolymerization initiators such as -1,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

In addition, photopolymerization initiators other than those mentioned above include, for example, acetophenone type such as acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2,4, 6-Trimethylbenzoyldiphenylphosphine oxide, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1 -Hydroxycyclohexylphenylketone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone , 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal , acetophenone dimethyl ketal, P-dimethylaminobenzoic acid ethyl ester, and the like. These photopolymerization initiators may be used alone or in combination of two or more.

Among these, α-aminoalkylphenone-based photopolymerization initiators, oxime ester-based photopolymerization initiators, and oxime ester-based Photoinitiators are preferred.

The amount of the photopolymerization initiator is not particularly limited, and is preferably 0.5 parts by mass or more and 20 parts by mass or less, and 1.0 parts by mass or more, based on 100 parts by mass (solid content, same hereinafter) of the photosensitive resin. Particularly preferably 10 parts by mass or less.

<(C) Reactive diluent>
The reactive diluent is, for example, a photopolymerizable monomer, and is a compound having at least one polymerizable double bond per molecule, preferably two or more per molecule. The reactive diluent contributes to reinforcing photocuring of the photosensitive resin composition and imparting sufficient strength, heat resistance, acid resistance, alkali resistance, etc. to the cured product of the photosensitive resin composition.

Examples of the reactive diluent include monofunctional or Examples include monomers of polyfunctional (meth)acrylate compounds. Examples of monomers of (meth)acrylate compounds include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, diethylene glycol mono(meth)acrylate, 2-hydroxy-3- Monofunctional (meth)acrylate compounds such as phenoxypropyl (meth)acrylate; 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, Diethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, ethylene oxide modified phosphoric acid di(meth)acrylate, Allyl Bifunctional (meth)acrylate compounds such as cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate; trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate , trifunctional (meth)acrylate compounds such as propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate; ditrimethylolpropane tetra(meth)acrylate, propionic acid-modified dipentaerythritol penta(meth) Examples include tetrafunctional or higher functional (meth)acrylate compounds such as acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. These (meth)acrylate compounds may be used alone or in combination of two or more.

The amount of the reactive diluent is not particularly limited, but is preferably 5.0 parts by mass or more and 50 parts by mass or less, particularly preferably 15 parts by mass or more and 35 parts by mass or less, based on 100 parts by mass of the photosensitive resin.

<(D) Epoxy compound>
The epoxy compound is for increasing the crosslinking density of the cured product of the photosensitive resin composition and imparting sufficient hardness to the cured product. Examples of epoxy compounds include epoxy resins. Epoxy resins are not particularly limited, and include rubber-modified epoxy resins such as biphenylaralkyl epoxy resins, phenylaralkyl epoxy resins, biphenyl epoxy resins, naphthalene epoxy resins, dicyclopentadiene epoxy resins, and silicone-modified epoxy resins. Resin, ε-caprolactone modified epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin such as ortho-cresol novolac type, bisphenol novolac type epoxy resin, cycloaliphatic polyfunctional epoxy resin, glycidyl ester Examples include polyfunctional epoxy resins of type polyfunctional epoxy resins, polyfunctional epoxy resins of glycidylamine type, polyfunctional heterocyclic epoxy resins, polyfunctional epoxy resins of bisphenol modification, and polyfunctional modified novolac type epoxy resins. These epoxy compounds may be used alone or in combination of two or more.

When the photosensitive resin is the above-mentioned A1 resin, A2 resin, A3 resin, or A8 resin, the epoxy compound is A1 resin, A2 resin, etc., since the strength of the cured product of the photosensitive resin composition can be improved. It is preferable to contain an epoxy resin of the same type as the above polyfunctional epoxy resin forming the skeleton of the resin, A3 resin or A8 resin. That is, as the epoxy compound, the same type of epoxy resin as the polyfunctional epoxy resin used for preparing the photosensitive resin described above can be used. For example, the photosensitive resin is oxidized by radically polymerizable unsaturated monocarboxylic acid by reacting a radically polymerizable unsaturated monocarboxylic acid with at least a portion of the epoxy groups of a multifunctional epoxy resin having two or more epoxy groups in one molecule. It is a polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxidized epoxy resin (A1 resin) having a structure obtained by obtaining an epoxy resin and reacting the generated hydroxyl group with a polybasic acid and/or a polybasic acid anhydride. In this case, the epoxy compound of component (D) contains an epoxy resin of the same type as the polyfunctional epoxy resin forming the skeleton of the polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin (A1 resin). be able to.

The amount of the epoxy compound is not particularly limited, but is preferably 5.0 parts by mass or more and 50 parts by mass or less, particularly preferably 15 parts by mass or more and 35 parts by mass or less, based on 100 parts by mass of the photosensitive resin.

<(E) Filler>
The filler is a component that contributes to increasing the physical strength of the coating film of the photosensitive resin composition. Examples of fillers include inorganic fillers and organic fillers. Examples of the inorganic filler include talc, barium sulfate, silica, alumina, aluminum hydroxide, and mica. Examples of organic fillers include polymers such as urethane resins (polymer of isocyanate and polyol), acrylic resins, polyethylene, copolymers of styrene and butadiene such as styrene-butadiene rubber, and silicone resins such as silicone rubber. be able to.

The shape of the filler is not particularly limited, but is preferably particulate. The average particle diameter of the filler is not particularly limited, but from the viewpoint of uniform dispersibility in the photosensitive resin composition and coatability of the photosensitive resin composition, it is preferably 0.1 μm or more and 20 μm or less, and 0.5 μm or more and 10 μm or less. The following are particularly preferred.

The blending amount of the filler is not particularly limited, but is preferably 5.0 parts by mass or more and 50 parts by mass or less, particularly preferably 10 parts by mass or more and 30 parts by mass or less, based on 100 parts by mass of the photosensitive resin.

<(F) Colorant>
The photosensitive resin composition of the present invention contains (F1) zirconium nitride as a colorant. Zirconium nitride functions as a black colorant, and by containing zirconium nitride as a colorant, the photosensitive resin composition has a black color. Zirconium nitride has a high transmittance for light in the ultraviolet wavelength range of 300 nm to 400 nm, but has a low transmittance for light in the visible light wavelength range (wavelengths of about 400 nm to 800 nm). Therefore, in the coated photosensitive resin composition of the present invention, photocuring due to exposure treatment sufficiently progresses to the deep part of the coating film, resulting in a cured product having excellent resolution and high hiding power. . In addition, since the colorant contains zirconium nitride, it is possible to prevent the width dimension of the deep part of the coating film from decreasing after development, so the width dimension of the deep part of the coating film approaches the width dimension of the surface layer part of the coating film, and the width of the cured coating film increases. Improves dimensional accuracy.

Since the photosensitive resin composition of the present invention does not need to contain other black colorants such as carbon black, the transmittance of light in the wavelength range of 300 to 400 nm is improved, and the photosensitive resin composition can be used deep in the coating film. The photocurability up to 100% is reliably improved. Furthermore, since the photosensitive resin composition of the present invention does not need to contain carbon black, the insulating properties of the cured product are improved. From the above, it is preferable that the photosensitive resin composition of the present invention does not contain carbon black.

The transmittance of zirconium nitride for light at a wavelength of 365 nm is higher than the transmittance of carbon black for light at a wavelength of 365 nm. Light at a wavelength of 365 nm in a 50 ppm dispersion of zirconium nitride is used because photocuring can proceed more reliably deep into the applied photosensitive resin composition and a cured product with better resolution can be obtained. The transmittance (T ₃₆₅ ) of is preferably 18.0% or more, more preferably 20.0% or more, and the photocurability in the deep part of the coated photosensitive resin composition is further improved. The content is particularly preferably 25.0% or more, since it is possible to obtain a cured product with even better resolution. The upper limit of the transmittance (T ₃₆₅ ) of light at a wavelength of 365 nm in a 50 ppm dispersion of zirconium nitride is, for example, to prevent excessive photocuring due to the transmittance of light at a wavelength of 365 nm being too high, and to 35.0% is preferable from the viewpoint of preventing the coating film opening after treatment from becoming narrower than the setting and ensuring excellent dimensional accuracy.

Further, the ratio (T ₃₆₅ /T ₅₅₀ ) of the transmittance (T ₃₆₅ ) of the 50 ppm zirconium nitride dispersion to the light at the wavelength 365 nm (T ₅₅₀ ) of the 50 ppm zirconium nitride dispersion is as follows: From the standpoint of reliably obtaining excellent resolution, it is preferably 3.0 or more, more preferably 3.5 or more, and particularly preferably 4.5 or more from the standpoint of further improving resolution. The upper limit of the ratio (T ₃₆₅ /T ₅₅₀ ) of the transmittance of light at a wavelength of 365 nm (T ₃₆₅ ) to the transmittance of light at a wavelength of 550 nm (T ₅₅₀ ) of a 50 ppm dispersion of zirconium nitride is, for example, This prevents the preferential progress of photocuring on the surface of the coating film and insufficient curing of the bottom of the coating film due to the rate ratio (T ₃₆₅ /T ₅₅₀ ) being too high, thereby preventing the openings of the coating film from becoming overhang-like. From the viewpoint of prevention, 7.0 is preferable.

The transmittance (T ₅₅₀ ) of the 50 ppm dispersion of zirconium nitride for light at a wavelength of 550 nm is preferably 8.0% or less, and 6.0% or less, from the viewpoint of obtaining a cured product with excellent hiding power. is particularly preferred.

The L value (lightness) of zirconium nitride is, for example, 8 or more and 18 or less, preferably 8 or more and 16 or less.

Zirconium nitride has a particle shape, and the average primary particle diameter is, for example, 20 nm or more and 50 nm or less.

The amount of zirconium nitride to be blended is not particularly limited, but the lower limit is preferably 4.0 parts by mass based on 100 parts by mass of the photosensitive resin to ensure excellent resolution and high hiding power. , 5.0 parts by mass is more preferable, 7.0 parts by weight is even more preferable, and 8.0 parts by weight is particularly preferable from the viewpoint of further improving the hiding power. On the other hand, the upper limit of the amount of zirconium nitride is preferably 20 parts by mass in order to ensure high hiding power and excellent resolution, and more preferably 15 parts by mass in order to further improve resolution. Preferably, 12 parts by mass is particularly preferred.

In the photosensitive resin composition of the present invention, in addition to the above-mentioned components, various additive components such as antifoaming agents, curing accelerators, etc., and zirconium nitride as component (F1) may be added as necessary. Other colorants, flame retardants, non-reactive diluents, etc. may be added as appropriate.

Known antifoaming agents can be used, such as silicone-based, hydrocarbon-based, acrylic-based, and the like. Examples of the curing accelerator include dicyandiamide (DICY) and its derivatives, organic acid hydrazide, diaminomaleonitrile (DAMN) and its derivatives, guanamine and its derivatives, melamine and its derivatives, and amine imide (AI).

Further coloring agents other than the zirconium nitride component (F1) include pigments, dyes, etc., but are not particularly limited, and include white coloring agents, black coloring agents, blue coloring agents, green coloring agents, yellow coloring agents, and purple coloring agents. Depending on the desired color, any of them can be used, such as a coloring agent, an orange coloring agent, a red coloring agent, etc. Containing an additional colorant may contribute to the design of the cured product of the photosensitive resin composition of the present invention. Additional colorants include, for example, inorganic colorants such as titanium dioxide which is a white colorant, phthalocyanine-based colorants such as phthalocyanine green which is a green colorant and phthalocyanine blue and Lionol blue which are blue colorants, and orange colorants. Examples include organic colorants such as diketopyrrolopyrrole, such as certain chromophthalo orange. These additional colorants may be used alone or in combination of two or more.

The flame retardant is a component that imparts flame retardancy to the cured product of the photosensitive resin composition. Examples of the flame retardant include phosphorus-based flame retardants, and among these, organic phosphate-based flame retardants are preferred. Examples of phosphorus flame retardants include tris(chloroethyl)phosphate, tris(2,3-dichloropropyl)phosphate, tris(2-chloropropyl)phosphate, tris(2,3-bromopropyl)phosphate, and tris(bromochloropropyl)phosphate. Halogen-containing phosphate esters such as propyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris(tribromophenyl) phosphate, tris(dibromophenyl) phosphate, and tris(tribromoneopentyl) phosphate Non-halogenated aliphatic phosphate esters such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate; Triphenyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, tricresyl phosphate, trixylenyl Phosphate, xylenyl diphenyl phosphate, tris (isopropylphenyl) phosphate, isopropylphenyl diphenyl phosphate, diisopropylphenyl phenyl phosphate, tris (trimethylphenyl) phosphate, tris (t-butylphenyl) phosphate, hydroxyphenyl diphenyl phosphate, octyldiphenyl phosphate, etc. Non-halogenated aromatic phosphoric acid ester; aluminum tris-diethyl phosphinate, aluminum tris-methylethyl phosphinate, aluminum tris-diphenyl phosphinate, zinc bis-diethyl phosphinate, zinc bismethylethyl phosphinate, zinc bis-diphenyl phosphinate, bis-diethyl phosphine. Metal salts of phosphinic acids such as titanyl tetrakis diethyl phosphinate, titanium tetrakis diethyl phosphinate, titanyl bismethylethyl phosphinate, titanium tetrakis methyl ethyl phosphinate, titanium bis diphenyl phosphinate, titanium tetrakis diphenyl phosphinate, 9,10-dihydro-9- HCA modified types such as oxa-10-phosphaphenanthrene-10-oxide (hereinafter referred to as HCA), addition reaction products of HCA and acrylic acid ester, addition reaction products of HCA and epoxy resin, addition reaction products of HCA and hydroquinone, etc. and phosphine oxide compounds such as diphenylvinylphosphine oxide, triphenylphosphine oxide, trialkylphosphine oxide, and tris(hydroxyalkyl)phosphine oxide.

The non-reactive diluent is a component for adjusting the viscosity, coating properties, dryness to touch, etc. of the photosensitive resin composition. Examples of non-reactive diluents include organic solvents that are inert to each component contained in the photosensitive resin composition. Examples of the organic solvent include ketones such as methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene, and xylene, alcohols such as methanol, ethanol, n-propanol, isopropanol, and cyclohexanol, and cyclohexane and methylcyclohexane. Alicyclic hydrocarbons, petroleum solvents such as petroleum ether and petroleum naphtha, cellosolves, cellosolves such as butyl cellosolve, carbitol, carbitols such as butyl carbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, Examples include esters such as carbitol acetate, butyl carbitol acetate, ethylene glycol acetate, ethylene diglycol acetate, and diethylene glycol monoethyl ether acetate. These organic solvents may be used alone or in combination of two or more.

Next, a method for producing the photosensitive resin composition of the present invention will be explained. The method for producing the photosensitive resin composition of the present invention is not limited to a specific method, and for example, after blending each of the above components in a predetermined ratio, at room temperature (e.g., 25°C), using a three-roll mill, a ball mill, or a sand mill. The composition can be produced by kneading or mixing the ingredients using a kneading means such as a bead mill, a kneader, or a stirring or mixing means such as a super mixer, a planetary mixer, or a trimix. Further, before the above-described kneading or mixing step, a pre-kneading or pre-mixing step may be carried out as necessary.

Next, an example of how to use the photosensitive resin composition of the present invention will be explained. Here, a method for forming an insulating protective film (for example, a solder resist film, etc.) for a printed wiring board using the photosensitive resin composition of the present invention, that is, a printed wiring board having a photocured film of the photosensitive resin composition. We will explain how to obtain this using an example.

The photosensitive resin composition of the present invention prepared as described above is coated on a printed wiring board having a circuit pattern formed by etching copper foil, for example, by a screen printing method, a bar coater method, a blade coater method, or a knife coater method. A coating film is formed by coating to a desired thickness (for example, a thickness of 5.0 μm to 50 μm) using a known coating method such as a roll coater method, a gravure coater method, or a spray coater method. Next, if the photosensitive resin composition contains a non-reactive diluent, in order to volatilize the non-reactive diluent, the photosensitive resin composition is heated at a temperature of about 60° C. to 90° C. for about 10 minutes to 60 minutes. A tack-free coating is formed by pre-drying using heat.

Next, a negative film (photomask) having a pattern in which areas other than the lands of the circuit pattern are made translucent is closely adhered to the coating film, and active energy rays (for example, ultraviolet rays in the wavelength range of 300 to 400 nm) are applied onto the film. The coating film is photocured by irradiation with After photocuring, the coating film is developed by removing the non-exposed areas corresponding to the lands with a dilute alkaline aqueous solution. As the developing method, a spray method, a shower method, etc. are used, and the dilute alkali aqueous solution used is, for example, a 0.5% by mass to 5% by mass sodium carbonate aqueous solution. Next, by performing post-curing (main heat curing treatment) for 20 to 80 minutes in a hot air circulation type dryer at about 130 to 170 degrees Celsius, a photocured material with the desired pattern is formed on the printed wiring board. A certain insulating protective film can be formed. Note that examples of the substrate of the printed wiring board include a rigid substrate and a flexible substrate.

Next, examples of the present invention will be described, but the present invention is not limited to these examples unless it exceeds the spirit thereof.

Examples 1 to 4, Comparative Examples 1 to 3
The components shown in Table 1 below were blended in the proportions shown in Table 1 below, mixed and dispersed at room temperature (approximately 25°C) using three rolls, and then prepared in Examples 1 to 4 and Comparative Examples 1 to 3. A black photosensitive resin composition was prepared. Note that unless otherwise specified, the numbers in Table 1 below indicate parts by mass. In addition, a blank column in Table 1 below means no compounding.

The details of each component in Table 1 are as follows.
(A) Photosensitive resin/Lipoxy SP-4621: Polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxidized epoxy resin with cresol novolac structure, solid content (resin content) 65% by mass, Showa Denko K.K.

(B) Photopolymerization initiator/Omnirad 369: α-aminoalkylphenone photopolymerization initiator, IGM Resins B. V. NCI-831: Oxime ester photopolymerization initiator, ADEKA Co., Ltd.

(C) Reactive diluent/DPHA: Toagosei Co., Ltd.

(D) Epoxy compound・EPICLON N-695: DIC Corporation・YX-4000K: Mitsubishi Chemical Corporation

Filler/barium sulfate B-30: Sakai Chemical Industry Co., Ltd.

(F) Colorant/NITBLACK UB-1: Zirconium nitride (black colorant), transmittance of light with a wavelength of 365 nm (T ₃₆₅ ) 20.1%, transmittance of light with a wavelength of 550 nm (T ₅₅₀ ) 5.4% , T ₃₆₅ / T ₅₅₀ = 3.7, L value 10 to 12, powder, average primary particle size 20 nm to 50 nm, Mitsubishi Materials Electronic Chemicals Co., Ltd./NITBLACK UB-2: Zirconium nitride (black colorant), wavelength 365 nm Light transmittance (T ₃₆₅ ) 28.7%, light transmittance (T ₅₅₀ ) 5.6% at a wavelength of 550 nm, T ₃₆₅ /T ₅₅₀ = 5.1, L value 11-16, powder form, average Primary particle size 20nm to 50nm, Mitsubishi Materials Electronic Chemicals Co., Ltd.

Additives/Melamine: Curing accelerator, Nissan Chemical Co., Ltd./DICY-7: Curing accelerator, Japan Epoxy Resin Co., Ltd./X-50-1095C: Antifoaming agent, Shin-Etsu Chemical Co., Ltd. Non-reactive diluent/ EDGAC: Sanyo Chemicals Co., Ltd.

Colorants other than component (F) MA14: Carbon black (black colorant), Mitsubishi Chemical Corporation, Lionol Blue FG-7351: Phthalocyanine compound (blue colorant), Toyo Ink Mfg. Co., Ltd.

Test board production process Board: Glass epoxy board (FR-4, thickness 1.6 mm), conductor (Cu foil) thickness 22 μm
Substrate surface treatment: Buffing Coating method: Screen printing, DRY film thickness 10 μm
Pre-drying: 75°C, 20 minutes Exposure: 60 mJ/cm ² on the coating film, direct exposure machine manufactured by Oak Co., Ltd. (wavelength 300-500 nm)
Development: 1% by mass sodium carbonate aqueous solution, 30°C, 90 seconds, spray pressure: 0.2MPa
Post cure: 150℃, 60 minutes

Evaluation (1) Resolution The remaining lines of the exposed area formed through a predetermined photomask (line width 10 μm/space 10 μm, line width range 30 μm to 120 μm/space 30 μm to 120 μm range photomask) The missing space was visually confirmed and evaluated based on the following criteria. A rating of △ or higher was considered a pass.
◎: 30μm
○: 40μm
△: 50μm
×: 60 μm or more

◎：ΔＥ＝３．２未満
○：ΔＥ＝３．２以上６．５未満
△：ΔＥ＝６．５以上１０未満
×：ΔＥ＝１０以上 (2) Color Tone Regarding the test substrate prepared as described above, the lightness (L* value), chromatic index (a* value), and chromatic index (b* value) were measured in accordance with JIS-8722. A color difference meter CM-700d (Konica Minolta, Inc.) was used as a measuring instrument. Based on L*=25, a* value=0, and b*=-1, ΔE representing the color difference was calculated from the following formula, and the color tone was evaluated based on the following criteria, and a rating of ○ or higher was considered to be a pass.

◎: ΔE = less than 3.2 ○: ΔE = 3.2 or more and less than 6.5 △: ΔE = 6.5 or more and less than 10 ×: ΔE = 10 or more

The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1 below.

From Table 1 above, Examples 1 to 4, in which zirconium nitride, which is a black colorant, instead of carbon black, was blended as a colorant had excellent resolution with a line width of 50 μm or less, and color tone. was less than ΔE=6.5, and a photocured product with excellent blackness and high hiding power could be obtained. In particular, zirconium nitride was blended with a transmittance (T ₃₆₅ ) of 28.7% for light at a wavelength of 365 nm, a transmittance (T ₅₅₀ ) for light at a wavelength of 550 nm of 5.6%, and T ₃₆₅ /T ₅₅₀ = 5.1. In Examples 1 and 2, the transmittance (T ₃₆₅ ) of light with a wavelength of 365 nm is 20.1%, the transmittance (T ₅₅₀ ) of light with a wavelength of 550 nm is 5.4%, and T ₃₆₅ /T ₅₅₀ = 3.7. The resolution was further improved compared to Examples 3 and 4. In addition, Examples 1 and 3 in which approximately 8.7 parts by mass of zirconium nitride was blended with respect to 100 parts by mass of photosensitive resin were compared with Examples 1 and 3 in which approximately 6.4 parts by mass of zirconium nitride was blended with respect to 100 parts by mass of photosensitive resin. Compared to Examples 2 and 4, a photocured product with a further reduced ΔE value and further improved hiding power could be obtained.

In Examples 1 to 4, the photosensitive resin is a polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin having a cresol novolac skeleton, and the epoxy compound is a cresol novolac type epoxy resin that is the same type of epoxy resin. Contains resin.

On the other hand, in Comparative Examples 1 to 3 in which carbon black was blended as a black colorant, resolution could not be obtained. Further, in Comparative Example 3, in which approximately 6.4 parts by mass of carbon black was blended with 100 parts by mass of the photosensitive resin, high hiding power could not be obtained.

The photosensitive resin composition of the present invention can provide a photocured product having excellent resolution and hiding power, so it can be used, for example, as an insulating coating (for example, a solder resist film) applied to a printed wiring board. Highly useful in the field.

Claims (13)

Contains (A) a photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, (E) a filler, and (F) a colorant,
A photosensitive resin composition in which the colorant (F) contains (F1) zirconium nitride. The photosensitive resin composition according to claim 1, wherein the (F1) 50 ppm dispersion of zirconium nitride has a transmittance of light at a wavelength of 365 nm of 18.0% or more. The photosensitive resin composition according to claim 1, wherein the (F1) 50 ppm dispersion of zirconium nitride has a transmittance of light at a wavelength of 365 nm of 25.0% or more. 4. The 50 ppm dispersion of zirconium nitride (F1) has a ratio of transmittance of light with a wavelength of 365 nm to transmittance of light with a wavelength of 550 nm of 3.0 or more. Photosensitive resin composition. 4. The 50 ppm dispersion of zirconium nitride (F1) has a ratio of transmittance of light with a wavelength of 365 nm to transmittance of light with a wavelength of 550 nm of 4.5 or more. Photosensitive resin composition. 4. The photosensitive resin according to claim 1, wherein the (F1) zirconium nitride is contained in an amount of 4.0 parts by mass or more and 20 parts by mass or less based on 100 parts by mass (solid content) of the photosensitive resin (A). Photosensitive resin composition. 4. The photosensitive resin according to claim 1, wherein the (F1) zirconium nitride is contained in 7.0 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass (solid content) of the photosensitive resin (A). Photosensitive resin composition. The photosensitive resin composition according to any one of claims 1 to 3, wherein the (F1) zirconium nitride has an L value of 8 or more and 18 or less. The photosensitive resin composition according to any one of claims 1 to 3, which does not contain carbon black. 4. The photopolymerization initiator (B) includes at least one selected from the group consisting of an α-aminoalkylphenone photopolymerization initiator and an oxime ester photopolymerization initiator. The photosensitive resin composition described in . The photosensitive resin (A) is prepared by reacting a radically polymerizable unsaturated monocarboxylic acid with at least a portion of the epoxy groups of a polyfunctional epoxy resin having two or more epoxy groups in one molecule to form a radically polymerizable unsaturated monocarboxylic acid. A polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin having a structure obtained by obtaining a carboxylated epoxy resin and reacting the generated hydroxyl group with a polybasic acid and/or a polybasic acid anhydride; (D) Any one of claims 1 to 3, wherein the epoxy compound contains an epoxy resin of the same type as the polyfunctional epoxy resin forming the skeleton of the polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resin. The photosensitive resin composition according to item 1. A photocured product of the photosensitive resin composition according to any one of claims 1 to 3. A printed wiring board comprising a photocured film of the photosensitive resin composition according to any one of claims 1 to 3.