JP2022050081A - Photosensitive resin composition - Google Patents

Abstract

To provide a photosensitive resin composition capable of forming a cured product excellent in gold plating resistance without impairing various characteristics such as storage stability, alkali developability, and heat resistance.SOLUTION: The photosensitive resin composition contains (A) a carboxyl group-containing photosensitive resin, (B) a compound of cyanuric acid and a metal, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound.SELECTED DRAWING: None

Description

The present invention uses a photosensitive resin composition that can be used as a coating material, for example, an insulating coating material for coating a conductor circuit pattern formed on a substrate such as a printed wiring board, and the photosensitive resin composition. It relates to a cured photocured material and a substrate such as a printed wiring board coated with the photocured material.

A circuit pattern of a conductor (for example, copper foil) is formed on a board such as a printed wiring board, and electronic components are mounted on the soldered lands of the conductor circuit pattern by soldering, and the circuit parts other than the soldered lands are protected. It is covered with an insulating film (solder resist film) as a film. As the insulating film, a cured film of a photosensitive resin composition containing a carboxyl group-containing photosensitive resin, an epoxy compound, and a photopolymerization initiator may be used. Further, in recent years, due to the high performance of electronic devices, the electronic components connected to the printed wiring board have been diversified. Therefore, the printed wiring board may be required to have versatility in which various electronic components can be mounted.

In order to impart versatility to the printed wiring board, the surface of the insulating coating formed on the printed wiring board may be subjected to surface treatment such as gold plating. However, when the surface of the insulating coating is subjected to the gold plating treatment, the adhesion of the insulating coating to the conductor circuit is lowered, and the gold plating resistance may not be obtained in some cases.

Therefore, in order to impart gold plating resistance to the insulating film of the printed wiring board, a photosensitive resin composition using a titanosen-based photopolymerization initiator as a photopolymerization initiator has been proposed (Patent Document 1).

On the other hand, in recent years, due to the miniaturization of electronic devices and the like, there is a demand for thinner substrates such as printed wiring boards, and flexible printed wiring boards may be used. In the flexible printed wiring board, the cured film of the photosensitive resin composition is required to be thinned to, for example, about 20 μm in thickness. Further, in the process of mounting electronic components on a flexible printed wiring board, a process of heat treatment at a high temperature and in a short time is often used from the viewpoint of improving productivity.

However, in the cured film of the conventional photosensitive resin composition, when heat treatment is performed at a high temperature for a short time in a thin film state, the adhesion between the cured film and the conductor circuit is lowered, and as a result, the gold resistance is reduced. The plating property may be deteriorated. In order to improve the gold plating resistance, mercaptobenzoxazole or the like is added to the photosensitive resin composition as an adhesion-imparting agent, but it is also heat-treated at a high temperature and for a short time in a thin film state. However, there is a problem that the adhesion between the cured film and the conductor circuit is lowered, and sufficient gold plating resistance may not be obtained.

International Publication No. 2006/076554

In view of the above circumstances, the present invention provides a photosensitive resin composition capable of forming a cured product having excellent gold plating resistance without impairing various properties such as storage stability, alkali developability, and heat resistance. The purpose.

The gist of the structure of the present invention is as follows.
[1] A carboxyl group-containing photosensitive resin, (B) a compound of cyanuric acid and a metal, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound. A photosensitive resin composition containing.
[2] The photosensitive property according to [1], wherein the compound (B) cyanuric acid and the metal is contained in an amount of 0.10 parts by mass or more and 14 parts by mass or less with respect to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin. Resin composition.
[3] The photosensitive resin composition according to [1] or [2], wherein the compound of (B) cyanuric acid and a metal is columnar particles.
[4] The invention according to any one of [1] to [3], wherein the average particle size of the compound (B) cyanuric acid and the metal measured by a laser method is 0.5 μm or more and 5.0 μm or less. Photosensitive resin composition.
[5] The photosensitive resin composition according to any one of [1] to [4], wherein the compound of (B) cyanuric acid and a metal is zinc cyanurate.
[6] The (A) carboxyl group-containing photosensitive resin is a radically polymerizable unsaturated mono in (A-1) at least a part of the epoxy groups of the polyfunctional epoxy resin having two or more epoxy groups in one molecule. A polybasic acid-modified unsaturated monocarboxylic acid having a structure obtained by reacting a carboxylic acid to obtain an unsaturated monocarboxylic oxide epoxy resin and reacting the generated hydroxyl group with a polybasic acid and / or a polybasic acid anhydride. An epoxy resin, a polyfunctional epoxy resin having two or more epoxy groups in one molecule (A-2), and at least one linear or branched aliphatic having 10 or more carbon atoms per carboxyl group. An acid-modified long chain having a structure obtained by adding a polybasic acid and / or a polybasic acid anhydride to an unsaturated carboxylic oxide epoxy resin which is a reaction product of a carboxylic acid and a radically polymerizable unsaturated monocarboxylic acid. The photosensitive resin composition according to any one of [1] to [5], which is at least one selected from the group consisting of a hydrocarbon structure-containing epoxy resin.
[7] The photosensitive resin composition according to any one of [1] to [6], wherein the (D) reactive diluent contains caprolactone-modified (meth) acrylate.
[8] The photocured product of the photosensitive resin composition according to any one of [1] to [7].
[9] A printed wiring board having a photocurable film of the photosensitive resin composition according to any one of [1] to [7].

According to the aspect of the photosensitive resin composition of the present invention, (A) a carboxyl group-containing photosensitive resin, (B) a compound of cyanuric acid and a metal, (C) a photopolymerization initiator, and (D) reactivity. By containing the diluent and the (E) epoxy compound, a photosensitive resin capable of forming a cured product having excellent gold plating resistance without impairing various properties such as storage stability, alkali developability, and heat resistance. The composition can be obtained.

According to the aspect of the photosensitive resin composition of the present invention, 0.1 part by mass or more and 14 parts by mass or less of (B) a compound of cyanuric acid and a metal with respect to 100 parts by mass of (A) a photosensitive resin containing a carboxyl group. By including it, it is possible to further improve storage stability and alkali developability while obtaining excellent gold plating resistance.

According to the aspect of the photosensitive resin composition of the present invention, the gold plating resistance can be more reliably improved because the compound (B) cyanuric acid and the metal is columnar particles.

According to the aspect of the photosensitive resin composition of the present invention, the average particle size measured by the laser method of (B) a compound of cyanuric acid and a metal is 0.5 μm or more and 5.0 μm or less, so that gold-resistant plating is performed. The sex can be improved more reliably.

According to the aspect of the photosensitive resin composition of the present invention, the (A) carboxyl group-containing photosensitive resin is (A-1) an epoxy group of a polyfunctional epoxy resin having two or more epoxy groups in one molecule. A structure obtained by reacting at least a part of a radically polymerizable unsaturated monocarboxylic acid to obtain an unsaturated monocarboxylic oxide epoxy resin and reacting the generated hydroxyl group with a polybasic acid and / or a polybasic acid anhydride to obtain a structure. A polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin and / or a polyfunctional epoxy resin having two or more epoxy groups in one molecule and having 10 or more carbon atoms per carboxyl group. A polybasic acid and / or a polybasic acid anhydride is added to an unsaturated carboxylic oxide epoxy resin which is a reaction product of at least one linear or branched aliphatic carboxylic acid and a radically polymerizable unsaturated monocarboxylic acid. By the acid-modified long-chain hydrocarbon structure-containing epoxy resin having a structure obtained by addition, heat resistance and gold plating resistance can be reliably improved.

According to the aspect of the photosensitive resin composition of the present invention, by containing (D) the reactive diluent containing caprolactone-modified (meth) acrylate, it is possible to obtain a cured product having excellent flexibility and further improved heat resistance. can.

Next, the photosensitive resin composition of the present invention will be described in detail. The photosensitive resin composition of the present invention comprises (A) a carboxyl group-containing photosensitive resin, (B) a compound of cyanuric acid and a metal, (C) a photopolymerization initiator, and (D) a reactive diluent. (E) Contains an epoxy compound. The photosensitive resin composition of the present invention can form a cured product having excellent gold plating resistance without impairing various properties such as storage stability, alkali developability, and heat resistance.

(A) Carboxyl group-containing photosensitive resin The chemical structure of the carboxyl group-containing photocurable resin is not particularly limited, and examples thereof include a carboxyl group-containing resin having one or more photosensitive unsaturated double bonds. As an example of the carboxyl group-containing photosensitive resin, (A-1) a radically polymerizable unsaturated monocarboxylic acid is reacted with at least a part of the epoxy group of the polyfunctional epoxy resin having two or more epoxy groups in one molecule. A polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin having a structure obtained by reacting a generated hydroxyl group with a polybasic acid or a polybasic acid anhydride (hereinafter, “A”). -1 resin "), (A-2) A polyfunctional epoxy resin having two or more epoxy groups in one molecule and at least one type having 10 or more carbon atoms per carboxyl group. Obtained by adding a polybasic acid and / or a polybasic acid anhydride to an unsaturated carboxylic oxide epoxy resin which is a reaction product of a linear or branched aliphatic carboxylic acid and a radically polymerizable unsaturated monocarboxylic acid. Examples thereof include an acid-modified long-chain hydrocarbon structure-containing epoxy resin having such a structure (hereinafter, may be referred to as “A-2 resin”). By using the above-mentioned A-1 resin and A-2 resin, the cured product of the photosensitive resin composition can surely improve the heat resistance and the gold plating resistance.

<A-1 resin>
The chemical structure of the polyfunctional epoxy resin is not particularly limited, and for example, a biphenyl aralkyl type epoxy resin, a phenyl aralkyl type epoxy resin, a biphenyl type epoxy resin, a naphthalene type epoxy resin, a dicyclopentadiene type epoxy resin, a silicone-modified epoxy resin, etc. Rubber-modified epoxy resin, ε-caprolactone-modified epoxy resin, bisphenol A type epoxy resin, phenol novolac type epoxy resin such as bisphenol F type epoxy resin, cresol novolak type epoxy resin such as ortho-cresol novolak type, bisphenol A novolak type epoxy Resin, cyclic aliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol modified novolak type epoxy resin, polyfunctional modified novolak type epoxy resin, etc. Can be mentioned. These polyfunctional epoxy resins may be used alone or in combination of two or more.

The epoxy equivalent of the polyfunctional epoxy resin is not particularly limited, and for example, the upper limit thereof is preferably 3000 g / eq, more preferably 2000 g / eq, still more preferably 1000 g / eq, and particularly preferably 500 g / eq. On the other hand, the lower limit is preferably 100 g / eq, and particularly preferably 200 g / eq.

Radical-polymerizable unsaturated monocarboxylic acid Examples of the radical-polymerizable unsaturated monocarboxylic acid include acrylic acid and / or methacrylic acid (hereinafter, may be referred to as "(meth) acrylic acid"), crotonic acid, and tiglic acid. , Angelic acid, tiglic acid and the like. These radically polymerizable unsaturated monocarboxylic acids may be used alone or in combination of two or more.

Polybasic acid and / or polybasic acid anhydride The polybasic acid and / or polybasic acid anhydride is not particularly limited, and either saturated or unsaturated can be used. Examples of the polybasic acid include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-. Tetrahydrophthalic acids such as ethyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid Examples thereof include acids, hexahydrophthalic acids such as 4-ethylhexahydrophthalic acid, trimellitic acid, pyromellitic acid and diglycolic acid. Examples of the polybasic acid anhydride include the above-mentioned polybasic acid anhydride. These compounds may be used alone or in combination of two or more.

<A-2 resin>
Polyfunctional epoxy resin The polyfunctional epoxy resin is not particularly limited, and for example, like the A-1 resin, a biphenyl aralkyl type epoxy resin, a phenyl aralkyl type epoxy resin, a biphenyl type epoxy resin, a naphthalene type epoxy resin, and a dicyclopentadiene. Rubber-modified epoxy resin such as type epoxy resin, silicone-modified epoxy resin, ε-caprolactone-modified epoxy resin, bisphenol A type epoxy resin, phenol novolac type epoxy resin such as bisphenol F type epoxy resin, cresol novolak such as ortho-cresol novolak type Type epoxy resin, bisphenol A novolak type epoxy resin, cyclic aliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol modified novolak type epoxy resin, Examples thereof include a polyfunctional modified novolak type epoxy resin. These polyfunctional epoxy resins may be used alone or in combination of two or more. Of these, the biphenyl aralkyl type epoxy resin is preferable from the viewpoint of heat resistance, gold plating resistance, flexibility and insulation reliability of the cured product of the photosensitive resin composition.

Linear or branched aliphatic carboxylic acid having 10 or more carbon atoms per carboxyl group A linear or branched aliphatic carboxylic acid having 10 or more carbon atoms per carboxyl group is polyfunctional. By introducing the long-chain hydrocarbon structure derived from the above aliphatic carboxylic acid into the polyfunctional epoxy resin in response to the epoxy group of the epoxy resin, the heat resistance of the cured product of the photosensitive resin composition containing the photosensitive resin , Gold plating resistance, flexibility, and insulation reliability can be improved. The linear or branched aliphatic carboxylic acid having 10 or more carbon atoms per carboxyl group is not particularly limited, and either saturated or unsaturated can be used. Examples of the aliphatic carboxylic acid include a monobasic acid having 10 or more carbon atoms and a dibasic acid having 20 or more carbon atoms. From the viewpoint of flexibility and dryness to the touch, the monobasic acid and the dibase The acid is preferably linear or branched with two or less side chains having 2 or less carbon atoms.

Further, the aliphatic carboxylic acid of the dibasic acid has a long chain hydrocarbon structure derived from the aliphatic carboxylic acid of the dibasic acid introduced into the polyfunctional epoxy resin, and has a different epoxy group of the polyfunctional epoxy resin. The dibasic acid having a chain hydrocarbon structure is bonded to each other via the above-mentioned aliphatic carboxylic acid. Therefore, the aliphatic carboxylic acid of the dibasic acid is obtained by covalently bridging the relatively rigid skeleton of the polyfunctional epoxy resin with a highly flexible long-chain hydrocarbon skeleton derived from the aliphatic carboxylic acid. It can be configured. As a result, the above-mentioned aliphatic carboxylic acid of dibasic acid is preferable in that it imparts a structure excellent in flexibility, heat resistance and gold plating resistance of the cured product to the epoxy resin. Further, the flexibility of the cured product can be improved by introducing a large amount of highly flexible long-chain hydrocarbon skeleton derived from the above-mentioned aliphatic carboxylic acid, and the number of carbon atoms per above-mentioned carboxyl group is 10. By using a monobasic acid having 10 or more carbon atoms per carboxyl group in combination with the above dibasic acid, the above aliphatic carboxylic acid, the polyfunctional epoxy resin, and the ethylenically unsaturated group-containing carboxylic acid are used in combination. The molecular weight of the reaction product with the acid can be appropriately controlled while improving the composition ratio of the component derived from the aliphatic carboxylic acid. In this way, by appropriately adjusting the molecular weight, it is possible to improve the solubility in an alkaline developer (that is, alkaline developability), the flexibility of the cured product, the heat resistance, and the gold plating resistance in a well-balanced manner. Become.

The carboxylic acid having 10 or more carbon atoms per carboxyl group is not particularly limited, and examples of the monobasic acid include capric acid (decanoic acid: C10), undecic acid (C11), and lauric acid (dodecanoic acid). : C12), tridecic acid (C13), myristic acid (C14), pentadecic acid (C15), palmitic acid (hexadecanoic acid: C16), margaric acid (heptadecanoic acid: C17), stearic acid (C18), tubercrostearic acid (C19), arachidic acid (C20), behenic acid (C22), tricosyl acid (C23), tetracosanoic acid (C24), hexacosanoic acid (C26), octacosanoic acid (C28), triacanthanoic acid (C30) and the like. ..

Examples of the dibasic acid include eicosane diic acid (C20), ethyl octadecane diic acid (C20), eicosadien diic acid (C20), vinyl octadecaen diic acid (C20), and dimethyleicosadien diic acid (C22). Examples thereof include C36 dimer acid produced by a dimerization reaction of unsaturated fatty acids such as dimethyleicosan diic acid (C22), diphenylhexadecane diic acid (C28) and oleic acid (C18). The above-mentioned carboxylic acid having 10 or more carbon atoms per carboxyl group may be used alone or in combination of two or more. Further, if necessary, a carboxylic acid having 10 or more carbon atoms per carboxyl group and a monobasic acid and / or a dibasic acid having 9 or less carbon atoms per carboxyl group are used in combination. You may.

The ratio (preparation ratio) of the linear or branched aliphatic carboxylic acid having 10 or more carbon atoms per carboxyl group in the photosensitive resin is not particularly limited, but the lower limit thereof is flexibility. 10% by mass is preferable, and 15% by mass is particularly preferable, from the viewpoint of further improving the insulation reliability and adjusting the introduction amount of the polybasic acid and / or the polybasic acid anhydride to adjust the solid content acid value. On the other hand, the upper limit is that the amount of radically polymerizable unsaturated monocarboxylic acid introduced (that is, photosensitive) is maintained, and the amount of polybasic acid and / or polybasic acid anhydride introduced is adjusted to be solid. From the viewpoint of adjusting the acid anhydride value, 30% by mass is preferable, and 25% by mass is particularly preferable.

Radical-polymerizable unsaturated monocarboxylic acid Examples of the radical-polymerizable unsaturated monocarboxylic acid include (meth) acrylic acid, crotonic acid, tiglic acid, angelic acid, and cinnamic acid, as in the case of A-1 resin. can. These radically polymerizable unsaturated monocarboxylic acids may be used alone or in combination of two or more. The ratio (charge ratio) of the radically polymerizable unsaturated monocarboxylic acid is not particularly limited, but the lower limit thereof further improves the sensitivity, and the amount of polybasic acid and / or polybasic acid anhydride introduced and the solid. From the viewpoint of adjusting the acid anhydride value, 2.0% by mass is preferable, and 3.0% by mass is particularly preferable. On the other hand, the upper limit is to maintain the introduction amount of the carboxylic acid having 10 or more carbon atoms per carboxyl group, and to adjust the introduction amount of the polybasic acid and / or the polybasic acid anhydride. From the viewpoint of adjusting the solid content acid value, 10% by mass is preferable, and 5.0% by mass is particularly preferable.

Polybasic acid and / or polybasic acid anhydride A free carboxyl group is introduced by the addition reaction of the polybasic acid and / or the polybasic acid anhydride with the hydroxyl group generated in the unsaturated carboxylic oxide epoxy resin. The polybasic acid and / or the polybasic acid anhydride is not particularly limited, and either saturated or unsaturated can be used. Polybasic acids include, for example, succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4- Tetrahydrophthalic acids such as ethyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid Examples thereof include acids, hexahydrophthalic acids such as 4-ethylhexahydrophthalic acid, trimellitic acid, pyromellitic acid and diglycolic acid. Examples of the polybasic acid anhydride include the above-mentioned polybasic acid anhydride. These compounds may be used alone or in combination of two or more. The ratio of polybasic acid and / or polybasic acid anhydride (preparation ratio) is not particularly limited, but the lower limit thereof is 7.0% by mass from the viewpoint of good alkali developability and adjustment of solid acid value. It is preferable, and 9.0% by mass is particularly preferable. On the other hand, the upper limit is preferably 16% by mass, particularly preferably 14% by mass, from the viewpoint of surely preventing a decrease in insulation reliability and adjusting the solid acid value.

(A) As the carboxyl group-containing photosensitive resin, A-1 resin or A-2 resin may be used, or A-1 resin and A-2 resin may be used in combination.

The mass average molecular weight of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit thereof is preferably 3000, more preferably 5000, from the viewpoint of toughness and dryness to the touch of the cured product of the photosensitive resin composition. 7000 is particularly preferable. On the other hand, the upper limit of the mass average molecular weight of the carboxyl group-containing photosensitive resin is preferably 200,000, more preferably 100,000, and more preferably 50,000, from the viewpoint of preventing an increase in the viscosity of the photosensitive resin composition and obtaining excellent coatability. Is particularly preferable. The "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.

The acid value of the carboxyl group-containing photosensitive resin is not particularly limited, and for example, the lower limit thereof is preferably 30 mgKOH / g and particularly preferably 40 mgKOH / g from the viewpoint of reliably obtaining alkali developability. 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 preventing dissolution of the exposed portion by the alkaline developer, for example, ensuring the moisture resistance and insulation reliability of the photocured product. From the point of view of gain, 150 mgKOH / g is particularly preferable.

(B) Compound of cyanuric acid and metal (B) By blending the compound of cyanuric acid and metal as a component, the cured film of the photosensitive resin composition of the present invention has a high temperature in a thinned state. -Excellent gold plating resistance even after short-time heat treatment. It is considered that the compounding of cyanuric acid and the metal compound improves the adhesion between the cured film of the photosensitive resin composition and the conductor circuit, and as a result, the gold plating resistance is improved.

The appearance of the cyanuric acid and metal compound is powdery. The shape of the compound of cyanuric acid and the metal is not particularly limited, but for example, columnar particles are preferable from the viewpoint of more reliably improving the gold plating resistance. The average particle size of the compound of cyanuric acid and the metal is not particularly limited, but the average particle size measured by the laser method is preferably 0.5 μm or more and 5.0 μm or less from the viewpoint of more reliably improving the gold plating resistance. , 1.0 μm or more and 3.0 μm or less are more preferable, and 1.3 μm or more and 2.3 μm or less are particularly preferable. The "average particle size measured by the laser method" means the average particle size measured by the particle size distribution measuring device using the laser diffraction / scattering method. Specific examples of the compound of cyanuric acid and the metal include zinc cyanuric acid.

The content of the cyanuric acid and the metal compound (for example, zinc cyanuric acid) is not particularly limited, but the lower limit thereof is 100 parts by mass of the carboxyl group-containing photosensitive resin from the viewpoint of surely improving the gold plating resistance. On the other hand, 0.10 parts by mass is preferable, 0.30 parts by mass is more preferable, and 0.50 parts by mass is particularly preferable. On the other hand, the upper limit of the content of cyanuric acid and a metal compound (for example, zinc cyanurate) further improves the storage stability of the photosensitive resin composition and the alkali developability of the photocurable product of the photosensitive resin composition. 30 parts by mass is preferable, 20 parts by mass is more preferable, and 14 parts by mass is particularly preferable.

(C) Photopolymerization initiator The photopolymerization initiator as a component of (C) is not particularly limited as long as it is generally used, and is, for example, 1,2-octanedione, 1- [4- (phenylthio). ) -2- (O-benzoyloxime)], Etanone 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -1- (0-acetyloxime), 2- ( Acetyloxyimiminomethyl) Thioxanthen-9-one, 1,8-octanedione, 1,8-bis [9-ethyl-6-nitro-9H-carbazole-3-yl]-, 1,8-bis (O) -Acetyloxime), 1,8-octanedione, 1,8-bis [9- (2-ethylhexyl) -6-nitro-9H-carbazole-3-yl]-, 1,8-bis (O-acetyloxime) ), (Z)-(9-ethyl-6-nitro-9H-carbazole-3-yl) (4-((1-methoxypropane-2-yl) oxy) -2-methylphenyl) methanone O-acetyloxime Oxime ester-based photopolymerization initiators such as 2-benzyl-2- (dimethylamino) -1- (4-morpholinophenyl) -1-butanone, 2-methyl-1- (4-methylthiophenyl) -2- Examples thereof include α-aminoalkylphenone-based photopolymerization initiators such as morpholinopropane-1-one. Examples of the photopolymerization initiator other than the oxime ester-based photopolymerization initiator and the α-aminoalkylphenone-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoin, benzoin methyl ether, and benzoin. Ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 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, dichlorbenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorthioxanthone, 2,4- Examples thereof include dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenonedimethylketal, P-dimethylaminobenzoic acid ethyl ester and the like. These photopolymerization initiators may be used alone or in combination of two or more.

The content of the photopolymerization initiator is not particularly limited, but is preferably 1.0 part by mass or more and 10 parts by mass or less, and 1.5 parts by mass or more and 5.0 parts by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin. Part or less is particularly preferable.

(D) Reactive Diluent The reactive diluent as a component of (D) is, for example, a photopolymerizable monomer and has at least one polymerizable double bond per molecule, preferably at least two polymerizable double bonds per molecule. It is a compound. The reactive diluent reinforces the photocuring of the photosensitive resin composition and contributes to the formation of a photocured product having acid resistance, alkali resistance and the like.

Examples of the reactive diluent include monofunctional (meth) acrylate monomers, bifunctional (meth) acrylate monomers, and trifunctional or higher (meth) acrylate monomers. Specific examples of the (meth) acrylate monomer include monofunctional (meth) acrylate monomers such as 2-hydroxyethyl methacrylate, phenoxyethyl methacrylate, and diethylene glucol monomethacrylate, 2-hydroxy-3-phenoxypropyl acrylic rate; , 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, hydroxy 2 such as neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, ethylene oxide-modified di (meth) phosphate acrylate, cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, etc. Functional (meth) acrylate monomer; trimethylol propanetri (meth) acrylate, ditrimethylol propanetetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) Trifunctional or higher (meth) acrylate, propylene oxide-modified trimethylolpropanetri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. Meta) Acrylate monomer can be mentioned. Further, specific examples of the (meth) acrylate monomer include caprolactone-modified (meth) acrylate. These may be used alone or in combination of two or more.

As the (meth) acrylate monomer, caprolactone-modified (meth) acrylate is preferable because a cured product having excellent flexibility and further improved heat resistance can be obtained. The caprolactone-modified (meth) acrylate is not particularly limited as long as it is a caprolactone-modified form of the (meth) acrylate compound, and examples thereof include caprolactone-modified polyfunctional (meth) acrylate. Examples of the caprolactone-modified polyfunctional (meth) acrylate include a 5-functional or higher (meth) acrylate such as a caprolactone-modified dipentaerythritol hexa (meth) acrylate and a caprolactone-modified dipentaerythritol penta (meth) acrylate, and a caprolactone-modified pentaerythritol tetra. Tetrafunctional (meth) acrylates such as (meth) acrylates, caprolactone-modified ditrimethylolpropane tetra (meth) acrylates, caprolactone-modified dipentaerythritol tetra (meth) acrylates, caprolactone-modified pentaerythritol tri (meth) acrylates, caprolactone-modified trimethylol Examples thereof include 2-3 functional (meth) acrylates such as propanetri (meth) acrylate, caprolactone-modified dipentaerythritol tri (meth) acrylate, and caprolactone-modified dicyclopentenyldi (meth) acrylate. These may be used alone or in combination of two or more.

The average number of repeating units of caprolactone in the caprolactone-modified (meth) acrylate is not particularly limited, but is preferably 1 or more and 5 or less, and particularly preferably 1 or more and 3 or less.

The content 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, and particularly 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin. preferable.

(E) Epoxy compound The epoxy compound as a component of (E) is for increasing the crosslink density of the cured coating film to obtain a sufficiently cured coating film. Examples of the epoxy compound include epoxy resins. Examples of the epoxy resin include rubber-modified epoxy resins such as biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, and silicone-modified epoxy resin, and ε-caprolactone. Phenol novolak type epoxy resin such as modified epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolak type epoxy resin such as ortho-cresol novolak type, bisphenol A novolak type epoxy resin, cyclic aliphatic polyfunctional epoxy resin , Glycidyl ester type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol-modified novolak type epoxy resin, polyfunctional modified novolac type epoxy resin and the like can be mentioned. These epoxy compounds may be used alone or in combination of two or more.

The content of the epoxy compound is not particularly limited, but is preferably 10 parts by mass or more and 80 parts by mass or less, and particularly preferably 20 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin.

In the photosensitive resin composition of the present invention, in addition to the above-mentioned components (A) to (E), various components such as a colorant, a matting agent, a flame retardant, and an additive can be used as needed. A defoaming agent, a filler, a non-reactive diluent and the like can be appropriately contained.

The colorant is not particularly limited, such as a pigment and a pigment. Further, as the color of the colorant, any color such as a white colorant, a blue colorant, a green colorant, a yellow colorant, a purple colorant, a black colorant, and a red colorant can be used. Examples of the colorant include inorganic colorants such as titanium oxide (rutyl-type titanium oxide and anatase-type titanium oxide) which is a white colorant, carbon black which is a black colorant, and acetylene black. Further, organic colorants such as phthalocyanine green which is a green colorant and phthalocyanine type such as phthalocyanine blue and lionol blue which are blue colorants can be mentioned.

The matting agent is for imparting a matte appearance to the cured product of the photosensitive resin composition. Examples of the matting agent include inorganic matting agents such as powdered silica, powdered barium sulfate, and powdered alumina, and organic matting agents such as particulate urethane resin.

The flame retardant is for imparting flame retardancy to the cured product of the photosensitive resin composition. Examples of the flame retardant include phosphorus-based flame retardants. Examples of the phosphorus-based flame retardant include tris (chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-bromopropyl) phosphate, and tris (bromo). Halogen-containing phosphoric acid such as chloropropyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris (tribromophenyl) phosphate, tris (dibromophenyl) phosphate, tris (tribromoneopentyl) phosphate. Esters; Non-halogen 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, trixylate. Nylphosphate, xylenyldiphenyl phosphate, tris (isopropylphenyl) phosphate, isopropylphenyldiphenyl phosphate, diisopropylphenylphenyl phosphate, tris (trimethylphenyl) phosphate, tris (t-butylphenyl) phosphate, hydroxyphenyldiphenyl phosphate, octyldiphenyl phosphate. Non-halogen aromatic phosphate esters such as: Aluminum Trisdiethylphosphine, Aluminum Trismethylethylphosphine, Aluminum Trisdiphenylphosphine, Zinc bisdiphenylphosphine, Zinc bismethylethylphosphine, Zinc bisdiphenylphosphine, Bisdiethyl Metallic salts of phosphinic acid such as titanyl phosphine, titanium tetrakisdiethylphosphine, titanyl bismethylethylphosphine, titanium tetrakismethylethylphosphine, titanyl bisdiphenylphosphine, titanium tetrakisdiphenylphosphine, 9,10-dihydro-9. Examples thereof include phosphine oxide compounds such as -oxa-10-phosphaphenanthrene-10-oxide, diphenylvinylphosphine oxide, triphenylphosphine oxide, trialkylphosphine oxide, and tris (hydroxyalkyl) phosphine oxide. Of these, organic phosphate-based flame retardants are preferred.

Additives include dicyandiamide (DICY) and its derivatives, melamine and its derivatives, boron trifluoride-amine complex, organic acid hydrazide, diaminomaleonitrile (DAMN) and its derivatives, guanamine and its derivatives, amineimide (AI) and the like. Can be mentioned as a curing accelerator.

Examples of the defoaming agent include silicone-based, hydrocarbon-based and acrylic polymer-based. Examples of the filler include talc, aluminum hydroxide, mica and the like.

The non-reactive diluent is for adjusting the viscosity, drying property, coatability, etc. of the photosensitive resin composition. Examples of the non-reactive diluent include organic solvents. Examples of the organic solvent include ketones such as methyl ethyl ketone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, n-propanol, isopropanol and cyclohexanol, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. , Cellosolves, cellosolves such as butyl cellosolve, carbitols such as carbitol and butyl carbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, diethylene glycol monomethyl ether acetate, ethyl di Examples thereof include esters such as glycol acetate. These may be used alone or in combination of two or more.

The method for producing the photosensitive resin composition of the present invention described above is not limited to a specific method. It can be kneaded or mixed by a mixing and kneading means such as a roll, a ball mill, a sand mill, a bead mill and a kneader, or a stirring and mixing means such as a super mixer, a planetary mixer and a trimix. Further, if necessary, pre-kneading or pre-mixing may be performed before kneading or mixing.

Next, an example of how to use the photosensitive resin composition of the present invention will be described. Here, an example is a method in which the photosensitive resin composition of the present invention is applied onto a printed wiring board (here, a flexible printed wiring board) to form an insulating film such as a solder resist film on the flexible printed wiring board. I will explain.

The photosensitive resin composition of the present invention produced as described above is applied to the flexible printed wiring board with a desired thickness (for example, a thickness of 5 to 30 μm). As the coating means, any known means can be used, and examples thereof include screen printing, bar coater, spray coating, applicator, blade coater, knife coater, roll coater, gravure coater and the like. After coating the photosensitive resin composition, if necessary, the photosensitive resin composition is pre-dried in a heating device (for example, a hot air furnace, a far-infrared furnace, etc.), and the photosensitive resin composition is subjected to a non-reactive diluent. Is volatilized to make the surface of the coating film tack-free. Examples of the pre-drying conditions include a drying temperature of 60 ° C. to 90 ° C. and a drying time of 10 minutes to 60 minutes. After pre-drying, a negative film having a translucent pattern other than the land of the circuit pattern is brought into close contact with the coated photosensitive resin composition, and ultraviolet rays (for example, wavelength 300 to 400 nm) are irradiated from above the negative film. The coating film of the photosensitive resin composition is photocured to form a photocured product. Next, the photocured product, which is a coating film, is developed by removing the non-exposed region corresponding to the land with a dilute alkaline aqueous solution. As the developing method, for example, a spray method, a shower method or the like is used, and as the dilute alkaline aqueous solution, for example, a 0.5 to 5% by mass sodium carbonate aqueous solution can be used. Next, the developed coating film is flexibly subjected to a thermosetting treatment (post-cure) at 120 ° C. to 180 ° C. for 20 to 80 minutes using a heating device (for example, a hot air circulation type dryer or the like). An insulating film (solder resist film) having a desired pattern can be formed on the printed wiring board.

Next, examples of the present invention will be described, but the present invention is not limited to these examples as long as the gist of the present invention is not exceeded.

Examples 1 to 7, Comparative Examples 1 to 3
Each component shown in Table 1 below is blended in the blending ratio shown in Table 1 below, mixed and dispersed at room temperature using three rolls, and the photosensitive materials used in Examples 1 to 7 and Comparative Examples 1 to 3 are used. A sex resin composition was prepared. Then, the prepared photosensitive resin composition was applied as follows to prepare a test sample. The numbers in the blending amount in Table 1 below indicate parts by mass unless otherwise specified. In addition, the blanks in Table 1 below mean that there is no compounding.

(A) Carboxyl group-containing photosensitive resin / synthetic resin A
In a 500 mL separable flask equipped with a stirrer and a reflux cooling tube, 86.45 g of diethylene glycol monoethyl ether acetate (hereinafter referred to as “EDGAC”) and 8-ethyl octadecanedic acid (Okamura Oil Co., Ltd.) under a nitrogen / air (2: 1) atmosphere. SB-20 Co., Ltd.) 26.54 g (6.3 parts by mass), 45.35 g of behenic acid (10.7 parts by mass), 9.71 g of stearic acid (2.3 parts by mass), 14.36 g of acrylic acid (by mass). 3.4 parts by mass), 0.65 g (0.1 parts by mass) of triphenylphosphine (TPP), 0.43 g (0.1 parts by mass) of methoxyhydroquinone (MEHQ), and nitrogen / air (0.1 parts by mass) in the reaction vessel. 2: 1) was blown at 0.3 mL / sec and heated and stirred at 110 ° C. until it was dissolved. Separately, 137.65 g (32.6 parts by mass) of a biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 265 to 285 g / eq) is heated to 80 ° C. in 59.8 g of an EDGAC solvent. The mixture was uniformly dissolved, placed in the flask, heated and stirred at 115 ° C. for 15 to 17 hours, and reacted until the acid value of the reaction solution became 6 mgKOH / g or less. To this reaction product, 42.23 g (9.9 parts by mass) of hydrogenated trimellitic acid anhydride (Mitsubishi Gas Chemical Company, HTMAn) was further added, and the mixture was stirred at 100 ° C. for 2 to 3 hours under an air atmosphere. It was confirmed by FT-IR (infrared spectrophotometer) that the acid anhydride had disappeared. As a result, a synthetic resin A having a solid content (resin content) of 65% by mass and an acid value of 85 mgKOH / g shown in Table 1 below was obtained.

SP-4621: Polybasic acid-modified epoxy having a structure obtained by reacting at least a part of the epoxy group of the cresol novolak type epoxy resin with acrylic acid to obtain epoxy acrylate and reacting the generated hydroxyl group with polybasic acid. Acrylate, solid content (resin content) 65% by mass, Showa Denko Co., Ltd.
ZAR-2000: A polybasic acid-modified epoxy having a structure obtained by reacting at least a part of the epoxy group of a bisphenol F type epoxy resin with an acrylic acid to obtain an epoxy acrylate and reacting the generated hydroxyl group with a polybasic acid. Acrylate, solid content (resin content) 65% by mass, Nippon Kayaku Co., Ltd.
ZCR-1569H: A polybasic acid-modified epoxy acrylate having a structure obtained by reacting at least a part of the epoxy group of a biphenyl type epoxy resin with acrylic acid to obtain an epoxy acrylate and reacting the generated hydroxyl group with a polybasic acid. , Solid content (resin content) 65% by mass, Nippon Kayaku Co., Ltd.

(B) Compound of cyanuric acid and metal-Starfine F-10: Zinc cyanurate, average particle size measured by laser method is 1.7 μm, columnar particles, Nissan Chemical Industries, Ltd.

(C) Photopolymerization Initiator NCI-831: (9-ethyl-6-nitro-9H-carbazole-3-yl) (4-((1-methoxypropane-2-yl) oxy) -2-methylphenyl) ) Metanon O-acetyloxym (oxime-based photopolymerization initiator), ADEKA CORPORATION.
Omnirad 369: 2-Benzyl-2- (dimethylamino) -1- (4-morpholinophenyl) -1-butanone (α-aminoalkylphenone-based photopolymerization initiator), IGM Resins B.I. V. Company.

(D) Reactive diluent, DPCA-60: Nippon Kayaku Co., Ltd.
(E) Epoxy compound YX-4000HK: Mitsubishi Chemical Corporation.

Colorant Lionol Blue FG-7351: Toyo Ink Mfg. Co., Ltd.
・ MA14: Mitsubishi Chemical Corporation.
Matting agent Acemat OK-212: Evonik.
-RHC-730: Dainichiseika Kogyo Co., Ltd.
Flame Retardant / Exorit OP-935: Clariant Japan.
Additives / Melamine: Nissan Chemical Industries, Ltd.
・ DICY-7: Mitsubishi Chemical Corporation.
Defoamer KS-66: Shin-Etsu Chemical Co., Ltd.
Non-reactive diluent / EDGAC: Sanyo Kaseihin Co., Ltd.

Adhesion-imparting agent ・ 2MBO: Conventional adhesion-imparting agent, Aldrich Chemical.

Specimen manufacturing process Flexible printed wiring with a 25 μm-thick polyimide film (Toray DuPont Co., Ltd., “Kapton 100H”) provided with a comb-shaped circuit pattern with a conductor (copper foil) thickness of 18 μm, a line width of 100 μm, and a space width of 100 μm. After surface treatment with a 3% by mass aqueous solution of sulfuric acid on the plate, the photosensitive resin composition prepared as described above was applied by a screen printing method so that the DRY film thickness on the conductor was 20 μm. Then, in the BOX furnace, pre-drying was performed at 70 ° C. for 20 minutes. After pre-drying, a negative film (photomask) having a translucent pattern other than the land of the circuit pattern is adhered to the applied photosensitive resin composition, and an exposure apparatus (ORC Manufacturing Co., Ltd., "HMW-680GW") is adhered. ”) And irradiated with ultraviolet rays (wavelength 300 to 400 nm) of 400 mJ / cm ² . After irradiation with ultraviolet rays, development was carried out at a spray pressure of 0.1 MPa for 60 seconds using a 1% by mass sodium carbonate aqueous solution at 30 ° C. After development, a cured coating film was formed by heat-curing (post-curing) at 150 ° C. for 60 minutes in a BOX furnace to prepare a test piece for evaluation.

The evaluation items are as follows.
(1) Gold plating resistance Using commercially available electroless nickel plating baths and electroless gold plating baths, plating was performed under the conditions of nickel 5 μm and gold 0.03 μm. After evaluating the presence or absence of peeling of the cured coating film and the presence or absence of plating soaking, the presence or absence of peeling of the cured coating film from the substrate was evaluated by tape peeling. The judgment criteria are as follows.
⊚: No peeling occurs in the cured coating film after tape peeling.
◯: After tape peeling, the cured coating film was slightly peeled off.
Δ: There is some penetration after plating.
X: After plating, the cured coating film has peeled off.

(2) Storage stability (thickness thickening rate)
The photosensitive resin composition prepared as described above was subjected to viscosity measurement (25 ° C.) with a tuning fork type vibration viscometer, and the thickening rate after 50 ° C. for 7 days was determined in a constant temperature bath. The judgment criteria are as follows.
◯: thickening rate less than 10% Δ: thickening rate 10% or more and less than 20% ×: thickening rate 20% or more

(3) Alkaline developability The time required to develop the coating film after pre-drying in the above-mentioned test piece preparation step at a spray pressure of 0.2 MPa (using a 1% by mass sodium carbonate developer at 30 ° C.). Was used as a break point, and the time was measured. The judgment criteria are as follows.
◯: Breakpoint less than 30 seconds Δ: Breakpoint 30 seconds or more and less than 60 seconds ×: Breakpoint 60 seconds or more

(4) Heat resistance The cured coating film of the test piece after the gold plating treatment is immersed in a solder bath at 260 ° C. for 30 seconds according to the test method of JIS C-6481, and then the peeling test with cellophane tape is set as one cycle. The state of the cured coating film after repeating twice was visually observed and evaluated according to the following criteria.
◯: No abnormality was observed in the cured coating film after repeating 2 cycles.
X: Abnormalities such as peeling are observed in the cured coating film after repeating 2 cycles.

The evaluation results are shown in Table 1 below.

As shown in Table 1 above, (A) a carboxyl group-containing photosensitive resin, (B) a compound of cyanuric acid and a metal (zinc cyanurate in the examples), (C) a photopolymerization initiator, and (D). ) In the photosensitive resin compositions of Examples 1 to 7 containing the reactive diluent and the epoxy compound (E), even if the DRY film thickness is as thin as 20 μm, the metal plating resistance and heat resistance are improved. It was also excellent in storage stability of the photosensitive resin composition and in alkali developability of the photocured product of the photosensitive resin composition. In particular, from Examples 1 to 3 and Example 7, when zinc cyanurate is contained in an amount of about 0.5 parts by mass or more and about 10 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin, the carboxyl group-containing photosensitive resin is contained. Compared with the case where about 15 parts by mass of zinc cyanurate was contained with respect to 100 parts by mass, the storage stability and the alkali developability were further improved.

On the other hand, as shown in Table 1 above, in Comparative Examples 1 and 3 in which zinc cyanurate was not blended, good gold plating resistance could not be obtained when the DRY film thickness was reduced to 20 μm. Further, in Comparative Example 2 in which mercaptobenzoxazole, which is a conventional adhesion-imparting agent, was used instead of zinc cyanurate, when the DRY film thickness was reduced to 20 μm, good gold plating resistance, heat resistance and heat resistance were obtained. Alkaline developability could not be obtained.

In the present invention, various photosensitive resin compositions can be obtained, which can form a cured product having excellent gold plating resistance without impairing basic properties such as storage stability, alkali developability, and heat resistance. It has high utility value in the field of printed wiring boards for mounting electronic components.

Claims (9)

Photosensitivity containing (A) a carboxyl group-containing photosensitive resin, (B) a compound of cyanuric acid and a metal, (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy compound. Sex resin composition. The photosensitive resin composition according to claim 1, wherein the compound of (B) cyanuric acid and a metal is contained in an amount of 0.10 parts by mass or more and 14 parts by mass or less with respect to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin. .. The photosensitive resin composition according to claim 1 or 2, wherein the compound (B) cyanuric acid and the metal is columnar particles. The photosensitive resin composition according to any one of claims 1 to 3, wherein the average particle size of the compound (B) cyanuric acid and the metal measured by a laser method is 0.5 μm or more and 5.0 μm or less. .. The photosensitive resin composition according to any one of claims 1 to 4, wherein the compound of (B) cyanuric acid and the metal is zinc cyanurate. The (A) carboxyl group-containing photosensitive resin has a radically polymerizable unsaturated monocarboxylic acid in at least a part of the epoxy group of the polyfunctional epoxy resin having two or more epoxy groups in one molecule of (A-1). A polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin having a structure obtained by reacting the generated hydroxyl group with a polybasic acid and / or a polybasic acid anhydride by reacting to obtain an unsaturated monocarboxylic oxide epoxy resin and (A-2) A polyfunctional epoxy resin having two or more epoxy groups in one molecule and at least one linear or branched aliphatic carboxylic acid having 10 or more carbon atoms per carboxyl group. An acid-modified long-chain hydrocarbon structure having a structure obtained by adding a polybasic acid and / or a polybasic acid anhydride to an unsaturated carboxylic oxide epoxy resin which is a reaction product with a radically polymerizable unsaturated monocarboxylic acid. The photosensitive resin composition according to any one of claims 1 to 5, which is at least one selected from the group consisting of the contained epoxy resin. The photosensitive resin composition according to any one of claims 1 to 6, wherein the reactive diluent (D) contains caprolactone-modified (meth) acrylate. The photocured product of the photosensitive resin composition according to any one of claims 1 to 7. A printed wiring board having a photocurable film of the photosensitive resin composition according to any one of claims 1 to 7.