JP2020160146A - Photosensitive resin composition - Google Patents

Abstract

To provide a photosensitive resin composition that gives a cured product having excellent flexibility (plasticity) and matte effect while having excellent insulation reliability, and has excellent coatability.SOLUTION: A photosensitive resin composition contains (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) an epoxy compound, (D) a carboxyl group-modified silicone oil, (E) a reactive diluent.SELECTED DRAWING: None

Description

The present invention relates to a photosensitive resin composition which has excellent printability, has a matted surface and flexibility, and can obtain a cured product having insulation reliability.

The flexible printed wiring board is a printed wiring board in which a pattern of a conductor circuit is formed on a flexible substrate. Electronic components are mounted by soldering on the soldering lands of the conductor circuit pattern. The circuit portion excluding the soldering land is covered with an insulating film which is a cured film of the photosensitive resin composition.

From the viewpoint of hiding power and the like, the insulating coating may have a matte surface that roughens (mattes) the surface to reduce the gloss. In order to roughen the surface of the insulating film, a fine particle filler may be blended in the photosensitive resin composition. Further, in order to prevent uneven coating of the insulating coating and deterioration of the appearance, the photosensitive resin composition is required to have coatability. Further, as electronic devices have become smaller and their internal structures have become more complicated, flexible printed wiring boards are required to have excellent flexibility.

As a composition for roughening the surface to reduce gloss and obtaining an insulating film having flexibility (flexibility), for example, (A) two or more unsaturated double bonds and one or more unsaturated double bonds in one molecule. Photosensitive prepolymer having a carboxyl group of, (B) photopolymerization initiator, (C) diluent, (D) epoxy compound, (E) polybutadiene having one or more internal epoxide groups in one molecule, and ( F) A composition containing polyurethane particles is disclosed (Patent Document 1).

However, when a fine particle filler such as polyurethane particles is mixed in the photosensitive resin composition in order to roughen the surface of the insulating film formed on the circuit board as in the composition of Patent Document 1, the fine particles are formed. Coarse particles contained in a part of the filler may cause surface defects such as excessive unevenness in the insulating film. On the other hand, when the fine particle filler is further miniaturized, it becomes necessary to increase the blending amount of the fine particle filler in order to roughen the surface and reduce the gloss, and the photosensitive resin composition is coated on the substrate. In some cases, the property was reduced and the flexibility (flexibility) of the insulating film could not be obtained.

Further, when the blending amount of the fine particle filler is suppressed, the flexibility (flexibility) of the insulating film tends to be obtained, but the surface thereof may not be sufficiently roughened.

JP-A-2002-293882

In view of the above circumstances, the present invention can obtain a cured product having excellent insulation reliability while having excellent flexibility (flexibility) and matting effect, and is photosensitive with excellent coatability. An object of the present invention is to provide a resin composition, a cured product of the photosensitive resin composition, and a flexible printed wiring board having the cured product.

The gist of the structure of the present invention is as follows.
[1] (A) Carboxylic group-containing photosensitive resin, (B) Photopolymerization initiator, (C) Epoxy compound, (D) Carboxylic acid-modified silicone oil, and (E) Reactive diluent. The photosensitive resin composition contained.
[2] The photosensitive resin composition according to [1], wherein the carboxyl group equivalent of the (D) carboxyl group-modified silicone oil is 500 g / mol or more and 5000 g / mol or less.
[3] The photosensitive resin composition according to [1] or [2], wherein the carboxyl group equivalent of the (D) carboxyl group-modified silicone oil is 1000 g / mol or more and 3000 g / mol or less.
[4] The (D) carboxyl group-modified silicone oil is contained in an amount of 5.0 parts by mass or more and 13 parts by mass or less with respect to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin [1] to [3]. The photosensitive resin composition according to any one of the above.
[5] The photosensitive resin composition according to any one of [1] to [4], which further contains (F) silicone particles.
[6] The photosensitive resin composition according to [5], wherein the (F) silicone particles have a cumulative volume percentage of 50% by volume and a particle diameter (D50) of 0.50 μm or more and 2.0 μm or less.
[7] The cured product of the photosensitive resin composition according to any one of [1] to [6].
[8] A flexible printed wiring board having the cured product according to [7].

According to the aspect of the photosensitive resin composition of the present invention, by containing the above components (A) to (E), it has excellent flexibility (flexibility) and a matting effect, and is excellent in insulation reliability. A cured product can be formed, and a photosensitive resin composition having excellent coatability can be obtained.

According to the aspect of the photosensitive resin composition of the present invention, the surface of the cured product is roughened by the carboxyl group equivalent of (D) carboxyl group-modified silicone oil of 1000 g / mol or more and 3000 g / mol or less. The matte effect is further improved.

According to the aspect of the photosensitive resin composition of the present invention, the (D) carboxyl group-modified silicone oil is 5.0 parts by mass or more and 13 parts by mass or less with respect to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin. When it is contained, the surface of the cured product is roughened to further improve the matting effect, and the coating film of the photosensitive resin composition can be imparted with tackiness.

According to the aspect of the photosensitive resin composition of the present invention, the surface of the cured product is further roughened by further containing the (F) silicone particles, and the matting effect is further improved.

Next, the photosensitive resin composition of the present invention will be described below. The photosensitive resin composition of the present invention comprises (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) an epoxy compound, (D) a carboxyl group-modified silicone oil, and (E). Contains a reactive diluent.

(A) Carboxylic 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 a carboxyl group-containing photosensitive resin, (A-1) a radically polymerizable unsaturated monocarboxylic acid is reacted with at least a part of the epoxy groups of a 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) At least a part of the epoxy groups of an epoxy resin having two or more epoxy groups in one molecule has 5 or more carbon atoms per carboxyl group. It is obtained by reacting a long-chain fatty acid-modified unsaturated monocarboxylic oxide epoxy resin obtained by reacting at least one kind of fatty acid to a radically polymerizable unsaturated monocarboxylic acid with a polybasic acid or a polybasic acid anhydride. Examples thereof include a polybasic acid-modified long-chain fatty acid-modified unsaturated monocarboxylic oxide epoxy resin having a structure (hereinafter, may be referred to as “A-2 resin”).

A-1 resin A-1 resin contains acrylic acid or methacrylic acid (hereinafter referred to as "(meth) acrylic acid") in at least a part of the epoxy groups of a polyfunctional epoxy resin having two or more epoxy groups in one molecule. In some cases, a radically polymerizable unsaturated monocarboxylic acid such as) is reacted to obtain an unsaturated monocarboxylic oxide epoxy resin such as epoxy (meth) acrylate, and the generated hydroxyl group is further subjected to polybasic acid or polybase. Examples thereof include a polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin such as a polybasic acid-modified epoxy (meth) acrylate obtained by reacting an acid anhydride.

The chemical structure of the polyfunctional epoxy resin is not particularly limited as long as it is a bifunctional or higher functional 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, more preferably 2000 g / eq, further preferably 1000 g / eq, and particularly preferably 500 g / eq. On the other hand, the lower limit of the epoxy equivalent of the polyfunctional epoxy resin is preferably 100 g / eq, and particularly preferably 200 g / eq. Examples of the polyfunctional epoxy resin include biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, ε-caprolactone modified epoxy resin, and bisphenol A type epoxy. Resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin such as bisphenol AD type epoxy resin, cresol novolac type epoxy resin such as о-cresol novolac type, bisphenol A novolac type epoxy resin, cyclic aliphatic epoxy resin, glycidyl ester type Examples thereof include epoxy resins, glycidylamine-type epoxy resins, heterocyclic epoxy resins, bisphenol-modified novolak-type epoxy resins, and polyfunctional-modified novolak-type epoxy resins. Further, halogen atoms such as Br and Cl may be introduced into these resins. These epoxy resins may be used alone or in combination of two or more.

The radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and examples thereof include (meth) acrylic acid, crotonic acid, tiglic acid, angelic acid, and cinnamic acid. Of these, (meth) acrylic acid is preferable because it is easily available and handled. These radically polymerizable unsaturated monocarboxylic acids may be used alone or in combination of two or more.

The method for reacting the polyfunctional epoxy resin with the radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and for example, the polyfunctional epoxy resin and the radically polymerizable unsaturated monocarboxylic acid are mixed in a diluent such as an organic solvent. Examples thereof include a method of melting, stirring, and heating at a predetermined temperature.

The carboxyl group of the polybasic acid and / or the polybasic acid anhydride is added to the hydroxyl group generated by the reaction of the polyfunctional epoxy resin with the radically polymerizable unsaturated monocarboxylic acid, thereby causing a radically polymerizable unsaturated monocarboxylic acid. A free carboxyl group is introduced into the epoxy oxide resin. The chemical structure of the polybasic acid and the polybasic acid anhydride is not particularly limited, and either saturated or unsaturated can be used. Examples of polybasic acids include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-. Tetrahydrophthalates such as ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, hexahydro such as 4-ethylhexahydrophthalic acid Examples thereof include tetrahydrophthalic acids such as phthalic acids, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid and methylendomethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid and diglycolic acid. Examples of the polybasic acid anhydride include the above-mentioned anhydrides of various polybasic acids. These compounds may be used alone or in combination of two or more.

The method for reacting the radically polymerizable unsaturated monocarboxylic oxide epoxy resin with the polybasic acid and / or the polybasic acid anhydride is not particularly limited, and for example, the radically polymerizable unsaturated monocarboxylic oxide epoxy resin and the polybasic acid are not particularly limited. And / or a method in which the polybasic acid anhydride is dissolved in a diluent such as an organic solvent, stirred, and heated at a predetermined temperature can be mentioned.

The above-mentioned polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin can also be used as a carboxyl group-containing photosensitive resin, but one or more radicals may be part of the carboxyl groups of the above-mentioned polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin. A polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxide epoxy resin obtained by further adding a radically polymerizable unsaturated group, which is obtained by an addition reaction of a compound having a polymerizable unsaturated group and an epoxy group, may be used. In the polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxide epoxy resin to which a radically polymerizable unsaturated group is further added, a radically polymerizable unsaturated group is further introduced into the side chain of the polybasic acid modified unsaturated monocarboxylic oxide epoxy resin. Has a chemical structure that is Therefore, as compared with the above-mentioned polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin, the polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxide epoxy resin to which a radically polymerizable unsaturated group is further added is more photosensitive. It is an improved resin.

Examples of the compound having one or more radically polymerizable unsaturated groups and an epoxy group include glycidyl compounds. Examples of the glycidyl compound include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether, pentaerythritol trimethacrylate monoglycidyl ether and the like. It should be noted that one molecule may have one glycidyl group, or a plurality of glycidyl groups may be contained. Further, the above-mentioned compound having one or more radically polymerizable unsaturated groups and an epoxy group may be used alone or in combination of two or more.

The method for reacting the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin with a compound having one or more radically polymerizable unsaturated groups and an epoxy group is not particularly limited, and for example, the polybasic acid-modified unsaturated group is used. Examples thereof include a method in which a saturated monocarboxylic oxide epoxy resin, one or more radically polymerizable unsaturated groups, and a compound having an epoxy group are dissolved and stirred in a diluent such as an organic solvent, and heated at a predetermined temperature.

A-2 resin The A-2 resin has at least a part of the epoxy groups of the polyfunctional epoxy resin having two or more epoxy groups in one molecule, and at least five or more carbon atoms per carboxyl group. It is obtained by reacting one kind of fatty acid with a radically polymerizable unsaturated monocarboxylic acid to obtain a long-chain fatty acid-modified unsaturated monocarboxylic oxide epoxy resin, and reacting the produced hydroxyl group with a polybasic acid or its anhydride. Examples thereof include a polybasic acid-modified long-chain fatty acid-modified unsaturated monocarboxylic oxide epoxy resin.

Examples of the polyfunctional epoxy resin used for synthesizing the A-2 resin include the same polyfunctional epoxy resins as the various polyfunctional epoxy resins that can be used for the A-1 resin. Of these, a biphenyl type epoxy resin and a biphenyl aralkyl type epoxy resin are preferable. The radically polymerizable unsaturated monocarboxylic acid used for the synthesis of the A-2 resin includes, for example, the same radically polymerizable unsaturated monocarboxylic acid as the various radically polymerizable unsaturated monocarboxylic acids that can be used for the A-1 resin. Can be mentioned. The polybasic acid or polybasic acid anhydride used in the synthesis of the A-2 resin includes, for example, the same polybasic acid or the same polybasic acid anhydride as various polybasic acids or polybasic acid anhydrides that can be used in the A-1 resin. Polybasic acid anhydride can be mentioned.

A fatty acid (long-chain fatty acid) having 5 or more carbon atoms per carboxyl group reacts with an epoxy group of an epoxy resin having two or more epoxy groups in one molecule, and the resin is derived from the above fatty acid. By introducing the long-chain fatty acid structure, the flexibility (flexibility) and insulation reliability of the cured product of the photosensitive resin composition can be improved. The fatty acid having 5 or more carbon atoms per carboxyl group is not particularly limited, and either saturated or unsaturated fatty acid can be used, and either linear or branched fatty acid can be used. Examples of the fatty acid include a monobasic acid having 5 or more carbon atoms and a diprotic acid having 10 or more carbon atoms. From the viewpoint of the balance between flexibility and tackiness, the monobasic acid and the dibasic acid are Linear is preferable.

Further, while introducing the long-chain hydrocarbon structure into the epoxy resin, the different epoxy groups of the epoxy resin are bonded to each other via the long-chain fatty acid, so that the rigid skeleton of the epoxy resin is derived from the long-chain fatty acid. The structure is cross-linked by covalent bonds in the highly flexible long-chain hydrocarbon skeleton. The long-chain fatty acid preferably contains at least one dibasic acid because the structure crosslinked with the long-chain hydrocarbon skeleton contributes to the improvement of the flexibility of the cured product.

Further, the flexibility of the cured product can be further improved by introducing a larger amount of highly flexible long-chain hydrocarbon skeleton derived from long-chain fatty acids, and the number of carbon atoms per carboxyl group described above is 5. By using a single base having 5 or more carbon atoms per carboxyl group in combination with the above dibasic acid, a long-chain fatty acid, a radically polymerizable unsaturated monocarboxylic acid, and a polyfunctional epoxy resin can be used. The molecular weight of the reaction product can be appropriately controlled while improving the composition ratio of the components derived from long-chain fatty acids. By appropriately controlling the molecular weight of the reaction product, the dryness to the touch (tackiness) of the coating film after drying, the solubility in an alkaline developer (that is, the developability), and the sensitivity are surely balanced. Can be improved. In addition, the combined use of monobasic acid and dibasic acid contributes to further improvement of insulation reliability.

The number of carbon atoms per carboxyl group of the fatty acid is 5 or more, preferably 7 or more, from the viewpoint of imparting flexibility to the cured product. On the other hand, the upper limit of the number of carbon atoms per carboxyl group is not particularly limited, but is preferably 24 or less, particularly preferably 22 or less, from the viewpoint of maintaining developability.

Specific examples of fatty acids having 5 or more carbon atoms per carboxyl group include palmitic acid (C5), hexadecanoic acid (C6), heptanic acid (C7), and capric acid (C8) as monobasic acids. Nonanoic acid (C9), Capric acid (C10), Undecanoic acid (C11), Lauric acid (C12), Tridecanoic acid (C13), Myristic acid (C14), Pentadecanoic acid (C15), Palmitic acid (Hexadecanoic acid: C16) , Margaric acid (heptadecanoic acid: C17), stearic acid (C18), isostearic acid (C18), tubercross stearic acid (C19), arachidic acid (C20), behenic acid (C22), tricosyl acid (C23), tetracosanoic acid (C24) and the like.

Examples of the dibasic acid of the fatty acid having 5 or more carbon atoms per carboxyl group include sebacic acid (C10), eikosan diic acid (C20), ethyl octadecane diic acid (C20), eikosadien diic acid (C20), and vinyl. Dimeric of unsaturated fatty acids such as octadecaene diic acid (C20), dimethyleicosadiene diic acid (C22), dimethyleicosane diic acid (C22), diphenylhexadecan diic acid (C28), oleic acid (C18) Examples thereof include C36 dimer acid produced by a chemical reaction, hydrogenated C36 dimer acid obtained by adding hydrogen to the olefinic double bond of the dimer acid, and the like.

Further, in synthesizing the polybasic acid-modified long-chain fatty acid-modified unsaturated monocarboxylic oxide epoxy resin obtained as described above, as an organic solvent for reacting the produced hydroxyl group with a polybasic acid or a polybase anhydride. Examples include diols such as glycols such as diethyl diglycol (DEDG).

The acid value of the various carboxyl group-containing photosensitive resins described above is not particularly limited, but the lower limit of the acid value is preferably 30 mgKOH / g and particularly preferably 40 mgKOH / g from the viewpoint of reliable alkaline development. 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, and 150 mgKOH / g from the viewpoint of contributing to the improvement of the insulation reliability of the cured product. g is particularly preferable.

The mass average molecular weight of the various carboxyl group-containing photosensitive resins described above is not particularly limited, but the lower limit thereof is preferably 5000, particularly preferably 7000, from the viewpoint of toughness and tackiness of the cured product. On the other hand, the upper limit of the mass average molecular weight is preferably 100,000, particularly preferably 50,000, from the viewpoint of smooth alkali developability. 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.

Examples of commercially available photosensitive resins containing various carboxyl groups include ZAR-2000, ZFR-1122, FLX-2089, ZCR-1569H, ZCR-1601H (Nippon Kayaku Co., Ltd.) and the like. Can be mentioned. The above-mentioned various carboxyl group-containing photosensitive resins may be used alone or in combination of two or more.

(B) Photopolymerization initiator The photopolymerization initiator is not particularly limited as long as it is generally used, and is, for example, (9-ethyl-6-nitro-9H-carbazole-3-yl) [4-yl]. (2-Methyl-1-methylethoxy-2-methylphenyl]-, o-acetyloxime, 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], etanone 1 -[9-Ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -1- (0-acetyloxime), 2- (acetyloxyiminomethyl) thioxanthene-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-methoxypropan-2-yl) oxy) -2-methylphenyl) Oxime ester-based photopolymerization initiator such as methanone O-acetyloxime, 2-benzyl- Α-Aminoalkylphenone-based light such as 2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one Polymerization initiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy -2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-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-tertiary butyl anthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethyl Thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthio Xantone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenonedimethylketal, P-dimethylaminobenzoic acid ethyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenyl Examples thereof include phosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide and the like. These photopolymerization initiators may be used alone or in combination of two or more. Of these, an oxime ester-based photopolymerization initiator is preferable because of its excellent photosensitivity.

The content of the photopolymerization initiator is not particularly limited, but is preferably 0.1 part by mass or more and 20 parts by mass with respect to 100 parts by mass (solid content, the same applies hereinafter) of the carboxyl group-containing photosensitive resin, and is 0.5% by mass. More than 10 parts by mass is particularly preferable.

(C) Epoxy compound The epoxy compound is for increasing the crosslink density of the cured product to obtain a cured product such as a cured coating film having sufficient strength. Examples of the epoxy compound include an epoxy resin. Examples of the epoxy resin include an epoxy resin that can be used for preparing the above-mentioned (A) carboxyl group-containing photosensitive resin. Specifically, for example, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, ε-caprolactone modified epoxy resin, bisphenol A type epoxy resin, bisphenol Phenol novolac type epoxy resin such as F type epoxy resin and bisphenol AD type epoxy resin, cresol novolac type epoxy resin such as о-cresol novolac type, bisphenol A novolac type epoxy resin, cyclic aliphatic epoxy resin, glycidyl ester type epoxy resin, Examples thereof include glycidylamine type epoxy resin, heterocyclic epoxy resin, bisphenol modified novolak type epoxy resin, and polyfunctional modified novolak type epoxy resin. These may be used alone or in combination of two or more.

The content of the epoxy compound is not particularly limited, but is 5.0 parts by mass or more and 80 parts by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin from the viewpoint of obtaining sufficient strength without impairing the flexibility of the cured coating film. It is preferably 20 parts by mass or less, and particularly preferably 20 parts by mass or more and 60 parts by mass or less.

(D) Carboxylic Acid-Modified Silicone Oil Carboxylic acid-modified silicone oil can impart excellent flexibility (flexibility), matting effect due to roughening, and insulation reliability to the cured product, and is also photosensitive. The coatability of the silicone resin composition can be improved. During the alkaline development process performed after the coating film of the photosensitive resin composition is exposed, the carboxyl group-modified silicone oil is dissolved by an alkaline developer to roughen the surface of the cured product and matte the cured product. It is thought that this is because the effect is given.

The carboxyl group equivalent of the carboxyl group-modified silicone oil is not particularly limited, but the lower limit thereof is preferably 500 g / mol, more preferably 1000 g / mol, and particularly preferably 1300 g / mol from the viewpoint of preventing a decrease in compatibility. On the other hand, the upper limit of the carboxyl group equivalent of the carboxyl group-modified silicone oil is preferably 5000 g / mol, more preferably 3000 g / mol, and particularly preferably 2500 g / mol from the viewpoint of surely obtaining a matting effect by roughening.

The content of the carboxyl group-modified silicone oil is not particularly limited, but the lower limit is 1.0 with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin from the viewpoint of surely obtaining a matting effect by roughening. By mass is preferable, 3.0 parts by mass is more preferable, and 5.0 parts by mass is particularly preferable. On the other hand, the upper limit of the content of the carboxyl group-modified silicone oil is 30 parts by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin from the viewpoint of further imparting tackiness to the coating film of the photosensitive resin composition. Is preferable, 20 parts by mass is more preferable, and 13 parts by mass is particularly preferable.

Examples of the carboxyl group-modified silicone oil include a bi-terminal carboxyl group-introduced silicone oil (for example, "X-22-162C", Shin-Etsu Chemical Co., Ltd.) and a side chain carboxyl group-introduced silicone oil (for example, "" "X-22-3701E", Shin-Etsu Chemical Co., Ltd.), Mixed silicone oil of both terminal carboxyl group introduction type and non-functional type (for example, "X-22-3710", Shin-Etsu Chemical Co., Ltd.), carboxyl group Examples thereof include silicone oil having an equivalent amount of 750 g / mol (“BY16-750”, Toray Dow Corning Co., Ltd.), silicone oil having a carboxyl group equivalent of 3500 g / mol (“BY16-880”, Toray Dow Corning Co., Ltd.), and the like.

(E) Reactive Diluent The reactive diluent is, for example, a photopolymerizable monomer and is a compound having at least one, preferably two or more polymerizable double bonds per molecule. The reactive diluent is used to reinforce the photocuring of the photosensitive resin composition during the exposure treatment to obtain a cured product having sufficient acid resistance, heat resistance, alkali resistance and the like. Examples of the reactive diluent include a monofunctional (meth) acrylate monomer and a bifunctional or higher functional (meth) acrylate monomer. Examples of the (meth) acrylate monomer include hydroxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, diethylene glucol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylic rate, and stearyl (meth). ) Monofunctional (meth) acrylate compounds such as acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, neopentyl Glycoldi (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, dicyclopentanyldi (meth) acrylate, ethylene oxide-modified phosphoric acid Bifunctional (meth) acrylate compounds such as di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethyl propantri (meth) acrylate, ditrimethylolpropantetra (meth) acrylate, Dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropanetri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate, Examples thereof include trifunctional or higher functional (meth) acrylate compounds such as dipentaerythritol hexa (meth) acrylate and ε-caprolactane-modified dipentaerythritol hexa (meth) acrylate. These may be used alone or in combination of two or more.

The content of the reactive diluent is not particularly limited, but is preferably 5.0 parts by mass or more and 80 parts by mass or less, and particularly 20 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin. preferable.

In the present invention, in addition to the above components (A) to (E), (F) silicone particles may be further blended, if necessary. By blending the silicone particles, the surface of the cured product is roughened and the matting effect is further improved while imparting flexibility (flexibility).

The average particle size of the silicone particles is not particularly limited, but for example, the lower limit of the particle size (D50) having a cumulative volume percentage of 50% by volume contributes to the improvement of the matting effect by roughening and the coatability. 0.30 μm is preferable, and 0.50 μm is particularly preferable, from the viewpoint of preventing a decrease in the amount of particles. On the other hand, the upper limit of the particle diameter (D50) in which the cumulative volume percentage of the silicone particles is 50% by volume is preferably 3.0 μm from the viewpoint of preventing surface defects such as excessive unevenness from occurring in the cured product. 0.0 μm is particularly preferable. The particle size (D100) having a cumulative volume percentage of 100% by volume is not particularly limited, but is preferably 8.0 μm or less from the viewpoint of preventing surface defects such as excessive unevenness in the cured product. 5.0 μm or less is particularly preferable. The lower limit of the particle diameter (D100) having a cumulative volume percentage of 100% by volume is preferably as small as possible, and examples thereof include 4.0 μm. The average particle size is a value measured by the laser diffraction / scattering method.

The chemical structure of the silicone particles is not particularly limited, but for example, the following general formula (1)
RSiO _3/2 (1)
(In the formula, R is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms.) Polyorganosylsesquioxane having a unit represented by the unit, or a main component (for example, silicone). Examples of the content (content of 80% by mass or more in the powder) include silicone particles containing polyorganosylsesquioxane having a unit represented by the above general formula (1). Examples of R include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, undecyl group, dodecyl group, tetradecyl group, pentadecyl group, hexadecyl group and heptadecyl group. , Octadecyl group, nonadecil group and other alkyl groups; vinyl group and other alkenyl groups; phenyl group, trill group, naphthyl group and other aryl groups; benzyl group, phenethyl group and other aralkyl groups; cyclopentyl group, cyclohexyl group, cycloheptyl group Cycloalkyl groups such as; unsubstituted or substituted amino groups; monovalent hydrocarbon groups substituted with halogen atoms, acryloyloxy groups, methacryloyloxy groups, epoxy groups, glycidoxy groups, mercapto groups, carboxyl groups and the like. .. Examples of the substituted amino group include an amino group substituted with an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms. Among these polyorganosylsesquioxane, an unsubstituted hydrocarbon group having 1 to 6 carbon atoms of R is preferable, and polymethylsilsesquioxane is particularly preferable.

（式中、Ｒ^１、Ｒ^２は、それぞれ独立して、非置換または置換の炭素原子数１〜２０の１価の炭化水素基である。）で表される構造を有するゴム状のシリコーン粒子でもよい。ここで、非置換または置換の炭素原子数１〜２０の１価の炭化水素基Ｒ^１、Ｒ^２としては、上記一般式（１）のＲについて例示した１価の炭化水素基が挙げられる。これらのうち、疎水性の点から、Ｒ^１、Ｒ^２は、それぞれ、独立して、メチル基、エチル基が好ましい。また、一般式（２）のシリコーンパウダーの分子構造は、特に制限されず、例えば、直鎖状、部分分岐した直鎖状、分岐鎖状、樹枝状（デンドリマー状）等が挙げられる。 Further, the silicone particles are replaced with the polyorganosyl sesquioxane of the above general formula (1), and the following general formula (2) is used.

(In the formula, R ¹ and R ² are independently substituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms.) Rubber-like silicone particles having a structure represented by the above. It may be. The monovalent hydrocarbon radicals R ^1, R ² an unsubstituted or substituted having 1 to 20 carbon atoms include monovalent hydrocarbon groups exemplified for R in the general formula (1). Of these, from the viewpoint of hydrophobicity, R ¹ and R ² are preferably methyl groups and ethyl groups, respectively. The molecular structure of the silicone powder of the general formula (2) is not particularly limited, and examples thereof include a linear chain, a partially branched linear chain, a branched chain, a dendrimer, and the like.

The content of the silicone particles is not particularly limited, but is preferably 5.0 parts by mass or more and 50 parts by mass or less, preferably 10 parts by mass, from the viewpoint of improving the matting effect by roughening and balancing the coatability and flexibility. More than 30 parts by mass is particularly preferable.

In the present invention, in addition to the above-mentioned components (A) to (F), other components such as a colorant, a flame retardant, various additives, a defoaming agent, a non-reactive diluent and the like are added as needed. , May be blended as appropriate.

The colorant is not particularly limited to pigments, pigments, etc., and any color such as white colorant, blue colorant, green colorant, yellow colorant, purple colorant, black colorant, orange colorant, etc. is colored. Agents can also be used. Examples of the colorant include inorganic colorants such as titanium oxide which is a white colorant and carbon black which is a black colorant, phthalocyanine green which is a green colorant, and phthalocyanine blue and lionol blue which are blue colorants. Examples thereof include phthalocyanine-based and anthraquinone-based organic colorants such as chromoftal yellow, which is a yellow colorant.

The flame retardant is for imparting flame retardancy to the cured product of the photosensitive resin composition. Examples of the flame retardant include a phosphorus-based flame retardant, and an organic phosphate-based flame retardant is preferable. 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 phosphates such as chloropropyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris (tribromophenyl) phosphate, tris (dibromophenyl) phosphate, and tris (tribromoneopentyl) phosphate. Esters; non-halogen aliphatic phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate; triphenyl phosphate, cresyldiphenyl phosphate, dicredylphenyl 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 phosphates such as: aluminum trisdiphenylphosphine, aluminum trismethylethylphosphine, aluminum trisdiphenylphosphine, zinc bisdiphenylphosphine, zinc bismethylethylphosphine, zinc bisdiphenylphosphine, bisdiethyl Metal salts of phosphinic acids such as titanyl phosphine, titanium tetrakisdiphenylphosphine, 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.

Various 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). Examples thereof include a curing catalyst such as polyamine, a reaction accelerator such as a zirconium compound, a thioxogenic agent, and an antioxidant. Examples of the defoaming agent include silicone-based, hydrocarbon-based, and acrylic-based.

The non-reactive diluent is for adjusting the viscosity and drying property of the photosensitive resin composition. Examples of the non-reactive diluent include organic solvents. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexane, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol, cyclohexanol and glycol, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. , Cellosolves, cellosolves such as butylcellosolve, carbitols such as carbitol and butylcarbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, diethylene glycol monomethyl ether acetate, ethyldi Examples thereof include esters such as glycol acetate.

The method for producing the photosensitive resin composition of the present invention is not limited to a specific method. For example, after blending each of the above components in a predetermined ratio, at room temperature (for example, 25 ° C.), a three-roll, ball mill, and sand mill It can be produced by kneading or mixing by a kneading means such as, or a stirring means such as a super mixer or a planetary mixer. In addition, pre-kneading or pre-mixing may be performed before the kneading or mixing step, if necessary.

Next, an example of how to use the photosensitive resin composition of the present invention will be described. For example, the photosensitive resin composition prepared as described above is coated on a flexible printed wiring board and exposed to an insulating coating (for example, a solder resist film) on the flexible printed wiring board. Can be formed. The method of applying the photosensitive resin composition of the present invention onto the flexible printed wiring board is not particularly limited. For example, the surface of the flexible printed wiring board is treated with an acid to clean the surface, and then the washed surface is used. , Screen printing method, bar coater method, blade coater method, knife coater method, roll coater method, and other known coating methods are used to apply a photosensitive resin composition to a predetermined thickness, for example, a film thickness after curing of 20 to 20 to A coating film is formed by applying a coating to a desired portion so as to have a thickness of 23 μm. After forming the coating film of the photosensitive resin composition, if necessary, pre-drying by heating at a temperature of about 60 to 100 ° C. for about 1 to 30 minutes is performed to make the coating film in a tack-free state. Next, a negative film having a translucent pattern other than the land of the circuit pattern is brought into close contact with the coating film of the photosensitive resin composition, and ultraviolet rays (for example, a wavelength range of 310 to 400 nm) are irradiated from above. Then, the coating film is photocured. Next, the coating film is developed by removing the non-exposed region corresponding to the land with a dilute alkaline solution (developing solution). A spray method, a shower method, or the like is used as the developing method, and examples of the dilute alkaline solution used include a 0.5 to 5% by mass sodium carbonate aqueous solution. Next, by performing post-cure (main curing, thermosetting treatment) at a temperature of about 130 to 170 ° C. for 10 to 80 minutes, the flexible printed wiring board has a photocurable film having a desired coating design formed on the flexible printed wiring board. Printed wiring boards can be manufactured.

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 1-9, Comparative Examples 1-4
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 9 and Comparative Examples 1 to 4 are used. A sex resin composition was prepared. Unless otherwise specified, the blending amount of each component shown in Table 1 below is shown in parts by mass. In addition, the blank part of the compounding amount in Table 1 below means that there is no compounding. The details of each component in Table 1 are as follows.

(A) Carboxylic group-containing photosensitive resin-ZAR-2000, FLR-1122, ZCR-1601H: Solid content (resin content) 65% by mass, diethylene glycol monoethyl ether acetate 35% by mass, Nippon Kayaku Co., Ltd. , ZAR-2000, FLR-1122, ZCR-1601H have a structure obtained by reacting at least a part of the epoxy groups of an epoxy resin with acrylic acid to obtain epoxy acrylate, and reacting the generated hydroxyl groups with polybasic acid. There is a polybasic acid-modified epoxy acrylate.

・ Synthetic resin A
106.1 g of biphenylaralkyl type epoxy resin (NC-3000, epoxy group: 0.383 mol, Nippon Kayaku Co., Ltd.) in a 300 mL 4-port separable flask equipped with a stirrer, thermometer, perfusion tube and nitrogen introduction tube. ), 16.0 g of epoxy acid (carboxylic acid: 0.123 mol, Kishida Chemical Co., Ltd.), 11.6 g of sebacic acid (carboxylic acid: 0.115 mol, Kishida Chemical Co., Ltd.), ethyl diglycol acetate (EDGAC, Sanyo Kasei) 63.6 g was added and stirred at 110 ° C. for 30 minutes in a nitrogen / oxygen mixed gas atmosphere to mix and dissolve. Next, after raising the temperature of the reaction solution to 115 ° C., 0.3 g of p-methoxyphenol (Kishida Chemical Co., Ltd.) and 10.4 g of acrylic acid (carboxylic acid: 0.145 mol, Osaka Organic Chemical Industry Co., Ltd.) ), 0.8 g of triphenylphosphine (TPP) (Kishida Chemical Co., Ltd.) was added. The mixture was stirred at 115 ° C. for 8 hours, and the acid value was measured to confirm that the carboxylic acid was completely eliminated. Next, under an air atmosphere, 23.8 g of hydrogenated trimellitic anhydride (carboxylic acid anhydride: 0.120 mol, HTMAN, Mitsubishi Gas Chemicals Co., Ltd.) and 15.9 g of diethyl diglycol (DEDG) were added to this reaction product. (Nippon Embroidery Co., Ltd.) was added, and the mixture was stirred at 100 ° C. for 2 hours. It was confirmed by FT-IR (Infrared Spectrophotometer) that the acid anhydride had disappeared. As a result, 248.4 g of synthetic resin A having a solid content (resin content) of 68% by mass was obtained. The mass average molecular weight was 9700.

(B) Photopolymerization Initiator NCI-831: ADEKA CORPORATION
(C) Epoxy compound-EPICRON 860: DIC Corporation-NC-3000: Nippon Kayaku Co., Ltd.-YX-4000HK: Mitsubishi Chemical Co., Ltd. (D) Carboxyl-modified silicone oil-X-22-3710, X-22- 162C, X-22-3701E: Shinetsu Chemical Industry Co., Ltd. (E) Reactive diluent, DPCA-120: Nippon Kayaku Co., Ltd., Miramer M-600: Toyo Chemical Co., Ltd., STA: Osaka Organic Chemical Industry Co., Ltd. ( F) Silicone particles MSP-SN08: Nikko Rika Co., Ltd., D50 0.8 μm, polymethylsilsesquioxane

Colorant ・ Lionol Blue FG-7351: Toyo Ink Mfg. Co., Ltd. ・ MA-14: Mitsubishi Chemical Co., Ltd. Flame retardant ・ Exolit OP-935: Clariant Japan Co., Ltd. Additive ・ IXE-100: Toa Synthetic Co., Ltd. ・ Melamine: Nissan Chemical Industry Co., Ltd. DICY-7: Mitsubishi Chemical Co., Ltd. Defoaming agent KS-66: Shin-Etsu Chemical Co., Ltd. Non-reactive diluent EDGAC: Sanyo Kasei Co., Ltd.

Silicone oil (without carboxyl group)
・ KF-96-10CS: Shin-Etsu Chemical Co., Ltd. Matting agent ・ Ace mat OK-212: Evonik Industries

Specimen preparation process Substrate: Polyimide film ("ESPANCX MC12-25-00CEM", Nippon Steel & Sumitomo Metal Chemical Co., Ltd., copper foil thickness 12.5 μm, film thickness 25 μm)
Surface treatment: 5% by mass sulfuric acid treatment Coating method: Screen printing (120 mesh)
DRY film thickness: 20-23 μm
Pre-drying: 80 ° C, 20 minutes Exposure: 100 mJ / cm ² on the coating film, Oak Co., Ltd. "HMW-680GW"
Development: 1 mass% sodium carbonate aqueous solution Temperature 30 ° C, spray pressure 0.2 MPa, development time 60 seconds Post-cure (main curing): 150 ° C, 60 minutes

Evaluation items (1) Gloss (gloss value)
The test piece prepared in the above test piece preparation step was measured with a "gross meter VG2000" manufactured by Nippon Denka Kogyo Co., Ltd. at a measurement angle of 60 ° and evaluated as follows.
〇: less than 30, Δ: 30 or more and less than 50, ×: 50 or more

(2) Dielectric breakdown Using a comb-shaped electrode with a test pattern with a conductor line width of 25 μm and a gap between lines of 25 μm, 50 V is applied in a constant temperature and humidity chamber at 85 ° C and 85% humidity to generate ions. migration tester (IMV Corporation, "MIG-8600B / 128") using a resistance measuring the time until drops below 1.0 × 10 ⁶ Ω, as dielectric breakdown time were evaluated as follows ..
〇: 1000 hours or more, ×: less than 1000 hours

(3) Flexibility (flexibility)
For the test piece prepared in the test piece preparation step, 180 ° bending by goby folding was repeated several times, and the crack generation state in the cured coating film at that time was visually observed and the occurrence of cracks was observed with an optical microscope of × 200. The number of times it was not done was measured. The measurement results were evaluated as follows.
⊚: No cracks even after repeated 15-fold bending ○: No cracks even after repeated bending 14 to 10 times △: No cracks even when bent 9 to 5 times ×: Bending 5 times or less Crack occurrence

(4) Coating property The presence or absence of mesh traces on the coating film after screen printing was evaluated.
〇: No mesh trace, ×: With mesh trace

(5) Tackiness The sticking property of the negative film to the coating film when the negative film was brought into contact with the coating film after pre-drying and exposed was evaluated as follows.
◯: No coating film sticking to the negative film, no negative film sticking mark on the coating film △: Negative film sticking mark remains on the coating film ×: The coating film adheres to the negative film after the negative film is peeled off

The evaluation results are shown in Table 1 below.

As shown in Table 1 above, Examples 1 to 9 containing a carboxyl group-containing photosensitive resin, a photopolymerization initiator, an epoxy compound, a carboxyl group-modified silicone oil, and a reactive diluent are excellent. It was possible to obtain a cured coating film having excellent insulation reliability while having a matting effect by reducing the flexibility and glossiness. Further, the photosensitive resin compositions of Examples 1 to 9 were excellent in coatability and tackiness. In particular, from Examples 1, 2 and 3, when the carboxyl group equivalent of the carboxyl group-modified silicone oil is 1450 g / mol to 2300 g / mol, the glossiness is higher than that in the case where the carboxyl group equivalent is 4000 g / mol. It was further reduced. Further, from Examples 1, 7 and 8, when about 9.3 parts by mass of the carboxyl group-modified silicone oil is contained with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin, about 4.6 parts by mass and about 15.4 parts by mass are contained. Compared with the case where a mass part is contained, the matte effect and tackiness by reducing the glossiness are further improved.

Further, when the silicone particles were further blended from Examples 1 and 9, the matting effect due to the reduction in glossiness was further improved.

On the other hand, in Comparative Example 1 in which silicone particles were blended without blending the carboxyl group-modified silicone oil, and Comparative Example 2 in which silicone oil without a carboxyl group was blended instead of the carboxyl group-modified silicone oil, the glossiness was reduced. No matting effect was obtained. Further, in Comparative Example 3 in which a larger amount of silicone particles than in Comparative Example 1 was blended without blending the carboxyl group-modified silicone oil, a matting effect was obtained by reducing the glossiness, but the flexibility and coatability were improved. I couldn't get it. Further, in Comparative Example 4 in which silicone particles and silica as a matting agent were blended, a matting effect was obtained by reducing the glossiness, but flexibility and insulation reliability were not obtained.

In the present invention, it is possible to obtain a cured product having excellent insulation reliability while having excellent flexibility and matting effect, and also to obtain a photosensitive resin composition having excellent coatability. For example, it has high utility value in the field of flexible printed wiring boards where the hiding power of the insulating coating and the insulating reliability are required.

Claims (8)

Photosensitivity containing (A) carboxyl group-containing photosensitive resin, (B) photopolymerization initiator, (C) epoxy compound, (D) carboxyl group-modified silicone oil, and (E) reactive diluent. Sex resin composition. The photosensitive resin composition according to claim 1, wherein the carboxyl group equivalent of the (D) carboxyl group-modified silicone oil is 500 g / mol or more and 5000 g / mol or less. The photosensitive resin composition according to claim 1 or 2, wherein the carboxyl group equivalent of the (D) carboxyl group-modified silicone oil is 1000 g / mol or more and 3000 g / mol or less. Any one of claims 1 to 3 in which the (D) carboxyl group-modified silicone oil is contained in an amount of 5.0 parts by mass or more and 13 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. The photosensitive resin composition according to any one of claims 1 to 4, further comprising (F) silicone particles. The photosensitive resin composition according to claim 5, wherein the (F) silicone particles have a cumulative volume percentage of 50% by volume and a particle diameter (D50) of 0.50 μm or more and 2.0 μm or less. The cured product of the photosensitive resin composition according to any one of claims 1 to 6. A flexible printed wiring board having the cured product according to claim 7.