TWI658325B - Photosensitive resin composition, dry film, cured product, and printed wiring board - Google Patents

Abstract

An object of the present invention is to provide a photosensitive resin composition which is hard to produce abrasion marks on a cured product, a dry film obtained by coating and drying the composition, a cured product of the composition or the dried film, and a cured product having the cured product. Printed wiring board.

As a solution, the present invention is to provide a photosensitive resin composition characterized by including (A) a carboxyl group-containing resin, (B) a urethane (meth) acrylate having 6 or more functional groups, and (C ) Photopolymerization initiator and (D) titanium oxide. The weight average molecular weight of the urethane (meth) acrylate having 6 or more (B) functional groups is preferably 1,500 to 200,000.

Description

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

The present invention relates to a photosensitive resin composition, a dry film, a cured product, and a printed wiring board. In particular, the present invention relates to a photosensitive resin composition which is hard to produce abrasion marks on the cured product, and the composition is coated and dried. The resulting dry film, the composition or a cured product of the dried film, and a printed wiring board having the cured product.

A photosensitive resin composition is applied to a substrate such as a printed wiring board and photocured, and is widely used as an insulating layer such as solder resist (for example, Patent Document 1). When a photocurable composition is used as an insulating layer in a printed wiring board on which light emitting elements such as light emitting diodes (LEDs) and electroluminescence (EL) are mounted, in order to make efficient use of light, high reflectivity is often used. A white photosensitive resin composition (for example, Patent Document 2).

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2005-311233

[Patent Document 2] Japanese Patent Laid-Open No. 2010-160471

When a printed wiring board or an electronic device is manufactured, the printed wiring board is stacked, or the printed wiring board is in contact with a conveying roller, etc., and an insulating layer such as a solder resist provided on the printed wiring board may come into contact with a metal such as copper. In addition, in the case of a solder resist provided on a windable wiring board, when a component is mounted in an electronic device, it may be surrounded by a metal. If titanium oxide is highly filled in order to obtain a white solder mask having a high reflectance, there is a problem that abrasion marks are generated on the solder mask due to contact with a metal during such manufacturing or practical use.

Herein, an object of the present invention is to provide a photosensitive resin composition which is hard to produce abrasion marks on a cured product, a dry film formed by coating and drying the composition, the composition or a cured product of the dry film, and Hardened printed wiring board.

The present inventors conducted intensive studies in order to solve the above-mentioned problems, and found that the photosensitive resin composition contains a urethane (meth) acrylate having 6 or more functional groups, which can solve the above-mentioned problems, thereby completing the present invention. .

That is, the photosensitive resin composition of the present invention is characterized by including (A) a resin containing a carboxyl group, and (B) ammonia having 6 or more functional groups. Urethane (meth) acrylate, (C) a photopolymerization initiator, and (D) titanium oxide.

In the photosensitive resin composition of the present invention, the weight average molecular weight of the urethane (meth) acrylate having 6 or more functional groups (B) is preferably 1,500 to 200,000.

The photosensitive resin composition of the present invention preferably further contains at least any one of a metal hydroxide and a phosphorus compound.

The dry film of the present invention is characterized in that the photosensitive resin composition is coated on a film and dried.

The cured product of the present invention is obtained by curing the photosensitive resin composition or the dry film.

The printed wiring board of the present invention is characterized by having the aforementioned hardened material.

According to the present invention, it is possible to provide a photosensitive resin composition which is excellent in resolvability and foldability of a cured product, and hardly produces friction marks on the cured product, a dried film obtained by coating the composition, and drying the composition, and the composition. Or hardened matter of the dry film and printed wiring board having the hardened matter.

The photosensitive resin composition of the present invention is characterized by including (A) a carboxyl group-containing resin and (B) a urethane (meth) acrylate having 6 or more functional groups (hereinafter, simply referred to as "(B) Urethane Group) acrylate "), (C) a photopolymerization initiator, and (D) titanium oxide. The friction marks produced by the hardened material are considered to be due to the high hardness of the titanium oxide. Therefore, due to the friction with the metal, the metal scraped by the titanium oxide exposed on the solder resist surface adheres to the solder resist surface. In the present invention, it is considered that by blending a urethane (meth) acrylate having 6 or more functional groups, the hardness of the surface of the hardened product will be increased, and the exposure of titanium oxide due to friction will be reduced. Friction marks are less likely to occur (hereinafter also referred to as "excellent scratch resistance"). In addition, as another means for improving the surface hardness, it is considered that the blending amount of the photopolymerization initiator or the photopolymerizable monomer is increased. However, the hardened material obtained by the photosensitive resin composition of the present invention may be increased by these means. Both the deteriorated resolution and the foldability of the cured product are excellent. In addition, when titanium oxide is filled, the gloss decreases, but the cured product obtained from the photosensitive resin composition of the present invention also has good gloss. Herein, "(meth) acrylate" means the general term of acrylate, methyl acrylate, and mixtures thereof, and other similar expressions in this specification are also the same. Hereinafter, each component is demonstrated in detail.

[(A) Resin containing carboxyl group]

As the (A) carboxyl group-containing resin, a resin containing a well-known carboxyl group can be used. By the presence of a carboxyl group, the resin composition can be made alkali developable. In addition, from the viewpoint of making the photosensitive resin composition of the present invention photocurable or developable, it is preferable to have an ethylenically unsaturated bond in the molecule in addition to the carboxyl group. A carboxyl group-containing resin having a saturated double bond is used as the component (A). As ethylenically unsaturated The double bond is preferably acrylic acid or methacrylic acid or a derivative derived therefrom. (A) A carboxyl group-containing resin can be used individually by 1 type or in combination of 2 or more types.

Specific examples of the carboxyl group-containing resin that can be used in the photosensitive resin composition of the present invention include the following compounds (either an oligomer or a polymer may be used).

(1) Carboxyl-containing resins obtained by copolymerizing unsaturated carboxylic acids such as (meth) acrylic acid with unsaturated group-containing compounds such as styrene, α-methylstyrene, lower alkyl (meth) acrylates, and isobutylene .

(2) Carboxy-containing diethanol compounds such as diisocyanates of aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, and dimethylolpropionic acid, dimethylolbutyric acid And it has polycarbonate polyol, polyether polyol, polyester polyol, polyolefin polyol, propylene polyol, bisphenol A alkylene oxide adduct glycol, phenolic hydroxyl group and alcohol Carboxyl-containing urethane resin formed by addition polymerization of a diol compound such as a hydroxy compound.

(3) Diisocyanate compounds such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, etc., and having polycarbonate polyols, polyether polyols, polyester polyols, Polyurethane-based polyols, propylene-based polyols, bisphenol A-based alkylene oxide adduct glycols, phenolic hydroxyl groups, and alcoholic hydroxyl compounds such as glycol compounds Urethane tree fat.

(4) Diisocyanate and bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisxylenol epoxy resin, bisphenol (Meth) acrylic acid esters of bifunctional epoxy resins such as type epoxy resins or modified anhydrides thereof, photosensitive carboxyl group-containing carbamic acid formed by addition polymerization reaction of carboxyl-containing diethanol compounds and glycol compounds Ethyl resin.

(5) In the resin synthesis of the above (2) or (4), a compound having one hydroxyl group and one or more (meth) acrylfluorenyl groups in a molecule, such as a hydroxyalkyl (meth) acrylate, is added, and Carboxyl-containing urethane resin subjected to terminal (meth) acrylation.

(6) In the resin synthesis of the above (2) or (4), a mole reactant such as isophorone diisocyanate and pentaerythritol triacrylate is added, and the molecule has one isocyanate group and one or more (methyl groups) ) A compound of acrylfluorenyl group and a carboxyl group-containing urethane resin subjected to terminal (meth) acrylation.

(7) A polyfunctional epoxy resin as described below is reacted with (meth) acrylic acid, and phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic acid are added to the hydroxyl groups present on the side chains. A photosensitive carboxyl group-containing resin after a dibasic acid anhydride such as an anhydride. Here, the polyfunctional epoxy resin may be solid or liquid.

(8) The hydroxyl group of the bifunctional epoxy resin is further epoxidized with epichlorohydrin, and the polyfunctional epoxy resin is reacted with (meth) acrylic acid. tree fat. Here, the bifunctional epoxy resin may be solid or liquid.

(9) A polyester resin containing a carboxyl group, in which a polyfunctional propylene oxide resin as described later is reacted with a dicarboxylic acid, and a dibasic acid anhydride is added to the generated primary hydroxyl group.

(10) A reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide is reacted with a monocarboxylic acid containing an unsaturated group, and the obtained reaction is formed into A carboxyl group-containing photosensitive resin obtained by reacting a substance with a polybasic acid anhydride.

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

(12) An epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule and p-hydroxyphenylethanol, etc., and (meth) acrylic acid Monocarboxylic acids containing unsaturated groups are reacted, and the alcoholic hydroxyl groups of the obtained reaction products are reacted with maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid, etc. A carboxyl group-containing photosensitive resin obtained by reaction of a polybasic acid anhydride.

(13) A molecule having epoxy propyl (meth) acrylate, α-methyl epoxy propyl (meth) acrylate, etc. added to the resin of any one of (1) to (12) above A photosensitive carboxyl group-containing resin formed from a compound having one epoxy group and one or more (meth) acrylfluorenyl groups.

As mentioned above, the resin containing carboxyl group is in the skeleton. Since the polymer has a large number of carboxyl groups on its side chain, it can be developed with a dilute aqueous alkali solution.

The acid value of the (A) carboxyl group-containing resin is preferably in the range of 20 to 200 mgKOH / g, and more preferably in the range of 40 to 150 mgKOH / g. When the acid value of the carboxyl group-containing resin is 20 mgKOH / g or more, the adhesion of the coating film is good, and alkali development is also good. On the other hand, when the acid value is 200 mgKOH / g or less, the dissolution of the exposed portion caused by the developing solution is suppressed. If necessary, the lines become thinner. Depending on the situation, the factors can be suppressed regardless of the exposed portion and the unexposed portion. The developer is dissolved and peeled off, and the photoresist pattern is well drawn.

In addition, the weight average molecular weight of the (A) carboxyl group-containing resin varies depending on the resin skeleton, but is preferably in the range of 2,000 to 150,000, and more preferably in the range of 5,000 to 100,000. When the weight-average molecular weight is 2,000 or more, the non-peeling performance is good, and the moisture resistance of the coating film after exposure is good, and it is possible to suppress film reduction during development and to suppress reduction in resolution. On the other hand, when the weight average molecular weight is 150,000 or less, the developability is good and the storage stability is also excellent. The weight average molecular weight can be measured by permeation chromatography.

Among the carboxyl group-containing resins, the polyfunctional epoxy resin used for the synthesis of the resin has a structure selected from a bisphenol A structure, a bisphenol F structure, a bisxylenol structure, a bisphenol novolac structure, a bisxylenol structure, and In the case of a partially-structured polyfunctional epoxy resin or a hydrogenated compound thereof in a group formed by a biphenol aldehyde structure, or a carboxyl group-containing resin having a urethane structure, the resulting cured product has low bending and folding resistance. View Point of view is better.

In addition, among carboxyl group-containing resins having a urethane structure, as a component having an isocyanate group (including a diisocyanate), a carboxyl group-containing urethane resin is obtained by using a diisocyanate group in which an isocyanate group does not directly bond a benzene ring. Since it has less yellow discoloration, is effective for concealment, and has less ultraviolet absorption, it is preferred as an alkali developable composition because it has excellent resolvability.

(A) The compounding amount of the carboxyl group-containing resin is in terms of solid content. In the entire composition, it is preferably 5 to 60% by mass, still more preferably 10 to 60% by mass, and even more preferably 15 to 50% by mass. When it is 5 mass% or more, the coating film strength becomes good. On the other hand, when it is 60% by mass or less, the viscosity of the composition does not become too high, and the coatability and the like are also good.

[(B) Urethane (meth) acrylate]

The photosensitive resin composition of the present invention contains (B) a urethane (meth) acrylate having 6 or more functional groups. The functional group described herein means acrylfluorenyl or methacrylfluorenyl. The number of functional groups is preferably 6 to 15. When it is in the said range, the folding property and resolvability of a coating film can be made compatible, and scratch resistance is more excellent.

(B) The weight average molecular weight of the urethane (meth) acrylate having 6 or more functional groups is preferably 1,500 to 200,000. When it is in the said range, the developability of a hardened part and the developability of an unhardened part can be made to stand, and scratch resistance is more excellent. More preferably, it is 1,500 to 40,000.

As (B) urethane (meth) acrylate, it is possible to Use Art Resin UN-3320HA, UN-3320HABA, UN-3320HB, UN-3320HC, UN-3320HS, UN-904, UN-901T, UN-905, UN-952, Daicel-allnex company made EBECRYL220, 5129, 8301, Daicel-allnex company KRM8200, 8200AE, 8452, Sartomer company CN968, 975, Shin Nakamura Chemical Industry Company U-6LPA, U-10HA, U-10PA, UA-1100H, U-15HA, UA- 53H, UA-33H, etc. (B) A urethane (meth) acrylate can be used individually by 1 type or in combination of 2 or more types.

The blending amount of the (B) urethane (meth) acrylate is preferably 10 to 200 parts by mass relative to 100 parts by mass of the resin having a carboxyl group in (A). In the above range, the contrast between the developability of the hardened portion and the developability of the unhardened portion can be maintained, and the resolution is also excellent. In addition, the gloss is more excellent. More preferably, it is 10 to 150 parts by mass. In addition, the photosensitive resin composition of the present invention contains, in addition to (B) a urethane (meth) acrylate, a compound (photopolymerizable monomer) having one or more ethylenically unsaturated groups in the molecule.

(B) The urethane (meth) acrylate does not contain a carboxyl group.

[(C) Photopolymerization initiator]

The photosensitive resin composition of the present invention contains (C) a photopolymerization initiator. As the (C) photopolymerization initiator, an oxime ester-based photopolymerization initiator having an oxime ester group, an alkylacetone-based photopolymerization initiator, and α-aminoacetophenone-based photopolymerization can be appropriately used. Initiator, fluorenylphosphine oxide-based photopolymerization initiator, One or more photopolymerization initiators in the group formed by the titanocene-based photopolymerization initiator. The oxime ester-based photopolymerization initiator can be completed with a small amount of addition, and can suppress exhaust gas, so it is effective and preferable in terms of PCT resistance or crack resistance.

Examples of the oxime ester-based photopolymerization initiator include CGI-325, IRGACURE-OXE01, IRGACURE-OXE02, ADEKA N-1919, and NCI-831 manufactured by BASF Japan, which are commercially available products. In addition, a photopolymerization initiator having two oxime ester groups in the molecule can be suitably used. The oxime ester-based photopolymerization initiator is particularly preferably a compound having a carbazole structure.

The blending amount of such an oxime ester-based photopolymerization initiator is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the resin having a carboxyl group (A), and more preferably 0.25 to 5 parts by mass. By setting 0.01 to 10 parts by mass, a cured film having excellent photo-hardening properties and resolving properties, improved adhesion and PCT resistance, and excellent chemical resistance such as electroless gold plating resistance can be obtained. In particular, if it is 5 parts by mass or less, it is possible to suppress a decrease in deep hardenability due to intense light absorption on the surface of the coating film.

Examples of commercially available products of the alkyl ethyl ketone-based photopolymerization initiator include α-hydroxyalkyl ethyl ketone types such as IRGACURE-184, DAROCUR-1173, IRGACURE-2959, and IRGACURE-127 manufactured by BASF Japan.

Examples of the α-aminoacetophenone-based photopolymerization initiator include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinylacetone-1,2- Benzyl-2-dimethylamino-1- (4-morpholinylphenyl) -butane-1-one, 2- (dimethylamino)- 2-[(4-Benzyl) methyl] -1- [4- (4-morphino) phenyl] -1-butanone, N, N-dimethylamine acetophenone, and the like. Examples of commercially available products include IRGACURE-907, IRGACURE-369, and IRGACURE-379 manufactured by BASF Japan.

Specific examples of the fluorenylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzylfluorenyldiphenylphosphine oxide and bis (2,4,6-trimethyl Benzamidine) -phenylphosphine oxide, bis (2,6-dimethoxybenzylfluorenyl) -2,4,4-trimethyl-pentylphosphine oxide, and the like. Examples of commercially available products include LUCIRIN TPO manufactured by BASF, and IRGACURE-819 manufactured by BASF Japan.

The blending amount of these α-aminoacetophenone-based photopolymerization initiators and fluorenylphosphine oxide-based photopolymerization initiators is 0.1 to 25 parts by mass relative to 100 parts by mass of the resin containing a carboxyl group (A). It is preferably from 1 to 20 parts by mass. When it is 0.1 to 25 parts by mass, a cured film having excellent photohardenability and resolution, improved adhesion and PCT resistance, and excellent chemical resistance such as electroless gold plating resistance can be obtained. In particular, if the content is 25 parts by mass or less, the effect of reducing exhaust gas is obtained, and further, it is possible to suppress a decrease in deep hardenability due to intense light absorption on the surface of the coating film.

Furthermore, as a photopolymerization initiator, IRGACURE-389 made by BASF Japan can also be used suitably. A more suitable blending amount of IRGACURE-389 is 0.1 to 20 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin, and more preferably 1 to 15 parts by mass.

Furthermore, a titanocene-based photopolymerization initiator such as IRGACURE-784 can also be suitably used. A more suitable titanocene-based photopolymerization initiator The blending amount is 0.01 to 5 parts by mass relative to 100 parts by mass of the carboxyl group-containing resin, and a more suitable blending amount is 0.01 to 3 parts by mass.

By setting these photopolymerization initiators in an appropriate blending amount, it is possible to obtain chemicals that are excellent in photohardening and resolving properties, improve adhesion and PCT resistance, and have electroless gold plating resistance. Hardened material with excellent properties. In addition, when it is an appropriate blending amount, the effect of reducing exhaust gas is obtained, and further, it is possible to suppress a decrease in deep hardenability due to intense light absorption on the surface of the coating film.

The photosensitive resin composition can use a photoinitiator and a sensitizer in addition to the photopolymerization initiator. Examples of the photopolymerization initiator, photoinitiator, and sensitizer that can be suitably used in the photosensitive resin composition include a benzoin compound, an acetophenone compound, an onion compound, a thioxanthone compound, and a ketal. Compounds, diphenyl ketone compounds, tertiary amine compounds, and allicone compounds.

These photopolymerization initiators, photoinitiators and sensitizers can be used alone or in combination of two or more. The total amount of the photopolymerization initiator, photoinitiator, and sensitizer is preferably 35 parts by mass or less with respect to 100 parts by mass of the resin having a carboxyl group (A). If it is 35 parts by mass or less, it is possible to suppress a decrease in deep hardenability due to such light absorption.

[(D) Titanium oxide]

(D) Titanium oxide may be rutile-type titanium oxide or anatase-type titanium oxide, but it is preferable to use rutile-type titanium oxide. Same oxidation Compared with rutile titanium oxide, titanium anatase titanium oxide has a higher whiteness and is often used as a white pigment. However, because anatase titanium oxide has photocatalytic activity, it is sometimes caused especially by LEDs. The irradiated light causes discoloration of the resin in the photosensitive resin composition. On the other hand, although the whiteness of rutile-type titanium oxide is slightly inferior to that of anatase, it has almost no photoactivity, so it can significantly suppress the resin caused by the photoactive light of titanium oxide. It deteriorates (yellow discoloration) and is more stable to heat. Therefore, when used as a white pigment in an insulating layer of a printed wiring board on which LEDs are mounted, high reflectance can be maintained for a long time.

As the rutile titanium oxide, a known one can be used. The rutile-type titanium oxide production method includes two types, a sulfuric acid method and a chlorine atom method, and any one of the production methods can be appropriately used in the present invention. Here, the sulfuric acid method means taking ilmenite ore or titanium slag as a raw material, dissolving this in concentrated sulfuric acid, separating the iron portion as iron sulfate, and then hydrolyzing the solution to obtain a hydroxide precipitate. This method is a method of firing at high temperature to take out a rutile titanium oxide. On the other hand, the chlorine atom method means that synthetic rutile or natural rutile is used as a raw material, and this is reacted with chlorine gas and carbon at a high temperature of about 1000 ° C to synthesize titanium tetrachloride, and then oxidize and remove the rutile. Production method of titanium oxide. Among them, the rutile-type titanium oxide produced by the chlorine atom method is particularly effective in suppressing resin degradation (yellow discoloration) caused by heat, and is more suitably used in the present invention.

Among these titanium oxides, titanium oxide having a surface treated with hydrous alumina or aluminum hydroxide can be used, but it is particularly preferable from the viewpoints of dispersibility, storage stability, and flame retardancy in the composition.

In addition, the cured product formed from the photosensitive resin composition of the present invention preferably has a Y value of 65 or more, and more preferably 70 or more.

The blending amount of (D) titanium oxide is preferably 30 to 300 parts by mass, and more preferably 50 to 250 parts by mass with respect to 100 parts by mass of the resin containing a carboxyl group (A). (D) Titanium oxide can be used individually by 1 type or in combination of 2 or more types. In addition, as long as the effect of the present invention is not impaired, colorants other than titanium oxide may be contained.

(D) Titanium oxide may be a surface treated with silicon dioxide or aluminum oxide.

Titanium oxide surface-treated with silicon dioxide can suppress deterioration of light. Titanium oxide surface-treated with alumina can further increase the reflectivity of the hardened material. Titanium oxide surface-treated with silicon dioxide or alumina can be either anatase or rutile, but it is preferably rutile. In addition, among the rutile titanium oxides, those produced by the chlorine atom method can further suppress deterioration of the resin, which is particularly preferable.

As titanium oxide with silicon dioxide or alumina surface treatment, Tipaque R-930, Tipaque R-630, Tipaque R-680, Tipaque R-670, Tipaque CR-50, Tipaque CR-57, Tipaque CR-97 can be used. , Tipaque CR-60, Tipaque CR-63, Tipaque CR-67, Tipaque CR-58, Tipaque UT771, Tipaque R-820, Tipaque R-830, Tipaque R-550, Tipaque R-780, Tipaque R-780-2 , Tipaque R-850, Tipaque R-855, Tipaque CR-80, Tipaque CR-90, Tipaque CR-90, Tipaque CR-90-2, Tipaque CR-93, Tipaque CR-95, Tipaque CR- 953, Tipaque CR-63, Tipaque CR-85 (manufactured by Ishihara Industries), Taipuya R-100, Taipuya R-101, Taipuya R-102, Taipuya R-103, Taipuya R-104, Taipuya R-105, Taipuya R -108, Taipuya R-900, Taipuya R-902, Taipuya R-960, Taipuya R-706, Taipuya R-931 (manufactured by Du Pont), TITON R-25, TITON R-21, TITON R-32, TITON R-7E, TITON R-5N, TITON R-61N, TITON R-62N, TITON R-42, TITON R-45M, TITON R-44, TITON R-49S, TITON GTR-100, TITON GTR-300, TITON D-918, TITON TCR-29, TITON TCR-52, TITON FTR-700 (manufactured by Sakai Chemical Industry Co., Ltd.), TITANIX JR-300, TITANIX JR-403, TITANIX JR-405, TITANIX JR-600A, TITANIX JR-600E , TITANIX JR-602, TITANIX JR-602S, TITANIX JR-603, TITANIX JR-805 (made by Tayca) and so on.

Examples of the anatase-type titanium oxide include Tipaque A-220 (manufactured by Ishihara Industries Co., Ltd.), TITANIX JA-4 (manufactured by Tayca Corporation), and the like.

The titanium oxide surface-treated with alumina can be further subjected to other surface treatments after being surface-treated with alumina. In particular, after surface treatment with alumina, further surface treatment with zirconia can further increase the reflectance.

Among the above-mentioned titanium oxides, as the titanium oxide treated with alumina surface and then with zirconia surface treatment, there are Tipaque CR-57, Tipaque CR-97, Tipaque CR-67 (made by Ishihara Industry Co., Ltd.), and R-61N , GTR-100, GTR-300 (manufactured by Sakai Chemical Industry Co., Ltd.), TITANIX JR- 603 (manufactured by Tayca).

(Flame retardant)

The photosensitive resin composition of the present invention preferably contains a conventionally known flame retardant for the purpose of improving the flame retardancy of the obtained cured product. From an environmental point of view, a flame retardant containing no halogen is preferred. As the flame retardant, for example, aluminum hydroxide, magnesium hydroxide, hydrotalcite, gibbsite, and the like may be blended with a compound containing phosphorus or an inorganic filler that imparts flame resistance to the resin composition. Among the flame retardants, phosphorus-containing compounds and metal hydroxides are preferred. A flame retardant can be used individually by 1 type or in combination of 2 or more types.

Examples of compounds containing phosphorus include those known as organophosphorus flame retardants. Among such organic phosphorus-based flame retardants, suitable examples include phosphate esters and condensed phosphate esters, (meth) acrylates containing phosphorus elements, phosphorus-containing compounds having phenolic hydroxyl groups, and cyclic phosphorous A nitrogen compound, a phosphorus nitrogen ring oligomer, a phosphonic acid metal salt, and a compound represented by the following general formula (I).

(In the formula, R ⁵ , R ⁶ and R ⁷ each independently represent a substituent other than a halogen atom.)

In the above general formula (I), R ⁵ and R ⁶ are preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁷ is an alkyl group having 1 to 4 carbon atoms which may be substituted by a hydrogen atom or a cyano group. Alkyl, 2,5-dihydroxyphenyl, or 3,5-di-t-butyl-4-hydroxyphenyl is preferred, but is not limited thereto.

Commercial products of the phosphorus-containing compound represented by the general formula (I) include HCA, SANKO-220, M-ESTER, HCA-HQ (all are trade names of Sanko Corporation), and the like.

The (meth) acrylate containing a phosphorus element is preferably a compound having a phosphorus element and a plurality of (meth) acrylfluorenyl groups in the molecule, and specifically, R ⁵ in the general formula (I) is mentioned above. Compounds in which R ⁶ is a hydrogen atom and R ⁷ is a (meth) acrylate derivative. In general, it is possible to perform a Mack addition reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with a well-known and commonly used multifunctional (meth) acrylate monomer. To synthesize.

Examples of the (meth) acrylate monomer include diacrylates of ethylene glycol such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; hexanediol and trimethylol Polyvalent alcohols such as propane, pentaerythritol, dipentaerythritol, and p-hydroxyethyl isocyanate, or polyoxyacrylate adducts, propylene oxide adducts, or caprolactone adducts, etc. ; Polyvalent acrylates such as phenoxy acrylate, bisphenol A diacrylate and phenols such as oxyethane adducts or propylene oxide adducts; and urethanes of the above-mentioned polyols Acrylates, glycerol propylene oxide ether, glycerol triglycidyl ether, trimethylolpropane triepoxide Polyvalent acrylates of epoxypropyl ethers such as propyl ether, triglycidyl isotricyanate, and melamine acrylate, and at least one of methyl acrylates corresponding to the above acrylates Wait.

Phosphorus-containing phosphorus-containing compounds having phenolic hydroxyl groups have high hydrophobicity and heat resistance, and there is no reduction in electrical characteristics caused by hydrolysis, and solder heat resistance is also high. In addition, as a more suitable combination, when an epoxy resin is used in a thermosetting resin, it reacts with an epoxy group and is absorbed by the system. Therefore, it has the advantage that there is no overflow after curing. Among the phosphorus-containing compounds having a phenolic hydroxyl group, preferred examples include those in which R ⁷ is a phenyl group substituted with a hydroxyl group in the general formula (I). Examples of commercially available products include HCA-HQ manufactured by Sanko.

The oligomer or polymer containing a phosphorus compound has less reduction in foldability due to the influence of an alkane chain, and because of its large molecular weight, it can obtain the advantage of no overflow after hardening. As commercially available products, there are M-Ester-HP manufactured by Sanko, and Byron337 containing phosphorus by Toyobo.

As a phosphorus-nitrogen ring oligomer, a phenoxy phosphorus-nitrogen ring compound is effective, although substituted or unsubstituted phenoxy phosphorus-nitrogen ring oligomers or cyclic rings of trimers, tetramers, and pentamers And there are liquid or solid powders, but any of them can be used as appropriate. As commercially available products, there are FP-100, FP-300, and FP-390 manufactured by Fushimi Pharmaceutical Co., Ltd. Among them, phenoxy phosphorus nitrogen ring oligomers substituted with polar groups such as alkyl groups, hydroxyl groups or cyano groups have high solubility in carboxyl group-containing resins, and even when added in large amounts, there will be no adverse conditions such as recrystallization. It is better.

In addition, as another phosphorus-nitrogen ring oligomer, a phosphorus acid-containing dicarboxylic acid represented by the following general formula (II) and an anhydride thereof are obtained by reacting at least one kind with an acrylate compound, and contains 1 in the molecule. More than (meth) acrylate compounds.

Examples of the hydrocarbon group having 1 to 6 carbon atoms represented by R ⁸ and R ⁹ in the general formula (II) include an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, and a ring. Alkyl, phenyl. Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, second butyl, third butyl, isobutyl, pentyl, and isopentyl , Third pentyl, hexyl, etc. Examples of the alkenyl group having 1 to 6 carbon atoms include vinyl, propenyl, 3-butenyl, isobutenyl, 4-pentenyl, 5-hexenyl, etc. . The hydrocarbon group having 1 to 6 carbon atoms may be either branched or substituted.

Examples of the phosphorus-containing dicarboxylic acid or its anhydride include a reaction obtained by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with itaconic acid. Compounds and their anhydrides.

The acrylate compound is preferably an acrylate compound having a functional group that reacts with the carboxyl group or carboxylic anhydride of the dicarboxylic acid or its anhydride. Acrylate residues can be added by related reactions. Such an acrylate compound may be a monofunctional acrylate containing one (meth) acrylate group in the molecule, or a polyfunctional acrylate containing two or more (meth) acrylate groups in the molecule. Examples of the functional group include an epoxy group, a hydroxyl group, and an amine group. Examples of the acrylate compound having an epoxy group include glycidyl (meth) acrylate, 2-methyl-2,3-glycidyl (meth) acrylate, and the like. Examples of the acrylate compound having a hydroxyl group include 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate. Examples of the acrylate compound having an amino group include diethylamine ethyl acrylate. Among the above functional groups, an epoxy group and a hydroxyl group are more preferred.

As the reaction method in which the functional group is added, a conventionally known reaction method can be used.

Examples of the phosphorus-nitrogen ring oligomers include the 1- or 2-functional compounds obtained by reacting the phosphorus-containing dicarboxylic acid of the general formula (II) synthesized with the above-mentioned example and glycidyl methacrylate. Phosphorus-nitrogen ring oligomer, or a difunctional phosphorus-nitrogen ring oligomer obtained by reacting diethanol with a dicarboxylic acid and a hydroxy (meth) acrylate of general formula (II) and diethanol if necessary.

The addition amount of the acrylate compound is not particularly limited with respect to the dicarboxylic acid containing a phosphorus element represented by the general formula (II) or an anhydride thereof, but the phosphorus concentration of the phosphorus-nitrogen ring oligomer is adjusted to 2 to 7% Within the range, it is preferable as the acrylate compound.

By using a phosphorus-containing dicarboxylic acid represented by the general formula (II) or an anhydride thereof, a phosphorus-nitrogen ring oligomer having acrylates at both ends can be easily obtained. By using the terminally acrylated phosphorus-nitrogen ring oligomer obtained in this manner, a photosensitive resin composition can be obtained. The photosensitive resin composition is excellent in flexibility and low flexibility, and does not occur during hot pressing. Spilled flame retardant coating.

The phosphorus-nitrogen ring oligomer is a bifunctional phosphorus element-containing acrylate, and is preferred from the viewpoints of flexibility and low flexibility. When the phosphorus-nitrogen ring oligomer is difunctional, heat resistance becomes good, and reduction in flexibility can also be suppressed.

Moreover, the said phosphorus-nitrogen ring oligomer may be used individually by 1 type, and may use 2 or more types together.

In addition, by using a metal phosphonic acid salt, it is possible to improve the flame retardancy without impairing the flexibility of the cured film. By using such a phosphonic acid metal salt excellent in heat resistance, it is possible to suppress the overflow of the flame retardant under thermal pressure during mounting.

Specific examples of the phosphonic acid constituting the metal phosphonic acid include phosphonic acid, dimethylphosphonic acid, ethylmethylphosphonic acid, diethylphosphonic acid, methyl-n-propylphosphonic acid, and methanediphosphonic acid. (Methylphosphonic acid), benzene-1,4- (dimethylphosphonic acid), benzylphosphonic acid, phenylphosphonic acid, diphenylphosphonic acid, and mixtures thereof.

Examples of the metal component constituting the phosphonate include calcium, magnesium, aluminum, zinc, bismuth, manganese, sodium, and potassium. Preferred are calcium, magnesium, aluminum, and zinc.

As a commercially available product of a phosphonic acid metal salt, Clariant is mentioned. Company-made EXOLIT OP 930, EXOLIT OP 935, etc.

The phosphorus-containing compound may be used alone or in combination of two or more. The compounding amount of the phosphorus-containing compound is 5 to 150 parts by mass, and preferably 10 to 100 parts by mass with respect to 100 parts by mass of the resin having a carboxyl group (A). When it is 150 parts by mass or less, the folding characteristics and the like of the obtained cured film become good.

As the metal hydroxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, strontium hydroxide, or the like that can exhibit flame resistance by thermal decomposition can be used. Among them, aluminum hydroxide and magnesium hydroxide can be particularly suitably used.

The aluminum hydroxide may be an untreated surface, and a surface treatment such as a silane coupling agent having a vinyl group or an epoxy group at its terminal, octadecanoic acid, oleic acid, or a phosphate ester may also be used. As commercially available products of aluminum hydroxide, there are Higilite H-42, H-42M, H-42S, H-42T, H-42ST-V, H-42ST-E, H-42I, manufactured by Showa Denko Corporation. H-43, H-43M, H-43S, B1403, B1403ST, B1403T, etc. made by Japan Light Metal Corporation.

Magnesium hydroxide may be a natural product or a synthetic product, and may also be an untreated surface, and a silane coupling agent having a vinyl group or an epoxy group at its terminal, octadecanoic acid, or oil may also be used. Surface treatments such as acids and phosphates. Examples of commercially available products of magnesium hydroxide include KISUMA 5A, KISUMA 5B, KISUMA 5E, KISUMA 5J, KISUMA 5P, KISUMA 5L, and MagnifinH5, MagnifinH7, and MagnifinH10 manufactured by Albemarle.

The blending amount of the inorganic filler that imparts flame retardancy such as aluminum hydroxide, magnesium hydroxide, etc. is preferably 500 parts by mass or less, and still more preferably 0.1 to 300 parts by mass relative to 100 parts by mass of the (A) carboxyl group-containing resin. Parts, particularly preferably 0.1 to 150 parts by mass. When the blending amount of the filler is 500 parts by mass or less, the viscosity of the photosensitive resin composition is not excessively high, the printability is good, and the cured product is difficult to become brittle.

The average particle diameter (d50) of the inorganic filler imparting flame resistance is preferably 30 μm or less, and even more preferably 15 μm or less. By setting the average particle diameter to 30 μm or less, it is possible to make friction marks more difficult to occur. The lower limit value of the average particle diameter (d50) is, for example, 0.05 μm or more. The average particle diameter (d50) can be measured by a laser diffraction / scattering method.

(Thermosetting component)

The photosensitive resin composition of the present invention is preferably blended with a thermosetting component. By adding a thermosetting component, heat resistance can be expected to improve. As the thermosetting component, any one of known ones can be used. For example, amine resins such as melamine resins, benzoguanamine resins, melamine derivatives, benzoguanamine derivatives, isocyanate compounds, block isocyanate compounds, cyclic carbonate compounds, polyfunctional epoxy compounds, and polyfunctional epoxy resins can be used. Conventional thermosetting components such as propane compounds, epoxy sulfide resins, bismaleimide, and carbodiimide resins. Particularly preferred is a thermosetting component having a plurality of cyclic ether groups or cyclic ethyl sulfide groups (hereinafter abbreviated as cyclic (thio) ether groups) in the molecule. A thermosetting component can be used individually by 1 type or in combination of 2 or more types.

The heat-hardening component having a plurality of cyclic (thio) ether groups in the above-mentioned molecule is a compound having a plurality of cyclic (thio) ether groups having 3, 4 or 5 members in the molecule. Epoxy compounds, that is, polyfunctional epoxy compounds, compounds having a plurality of propylene oxide groups in the molecule, that is, polyfunctional propylene oxide compounds, compounds having a plurality of ethyl sulfide groups in the molecule, that is, Epoxy sulfide resin, etc.

Examples of the polyfunctional epoxy compound include epoxidized vegetable oil; bisphenol A epoxy resin; hydroquinone epoxy resin; bisphenol epoxy resin; ethyl sulfide epoxy resin; brominated epoxy resin; Phenolic epoxy resin; bisphenol novolac epoxy resin; bisphenol F epoxy resin; hydrogenated bisphenol A epoxy resin; epoxypropylamine epoxy resin; hydantoin epoxy resin; Alicyclic epoxy resins; trihydroxyphenylmethane epoxy resins; bisxylenol or bisphenol epoxy resins or mixtures thereof; bisphenol S epoxy resins; bisphenol A phenolic epoxy resins Resin; Tetraethylbenzene type epoxy resin; Compound cyclic epoxy resin; Diglycidyl phthalate resin; Tetraglycidyl xylenyl ethane resin; Naphthyl-containing epoxy resin; Epoxy resin with sesquicyclopentadiene skeleton; epoxy epoxy methyl acrylate copolymer epoxy resin; cyclohexyl maleimide and epoxy epoxy methyl acrylate copolymer epoxy; epoxy Modified polybutadiene rubber derivatives; CTBN modified epoxy resin, etc., but not limited to these. These epoxy resins can be used individually by 1 type or in combination of 2 or more types. Among these, especially phenolic epoxy resin, bisphenol epoxy resin, bisxylenol epoxy resin, bisphenol epoxy resin, bisphenol novolac epoxy resin, naphthalene epoxy resin or These mixtures are preferred.

Examples of the polyfunctional propylene oxide compound include bis [(3-methyl-3-glycidyloxy) methyl] ether and bis [(3-ethyl-3-glycidylmethoxy). Methyl] ether, 1,4-bis [(3-methyl-3-glycidyloxy) methyl] benzene, 1,4-bis [(3-ethyl-3-glycidyloxy) (Methyl) methyl] benzene, (3-methyl-3-propylene oxide) methacrylate, (3-ethyl-3-propylene oxide) methacrylate, (3-methyl-3-cyclo Oxypropane) methyl methacrylate, (3-ethyl-3-epoxypropane) methyl methacrylate or polyfunctional propylene oxides such as oligomers or copolymers, etc. Ethers of propylene oxide and phenolic resins, poly (p-hydroxystyrene), cation-based bisphenols, phenolic cyclic polymers, aromatic cups, or resins with hydroxyl groups such as hemisiloxane物 等。 And so on. A copolymer of an unsaturated monomer having a propylene oxide ring and an alkyl (meth) acrylate is also mentioned.

Examples of the compound having a plurality of cyclic ethyl sulfide groups in the molecule include a bisphenol A type epoxy sulfide resin. In addition, an epoxy sulfide resin or the like in which an oxygen atom of an epoxy group of a phenolic epoxy resin is replaced with a sulfur atom by the same synthetic method can also be used. The blending amount of the thermosetting component having a plurality of cyclic (thio) ether groups in such a molecule is preferably 0.6 to 2.5 equivalents with respect to 1 equivalent of the carboxyl group of the resin containing the carboxyl group (A). When the blending amount is 0.6 equivalent or more, it is difficult for the carboxyl group to remain on the cured product, and heat resistance, alkali resistance, electrical insulation, and the like are good. On the other hand, when it is 2.5 equivalents or less, it is difficult for a low-molecular-weight cyclic (thio) ether group to remain on the dried coating film, and the strength and the like of the coating film are good. It is more preferably 0.8 to 2.0 equivalents.

Examples of amine-based resins such as melamine derivatives and benzoguanamine derivatives include methylol melamine compounds and methylol benzoguanamine compounds. Compounds, methylol urea compounds, and methylol urea compounds.

As the isocyanate compound, a polyisocyanate compound can be blended. Examples of the polyisocyanate compound include 4,4'-diphenylmethane diisocyanate, toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, naphthalene-1,5-diisocyanate, o -Aromatic polyisocyanates such as xylylene diisocyanate, m-xylylene diisocyanate, and 2,4-methylenephenyl dimer; tetramethylene diisocyanate, hexamethylene diisocyanate, methylene Aliphatic polyisocyanates such as diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methene bis (cyclohexyl isocyanate), and isophorone diisocyanate; alicyclic polyisocyanates such as dicycloheptane triisocyanate ; And adducts, biuret bodies, and isocyanurate bodies of the isocyanate compounds previously cited.

As the block isocyanate compound, an additive reaction product of an isocyanate compound and an isocyanate blocking agent can be used. Examples of the isocyanate compound capable of reacting with the isocyanate blocking agent include the aforementioned polyisocyanate compounds. Examples of isocyanate blocking agents include phenol-based blocking agents; lactam-based blocking agents; active methylene-based blocking agents; alcohol-based blocking agents; oxime-based blocking agents; thiol-based blocking agents; Imidamine-based block agents; imidamine-based block agents; amine-based block agents; imidazole-based block agents; imine-based block agents and the like.

The blending amount of such a polyisocyanate compound or a block isocyanate compound is preferably 1 to 100 parts by mass with respect to 100 parts by mass of the resin having a carboxyl group (A). When the blending amount is 1 part by mass or more, sufficient toughness of the coating film can be obtained. On the other hand, when it is 100 mass or less, save Good stability. It is more preferably 2 to 70 parts by mass.

(Other photopolymerizable monomers)

The photosensitive resin composition of the present invention contains (B) urethane (meth) acrylate and phosphorus element-containing (meth) acrylate which can be used as a flame retardant, and can also contain other photopolymerizable properties. monomer. The photopolymerizable monomer is a compound having one or more ethylenically unsaturated groups in the molecule, and is used to inactivate the resin containing the carboxyl group (A) or to assist insolubilization in an alkaline aqueous solution after photocuring by activation energy ray irradiation. By.

As the compound used as the other photopolymerizable monomer, any one of known ones can be used. For example, conventionally known polyester (meth) acrylates, polyether (meth) acrylates, carbonate (meth) acrylates, and epoxy (meth) acrylates can be used. Specific examples include 2 -Hydroxyalkyl acrylates such as hydroxyethyl acrylate and 2-hydroxypropyl acrylate; ethylene glycol diacrylates of ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, propylene glycol, etc. Class; N, N-dimethylacrylamide, N-methylmethacrylamide, N, N-dimethylaminopropylacrylamide, etc .; N, N-dimethylamine Amino alkyl acrylates such as ethyl acrylate, N, N-dimethylaminopropyl acrylate, etc .; hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, p-hydroxyethyl isocyanate, etc. Polyvalent alcohols or polyvalent acrylates such as oxyethane adducts, propylene oxide adducts or ε-caprolactone adducts; phenoxy acrylates, bisphenol A diacrylates, and The valence of these phenolic oxyethane adducts or propylene oxide adducts Acrylates; glycerol dipropylene oxide, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isotricyanate, etc. Polyvalent acrylates; not limited to the above, there are also acrylates in which polyhydric alcohols such as polyether polyols, polycarbonate diols, hydroxyl-terminated polybutadiene, and polyester polyols are directly acrylated And methyl acrylates and the like corresponding to melamine acrylate and / or the above acrylate. Other photopolymerizable monomers can be used individually by 1 type or in combination of 2 or more types.

The total amount of the photopolymerizable monomer containing the (B) urethane (meth) acrylate and the phosphorus-containing (meth) acrylate which can be used as a flame retardant is contained in the (A) containing a carboxyl group The resin is 100 parts by mass, preferably 10 to 250 parts by mass, and still more preferably 10 to 200 parts by mass. When it is 10 parts by mass or more, the photocurability is good, and the pattern is easily formed by alkali development after irradiation with active energy rays. On the other hand, when it is 250 parts by mass or less, the solubility in an alkaline aqueous solution is good, and a decrease in resolution can be suppressed.

(Antioxidants)

After a large number of polymer materials begin to be oxidized once, continuous oxidative deterioration will continue to occur, and the function of the polymer material will be reduced. Therefore, in order to prevent oxidation of the photosensitive resin composition of the present invention, it is possible to add (1) Antioxidants such as radical supplements that invalidate the generated radicals and / or (2) decomposition of the generated peroxides into harmless substances, and do not generate new radicals such as peroxide decomposition agents.

Specific examples of the antioxidant having a function of a free radical supplement include hydroquinone, 4-tert-butylcatechol, 2-t-butylhydroquinone, hydroquinone monomethyl ether, 2, 6-di-t-butyl-p-cresol, 2,2-methenebis- (4-methyl-6-t-butylphenol), 1,1,3-ginseng (2-methyl- 4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-para (3,5-di-t-butyl-4-hydroxybenzyl) ) Benzene, 1,3,5-ginseng (3 ', 5'di-t-butyl-4-hydroxybenzyl) -S-triazabenzene-2,4,6- (1H, 3H, 5H) Phenols such as triones, quinones such as methylquinone, benzoquinone, bis (2,2,6,6-tetramethyl-4-piperidinyl) -sebacate, thiodiphenylamine, etc. Amine compounds and the like.

Free radical supplements can also be commercially available, such as ADKSTAB AO-30, ADKSTAB AO-330, ADKSTAB AO-20, ADKSTAB LA-77, ADKSTAB LA-57, ADKSTAB LA-67, ADKSTAB LA-68, ADKSTAB LA-87 (above, manufactured by ADEKA Corporation, trade name), IRGANOX1010, IRGANOX1035, IRGANOX1076, IRGANOX1135, TINUVIN 111FDL, TINUVIN 123, TINUVIN 144, TINUVIN 152, TINUVIN 292, TINUVIN 5100 (above, manufactured by BASF Japan, trade name) Wait. Specific examples of the antioxidant having a function of a peroxide decomposer include phosphorus-based compounds such as triphenylphosphite, pentaerythritol tetralaurylthiopropionate, and dilaurylthiodipropionic acid. Sulfur compounds such as esters, distearyl 3,3'-thiodipropionate and the like.

The peroxide decomposer may also be commercially available. For example, ADKSTAB TPP (made by ADEKA Corporation, trade name), Mark AO-412S (made by ADEKA Corporation, trade name), SUMILIZER TPS (Sumitomo Chemical) Company system, trade name).

These antioxidants can be used alone or in combination of two or more.

(Organic solvents)

The photosensitive resin composition of the present invention can be used for (A) the synthesis of a carboxyl group-containing resin or the preparation of a composition, or an organic solvent for adjusting the viscosity of a substrate or a carrier film. Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. More specifically, there are ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetra toluene; cyperidine, methyl cyperidine, butyl cyperidine, carbitol, Glycol ethers such as methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; ethyl acetate Ester, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate and the like; ethanol, propanol, ethylene diacetate Alcohols such as alcohols and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum-based solvents such as petroleum ether, petroleum brain, hydrogenated petroleum brain, and solvent petroleum brain. Such an organic solvent can be used individually by 1 type or in combination of 2 or more types.

(Other optional ingredients)

The photosensitive resin composition of the present invention may further contain a whitening additive that reduces the b ^* value in the L ^* a ^* b ^* color system of the composition by heating. Here, the whitening additive means a substance capable of increasing the whiteness of the hardened material of the composition so that it does not appear discolored.

Here, in the specification of the present case, the decrease in the b ^* value of the hardened material of the composition by heating means that when the hardened material of the composition is first heated, the b ^* value decreases, and the second and subsequent heatings are not included. In addition, the heating temperature at this time means the temperature when the composition is substantially mounted with solder, and is specifically 200 ° C or higher, for example, 220 to 370 ° C. The general solder remelting step is performed only once at about 260 ° C. In the case of an additive for whitening, heating at a temperature of about 150 ° C of the composition's curing temperature does not cause a decrease in b ^* value.

As the whitening additive, those having a benzoxazole-based skeleton can be suitably used. Among them, one or more of them have the following formula (I).

(In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 12 carbon atoms which may have a straight chain or a branch). In particular, R ¹ and R ² are each independently an alkyl group having 4 to 8 carbon atoms, and more preferably butyl or octyl. Specifically, the following formula (I-1) can be suitably used. ) ~ (I-3)

(4,4 '-[5-t-butyl-2-benzoxazolyl-4'-(5-t-octyl-2-benzoxazolyl)] stilbene)

(4,4'-bis- [5-t-octyl-2-benzoxazolyl] stilbene)

(4,4'-bis- [5-t-butyl-2-benzoxazolyl] stilbene)

Any one of the compounds shown, or two or more, especially a mixture of three. In addition, as a whitening additive, a decomposition temperature of 400 ° C. or higher is suitable. Here, the reason for setting the decomposition temperature of the whitening additive at 400 ° C or higher is to prevent the temperature of the additive from being caused by heat load during the remelting step. break down. The upper limit of the decomposition temperature is not particularly limited, but there are, for example, 400 ° C to 600 ° C.

The blending amount of the whitening additive is preferably 0.01 to 60 parts by mass with respect to 100 parts by mass of the resin containing a carboxyl group (A), and more preferably 0.1 to 40 parts by mass.

In addition, the photosensitive resin composition of the present invention may include a photo-excitable inorganic filler that has been subjected to a surface treatment. Applying a photo-excitation inorganic filler to a surface treatment means applying an inorganic component to the photo-excitation inorganic filler Or surface treatment of acidic liquids. By using a photo-excitable inorganic filler that has been subjected to a surface treatment, and further satisfying conditions related to the pH value described later, a high reflectance can be achieved in the cured coating film. The reason why the surface-treated inorganic filler is used as the photo-excitation inorganic filler is that by applying the surface treatment, the surface of the photo-excitation inorganic filler will form an insoluble or hardly soluble reaction product, and the water resistance of the surface will be greatly improved. The effect of ground lifting is to maintain high reflectance for a long period of time even in the presence of water.

Examples of the photo-excitable inorganic filler include strontium aluminate, zinc sulfide, and the like. In particular, strontium aluminate can be suitably used. These photo-excitable inorganic fillers may be used alone or in combination of two or more. In addition, examples of the inorganic component used in the surface treatment include silicon dioxide (glass), alumina, and zirconia. As a method of surface treatment using an inorganic component, a well-known method can be used, and it does not specifically limit.

As the acidic liquid, a member selected from the group consisting of nitric acid, hydrochloric acid, carbonic acid, sulfuric acid, sulfurous acid, silicic acid, boric acid, phosphoric acid, phosphorous acid, polyphosphoric acid, first sodium phosphate, sodium hexametaphosphate, acetic acid, butyric acid, and propionic acid can be used. , Caprylic acid, lauric acid, octadecanoic acid, acrylic acid, methacrylic acid, oxalic acid, succinic acid, citric acid, malic acid, tartaric acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, salicylic acid , Benzoic acid, gallic acid, phenol, naphthoic acid, toluenesulfonic acid, benzenesulfonic acid, metaphosphoric acid, taurine, ascorbic acid, silanolic acid, phosphonic acid, crotonic acid, maleic acid, lactic acid, or the like Acid salts such as potassium salts, sodium salts, ammonium salts, and acid anhydride compounds among acid-generating compounds, among which phosphoric acids such as phosphoric acid, phosphorous acid, polyphosphoric acid, and first sodium phosphate and the like are used. Salt structure The resulting phosphoric acid-based compound and sulfuric acid are preferred, and the phosphoric acid-based compound is particularly preferred. The inorganic component and the acidic liquid can be used either alone or in combination of two or more.

Here, the surface treatment of the acidic liquid can use the above-mentioned acidic liquid, and can be performed under the condition of a pH value of 3 or less. For example, a method of immersing a photo-excitable inorganic filler in an aqueous solution containing an acidic liquid can be used. A method of spraying an inorganic filler with an aqueous solution containing an acidic liquid, and a method of contacting the surface of the photo-excitable inorganic filler with the acidic liquid in a high-humidity environment. Among these methods, a method of immersing a photo-excitable inorganic filler in an aqueous solution containing an acidic liquid is suitable from the viewpoint of simple operation and efficient reaction.

Specifically, first, water of about 1 to 1000 mass times, preferably about 2 to 100 mass times, and still more preferably about 3 to 10 mass times of the photoactive inorganic filler is prepared, and the above-mentioned acidic liquid is prepared. It is dissolved so as to have a concentration of about 0.01 to 30% by mass, preferably about 0.5 to 10% by mass. At this time, for the purpose of adjusting the dissolving energy of the acidic liquid, a part of the above water can be replaced with methanol, ethanol, acetone, dioxane, dimethylformamide (DMF), dimethylformamide (DMSO), etc. A water-soluble organic solvent. In this case, the amount of the organic solvent used is not particularly limited, as long as it does not hinder the reaction between the metal oxide of the photo-excitable inorganic filler and the acidic liquid, but it is usually set at a lower capacity than the water used. the amount. In addition, a surfactant may be added to this aqueous solution in order to improve the dispersibility of the photo-excitable inorganic filler. The type and amount of the surfactant can be appropriately determined according to the type and amount of the photo-excitable inorganic filler used. Adjustment.

Next, a photo-excitable inorganic filler is added to an aqueous solution containing an acidic liquid, and uniformly dispersed by stirring, so that the acidic liquid and the metal oxide of the photo-excitable inorganic filler react. The processing temperature at this time is not particularly limited, but usually the liquid temperature can be set to about 20 ° C or higher, preferably 50 ° C to a boiling point temperature range, and the processing time can be set to 0.5 to 120 minutes, preferably 10 ~ 60 minutes.

After the surface treatment of the acidic liquid, at least one basic compound selected from the group consisting of an alkali or a base-generating compound can be used for the alkali treatment. Alkali treatment is carried out at a pH of 4-9, and more suitably at a pH of 4-7. By applying an alkali treatment, the water-resistant inorganic filler obtained by the surface treatment of the above-mentioned acidic liquid has improved water resistance and durability, and can maintain its water resistance even when used at a high temperature for a long period of time. This is considered to be because the reaction product formed on the surface of the photo-excitable inorganic filler is denatured and strengthened more by alkali treatment. Examples of the alkali used in the alkali treatment include sodium hydroxide, lithium hydroxide, calcium hydroxide, potassium hydroxide, strontium hydroxide, and ammonia. However, sodium hydroxide is more suitably used. In addition, as the base-generating compound, a second sodium phosphate, a third sodium phosphate, sodium hexametaphosphate, sodium acetate, strontium acid, and the like are used, but a third sodium phosphate is more suitably used. Further, organic basic compounds such as monoethanolamine, triethanolamine, guanidine, stearylamine, and pyridine can be used.

The means for alkali treatment is not particularly limited, and can be performed, for example, as follows. That is, after the treatment of the acidic liquid, the supernatant can be removed, and an appropriate amount of water can be newly added. Next, stir with a blender, etc. Slowly add the above-mentioned basic compound while stirring, and adjust the pH to 4-9. The processing temperature at this time is not particularly limited, but the liquid temperature is usually set to about 20 ° C or higher, and a temperature range of 50 ° C to a full boiling point is more suitable. The processing time is usually set at 0.5 to 120 minutes, and more suitably 10 to 60 minutes.

After the alkali treatment, the supernatant liquid is removed, and after filtering and washing with water, it is sufficiently dried to obtain the intended photo-excitable inorganic filler for surface treatment. The drying conditions at this time are not particularly limited, but it is usually sufficient to dry at a temperature of 20 ° C or higher for 2 hours or more. The surface-treated photoexcitation inorganic filler can be sieved to obtain a powdery state as necessary. The surface-excited photo-excited inorganic filler thus obtained has a solubility of less than 1 g with respect to 100 g of water at 40 ° C. and has heat resistance, so it can maintain very good water resistance for a long time.

In addition, as a photo-excitation inorganic filler to be subjected to a surface treatment, 10 g of the photo-excitation inorganic filler was added to 50 g of acetone, and once the insoluble component was taken out, after that, the taken-out primary insoluble component was added to 50 g of chloroform, and the secondary insoluble was taken out. Then, the extracted secondary insoluble component is further added to 10 g of pure water, and the pH value of the liquid obtained after stirring at 30 ° C for 1 week is 6-12, which is preferable in terms of obtaining high reflectance.

The compounding quantity of a photoexcitation inorganic filler is 0.1-500 mass parts with respect to 100 mass parts of (A) carboxy resins, for example.

In the photosensitive resin composition of the present invention, a thermal curing catalyst, a urethane-based catalyst, and an epoxy resin can be further blended as necessary. Hardener thermoplastic resin, block copolymer, filler, adhesive polymer, synthetic rubber, adhesion promoter, antioxidant, ultraviolet absorber, thermal polymerization inhibitor and other components. These can be used in the field of electronic materials. In addition, the photosensitive resin composition of the present invention can be blended with well-known and commonly used thickeners such as silica, hydrotalcite, organic bentonite, kaolinite, etc., silica-based, fluorine-based, and polymer-based. Defoaming agents and / or leveling agents, silane coupling agents such as imidazole-based, thiazole-based, triazole-based, and rust-removing agents are conventional and commonly used additives.

The photosensitive resin composition of the present invention is useful for forming a protective layer of a circuit pattern of a printed wiring board, and is particularly useful for forming a permanent insulating film. Among them, it is useful as a material required for forming an outermost portion including a solder resist or a self-adhesive film. In particular, there are materials for solder masks or adhesive films for flexible printed wiring boards having light emitting elements such as LEDs mounted thereon. The flexible printed wiring board provided with the solder resist formed by the photosensitive resin composition of this invention can be used suitably for a backboard of LED lighting etc. In addition, the photosensitive resin composition of the present invention can be used not only for flexible printed wiring boards, but also for rigid printed wiring boards. The photosensitive resin composition of the present invention can also be used for forming a solder dam.

The photosensitive resin composition of the present invention can be in the form of a dry film including a carrier film (support) and a layer composed of the photosensitive resin composition formed on the carrier film. When the film is dried, the photosensitive resin composition of the present invention can be diluted with the above-mentioned organic solvent, adjusted to an appropriate viscosity, and applied by a spot coater, a sheet coater, a blade coater, a rod coater, or an extruder. Pressure coater, reverse coater, transfer roll coater, gravure A coater, spray coater, etc. are coated on the carrier film with a uniform thickness, and usually dried at a temperature of 50 to 130 ° C for 1 to 30 minutes to obtain a film. There is no particular limitation on the coating film thickness. Generally, the film thickness after drying is appropriately selected from the range of 1 to 150 μm, preferably 10 to 60 μm.

As the carrier film, there are polyester films using polyethylene film, polyethylene glycol terephthalate, etc., polyimide film, polyimide film, polypropylene film, polystyrene film, etc. Plastic film is preferred. There is no particular limitation on the thickness of the carrier film, but in general, it is appropriately selected in the range of 10 to 150 μm.

After forming the photosensitive resin composition of the present invention on a carrier film, it is preferable to laminate a peelable cover film on the surface of the film for the purpose of preventing dust from adhering to the surface of the film. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used. When peeling the cover film, the adhesion force between the film and the cover film is greater than that of the film and the carrier film Then the person with the smaller force can do it.

The photosensitive resin composition of the present invention is adjusted, for example, with the above-mentioned organic solvent to a viscosity suitable for the coating method, and the substrate is subjected to a dip coating method, a flow coating method, a roll coating method, a rod coating method, or a screen printing method. And a curtain coating method, and the organic solvent contained in the composition is evaporated to dryness (temporary drying) at a temperature of about 60 to 100 ° C., thereby forming a coating film that does not peel off. In addition, in order to apply the above composition to a carrier film, dry it, and roll it back as a thin film, the substrate is pasted with a laminator or the like and the photosensitive resin composition layer is brought into contact with the substrate. ,borrow By peeling the carrier film, a resin insulating layer can be formed.

Examples of the substrate include a printed wiring board or a flexible printed wiring board in which a circuit is formed in advance, and examples thereof include the use of phenolic paper, epoxy paper, glass cloth epoxy, glass polyurethane, and glass. Cloth / non-woven epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, using fluorine. Polyethylene. Polyphenylene oxide, polyoxyxylene. All grades (FR-4, etc.) of copper-clad laminates such as cyanate ester copper-clad laminates for high-frequency circuit circuits, other polyurethane films, PET films, glass substrates, ceramic substrates, wafers Wait.

Volatile drying after coating the photosensitive resin composition of the present invention can be performed using a hot-air circulation type drying oven, IR furnace, heating plate, convection oven, etc. (using a heat source with air heating method including steam to make hot air in the dryer The method of direct flow contact and the method in which the nozzle is blown toward the support) are performed.

When the photosensitive resin composition of the present invention contains a thermosetting component, the carboxyl group and the thermosetting component in the resin containing the carboxyl group (A) can be thermally cured by heating to a temperature of, for example, about 140 to 180 ° C. The reaction forms a cured coating film excellent in various properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical characteristics.

By exposing the coating film obtained by applying the photosensitive resin composition of the present invention and volatilizing a dry solvent (irradiation with active energy rays), the exposed portion (the portion irradiated with active energy rays) is hardened. And, by contact (or non-contact), by forming a mask of the pattern, and selectively exposing by active energy rays or direct patterning by a laser direct exposure machine After the exposure, the unexposed portion is developed with a dilute alkali aqueous solution (for example, a 0.3 to 3% by mass sodium carbonate aqueous solution) to form a photoresist pattern.

As the exposure machine used for the activation energy ray irradiation, any device that is equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short-arc lamp, and the like, and irradiates ultraviolet rays in the range of 350 to 450 nm, It is also possible to further use a direct drawing device (for example, a laser direct imaging device that draws an image with a direct laser from CAD data from a computer). As the laser light source of the direct scan machine, as long as it uses laser light with a maximum wavelength in the range of 350 to 410 nm, it can be a gas laser or a solid laser. The exposure amount used for image formation varies depending on the film thickness and the like, but can generally be set in the range of 10 to 100 mJ / cm ² , preferably 20 to 800 mJ / cm ² .

As the developing method, a dipping method, a water spray method, a spray method, a brush method, or the like can be used. As the developing solution, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, Aqueous alkali solution of ammonia, amines, etc.

[Example]

Examples and comparative examples are described below to specifically describe the present invention, but the present invention is not limited to the following examples. In the following, "parts" and "%" mean quality standards as long as there are no special exceptions.

(Synthesis of carboxyl-containing resin A-1)

In a reaction vessel equipped with a stirring device, a thermometer, and a condenser, a polycarbonate diol (manufactured by Asahi-Kasei, T5650J, derived from 1,5-pentanediol and 1,6-hexanediol) was placed. Number average molecular weight 800) 2400 g (3 moles), 603 g (4.5 moles) of dimethylolpropionic acid, and 238 g (2.6 moles) of 2-hydroxyethyl acrylate as a monohydroxy compound. Next, 1887 g (8.5 moles) of isophorone diisocyanate as a polyisocyanate was placed, and heated to 60 ° C while stirring. After stopping, heating was resumed when the temperature in the reaction vessel began to decrease, and the stirring was continued at 80 ° C. After confirming that the absorption spectrum (2280 cm ^-1 ) of the isocyanate group in the infrared absorption spectrum disappeared, the reaction stopped. Carbitol acetate was added to make the solid content 70% by mass. The acid value of the solid content of the obtained carboxyl group-containing resin was 50 mgKOH / g. Hereinafter, the obtained varnish is referred to as a carboxyl group-containing resin solution A-1.

(Preparation of photosensitive resin composition)

The ingredients shown in Table 1 below were blended in the proportions (parts by mass) shown in the table, pre-mixed with a blender, and kneaded with three roller mills to prepare a photosensitive resin composition. The dispersion of each of the photosensitive resin compositions obtained here was evaluated by a particle size measurement of a Grind Meter manufactured by Erichsen, and was 15 μm or less.

* 1: ZFR-1401H (manufactured by Nippon Kayaku Co., Ltd .; solid content 65%)

* 2: UN-3320HA (manufactured by Genjo Industrial Co., Ltd .; 6-functional urethane acrylate)

* 3: UN-904 (manufactured by Gensang Kogyo; 10-functional urethane propylene Enoate)

* 4: UN-3320HSBA (manufactured by Gensang Kogyo; 15-functional urethane acrylate)

* 5: UN-952 (manufactured by Genjo Industrial Co., Ltd .; 10-functional urethane acrylate)

* 6: UN-905 (manufactured by Gensang Kogyo; 15-functional urethane acrylate)

* 7: EBECRYL8405 (manufactured by Daicel-Allnex Corporation; 4-functional urethane acrylate)

* 8: Larmer LR8863 (manufactured by BASF Japan; polyether modified acrylate oligomer)

* 9: LUCIRIN TPO (manufactured by BASF Japan; fluorenylphosphine oxide-based photopolymerization initiator)

* 10: IRGACURE-OXE-02 (manufactured by BASF Japan; oxime ester photopolymerization initiator)

* 11: Tipaque CR-97 (manufactured by Ishihara Industries; rutile titanium oxide)

* 12: Phthalocyanine blue

* 13: HFA-6065E (manufactured by Showa Denko Corporation)

* 14: Exolit OP935 (manufactured by Clariant) (average particle size: 2 to 3 μm)

* 15: Higilite H-42M (manufactured by Showa Denko Corporation) (average particle size: 1 μm)

* 16: NC-3000H (manufactured by Nippon Kayaku Co., Ltd.)

* 17: YX-4000 (manufactured by Mitsubishi Chemical Corporation)

* 18: KS-66 (by Shin-Etsu Chemical Industry Co., Ltd.)

* 19: Disperbyk-111 (by BYK. Japan)

* 20: crushed melamine

* 21: Aerosil # 974 (manufactured by EPOCH)

* 22: DOWANOL DPM (manufactured by Dow Chemical)

<Molecular weight measurement of urethane acrylate>

The weight average molecular weight of urethane acrylate is calculated | required by GPC method (permeation chromatography) by standard polystyrene conversion. The measurement conditions are shown below.

Installation: Waters 2695

Water column: Waters HPSgel HR MB-L (6.0mm × 15cm) 2 And 2 Waters HPSgel HR 1.0 (6.0mm × 15cm)

Sample dilution method: 0.5% by mass of tetrahydrofuran

Solvent: Tetrahydrofuran

Performance evaluation:

<Scratch resistance>

The composition of each Example and Comparative Example was screen-coated on a 1.6 mm copper solid FR-4 substrate so as to have a dry film thickness of 20 μm, dried at 80 ° C. for 30 minutes, and then cooled to room temperature. After that, the exposure device was opened using a contact equipped with an ultra-high pressure mercury lamp (short-arc lamp 5KW), and full exposure was performed at the most appropriate exposure amount. A 1% by mass Na ₂ CO ₃ aqueous solution at 30 ° C. was sprayed at 0.2 MPa. Under the conditions, development was performed for 120 seconds, and heat curing was performed at 150 ° C for 60 minutes to obtain an evaluation sample for forming a cured coating film. On the obtained evaluation sample, a substrate with a copper foil of 35 μm (both sides of a copper-clad elastic substrate) attached to both sides of an 18 μm polyurethane film was loaded, and a circle with a diameter of 12 mm was further loaded on the substrate and the bottom surface was smooth. 1kg weight. In this state, the copper-coated elastic substrate on both sides was pulled apart approximately 10 cm in parallel, and the presence or absence of black marks on the coating film was evaluated by the following criteria.

○: No black marks

△: There are black marks with a width of 1 mm or less

×: There are black marks with a width exceeding 1 mm or plural black marks with a width of 1 mm or less

<Reflectivity>

The composition of each Example and Comparative Example was screen-coated on a copper solid FR-4 substrate with a thickness of 1.6 mm, dried at 80 ° C. for 30 minutes, and cooled to room temperature. After that, use a contact opening exposure device equipped with an ultra-high pressure mercury lamp (short arc lamp 5KW) to perform full exposure at the most appropriate exposure amount. A 1% by mass Na ₂ CO ₃ aqueous solution at 30 ° C is sprayed at a pressure of 0.2 MPa. Development was performed under conditions for 120 seconds, and heat curing was performed at 150 ° C. for 60 minutes to obtain an evaluation sample for forming a cured coating film. With respect to the obtained evaluation sample, the reflectance (%) of the coating film surface at 360 to 740 nm was measured with a spectrophotometer (CM-2600d, manufactured by Konicaminolta).

<Resolution>

The composition of each example and comparative example was screen-coated on a copper solid FR-4 substrate with a thickness of 1.6 mm so as to have a dry film thickness of 20 μm, dried at 80 ° C. for 30 minutes, and cooled to room temperature. For this substrate, a contact opening exposure device equipped with an ultra-high-pressure mercury lamp (short-arc lamp 5KW) was used for exposure at the most appropriate exposure amount and using a negative pattern with a line width of 100 μm in the light-shielding portion. A mass% Na ₂ CO ₃ aqueous solution was developed under the condition of a spray pressure of 0.2 MPa for 120 seconds, and heat-cured at 150 ° C. for 60 minutes as an evaluation sample. The line width removed by the obtained evaluation sample was measured with an optical microscope and evaluated by the following evaluation criteria.

○: The width of the removed line is 70 μm or more

△: The width of the removed line is 50 μm or more

×: The width of the removed line is less than 50 μm

<Glossiness>

The compositions of each example and comparative example were screen-coated on a 1.6 mm thick copper solid FR-4 substrate, dried at 80 ° C. for 30 minutes, and cooled to room temperature. After that, using a contact opening exposure device equipped with an ultra-high pressure mercury lamp (short arc lamp 5KW), full exposure was performed at the most appropriate exposure amount, and a 1% by mass Na ₂ CO ₃ aqueous solution at 30 ° C. was sprayed at a pressure of 0.2 MPa. Development was performed under conditions for 120 seconds, and heat curing was performed at 150 ° C. for 60 minutes to obtain an evaluation sample for forming a hardened coating film. About the obtained evaluation sample, 60-degree specular reflectance was measured using micro-TRI-gloss (made by BYK. Japan).

<Flammability>

The composition of each example and comparative example was screen-coated on a 25 μm-thick polyurethane film (Kapton 100H), dried at 80 ° C. for 20 minutes, and cooled to room temperature. Further, the inner surface was completely coated with screen printing in the same manner, dried at 80 ° C. for 20 minutes, and cooled to room temperature to obtain a double-sided coated substrate. On this substrate, an exposure device (HMW-680-GW20) equipped with a metal halide lamp was used to fully expose the solder resist at the most appropriate exposure amount. A 1% by weight Na ₂ CO ₃ aqueous solution at 30 ° C was sprayed at a pressure of 0.2 MPa. Under the conditions, development was performed for 120 seconds, and heat curing was performed at 150 ° C for 60 minutes, which were used as evaluation samples. The flame retardant evaluation sample was subjected to a thin material vertical combustion test based on the UL94 standard. The evaluation is for the UL94 specification and is expressed as VTM-0 or VTM-1.

<Foldability>

The composition of each example and comparative example was screen-coated on a 25 μm-thick polyimide film (Kapton 100H manufactured by TORAY. Du Pont), dried at 80 ° C. for 30 minutes, and cooled to room temperature. After that, use a contact opening exposure device equipped with an ultra-high pressure mercury lamp (short arc lamp 5KW) to perform full exposure at the most appropriate exposure amount. A 1% by mass Na ₂ CO ₃ aqueous solution at 30 ° C is sprayed at a pressure of 0.2 MPa. Development was performed under conditions for 120 seconds, and heat curing was performed at 150 ° C. for 60 minutes to obtain an evaluation sample with a cured coating film formed. For the obtained evaluation sample, after having a gap of R = 0.8mm, it was folded once at 180 °, and the occurrence of cracks in the hardened coating film at this time was visually observed and observed with an optical microscope (magnification × 200). Assessment basis.

○: No breakage even when folded three times

△: No crack occurred once, but crack occurred when folded 2 to 3 times

×: Rupture occurred when folded once

<Electrical Characteristics>

The composition of the examples and comparative examples was coated with a comb-shaped electrode B test piece of IPC B-25 by screen printing, and dried at 80 ° C. for 30 minutes and cooled to room temperature. After that, the exposure device was opened using a contact equipped with an ultra-high pressure mercury lamp (short arc lamp 5KW), and full exposure was performed at the most appropriate exposure amount. A 1% by mass Na ₂ CO ₃ aqueous solution at 30 ° C was sprayed at a pressure of 0.2 MPa. Development was performed under the conditions for 120 seconds, and heat curing was performed at 150 ° C for 60 minutes to obtain an evaluation sample. A bias voltage of 100 V DC was applied to the comb electrode, and the presence or absence of displacement of the constant temperature and humidity bath at 85 ° C and 85% RH after 1,000 hours was confirmed by the following evaluation criteria.

○: No change at all

△: Only change

×: displacement occurs

* 32: Urethane acrylate with a weight average molecular weight of 4,900 and 10 functional groups and urethane acrylate with a weight average molecular weight of 50,000 and 15 functional groups

From the results shown in Tables 1 and 2 above, it can be seen that in the case of the photosensitive resin composition of the example, it is difficult to produce friction marks on the cured product. On the other hand, in Comparative Examples 1 and 2 which did not contain a urethane (meth) acrylate having 6 or more (B) functional groups, frictional marks were easily generated on the cured product.

Claims (6)

A photosensitive resin composition comprising (A) a carboxyl group-containing resin, (B) a urethane (meth) acrylate having 6 or more functional groups, (C) a photopolymerization initiator, and ( D) Titanium oxide, wherein the (A) carboxyl group-containing resin is a carboxyl group-containing resin including a urethane structure. The photosensitive resin composition according to claim 1, wherein the weight average molecular weight of the urethane (meth) acrylate having 6 or more functional groups (B) is 1,500 to 200,000. The photosensitive resin composition according to claim 1 or 2, further comprising at least one of a metal hydroxide and a phosphorus-based compound. A dry film comprising a photosensitive resin composition according to any one of claims 1 to 3 coated on a film and dried. A cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 3 or the dried film according to claim 4. A printed wiring board having a hardened body as claimed in claim 5.