CN106716251B

CN106716251B - Photosensitive resin composition, dry film and cured coating film thereof, and printed wiring board using same

Info

Publication number: CN106716251B
Application number: CN201580052818.0A
Authority: CN
Inventors: 中岛孝典; 加藤贤治; 嶋宫步
Original assignee: Taiyo Ink Mfg Co Ltd
Current assignee: Taiyo Holdings Co Ltd
Priority date: 2014-09-30
Filing date: 2015-09-30
Publication date: 2021-11-05
Anticipated expiration: 2035-09-30
Also published as: CN106716251A; JP6463370B2; WO2016052653A1; KR20170063859A; JPWO2016052653A1; KR101929140B1; CN113848681A

Abstract

Providing: a photosensitive resin composition which is excellent in sensitivity and developability, and which is excellent in the suppression of the decrease in reflectance of a cured product due to light irradiation or heat, and is also excellent in the dry-to-touch property, the suppression of discoloration, and the sagging prevention effect, a dry film and a cured coating film thereof, and a printed wiring board using the same. A photosensitive resin composition, comprising: (A) a carboxyl group-containing resin having a styrene skeleton, (B) a photopolymerization initiator, and (C) an inorganic filler, wherein the carboxyl group-containing resin having a styrene skeleton (A) has a weight average molecular weight of 10000 to 50000 and an acid value of 80 to 200 mgKOH/g.

Description

Photosensitive resin composition, dry film and cured coating film thereof, and printed wiring board using same

Technical Field

The present invention relates to a photosensitive resin composition, a dry film and a cured coating film thereof, and a printed circuit board using the same.

Background

In recent years, in solder resists for consumer printed circuit boards and industrial printed circuit boards, from the viewpoint of high precision and high density, liquid developing type solder resists are used which are developed after ultraviolet irradiation to form an image and finally cured (completely cured) by either heat or light irradiation. In addition, in response to the increase in density of printed wiring boards accompanied by the reduction in weight and size of electronic devices, solder resists are required to have improved workability and high performance.

As a resin composition that satisfies the above-described required characteristics and realizes suppression of the protective film from becoming yellow when the protective film is exposed to high temperatures, for example, patent document 1 discloses a photosensitive composition containing a carboxyl group-containing resin having an aromatic ring. Patent document 2 discloses a white-light curable/thermosetting solder resist composition containing a carboxyl group-containing resin having no aromatic ring, which is one of the purposes of suppressing deterioration (yellowing) of the resin by light.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-

Patent document 2: japanese laid-open patent publication No. 2007-322546

Disclosure of Invention

Problems to be solved by the invention

However, when the resin compositions as described in patent documents 1 and 2 are used, there is still room for improvement in the finger-touch drying property (non-stick property) and the prevention of sagging after application to a substrate. In this respect, it is known that a sag preventing effect is obtained by using a specific modified urea or a saturated fatty acid in a composition, but there is a problem that discoloration of a resin occurs.

Accordingly, an object of the present invention is to provide: a photosensitive resin composition which is excellent in sensitivity and developability, and which is excellent in the suppression of the decrease in reflectance of a cured product due to light irradiation or heat, and is also excellent in the dry-to-touch property, the suppression of discoloration, and the sagging prevention effect, a dry film and a cured coating film thereof, and a printed wiring board using the same.

Means for solving the problems

That is, the photosensitive resin composition of the present invention is characterized by containing: (A) a carboxyl group-containing resin having a styrene skeleton, (B) a photopolymerization initiator, and (C) an inorganic filler, wherein the carboxyl group-containing resin having a styrene skeleton (A) has a weight average molecular weight of 10000 to 50000 and an acid value of 80 to 200 mgKOH/g.

In the photosensitive resin composition of the present invention, (C) is preferably titanium oxide, and (C) is more preferably rutile titanium oxide.

Further, the photosensitive resin composition of the present invention preferably contains a thermosetting component.

The dry film of the present invention is obtained by applying the above-mentioned arbitrary photosensitive resin composition to a film and drying the film.

The cured film of the present invention is obtained by curing the above-mentioned arbitrary photosensitive resin composition or a dry film obtained by applying the above-mentioned arbitrary photosensitive resin composition to a film and drying the film.

The printed wiring board of the present invention is characterized by comprising the cured coating film.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided: a photosensitive resin composition which is excellent in sensitivity and developability, and which is excellent in the suppression of the decrease in reflectance of a cured product due to light irradiation or heat, and is also excellent in the dry-to-touch property, the suppression of discoloration, and the sagging prevention effect, a dry film and a cured coating film thereof, and a printed wiring board using the same.

Detailed Description

Hereinafter, embodiments of the present invention will be specifically described.

The photosensitive resin composition of the present invention is characterized by containing: (A) a carboxyl group-containing resin having a styrene skeleton, (B) a photopolymerization initiator, and (C) an inorganic filler, wherein the carboxyl group-containing resin having a styrene skeleton (A) has a weight average molecular weight of 10000 to 50000 and an acid value of 80 to 200 mgKOH/g.

The components of the photosensitive resin composition of the present invention are described in detail below.

(A) carboxyl group-containing resin having styrene skeleton >

(A) The carboxyl group-containing resin having a styrene skeleton is a resin having a carboxyl group in a molecule and having no photosensitive group such as an ethylenically unsaturated bond, and has a styrene skeleton in a molecule, a weight average molecular weight of 10000 to 50000, and an acid value of 80 to 200 mgKOH/g. Such a carboxyl group-containing resin having a styrene skeleton can be synthesized by copolymerizing styrene as an essential monomer. By using the carboxyl group-containing resin having the above physical properties, the cured coating film formed from the photosensitive resin composition of the present invention has good finger-touch drying properties and sagging prevention effect.

Specific examples of (a) the carboxyl group-containing resin having a styrene skeleton include: a carboxyl group-containing resin (both oligomer and polymer) obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound selected from styrene, α -methylstyrene, lower alkyl (meth) acrylate, isobutylene and the like. The lower alkyl group is an alkyl group having 1 to 5 carbon atoms.

In the photosensitive resin composition of the present invention, when the weight average molecular weight of the (a) carboxyl group-containing resin having a styrene skeleton differs depending on the resin skeleton and is 10000 or more and 50000 or less, the sagging prevention effect is excellent. When the weight average molecular weight is 10000 or more, the sag preventing effect is improved, the dry-to-touch property (non-stick property) is improved, the moisture resistance of the coating film after exposure is improved, and the film loss at the time of development and the decrease in resolution can be suppressed. When the weight average molecular weight is 50000 or less, the developing property is improved and the storage stability is also excellent in addition to the above-mentioned sagging prevention effect. More preferably 10000 or more and 25000 or less, and still more preferably 10000 or more and 15000 or less.

In the photosensitive resin composition of the present invention, the acid value of the carboxyl group-containing resin (A) having a styrene skeleton is 80 to 200 mgKOH/g. More preferably 100 to 160 mgKOH/g. This is because the (a) carboxyl group-containing resin having a styrene skeleton has an acid value of 80mgKOH/g or more, and thus can have a high softening point, is extremely excellent in non-tackiness, and is also excellent in developability. On the other hand, when the acid value of the carboxyl group-containing resin (a) having a styrene skeleton is 200mgKOH/g or less, the crosslinking density can be adjusted to a suitable value, and a good coating film can be obtained without generating stress during curing.

In the photosensitive resin composition of the present invention, (a) the carboxyl group-containing resin having a styrene skeleton has a styrene skeleton, and thus has an aromatic ring, but surprisingly, the decrease in reflectance by light irradiation or heat of a cured product is suppressed, and discoloration is suppressed, and at the same time, the photosensitive resin composition is excellent in developability and finger-touch drying property. The ratio of the styrene skeleton in the molecule is preferably 10 to 80 mol%, more preferably 10 to 60 mol%, and further preferably 10 to 50 mol%. That is, in the synthesis of the carboxyl group-containing resin having a styrene skeleton (a), styrene is preferably used in an amount of 30 to 60 mol% based on the total amount of monomers. In the molecule, when the styrene skeleton ratio of the carboxyl group-containing resin having a styrene skeleton (a) is 10 mol% or more, the compatibility with other components becomes good. In addition, in the molecule, by making it to be 80 mol% or less, the developability becomes better.

The resin produced by suspension polymerization of the carboxyl group-containing resin (a) having a styrene skeleton is a high-molecular-weight resin. As a result, a composition using the resin is preferable in terms of excellent finger-touch dryness (non-stick property). Generally, the carboxyl group-containing resin (a) having a styrene skeleton is produced by suspension polymerization and has a high molecular weight, but when properties such as screen printing suitability, dry-to-touch property, and developability are considered, the weight average molecular weight needs to be suppressed to a range of 10000 to 50000. Therefore, in the case of controlling the molecular weight, it is preferable to use a chain transfer agent in the synthesis of the carboxyl group-containing resin having a styrene skeleton (a).

As the chain transfer agent used in the synthesis of such a resin, a known and commonly used one can be used, and among them, MSD (α -methylstyrene dimer) and n-DM (n-dodecylmercaptan) are preferable.

In addition, in order to promote polymerization, a polymerization initiator is preferably used in the synthesis of the carboxyl group-containing resin having a styrene skeleton (a). Examples of the polymerization initiator include: BPO (benzoyl peroxide), tert-butyl peroxy-2-ethylhexanoate, AMBN (2, 2' -azobis (2-methylbutyronitrile)), and the like. Among them, BPO (benzoyl peroxide) is preferable. The amount of the polymerization initiator to be added is preferably 0.1 to 10 parts by mass in 100 parts by mass of the resin in terms of solid content and more preferably 0.1 to 4 parts by mass in 100 parts by mass of the resin in terms of solid content when the (a) carboxyl group-containing resin having a styrene skeleton is synthesized.

In the photosensitive resin composition of the present invention, a mixture of (a) a carboxyl group-containing resin having a styrene skeleton and a carboxyl group-containing resin other than (a) may be used.

(carboxyl group-containing resin other than (A))

The carboxyl group-containing resin other than (a) used in the photosensitive resin composition of the present invention is particularly preferably a carboxyl group-containing resin having no aromatic ring, from the viewpoint of excellent non-stick properties under severe conditions. In this case, as long as the resin containing a carboxyl group has no aromatic ring, a photosensitive carboxyl group-containing resin having 1 or more photosensitive unsaturated double bonds per se and a carboxyl group-containing resin having no photosensitive unsaturated double bonds can be arbitrarily used, and the resin is not limited to a specific one. In particular, those having no aromatic ring (either oligomers or polymers) among the resins listed below can be suitably used.

Namely, the following resins: (1) a carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid and a compound having an unsaturated double bond; (2) a photosensitive carboxyl group-containing resin obtained by reacting a carboxyl group-containing (meth) acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in 1 molecule; (3) a photosensitive carboxyl group-containing resin obtained by reacting a copolymer of a compound having 1 epoxy group and an unsaturated double bond in 1 molecule and a compound having an unsaturated double bond with an unsaturated monocarboxylic acid, and reacting a secondary hydroxyl group formed by the reaction with a saturated or unsaturated polybasic acid anhydride; (4) a photosensitive hydroxyl-and carboxyl-containing resin obtained by reacting a hydroxyl-containing polymer with a saturated or unsaturated polybasic acid anhydride and then reacting a carboxylic acid produced by the reaction with a compound having 1 epoxy group and 1 unsaturated double bond in each molecule.

Among these, the photosensitive carboxyl group-containing resin of the above (2), that is, a copolymer resin having a carboxyl group obtained by the reaction of (a) a carboxyl group-containing (meth) acrylic copolymer resin and (b) 1a compound having an oxirane ring and an ethylenically unsaturated group in the molecule is preferable.

(a) The carboxyl group-containing (meth) acrylic copolymer resin can be obtained by copolymerizing a (meth) acrylate with a compound having 1 unsaturated group and at least 1 carboxyl group in 1 molecule. Examples of the (meth) acrylate constituting the copolymer resin (a) include: hydroxyl group-containing (meth) acrylates such as alkyl (meth) acrylates including methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate and hexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and caprolactone-modified 2-hydroxyethyl (meth) acrylate, and glycol-modified (meth) acrylates such as methoxy diethylene glycol (meth) acrylate, ethoxy diethylene glycol (meth) acrylate, isooctoxy diethylene glycol (meth) acrylate, phenoxy triethylene glycol (meth) acrylate, methoxy triethylene glycol (meth) acrylate and methoxy polyethylene glycol (meth) acrylate. Among them, methyl (meth) acrylate and caprolactone-modified 2-hydroxyethyl (meth) acrylate are preferable. These may be used alone or in combination of 2 or more. In the present specification, the term (meth) acrylate refers to a general term of acrylate and methacrylate, and the same applies to other similar expressions.

Further, as the compound having 1 unsaturated group and at least 1 carboxyl group in 1 molecule constituting the copolymer resin (a), there can be mentioned: examples of the modified unsaturated monocarboxylic acid include acrylic acid, methacrylic acid, modified unsaturated monocarboxylic acids obtained by extending the chain between an unsaturated group and a carboxylic acid, such as β -carboxyethyl (meth) acrylate, 2-acryloyloxyethyl succinate, 2-acryloyloxyethyl hexahydrophthalic acid, unsaturated monocarboxylic acids having an ester bond by lactone modification, modified unsaturated monocarboxylic acids having an ether bond, and substances containing 2 or more carboxyl groups in the molecule, such as maleic acid. Among them, methacrylic acid is preferable. These may be used alone, or 2 or more kinds may be mixed and used.

The compound (b)1 having an oxirane ring and an ethylenically unsaturated group in the molecule may be a compound having an ethylenically unsaturated group and an oxirane ring in 1 molecule, and examples thereof include: glycidyl (meth) acrylate, α -methylglycidyl (meth) acrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate, 3, 4-epoxycyclohexylethyl (meth) acrylate, 3, 4-epoxycyclohexylbutyl (meth) acrylate, 3, 4-epoxycyclohexylmethyl acrylate, and the like. Among them, 3, 4-epoxycyclohexylmethyl (meth) acrylate is preferable. These compounds (b)1 having an oxirane ring and an ethylenically unsaturated group in the molecule may be used alone or in combination of 2 or more.

The carboxyl group-containing resin other than (A) preferably has an acid value in the range of 50 to 200 mgKOH/g. When the acid value is 50mgKOH/g or more, it becomes easy to remove the unexposed portion of the coating film of the composition with a weak alkali aqueous solution. When the acid value is 200mgKOH/g or less, the cured film has excellent water resistance and electrical properties. The weight average molecular weight of the carboxyl group-containing resin other than (A) is preferably in the range of 5000 to 100000. When the weight average molecular weight is 5000 or more, the touch dryness of a coating film of the photosensitive resin composition tends to be remarkably improved. Further, a weight average molecular weight of 100000 or less is preferable because the developability and storage stability of the photosensitive resin composition tend to be remarkably good.

[ photopolymerization initiator (B) ]

In the photosensitive resin composition of the present invention, any known photopolymerization initiator can be used as the photopolymerization initiator (B), and among them, an oxime ester type photopolymerization initiator having an oxime ester group, an α -aminoacetophenone type photopolymerization initiator, and an acylphosphine oxide type photopolymerization initiator are preferable, and an acylphosphine oxide type photopolymerization initiator is more preferable. The photopolymerization initiator may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of oxime ester photopolymerization initiators that are commercially available include: CGI-325 manufactured by BASF JAPAN LTD, IRGACURE (registered trademark) OXE01, IRGACURE OXE02, N-1919 manufactured by ADEKA CORPORATION, and ADEKA ARKLS (registered trademark) NCI-831.

Further, a photopolymerization initiator having 2 oxime ester groups in the molecule can be suitably used, and specifically, an oxime ester compound having a carbazole structure represented by the following general formula can be exemplified.

(wherein X represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group), a naphthyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group), Y, Z each represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a halogen group, a phenyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group), a naphthyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, a naphthyl group, Alkylamino or dialkylamino substituted with an alkyl group having 1 to 8 carbon atoms), anthracenyl, pyridyl, benzofuranyl, benzothienyl, Ar represents an alkylene group having 1 to 10 carbon atoms, vinylene, phenylene, biphenylene, pyridylene, naphthylene, thiophene, anthracylene, thienylene, furylene, 2, 5-pyrrolediyl, 4 '-stilbenediyl, 4, 2' -styryl-diyl, and n is an integer of 0 or 1. )

Particularly preferred is an oxime ester type photopolymerization initiator in which X, Y is a methyl group or an ethyl group, Z is a methyl group or a phenyl group, n is 0, and Ar is a phenylene group, a naphthylene group, a thiophene group, or a thienylene group in the above formula.

The amount of oxime ester photopolymerization initiator added when used is preferably 0.01 to 5 parts by mass in terms of solid content, based on 100 parts by mass of the carboxyl group-containing resin having a styrene skeleton (A). When the amount is 0.01 part by mass or more, the photocurability on copper is good, the coating film is difficult to peel off, and the coating film properties such as chemical resistance are good. On the other hand, when the amount is 5 parts by mass or less, the light absorption on the surface of the coating film becomes good, and the deep curing property is improved. More preferably 0.5 to 3 parts by mass.

Specific examples of the α -aminoacetophenone-based photopolymerization initiator include: 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, 2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholino) phenyl ] -1-butanone, N-dimethylaminoacetophenone, and the like. Examples of commercially available products include: IRGACURE907, IRGACURE 369, IRGACURE 379, and the like, manufactured by BASF JAPAN LTD.

Specific examples of the acylphosphine oxide photopolymerization initiator include: monoacylphosphine oxide-based photopolymerization initiators such as 2,4, 6-trimethylbenzoyldiphenylphosphine oxide, bisacylphosphine oxide-based photopolymerization initiators such as bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide and bis (2, 6-dimethoxybenzoyl) -2,4, 4-trimethyl-pentylphosphine oxide, and the like. Among them, bisacylphosphine oxide photopolymerization initiators are preferable in terms of excellent suppression of discoloration. Commercially available monoacylphosphine oxide-based photopolymerization initiators manufactured by BASF JAPAN ltd. include IRGACURE TPO, and bisacylphosphine oxide-based photopolymerization initiators include IRGACURE 819.

The amount of each component to be used when the α -aminoacetophenone-based photopolymerization initiator or the acylphosphine oxide-based photopolymerization initiator is used is preferably 0.01 to 25 parts by mass in terms of solid content, based on 100 parts by mass of the carboxyl group-containing resin (a) having a styrene skeleton. When the amount is 0.01 part by mass or more, photocurability on copper is good, and the coating film is less likely to peel off, as in the case of using an oxime ester photopolymerization initiator, and deterioration of coating film characteristics such as chemical resistance can be suppressed. On the other hand, when the amount is 25 parts by mass or less, the amount of outgas is reduced, and further, the light absorption on the surface of the coating film becomes good, and the deep curing property is improved. More preferably 0.5 to 20 parts by mass.

< inorganic Filler >

Examples of the inorganic filler (C) used in the photosensitive resin composition of the present invention include: titanium oxide, zinc oxide, basic lead carbonate, basic lead sulfate, zinc sulfide, antimony oxide, aluminum hydroxide, barium sulfate, and the like. The titanium oxide may be rutile type titanium oxide or anatase type titanium oxide, and rutile type titanium oxide is preferably used. Similarly, anatase-type titanium oxide, which is titanium oxide, has a higher whiteness than rutile-type titanium oxide and is often used as a white pigment, but anatase-type titanium oxide has photocatalytic activity and, therefore, discoloration of the resin in the insulating resin composition may be caused particularly by light irradiated from the LED. On the other hand, rutile titanium oxide is slightly inferior in whiteness to anatase titanium oxide, but hardly has photoactivity, and thus can significantly suppress deterioration (yellowing) of a resin by light due to photoactivity of titanium oxide, and is also stable. Therefore, when the insulating layer of the printed wiring board on which the LED is mounted is used as a white colorant, high reflectance can be maintained for a long period of time.

As the rutile type titanium oxide, known rutile type titanium oxide can be used. The rutile titanium oxide can be produced by two methods, namely a sulfuric acid method and a chlorine method, and in the present invention, any method can be suitably used. The sulfuric acid method is a method for producing rutile titanium oxide by dissolving ilmenite ore and titanium slag as raw materials in concentrated sulfuric acid to separate iron components as iron sulfate, hydrolyzing the solution to obtain a hydroxide precipitate, and calcining the hydroxide precipitate at high temperature. On the other hand, the chlorine method is a method for producing rutile-type titanium oxide by using synthetic rutile or natural rutile as a raw material, reacting the raw material with chlorine gas and carbon at a high temperature of about 1000 ℃ to synthesize titanium tetrachloride, and oxidizing the titanium tetrachloride. Among these, rutile titanium oxide produced by the chlorine method is particularly remarkable in the effect of suppressing resin deterioration (yellowing) due to heat, and is more preferably used in the present invention.

In addition, titanium oxide whose surface is treated with hydrous aluminum oxide or aluminum hydroxide may also be used.

Further, the titanium oxide may contain sulfur, and the amount of sulfur is preferably 100ppm or less, more preferably 60ppm or less. This is because when the sulfur content is 100ppm or less, discoloration of the peripheral portion due to the generated sulfur gas does not occur.

Barium sulfate is preferably used because of its excellent discoloration inhibition, non-stick property, sagging prevention effect, and developability. Among them, it is preferable to add the pigment as an extender pigment instead of the coloring pigment.

The inorganic filler can be used alone in 1, also can be combined with more than 2.

The amount of the inorganic filler to be blended is not particularly limited, and is preferably 50 to 300 parts by mass, more preferably 70 to 250 parts by mass, in terms of solid content, per 100 parts by mass of the carboxyl group-containing resin (a) having a styrene skeleton.

The invention may also be supplemented with optical brighteners. The fluorescent whitening agent is a substance capable of exhibiting no discoloration while increasing the whiteness of a cured product of the composition. In the present invention, the use of titanium oxide, particularly rutile titanium oxide, as an inorganic filler and a fluorescent whitening agent in the photosensitive resin composition enables the cured coating film to have a high reflectance.

The fluorescent whitening agent absorbs light with the wavelength of 200-400 nm and releases light with the wavelength of 400-500 nm. Examples of such fluorescent whitening agents include: benzoxazole derivatives, coumarin derivatives, styryl biphenyl derivatives, pyrazolone derivatives, bis (triazinylamino) stilbenedisulfonic acid derivatives, and the like. Among them, benzoxazole derivatives are preferable. As the substituent group of the benzoxazole derivative, a butyl group, an octyl group, a naphthyl group, a thiophene, and a stilbene are preferable.

(thermosetting component)

Further, a thermosetting component may be added to the photosensitive resin composition of the present invention. Examples of the thermosetting component used in the present invention include: and known and commonly used thermosetting resins such as polyfunctional epoxy compounds, blocked isocyanate compounds, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclic carbonate compounds, polyfunctional oxetane compounds, episulfide resins, and the like. Among these, the preferable thermosetting component is a thermosetting component having at least 1 of a plurality of cyclic ether groups and cyclic thioether groups (hereinafter, simply referred to as cyclic (thio) ether groups) in 1 molecule.

Thermosetting components having a cyclic (thio) ether group are commercially available in many types, and various properties can be imparted to the thermosetting components depending on the structure.

Such a thermosetting component having a plurality of cyclic (thio) ether groups in the molecule is a compound having any one or two groups of a cyclic ether group or a cyclic thioether group having two or more three-membered, four-membered or five-membered rings in the molecule, and examples thereof include: a polyfunctional oxetane compound having a plurality of oxetanyl groups in the molecule, an episulfide resin having a plurality of thioether groups in the molecule, and the like.

In the photosensitive resin composition of the present invention, a compound having a plurality of isocyanate groups or blocked isocyanate groups in 1 molecule may be added as a thermosetting component in order to improve the curability of the composition and the toughness of the resulting cured coating film. Examples of the compound having a plurality of isocyanate groups or blocked isocyanate groups in 1 molecule include: a polyisocyanate compound which is a compound having a plurality of isocyanate groups in 1 molecule, or a blocked isocyanate compound which is a compound having a plurality of blocked isocyanate groups in 1 molecule.

As the polyisocyanate compound, for example, aromatic polyisocyanate, aliphatic polyisocyanate or alicyclic polyisocyanate can be used. Specific examples of the aromatic polyisocyanate include: 4, 4' -diphenylmethane diisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, naphthalene-1, 5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, and 2, 4-toluene diisocyanate dimer. Specific examples of the aliphatic polyisocyanate include: tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate. Specific examples of the alicyclic polyisocyanate include bicycloheptane triisocyanate. And adducts, biuret products and isocyanurate products of the above-mentioned isocyanate compounds.

The blocked isocyanate group contained in the blocked isocyanate compound is a group in which an isocyanate group is protected by a reaction with a blocking agent and temporarily deactivated. When heated to a predetermined temperature, the blocking agent is dissociated to generate an isocyanate group.

As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent may be used. Examples of the isocyanate compound capable of reacting with the blocking agent include: isocyanurate type, biuret type, adduct type, etc. As the isocyanate compound, for example, aromatic polyisocyanate, aliphatic polyisocyanate, or alicyclic polyisocyanate can be used. Specific examples of the aromatic polyisocyanate, the aliphatic polyisocyanate, and the alicyclic polyisocyanate include the compounds described above.

Examples of the isocyanate blocking agent include: phenol-based end-capping agents such as phenol, cresol, xylenol, chlorophenol, and ethylphenol; lactam-based blocking agents such as epsilon-caprolactam, delta-valerolactam, gamma-butyrolactam and beta-propiolactam; an active methylene-based blocking agent such as ethyl acetoacetate or acetylacetone; alcohol-based blocking agents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl ether, methyl glycolate, butyl glycolate, diacetone alcohol, methyl lactate, and ethyl lactate; oxime blocking agents such as formaldoxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monoxime, and cyclohexane oxime; thiol-based blocking agents such as butanethiol, hexanethiol, tert-butylmercaptan, thiophenol, methylthiophenol, and ethylthiophenol; acid amide-based blocking agents such as acetamide and benzamide; imide-based capping agents such as succinimide and maleimide; amine-based blocking agents such as xylidine, aniline, butylamine, and dibutylamine; imidazole-based capping agents such as imidazole and 2-ethylimidazole; and imine-based blocking agents such as methylene imine and propylene imine.

As the blocked isocyanate compound, commercially available ones can be used, and examples thereof include: sumidule BL-3175, BL-4165, BL-1100, BL-1265, Desmodule TPLS-2957, TPLS-2062, TPLS-2078, TPLS-2117, Desmoutherm 2170, Desmoutherm 2265 (above, trade name manufactured by Sumika Bayer Urethane Co., Ltd.), Coronate 2512, Cornate 2513, Cornate 2520 (above, trade name manufactured by Nippon polyurethane Industrial Co., Ltd.), B-830, B-815, B-846, B-870, B-874, B-882 (above, Mitsui Takeda Chemical Co., Ltd., trade name manufactured by Ltd.), TPA-B80E, 17B-60PX, E402-B80T (above, produced by Asahi Kasei s Chemical Co., Ltd.), and the like. Sumidule BL-3175 and BL-4265 were obtained by using methyl ethyl ketoxime as a blocking agent.

The 1 molecule having a plurality of isocyanate groups or blocked isocyanate groups of compounds can be used alone in 1 kind, or can be combined with 2 or more kinds.

The amount of the compound having a plurality of isocyanate groups or blocked isocyanate groups in 1 molecule is 1 to 100 parts by mass, more preferably 2 to 70 parts by mass in terms of solid content per 100 parts by mass of the carboxyl group-containing resin having a styrene skeleton (A). When the amount of the above-mentioned component is 1 part by mass or more, sufficient toughness of the coating film can be obtained. On the other hand, when the amount is 100 parts by mass or less, the storage stability is good.

In addition, an amino resin such as a melamine derivative or benzoguanamine derivative may be added as a thermosetting component to the photosensitive resin composition of the present invention. Examples of such thermosetting components include: methylol melamine compounds, methylol benzoguanamine compounds, methylol glycoluril compounds, methylol urea compounds, alkoxymethylated melamine compounds, alkoxymethylated benzoguanamine compounds, alkoxymethylated glycoluril compounds, alkoxymethylated urea compounds, and the like. The kind of the alkoxymethyl group is not particularly limited, and examples thereof include a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, and a butoxymethyl group. Particularly, a melamine derivative having a formalin concentration of 0.2% or less which is friendly to the human body and environment is preferable. The thermosetting component can be used alone in 1 kind, also can be combined with 2 or more kinds.

Examples of commercially available products of these thermosetting components include: CYMEL 300, CYMEL 301, CYMEL 303, CYMEL 370, CYMEL 325, CYMEL 327, CYMEL 701, CYMEL 266, CYMEL 267, CYMEL 238, CYMEL 1141, CYMEL 272, CYMEL 202, CYMEL 1156, CYMEL 1158, CYMEL 1123, CYMEL 1170, CYMEL 1174, CYMEL UFR 65, CYMEL 300 (supra, manufactured by Mitsui Cyanamid Co. Ltd.), NIKALAC Mx-750, NIKALAC Mx-708, NIKALAC Mx-270, NIKALAC Mx-280, NIKALAC Mx-290, NIKALAC Mx-706, NIKALAC Mx-708, NIKALAC Mx-40, NIKALAC-31, NIKAC-11, NIKAC-30, NIKAC-Mx-30, NIKAC-750, NIKAC-100, NIKAC-LWAM-390, NIKAC 032, NIKAC Mx-750, NIKAC-750, NIKAM-11, NIKAC-W-200, NIKAM-W-750, NIKAM-W-750, NIKAC-W-K-W-K-W-750, NIKAM-W-K-W-K-W-K-W, NIKAM-W, and the like.

Examples of the polyfunctional epoxy compound include: JeR828, JeR834, JeR1001, JeR1004, Epiclon 840, Epiclon 850, Epiclon 1050, and Epiclon 2055, manufactured by Mitsubishi Chemical Co., Ltd., EPTOHTO YD-011, YD-013, YD-127, and YD-128, manufactured by Dow Chemical Company, D.E.R.317, D.E.R.331, D.E.R.661, and D.E.R.664, manufactured by Sumiepoxy ESA-011, ESA-014, ELA-115, and ELA-128, manufactured by Asahi Chemical Company, A.E.R.330, A.E.R.331, A.E.R.661, and A.E.R.664 (trade names) bisphenol epoxy resins; brominated epoxy resins such as jERYL903 manufactured by mitsubishi Chemical corporation, Epiclon 152 and Epiclon 165 manufactured by DIC corporation, EPOTOHTO YDB-400 and YDB-500 manufactured by eastern Chemical corporation, d.e.r.542 manufactured by Dow Chemical Company, Sumiepoxy ESB-400 and ESB-700 manufactured by sumitomo Chemical corporation, a.e.r.711 and a.e.r.714 manufactured by asahi Chemical corporation; JeR152 and JeR154 manufactured by Mitsubishi Chemical corporation, D.E.N.431 and D.E.N.438 manufactured by Dow Chemical Company, Epiclon N-730, Epiclon N-770 and Epiclon N-865 manufactured by DIC corporation, EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306 and NC-3000 manufactured by Tokyo Chemical Co., Ltd, Sumiepoxy ESCN-195X, ESCN-220 manufactured by Sumitomo Chemical Co., Ltd, A.E.R.ECN-235 and ECN-299 manufactured by Asahi Chemical Co., Ltd, YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7 and Epiclon-10 manufactured by Nippon Chemical Co., Ltd, YDCN-700-704 and EPO-700-704 manufactured by Shih Chemical Co., Ltd, Novolak type epoxy resins such as N-690 and N-695 (trade names); bisphenol F type epoxy resins such as Epiclon 830 manufactured by DIC corporation, jER807 manufactured by Mitsubishi chemical corporation, EPOTHTO YDF-170, YDF-175, YDF-2004 manufactured by Tokyo Kaisha, and the like (trade names); hydrogenated bisphenol A type epoxy resins such as EPOTOHTO ST-2004, ST-2007 and ST-3000 (trade name) manufactured by Tokyo chemical Co., Ltd; glycidyl amine type epoxy resins such as JeR604 manufactured by Mitsubishi chemical corporation, EPOTHTO YH-434 manufactured by Tokyo chemical Co., Ltd, and Sumiepoxy ELM-120 manufactured by Sumitomo chemical Co., Ltd; hydantoin type epoxy resins; alicyclic epoxy resins such as CELLOXIDE 2021 (trade name) manufactured by Daicel Corporation; trihydroxyphenyl methane type epoxy resins such as YL-933 manufactured by Mitsubishi Chemical corporation, T.E.N. manufactured by Dow Chemical Company, EPPN-501, EPPN-502, and the like (trade names); dixylenol-type or diphenol-type epoxy resins such as YL-6056, YX-4000 and YL-6121 (trade names) available from Mitsubishi chemical corporation, or a mixture thereof; bisphenol S type epoxy resins such as EBPS-200 manufactured by Nippon Kabushiki Kaisha, EPX-30 manufactured by ADEKA CORPORATION, and EXA-1514 (trade name) manufactured by DIC Kabushiki Kaisha; bisphenol a novolac type epoxy resins such as jER157S (trade name) manufactured by mitsubishi chemical corporation; tetrahydroxyphenylethane-type epoxy resins such as jERYL-931 (trade name) manufactured by Mitsubishi chemical corporation; heterocyclic epoxy resins such as TEPIC (trade name) manufactured by Nissan chemical industries, Ltd; diglycidyl phthalate resin such as BLEMMER DGT manufactured by japan fat and oil co; tetraglycidyl xylenol ethane resins such as ZX-1063 manufactured by Tokyo Kabushiki Kaisha; naphthyl group-containing epoxy resins such as ESN-190, ESN-360 available from Nippon Tekko chemical Co., Ltd, and HP-4032, EXA-4750, and EXA-4700 available from DIC Co., Ltd; epoxy resins having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by DIC; glycidyl methacrylate copolymer epoxy resins such as CP-50S, CP-50M manufactured by NOF CORPORATION; and a copolymerized epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; CTBN-modified epoxy resins (for example, YR-102, YR-450, manufactured by Tokyo Kabushiki Kaisha, etc.), etc., but the epoxy resins are not limited thereto. Among them, bisphenol a type epoxy resins, heterocyclic epoxy resins, bixylenol type epoxy resins, or mixtures thereof are particularly preferable.

These epoxy resins may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The amount of the epoxy resin is preferably in the range of 0.3 to 2.5 equivalents, more preferably 0.5 to 2.0 equivalents, relative to 1 equivalent of carboxyl groups of the carboxyl group-containing resin (a) having a styrene skeleton. When the thermosetting component having 2 or more cyclic (thio) ether groups in the molecule, particularly the amount of the epoxy resin blended is 0.3 or more, the carboxyl group hardly remains in the solder resist, and the heat resistance, alkali resistance, electrical insulation property, and the like become good. On the other hand, when the amount is 2.5 equivalents or less, the cyclic (thio) ether group having a low molecular weight is less likely to remain in the dried coating film, and the strength of the coating film and the like are improved.

(antioxidant)

The photosensitive resin composition of the present invention may contain an antioxidant such as a radical scavenger for neutralizing the generated radical, or a peroxide decomposer for decomposing the generated peroxide into a harmless substance and preventing generation of a new radical, in order to prevent oxidation. The antioxidant used in the present invention can prevent oxidative deterioration of a resin or the like and further suppress yellowing. Further, by adding an antioxidant, in addition to the above-described effects, it is possible to prevent halation due to a photocuring reaction of the photosensitive resin composition, stabilization of an opening shape, and the like, and to improve a process margin (process margin) at the time of producing the photosensitive resin composition. The antioxidant may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

Examples of the antioxidant which functions as a radical scavenger include: phenol compounds such as hydroquinone, 4-t-butylcatechol, 2-t-butylhydroquinone, hydroquinone monomethyl ether, 2, 6-di-t-butyl-p-cresol, 2-methylene-bis (4-methyl-6-t-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-hydroxybenzyl) benzene, 1,3, 5-tris (3 ', 5' -di-t-butyl-4-hydroxybenzyl) -s-triazine-2, 4,6- (1H,3H,5H) trione, quinone compounds such as p-methoxyphenol and benzoquinone, bis (2, and amine compounds such as 2,6, 6-tetramethyl-4-piperidyl) -sebacate and phenothiazine. Examples of commercially available products include: ADEKASTAB AO-30, ADEKASTAB AO-330, ADEKASTAB AO-20, ADEKASTAB LA-77, ADEKASTAB LA-57, ADEKASTAB LA-67, ADEKASTAB LA-68, ADEKASTAB LA-87 (trade name, manufactured by ADEKA CORPORATION), IRGANOX1010, IRGANOX 1035, IRGANOX 1076, IRGANOX 1135, TINUVIN 111FDL, TINUVIN 123, TINUVIN 144, TIVIN NUVIN 152, TINUVIN 292, TINUVIN 5100 (trade name, manufactured by BASF PAN LTD.), and the like.

Examples of the antioxidant which functions as a peroxide decomposer include: phosphorus-based compounds such as triphenyl phosphite, and sulfur-based compounds such as pentaerythritol tetrakis (lauryl thiopropionate), dilauryl thiodipropionate, and distearyl 3, 3' -thiodipropionate. Examples of commercially available products include: ADEKASTAB TPP (trade name, manufactured by ADEKA CORPORATION), MARK AO-412S (trade name, manufactured by ADEKA CORPORATION), Sumilizer TPS (trade name, manufactured by Sumitomo chemical Co., Ltd.), and the like.

The amount of the antioxidant to be used is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass in terms of solid content, based on 100 parts by mass of the carboxyl group-containing resin having a styrene skeleton (a). When the amount of the antioxidant is 0.01 part by mass or more, the effect of the addition of the antioxidant can be easily obtained. On the other hand, when the amount is 10 parts by mass or less, inhibition of photoreaction, poor development with an alkaline aqueous solution, deterioration of dry-to-touch property, and deterioration of coating film properties can be suppressed.

Further, the antioxidant, particularly the phenolic antioxidant, may exhibit further effects when used in combination with a heat-resistant stabilizer, and therefore, the photosensitive resin composition of the present invention may further contain a heat-resistant stabilizer.

Examples of the heat stabilizer include: phosphorus-based, hydroxylamine-based, and sulfur-based heat stabilizers. Commercially available products of these heat stabilizers include: IRGAFOX168, IRGAFOX12, IRGAFOX38, IRGASTAB PUR68, IRGASTAB PVC76, IRGASTAB FS301FF, IRGASTAB FS110, IRGASTAB FS210FF, IRGASTAB FS410FF, IRGANOX PS800FD, IRGANOX PS802FD, RECYCLOSTAB 411, RECYCLOSTAB 451AR, RECYCLOSSORB 550, RECYCLOBLEND 660 (above, manufactured by BASF JAPAN LTD., trade name), and the like. The heat stabilizer may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The amount of the heat stabilizer to be added is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass in terms of solid content, per 100 parts by mass of the carboxyl group-containing resin having a styrene skeleton (a).

(photoinitiation auxiliaries or sensitizers)

In addition to the above photopolymerization initiator, a photoinitiator aid or a sensitizer can be suitably used in the photosensitive resin composition of the present invention. Examples of the photoinitiator aid or sensitizer include: benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, xanthone compounds, and the like. These compounds may also be used as a photopolymerization initiator in some cases, and are preferably used in combination with the photopolymerization initiator. Further, the photoinitiator aid or sensitizer may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of benzoin compounds include: benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and the like.

Examples of the acetophenone compound include: acetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone, 1-dichloroacetophenone and the like.

Examples of the anthraquinone compound include: 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, etc.

Examples of the thioxanthone compound include: 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-chlorothioxanthone, 2, 4-diisopropylthioxanthone, and the like.

Examples of the ketal compound include: acetophenone dimethyl ketal, benzil dimethyl ketal, and the like.

Examples of the benzophenone compound include: benzophenone, 4-benzoyldiphenyl sulfide, 4-benzoyl-4 ' -methylbenzophenone sulfide, 4-benzoyl-4 ' -ethyldiphenyl sulfide, 4-benzoyl-4 ' -propyldiphenyl sulfide and the like.

Examples of the tertiary amine compound include ethanolamine compounds and compounds having a dialkylaminobenzene structure, and examples of commercially available compounds include: dialkylamino group-containing coumarin compounds such as 4,4 '-dimethylaminobenzophenone (NISSOCURE (registered trademark) MABP manufactured by shinoka chemical corporation) and 4, 4' -diethylaminobenzophenone (EAB manufactured by shinoka chemical industry co., ltd.), 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one (7- (diethylamino) -4-methylcoumarin), ethyl-4-dimethylaminobenzoate (KAYACURE (registered trademark) EPA manufactured by shinoka chemical corporation), ethyl-2-dimethylaminobenzoate (quantacu dmb manufactured by International Bio-synthetic, inc.), ethyl-4-dimethylaminobenzoate (n-butoxy) ethyl ester (quantacubea manufactured by International Bio-synthetic, inc.), isoamyl ethyl-p-dimethylaminobenzoate (rabi manufactured by shinoka chemical corporation, dmrebi), 2-ethylhexyl 4-dimethylaminobenzoate (Esolol 507 manufactured by VanDyk Corporation). The tertiary amine compound is preferably a compound having a dialkylaminobenzene structure, and particularly preferably a dialkylaminobenzophenone compound, a coumarin compound containing a dialkylamino group having a maximum absorption wavelength of 350 to 450nm, and a coumarin ketone.

As the dialkylaminobenzophenone compound, 4, 4' -diethylaminobenzophenone is preferable because of its low toxicity. Since the maximum absorption wavelength of the dialkylamino group-containing coumarin compound is in the ultraviolet region of 350 to 410nm, a colorless and transparent photosensitive composition with little coloration can be obtained, and a colored solder resist film reflecting the color of the colored pigment itself can be obtained by using the colored pigment. In particular, 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one is preferable because it exhibits an excellent sensitizing effect on laser light having a wavelength of 400 to 410 nm.

Of these, thioxanthone compounds and tertiary amine compounds are preferred. In particular, the deep-section curability can be improved by containing a thioxanthone compound.

The amount of the photoinitiator aid or sensitizer used is preferably 0.1 to 20 parts by mass in terms of solid content per 100 parts by mass of the carboxyl group-containing resin (a) having a styrene skeleton. When the amount of the photoinitiator aid or sensitizer is 0.1 part by mass or more, a good sensitizing effect can be obtained. On the other hand, when the amount is 20 parts by mass or less, the deep-part curability becomes good without increasing the light absorption on the surface of the coating film by the tertiary amine compound. More preferably 0.1 to 10 parts by mass.

The total amount of the photopolymerization initiator, the photoinitiator aid, and the sensitizer is preferably 35 parts by mass or less in terms of solid content, based on 100 parts by mass of the carboxyl group-containing resin (a) having a styrene skeleton. When the amount is 35 parts by mass or less, the decrease in deep-part curability due to the light absorption can be suppressed.

Since these photopolymerization initiator, photoinitiator aid, and sensitizer absorb a specific wavelength, the sensitivity may be lowered in some cases, and they may function as an ultraviolet absorber. However, these are not only used to increase the sensitivity of the composition. The light of a specific wavelength can be absorbed as required to improve the photoreactivity of the surface, and the line shape and the opening of the protective layer can be changed to be vertical, tapered, or inverted tapered, and the processing accuracy of the line width and the opening diameter can be improved.

(chain transfer agent)

In the photosensitive resin composition of the present invention, for the purpose of improving sensitivity, known and commonly used N-phenylglycine, phenoxyacetic acid, thiophenoxyacetic acid, mercaptothiazole, or the like can be used as a chain transfer agent. Examples of the chain transfer agent include: chain transfer agents having a carboxyl group such as mercaptosuccinic acid, mercaptoacetic acid, mercaptopropionic acid, methionine, cysteine, thiosalicylic acid, and derivatives thereof; chain transfer agents having hydroxyl groups such as mercaptoethanol, mercaptopropanol, mercaptobutanol, mercaptopropanediol, mercaptobutanediol, hydroxythiophenol, and derivatives thereof; 1-butanethiol, butyl-3-mercaptopropionate, methyl-3-mercaptopropionate, 2- (ethylenedioxy) diethylmercaptan, ethanethiol, 4-methylphenylthiol, dodecylmercaptan, propanethiol, butanethiol, pentanethiol, 1-octanethiol, cyclopentanethiol, cyclohexylmercaptan, thioglycerol, 4-thiobisbenzenethiol, and the like.

Further, as the chain transfer agent, a polyfunctional thiol compound may be used. Examples of the polyfunctional thiol compound include: aliphatic thiols such as 1, 6-hexanedithiol, 1, 10-decanedithiol, dimercaptodiethyl ether and dimercaptodiethyl sulfide, and aromatic thiols such as xylylenedithiol, 4' -dimercaptodiphenyl sulfide and 1, 4-benzenedithiol; polyhydric alcohol poly (thioglycolic acid) esters such as ethylene glycol bis (thioglycolic acid) ester, polyethylene glycol bis (thioglycolic acid) ester, propylene glycol bis (thioglycolic acid) ester, glycerol tris (thioglycolic acid) ester, trimethylolethane tris (thioglycolic acid) ester, trimethylolpropane tris (thioglycolic acid) ester, pentaerythritol tetrakis (thioglycolic acid) ester, dipentaerythritol hexa (thioglycolic acid) ester, and the like; poly (3-mercaptopropionic acid) esters of polyhydric alcohols such as ethylene glycol bis (3-mercaptopropionic acid) ester, polyethylene glycol bis (3-mercaptopropionic acid) ester, propylene glycol bis (3-mercaptopropionic acid) ester, glycerol tris (3-mercaptopropionic acid) ester, trimethylolethane tris (mercaptopropionic acid) ester, trimethylolpropane tris (3-mercaptopropionic acid) ester, pentaerythritol tetrakis (3-mercaptopropionic acid) ester, and dipentaerythritol hexa (3-mercaptopropionic acid) ester; poly (mercaptobutanoic acid) esters such as 1, 4-bis (3-mercaptobutanoyloxy) butane, 1,3, 5-tris (3-mercaptobutoxyethyl) -1,3, 5-triazine-2, 4,6(1H,3H,5H) -trione, pentaerythritol tetrakis (3-mercaptobutanoic acid) ester, and the like.

Examples of such commercially available products include: BMPA, MPM, EHMP, NOMP, MBMP, STMP, TMMP, PEMP, DPMP, and TEMPIC (made by Sakai chemical industry Co., Ltd.), Karenz MT-PE1, Karenz MT-BD1, and Karenz-NR1 (made by Showa Denko K.K.), and the like.

Further, as the chain transfer agent, a heterocyclic compound having a mercapto group may also be used. Examples of the heterocyclic compound having a mercapto group include: mercapto-4-butyrolactone (also known as 2-mercapto-4-butyrolactone), 2-mercapto-4-methyl-4-butyrolactone, 2-mercapto-4-ethyl-4-butyrolactone, 2-mercapto-4-thiobutyrolactone, 2-mercapto-4-butyrolactam, N-methoxy-2-mercapto-4-butyrolactam, N-ethoxy-2-mercapto-4-butyrolactam, N-methyl-2-mercapto-4-butyrolactam, N-ethyl-2-mercapto-4-butyrolactam, N- (2-methoxy) ethyl-2-mercapto-4-butyrolactam, and mixtures thereof, N- (2-ethoxy) ethyl-2-mercapto-4-butyrolactam, 2-mercapto-5-valerolactam, N-methyl-2-mercapto-5-valerolactam, N-ethyl-2-mercapto-5-valerolactam, N- (2-methoxy) ethyl-2-mercapto-5-valerolactam, N- (2-ethoxy) ethyl-2-mercapto-5-valerolactam, 2-mercaptobenzothiazole, 2-mercapto-5-methylthiothiadiazole, 3-mercapto-4-methyl-4H-1, 2, 4-triazole, and mixtures thereof, 5-methyl-1, 3, 4-thiadiazole-2-thiol, 1-phenyl-5-mercapto-1H-tetrazole, 2-mercapto-6-caprolactam, 2,4, 6-trimercapto-s-triazine (manufactured by Triplex corporation, trade name Zisnetf), 2-dibutylamino-4, 6-dimercapto-s-triazine (manufactured by Triplex corporation, trade name ZisnetDB), and 2-anilino-4, 6-dimercapto-s-triazine (manufactured by Triplex corporation, trade name ZisneAF).

Particularly preferred are mercaptobenzothiazole, 3-mercapto-4-methyl-4H-1, 2, 4-triazole, 5-methyl-1, 3, 4-thiadiazole-2-thiol, and 1-phenyl-5-mercapto-1H-tetrazole, since the developability of the photosensitive resin composition is not impaired. These chain transfer agents may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(Carbamate esterification catalyst)

In the photosensitive resin composition of the present invention, a urethane-forming catalyst may be added to promote a curing reaction of a hydroxyl group, a carboxyl group and an isocyanate group. As the urethane-forming catalyst, 1 or more kinds of urethane-forming catalysts selected from the group consisting of tin-based catalysts, metal chlorides, acetylacetone metal salts, metal sulfates, amine compounds, and amine salts are preferably used.

Examples of the tin-based catalyst include: organic tin compounds such as stannous octoate and dibutyltin dilaurate, inorganic tin compounds, and the like.

The metal chloride is a chloride of a metal consisting of Cr, Mn, Co, Ni, Fe, Cu, or Al, and examples thereof include cobaltous chloride, nickel chloride, and ferric chloride.

The metal acetylacetonate is a metal acetylacetonate composed of Cr, Mn, Co, Ni, Fe, Cu or Al, and examples thereof include: cobalt acetylacetonate, nickel acetylacetonate, iron acetylacetonate, and the like.

The metal sulfate is a sulfate of a metal consisting of Cr, Mn, Co, Ni, Fe, Cu, or Al, and examples thereof include copper sulfate.

Examples of the amine compound include: conventionally known triethylenediamine, N, N, N ', N' -tetramethyl-1, 6-hexanediamine, bis (2-dimethylaminoethyl) ether, N, N, N ', N' -pentamethyldiethylenetriamine, N-methylmorpholine, N-ethylmorpholine, N, N-dimethylethanolamine, dimorpholinodiethylether, N-methylimidazole, dimethylaminopyridine, triazine, N '- (2-hydroxyethyl) -N, N, N' -trimethyl-bis (2-aminoethyl) ether, N, N-dimethylhexanolamine, N, N-dimethylaminoethoxyethanol, N, N, N '-trimethyl-N' - (2-hydroxyethyl) ethylenediamine, N- (2-hydroxyethyl) -N, n ', N ' -tetramethyldiethylenetriamine, N- (2-hydroxypropyl) -N, N ' -tetramethyldiethylenetriamine, N, N, N ' -trimethyl-N ' - (2-hydroxyethyl) propanediamine, N-methyl-N ' - (2-hydroxyethyl) piperazine, bis (N, N-dimethylaminopropyl) amine, bis (N, N-dimethylaminopropyl) isopropanolamine, 2-aminoquinuclidine, 3-aminoquinuclidine, 4-aminoquinuclidine, 2-quinuclidine, 3-quinuclidine, 4-quinuclidine, 1- (2 ' -hydroxypropyl) imidazole, 1- (2 ' -hydroxypropyl) -2-methylimidazole, 1- (2 ' -hydroxyethyl) imidazole, 1- (2 '-hydroxyethyl) -2-methylimidazole, 1- (2' -hydroxypropyl) -2-methylimidazole, 1- (3 '-aminopropyl) imidazole, 1- (3' -aminopropyl) -2-methylimidazole, 1- (3 '-hydroxypropyl) imidazole, 1- (3' -hydroxypropyl) -2-methylimidazole, N-dimethylaminopropyl-N '- (2-hydroxyethyl) amine, N-dimethylaminopropyl-N', N '-bis (2-hydroxypropyl) amine, N-dimethylaminoethyl-N', n ' -bis (2-hydroxyethyl) amine, N-dimethylaminoethyl-N ', N ' -bis (2-hydroxypropyl) amine, melamine and/or benzoguanamine, and the like.

Examples of the amine salt include: amine salts of DBU (1, 8-diazabicyclo [5.4.0] undec-7-ene) with organic acid salts, and the like.

The amount of the urethane-forming catalyst to be added is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10.0 parts by mass in terms of solid content, per 100 parts by mass of the carboxyl group-containing resin (A) having a styrene skeleton.

(Heat curing catalyst)

When the epoxy resin or the thermosetting component having a plurality of cyclic (thio) ether groups in the molecule is used, a thermosetting catalyst is preferably contained. Examples of such a thermosetting catalyst include: imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, and 4-methyl-N, N-dimethylbenzylamine; hydrazide compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; phosphorus compounds such as triphenylphosphine, and the like. Further, examples of commercially available products include: 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all trade names of imidazole compounds), U-CAT (registered trademark) 3503N, U-CAT3502T (all trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATA SA102, U-CAT5002 (all bicyclic amidine compounds and salts thereof), manufactured by Sizhou chemical industry Co., Ltd. In particular, the epoxy resin composition is not limited to these, and any one of the epoxy resin composition and the oxetane compound composition may be used alone or in combination of 2 or more thereof, as long as the epoxy resin composition is a thermosetting catalyst, the oxetane compound is a thermosetting catalyst, or the epoxy resin composition promotes the reaction between at least 1 of the epoxy group and the oxetane group and the carboxyl group. Further, an s-triazine derivative such as guanamine, methylguanamine, benzoguanamine, melamine, 2, 4-diamino-6-methacryloyloxyethyl-s-triazine, 2-vinyl-2, 4-diamino-s-triazine, 2-vinyl-4, 6-diamino-s-triazine-isocyanuric acid adduct, or 2, 4-diamino-6-methacryloyloxyethyl-s-triazine-isocyanuric acid adduct may be used, and it is preferable to use these compounds which also function as an adhesion imparting agent in combination with the aforementioned heat curing catalyst.

The amount of the thermosetting catalyst to be blended is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15.0 parts by mass in terms of solid content, per 100 parts by mass of the carboxyl group-containing resin having a styrene skeleton (A).

(sealing Accelerator)

In order to improve the interlayer adhesion or the adhesion between the photosensitive resin layer and the substrate, an adhesion promoter may be used in the photosensitive resin composition of the present invention. Examples of the adhesion promoter include: benzimidazole, benzoxazole, benzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole (trade name: Accel M, manufactured by Kayokoku chemical Co., Ltd.), 3-morpholinomethyl-1-phenyl-triazole-2-thione, 5-amino-3-morpholinomethylthiazole-2-thione, 2-mercapto-5-methylthiothiadiazole, triazole, tetrazole, benzotriazole, carboxybenzotriazole, aminobenzotriazole, silane coupling agent, and the like.

(coloring agent)

The photosensitive resin composition of the present invention may contain a colorant. As the colorant to be used, known and commonly used colorants such as red, blue, green, yellow, and white may be used, and any of pigments, dyes, and pigments may be used. Specific examples thereof include: materials with The following color index (C.I.; issued by The Society of Dyers and Colourists) numbers. Among them, it is preferable not to contain halogen from the viewpoint of reducing environmental load and influence on the human body.

Red colorant:

the red colorant includes monoazo-based, disazo-based, azo lake-based, benzimidazolone-based, perylene-based, diketopyrrolopyrrole-based, condensed azo-based, anthraquinone-based, quinacridone-based colorants, and the like, and specific examples thereof include the following colorants.

Mono-azo series: pigment red 1,2, 3,4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151, 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269.

A bisazo system: pigment Red 37, 38, 41.

Monoazo lakes system: pigment Red 48:1, 48:2, 48:3, 48:4, 49:1, 49:2, 50:1, 52:2, 53:1, 53:2, 57:1, 58:4, 63:1, 63:2, 64:1, 68.

Benzimidazolone series: pigment red 171, pigment red 175, pigment red 176, pigment red 185, pigment red 208.

Perylene series: solvent Red 135, solvent Red 179, pigment Red 123, pigment Red 149, pigment Red 166, pigment Red 178, pigment Red 179, pigment Red 190, pigment Red 194, pigment Red 224.

Diketopyrrolopyrroles: pigment red 254, pigment red 255, pigment red 264, pigment red 270, and pigment red 272.

Condensation azo system: pigment red 220, pigment red 144, pigment red 166, pigment red 214, pigment red 220, pigment red 221, and pigment red 242.

Anthraquinone series: pigment red 168, pigment red 177, pigment red 216, solvent red 149, solvent red 150, solvent red 52, solvent red 207.

Quinacridone series: pigment red 122, pigment red 202, pigment red 206, pigment red 207, pigment red 209.

Blue colorant:

examples of the blue colorant include phthalocyanine-based colorants and anthraquinone-based colorants, and the Pigment-based colorants are compounds classified as pigments (pigments), specifically: pigment blue 15, pigment blue 15:1, pigment blue 15:2, pigment blue 15:3, pigment blue 15:4, pigment blue 15:6, pigment blue 16 and pigment blue 60.

As the dye system, solvent blue 35, solvent blue 63, solvent blue 68, solvent blue 70, solvent blue 83, solvent blue 87, solvent blue 94, solvent blue 97, solvent blue 122, solvent blue 136, solvent blue 67, solvent blue 70, and the like can be used. In addition to the above, a metal substituted or unsubstituted phthalocyanine compound may be used.

In addition, blue inorganic pigments can also be suitably used. Examples of blue inorganic pigments include:

ultramarine blue (color Index Name: pigment blue 29), french ultramarine, azure blue, azure, prussian blue (Prussia blue; color Index Name: pigment blue 27);

blue composite oxide pigments such as aluminum-cobalt oxide, aluminum-zinc-cobalt oxide, silicon-cobalt oxide, and silicon-zinc-cobalt oxide;

deep blue (color index name: pigment blue 32), cobalt blue (cobalt aluminate; color index name: pigment blue 28), cobalt stannate (color index name: pigment blue 35), cobalt chromium blue (color index name: pigment blue 36), cobalt-aluminum-silicon oxide, cobalt zinc silicate (color index name: pigment blue 74), cobalt-zinc-silicon oxide (compositional formula: CoO. Al. c. b. c₂O₃·SiO₂Spinel of (d) and the like.

In addition, a pigment containing silicate, such as particles of titanium oxide coated on natural mica, may be used. The chemical formula of natural mica is generally represented by I M_2-3□_1-0T₄O₁₀A₂(I is K, Na, Ca, Ba, Rb, Cs, NH if necessary₄M is Al, Mg, Fe, Li, Ti, Mn, Cr, Zn, V, □ is pore space, T is Si, Al, Fe³⁺Be and B as required, A is OH and F, and Cl, O or S as required).

Green colorant:

the green colorant may be phthalocyanine-based, anthraquinone-based, or perylene-based, and specifically, pigment green 7, pigment green 36, solvent green 3, solvent green 5, solvent green 20, solvent green 28, or the like may be used. In addition to the above, a metal substituted or unsubstituted phthalocyanine compound may be used.

Yellow colorant:

examples of the yellow coloring agent include monoazo-based, disazo-based, condensed azo-based, benzimidazolone-based, isoindolinone-based, and anthraquinone-based coloring agents, and specific examples thereof include the following.

Anthraquinone series: solvent yellow 163, pigment yellow 24, pigment yellow 108, pigment yellow 193, pigment yellow 147, pigment yellow 199, pigment yellow 202.

Isoindolinone series: pigment yellow 110, pigment yellow 109, pigment yellow 139, pigment yellow 179, pigment yellow 185.

Condensation azo system: pigment yellow 93, pigment yellow 94, pigment yellow 95, pigment yellow 128, pigment yellow 155, pigment yellow 166, pigment yellow 180.

Benzimidazolone series: pigment yellow 120, pigment yellow 151, pigment yellow 154, pigment yellow 156, pigment yellow 175, pigment yellow 181.

Mono-azo series: pigment yellow 1,2, 3,4, 5, 6, 9, 10, 12, 61, 62: 1. 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, 183.

A bisazo system: pigment yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198.

Further, a colorant such as violet, orange, brown, black, or the like may be added for adjusting the color tone.

Specific examples thereof include pigment violet 19, 23, 29, 32, 36, 38, 42, solvent violet 13, 36, c.i. pigment orange 1, c.i. pigment orange 5, c.i. pigment orange 13, c.i. pigment orange 14, c.i. pigment orange 16, c.i. pigment orange 17, c.i. pigment orange 24, c.i. pigment orange 34, c.i. pigment orange 36, c.i. pigment orange 38, c.i. pigment orange 40, c.i. pigment orange 43, c.i. pigment orange 46, c.i. pigment orange 49, c.i. pigment orange 51, c.i. pigment orange 61, c.i. pigment orange 63, c.i. pigment orange 64, c.i. pigment orange 71, c.i. pigment orange 73, c.i. pigment brown 23, c.i. pigment brown 25, c.i. pigment black 1, and c.i. pigment black 7.

The amount of the colorant (excluding the white colorant) is not particularly limited, but is preferably 0.01 to 10 parts by mass, particularly preferably 0.1 to 5 parts by mass in terms of solid content, based on 100 parts by mass of the carboxyl group-containing resin (a) having a styrene skeleton.

(Compound having ethylenically unsaturated group (photosensitive monomer))

The photosensitive resin composition of the present invention can use a compound (photosensitive monomer) having 1 or more ethylenically unsaturated groups in the molecule. The compound having 1 or more ethylenically unsaturated groups in the molecule is a compound which is cured by irradiation with active energy rays to make the (a) carboxyl group-containing resin having a styrene skeleton insoluble in an aqueous alkali solution or to contribute to insolubilization of the (a) carboxyl group-containing resin having a styrene skeleton. In particular, when a non-photosensitive substance is used among the carboxyl group-containing resins, it is more preferable from the viewpoint of photocurability.

Examples of compounds that can be used as the photosensitive monomer include: commonly used polyester (meth) acrylates, polyether (meth) acrylates, urethane (meth) acrylates, carbonate (meth) acrylates, epoxy (meth) acrylates, and the like are known. Specifically, there may be mentioned: hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxy tetraethylene glycol, polyethylene glycol, and propylene glycol; acrylamides such as N, N-dimethylacrylamide, N-methylolacrylamide, and N, N-dimethylaminopropylacrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; polyvalent acrylates such as polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol and trishydroxyethyl isocyanurate, ethylene oxide adducts, propylene oxide adducts and epsilon-caprolactone adducts thereof; polyacrylates such as phenoxy acrylate, bisphenol a diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols; polyvalent acrylates of glycidyl ethers such as glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; not limited to the above, there may be mentioned: acrylates and melamine acrylates obtained by directly acrylating a polyol such as a polyether polyol, a polycarbonate diol, a hydroxyl-terminated polybutadiene, or a polyester polyol, or urethane acrylating with a diisocyanate, and at least 1 of the various methacrylates corresponding to the acrylates.

Further, as the photosensitive monomer, an epoxy acrylate resin obtained by reacting acrylic acid with a polyfunctional epoxy resin such as a cresol novolak type epoxy resin, an epoxy urethane acrylate compound obtained by further reacting the hydroxyl group of the epoxy acrylate resin with a half urethane compound formed from a hydroxyl acrylate such as pentaerythritol triacrylate and a diisocyanate such as isophorone diisocyanate, and the like can be used. The epoxy acrylate resin can improve photocurability without reducing finger-touch dryness.

The amount of the compound having 1 or more ethylenically unsaturated groups in the molecule used as the photosensitive monomer is preferably 5 to 100 parts by mass, more preferably 5 to 70 parts by mass in terms of solid content, per 100 parts by mass of the carboxyl group-containing resin having a styrene skeleton (a). When the amount is 5 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 the amount is 100 parts by mass or less, the touch drying property (non-tackiness) is good, and the resolution is also good.

(organic solvent)

Further, the photosensitive resin composition of the present invention may use an organic solvent for synthesizing the carboxyl group-containing resin having a styrene skeleton (a), preparing the composition, or adjusting the viscosity for coating on a substrate or a carrier film.

Examples of such organic solvents include: ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. More specifically, there may be mentioned: ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha. Such organic solvents may be used alone in 1 kind, or may be used in the form of a mixture of 2 or more kinds.

(ultraviolet absorber)

In general, since a polymer material absorbs light and is decomposed and deteriorated, an ultraviolet absorber may be used in the photosensitive resin composition of the present invention in addition to the antioxidant in order to take measures to stabilize the polymer material against ultraviolet rays.

Examples of the ultraviolet absorber include: benzophenone derivatives, benzoate derivatives, benzotriazole derivatives, triazine derivatives, benzothiazole derivatives, cinnamate derivatives, anthranilate derivatives, dibenzoylmethane derivatives, and the like. Specific examples of benzophenone derivatives include: 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2' -dihydroxy-4-methoxybenzophenone, 2, 4-dihydroxybenzophenone and the like. Specific examples of the benzoate derivatives include: 2-ethylhexyl salicylate, phenyl salicylate, p-tert-butylphenyl salicylate, 2, 4-di-tert-butylphenyl 3, 5-di-tert-butyl-4-hydroxybenzoate, hexadecyl 3, 5-di-tert-butyl-4-hydroxybenzoate, and the like. Specific examples of benzotriazole derivatives include: 2- (2 ' -hydroxy-5 ' -tert-butylphenyl) benzotriazole, 2- (2 ' -hydroxy-5 ' -methylphenyl) benzotriazole, 2- (2 ' -hydroxy-3 ' -tert-butyl-5 ' -methylphenyl) -5-chlorobenzotriazole, 2- (2 ' -hydroxy-3 ', 5 ' -di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2 ' -hydroxy-5 ' -methylphenyl) benzotriazole, 2- (2 ' -hydroxy-3 ', 5 ' -di-tert-amylphenyl) benzotriazole and the like. Specific examples of the triazine derivative include: hydroxyphenyl triazine, bis-ethylhexyloxyphenol methoxyphenyl triazine, and the like.

Examples of commercially available ultraviolet absorbers include: TINUVIN PS, TINUVIN 99-2, TINUVIN 109, TINUVIN 384-2, TINUVIN 900, TINUVIN 928, TINUVIN 1130, TINUVIN 400, TINUVIN 405, TINUVIN 460, TINUVIN 479 (see above, manufactured by BASF JAPAN LTD., trade name), and the like.

The ultraviolet absorber may be used alone in 1 kind, or may be used in combination with 2 or more kinds. By using the antioxidant in combination, the cured product obtained from the photosensitive resin composition of the present invention can be stabilized.

(additives)

The photosensitive resin composition of the present invention may further contain a thixotropic agent such as fine powder silica, organobentonite, montmorillonite or hydrotalcite as required. Organobentonite and hydrotalcite are particularly preferred because they are excellent in the stability over time and are therefore preferred as thixotropic agents, and hydrotalcite are excellent in the electrical properties. Further, known and commonly used additives such as a thermal polymerization inhibitor, at least one of a defoaming agent and a leveling agent of a silicone type, a fluorine type, a polymer type, and the like, a rust preventive, and a copper inhibitor of a bisphenol type, a triazine thiol type, and the like may be blended.

The thermal polymerization inhibitor can be used for preventing thermal polymerization or polymerization with time of the polymerizable compound. Examples of the thermal polymerization inhibitor include: 4-methoxyphenol, hydroquinone, alkyl-or aryl-substituted hydroquinone, t-butylcatechol, pyrogallol, 2-hydroxybenzophenone, 4-methoxy-2-hydroxybenzophenone, chloroidene, phenothiazine, tetrachloroquinone, naphthylamine, β -naphthol, 2, 6-di-t-butyl-4-methylphenol, 2' -methylenebis (4-methyl-6-t-butylphenol), pyridine, nitrobenzene, dinitrobenzene, picric acid, 4-toluidine, methylene blue, a reactant of copper with an organic chelating agent, methyl salicylate, and phenothiazine, nitroso compound, a chelate of nitroso compound with Al, and the like.

The photosensitive resin composition of the present invention can be used for forming a pattern layer of a printed wiring board, and can be used as a material for a solder resist layer and an interlayer insulating layer.

The photosensitive resin composition of the present invention can be used in the form of a dry film or in the form of a liquid. When used in a liquid form, the liquid may be 1-liquid type or 2-liquid type or more. Particularly, from the viewpoint of storage stability, the 2-liquid type is preferred. In the case of the 2-liquid type, when the carboxyl group-containing resin (a) having a styrene skeleton used in the invention of the present application is used, (B) a photopolymerization initiator, and (C) an inorganic filler may be blended in the same formulation as the carboxyl group-containing resin (a) having a styrene skeleton, or may be blended in a different formulation. It is particularly preferable to blend (B) the photopolymerization initiator in the same formulation.

The dry film of the present invention is obtained by applying the photosensitive resin composition of the present invention to a film (carrier film) and drying the film, and comprises the carrier film and a layer formed of the photosensitive resin composition and formed on the carrier film.

In the case of dry film formation, the photosensitive resin composition of the present invention is diluted with the organic solvent to a suitable viscosity, and is applied to a support to a uniform thickness by a comma coater (comma coater), a knife coater, a lip coater, a rod coater, a squeeze coater (squeeze coater), a reverse coater (reverse coater), a transfer roll coater, a gravure coater, a spray coater, or the like, and dried at a temperature of 50 to 130 ℃ for 1 to 30 minutes, thereby obtaining a film. The coating film thickness is not particularly limited, and is usually selected appropriately within a range of 10 to 150 μm, preferably 20 to 60 μm, in terms of the film thickness after drying.

As the carrier film, a plastic film can be used, and a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like is preferably used. The thickness of the carrier film is not particularly limited, and is usually appropriately selected within a range of 10 to 150 μm.

After the film is formed on the carrier film, a peelable cover film is preferably further laminated on the surface of the film in order to prevent adhesion of dust and the like 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 as long as the adhesive force between the film and the cover film is smaller than the adhesive force between the film and the support when the cover film is peeled.

For example, the cured coating film of the present invention can be formed by adjusting the viscosity of the cured coating film to a value suitable for a coating method using the organic solvent, applying the cured coating film to a substrate by a method such as dip coating, flow coating, roll coating, bar coating, screen printing, or curtain coating, and volatilizing and drying (temporarily drying) the organic solvent contained in the composition at a temperature of about 60 to 100 ℃. In addition, when the composition is applied onto a carrier film, dried to form a film, and taken up to obtain a dry film, the composition is laminated on a substrate by a laminator or the like so that the photosensitive resin composition layer is in contact with the substrate, and then the carrier film is peeled off, whereby a resin insulation layer can be formed.

Thereafter, the unexposed portion is developed with a dilute alkali aqueous solution (e.g., 0.3 to 3 wt% sodium carbonate aqueous solution) by selectively exposing the resist pattern to an active energy ray through a photomask having a pattern formed thereon by a contact (or non-contact) method or a direct pattern exposure using a laser direct exposure machine, thereby forming a protective pattern. In the case of a composition containing a thermosetting component, for example, the composition is heated to a temperature of about 140 to 180 ℃ and thermally cured, whereby the carboxyl group of the carboxyl group-containing resin (a) having a styrene skeleton reacts with the epoxy resin and the thermosetting component, and a cured coating film having excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties can be formed. Even when the thermosetting component is not contained, the thermal radical polymerization of the ethylenically unsaturated bond remaining in an unreacted state during exposure is carried out by the heat treatment to improve the coating film characteristics, and therefore, the heat treatment (thermosetting) may be carried out according to the purpose and application.

Examples of the substrate include, in addition to a printed wiring board and a flexible printed wiring board on which a circuit is formed in advance, all grades (e.g., FR-4) of copper-clad laminates, polyimide films, PET films, glass substrates, ceramic substrates, and wafer plates, which are made of materials such as a copper-clad laminate for high-frequency circuits using a paper-phenol resin, a paper-epoxy resin, a glass cloth-epoxy resin, a glass-polyimide, a glass cloth/nonwoven fabric-epoxy resin, a glass cloth/paper-epoxy resin, a synthetic fiber-epoxy resin, a fluorine resin/polyethylene/polyphenylene oxide (polyphenylene oxide) cyanate ester, and the like.

The volatilization drying after the application of the photosensitive resin composition of the present invention can be carried out using a hot air circulation type drying oven, an IR oven, a hot plate, a convection oven, or the like (a method of bringing hot air in a dryer into convection contact using a device having a heat source of an air heating system using steam and a method of blowing the hot air to a support through a nozzle).

The coating film obtained by applying the photosensitive resin composition and volatilizing and drying the solvent is exposed (irradiated with active energy rays), whereby the exposed portions (portions irradiated with active energy rays) are cured.

As the exposure machine used for the irradiation with the active energy ray, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like may be mounted and irradiated with ultraviolet rays in the range of 350 to 450nm, and a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser beam using CAD data from a computer) may be used. The laser source of the line drawing machine may be a gas laser or a solid laser as long as the laser having a maximum wavelength in the range of 350 to 410nm is used. The exposure amount for forming an image varies depending on the film thickness, etc., and is usually 20 to 1000mJ/cm²Preferably 20 to 800mJ/cm²Within the range of (1).

As the developing method, a dipping method, a rinsing method, a spraying method, a brush coating method, and the like can be used, and as the developing solution, an alkaline aqueous solution of potassium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, and the like can be used.

Examples

The present invention will be specifically described below by way of examples and comparative examples, but the present invention is not limited to the following examples. In the following, all of the "parts" and "%" are based on mass unless otherwise specified.

[ Synthesis of resin solution 1]

Deionized water was charged into a pressure-resistant vessel equipped with a thermometer, a condenser tube, and a stirrer: 200 parts by mass, sodium sulfate: 0.3 part by mass, dissolution was confirmed.

Then, BPO (benzoyl peroxide) as a polymerization initiator: 5 parts by mass and MSD (alpha-methylstyrene dimer) as a chain transfer agent: 5 parts by mass to a mass of a mixture of MMA (methyl methacrylate): 10.4 parts by mass, n-BA (n-butyl acrylate): 5 parts by mass, MAA (methacrylic acid): 24.6 parts by mass and St (styrene): 60 parts by mass of the resulting monomer mixture was sufficiently dissolved.

Then, a dispersant was added so that the concentration became 300ppm, the mixture was sufficiently stirred, the inside of the reactor was replaced with nitrogen, and the temperature was raised to perform suspension polymerization.

After completion of the polymerization, the resulting suspension was filtered through a sieve having an opening of 30 μm and dried under warm air at 40 ℃ to obtain a granular resin. The thus-obtained granular resin (copolymer resin) was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 1. The acid value of the solid content was 160 mgKOH/g.

[ Synthesis of resin solution 2]

And (3) mixing the BPO: 5 parts by mass were changed to 4.0 parts by mass, and MSD: a granular resin was obtained in the same manner as in the resin solution 1 except that 5 parts by mass was changed to 4.0 parts by mass. The thus-obtained granular resin (copolymer resin) was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 2. The acid value of the solid content was 160 mgKOH/g.

[ Synthesis of resin solution 3]

And (3) mixing the BPO: 5 parts by mass were changed to 1.5 parts by mass, and MSD: a granular resin was obtained in the same manner as in the resin solution 1 except that 5 parts by mass was changed to 1.0 part by mass. The thus-obtained granular resin (copolymer resin) was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 3. The acid value of the solid content was 160 mgKOH/g.

[ Synthesis of resin solution 4]

Deionized water was charged into a pressure-resistant vessel equipped with a thermometer, a condenser tube, and a stirrer: 145 parts by mass, sodium sulfate: 0.3 part by mass, dissolution was confirmed.

Then, tert-butyl peroxy-2-ethylhexanoate (Perbutyl O manufactured by NOF CORPORATION) as a polymerization initiator was: 5 parts by mass and MSD (alpha-methylstyrene dimer) as a chain transfer agent: 4.5 parts by mass to a mass of a mixture of MMA (methyl methacrylate): 45.5 parts by mass, n-BA (n-butyl acrylate): 6 parts by mass, MAA (methacrylic acid): 18.5 parts by mass and St (styrene): 30 parts by mass of the resulting monomer mixture was sufficiently dissolved.

Then, a dispersant was added so that the concentration became 500ppm, the mixture was sufficiently stirred, the inside of the reactor was replaced with nitrogen, and the temperature was raised to perform suspension polymerization.

After completion of the polymerization, the resulting suspension was filtered through a sieve having an opening of 30 μm and dried under warm air at 40 ℃ to obtain a granular resin. The thus-obtained granular resin (copolymer resin) was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 4. The acid value of the solid content was 120 mgKOH/g.

[ Synthesis of resin solution 5 ]

Adding MMA: 45.5 parts by mass was changed to 33.3 parts by mass, and MAA: a granular resin was obtained in the same manner as in the resin solution 4 except that 18.5 parts by mass was changed to 30.7 parts by mass. The thus-obtained granular resin (copolymer resin) was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 5. The acid value of the solid content was 200 mgKOH/g.

[ Synthesis of resin solution 6 ]

Deionized water was put into a removable flask equipped with a thermometer, a condenser, and a stirrer: 145 parts by mass, sodium sulfate: 0.3 part by mass, dissolution was confirmed.

Then, AMBN (2, 2' -azobis (2-methylbutyronitrile)): 0.3 part by mass and n-DM (n-dodecyl mercaptan) as a chain transfer agent: 4 parts by mass to a mass of a mixture of MMA (methyl methacrylate): 55.5 parts by mass, n-BA (n-butyl acrylate): 6 parts by mass, MAA (methacrylic acid): 18.5 parts by mass and St (styrene): 20 parts by mass of the resulting monomer mixture was sufficiently dissolved.

After completion of the polymerization, the obtained suspension was filtered through a sieve having an opening of 30 μm and dried under warm air at 40 ℃ to obtain a granular resin. The thus-obtained granular resin (copolymer resin) was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 6. The acid value of the solid content was 120 mgKOH/g.

[ Synthesis of resin solution 7 ]

In a four-necked flask equipped with a reflux condenser, a thermometer, a glass tube for nitrogen replacement, and a stirrer, MAA (methacrylic acid): 42 parts by mass, MMA (methyl methacrylate): 43 parts by mass of styrene: 35 parts by mass of benzyl acrylate: 35 parts by mass of carbitol acetate: 100 parts by mass of MSD (α -methylstyrene dimer) as a chain transfer agent: 0.5 parts by mass and azobisisobutyronitrile: 4 parts by mass of a copolymer solution (solid content concentration: 50% by mass) was obtained by heating at 75 ℃ for 5 hours under a nitrogen gas flow to cause polymerization reaction. To this solution was added hydroquinone: 0.05 parts by mass of glycidyl methacrylate: 23 parts by mass and dimethylbenzylamine: 2.0 parts by mass, an addition reaction was carried out at 80 ℃ for 24 hours, and then carbitol acetate: 35 parts by mass, a copolymer resin solution having an aromatic ring (resin solution 7) was obtained. The copolymer resin solution (resin solution 7) thus obtained had a solid content concentration of 50% by mass and an acid value of the solid content of 80 mgKOH/g.

[ Synthesis of resin solution 8 ]

A pressure-resistant container equipped with a thermometer, a condenser, and a stirrer was charged with DPM (dipropylene glycol methyl ether): 50 parts by mass, and heating.

Then, tert-butyl peroxyisopropyl monocarbonate (Perbutyl I manufactured by NOF CORPORATION) as a polymerization initiator was: 5 parts by mass to a mass of a mixture of MMA (methyl methacrylate): 10.4 parts by mass, n-BA (n-butyl acrylate): 5 parts by mass, MAA (methacrylic acid): 24.6 parts by mass and St (styrene): the resulting monomer mixture was sufficiently dissolved in 60 parts by mass, and after the temperature of the pressure-resistant vessel was raised to a predetermined temperature, the monomer mixture was dropwise added to the vessel to conduct solution polymerization.

After completion of the polymerization, the mixture was filtered through a sieve having an opening of 5 μm to obtain a resin solution. The resin solution (copolymer resin) thus obtained was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 8. The acid value of the solid content was 160 mgKOH/g.

[ Synthesis of resin solution 9 ]

And (3) mixing the BPO: 5 parts by mass were changed to 1.0 part by mass, and MSD: a granular resin was obtained in the same manner as in the resin solution 1 except that 5 parts by mass was changed to 1.0 part by mass. The resin solution (copolymer resin) thus obtained was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 9. The acid value of the solid content was 160 mgKOH/g.

[ Synthesis of resin solution 10 ]

Adding MMA: 45.5 parts by mass was changed to 48.6 parts by mass, and MAA: a granular resin was obtained in the same manner as in the resin solution 4 except that 18.5 parts by mass was changed to 15.4 parts by mass. The resin solution (copolymer resin) thus obtained was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as the resin solution 10. The acid value of the solid content was 70 mgKOH/g.

[ Synthesis of resin solution 11 ]

Then, AMBN (2, 2' -azobis (2-methylbutyronitrile)): 0.5 parts by mass and MSD (α -methylstyrene dimer) as a chain transfer agent: 3 parts by mass to a mass of a mixture of MMA (methyl methacrylate): 75.5 parts by mass of n-BA (n-butyl acrylate): 6 parts by mass, MAA (methacrylic acid): 18.5 parts by mass of the resulting monomer mixture was sufficiently dissolved.

Then, a dispersant was added so that the concentration became 400ppm, the mixture was sufficiently stirred, the inside of the reactor was replaced with nitrogen, and the temperature was raised to perform suspension polymerization.

After completion of the polymerization, the obtained suspension was filtered through a sieve having an opening of 30 μm and dried under warm air at 40 ℃ to obtain a granular resin. The resin solution (copolymer resin) thus obtained was sufficiently dissolved with an organic solvent DPM (dipropylene glycol methyl ether) so that the solid content concentration became 50 mass%, and the obtained solution was used as a resin solution 11. The acid value of the solid content was 120 mgKOH/g.

[ Synthesis of resin solution 12 ]

In a 2-liter separable flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen inlet tube, diethylene glycol dimethyl ether as a solvent was charged: 900g and tert-butyl peroxy-2-ethylhexanoate (Perbutyl O manufactured by NOF CORPORATION): 21.4g and heated to 90 ℃. After heating, MAA (methacrylic acid): 309.9g, MMA (methyl methacrylate): 116.4g, and caprolactone-modified 2-hydroxyethyl methacrylate (Placcel FM1 manufactured by Daicel Corporation): 109.8g and bis (4-t-butylcyclohexyl) peroxydicarbonate (Peroyl TCP manufactured by NOF CORPORATION): 21.4g, and further aged for 6 hours, thereby obtaining a carboxyl group-containing copolymer resin. The reaction was performed under a nitrogen atmosphere.

Next, 3, 4-epoxycyclohexylmethyl acrylate (CYCLOMER M100 manufactured by Daicel Corporation) was added to the resulting carboxyl group-containing copolymer resin: 363.9g, dimethylbenzylamine as ring-opening catalyst: 3.6g, hydroquinone monomethyl ether as polymerization inhibitor: 1.80g, heated to 100 ℃ and stirred, thereby carrying out a ring-opening addition reaction of the epoxy. After 16 hours, a resin solution 12 containing 50 mass% (non-volatile matter) of a carboxyl group-containing resin having no aromatic ring and a solid content, the resin having an acid value of 108.9mgKOH/g and a weight average molecular weight of 25000, was obtained.

< preparation of photosensitive resin compositions of examples 1 to 12 and comparative examples 1 to 5 >

The components shown in tables 1 and 2 below were compounded in the ratios (parts by mass) shown in the tables, and after premixing with a stirrer, they were kneaded with a 3-roll mill to prepare photosensitive resin compositions.

[ Table 1]

*1: resin solution 1

(styrene skeleton content/acid value/weight average molecular weight 60 (mol%)/160 (mgKOH/g)/10000) (hereinafter, the unit is omitted.)

*2: resin solution 2

(styrene skeleton content/acid value/weight average molecular weight: 60/160/15000)

*3: resin solution 3

(styrene skeleton content/acid value/weight average molecular weight: 60/160/50000)

*4: resin solution 4

(styrene skeleton content/acid value/weight average molecular weight: 30/120/20000)

*5: resin solution 5

(styrene skeleton content/acid value/weight average molecular weight: 30/200/20000)

*6: resin solution 6

(styrene skeleton content/acid value/weight average molecular weight: 20/120/15000)

*7: resin solution 7

(styrene skeleton content/acid value/weight average molecular weight: 20/80/15000)

*8: resin solution 8

(styrene skeleton content/acid value/weight average molecular weight: 60/160/8000)

*9: resin solution 9

(styrene skeleton content/acid value/weight average molecular weight: 60/160/65000)

*10: resin solution 10

(styrene skeleton content/acid value/weight average molecular weight: 30/70/20000)

*11: resin solution 11

(styrene skeleton content/acid value/weight average molecular weight: 0/120/15000)

*12: resin solution 12

(styrene skeleton content/acid value/weight average molecular weight ═ (0/108.9/25000)

*13: bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide (IRGACURE 819, BASF JAPAN LTD. Ltd.)

*14: alpha-Aminoacetophenone photopolymerization initiator (IRGACURE 907 available from BASF JAPAN LTD.)

*15: 2,4, 6-trimethylbenzoyldiphenylphosphine oxide (IRGACURE TPO, manufactured by BASF JAPAN LTD.)

*16: c-1 rutile type titanium oxide (Ti-pure R-931 manufactured by Du Pont Company)

*17: c-2 aluminum hydroxide (H-42M (specific gravity: 2.4) available from Showa Denko K.K.)

*18: c-3 barium sulfate (made by Sakai chemical industry Co., Ltd., B-30)

*19: defoaming agent (KS-66, product of shin-Etsu chemical Co., Ltd.)

*20: heat curing catalyst (Melamine)

*21: heat curing catalyst (DICY (dicyandiamide))

*22: JeR828 (bisphenol A epoxy resin, manufactured by Mitsubishi chemical corporation)

*23: IRGANOX1010 (phenolic antioxidant, manufactured by BASF JAPAN LTD.)

*24: DPHA (dipentaerythritol hexaacrylate, manufactured by Nippon Kagaku Co., Ltd.)

*25: organic solvent (DPM (dipropylene glycol methyl ether))

[ Table 2]

(evaluation method)

< finger touch dryness >

The photosensitive resin compositions of examples and comparative examples were applied to the copper foil substrate having a pattern formed thereon over the entire surface thereof by screen printing, dried in a hot air circulation type drying oven at 80 ℃ for (1)15 minutes and (2)30 minutes, and cooled to room temperature. After a PET film was pressed on the substrate, the adhesion state of the film when the negative film (negative film) was peeled off was evaluated. The results obtained are shown in tables 3 and 4 below.

Very good: and is completely tack-free.

O: it is not sticky.

And (delta): slightly tacky.

X: and was sticky.

< change in reflectance and discoloration >

The photosensitive resin compositions of examples and comparative examples were applied by screen printing to the entire surface of a copper foil substrate having a pattern formed thereon so that the dry film thickness became 20 μm, dried at 80 ℃ for 30 minutes, and cooled to room temperature. After exposing the pattern to an optimum exposure amount using an exposure apparatus equipped with a high-pressure mercury lamp, the pattern was developed with a1 mass% aqueous solution of sodium carbonate at 30 ℃ under a spray pressure of 0.2MPa for 90 seconds to obtain a pattern. The substrate was heated at 150 ℃ for 60 minutes to be cured, and an evaluation substrate having a cured product pattern formed thereon was obtained.

The initial value of the Y value in the XYZ colorimetric system and the initial values of L, a, and b in the L a b colorimetric system were measured at wavelengths of 360 to 740nm using a chromatic aberration meter CR-400 manufactured by Konica Minolta, inc. Then, the evaluation substrate was subjected to light irradiation treatment or heat treatment as described below, and the respective values were measured again by a color difference meter CR-400 manufactured by Konica Minolta, inc. The criteria for determination are as follows. The results obtained are shown in tables 3 and 4 below.

Change in reflectance:

very good: the reduction rate of the Y value is less than 5 percent

O: the reduction rate of Y value is more than 5% and less than 10%

X: the reduction rate of Y value is 10% or more

Color change:

very good: Δ Ε ab < 3

O: Δ Ε ab is 3 or more and less than 5

X: Δ Ε ab is 5 or more

The larger the value of Y, the higher the reflectance. Δ Ε ab is a value obtained by calculating the difference between the initial value and each processed value in the L α a b chromaticity system, and the higher the value, the more noticeable the discoloration. The calculated formula for Δ E ab is shown below.

ΔE*ab＝[(L^*2-L^*1)²+(a^*2-a^*1)²+(b^*2-b^*1)²]^1/2

In the formula, L^*1、a^*1、b^*1Respectively represent initial values of L, a, b, L^*2、a^*2、b^*2Values of L, a, and b after each treatment are shown.

Light irradiation treatment:

the evaluation substrate obtained above was irradiated with 100J/cm light from a UV transfer furnace (output: 150W/cm, metal halide lamp, cold mirror)²The light of (a) causes accelerated degradation thereof.

And (3) heat treatment:

the evaluation substrate thus obtained was reflow-welded 5 times at a heating temperature of 260 ℃ in accordance with the IPC/JETEC J-STD-020 standard. Among them, the 5-time reflow soldering means that the operation of passing through an infrared oven at 260 ℃ for 10 seconds and returning to normal temperature is repeated 5 times.

< sagging Property >

Evaluation of sagging property measurement and evaluation were performed as follows.

1. The photosensitive resin compositions of the examples and comparative examples were dropped on the copper-clad laminate using a syringe.

2. The laminated plate is erected on a substrate support, and a dummy substrate (dummy substrate) is provided in front of the laminated plate so that the laminated plate is not directly blown to the air of the hot air circulation type drying furnace.

3. The laminate was dried in a hot air circulation type drying furnace set at 80 ℃ for 30 minutes in a state where the laminate was raised on a substrate holder.

4. After drying, the length from the center to the lowermost part of the dried photosensitive resin composition was measured.

Very good: the length of the sagging is more than 0cm and less than 2cm

O: the length of the sagging is more than 2cm and less than 4cm

And (delta): the length of the sagging is more than 4cm and less than 6cm

X: the length of the sagging is more than 6cm

The results obtained are shown in tables 3 and 4 below.

< developability >

The photosensitive resin compositions of examples and comparative examples were applied by screen printing to the copper foil substrate having a pattern formed thereon over the entire surface thereof so that the dry film thickness became 20 μm, dried at 80 ℃ for 30 minutes, and cooled to room temperature. The substrate was developed with a1 mass% aqueous solution of sodium carbonate at 30 ℃ under a spray pressure of 0.2MPa, the state of the residue was visually observed, and the development time without residue was measured and evaluated. The results obtained are shown in tables 3 and 4 below.

Very good: within 30 seconds

O: 30 seconds or more and less than 60 seconds

And (delta): 60 seconds or more and less than 120 seconds

X: over 120 seconds

[ Table 3]

[ Table 4]

As shown in the above table, it was confirmed that the compositions of examples containing a carboxyl group-containing resin having a styrene skeleton, a weight average molecular weight of 10000 to 50000, and an acid value of 80 to 200mgKOH/g, a photopolymerization initiator, and an inorganic filler are excellent in both sensitivity and developability, and that the cured product is excellent in the suppression of the decrease in reflectance by light irradiation and heat, and also excellent in the finger-touch drying property, the suppression of discoloration, and the sagging prevention effect, as compared to comparative examples.

Claims

1. A photosensitive resin composition, comprising: (A) a carboxyl group-containing resin having a styrene skeleton, (B) a photopolymerization initiator, (C) titanium oxide, and a carboxyl group-containing resin other than (A),

the carboxyl-containing resin (A) having a styrene skeleton has a weight average molecular weight of 10000 to 25000 and an acid value of 80 to 160mgKOH/g,

the carboxyl group-containing resin (A) having a styrene skeleton has a styrene skeleton content of 10 to 50 mol% in the molecule,

the titanium oxide (C) has a sulfur content of 100ppm or less,

the carboxyl group-containing resin other than (a) includes a carboxyl group-containing resin having no aromatic ring.

2. The photosensitive resin composition according to claim 1, wherein the component (C) is rutile titanium oxide.

3. The photosensitive resin composition according to claim 1, further comprising a thermosetting component.

4. A dry film obtained by applying the photosensitive resin composition according to any one of claims 1 to 3 to a film and drying the applied film.

5. A cured film obtained by curing the photosensitive resin composition according to any one of claims 1 to 3 or a dry film obtained by applying the photosensitive resin composition according to any one of claims 1 to 3 to a film and drying the applied film.

6. A printed wiring board comprising the cured coating film according to claim 5.