JP2009185181A - Photocurable or heat-curable resin composition and cured product thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocurable or heat-curable resin composition which is excellent in storage stability, can be made in one-part type, and gives a cured product excellent in various properties such as adhesion, crack resistance, resistance to the heat of soldering, chemical resistance, electroless gold plating resistance and electric insulation, a dry film of the composition, and a printed wiring board with a solder resist layer formed using those. <P>SOLUTION: The photocurable or heat-curable resin composition comprises (A) a photocurable component containing a carboxy group and an ethylenically unsaturated double bond in a single compound or a combination of two or more compounds, (B) a photopolymerization initiator, and (C) an epoxy resin as a heat-curable component, wherein the epoxy resin (C) is a specific bisphenol type epoxy resin having β-methylepoxy groups at both ends. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photocurable thermosetting resin composition used for the production of printed wiring boards and the like and a dry film thereof, more specifically, excellent in storage stability, and can be composed in a one-pack type, and , Photocuring and thermosetting resin compositions that give cured products with excellent properties such as adhesion, crack resistance, solder heat resistance, chemical resistance, electroless gold plating resistance, and electrical insulation, and dry films thereof About. The present invention also relates to a printed wiring board in which a solder resist layer is formed from a cured product of such a photocurable / thermosetting resin composition or a dry film thereof.

At present, for photo-curable and thermosetting resin compositions used as resists for printed wiring boards, an alkali development type curable composition using a dilute alkaline aqueous solution as a developing solution has become the mainstream in consideration of environmental problems. ing.
Examples of such an alkali-developable photocurable and thermosetting composition include a curable resin obtained by adding a polybasic acid anhydride to a reaction product of a novolak epoxy compound and an unsaturated monocarboxylic acid, A composition comprising a photopolymerization initiator, a photopolymerizable monomer and a polyfunctional epoxy resin having two or more epoxy groups in one molecule (see Patent Document 1), a polyfunctional epoxy compound, and a hydroxyl group-containing substituent Photosensitive prepolymer, photopolymerization initiator, photosensitive (meth) acrylate compound, polyfunctional epoxy resin obtained by reacting a polybasic acid anhydride with a reaction product of a phenol compound and an unsaturated group-containing monocarboxylic acid And a curing catalyst (see Patent Document 2), an aromatic epoxy resin having two glycidyl groups in one molecule and two in one molecule Epihalohydrin is reacted with an alcoholic secondary hydroxyl group obtained by reacting with an aromatic alcohol resin having an enolic hydroxyl group, and an unsaturated group-containing monocarboxylic acid and then an acid anhydride are added to the resulting reaction product. Composition comprising a curable resin, a photopolymerization initiator, a polyfunctional epoxy resin or a photosensitive (meth) acrylate compound (see Patent Documents 3 and 4), a novolak-type phenol resin and an alkylene oxide A carboxyl group-containing photosensitive resin, a photopolymerization initiator, and a polyfunctional epoxy obtained by reacting a reaction product with an unsaturated group-containing monocarboxylic acid and reacting the resulting reaction product with a polybasic acid anhydride. Examples thereof include a resin, or a curable composition containing a photosensitive (meth) acrylate compound (see, for example, Patent Document 5). That.

  As described above, several composition systems have been conventionally proposed as a photocurable / thermosetting resin composition, and are currently used in large quantities in the production of actual printed wiring boards. However, conventional photocurable / thermosetting resin compositions usually contain a polyfunctional epoxy resin having two or more epoxy groups as thermosetting components in order to improve solder heat resistance and the like. Yes. However, since this polyfunctional epoxy resin is highly reactive, the photo-curable / thermosetting resin composition containing it has a short shelf life (thus life) and thickens before application to a circuit board blank. Therefore, it is difficult to make a one-component composition. Therefore, in general, a two-part composition of a curing agent solution mainly composed of a polyfunctional epoxy resin and a main agent solution mainly composed of a photosensitive prepolymer and blended with a curing accelerator is mixed, and these are mixed in use. There was a problem in terms of workability.

Recently, from the viewpoint of processability and smoothness of the cured film surface, it has been required to form a solder resist in a dry film. However, when a photocurable / thermosetting resin composition containing a polyfunctional epoxy resin is in the form of a dry film, there is a problem in storage stability at room temperature, and shelf life (storage life) is shortened. Therefore, at present, most solder resist dry films need to be stored at 0 ° C. or less, and there is a problem that it takes time for transportation and storage.
Japanese Patent Publication No. 1-54390 (Claims) JP-A-11-288091 (Claims) JP-A-5-32746 (Claims) International Publication WO 01 / 53375A1 (Claims) International Publication WO 02/024774 A1 (Claims)

The present invention has been made in view of the problems of the prior art as described above, and its purpose is excellent in storage stability, can be composed in a one-pack type, and has adhesion, crack resistance, and solder heat resistance. An object of the present invention is to provide a photocurable / thermosetting resin composition and a dry film thereof that give a cured product excellent in various properties such as resistance, chemical resistance, electroless gold plating resistance, and electrical insulation.
Furthermore, the objective of this invention is providing the printed wiring board by which a soldering resist layer is formed with the hardened | cured material of this photocurable thermosetting resin composition, or its dry film.

（式中、Ｘは上記式（２）〜（５）のいずれかを表わし、Ｒは水素原子又はハロゲン原子を表わし、ｎは０〜１２の整数である。）
好適な態様においては、前記光硬化性・熱硬化性樹脂組成物は、さらに（Ｄ）ブロックイソシアネートを含有する。 In order to achieve the object, according to the present invention, (A) a photocurable component containing a carboxyl group and an ethylenically unsaturated double bond as a single compound or a combination of two or more compounds, ( In the photocurable / thermosetting resin composition containing B) a photopolymerization initiator and (C) an epoxy resin as a thermosetting component, the epoxy resin (C) is represented by the following general formula (1). A photocurable / thermosetting resin composition is provided which is a bisphenol type epoxy resin having β-methylepoxy groups at both ends.

(In the formula, X represents any of the above formulas (2) to (5), R represents a hydrogen atom or a halogen atom, and n is an integer of 0 to 12.)
In a preferred embodiment, the photocurable / thermosetting resin composition further contains (D) a blocked isocyanate.

According to another aspect of the present invention, a dry film comprising a support and a layer made of the photocurable / thermosetting resin composition formed on the support, or the light A cured product of the curable / thermosetting resin composition is provided.
According to another aspect of the present invention, there is provided a printed wiring board in which a solder resist layer is formed from a cured product or a dry film of the photocurable / thermosetting resin composition.

The photocurable / thermosetting resin composition of the present invention comprises a conventionally used alkali-developable (A) carboxyl group and an ethylenically unsaturated double bond as a single compound or two or more compounds. In the photocurable / thermosetting resin composition containing a photocurable component contained in a combination of (B) a photopolymerization initiator, and (C) an epoxy resin as a thermosetting component, Since a bisphenol type epoxy resin having β-methyl epoxy groups at both ends represented by the general formula (1) is used, it has excellent storage stability and can be composed in a one-pack type. Moreover, since the photocurable thermosetting resin composition of this invention contains the photocurable component (A) and photoinitiator (B) containing a carboxyl group with this epoxy resin, it is photocurable. The coating film can be developed with an alkaline aqueous solution. Therefore, by using the photocurable / thermosetting resin composition of the present invention, characteristics such as electrical insulation and PCT resistance required for resists that can be used for high density printed circuit boards and surface mounting. In addition, a cured film with excellent adhesion to various substrates, solder heat resistance, crack resistance, chemical resistance, and electroless plating resistance can be obtained, and a fine film pattern can be easily formed. Is possible. Moreover, in the photocurable thermosetting resin composition of a suitable aspect, in addition to each above-mentioned component, the flexibility etc. of the cured film obtained are improved by containing (D) block isocyanate further. be able to.
Furthermore, since the photocurable / thermosetting resin composition of the present invention is excellent in storage stability, a photosensitive dry film excellent in room temperature storage stability at 0 ° C. or higher is obtained by using this composition. Can be produced. Therefore, the photocurable / thermosetting resin composition of the present invention is advantageous in terms of workability in the production of printed wiring boards.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has used an alkali development type (A) carboxyl group and an ethylenically unsaturated double bond which are conventionally used as a single compound or 2 In the photocurable / thermosetting resin composition containing a photocurable component containing a combination of two or more kinds of compounds, (B) a photopolymerization initiator, and (C) an epoxy resin as a thermosetting component, When a bisphenol type epoxy resin having β-methyl epoxy groups at both ends represented by the general formula (1) is used as an epoxy resin, a combination of a carboxyl group-containing compound and an epoxy resin that are generally used conventionally It was found that the composition was excellent in storage stability compared to, and could be formed into a one-pack type. That is, since the bisphenol type epoxy resin represented by the general formula (1) has β-methyl epoxy groups at both ends, and a hydrogen atom at the β-position of the epoxy group is substituted with a methyl group, Compared with the epoxy group, the reactivity is low, and even if the carboxyl group of the photocurable component coexists, the reaction hardly occurs at room temperature, and the storage stability is excellent. However, in the post-heating step after exposure and development, it undergoes a polymerization reaction with the carboxyl group of the photocurable component, adhesion to various substrates, solder heat resistance, crack resistance, chemical resistance, electroless gold plating resistance, A cured product excellent in electrical insulation and the like can be obtained. In addition, since the epoxy resin skeleton is a linear bisphenol type, the cured product of the photocurable / thermosetting resin composition containing the skeleton is a cured photocuring / thermosetting resin composition. Compared to products, it forms a flexible coating film without being inferior in heat resistance, has excellent adhesion to a substrate, and has the above-described excellent characteristics required as a resist.

Hereinafter, each component of the photocurable thermosetting resin composition of the present invention will be described.
First, as the photocurable component (A) in the photocurable / thermosetting resin composition of the present invention, conventionally known various carboxyl group-containing photosensitive prepolymers or carboxyl group-containing photosensitive resins (A-1). Can be used alone or in combination of two or more. Further, an alkali-soluble carboxyl group-containing resin (A′-1) and a photopolymerizable monomer (A-2) having an ethylenically unsaturated double bond can be used in combination. In particular, in order to obtain an alkali-developable composition, it is preferable to contain a carboxyl group-containing resin. The carboxyl group-containing photosensitive resin (A-1) having an ethylenically unsaturated double bond, or itself is ethylenic. Any of the carboxyl group-containing resins (A′-1) having no unsaturated double bond can be used, and is not limited to a specific one, but is particularly a compound as listed below (any of oligomers and polymers may be used) Can be suitably used.

  (1) Bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, novolac type epoxy resin, phenol novolac type epoxy resin, cresol novolak Polyfunctional epoxy compound (a) having at least two epoxy groups in the molecule such as epoxy resin, N-glycidyl epoxy resin, preferably novolac epoxy resin such as cresol novolac epoxy resin, phenol novolac epoxy resin, Or an epoxy group of a polyfunctional epoxy resin (a ′) obtained by epoxidizing the hydroxyl group of the polyfunctional epoxy compound (a) with epichlorohydrin and an unsaturated monocarboxylic acid (b) such as (meth) acrylic acid Carbo A saturated or unsaturated polybasic group such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, etc. is further added to the hydroxyl group produced by esterification reaction with a sil group (total esterification or partial esterification, preferably total esterification). A carboxyl group-containing photosensitive resin obtained by reacting the acid anhydride (c).

  (2) Novolac type phenolic resin (d) and alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide, trimethylene oxide, tetrahydrofuran, tetrahydropyran and / or ethylene carbonate, propylene carbonate, butylene carbonate, 2,3-carbonate An unsaturated monocarboxylic acid (b) is reacted with a reaction product with a cyclic carbonate (e) such as propyl methacrylate, and a saturated or unsaturated polybasic acid anhydride (c) is reacted with the obtained reaction product. Obtained carboxyl group-containing photosensitive resin.

  (3) Diisocyanates (f) such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, and carboxyl group-containing dialcohol compounds (g) such as dimethylolpropionic acid and dimethylolbutanoic acid, and Diol compounds (h) such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups. Carboxyl group-containing urethane resin obtained by polyaddition reaction, or glycerin mono (meth) acrylate, trimethylo as the diol compound or part thereof Two hydroxyl groups and one or more ethylenically unsaturated double bonds diol compound (h) used having a carboxyl group-containing photosensitive urethane resin obtained by introducing an unsaturated double bond of propane mono (meth) acrylate.

  (4) Diisocyanate (f), bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol Carboxyl obtained by polyaddition reaction of (meth) acrylate or partial acid anhydride modified product (i) thereof, carboxyl group-containing dialcohol compound (g), and diol compound (h) of bifunctional epoxy resin such as type epoxy resin Group-containing photosensitive urethane resin.

  (5) During the synthesis of the resin of the above (3) or (4), a compound (j) having one hydroxyl group and one or more ethylenically unsaturated double bonds such as hydroxyalkyl (meth) acrylate is added, A carboxyl group-containing photosensitive urethane resin having an unsaturated double bond introduced at the end.

  (6) During the synthesis of the resin of (3) or (4), one isocyanate group and one or more (meth) acryloyl groups are introduced into the molecule such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. A carboxyl group-containing photosensitive urethane resin obtained by adding a compound (k) having a terminal and (meth) acrylated at the terminal.

  (7) At least two oxetane rings in a molecule such as bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene Unsaturated monocarboxylic acid (b) is reacted with polyfunctional oxetane compound (l), and saturated or unsaturated polybasic acid anhydride (c) is reacted with the primary hydroxyl group in the resulting modified oxetane compound. Obtained carboxyl group-containing photosensitive resin.

  (8) Copolymer of unsaturated carboxylic acid (m) such as (meth) acrylic acid and compound (o) having an unsaturated double bond such as styrene, α-methylstyrene, lower alkyl (meth) acrylate and isobutylene In some cases, a compound having an ethylenically unsaturated group such as vinyl group, allyl group or (meth) acryloyl group and a reactive group such as epoxy group or acid chloride, for example, glycidyl (meth) acrylate, is reacted, A carboxyl group-containing photosensitive resin obtained by adding an unsaturated group as a pendant.

  (9) A copolymer of an epoxy group such as glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate and the like (p) having an unsaturated double bond and a compound (o) having an unsaturated double bond And a carboxyl group-containing photosensitive resin obtained by reacting an unsaturated carboxylic acid (m) and reacting the resulting secondary hydroxyl group with a saturated or unsaturated polybasic acid anhydride (c).

  (10) A copolymer of an acid anhydride (q) having an unsaturated double bond such as maleic anhydride or itaconic anhydride and a compound (o) having an unsaturated double bond, hydroxyalkyl (meth) acrylate, etc. A carboxyl group-containing photosensitive resin obtained by reacting the compound (j) having one hydroxyl group and one or more ethylenically unsaturated double bonds.

  (11) A carboxyl group-containing photosensitive resin obtained by introducing an unsaturated double bond into a reaction product of a bisepoxy compound and a bisphenol and subsequently reacting with a saturated or unsaturated polybasic acid anhydride (c). .

  (12) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid (m) and a compound (o) having an unsaturated double bond.

  (13) One molecule such as an alkyl carboxylic acid having 2 to 17 carbon atoms or an aromatic group-containing alkyl carboxylic acid on the epoxy group of the copolymer of the compound (o) having an unsaturated double bond and glycidyl (meth) acrylate An organic acid (r) having one carboxyl group therein and no ethylenically unsaturated bond is reacted, and the resulting secondary hydroxyl group is reacted with a saturated or unsaturated polybasic acid anhydride (c). Obtained carboxyl group-containing resin.

  (14) A carboxyl group-containing polyester resin obtained by reacting a difunctional epoxy resin or a bifunctional oxetane resin with a dicarboxylic acid and adding a saturated or unsaturated polybasic acid anhydride (c) to the primary hydroxyl group produced.

When the compound (including diisocyanate) having an isocyanate group used for the synthesis of the carboxyl group-containing photosensitive urethane resins (3) to (6) is a diisocyanate having no benzene ring, and (1) , (4), (14) polyfunctional and bifunctional epoxy resins having a bisphenol A skeleton, bisphenol F skeleton, biphenyl skeleton, and bixylenol skeleton having a linear structure and hydrogenated compounds thereof In this case, it is preferable in terms of flexibility. In another aspect, the carboxyl group-containing photosensitive urethane resins (3) to (6) have a urethane bond in the main chain, which is preferable for warpage. Moreover, since resin other than said (12)-(14) has a photosensitive group (radical polymerizable unsaturated double bond) in a molecule | numerator, it is preferable at the point of photocurability.
In the present specification, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

  Since the carboxyl group-containing photosensitive resin (A-1) and the carboxyl group-containing resin (A′-1) as described above have a large number of free carboxyl groups in the side chain of the backbone polymer, development with a dilute aqueous alkali solution is performed. Is possible. The acid value of the carboxyl group-containing photosensitive resin (A-1) and the carboxyl group-containing resin (A′-1) is preferably in the range of 40 to 200 mgKOH / g, more preferably 45 to 120 mgKOH / g. It is a range. When the acid value of the carboxyl group-containing photosensitive resin and the carboxyl group-containing resin is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, when the acid value exceeds 200 mgKOH / g, dissolution of the exposed portion by the developer proceeds, which is more than necessary. In some cases, the line is thin, or in some cases, the exposed portion and the unexposed portion are dissolved and separated by the developer without distinction, which makes it difficult to form a normal resist pattern.

  Moreover, although the weight average molecular weight of the said carboxyl group-containing photosensitive resin (A-1) and carboxyl group-containing resin (A'-1) changes with resin frame | skeleton, generally the range of 2,000-150,000 is. Desirably, more preferably in the range of 5,000 to 100,000. If the weight average molecular weight is less than 2,000, the tack-free performance of the coating film may be inferior, the moisture resistance of the coating film after exposure may be poor, the film may be reduced during development, and the resolution may be greatly inferior. On the other hand, when the weight average molecular weight exceeds 150,000, developability may be remarkably deteriorated, and storage stability may be inferior.

  The blending amount of such a carboxyl group-containing photosensitive resin (A-1) and / or carboxyl group-containing resin (A′-1) is desirably in the range of 20 to 70% by mass of the total composition, preferably Is in the range of 30-60% by weight. When the amount is less than the above range, the coating strength is lowered, which is not preferable. On the other hand, when the amount is larger than the above range, the viscosity of the composition is increased or the coating property is lowered, which is not preferable.

  When using only the carboxyl group-containing resin (A′-1), since it does not have an ethylenically unsaturated double bond itself, in order to compose as a photocurable thermosetting resin composition, further It is necessary to use a photopolymerizable monomer (A-2).

  Examples of the photopolymerizable monomer (A-2) include hydroxyl group-containing acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, pentaerythritol triacrylate, and dipentaerythritol pentaacrylate. Water-soluble acrylates such as polyethylene glycol diacrylate and polypropylene glycol diacrylate; polyfunctional polyester acrylates of polyhydric alcohols such as trimethylolpropane tri (meth) acrylate, pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate; Ethylene of polyfunctional alcohols such as methylolpropane and hydrogenated bisphenol A or polyphenols such as bisphenol A and biphenol Oxide adducts and / or propylene oxide adducts; polyfunctional or monofunctional polyurethane acrylates that are isocyanate modified products of the above hydroxyl group-containing acrylates; bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, or phenol novolac epoxy resins (Meth) acrylic acid adducts: caprolactone-modified ditrimethylolpropane tetraacrylate, ε-caprolaclone-modified dipentaerythritol acrylate, caprolactone-modified hydroxypivalic acid neopentyl glycol ester diacrylate, and other caprolactone-modified acrylates And photosensitive (meth) acrylates such as methacrylates corresponding to the above acrylates A compound is mentioned, These can be used individually or in combination of 2 or more types. Among these, a polyfunctional (meth) acrylate compound having two or more (meth) acryloyl groups in one molecule is preferable. The purpose of using these photosensitive (meth) acrylate compounds is to have photocurability in the composition. Photosensitive (meth) acrylate compounds that are liquid at room temperature are used for the purpose of imparting photocurability to the composition, as well as for adjusting the composition to a viscosity suitable for various coating methods, and for assisting solubility in alkaline aqueous solutions. Also fulfills. However, if a large amount of liquid photosensitive (meth) acrylate compound is used at room temperature, the dryness of the coating film cannot be obtained, and the characteristics of the coating film tend to deteriorate. It is not preferable. The blending amount of the photosensitive (meth) acrylate compound is preferably 100 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing resin (A′-1). Moreover, a photosensitive (meth) acrylate compound can be mix | blended with the said carboxyl group-containing photosensitive resin (A-1) in order to raise photoreactivity. In this case, the compounding amount of the photosensitive (meth) acrylate compound is 100 parts by mass of the carboxyl group-containing photosensitive resin (A-1) and / or carboxyl group-containing resin (A′-1) (total amount or single use). In some cases, 100 parts by mass or less is preferable with respect to a single amount, the same applies hereinafter.

  Examples of the photopolymerization initiator (B) include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2, Acetophenones such as 2-diethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2- Aminoacetophenones such as dimethylamino-1- (4-morpholinophenyl) -butan-1-one, N, N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1- Chloro Anthraquinones such as nthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzoylper Organic peroxides such as oxide and cumene peroxide; 2,4,5-triarylimidazole dimer; Riboflavin tetrabutyrate; Thiols such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole Compound; Organic halogen compounds such as 2,4,6-tris-s-triazine, 2,2,2-tribromoethanol, tribromomethylphenylsulfone; benzophenone, 4,4'-bisdie Benzophenones or xanthones such as Le aminobenzophenone; and 2,4,6-trimethylbenzoyl diphenylphosphine oxide. These known and commonly used photopolymerization initiators can be used alone or as a mixture of two or more thereof. Further, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4- Photoinitiator aids such as tertiary amines such as dimethylaminobenzoate, triethylamine, triethanolamine can be added. A titanocene compound such as CGI-784 (manufactured by Ciba Specialty Chemicals Co., Ltd.) having absorption in the visible light region can also be added to promote the photoreaction. Particularly preferred photopolymerization initiators are 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butan-1-one and the like, but is not particularly limited thereto, and absorbs light in the ultraviolet light or visible light region, such as (meth) acryloyl group As long as the unsaturated group is radically polymerized, it is not limited to a photopolymerization initiator and a photoinitiator aid, and can be used alone or in combination. And the usage-amount is the ratio of 0.5-25 mass parts with respect to 100 mass parts of said carboxyl group-containing photosensitive resin (A-1) and / or carboxyl group-containing resin (A'-1).

  The bisphenol type epoxy resin (C) having β-methyl epoxy groups at both ends represented by the general formula (1) is an aprotic polarity such as dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide or the like. Solvent, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, quaternary ammonium salts in known solvents such as aromatic hydrocarbons such as toluene and xylene or without solvent In the presence of a basic catalyst such as a quaternary basic salt compound such as β-methyl epichlorohydrin, β-methyl epibromohydrin, β-methyl epiiodohydrin, etc. -It can be obtained by reacting methyl epihalohydrin, but its production method is not particularly limited, The law is fine. Examples of bisphenols include bisphenol A, hydrogenated bisphenol A, brominated bisphenol A, bisphenol F, and bisphenol S, and these can be used alone or in combination of two or more. Although the reaction proceeds even at room temperature, it is preferable to warm the reaction mixture in order to increase the reaction rate.

  The blending ratio of the bisphenol type epoxy resin (C) having β-methyl epoxy groups at both ends represented by the general formula (1) is the carboxyl group-containing photosensitive resin (A-1) and / or carboxyl group-containing resin. The β-methylepoxy group is preferably in the range of 0.8 to 1.5 equivalents relative to 1 equivalent of the carboxyl group of (A′-1). When the blending ratio of the bisphenol-type epoxy resin (C) is less than 0.8 equivalent, a carboxyl group remains in the cured film, which is not preferable because heat resistance, alkali resistance, electrical insulation, and the like are lowered. On the other hand, when it exceeds 1.5 equivalents, storage stability and the like are lowered, which is not preferable.

  The photocurable / thermosetting resin composition of the present invention is combined with a bisphenol-type epoxy resin (C) having β-methyl epoxy groups at both ends represented by the general formula (1) to form a blocked isocyanate (D). Can be contained. The bifunctional blocked isocyanate is a compound obtained by blocking the diisocyanate as described above with a blocking agent such as phenol, cresol, or ε-caprolactam. When using such a blocked isocyanate, the β-methyl epoxy group-containing bisphenol type epoxy resin (C) represented by the general formula (1) is 0.25 to 1.0 equivalent and the blocked isocyanate is 1 to 1.5 equivalent. It is preferable to use together in proportions. By using a blocked isocyanate in combination with the β-methylepoxy group-containing bisphenol type epoxy resin (C) represented by the general formula (1), the carboxyl group-containing photosensitive resin ( A block isocyanate reacts with the hydroxyl group produced by the reaction between the carboxyl group of the A-1) and / or carboxyl group-containing resin (A′-1) and the β-methylepoxy group, and a urethane bond is introduced into the resin. The flexibility of the resulting cured film can be improved.

  The photocurable / thermosetting resin composition of the present invention can contain a thermosetting catalyst. Examples of such thermosetting catalysts include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. Imidazole derivatives such as 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N -Amine compounds such as dimethylbenzylamine and 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd., U-CAT (registered by San Apro) Trademarks) 3503N, U-CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof), and the like. It is not particularly limited to these, as long as it is a thermosetting catalyst for an epoxy resin or an oxetane compound, or a catalyst that promotes the reaction between an epoxy group and / or an oxetanyl group and a carboxyl group. May be used. Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine and isocyanuric acid adducts and 2,4-diamino-6-methacryloyloxyethyl-S-triazine and isocyanuric acid adducts can also be used. A compound that also functions in combination with the thermosetting catalyst.

  The compounding amount of these thermosetting catalysts is sufficient in the usual quantitative ratio. For example, 100 parts by mass of the bisphenol type epoxy resin (C) having β-methyl epoxy groups at both ends represented by the general formula (1). On the other hand, it is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass.

Further, the photocurable / thermosetting resin composition used in the present invention is an organic solvent for dissolving the photocurable component and the thermosetting component and adjusting the composition to a viscosity suitable for the coating method. Can be blended.
Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether , Glycol ethers such as diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate , Ethylene glycol monobutyl ether Acetates such as cetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol, propylene glycol; octane, decane, etc. Aliphatic hydrocarbons; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. These organic solvents can be used alone or as a mixture of two or more. The compounding quantity of the organic solvent can be made into arbitrary quantity according to a use etc.

  The photocurable / thermosetting resin composition used in the present invention may further include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, if necessary. In addition, known inorganic fillers such as calcium carbonate, aluminum oxide, aluminum hydroxide and mica can be used alone or in combination of two or more. These are used for the purpose of suppressing curing shrinkage of the coating film and improving properties such as adhesion and hardness. The compounding quantity of an inorganic filler is 300 mass parts or less with respect to 100 mass parts of said carboxyl group-containing photosensitive resin (A-1) and / or carboxyl group-containing resin (A'-1), Preferably it is 30-200 mass. The proportion of parts is appropriate.

  A colorant can be further blended in the photocurable / thermosetting resin composition used in the present invention, if necessary. As the colorant, conventionally known colorants such as red, blue, green, yellow, etc., such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black are used. Any of pigments, dyes, and pigments may be used. However, it is preferable not to contain a halogen from the viewpoint of reducing the environmental burden and affecting the human body.

  Further, the photocurable / thermosetting resin composition used in the present invention may further include, as necessary, known and commonly used thermal polymerization inhibitors such as phenothiazine, hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, and fine powder. Known and commonly used thickeners such as silica, organic bentonite and montmorillonite, defoamers and / or leveling agents such as silicone, fluorine and polymer, silane coupling agents such as imidazole, thiazole and triazole, Known and commonly used additives such as a flame retardant such as a phosphorus flame retardant and an antimony flame retardant, an antioxidant and a rust inhibitor can be blended.

  When forming a dry film, the photocurable / thermosetting resin composition of the present invention is diluted with the above organic solvent to adjust to an appropriate viscosity, and then a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse A film can be obtained by applying a uniform thickness on a carrier film (support) with a coater, transfer roll coater, gravure coater, spray coater, etc., and usually drying at a temperature of 50 to 130 ° C. for 1 to 30 minutes. it can. Although there is no restriction | limiting in particular about a coating film thickness, Generally, it is 10-150 micrometers by the film thickness after drying, Preferably it selects suitably in the range of 20-60 micrometers. Drying is performed using a hot air circulation drying furnace, IR furnace, hot plate, convection oven, etc. (using a heat source with an air heating method using steam, bringing the hot air in the dryer into countercurrent contact, or from the nozzle to the support. Spraying method).

As the carrier film, a plastic film is used, and a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, or a polystyrene film is preferably used. Although there is no restriction | limiting in particular about the thickness of a carrier film, Generally, it selects suitably in the range of 10-150 micrometers.
After the film is formed on the carrier film, it is desirable to further laminate a peelable cover film (protective film) on the surface of the film for the purpose of preventing dust from adhering to the surface of the film.

  As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper or the like can be used, and when the cover film is peeled off, the adhesive strength between the film and the carrier film is exceeded. What is necessary is just to have a smaller adhesive force between the membrane and the cover film.

  When the liquid photocurable / thermosetting resin composition of the present invention having the above composition is in a liquid state, it is adjusted to a viscosity suitable for the coating method with the organic solvent as necessary, and then on the substrate. The dip coating method, flow coating method, roll coating method, bar coater method, screen printing method, curtain coating method and the like are applied, and the organic solvent contained in the composition is volatilized at a temperature of about 60 to 100 ° C. A tack-free coating film can be formed by drying (temporary drying). Moreover, in the case of the said dry film form, it bonds together on a base material using a vacuum laminator etc. (It bonds so that the said photocurable thermosetting resin composition layer and a base material may contact). In the case of a dry film provided with a peelable cover film on the photocurable / thermosetting resin composition layer of the above film, after the cover film (or carrier film) is peeled off, the photocurable / thermosetting It bonds together using a vacuum laminator etc. so that a conductive resin composition layer and a base material may contact.

  After that, for the obtained coating film (photocurable / thermosetting resin composition layer) (when the above dry film is used, after laminating on the substrate, the film (carrier film or cover film) is not peeled off) ), Exposure (irradiation with active energy rays) is performed. The exposure may be either a contact type (or non-contact type) method of selectively exposing with an active energy ray through a photomask on which a pattern has been formed, or a method of direct pattern exposure using a laser direct exposure machine. By this exposure, the exposed portion (portion irradiated with active energy rays) of the coating film is cured. Next, the unexposed portion is developed with a dilute alkaline aqueous solution (for example, 0.3 to 3% sodium carbonate aqueous solution) to form a resist pattern (when the above dry film is used, after exposure, a film (carrier film or cover film) ), And unexposed areas are developed). Thereafter, for example, by heating to a temperature of about 120 to 180 ° C. and thermosetting, or by heat curing after irradiation with active energy rays or final curing (main curing) by irradiation with active energy rays after heat curing, The carboxyl group of the carboxyl group-containing photosensitive resin (A-1) or / and the carboxyl group-containing resin (A′-1), and β-methyl of the bisphenol type epoxy resin (C) represented by the general formula (1) An epoxy group reacts to form a cured film having excellent properties such as adhesion, solder heat resistance, chemical resistance, moisture absorption resistance, electroless gold plating resistance, and electrical insulation.

  Examples of the substrate include a printed wiring board on which a circuit is formed in advance, in particular, a flexible printed wiring board, paper-phenol resin, paper-epoxy resin, glass cloth-epoxy resin, glass-polyimide, glass cloth / non-woven cloth-epoxy. Resin, glass cloth / paper-epoxy resin, synthetic fiber-epoxy resin, copper-clad laminates of all grades (FR-4 etc.) using polyimide, polyethylene, PPO, cyanate ester, etc., polyimide film PET film, glass substrate, ceramic substrate, wafer plate and the like can be used.

As an exposure machine used for the active energy ray irradiation, a high-pressure mercury lamp lamp, an ultra-high pressure mercury lamp lamp, a metal halide lamp, a mercury short arc lamp, and the like may be used as long as the apparatus irradiates ultraviolet rays in a range of 350 to 450 nm. Furthermore, a direct drawing apparatus (for example, a laser direct imaging apparatus that directly draws an image with a laser using CAD data from a computer) can also be used. As the laser light source of the direct drawing machine, either a gas laser or a solid laser may be used as long as laser light having a maximum wavelength in the range of 350 to 410 nm is used. The amount of exposure for image formation varies depending on the film thickness and the like, but is generally 20 to 1000 mJ / cm ² , preferably 100 to 900 mJ / cm ² .

  The developing method can be a dipping method, a shower method, a spray method, a brush method or the like, and as a developer, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, Alkaline aqueous solutions such as ammonia and amines can be used.

  EXAMPLES Hereinafter, although an Example etc. are shown and this invention is demonstrated more concretely, this invention is not limited to these Examples. In the following description, “parts” and “%” are all based on mass unless otherwise specified.

Synthesis example 1
In a reaction vessel equipped with a stirrer, a thermometer, and a condenser, polycarbonate diol derived from 1,5-pentanediol and 1,6-hexanediol (Asahi Kasei Chemicals Co., Ltd., T-5650J, average molecular weight 800) 280 Parts (3 moles), dimethylolpropionic acid 70 parts (4.5 moles) as a dihydroxyl compound having a carboxyl group, isophorone diisocyanate 220 parts (8.5 moles) as a polyisocyanate, and 2-hydroxyethyl acrylate as a monohydroxyl compound 40 parts (2.6 mol) were added. The mixture was heated to 60 ° C. while stirring and stopped. When the temperature in the reaction vessel started to decrease, the mixture was heated again and stirred at 80 ° C., and the absorption spectrum of the isocyanate group (2280 cm ⁻¹ ) was observed in the infrared absorption spectrum. The reaction was terminated after confirming disappearance. Dipropylene glycol monomethyl ether acetate was added so that the solid content was 50% by mass to obtain a viscous liquid polyurethane containing a diluent. The solid content acid value of the obtained photosensitive polyurethane containing a carboxyl group was 48 mgKOH / g.

Synthesis example 2
2200 parts of cresol / novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-104S, softening point 92 ° C., epoxy equivalent 220), 134 parts of dimethylolpropionic acid, 648.5 parts of acrylic acid, 4.6 of methylhydroquinone Part, 1131 parts of carbitol acetate and 484.9 parts of solvent naphtha were heated to 90 ° C. and stirred to dissolve the reaction mixture. Next, the reaction liquid was cooled to 60 ° C., charged with 13.8 parts of triphenylphosphine, heated to 100 ° C., and reacted for about 32 hours to obtain a reaction product having an acid value of 0.5 mgKOH / g. Next, 364.7 parts of tetrahydrophthalic anhydride, 137.5 parts of carbitol acetate, and 58.8 parts of solvent naphtha were added to this, heated to 95 ° C., reacted for about 6 hours, cooled, and solid acid value A carboxyl group-containing photosensitive resin having 40 mg KOH / g and a nonvolatile content of 65% was obtained.

Synthesis example 3
380 parts of bisphenol F type epoxy resin (epoxy equivalent 950 g / eq, softening point 85 ° C., average polymerization degree n = 6.2) and 925 parts of epichlorohydrin were dissolved in 462.5 parts of dimethyl sulfoxide, and then stirred. 60.9 parts (1.5 mol) of sodium hydroxide having a purity of 98.5% at 70 ° C. was added over 100 minutes. After the addition, the reaction was further carried out at 70 ° C. for 3 hours. After completion of the reaction, 250 parts of water was added and washed with water. After the oil / water separation, most of the dimethyl sulfoxide and excess unreacted epichlorohydrin were recovered from the oil layer under reduced pressure, and the reaction product containing the remaining replication salt and dimethyl sulfoxide was dissolved in 750 parts of methyl isobutyl ketone, and further 30% NaOH. 10 parts of an aqueous solution was added and reacted at 70 ° C. for 1 hour. After completion of the reaction, washing was performed twice with 200 parts of water. After separation of oil and water, til isobutyl ketone was recovered by distillation from the oil layer to obtain an epoxy resin (a) having an epoxy equivalent of 310 g / eq and a softening point of 69 ° C. When the epoxy resin (a) obtained was calculated from the epoxy equivalent, about 5 of the 6.2 alcoholic hydroxyl groups in the starting material bisphenol F type epoxy resin were epoxidized. 310 parts of this epoxy resin (a) and 282 parts of carbitol acetate were charged into a four-necked flask equipped with a stirrer and a reflux condenser, and heated and stirred at 90 ° C. to dissolve. The obtained solution is once cooled to 60 ° C., 72 parts of acrylic acid, 0.5 part of methylhydroquinone and 2 parts of triphenylphosphine are added, heated to 100 ° C., reacted for about 60 hours, and the acid value is 0.2 mg KOH. / G of reaction product was obtained. To this, 140 parts of tetrahydrophthalic anhydride was added, heated to 90 ° C., and reacted until the solid content acid value reached 100 mgKOH / g to obtain a solution containing 65% carboxyl group-containing photosensitive resin.

Synthesis example 4
A novolac-type cresol resin (manufactured by Showa Polymer Co., Ltd., trade name “Shonol CRG951”, OH equivalent: 119.4) 119. 4 parts, 1.19 parts of potassium hydroxide and 119.4 parts of toluene were charged, the system was purged with nitrogen while stirring, and the temperature was raised. Next, 63.8 parts of propylene oxide was gradually added dropwise and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Thereafter, the reaction solution was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The nonvolatile content was 62.1% and the hydroxyl value was 182.2 g / eq. A novolak-type cresol resin propylene oxide reaction solution was obtained. This was an average of 1.08 moles of alkylene oxide added per equivalent of phenolic hydroxyl group. 293.0 parts of an alkylene oxide reaction solution of the obtained novolak-type cresol resin, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 part of methylhydroquinone and 252.9 parts of toluene were mixed with a stirrer and a temperature. A reactor equipped with a meter and an air blowing tube was charged, air was blown at a rate of 10 ml / min, and the reaction was carried out at 110 ° C. for 12 hours while stirring. 12.6 parts of water was distilled from the water produced by the reaction as an azeotrope with toluene. Thereafter, the reaction solution was cooled to room temperature, neutralized with 35.35 parts of a 15% aqueous sodium hydroxide solution, and then washed with water. Thereafter, toluene was distilled off while substituting 118.1 parts of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak acrylate resin solution. Next, 332.5 parts of the obtained novolak acrylate resin solution and 1.22 parts of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was supplied at a rate of 10 ml / min. While blowing and stirring, 60.8 parts of tetrahydrophthalic anhydride was gradually added, reacted at 95 to 101 ° C. for 6 hours, cooled and taken out. The carboxyl group-containing photosensitive resin thus obtained had a nonvolatile content of 70.6% and a solid content acid value of 87.7 mgKOH / g.

Examples 1 to 5 and Comparative Examples 1 and 2
The compounding components shown in Table 1 using the varnishes obtained in Synthesis Examples 1 to 4 were kneaded with a three-roll mill to obtain a photocurable / thermosetting resin composition.

Preparation of evaluation dry film:
Each photocurable / thermosetting resin composition obtained was applied to a 16 μm thick PET film as a support film so that the film thickness was about 40 μm after drying with a film applicator. Was dried at 80 ° C. for 30 minutes to form a composition layer. Then, the 25-micrometer-thick polypropylene film with an embossing which is a protective film was bonded together on the composition layer surface with a 60 degreeC hot roll, and the dry film was produced.
Using each of the obtained dry films, developability (confirm development margin from lamination to development), solder heat resistance, electroless gold plating resistance, storage stability, flexibility by the following test methods A test was conducted. The results are shown in Table 2.

Developability (confirmation of development margin from lamination to development):
In order to confirm the development margin in the substrate preparation process up to the development process, the protective film was peeled off from the dry film obtained as described above, and acid cleaning, water washing and drying were performed so that the composition layer surface was in contact with the substrate surface. It piled up on the copper pasting laminated substrate. Then, it laminated with the vacuum laminator (MVLP-500 by Meiki Seisakusho) with the PET film surface as the upper surface. The obtained test substrate is thermally accelerated by placing it in a 90 ° C hot air forward ring drying furnace for 30 minutes, and after peeling off the PET film, it is sprayed with a 1% sodium carbonate aqueous solution at a liquid temperature of 30 ° C. Spray development was performed at a pressure of 0.2 MPa for 120 seconds, and the presence or absence of a residue was visually evaluated.
○: Almost no development residue remains.
Δ: Some development residue remains.
X: Development residue remains.

Solder heat resistance:
The surface of the copper foil of a printed board having a copper foil thickness of 18 μm was buffed, dried after washing with water. On the other hand, the protective film was peeled off from the dry film obtained as described above, and was overlaid on the printed circuit board so that the composition surface layer was in contact with the substrate surface. Then, it laminated with the vacuum laminator (MVLP-500 by Meiki Seisakusho) with the PET film surface as the upper surface. Next, the laminated substrate was exposed using an ultraviolet exposure device (HMW-680GW manufactured by Oak Manufacturing Co., Ltd.), and spray development was performed with a 1% sodium carbonate aqueous solution at a spray pressure of 0.2 MPa for 120 seconds. Thereafter, a thermosetting reaction was performed in a hot air forward ring drying oven at 150 ° C. The exposure amount was set to an exposure amount at which a 5-step residual sensitivity was obtained with a step tablet (No. 2 21 steps, manufactured by Kodak Company). A rosin-based flux was applied to each of the obtained test substrates, immersed in a solder bath at 260 ° C. for 10 seconds, and then a coating state after a peeling test using a cellophane adhesive tape was evaluated.
○: No change in coating after peeling.
X: Detachment after peeling.

Electroless gold plating resistance:
Using a commercially available electroless nickel plating bath and electroless gold plating bath on a test substrate that has been subjected to thermosetting under the same method and conditions as the test substrate used in the solder heat resistance test, nickel 0.5 μm, gold 0 Then, plating was performed under a condition of 0.03 μm, and after the plating treatment, the film was sufficiently dried at 150 ° C. for 10 minutes, and then the presence or absence of peeling of the cured coating film or the presence or absence of plating penetration was evaluated by tape peeling.
○: No peeling at all.
X: The cured coating film has peeling.

Storage stability:
The ink was stored in a constant temperature and humidity chamber at 50 ° C. for 5 days in the state of the ink before being formed into a dry film, and the change in viscosity before and after storage was measured to obtain the thickening rate. The viscosity was measured with a cone plate viscometer at an ink temperature of 25 ° C. The thickening rate was calculated by thickening rate (%) = viscosity after storage ÷ viscosity before storage × 100.
○: Thickening rate is less than 200%.
X: Thickening rate exceeds 200% or gelled.

Flexible:
Using a dry film prepared as described above on one side of a 25 μm-thick polyimide film (Kapton 100EN manufactured by Toray DuPont), lamination, exposure, development, and heat under the same method and conditions as in the solder heat resistance test It went to hardening. The obtained test substrate was cut into 8 cm × 1 cm strips, bent 180 ° with the composition layer surface facing outward, and the presence or absence of cracks was confirmed using a 50 × scope. Thereafter, the second time was folded alternately with the composition layer surface on the inner side and the third time on the outer side, and the number of folding times at which cracks were generated was evaluated.
(Double-circle): Bending 5 times and there is no crack generation.
○: No bending due to bending.
X: Cracks are generated by bending it.

上記表２に示されるように、エポキシ樹脂として通常用いられるビスフェノールＡ型エポキシ樹脂を用いた比較例１、２の場合、保存安定性に劣っていた。これに対し、β−メチルエポキシ基を含有するビスフェノールＡ型エポキシ樹脂を用いた本発明の実施例１〜５の場合、保存安定性に優れていた。尚、カルボキシル基含有感光性樹脂として合成例１で調製したカルボキシル基含有感光性ウレタン樹脂を用いた実施例１、４、５の場合、可撓性に優れているため、フレキシブル配線板用に好適である。

As shown in Table 2 above, in the case of Comparative Examples 1 and 2 using a bisphenol A type epoxy resin usually used as an epoxy resin, the storage stability was poor. On the other hand, in the case of Examples 1-5 of the present invention using a bisphenol A type epoxy resin containing a β-methyl epoxy group, the storage stability was excellent. In Examples 1, 4, and 5 where the carboxyl group-containing photosensitive urethane resin prepared in Synthesis Example 1 was used as the carboxyl group-containing photosensitive resin, because of excellent flexibility, it is suitable for a flexible wiring board. It is.

Examples 6 to 9 and Comparative Examples 3 and 4
The compounding components shown in Table 3 using the varnishes obtained in Synthesis Examples 1 to 4 were kneaded with a three-roll mill to obtain a photocurable / thermosetting resin composition.

Production of evaluation board:
Each photocurable / thermosetting composition obtained was printed on a printed circuit board using a 120 mesh polyester screen film by a screen printing method to a film thickness of about 20 μm after drying. For 30 minutes at 80 ° C. Next, a negative film for obtaining a predetermined pattern is adhered to the coating film, exposed using an ultraviolet exposure device (HMW-680GW manufactured by Oak Manufacturing Co., Ltd.), and spray-developed with a 1% aqueous sodium carbonate solution. After that, a thermosetting reaction was performed in a hot air forward ring drying oven at 150 ° C. The exposure amount was set to an exposure amount at which a 5-step residual sensitivity was obtained with a step tablet (No. 2 21 steps, manufactured by Kodak Company). Using the obtained test substrate, each test of solder heat resistance, electroless gold plating resistance, and flexibility was performed in the same manner as described above. Furthermore, the dry management width was also evaluated as follows. The results are shown in Table 4.

Drying control width:
The photocurable / thermosetting resin compositions of Examples 6 to 9 and Comparative Examples 3 and 4 were applied on the entire surface of the printed circuit board by screen printing, and the drying time was changed at 90 ° C. at intervals of 10 minutes each. A substrate was prepared. Thereafter, development was performed with a 1% Na ₂ CO ₃ aqueous solution at a spray pressure of 0.2 MPa for 120 seconds, and the drying control width (the longest drying time that can be developed) was examined.

上記表４に示されるように、エポキシ樹脂として通常用いられるビスフェノールＡ型エポキシ樹脂を用いた比較例３、４の場合、保存安定性に劣るため乾燥管理幅が短かった。これに対し、β−メチルエポキシ基を含有するビスフェノールＡ型エポキシ樹脂を用いた本発明の実施例６〜９の場合、保存安定性に優れているため長時間の乾燥管理幅が得られた。尚、カルボキシル基含有感光性樹脂として合成例１で調製したカルボキシル基含有感光性ウレタン樹脂を用いた実施例６、９の場合、可撓性に優れているため、フレキシブル配線板用に好適である。

As shown in Table 4 above, in Comparative Examples 3 and 4 using a bisphenol A type epoxy resin that is usually used as an epoxy resin, the drying control range was short because of poor storage stability. On the other hand, in Examples 6 to 9 of the present invention using a bisphenol A type epoxy resin containing a β-methylepoxy group, a long drying control width was obtained because of excellent storage stability. In addition, in Examples 6 and 9 using the carboxyl group-containing photosensitive urethane resin prepared in Synthesis Example 1 as the carboxyl group-containing photosensitive resin, since it is excellent in flexibility, it is suitable for a flexible wiring board. .

Claims (5)

(A) a photocurable component containing a carboxyl group and an ethylenically unsaturated double bond as a single compound or a combination of two or more compounds, (B) a photopolymerization initiator, and (C) thermosetting. In the photocurable thermosetting resin composition containing an epoxy resin as a component, the epoxy resin (C) is a bisphenol type epoxy having β-methyl epoxy groups at both ends represented by the following general formula (1) A photocurable / thermosetting resin composition, which is a resin.

(In the formula, X represents any of the above formulas (2) to (5), R represents a hydrogen atom or a halogen atom, and n is an integer of 0 to 12.)   Furthermore, (D) blocked isocyanate is contained, The photocurable thermosetting resin composition of Claim 1 characterized by the above-mentioned.   A dry film comprising: a support; and a layer made of the photocurable thermosetting resin composition according to claim 1 or 2 formed on the support.   Hardened | cured material of the photocurable thermosetting resin composition of the said Claim 1 or 2.   The printed wiring board by which a soldering resist layer is formed with the hardened | cured material of the photocurable thermosetting resin composition of the said Claim 1 or 2, or the dry film of Claim 3.