JP2003057821A - Photosensitive resin and photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin and a photosensitive resin composition excellent in stability after the preparation of the composition, thermal stability in a solvent volatilizing step, suitability to set to touch after the volatilization of the solvent and developability in a dilute aqueous alkali solution and giving a finally cured coating excellent in flexibility, heat resistance, resistance to the heat of soldering, adhesion, water resistance, chemical resistance, etc. SOLUTION: The photosensitive resin is obtained by reacting a copolymer (I) obtained by copolymerizing one or more unsaturated monobasic acids and styrene with a compound having an unsaturated group and an epoxy resin in one molecule in the presence of one or more catalysts selected from the group comprising lithium naphthenate, zirconium naphthenate, chromium naphthenate, chromium acetylacetonate, chromium chloride and triphenylphosphine.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photosensitive resin and a photosensitive resin composition. More specifically, stability after preparation of the composition, thermal stability in the solvent volatilization step, dryness to the touch after volatilizing the solvent, excellent developability in a dilute aqueous alkaline solution, and a coating film after final curing, Flexibility, heat resistance, solder heat resistance,
The present invention relates to a photosensitive resin and a photosensitive resin composition which are excellent in adhesion, water resistance, chemical resistance and the like.

[0002]

2. Description of the Related Art Conventionally, a solder resist in the production of a printed wiring board has been manufactured by a method of screen-printing a heat- or ultraviolet-curable resist ink, but at present, from the viewpoint of productivity, an alkali-developing liquid solder photoresist. Has been moved to. For example, Japanese Patent Publication 1-543
No. 90 discloses a liquid resist ink composition developable with an aqueous alkaline solution, which is obtained by reacting a reaction product of a novolac type epoxy compound and an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic acid anhydride. Photocurable resin,
A liquid resist ink composition containing a photopolymerization initiator, a diluent, and an epoxy compound having two or more epoxy groups has been proposed, and is currently the mainstream in rigid substrate applications such as a glass epoxy substrate.

In the process, a resist ink composition is applied onto a printed wiring board, the solvent is volatilized, the solution is exposed through a negative film, and the solution is developed with a dilute aqueous alkali solution. However, there is a drawback in that the dryness to the touch of the coating film after the resist ink composition is applied onto a printed wiring board and the solvent is volatilized may be insufficient for the use of a negative film. Therefore, for the purpose of improving touch dryness, many proposals have been made to use another copolymer resin instead of the photocurable resin (for example, Japanese Patent Publication No. 7-92).
Japanese Patent No. 603, Japanese Patent No. 2547883, Japanese Patent No. 254
7884 and the like).

In all of these, a copolymer containing (meth) acrylic acid is further reacted with glycidyl (meth) acrylate. Glycidyl (meth) acrylate is added to a part of the carboxyl groups of the copolymer resin. When mixed with a photopolymerization initiator, a diluent and an epoxy compound to form a liquid resist ink composition, the reaction between the carboxyl group in the copolymer resin and the epoxy compound is at room temperature due to the influence of a reaction catalyst such as an amine-based catalyst. However, there is a problem that the viscosity change with time is large and the storage stability is insufficient, and the thermal stability in the step of heating and volatilizing the solvent is insufficient.

[0005]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide stability after preparation of a composition, thermal stability in a solvent volatilization step, dryness to the touch after volatilization of a solvent, and development with a dilute alkaline aqueous solution. To provide a photosensitive resin and a photosensitive resin composition which are excellent in flexibility and have excellent flexibility, heat resistance, solder heat resistance, adhesion, water resistance, chemical resistance, etc. It is in.

[0006]

According to the invention of claim 1, a copolymer (I) obtained by copolymerizing at least one or more unsaturated monobasic acid with styrene is added to lithium naphthenate and naphthenic acid. Obtained by reacting a compound having an unsaturated group and an epoxy group in the molecule in the presence of at least one catalyst selected from the group consisting of zirconium, chromium naphthenate, chromium acetylacetonate, chromium chloride and triphenylphosphine. It is a photosensitive resin. According to the invention of claim 2, 0.1 to 0.8 equivalent of a compound having an unsaturated group and an epoxy group in the molecule is reacted with 1 equivalent of a carboxyl group in the copolymer (I). It is the described photosensitive resin. In the invention of claim 3, the copolymer (I) comprises at least one or more unsaturated monobasic acid, styrene,
The (meth) acrylic acid, acrylonitrile, and one or more kinds selected from the group consisting of alkyl (meth) acrylates represented by the following general formula (1) are copolymerized with each other. It is a photosensitive resin. Formula (1): (wherein, n = illustrates a an integer from 2 to _{12) CH 2 = CHCOOC n H 2n} + 1 fourth aspect of the present invention, the weight average molecular weight of copolymer (I), 5000 to The photosensitive resin according to any one of claims 1 to 3, which is 80,000. In the invention of claim 5, the compound having an unsaturated group and an epoxy group in the molecule is
The photosensitive resin according to any one of claims 1 to 4, which is glycidyl (meth) acrylate. Claim 6
The invention of (A) is (A) the photosensitive resin according to any one of claims 1 to 5, (B) an epoxy resin, (C) a photopolymerization initiator, and (D) a polymerizable unsaturated compound and / or A photosensitive resin composition containing a solvent. In the invention of claim 7, the epoxy resin (B) is 1 to 5 relative to the composition.
The photosensitive resin composition according to claim 6, which is blended in an amount of 0% by weight. The invention of claim 8 is the photosensitive resin composition according to claim 6 or 7, wherein the photopolymerization initiator (C) is blended in an amount of 0.5 to 20% by weight based on the composition. The invention of claim 9 is characterized in that (D) the polymerizable unsaturated compound and / or the solvent is blended in an amount of 5 to 80% by weight based on the composition.
9. The photosensitive resin composition according to any one of items 1 to 8.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Copolymer (I) in the present invention
Is obtained by copolymerizing at least one kind of unsaturated monobasic acid and styrene. Examples of the unsaturated monobasic acid include unsaturated carboxylic acids having an ethylenically unsaturated double bond such as acrylic acid, methacrylic acid, crotonic acid, o, m, p-vinylbenzoic acid, cinnamic acid, sorbic acid, Examples thereof include acrylic acid dimers, monomethylmalate, monopropylmalate, monobutylmalate, and monocarboxylic acids such as α-position haloalkyl, alkoxyl, halogen, nitro, and cyano-substituted products of (meth) acrylic acid. In addition, in order to obtain the copolymer (I), a polymerizable unsaturated monomer other than the unsaturated monomer may be used in combination. Specific examples thereof include α-, o-, m-, p-alkyl, nitro, cyano, amide and ester derivatives of styrene; butadiene, 2,3-dimethylbutadiene, isoprene,
Dienes such as chloroprene; methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid-
n-propyl, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth) acrylic acid-s
ec-butyl, tert-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate , Lauryl (meth) acrylate, dodecyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, dicyclohexyl (meth) acrylate, (meth) acrylic Isobornyl acid,
Adamantyl (meth) acrylate, allyl (meth) acrylate, propargyl (meth) acrylate, phenyl (meth) acrylate, naphthyl (meth) acrylate, anthracenyl (meth) acrylate, anthraninonyl (meth) acrylate , Piperonyl (meth) acrylate, salicyl (meth) acrylate, furyl (meth) acrylate,
Furfuryl (meth) acrylate, tetrahydrofuryl (meth) acrylate, pyranyl (meth) acrylate, benzyl (meth) acrylate, phenethyl (meth) acrylate, cresyl (meth) acrylate, (meth) acrylic acid-1 , 1,1-trifluoroethyl, perfluoroethyl (meth) acrylate, perfluoro-n-propyl (meth) acrylate, perfluoro- (meth) acrylate
i-Propyl, triphenylmethyl (meth) acrylate, cumyl (meth) acrylate, (meth) acrylic acid 3
-(N, N-dimethylamino) propyl, (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-
(Meth) acrylic acid esters such as 2-hydroxypropyl; (meth) acrylic acid amide, (meth) acrylic acid N, N-dimethylamide, (meth) acrylic acid N, N
-(Meth) acrylic acid amides such as diethylamide, (meth) acrylic acid N, N-dipropylamide, (meth) acrylic acid N, N-di-isopropylamide, (meth) acrylic acid anthracenylamide; ) Vinyl compounds such as anilide acrylic acid, (meth) acryloyl nitrile, acrolein, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N-vinylpyrrolidone, vinyl pyridine and vinyl acetate; diethyl citraconic acid, diethyl maleate, Unsaturated dicarboxylic acid diesters such as diethyl fumarate and diethyl itaconic acid; N
Monomaleimide compounds such as -phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, N- (4-hydroxyphenyl) maleimide; N-
(Meth) acryloyl phthalimide and the like can be mentioned.

Among them, especially the copolymer (I) is
At least one or more unsaturated monobasic acid, styrene,
Copolymerization of one or more selected from the group consisting of (meth) acrylic acid, acrylonitrile, and an alkyl (meth) acrylate represented by the following general formula (1) shows thermal stability in the solvent volatilization step. , Dryness to the touch after volatilizing the solvent, excellent developability with dilute alkali, and the coating film after curing has flexibility, heat resistance, water resistance, adhesion, solder heat resistance, electroless gold plating resistance and It is preferable because it is a photosensitive resin having a well-balanced PCT resistance.

General formula (1): CH ₂ ═CHCOOC _n H _{2n + 1} (wherein n is an integer of 2 to 12)

The copolymer (I) can be synthesized by a known solution polymerization method. The solvent used is not particularly limited as long as it is inert to radical polymerization,
A commonly used organic solvent can be used.
Specific examples thereof include ethyl acetate, isopropyl acetate,
Ethylene glycol monoalkyl ether acetates such as cellosolve acetate and butyl cellosolve acetate; Diethylene glycol monoalkyl ether acetates such as diethylene glycol monomethyl ether acetate, carbitol acetate and butyl carbitol acetate; Propylene glycol monoalkyl ether acetates and dipropylene glycol monoalkyl Acetate esters such as ether acetates; diethylene glycol dialkyl ethers such as diethylene glycol dialkyl ethers, methyl carbitol, ethyl carbitol, butyl carbitol; triethylene glycol dialkyl ethers; propylene glycol dialkyl ethers; dipropylene glycol dialkyl ether Kind Ethers such as 1,4-dioxane and tetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; hydrocarbons such as benzene, toluene, xylene, octane and decane; petroleum ether, petroleum naphtha, hydrogenated petroleum Petroleum solvents such as naphtha and solvent naphtha; lactic acid esters such as methyl lactate, ethyl lactate and butyl lactate; dimethylformamide and N-methylpyrrolidone. These solvents may be used alone or in combination of two or more. The amount of the solvent used is 30 to 1000 parts by weight, preferably 50 to 800 parts by weight, based on 100 parts by weight of the photosensitive resin.
Parts by weight. Outside this range, it becomes difficult to control the molecular weight.

The radical polymerization initiator is not particularly limited as long as it can initiate radical polymerization, and a commonly used organic peroxide catalyst or azo compound can be used. Specific examples thereof are those classified into known ketone peroxides, peroxyketals, hydroperoxides, diallyl peroxides, diacyl peroxides, peroxyesters, peroxydicarbonates, and azo compounds are also effective. is there. Specific examples include benzoyl peroxide, dicumyl peroxide, diisopropyl peroxide, di-t-butyl peroxide, t-butylperoxybenzoate, t-hexylperoxybenzoate, t-butylperoxy-2-ethylhexa. Noate, t-hexylperoxy-2-ethylhexanoate, 1,1-bis (t-butylperoxy) -3,
3,5-Trimethylcyclohexane, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyl-
3,3-isopropylhydroperoxide, t-butylhydroperoxide, dicumyl peroxide, dicumylhydroperoxide, acetyl peroxide, bis (4-t-butylcyclohexyl) peroxydicarbonate, diisopropylperoxydicarbonate , Isobutyl peroxide, 3,3,5-trimethylhexanoyl peroxide, lauryl peroxide, 1,1-bis (t-butylperoxy) 3,3
5-Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane, azobisisobutyronitrile, azobiscarbonamide and the like can be used. A radical initiator having an appropriate half-life is selected according to the polymerization temperature.

The amount of the radical polymerization initiator used is 0.5 based on 100 parts by weight of the total amount of the radically polymerizable unsaturated compound.
-20 parts by weight, preferably 1-10 parts by weight.

As for the polymerization method, the unsaturated monomer and the radical polymerization initiator may be dissolved in a solvent and the temperature may be raised with stirring to carry out the polymerization reaction, or the unsaturated monomer containing the radical polymerization initiator may be added. May be added dropwise to the solvent which is heated and stirred. Further, the unsaturated monomer may be dropped while the radical polymerization initiator is added to the solvent and the temperature is raised. The reaction conditions can be freely changed depending on the target molecular weight.

The weight average molecular weight of the copolymer (I) is 500.
It is preferably 0 to 80,000, preferably 7,000 to 60,000. When the weight average molecular weight is less than 5,000, tack and gold plating resistance are poor, and when it exceeds 80,000, compatibility with the unsaturated monomer and / or solvent is poor.

In the present invention, as the compound having an unsaturated group and an epoxy group in the molecule, known compounds can be used, and a typical example thereof is glycidyl (meth).
Acrylate, allyl glycidyl ether, styrene-
Examples thereof include p-glycidyl ether, and (meth) acrylates having an alicyclic epoxy group such as cyclomers A200, M100, and M101 manufactured by Daicel Chemical Industries, Ltd. Glycidyl methacrylate is particularly preferable because the raw material is inexpensive.

The amount of addition of the compound having an unsaturated group and an epoxy group in the molecule is determined by the carboxyl group 1 in the copolymer (I).
0.1-0.8 equivalents, preferably 0.2-
It is 0.6 equivalent. If the addition amount of the compound having an unsaturated group and an epoxy group in the molecule is less than 0.1 equivalent, the sensitivity of the photosensitive resin is insufficient, and if it is more than 0.8 equivalent, the carboxyl group of the photosensitive resin The amount becomes too small and the developability becomes insufficient.

The catalyst used for the reaction of the carboxyl group in the copolymer (I) with the compound having an unsaturated group and an epoxy group in the molecule is lithium naphthenate, zirconium naphthenate, chromium naphthenate, acetylacetate. It is one or more selected from natechromate, chromium chloride and triphenylphosphine. The reaction can be carried out by a known method such as mixing the copolymer (I), a compound having an unsaturated group and an epoxy group in the molecule and the catalyst in a solvent, heating and stirring. .

The amount of the catalyst used is preferably 0.01 to 1% by weight based on the total amount of the copolymer (I) and the compound having an unsaturated group and an epoxy group in the molecule. The reaction temperature is preferably 60 to 150 ° C. The reaction time is preferably 5 to 60 hours. In this way
A compound having an unsaturated group and an epoxy group in the molecule can be reacted with the copolymer (I) to obtain the photosensitive resin of the present invention.

Known solvents can be used in the reaction, and ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; dipropylene glycol dimethyl ether, dipropylene glycol dimethyl ether,
Glycol ethers such as dipropylene glycol dimethyl ether and dipropylene glycol diethyl ether; Esters such as ethyl acetate, butyl cellosolve acetate and carbitol acetate; Aliphatic hydrocarbons such as octane and decane; Petroleum ether, petroleum naphtha, hydrogenated petroleum Organic solvents such as petroleum solvents such as naphtha and solvent naphtha can be mentioned.

The present invention also provides, in another aspect, (A)
The present invention provides a photosensitive resin composition containing the photosensitive resin, (B) epoxy resin, (C) photopolymerization initiator, and (D) polymerizable unsaturated compound and / or solvent.

The epoxy resin (B) has, for example, one or more epoxy groups in one molecule, and is bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, phenol novolac. Type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene-phenol novolac type epoxy resin, phenol-cresol novolac co-condensation type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin or halogenated epoxy compounds thereof , Triphenylol methane type epoxy resin, alkyl-substituted triphenylol methane type epoxy resin, tetraphenylol ethane type epoxy resin, etc. Epoxy resins obtained by reacting a down, polyfunctional hydroxy naphthalenes is reacted with epichlorohydrin obtained epoxy resin, silicone-modified epoxy resin, .epsilon.-caprolactone-modified epoxy resin,
Examples thereof include glycidyl amine type epoxy resins obtained by the reaction of epichlorohydrin with primary or secondary amines, and heterocyclic epoxy resins such as triglycidyl isocyanate. You may use together 1 type (s) or 2 or more types of these epoxy resins. Further, it is also effective to use an isocyanate-modified epoxy resin for the purpose of improving Toughness while ensuring Tg, and to use a phosphorus-containing epoxy resin from the viewpoint of imparting flame retardancy. Specific examples of the isocyanate-modified epoxy resin are those obtained by synthesizing the above epoxy resin and an isocyanate compound in the presence of an oxazolidone-forming catalyst. The details are shown in JP-B-53-457.
57, JP-A-5-43657 and the like. Commercially available products of the isocyanate-modified epoxy resin having an oxazolidone ring are trade names XAC4151 and X.
AC4152 (manufactured by Asahi Kasei Epoxy Co., Ltd.) and the like.

The purpose of using the epoxy resin (B) as the thermosetting component is to improve various properties as a solder resist such as adhesion, heat resistance and plating resistance.

The epoxy resin (B) may be used alone or as a mixture of two or more kinds, and the amount of the epoxy resin (B) contained in the composition of the present invention is 1 to 50% by weight in the composition, preferably. 3 to 45% by weight.

When the (B) epoxy resin as the thermosetting component is used, it is desirable to use an epoxy resin curing agent together in order to further improve properties such as adhesion, chemical resistance and heat resistance. Examples of such epoxy resin curing agents include imidazole derivatives, phenol derivatives, dicyandiamide, dicyandiamide derivatives, hydrazide derivatives, amines, acid anhydrides and the like. The curing agent may be used alone or in combination of two or more. The amount of the curing agent used is preferably such that the active hydrogen amount of the curing agent is 0.5 to 1.2 equivalents relative to the epoxy groups of the epoxy resin.

Specific examples of the photopolymerization initiator (C) include benzoins, acetophenones, anthraquinones, thioxanthones and benzophenones. For example, benzoins include benzoin, benzoin methyl ether and benzoin isopropyl ether. Derivatives such as acetophenones, acetophenone for acetophenones, derivatives of 2,2-dimethoxy-2-phenylacetophenone, and anthraquinones for 2-methylanthraquinone, 2-chloroanthraquinone, 2-ethylanthraquinone, 2-t-
Derivatives such as butylanthraquinone, thioxanthones for thioxanthones, derivatives such as 2,4-dimethylthioxanthone, benzophenones for benzophenones, 4
-Benzoyl-4'-methyldiphenyl sulfide,
There are derivatives such as 4,4′-dichlorobenzophenone and N, N-dimethylaminobenzophenone, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide, which can be used alone or in combination of two or more kinds. Further, the photopolymerization initiator (C) may be used in combination with a known photosensitizer. Specifically, triethanolamine, tripropanolamine, triethylamine,
N, N-dimethylamino acid benzoic acid ethyl ester,
N, N-dimethylaminobenzoic acid isoamyl ester,
Examples include pentyl-4-dimethylaminobenzoate and the like. The above-mentioned photosensitizers may be used alone or in combination of two or more.

The (D) polymerizable unsaturated compound and / or solvent is used for the purpose of improving the curability with respect to active energy rays and / or the coatability when the photosensitive resin composition is used as a resist ink. Is.
As the polymerizable unsaturated compound, active energy ray curable monomers are preferable, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
N-pyrrolidone, N-acryloylmorpholine, N, N-
Dimethylacrylamide, N, N-diethylacrylamide, N, N-dimethylaminoethyl acrylate, N, N-
Dimethylaminopropyl acrylate, methoxy polyethylene glycol acrylate, ethoxy polyethylene glycol acrylate, melamine acrylate, phenoxyethyl acrylate, phenoxypropyl acrylate, ethylene glycol diacrylate, dipropylene glycol diacrylate, polydipropylene glycol diacrylate, trimethylolpropane triacrylate, penta Erythritol triacrylate,
Examples thereof include pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, glycerin diacrylate, isobornyl acrylate, dicyclopentenyloxyethyl acrylate and various methacrylates corresponding thereto. You may use together 1 type (s) or 2 or more types of these polymeric unsaturated compounds.

On the other hand, as the solvent, the solvent used in the above reaction can be used. In addition to the above solvents, special solvents such as N-methylpyrrolidone and N, N-dimethylformamide may also be used.

The polymerizable unsaturated compound (D) and / or the solvent are used alone or as a mixture of two or more kinds. The amount of the polymerizable unsaturated compound (D) and / or the solvent used is preferably 5 to 80% by weight based on the composition. If the amount of the component (D) used is less than 5% by weight, the photosensitivity is too low, while if it exceeds 80% by weight, the viscosity becomes too low when the photosensitive resin composition is used as a resist ink, and a cured coating film is obtained. As a result, the resistance becomes insufficient.

In addition, when the photosensitive resin composition of the present invention is used as a liquid resist ink, if necessary, an inorganic filler such as silica, calcium carbonate, barium sulfate, clay, talc, or phthalocyanine green. ,
Color pigments such as phthalocyanine blue, titanium oxide and carbon black, various additives such as defoaming agents and leveling agents, hydroquinone, resorcinol, catechol, pyroganol, hydroquinone monomethyl ether, t-
A polymerization inhibitor such as butyl catechol or phenothiazine may be used.

[0030]

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples. In addition, "part" in each example shows a weight standard. The invention is not limited to these examples.

Synthesis Example 1 116 g of propylene glycol monomethyl ether acetate (PGM-AC) was placed in a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer, and a gas inlet tube, and the mixture was stirred with nitrogen substitution and heated to 120 ° C. did. Next, t-butylperoxy-2-ethylhexanoate (Perbutyl O manufactured by NOF CORPORATION) was added to a monomer mixture consisting of styrene 0.5 mol (52 g) and methacrylic acid 0.5 mol (43 g). 4.5 for 100 copies
What was added (4.3 g) was added dropwise from the dropping funnel over 2 hours, stirred at 120 ° C for 2 hours, and further heated at 130 ° C for 2 hours.
Aging was performed for a time to obtain a copolymer. Next, the inside of the flask was replaced with air, and 0.43 g of chromium acetylacetonate was added, and 0.2 g of glycidyl methacrylate was added.
Mol (28.4 g) to which 0.145 g of hydroquinone was added was added to the above-mentioned aged product, and 120
The reaction was continued at 6 ° C. for 6 hours to obtain a photosensitive resin-1 having a solid content acid value = 135. The weight average molecular weight measured by GPC was 14,800.

Synthesis Example 2 PGM-AC (114 g) was placed in a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer, and a gas introduction tube.
The mixture was stirred while being replaced with nitrogen and the temperature was raised to 80 ° C. Next, 0.49 mol of styrene (51 g), 0.25 mol of methacrylic acid (21.5 g), and 0.24 mol of acrylic acid (17.3).
g), 0.01 mol of acrylonitrile (0.53 g),
0.01 mol of 2-ethylhexyl methacrylate (1.
98 g), and 4.5 parts (4.15 g) of azobisisobutyronitrile added to 100 parts of the monomer mixture are added dropwise from the dropping funnel over 2 hours and stirred at 80 ° C. for 5 hours. Then, aging was further performed at 130 ° C. for 2 hours to obtain a copolymer. Next, the inside of the flask was replaced with air, and 0.24 g of chromium naphthenate was added.
Glycidyl methacrylate 0.2 mol (2
8.4 g) to which 0.145 g of hydroquinone was added was put into the aged product, and the reaction was continued at 120 ° C. for 6 hours to obtain a photosensitive resin-2 having a solid content acid value = 133. The weight average molecular weight measured by GPC is 3110.
It was 0.

Synthesis Example 3 113 g of propylene glycol monomethyl ether acetate (PGM-AC) was placed in a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer, and a gas introduction tube, and the temperature was raised to 120 ° C. with stirring while substituting nitrogen. did. Next, t-butylperoxy-2-ethylhexanoate (Perbutyl O manufactured by NOF CORPORATION) was added to a monomer mixture consisting of styrene 0.5 mol (52 g) and methacrylic acid 0.5 mol (43 g). 4.5 for 100 copies
Part (4.3 g) was added dropwise from the dropping funnel over 2 hours, and the mixture was further stirred at 120 ° C for 2 hours and further heated at 130 ° C.
Was aged for 2 hours to obtain a copolymer. Next, the inside of the flask was replaced with air, 0.36 g of triphenylphosphine was added, and 0.2 g of glycidyl methacrylate was added.
Mol (28.4 g) to which 0.145 g of hydroquinone was added was added to the above-mentioned aged product, and 120
The reaction was continued at 6 ° C. for 6 hours to obtain a photosensitive resin-3 having a solid content acid value = 135. The weight average molecular weight measured by GPC was 27900.

Comparative Synthesis Example 1 PGM-AC (116 g) was placed in a flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas introduction tube.
The mixture was stirred while being replaced with nitrogen and heated to 120 ° C. Then, t-butyl hydroperoxide (Perbutyl O manufactured by NOF Corporation) was added to a monomer mixture consisting of 0.5 mol (52 g) of styrene and 0.5 mol (43 g) of methacrylic acid per 100 parts of the monomer mixture. What added 5 parts (4.3g) was dripped from the dropping funnel in 2 hours, and also 12
The mixture was stirred at 0 ° C. for 2 hours and aged. Up to this point, the same operation as in Synthesis Example 1 was performed. Next, the inside of the flask was replaced with air, and the acetylacetonate chromium of Synthesis Example 1 was replaced with triethylamine 0.43 g and added.
What added 0.145 g of hydroquinone to 0.2 mol (28.4 g) of glycidyl methacrylate was put into the above-mentioned aged, and the reaction was continued at 120 ° C. for 6 hours to obtain a photosensitive resin having a solid content acid value = 134. Got 4. GP
The weight average molecular weight measured by C was 15,000.

Examples 1 to 3 and Comparative Example 1 A photosensitive resin composition was prepared by kneading the photosensitive resins obtained from the above-mentioned synthetic examples and comparative synthetic examples with a three-roll mill in accordance with the compounding ratio shown in Table 1. Was prepared. Next, the photosensitive resin composition is applied to a pre-degreased printed circuit board by a screen printing method so as to have a dry film thickness of 30 to 40 μm, and after preliminary drying at 80 ° C. for 20 minutes,
It cooled to room temperature and the dry coating film was obtained. A negative film having a resist pattern was brought into close contact with this coating film, exposed to 350 mJ / cm ² using an ultraviolet exposure device, the negative film was removed, and a spray pressure of 0.2 MPa (2 MPa was used using a 1% sodium carbonate aqueous solution. Development was carried out for 60 seconds at 0.0 kgf / cm ² ) to dissolve and remove the unexposed portion. Then, using a hot air drier, heat curing at 150 ° C. for 30 minutes to give the following adhesion, solder heat resistance, electroless gold plating resistance, and P resistance.
A test piece having CT property was obtained. The obtained test piece was evaluated for various physical properties according to the test methods described below. Also,
Separately from this, a flexibility test, developability, and storage stability of the photosensitive resin composition were also evaluated. The evaluation results of these tests are shown in Tables 2 and 3. However, the developability was evaluated by using test pieces with different preliminary drying times at 80 ° C. as test pieces. The storage stability of the photosensitive resin composition was confirmed by measuring the change in viscosity during storage at 25 ° C.

[0036]

[Table 1]

* 1: 1,3,5-triglycidyl isocyanurate [manufactured by Nissan Kagaku KK] * 2: Irgacure 907, 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropanone-1 [Ciba Geigy] * 3: Kayacure DETX-S, 2,4-diethylthioxanthone [Nippon Kayaku Co., Ltd.] * 4: Light acrylate TMP- A, trimethylolpropane triacrylate [manufactured by Kyoeisha Chemical Co., Ltd.] * 5: Aerosil 300, [manufactured by Nippon Aerosil Co., Ltd.]

(Developability) Predrying time is 20 minutes, 40
Minutes, 60 minutes, 80 minutes, 100 minutes dry coating film 1%
Spray pressure 0.2MPa using sodium carbonate aqueous solution
Development was performed at (2.0 kgf / cm ² ) for 60 seconds, and the presence or absence of a coating film after development was observed and evaluated according to the following criteria. ◯: Ink was completely removed during development and development was possible. X: Some parts cannot be developed during development.

(Adhesion) According to the test method of JIS D 0202, the cured coating film is cross-cut in a grid pattern,
Then, the state of peeling after the peeling test with cellophane tape was visually judged. The evaluation was performed based on the following criteria. ◯: No peeling at all. Δ: The cross cut part was slightly peeled off. X: The cured coating film is peeled off.

(Solder Heat Resistance) According to the test method of JIS C 6481, the test piece was immersed in a solder bath at 260 ° C. for 3 seconds for 10 seconds, taken out, and then the change in appearance was observed. The evaluation was performed based on the following criteria. ○: No change in appearance. Δ: Discoloration of the cured coating film was observed. X: The cured coating film has floating, peeling, and solder submersion.

(Electroless Gold Plating Resistance) As a pretreatment of a test piece, it is immersed in an acidic degreasing solution at 30 ° C. → immersion rinsing → soft etching treatment → immersion rinsing → catalyst (immersion in 30 ° C. nickel plating catalyst solution for 7 minutes). ) → The immersion washing process was performed. Next, in the electroless nickel plating step, the test piece is dipped in a nickel plating solution (85 ° C., PH = 4.6) for 20 minutes → acid dipped for 1 minute (10 vol% sulfuric acid aqueous solution at room temperature) →
Immersion water washing is performed, and finally, as an electroless gold plating step, the test piece is immersed in a gold plating solution (95 ° C., PH = 6, 3% by volume of potassium gold cyanide for 3 minutes) → immersion water washing → 6
Immersion in hot water at 0 ° C Washing with water → After thoroughly washing with water → Drain the water well →
Electroless gold plating was performed in the drying step, and the test piece was observed for changes in appearance and peeling test using cellophane tape. The evaluation was performed based on the following criteria. Good: No change in appearance and no peeling of the coating film. Δ: No change in appearance, but slight peeling of the coating film is observed. X: The coating film was found to be floating and the plating was submerged, and the coating film was largely peeled off in the peeling test.

(PCT test) The test piece was held at 121 ° C. for 2 at
m, the appearance of the coating film after standing for 100 hours in a saturated steam atmosphere was judged. The evaluation was performed based on the following criteria. ○: The coating film does not swell or peel off. X: Swelling or peeling.

(Flexibility test) A polyimide film (thickness: 100 μm) was coated with the above-mentioned photosensitive resin composition to a film thickness of 15 μm.
It is applied to and dried → exposed → developed → heated, and the obtained test piece is 180 ° from the back surface so that the resist-cured surface is on the outside.
After bending, the appearance of the resist coating film was observed. The evaluation was performed based on the following criteria. ⊚: No change. ◯: Slight streaks remain. Δ: Streaks remain. X: A crack occurs.

(Change in Viscosity at 25 ° C.) Based on the viscosity immediately after preparation of the photosensitive resin composition, the rate of increase in viscosity after storage at 40 ° C. for 24 hours was measured and evaluated according to the following criteria. A: 0 to 10% O: 11 to 50% B: 51 to 100% X: 101% or more

[0045]

[Table 2]

[0046]

[Table 3]

As is clear from the evaluation results of Tables 2 and 3, the photosensitive resin composition of the present invention is excellent in storage stability, thermal stability in the solvent drying step and alkali developability, and its cured product is Adhesion, solder heat resistance, electroless gold plating resistance, P resistance
It can be seen that the CT property and flexibility are excellent.

[0048]

EFFECTS OF THE INVENTION According to the present invention, the stability after preparation of the composition, the thermal stability in the solvent volatilization step, the dryness to the touch after volatilizing the solvent, the developability in a dilute aqueous alkaline solution, and the final The cured coating film has flexibility, heat resistance, solder heat resistance, adhesion,
Provided are a photosensitive resin and a photosensitive resin composition having excellent water resistance and chemical resistance. The composition of the present invention is particularly suitable for use as a solder resist ink for printed wiring boards.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuo Otani             673-8 Kubojima, Kumagaya City, Saitama Prefecture F term (reference) 2H025 AA04 AA11 AA13 AA14 AB15                       AB20 AC01 AD01 BC13 BC42                       BC53 BC83 BC86 BC92 BJ10                       CA00 CB30 CC17                 4J036 AC01 AC02 AC05 AD08 AF06                       AF07 EA04 EA05 FB01 FB03                       GA26 HA02 JA01 JA10                 4J100 AB02P AJ02Q AJ02R AM02S                       BA03H BA15H CA04 CA06                       HA62 HB29 HC25 HC27 HC39                       HC75 HE14 HE41 JA37                 5E314 AA27 AA32 AA49 BB11 BB12                       FF01 GG01 GG08 GG14

Claims (9)

[Claims] 1. A copolymer (I) obtained by copolymerizing at least one or more unsaturated monobasic acid with styrene,
A compound having an unsaturated group and an epoxy group in the molecule in the presence of one or more catalysts selected from the group consisting of lithium naphthenate, zirconium naphthenate, chromium naphthenate, chromium acetylacetonate, chromium chloride and triphenylphosphine. A photosensitive resin obtained by reacting with. 2. A compound having an unsaturated group and an epoxy group in the molecule is reacted in an amount of 0.1 to 0.8 equivalents to 1 equivalent of a carboxyl group in the copolymer (I). Photosensitive resin. 3. The copolymer (I) comprises at least one or more unsaturated monobasic acid, styrene, (meth) acrylic acid, acrylonitrile and an alkyl (meth) acrylate represented by the following general formula (1). The photosensitive resin according to claim 1, which is obtained by copolymerizing one or more selected from the group consisting of: Formula _{(1): CH 2 = CHCOOC} n H 2n + 1 ( wherein represents an integer of n = 2 to 12) 4. The weight average molecular weight of the copolymer (I) is 5
The photosensitive resin according to any one of claims 1 to 3, which is 000 to 80,000. 5. The photosensitive resin according to claim 1, wherein the compound having an unsaturated group and an epoxy group in the molecule is glycidyl (meth) acrylate. 6. (A) The photosensitive resin according to claim 1, (B) an epoxy resin, (C) a photopolymerization initiator, and (D) a polymerizable unsaturated compound and / Alternatively, a photosensitive resin composition containing a solvent. 7. The photosensitive resin composition according to claim 6, wherein the epoxy resin (B) is blended in an amount of 1 to 50% by weight based on the composition. 8. The photosensitive resin composition according to claim 6, wherein the photopolymerization initiator (C) is blended in an amount of 0.5 to 20% by weight based on the composition. 9. The photosensitive resin composition according to claim 6, wherein (D) the polymerizable unsaturated compound and / or the solvent is blended in an amount of 5 to 80% by weight based on the composition. .