JPH03153768A - Photosensitive thermoset resin composition, solder resist resin composition, and cured product thereof - Google Patents

Abstract

PURPOSE:To prepare a photosensitive thermoset resin compsn. excellent in the curability, heat resistance, etc., and developable with a dil. aq. alkali soln. by compounding a carboxylated ethylenically unsatd. prepolymer, a specific copolymerizable compd., a photopolymn. initiator, and a diluent. CONSTITUTION:A photosensitive thermoset resin compsn., suitable for a solder resist compsn., is prepd. by compounding: an ethylenically unsatd. prepolymer having a carboxyl group in the molecule (e.g. a reaction product of an epoxy resin, an acrylic resin, and maleic acid); a compd. of the formula (wherein R1 is lower alkyl; R2 is H or CH3; (a+b) is 6; (a) is 1-5; and (b) is 1-5) (e.g. acrylic modified alkylated melamine resin); a photopolymn. initiator (e.g. benzophenone); and a diluent comprising a photopolymerizable vinylic monomer (e.g. 2-hydroxyethyl acrylate) and (or) an org. solvent.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to novel and useful photosensitive thermosetting resin compositions, solder resist resin compositions, and cured products thereof. Ethylenically unsaturated group-containing prepolymer having a carboxyl group in the compound represented by the general formula [I] (a photocurable, thermosetting compound containing an odor, a photopolymerization initiator, and a diluent as essential components) and a resin composition suitable for a solder resist that has excellent heat resistance, adhesion, and chemical resistance and can be developed with a weak alkaline aqueous solution, and is particularly suitable for manufacturing consumer printed wiring boards, industrial printed wiring boards, etc., and its cured product. .

(Prior Art) In recent years, ultraviolet curable compositions have been widely used for reasons such as resource saving, energy saving, improved workability, and improved productivity. In the field of printed wiring board processing, various inks such as solder resist inks and marking inks have been shifting from conventional thermosetting compositions to ultraviolet curable compositions for the same reason. Among these, solder resist inks were the first to transition to UV-curable compositions.

(Problems to be Solved by the Invention) Screen printing methods have often been used to form resist patterns on printed wiring boards, but when such screen printing methods are used, bleed, smearing, or Phenomena such as sag and sag occur, and as a result, it is no longer possible to cope with the recent increase in the density of printed wiring boards.

To solve these problems, there are dry film type photoresists and liquid developable resist inks, but dry film type photoresists tend to produce air bubbles during thermocompression bonding and have poor heat resistance. There are also problems such as concerns about adhesion and high price. On the other hand, currently commercially available liquid resists use organic solvents as developing solutions, resulting in problems with air pollution, expensive solvents, and problems with solvent resistance and acid resistance.

(Means for Solving the Problems) In order to solve the problems described above, the present inventors have conducted extensive research and found that a dilute alkali resin with excellent heat resistance, adhesion, chemical resistance, plating resistance, and electrical insulation properties has been developed. Can be developed with an aqueous solution.
We have succeeded in providing a resin composition suitable for solder resist.

That is, the present invention relates to an ethylenically unsaturated group-containing prepolymer (A) having a carboxyl group in the molecule and a compound having the general formula [
I] (In formula CHI, R+ is a lower alkyl group, preferably C
HI or C4H11, R2 is H or CHz. a+
b is 6, a is a number from 1 to 5, and b is a number from 1 to 5) and a photopolymerization initiator (Q and a diluent (
The present invention relates to a photosensitive thermosetting resin composition, particularly a solder resist resin composition, and a cured product thereof, which contains a photopolymerizable vinyl compound and/or an organic solvent.

Each component of the photosensitive thermosetting resin composition of the present invention will be explained below.

The above-mentioned ethylenically unsaturated group-containing prepolymer having a carboxyl group in the molecule can be used for epoxy resins [e.g.
Novolak type epoxy resin (manufactured by Tobu Kasei, YDCN-
701, YDCN-704, YDPN-638, YDP
N-602; Manufactured by Tau Chemical Co., Ltd., DEN-431,
DEN-439; Manufactured by Chipa Geigy, EPN-113
8, EPN-1235, EPN1299; Dainippon Ink & Chemicals, N-730°N-770, N-865, N
-665: N-673, N-695, VH-4150,
VH-4240, VH-4440; manufactured by Nippon Kayaku ■, EO
CN-120, EOCN-104, BRPN-1020
; Manufactured by Asahi Kasei Kogyo, ECN-265, ECN-293, E
CN-285, ECN-299, etc.) Bisphenol A type, bisphenol F type, hydrogenated bisphenol A type, brominated bisphenol A type, amide 7 group-containing, alicyclic or glycidyl ether type epoxy resin such as polybutadiene modified epoxy resin ( For example, Epicoat 828 manufactured by Yuka Shell
, Epicort 1007, Epicort 80-7; manufactured by Dainippon Ink and Chemicals, Evicron 84o, Evicron 860
．． Epicron 3050. Evicron 830; manufactured by Dow Chemical Company, DER-330°DER-337, DER-
361; Daicel Chemical Industries, Ltd. hepoxide 2021.
Celloxide 3000; manufactured by Mitsubishi Gas Chemical, TETRAD
-X, TETRAD-C; manufactured by Nippon Soda, EPB-13,
EPB-27; manufactured by Tobu Kasei, YD-116, YD-12
8, YD-013, YD-020, YDG-414,5
T-3000, 5T-1101YDF-190, YDF
-2004, YDF-2007; manufactured by Ciba Geigy,
GY-260, 0Y-255, XB2615; Dow
Made by Chemical, DER-332, DER-662, DER
-542, etc.) and tris(hydroxyphenyl)methane paste epoxy resins (for example, Dow Chemical Co., Ltd., Tuftex-742, XD-9053; Nippon Kayaku Co., Ltd., EPPN-502, etc.). ] and (meth)acrylic acid, and then polybasic carboxylic acid or its anhydride (e.g. maleic acid, phthalic acid,
(tetrahydrophthalic acid, hexahydrophthalic acid, head acid, etc. and anhydrides of these acids, etc.), a reaction product of the epoxy resin and (meth)acrylic acid, and a polybasic carboxylic acid or , into one molecule through a compound in which the anhydride is reacted with a diisocyanate (e.g., tolylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, inphorone diisocyanate, diphenylmethane diisocyanate, etc.). (Meth)acrylates having one hydroxyl group (e.g., hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, trimeterolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate acrylate, tris(hydroxyethyl)in cyanurate di(
(meth)acrylate, etc.).

The acid value of these ethylenically unsaturated group-containing prepolymers preferably ranges from 30 to 160 mgKOH/g, particularly preferably from 45 to 120 mgKOH/g.

The reaction between epoxy resins and (meth)acrylic acid is based on (meth)acrylic acid per chemical equivalent of the epoxy group of the epoxy resin.
The reaction is carried out at a ratio of about 0.8 to 1.5 chemical equivalents of acrylic acid, particularly preferably about 0.9 to 1.1 chemical equivalents. It is preferable to use a solvent and further a catalyst (for example, benzyldimethylamine, triethylamine, penciltrimethylammonium chloride, penciltriethylammonium puromite, triphenylstibine, etc.) to accelerate the reaction. The amount is from 01 to 10% by weight, particularly preferably from 0.3 to 5% by weight, based on the reaction mixture.
It is. In order to prevent polymerization during the reaction, it is preferable to use a polymerization inhibitor (e.g., methoquinone, hydroquinone, phenothiazine, etc.), and the amount used is 0.01 to 1% by weight, especially 0.01 to 1% by weight based on the reaction mixture. Preferably 0.0
It is 5 to 0.5% by weight. Reaction temperature is 60-150℃
, particularly preferably 80 to 120°C.

The reaction between the reaction product of the epoxy resin and (meth)acrylic acid obtained by the above method and the polybasic carboxylic acid or its anhydride (esterification reaction of the hydroxyl group in the epoxy (meth)acrylate) 0.05 to 1.0 of the above acid or its anhydride per 1 chemical equivalent of hydroxyl group relative to the hydroxyl group in the reaction product of resins and (meth)acrylic acid.
0 chemical equivalents are reacted. The reaction temperature is 60-150℃,
Particularly preferred is 80-100'C.

Next, to obtain an adduct of the residual hydroxyl group in the hydroxyl group esterification reaction product in the epoxy (meth)acrylate and the (meth)acrylate having one hydroxyl group per molecule via the diisocyanate. First, for example, the diisocyanates and the (meth)acrylates having one hydroxyl group per molecule are reacted in an equimolar ratio at 30 to 100° C. with heating and stirring for 2 to 12 hours to form a semi-urethane. Synthesize (meth)acrylate.

Next, the obtained half-urethane acrylate is mixed with inocyanate of half-urethane (meth)acrylate in an amount of 0.1 chemical equivalent per chemical equivalent of the remaining hydroxyl group in the esterification reaction product of the hydroxyl group in the epoxy (meth)acrylate. 30S100 in a ratio of equivalent or more, preferably 02 chemical equivalent or more
It can be obtained by reacting 2S at ℃ for 12 hours.

The composition according to the present invention uses a compound (B) represented by the general formula [I]. The compound (B) is copolymerized with the ethylenically unsaturated group-containing prepolymer (A) by irradiation with ultraviolet rays. , further when heated, the compound (-CH20R in BJ
One group is crosslinkable by itself, and is further used as a compound capable of crosslinking with a copolymer produced by ultraviolet irradiation of the ethylenically unsaturated group-containing prepolymer (A) and compound (5). It is advantageously suitable for. Compound CB
) is usually about 0.0% relative to its non-volatile components in the composition.
It is used in an amount of 5 to 30% by weight, preferably 1 to 20% by weight.

Compounds represented by general formula [I] (specific examples include:
■ Acrylic modified alkylated melamine resin, Nika5 Tsuku MX- manufactured by Sanso Chemical Co., Ltd., which can be easily made by hand than on the market.
Examples include MX-301, MX-302, and MX-302.

Next, a photopolymerization initiator (typical examples of Q include benzoin benzyl, benzoin methyl ether, penzoin isopropyl ether, acetophenone, 2.2-dimethoxy-2-phenylacetophenone, 2.2-jetoxy-2- Phenylacetophenone, 1,1-dichloroacetophenone, l-hydroxycyclohexylphenylketone, 2-methyl-1-1"4-(methylthio)phenyl-2-morpholino-propan-1-one, N,
N-dimethylaminoacetophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-te
rt-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, 2.4-dimethylthioxanthone, 2.4-diethylthioxanthone, 2.4-diisopropylthioxanthone, acetophenone dimethyl ketal, benzophenone, methylbenzophenone, Examples include 4,4-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, and Michler's ketone. These can be used alone or in combination of two or more. Furthermore, the photopolymerization initiator (Q is a known and commonly used photosensitizer such as N,N-dimethylaminebenzoic acid ethyl ester, N,N-dimethylaminobenzoic acid inamyl ester, triethanolamine, triethylamine). It can be used alone or in combination of two or more kinds.The preferable range of the amount of the photopolymerization initiator (Q) used is 0.5 parts by weight per 100 parts by weight of the ethylenically unsaturated group-containing prepolymer. The amount is 2 to 30 parts by weight, preferably 2 to 20 parts by weight.Next, as the diluent, a photopolymerizable vinyl monomer and/or an organic solvent can be used.Representative of photopolymerizable vinyl yarn tops Examples include 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, tripropylene glycol diacrylate, N,
N-dimethylacrylamide, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol penta and hexaacrylate, tris-hydroxyethyl isocyanurate tri- and triacrylate, phenoxy acrylate, acrylate of ethylene oxide adduct of bisphenol A, tri- Examples include methylolpropane triethoxy triacrylate and trimethylolpropane triglycidyl ether acrylate. On the other hand, examples of organic solvents include ethyl methyl ketone, cyclohexanone, toluene, xylene, methyl cellosolve, methyl cellosolve, methyl carpitol, butyl carpitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene gelcol mono Examples include ethyl ether, ethyl acetate, butyl acetate, propatool, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. The above-mentioned diluents may be used alone or as a mixture of two or more, and the preferred amount used is 20 to 300 parts by weight per 100 parts by weight of the ethylenically unsaturated group-containing prepolymer.
Parts by weight, preferably 30 to 200 parts by weight.

Furthermore, if necessary, fillers such as barium sulfate, silicon oxide, Merck, clay, and calcium carbonate, coloring pigments such as phthalocyanine blue, phthalocyanine green, titanium oxide, and carbon black, antifoaming agents, adhesion agents, and leveling agents are added. Various additives such as hydroquinone, phenothiazine, and other polymerization inhibitors may be added. Furthermore, reaction products of epoxy resins (e.g., bisphenol-type epoxy resins, novolak-type epoxy resins, etc.) and acrylic acid may be added. It is also possible to use the epoxy acrylate or the epoxy resin together with an epoxy curing agent such as an amine compound, an imidazole compound, a phenol, or a photocationic polymerization catalyst. The irradiation light source for curing the composition of the present invention is low pressure.

Medium pressure, high pressure and extra high pressure mercury lamps, xenon lamps or metal halide lamps are suitable.

The composition of the present invention is particularly useful as a solder resist resin composition, but can also be used as an insulating material, an impregnating material, a surface coating material, a paint, an adhesive, and the like.

When the composition of the present invention is cured and used as a solder resist, the thickness of the cured product is preferably 5 to 50 microns.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

[Example of synthesis of ethylenically unsaturated group-containing prepolymer having a carboxyl group in the molecule]

Synthesis Example 1゜Phenol novolak type epoxy resin (manufactured by Nippon Kayaku ■,
EPPN-201 epoxy equivalent 180) 1800g and acrylic acid 720g1) Riphenyl stibine 26g1
1.25 g of hydroquinone and 1407 g of hifthyl cellosolve acetate were charged, and then reacted at 95°C for 24 hours. Next, 740.6 g of hexahydrophthalic anhydride was charged and reacted at 90°C for 24 hours, resulting in 86 mg KOH/g.
Acid value (excluding butyl cellosolve acetate)
A compound having the following was obtained.

Synthesis Example 2 2180 g of cresol novolac type epoxy resin (Nipponka type: manufactured by Kiki Co., Ltd., EOCN-103 epoxy equivalent weight 218),
Acrylic a 720.6g, triphenyl stibine 26
g1 1.25 g of hydroquinone and 1651 g of butyl cellosolve acetate were charged, and then reacted at 95°C for 24 hours. Next, 925 g of tetrahydrophthalic anhydride was charged and reacted at 90°C for 24 hours, resulting in 94.6 mg KOH.
A compound having an acid value of /g (excluding Bfk Selv Acetate) was obtained.

Examples 1-4. Comparative Example 1 A solder resist resin composition was blended according to the composition shown in Table 1, and the coating was applied to a copper through-hole printed wiring board by screen printing to a film thickness of 20 to 100 μm. After drying for a minute, apply a negative film to the paint film, either directly or without contact. then 5
Ultraviolet rays are irradiated using an Ogi ultra-high pressure mercury lamp, and then 1.
The unirradiated portions of the coating were dissolved and removed with an alkaline aqueous solution such as a 5% NatCOs aqueous solution. After that, 1 in a hot air dryer.
The specimens were cured by heating at 50° C. for 60 minutes, and various performance tests were conducted on each of the specimens obtained. The results are shown in Table 1.

(Developability) Ultraviolet rays were irradiated using a 5KW ultra-high pressure mercury lamp, and then the unirradiated portion was dissolved and removed with a 1.5% Nag COs aqueous solution at 30° C., and the developability was evaluated. The judgment criteria are as follows.

0...Dissolution rate is fast.

×・・・・・・Does not dissolve or dissolves extremely slowly.

(Solder heat resistance) The state of the coating film after being immersed in molten solder at 260° C. for 2 minutes was evaluated. The judgment criteria are as follows.

○・・・・・・No abnormality in the appearance of the paint film.

×・・・・・・・The coating film swells, melts, and peels off.

(Solvent Resistance) After being immersed in methylene chloride at 20° C. for 1 hour, the state and adhesion of the coating film were comprehensively evaluated. The judgment criteria are as follows.

○・・・・・・No abnormality in the appearance of the paint film.

×・・・・・・・・・The paint film swells, blisters, and falls off.

(Adhesion) 100 goblets of 1×III size were cut into the coating film of the specimen, and the adhesion was evaluated after peeling off with cellophane tape.

(Pencil hardness) The highest hardness that does not cause scratches on the film is indicated using a pencil hardness tester according to the test method of JIS K-5400 when a load of 1 kg is applied.

(Acid resistance) In a 10% by weight aqueous hydrochloric acid solution at 20°C for 30 minutes...
...There is no change in the paint film at all.

×・・・・・・・・・The paint film swells and falls off.

(Gold plating resistance) After gold plating was performed for 15 minutes at a current density of IA/dm using Autoronex CI (plating liquid) manufactured by Cellex, a peeling test of the coating film was performed using cellophane tape. The judgment criteria are as follows.

○・・・・・・・・・All (Does not peel off.

x: Part or all of the paint film peeled off.

(Insulation Resistance) According to JISZ-3197, the coating film was left in an atmosphere of 80° C. and 95% RH for 240 hours, and the insulation resistance of the coating film was measured.

Unikaratsuku MX-301: ■Manufactured by Sanso Chemical Co., Ltd.
In the acrylic modified alkylated melamine resin (general formula III) RI=C)Li.

Rz=He 3==3.1)==3)
X-302: @ Sanwa Chemical Co., Ltd., acrylic modified alkylated melamine resin (general formula CI) where R+ = CHx.

Jin = H, a = 5. b=1) KAYARAD DPHA: manufactured by Nippon Kayaku ■, polyfunctional acrylate Q DETX: manufactured by Nippon Kayaku ■, photopolymerization initiator-@EP
A: Manufactured by Nippon Kayaku ■, photosensitizer EPPN-201
: Manufactured by Nippon Kayaku ■, novolac type epoxy resin QSP-170: Manufactured by Asahi Denka ■, photocationic polymerization catalyst Yuboxy acrylate: Phenol novolac type epoxy resin (manufactured by Nippon Kayaku ■, EPPN-201, epoxy equivalent 180) 1800 g 720g of acrylic acid was reacted and diluted with 30% butyl cellosolve acetate.

(Effects of the invention) The resin composition of the present invention and its cured product can be developed with a dilute alkali aqueous solution, and have excellent heat resistance, adhesion, solvent resistance, acid resistance,
It has excellent plating resistance, moisture resistance, electrical properties, etc., and is suitable for solder resist resin compositions.

Claims (1)

[Claims] 1) Ethylenically unsaturated group-containing prepolymer (A) having carboxyl groups in the molecule and general formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 is lower alkyl The group R_2 is H or C
It is H_3. a+b is 6, a is a number from 1 to 5, and b is a number from 1 to 5. ) A photosensitive thermosetting resin composition comprising a compound (B) represented by (B), a photopolymerization initiator (C), and a photopolymerizable vinyl monomer and/or an organic solvent as a diluent (D). 2) Ethylenically unsaturated group-containing prepolymer (A) having a carboxyl group in the molecule and general formula [I] ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1 is a lower alkyl group, R_2 is H or CH_3. a+b is 6, a is a number from 1 to 5, and b is a number from 1 to 5.)
), a photopolymerization initiator (C), and a photopolymerizable vinyl monomer and/or an organic solvent as a diluent (D). 3) Cured product of the resin composition according to item 1 or 2