JP2020147624A - Curable composition - Google Patents

Abstract

To provide a curable composition that is prepared by mixing two liquids and contains triglycidyl isocyanurate, which has improved agitation property and printability.SOLUTION: A curable composition is prepared by mixing a first liquid containing (A) an alkali-soluble resin and (B) a photopolymerization initiator and a second liquid that contains (C) triglycidyl isocyanurate and has viscosity at 25°C and 5 rpm of 10-100 dPa s, and has viscosity at 25°C and 5 rpm of 100-500 dPa s, in which (E) a photopolymerizable polyfunctional monomer and (F) an inorganic filler are contained in either or both of the first liquid and the second liquid before mixing.SELECTED DRAWING: None

Description

The present invention relates to an alkali-developable curable composition, and more particularly to an alkali-developable curable composition containing triglycidyl isocyanurate.

Conventionally, in the solder resist of consumer printed circuit boards and industrial printed wiring boards, from the viewpoint of high accuracy and high density, an image is formed by developing after irradiation with ultraviolet rays, and finish curing by heat and / or light irradiation ( A liquid-developing solder resist that undergoes main curing) is used.

Among the liquid development type solder resists, the alkali development type photo solder resist that uses an alkaline aqueous solution as a developing solution has become the mainstream in consideration of environmental problems.

When an epoxy resin is blended as a thermosetting agent with an alkali-developed photosolder resist, a main agent containing a carboxyl group-containing resin that enables alkaline development is used to prevent the curing reaction from proceeding during storage. , It is often used as a so-called two-component photosensitive thermosetting resin composition, which is stored separately from a curing agent containing an epoxy resin and mixed at the time of use.

Printed circuit boards manufactured using alkaline-developed photo solder resists are used, for example, in personal computers, mobile terminals, LED lighting, IC evaluation boards, etc., but are subject to high-temperature environments such as in-vehicle applications and repeated vibrations. Under exposure conditions, the development of photosolder resists with higher temperature resistance and rigidity is expected.

Patent Document 1 provides a solder resist ink resin composition having a long pot life and excellent workability, and the cured film having excellent solder heat resistance, adhesion to a printed wiring substrate, and chemical resistance. A photopolymerizable unsaturated group-containing polycarboxylic acid resin (A) obtained by reacting a novolak type epoxy resin, an unsaturated monocarboxylic acid, and an anhydride of an organic polybasic acid, a photopolymerization initiator. Disclosed is a solder resist ink resin composition containing (B), tris (2,3-epoxypropyl) isocyanurate (C) and melamine cyanurate (D).

Japanese Unexamined Patent Publication No. 7-41716

According to the solder resist ink resin composition described in Patent Document 1, the obtained cured product is excellent in solder heat resistance, adhesion to a printed wiring board, and chemical resistance.

However, when triglycidyl isocyanurate (tris (2,3-epoxypropyl) isocyanurate) is added, heat resistance and rigidity are improved, but coarse particles increase in the composition, which affects printability on a screen or the like. Therefore, it is necessary to perform filtration with fine precision, and it takes time for the filtration.

Further, in the case of a two-component photosensitive resin composition, where mixing at an accurate mixing ratio is required, triglycidyl isocyanurate has poor compatibility with the carboxyl group-containing resin, and foreign matter is generated due to insufficient stirring. There was a problem that it was easy.

The present invention has been made in view of the above problems, and an object of the present invention is to improve stirrability and printability in a curable composition containing triglycidyl isocyanurate, which is prepared by mixing two liquids. The purpose is to provide a curable composition.

The present inventors have made diligent studies to achieve the above object. As a result, when triglycidyl isocyanurate is blended into the curable composition, the viscosity of the second liquid and the viscosity of the curable composition after mixing are set within a predetermined range, and the phases of the first liquid and the second liquid are set. They have found that the solubility is improved and the stirring property and printability of the curable composition are improved, and have completed the present invention.

That is, the above object of the present invention is
(A) Alkali-soluble resin and
(B) Photopolymerization initiator and
1st solution containing
(C) A second solution containing trichloroisocyanuric acid and having a viscosity at 25 ° C. and 5 rpm in the range of 10 to 100 dPa · s.
A curable resin composition having a viscosity at 25 ° C. and 5 rpm in the range of 100 to 500 dPa · s, which is a mixture of the above.
Curability characterized in that (E) a photopolymerizable polyfunctional monomer and (F) an inorganic filler are contained in either or both of the first liquid and the second liquid before mixing, respectively. It has been found that this is achieved with the composition.

In the curable composition of the present invention, the mixing ratio of the first liquid and the second liquid is preferably 6: 4 to 9: 1.

Further, it is preferable that the (E) photopolymerizable polyfunctional monomer contains an isocyanurate ring-containing compound containing an ethylenically unsaturated group.

Further, it is preferable to contain (D) epoxy resin.

Further, the curable composition of the present invention is preferably used as an ink for screen printing.

According to the present invention, even if trichloroisocyanuric acid (C) is contained, the viscosity of the second liquid and the viscosity of the curable composition after mixing are set within a predetermined range to obtain the first liquid and the second liquid. The compatibility of the above is improved, the stirring property is improved, and the continuous printability in screen printing or the like can be improved. Further, when the curable composition contains (C) trichloroisocyanuric acid triglycidyl, the heat resistance and rigidity of the obtained cured product are improved. Therefore, it can be used as a photosolder resist for a printed circuit board incorporated in an in-vehicle terminal that requires high heat resistance and rigidity.

<Curable composition>
The curable composition of the present invention is
(A) Alkali-soluble resin and
(B) Photopolymerization initiator and
1st solution containing
(C) A second solution containing trichloroisocyanuric acid and having a viscosity at 25 ° C. and 5 rpm in the range of 10 to 100 dPa · s.
A curable composition having a viscosity at 25 ° C. and 5 rpm in the range of 100 to 500 dPa · s, which is a mixture of the above.
The (E) photopolymerizable polyfunctional monomer and the (F) inorganic filler are contained in either or both of the first liquid and the second liquid before mixing, respectively.

[(A) Alkali-soluble resin]
The alkali-soluble resin is a resin that enables the curable composition to be dissolved in an alkaline developer, that is, developed with an alkali, and is contained in the first liquid.

As the alkali-soluble resin, it is preferable to use a carboxyl group-containing resin or a phenol resin. In particular, it is more preferable to use a carboxyl group-containing resin from the viewpoint of developability.

As the carboxyl group-containing resin, various conventionally known carboxyl group-containing resins having a carboxyl group in the molecule and not having an ethylenically unsaturated group (non-photosensitive) or having this (photosensitive) Can be used.

In the present invention, the ethylenically unsaturated group is a substituent having an ethylenically unsaturated bond, and examples thereof include a vinyl group and a (meth) acryloyl group. From the viewpoint of reactivity, a (meth) acryloyl group is used. Is preferable. Here, the (meth) acryloyl group is a general term for an acryloyl group and a meta-acryloyl group.

Specific examples of the carboxyl group-containing resin having no ethylenically unsaturated group include the following compounds (either oligomer or polymer).

(1) Dialcohol compounds, polycarbonate-based polyols, which contain diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates, and carboxyl groups such as dimethylolpropionic acid and dimethylolbutanoic acid. A carboxyl group-containing urethane resin obtained by a double addition reaction of a diol compound such as a polyether polyol, a polyester polyol, a polyolefin polyol, a bisphenol A alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(2) A carboxyl group-containing urethane resin obtained by a double addition reaction of a diisocyanate and a carboxyl group-containing dialcohol compound.

(3) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, or isobutylene.

(4) A dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid is reacted with a bifunctional epoxy resin or a bifunctional oxetane resin, and the generated hydroxyl group is subjected to phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, or the like. A carboxyl group-containing polyester resin to which a dibasic acid anhydride is added.

(5) A carboxyl group-containing resin obtained by opening an epoxy resin or an oxetane resin and reacting the generated hydroxyl group with a polybasic anhydride.

(6) A polybasic acid anhydride is added to a reaction product such as a polyalcohol resin obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule, that is, a polyphenol compound, with an alkylene oxide such as ethylene oxide or propylene oxide. A carboxyl group-containing resin obtained by reacting with.

In addition, specific examples of the carboxyl group-containing resin having an ethylenically unsaturated group include the following compounds (either oligomer or polymer). The ethylenically unsaturated bond in the carboxyl group-containing resin is preferably derived from acrylic acid, methacrylic acid, or a derivative thereof.

(7) Dialcohol compounds, polycarbonate-based polyols, which contain diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates, and carboxyl groups such as dimethylolpropionic acid and dimethylolbutanoic acid. Containing carboxyl group by multiple addition reaction of diol compound such as polyether polyol, polyester polyol, polyolefin polyol, acrylic polyol, bisphenol A alkylene oxide adduct diol, compound having phenolic hydroxyl group and alcoholic hydroxyl group Photosensitive urethane resin.

(8) Diisocyanate and bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin ( Meta) A carboxyl group-containing photosensitive urethane resin obtained by a double addition reaction of an acrylate or a partially acid anhydride modified product thereof and a carboxyl group-containing dialcohol compound.

(9) During the synthesis of the resin of (7) or (8) described above, a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule such as hydroxyalkyl (meth) acrylate is added, and the terminal is added. (Meta) Acryloylated carboxyl group-containing photosensitive urethane resin.

(10) During the synthesis of the resin according to (8) or (9) above, one isocyanate group and one or more (meth) acryloyl groups in the molecule, such as an isophorone diisocyanate and pentaerythritol triacrylate isomorphic reaction product. A carboxyl group-containing photosensitive urethane resin that is terminally (meth) acrylicized by adding a compound having.

(11) A carboxyl group-containing photosensitive resin obtained by reacting a bifunctional or higher polyfunctional (solid) epoxy resin with (meth) acrylic acid and adding a dibasic acid anhydride to a hydroxyl group existing in a side chain.

(12) Carboxylic acid obtained by reacting (meth) acrylic acid with a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl groups of a bifunctional (solid) epoxy resin with epichlorohydrin, and adding a dibasic acid anhydride to the generated hydroxyl groups. Group-containing photosensitive resin.

(13) A dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid is reacted with a bifunctional oxetane resin, and the generated primary hydroxyl group is subjected to two bases such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. A carboxyl group-containing polyester photosensitive resin to which an acid anhydride is added.

(14) A (meth) acrylic acid is added to a reaction product such as a polyalcohol resin obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule, that is, a polyphenol compound, with an alkylene oxide such as ethylene oxide or propylene oxide. A carboxyl group-containing photosensitive resin obtained by reacting an unsaturated group-containing monocarboxylic acid such as the above with a reaction product obtained by further reacting a polybasic acid anhydride.

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

(16) A carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth) acryloyl groups in one molecule to the above-mentioned resins (7) to (15).

As these photosensitive carboxyl group-containing resins, those other than those described in (7) to (16) can be used, and one type may be used alone or a plurality of types may be mixed and used. Among the carboxyl group-containing resins, a resin having an aromatic ring is particularly preferable.

The above-mentioned carboxyl group-containing resin can be said to be as follows regardless of whether it is photosensitive or non-photosensitive. That is, since the backbone polymer has a large number of carboxyl groups in the side chain, it can be developed with a dilute alkaline aqueous solution.

The acid value of the carboxyl group-containing resin is preferably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. When the acid value of the carboxyl group-containing resin is within such a range, alkaline development becomes easy, dissolution of the exposed part by the developer is suppressed, the line is not thinned more than necessary, and there is no dissolution peeling by the developer. It is possible to draw a normal pattern.

The weight average molecular weight of the above-mentioned carboxyl group-containing resin varies depending on the resin skeleton, but is generally preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. When the weight average molecular weight is within such a range, the tack-free performance is excellent, the moisture resistance of the coating film after exposure is good, and the resolution, developability, and storage stability are excellent.

The blending amount of such a carboxyl group-containing resin is appropriately in the range of 20 to 80% by mass, preferably 30 to 70% by mass in the curable composition (solid content). When the blending amount of the carboxyl group-containing resin is within such a range, the strength of the coating film does not decrease, and the thickening and the workability do not decrease.

Further, in the present invention, as the alkali-soluble resin (A), either a photosensitive carboxyl group-containing resin or a non-photosensitive carboxyl group-containing resin may be used, or these may be mixed and used. It is possible.

Examples of the phenol resin include compounds having a phenolic hydroxyl group, for example, a compound having a biphenyl skeleton and / or a phenylene skeleton, or a phenolic hydroxyl group-containing compound, for example, phenol, orthocresol, paracresol, metacresol, 2 , 3-Xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, catechol, cresolsinol, hydroquinone, methylhydroquinone, 2,6-dimethylhydroquinone , Trimethylhydroquinone, pyrogallol, fluoroxylenol and the like, and phenolic resins having various skeletons may be used.

For example, phenol novolac resin, alkylphenol volac resin, bisphenol A novolak resin, dicyclopentadiene type phenol resin, Xyloc type phenol resin, terpene modified phenol resin, polyvinylphenols, bisphenol F, bisphenol S type phenol resin, poly-p- Known and commonly used phenolic resins such as hydroxystyrene, a condensate of naphthol and aldehydes, and a condensate of dihydroxynaphthalene and aldehydes can be used.

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

Commercially available products of such phenolic resins include HF-1M (manufactured by Meiwa Kasei Co., Ltd.), Phenolite TD-2090, Phenolite TD-2131 (manufactured by DIC Corporation), Vesmol CZ-256-A (manufactured by DIC Corporation), and Cyonol BRG. -555, Cyonor BRG-556 (manufactured by Aica Kogyo Co., Ltd.), CGR-951 (manufactured by Maruzen Petroleum Co., Ltd.), or polyvinylphenols CST70, CST90, S-1P, S-2P (manufactured by Maruzen Petroleum Co., Ltd.), etc. Can be done. These phenolic resins can be used alone or in combination of two or more.

[(B) Photopolymerization Initiator]
(B) The photopolymerization initiator is added to the first liquid in order to polymerize the (meth) acrylate by irradiation with energy rays.

(B) The photopolymerization initiator is, for example, benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin alkyl ethers; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-. Acetphenones such as diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -On, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] Aminoalkylphenones such as -1-butanone; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-terriary butyl anthraquinone, 1-chloroanthraquinone; 2,4-dimethylthioxanthone , 2,4-Diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone and other thioxanthones; acetophenone dimethyl ketal, benzyl dimethyl ketal and other ketals; 4,4'-bis (diethylamino) benzophenone and other benzophenones (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, Phosphine oxides such as ethyl-2,4,6-trimethylbenzoylphenylphosphinate; 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, Oxim esters such as 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime); various peroxides, titanosen-based initiators, etc. Can be mentioned. These are photosensitized like tertiary amines such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine and the like. It may be used in combination with an agent or the like. These photopolymerization initiators can be used alone or in combination of two or more.

The amount of the (B) photopolymerization initiator compounded in the curable composition of the present invention is in the range of 0.01 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass (solid content) of the (A) alkali-soluble resin. , Preferably blended in the range of 0.5 to 15 parts by mass or less.

[(C) Trichloroisocyanuric acid]
(C) Trichloroisocyanuric acid is a compound added to thermoset the curable composition of the present invention to improve the heat resistance and rigidity of the cured product, and is added to the second liquid.

Then, (C) triglycidyl isocyanurate contains an epoxy group, and the isocyanurate ring is incorporated into the polymer of the cured product by a thermosetting reaction.

Examples of commercially available products of triglycidyl isocyanurate (C) include TEPIC-S, TEPIC-L, and TEPIC-HP (manufactured by Nissan Chemical Industries, Ltd.).

In the curable composition of the present invention, the amount of (C) triglycidyl isocyanurate is 10 parts by mass or more and 50 parts by mass or less, preferably 10 parts by mass, based on 100 parts by mass (solid content) of the (A) alkali-soluble resin. It is blended in the range of parts or more and 35 parts by mass or less. When the blending amount of triglycidyl isocyanurate (C) is within such a range, a cured product having excellent heat resistance, electrical characteristics, and flexibility can be obtained.

[(D) Epoxy resin]
The epoxy resin (D) (excluding (C) trichloroisocyanuric acid triglycidyl) is a compound added for thermosetting the curable composition of the present invention, and may be further added to the second liquid. ..

As the (D) epoxy resin (excluding (C) triglycidyl isocyanurate), a known and commonly used polyfunctional epoxy resin having at least two epoxy groups in one molecule can be used. Examples of the epoxy resin (excluding (C) triglycidyl isocyanurate) include jER828, jER834, jER1001, jER1004 manufactured by Mitsubishi Chemical Corporation, EPICLON840, EPICLON850, EPICLON850-S, EPICLON1050, EPICLON2055, manufactured by DIC Corporation. Epototo YD-011, YD-013, YD-127, YD-128 manufactured by Toto Kasei Co., Ltd., and D.D. E. R. 317, D.I. E. R. 331, D. E. R. 661, D.I. E. R. 664, Sumitomo Chemical Co., Ltd. Sumi-Epoxy ESA-011, ESA-014, ELA-115, ELA-128, etc. (all trade names) bisphenol A type epoxy resin; Mitsubishi Chemical Co., Ltd. jER YL903, DIC Corporation EPICLON152, EPICLON165, Epototo YDB-400, YDB-500 manufactured by Toto Kasei Co., Ltd., D.D. E. R. 542, Sumitomo Chemical's Sumi-Epoxy ESB-400, ESB-700, etc. (all trade names) brominated epoxy resins; Mitsubishi Chemical's jER152, jER154, Dow Chemical's D.D. E. N. 431, D.I. E. N. 438, EPICLON N-730 manufactured by DIC, EPICLON N-770, EPICLON N-865, Epototo YDCN-701, YDCN-704 manufactured by Toto Kasei Co., Ltd. -1020, EOCN-104S, RE-306, NC-3000, Sumitomo Chemical Co., Ltd. Sumi-Epoxy ESCN-195X, ESCN-220, Nippon Steel Chemical Co., Ltd. YDCN-700-2, YDCN-700-3 , YDCN-700-5, YDCN-700-7, YDCN-700-10, YDCN-704 YDCN-704A, EPICLON N-680, EPICLON N-690, EPICLON N-695 manufactured by DIC (all trade names) Novolak type epoxy resin such as DIC; EPICLON 830 manufactured by DIC, jER807 manufactured by Mitsubishi Chemical Co., Ltd., Epototo YDF-170, YDF-175, YDF-2004 manufactured by Toto Kasei Co., Ltd., etc. (all trade names) bisphenol F type epoxy resin; Hydrophobic bisphenol A type epoxy resin such as Epototo ST-2004, ST-2007, ST-3000 (trade name) manufactured by Toto Kasei Co., Ltd., YX8034 manufactured by Mitsubishi Chemical Co., Ltd .; jER604 manufactured by Mitsubishi Chemical Co., Ltd., manufactured by Toto Kasei Co., Ltd. Epototo YH-434, Sumie Epoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd. (both trade names) glycidylamine type epoxy resin; Hidant-in type epoxy resin; Celoxide 2021 etc. manufactured by Daicel Chemical Industry Co., Ltd. (both trade names) ) Alicyclic epoxy resin; YL-933 manufactured by Mitsubishi Chemical Co., Ltd., EPPN-501, EPPN-502 manufactured by Nippon Kayaku Co., Ltd., etc. (all trade names) trihydroxyphenylmethane type epoxy resin; manufactured by Mitsubishi Chemical Co., Ltd. YL-6056, YX-4000, YL-6121 (all trade names) and other bixilenol type or biphenol type epoxy resins or mixtures thereof; EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by ADEKA, DIC Bisphenol S type epoxy resin such as EXA-1514 (trade name) manufactured by Mitsubishi Chemical Co., Ltd .; Bisphenol A novolac type epoxy resin such as jER157S (trade name) manufactured by Mitsubishi Chemical Co., Ltd .; jER YL-931 etc. manufactured by Mitsubishi Chemical Co., Ltd. Tetraphenylol ethane type epoxy resin (trade name); Diglycidyl phthalate resin such as Blemmer DGT manufactured by Nippon Oil & Fats Co., Ltd .; ZX-1063 manufactured by Toto Kasei Co., Ltd. Traglycidyl xylenoyl ethane resin; Naphthalene group-containing epoxy resin such as ESN-190, ESN-360 manufactured by Nippon Steel Chemical Co., Ltd., HP-4032, EXA-4750, EXA-4700 manufactured by DIC Co., Ltd .; HP-7200 manufactured by DIC Co., Ltd. , HP-7200H and other epoxy resins having a dicyclopentadiene skeleton; glycidyl methacrylate copolymerized epoxy resins such as CP-50S and CP-50M manufactured by Nippon Oil & Fats Co., Ltd .; and cyclohexyl maleimide and glycidyl methacrylate copolymer epoxy resins; Examples thereof include, but are not limited to, CTBN-modified epoxy resins (for example, YR-102 and YR-450 manufactured by Toto Kasei Co., Ltd.).

When (D) epoxy resin (excluding (C) triglycidyl isocyanurate) is blended, it is 0.8 epoxy equivalent or more and 2.0 epoxy equivalent or less with respect to the carboxylic acid equivalent of (A) alkali-soluble resin. Formulated in quantity. Here, the carboxylic acid equivalent represents the weight of the (A) alkali-soluble resin required to obtain 1 mol of the carboxyl group, and the unit is g / mol. The epoxy equivalent represents the weight of the (D) epoxy resin required to obtain 1 mol of epoxy groups, and the unit is g / mol. The mass of the (D) epoxy resin is 0.8 epoxy equivalent to 2.0 epoxy equivalent with respect to the carboxylic acid equivalent of the (A) alkali-soluble resin. When the epoxy equivalent is within such a range, a cured product having excellent heat resistance, electrical characteristics, and crack resistance can be obtained.

[(E) Photopolymerizable polyfunctional monomer]
The (E) photopolymerizable polyfunctional monomer is a compound having two or more ethylenically unsaturated groups in one molecule, and ((A) when the alkali-soluble resin contains an ethylenically unsaturated group) ,) Helps photocuring of (A) alkali-soluble resin by irradiation with active energy rays, photocures the curable composition, and the curable composition after mixing the viscosity of the second liquid and the first and second liquids. It is used to adjust the viscosity of ethylene in a decreasing direction.

Examples of the compound used as the (E) photopolymerizable polyfunctional monomer include commonly known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, and epoxy (meth). ) Acrylate and the like can be mentioned. Specifically, polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanurate, or ethyleoxyside adducts, propylene oxide adducts, or ε-caprolactone adducts thereof, etc. Polyvalent acrylates; phenoxy acrylates, bisphenol A diacrylates, and polyvalent acrylates such as ethylene oxide adducts or propylene oxide adducts of these phenols; glycerin diglycidyl ether, glycerin triglycidyl ether, trimethyl propantri. Polyvalent acrylates of glycidyl ethers such as glycidyl ethers and triglycidyl isocyanurates; not limited to the above, polyols such as polyether polyols, polycarbonate diols, hydroxyl group terminal polybutadienes, polyester polyols are directly acrylated, or urethanes are made through diisocyanates. Examples thereof include acrylated acrylates and melamine acrylates, and at least one of each methacrylate corresponding to the acrylate.

In the present invention, in order to further improve the heat resistance, it is preferable to use an isocyanurate ring-containing compound containing an ethylenically unsaturated group as the (E) photopolymerizable polyfunctional monomer. The isocyanurate ring-containing compound containing an ethylenically unsaturated group contains at least two ethylenically unsaturated groups in the molecule from the viewpoint of improving heat resistance and rigidity. The ethylenically unsaturated group is preferably in the range of 3 to 6.

Further, the isocyanurate ring-containing compound containing an ethylenically unsaturated group may be alkylene oxide-modified or lactone-modified.

Examples of the isocyanurate ring-containing compound containing an alkylene oxide-modified ethylenically unsaturated group include an alkylene oxide adduct of an acrylate of isocyanuric acid.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, and butylene oxide, and it is preferable that the alkylene oxide is modified with at least one of ethylene oxide and propylene oxide.

The isocyanurate ring-containing compound containing a lactone-modified ethylenically unsaturated group is obtained by ring-opening polymerization of lactone with an acrylate of isocyanuric acid.

As the lactone, for example, a lactone having a 5- to 8-membered ring can be preferably used.

Commercially available products of isocyanurate ring-containing compounds containing ethylenically unsaturated groups include isocyanuric acid EO-modified diacrylate (Aronix (registered trademark) M-215: manufactured by Toagosei Co., Ltd.) and ethoxylated isocyanurate triacrylate (A-9300). : Shin-Nakamura Chemical Industry Co., Ltd.), ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate (A-9300-1CL: New Nakamura Chemical Industry Co., Ltd.).

Further, the photopolymerizable polyfunctional monomer (E) is a photopolymerizable polyfunctional monomer having a viscosity of 10 dPa · s or less at 25 ° C. and 5 rpm from the viewpoint of lowering the viscosity of the second liquid and the viscosity of the curable composition. Is preferable.

The blending amount of the (E) photopolymerizable polyfunctional monomer is in the range of 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass (solid content) of the (A) alkali-soluble resin in the curable composition of the present invention. , Preferably blended in the range of 10 parts by mass or more and 35 parts by mass or less. When the blending amount of the photopolymerizable polyfunctional monomer (E) is within such a range, a cured product with less undercut and halation can be obtained.

[(F) Inorganic filler]
(F) The inorganic filler enhances the physical strength of the cured product of the curable composition of the present invention, and also determines the viscosity of the second liquid and the viscosity of the curable composition after mixing the first liquid and the second liquid. Is used to adjust in the direction of increasing.

Examples of the inorganic filler (F) include silica, barium sulfate, barium titanate, Neuburg silica soil, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, titanium oxide, aluminum hydroxide, silicon nitride, and aluminum nitride. Can be mentioned. Examples of commercially available inorganic fillers include talc (LMP-100: manufactured by Fuji Tarku Kogyo Co., Ltd.), silica filler (Imsil® A-8: manufactured by UNIMIN), and aluminum hydroxide (B). -30: Rutile type titanium oxide (CR-58: manufactured by Ishihara Sangyo Co., Ltd.), barium sulfate (B-30: manufactured by Sakai Chemical Industry Co., Ltd.) and the like.

The blending amount of the inorganic filler (F) is preferably in the range of 30 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass (solid content) of the (A) alkali-soluble resin in the curable composition of the present invention. It is blended in the range of 50 parts by mass or more and 110 parts by mass or less. When the blending amount of the inorganic filler (F) is within such a range, the cured product does not become brittle and the effect of improving the physical strength can be obtained.

The viscosity of the second liquid and the viscosity of the curable composition after mixing the first liquid and the second liquid are specifically contained in either one or both of the first liquid and the second liquid (respectively). It can be adjusted by the amount of E) photopolymerizable polyfunctional monomer and (F) inorganic filler. The amounts of the (E) photopolymerizable polyfunctional monomer and (F) inorganic filler contained in either or both of the first liquid and the second liquid are contained in the curable composition of the present invention (E). ) There is no particular limitation as long as the blending amount of the photopolymerizable polyfunctional monomer and the (F) inorganic filler is within the range.

The viscosity of the second liquid to be adjusted is in the range of 10 to 100 dPa · s at 25 ° C. and 5 rpm, preferably in the range of 50 to 70 dPa · s. The viscosity of the curable composition to be adjusted is in the range of 100 to 500 dPa · s, preferably in the range of 100 to 200 dPa · s at 25 ° C. and 5 rpm.

Further, the curable composition of the present invention may contain an organic solvent for the purpose of preparing the composition, adjusting the viscosity when applied to the substrate, and the like. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol and propylene glycol monomethyl ether. , Dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether and other glycol ethers; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbi Esters such as tall acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, and solvent naphtha are known. Conventional organic solvents can be used. These organic solvents may be used alone or in combination of two or more.

The amount of the organic solvent blended is in the range of 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass (solid content) of the (A) alkali-soluble resin.

The viscosity of the second liquid and the viscosity of the curable composition after mixing the first liquid and the second liquid are specifically, when an organic solvent is contained, either one of the first liquid and the second liquid. Alternatively, it can be adjusted by the amount of (E) photopolymerizable polyfunctional monomer, (F) inorganic filler and organic solvent contained in both of them. The amounts of (E) photopolymerizable polyfunctional monomer, (F) inorganic filler and organic solvent contained in either one or both of the first liquid and the second liquid are included in the curable composition of the present invention. There is no particular limitation as long as it is within the range of the blending amounts of the (E) photopolymerizable polyfunctional monomer and the (F) inorganic filler and the blending amount of the organic solvent.

[Other ingredients]
The curable composition of the present invention may further contain a known and commonly used coloring pigment such as phthalocyanine blue, phthalocyanine green, and carbon black, if necessary.

In addition, various additives such as antifoaming agents, adhesion imparting agents or leveling agents, known and commonly used polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, pyrogallol, tertiary butylcatechol, phenothiazine, coupling agents, dispersants, etc. Additives such as flame retardants can be included.

The curable composition of the present invention is obtained by mixing and stirring the first liquid and the second liquid at a mixing ratio (mass ratio) of 6: 4 to 9: 1, preferably 7: 3 to 8: 2. .. The first liquid and the second liquid, which are weighed respectively, may be mixed and stirred in one container, or a known two-liquid mixing / discharging device may be used. The two-component mixing / discharging device is commercially available, for example, from Sanshu Kogyo Co., Ltd., Lexie Co., Ltd., Tomita Engineering Co., Ltd., Hyojin Equipment Co., Ltd., and the like.

The curable composition of the present invention is printed on a substrate by a screen printing method. The viscosity applicable to screen printing is, for example, a viscosity at 25 ° C. and 5 rpm in the range of 100 to 500 dPa · s, preferably in the range of 150 to 350 dPa · s.

In addition to pre-circuit-formed printed wiring boards and flexible printed wiring boards, the base material is paper + phenol resin, paper + epoxy resin, paper + glass cloth + epoxy resin, glass non-woven fabric + epoxy resin, glass woven cloth + epoxy resin. , Copper-clad laminate such as glass fiber + polyimide resin, polyimide film, PET film, glass substrate, ceramic substrate, wafer plate and the like.

Drying after application of the curable composition of the present invention can be carried out using a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection oven or the like.

By heating the curable composition of the present invention to a temperature of, for example, about 140 to 180 ° C. and thermosetting it, a cured coating film having excellent heat resistance and rigidity can be formed.

The coating film obtained after applying the curable composition of the present invention and volatilizing and drying the solvent is exposed (irradiated with active energy rays) to expose an exposed portion (a portion irradiated with active energy rays). Hardens. Further, by the contact method (or non-contact method), the unexposed portion is selectively exposed to active energy rays or the pattern is directly exposed by a laser direct exposure machine through a photomask in which a pattern is formed, and the unexposed portion is exposed to a dilute alkaline aqueous solution (for example, 0.3). A resist pattern is formed by developing with (~ 3 wt% sodium carbonate aqueous solution).

The exposure machine used for the above-mentioned active energy ray irradiation may be a device equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., and irradiates ultraviolet rays in the range of 350 to 450 nm. Further, a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser based on CAD data from a computer) can also be used. The amount of exposure for image formation varies depending on the film thickness and the like, but is generally in the range of 100 to 1000 mJ / cm ² , preferably 200 to 800 mJ / cm ² .

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

Since the curable composition of the present invention is excellent in heat resistance, rigidity, adhesion to a substrate, and insulating property, it can be applied to various uses, and the application target is not particularly limited. For example, it can be used for making etching resists, solder resists, marking resists, etc. for printed wiring boards. Among them, solder resists that require high heat resistance, especially in-vehicle terminals that require high rigidity and heat resistance. It can be suitably used as a solder resist for a printed circuit board incorporated in.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In the following, unless otherwise specified, "parts" shall mean parts by mass.

((A) Synthesis of alkali-soluble resin)
Cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-104S, epoxy equivalent 220 g / eq) 220 parts (1 equivalent), carbitol acetate 140.1 parts, and solvent naphtha 60.3 parts were charged into a flask and 90 parts. Heated and stirred at ° C to dissolve. The obtained solution was once cooled to 60 ° C., 72 parts (1 mol) of acrylic acid, 0.5 part of methylhydroquinone and 2 parts of triphenylphosphine were added, heated to 100 ° C., reacted for about 12 hours, and the acid value was increased. Obtained a reaction product of 0.2 mgKOH / g. 80.6 parts (0.53 mol) of tetrahydrophthalic anhydride was added thereto, and the mixture was heated to 90 ° C. and reacted for about 6 hours. A resin solution having a solid acid value of 85 mgKOH / g and a solid content concentration of 64.9%. ((A) Alkali-soluble resin) was obtained.

<1. Preparation of curable compositions of Examples 1-3 and Comparative Examples 1-2>
Each material shown in Table 1 is mixed and premixed with a stirrer, then kneaded with a 3-roll mill to prepare the first liquid, and each material also shown in Table 1 is mixed and premixed with a stirrer. Then, the second liquid was prepared by kneading with a three-roll mill. Then, the first liquid and the second liquid were mixed and stirred to prepare a curable composition. In Table 1, for varnish A, the mass of the resin solution containing the solvent is shown.

* 1: 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (Omnirad 907: manufactured by IGM Resins BV)
* 2: 2,4-diethylthioxanthone (KAYACURE DETX-S: manufactured by Nippon Kayaku Co., Ltd.)
* 3: 4,4'-bis (diethylamino) benzophenone (EAB: manufactured by Hodogaya Chemical Co., Ltd.)
* 4: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H: manufactured by IGM Resins BV)
* 5: Dipentaerythritol hexaacrylate (DPHA: manufactured by Daicel Ornex)
* 6: Trimethylolpropane EO-modified (n≈1) triacrylate (M-350: manufactured by Toagosei Co., Ltd.)
* 7: Talc (LMP-100: manufactured by Fuji Talc Industry Co., Ltd.)
* 8: Silica filler (Imsil® A-8: manufactured by UNIMIN)
* 9: Barium sulfate (B-30: manufactured by Sakai Chemical Industry Co., Ltd.)
* 10: Green pigment (FASTOGEN GREEN S: manufactured by DIC Corporation)
* 11: Diethylene glycol monoethyl ether acetate (D0500: manufactured by Tokyo Chemical Industry Co., Ltd.)
* 12: High boiling point aromatic solvent (T-SOL (registered trademark) 150: manufactured by JXTG Energy Co., Ltd.)
* 13: Trichloroisocyanuric acid (TEPIC-S: manufactured by Nissan Chemical Industries, Ltd.)
* 14: Cresol novolac type polyfunctional epoxy resin Epoxy equivalent 209-219 (g / eq) (EPICLON N-695: manufactured by DIC Corporation)
* 15: Phenolic novolac type epoxy resin (RE-306: manufactured by Nippon Kayaku Co., Ltd.)
* 16: Bisphenol A type epoxy resin (JER (registered trademark) -834: manufactured by Mitsubishi Chemical Corporation)
* 17: Trichloroisocyanuric acid ethoxylated (A-9300: manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)
* 18: The viscosity was measured at 5 rpm (rpm) at 25 ° C. using a rotary viscometer (Toki Sangyo VISCOMETER TV-33 cone plate type). The same applies to the viscosity of the curable composition. The viscosity (unit: dPa · s) immediately after adjustment was measured for both the second liquid (hardener) and the curable composition.

<2. Evaluation ＞
2-1. Solder heat resistance 2-1-1. Preparation of test substrate Using a FR-4 copper-clad laminate (copper thickness 70 μm) with a size of 100 mm × 150 mm and a thickness of 1.6 mm, a pattern with a width of 1 mm, a length of 100 mm, and a space of 5 mm was obtained by an etching method. Was prepared and used as a test substrate.

2-1-2. Preparation of test piece The curable compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were screen-printed on a FR-4 copper-clad laminate (copper thickness 70 μm) having a size of 100 mm × 150 mm and a thickness of 1.6 mm. It was printed on the entire surface using a 100 mesh polyester bias plate by the method, and dried in a hot air circulation type drying oven at 80 ° C. for 30 minutes. Next, using a negative pattern that can cover all lines, exposure was performed with an exposure machine for printed wiring boards HMW-680GW (manufactured by ORC Manufacturing Co., Ltd.) with an integrated light amount of 700 mJ / cm ² , and 1% at 30 ° C. Using an aqueous sodium carbonate developer as a developing solution, the test piece was developed in a developing machine for a printed wiring board for 60 seconds, and then heat-cured in a hot air circulation drying furnace for 60 minutes at 150 ° C. to prepare a test piece.

2-1-3. Solder heat resistance test Each test piece coated with rosin-based flux is immersed in a solder bath set at 260 ° C for 30 seconds once, washed with modified alcohol to wash the flux, dried, and then visually cured. The peeling of the film was evaluated.

Solder heat resistance ◎: Those that did not peel off even after repeating the solder heat resistance test three times ○: Those that did not peel off in one solder heat resistance test △: Those that did slightly peel off in one solder heat resistance test × 1: Significant peeling occurred in one solder heat resistance test

2-2. Printability The curable compositions (inks) of Examples 1 to 3 and Comparative Examples 1 and 2 were applied to a FR-4 copper-clad laminate (copper thickness 70 μm) having a size of 100 mm × 150 mm and a thickness of 1.6 mm. The entire surface was printed using a 200 mesh polyester bias plate by a screen printing method. Each curable composition was continuously printed up to the 100th sheet on the copper-clad laminate, and the printability was evaluated in the state of the ink printed on the 100th copper-clad laminate.

Printability ○: No ink fading △: Some ink fading ×: Ink fading

2-3. Foreign matter after stirring 100 g of the curable compositions of Examples 1 to 3 and Comparative Examples 1 and 2 immediately after mixing the first liquid and the second liquid were stirred with a drilling machine for 5 minutes. Each curable composition after stirring is applied to a FR-4 copper-clad laminate (copper thickness 70 μm) having a size of 100 mm × 150 mm and a thickness of 1.6 mm by a screen printing method using a 100 mesh polyester bias plate. It was printed on the entire surface and dried in a hot air circulation type drying furnace at 80 ° C. for 30 minutes. Next, the printed wiring board exposure machine HMW-680GW (manufactured by ORC Manufacturing Co., Ltd.) was used to expose with an integrated light intensity of 500 mJ / cm ² , followed by a box furnace (KBF848N2: manufactured by Koyo Thermo System Co., Ltd.) at 150 ° C. for 60 minutes. ) Was heat-cured to obtain a test piece. This test piece was observed with an optical microscope (magnification: 100 times) to evaluate foreign substances.

Foreign matter after stirring ○: No foreign matter Δ: Foreign matter in some places ×: Foreign matter on the entire surface Table 2 below shows the evaluation results of solder heat resistance, printability, and foreign matter after stirring.

As shown in the comparison between Examples 1 to 3 and Comparative Examples 1 and 2 in Table 2, when the compound containing (C) triglycidyl isocyanurate was blended in the alkali-developing curable composition, the second By setting the viscosity of the liquid and the viscosity of the curable composition within the scope of the present invention, it is possible to improve the printability and the generation of foreign substances after stirring, and to improve the solder heat resistance of the obtained cured film. became. Further, from the comparison between Examples 1 and 2 and Example 3, the solder heat resistance is further improved by using (E) an isocyanurate ring-containing compound containing an ethylenically unsaturated group as the photopolymerizable polyfunctional monomer. I found that I could do it.

Claims (5)

(A) Alkali-soluble resin and
(B) Photopolymerization initiator and
1st solution containing
(C) A second solution containing trichloroisocyanuric acid and having a viscosity at 25 ° C. and 5 rpm in the range of 10 to 100 dPa · s.
A curable composition having a viscosity at 25 ° C. and 5 rpm in the range of 100 to 500 dPa · s, which is a mixture of the above.
Curability characterized in that (E) a photopolymerizable polyfunctional monomer and (F) an inorganic filler are contained in either or both of the first liquid and the second liquid before mixing, respectively. Composition. The curable composition according to claim 1, wherein the mixing ratio of the first liquid and the second liquid is 6: 4 to 9: 1. (E) The photopolymerizable polyfunctional monomer
The curable composition according to claim 1 or 2, which comprises an isocyanurate ring-containing compound containing an ethylenically unsaturated group. The curable composition according to any one of claims 1 to 3, further comprising (D) an epoxy resin. The curable composition according to any one of claims 1 to 4, which is used as an ink for screen printing.