JP2938960B2 - Liquid resist ink composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid resist ink composition suitable for manufacturing a printed wiring board and developable with a dilute alkaline aqueous solution.

[Conventional technology]

Conventionally, a screen printing method is often used as a resist pattern forming method for various types of printed wiring boards for consumer and industrial use. However, this method has a low resolution, and causes ink bleeding and line gaps during printing. Ink filling failure occurs, and it is no longer possible to cope with recent high density. In order to solve such problems, dry film and liquid developable resist inks have been developed, and among them, those which can be developed with a dilute alkaline aqueous solution have been particularly noted.

As such a liquid resist ink composition,
JP-B-56-40329 and JP-B-57-45785 disclose a composition containing a reaction product obtained by reacting an unsaturated monocarboxylic acid with an epoxy resin and adding a polybasic acid anhydride as an essential component. I have.

JP-A-61-243869 discloses a thermosetting component comprising a resin soluble in a dilute alkali aqueous solution obtained by adding an acid anhydride to a novolak type epoxy acrylate, a photopolymerization initiator, a diluent and an epoxy compound. A photosensitive resin composition for a liquid resist ink of a weak alkali development type, comprising:

[Problems to be solved by the invention]

The object of the present invention is to add a polybasic acid anhydride while reacting an unsaturated monocarboxylic acid with an epoxy resin, or to use a resin product according to the conventional method of adding an acid anhydride to a novolak type epoxy acrylate. In addition, it has various properties superior to those of the prior art, and has excellent resolution, photocurability and thermosetting properties, and also has an adhesive property for a cured coating film, heat resistance, hardness, solvent resistance, acid resistance, and electric resistance. An object of the present invention is to provide a liquid resist ink composition having excellent properties and plating resistance.

[Means and actions for solving the problem]

The liquid resist ink composition developable with a dilute aqueous alkaline solution according to the present invention comprises: A. a reaction product of an acid anhydride of tribasic acid or more and 2-hydroxyethyl (meth) acrylate alone or (meth) acrylic acid; The mixture contains a UV-curable resin obtained by reacting the mixture with an epoxy resin or an epoxy (meth) acrylate, B. a photopolymerization initiator, C. a diluent, and D. a thermosetting epoxy compound.

<About UV-curable resin A> Examples of tribasic acid or higher acid anhydrides include, for example, aromatic polycarboxylic anhydrides such as trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic anhydride. it can.

In the reaction between the acid anhydride and 2-hydroxyethyl (meth) acrylate, 1 mol or more of the latter is reacted with 1 mol of the former anhydride. For example, 1 mole or more of 2-hydroxyethyl (meth) acrylate may be reacted with 1 mole of trimellitic anhydride. This is because, when the anhydrous part remains in the reaction product, gelation proceeds during the reaction of this with an epoxy resin or the like, and the desired ultraviolet curable resin cannot be obtained satisfactorily. If necessary, (meth) acrylic acid is used in combination with the reaction product to adjust the solubility of the resin.

Examples of the epoxy resin to be reacted with the reaction product include bisphenol A type, phenol novolak type, cresol novolak type and other epoxy resins, and respective epoxy (meth) acrylates corresponding thereto.

The epoxy (meth) acrylate is obtained by reacting the above-mentioned epoxy resin with acrylic acid or methacrylic acid in an amount of less than 1 mole, preferably 0.6 mole or less based on 1 mole of the epoxy group by a conventional method.

The ultraviolet curable resin used in the present invention is obtained by reacting the above reaction product and the like with an epoxy resin and the like. The acid value of the obtained ultraviolet curable resin is preferably 45 to 160 mg KOH.
/ g, particularly preferably 60/150 mgKOH / g, whose acid value is 4
If it is less than 5, alkali solubility will be poor, and conversely 160
If it is larger than the above, it becomes a factor of deteriorating resist properties such as alkali resistance and electrical properties of the cured film.

The number of ethylenically unsaturated bonds contained in one molecule of the ultraviolet curable resin is selected so as to secure a necessary photocuring rate and sufficiently obtain the above-mentioned properties as a resist.

<About Photopolymerization Initiator B> Examples of photopolymerization initiators include benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, and alkyl ethers thereof; acetophenone, 2,2-dimethoxy-2.
-Phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2
-Methyl-1- [4- (methylthio) phenyl] -2-
Acetophenones such as morpholino-propan-1-one; anthraquinones such as 2-methylanthraquinone and 2-amylanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropyl Thioxanthones such as thioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone or xanthones; known photopolymerization accelerators such as benzoic acid or tertiary amine You may use together with an agent.

The photopolymerization initiator is preferably used in an amount of 0.1 to 30 parts by weight, particularly preferably 1 to 25 parts by weight, based on 100 parts by weight of the ultraviolet curable resin.

<Diluent> As the diluent, a photopolymerizable monomer and / or an organic solvent can be used. Examples of the photopolymerizable monomer include 2-hydroxyethyl acrylate and 2-hydroxyethyl acrylate.
Hydroxypropyl acrylate, N-vinylpyrrolidone, acryloyl morpholine, methoxytetraethylene glycol acrylate, methoxy polyethylene glycol acrylate, polyethylene glycol diacrylate, N, N-dimethylacrylamide, N-methylolacrylamide, N, N-dimethylaminopropylacrylamide, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylate, water-soluble monomers such as melamine acrylate and each methacrylate corresponding to the acrylate; and diethylene glycol diacrylate, triethylene glycol diacrylate, propylene glycol diacrylate, Tripropylene glycol diacrylate, phenoxyethyl acrylate tetrahydro Le frills acrylate,
Cyclohexyl acrylate, tromethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, isobonyl acrylate, cyclopentanyl (mono or di) acrylate Water-insoluble, such as cyclopentenyl (mono- or di-) acrylate, methacrylates corresponding to the acrylate, mono-, di-, tri- or more polyesters of polybasic acid and hydroxyalkyl (meth) acrylate monomer;
Further, high molecular weight acrylate monomers such as polyester acrylate, urethane acrylate, bisphenol A type epoxy acrylate, phenol novolak type epoxy acrylate and cresol novolak type epoxy acrylate can be exemplified.

Further, as the organic solvent, methyl ethyl ketone,
Ketones such as cyclohexanone; aromatic hydrocarbons such as toluene and xylene; cellosolves such as cellosolve and butyl cellosolve; carbitols such as carbitol and butyl carbitol; ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate and butyl Acetates such as carbitol acetate can be exemplified.

The water-soluble monomer, the water-insoluble monomer and the high-molecular-weight acrylate monomer dilute the ultraviolet-curable resin to make it easy to apply, adjust the acid value, and provide photopolymerizability. When the mixing ratio of the water-soluble monomer increases,
Although the solubility in an aqueous alkali solution is improved, the water resistance of a completely cured resist material is reduced when it is frequently used, so that a water-insoluble monomer or a high molecular weight acrylate monomer is used as a water-soluble monomer, and the resist material is hardly soluble in an aqueous alkali solution. It may be suitably used in an amount not to exceed the limit, preferably within the range of 100% by weight or less of the ultraviolet curable resin. The organic solvent,
The ultraviolet curable resin is dissolved and diluted to make it applicable as a liquid and dried to form a film.

The diluent, alone or as a mixture of two or more, preferably 30 to 3 parts by weight of the ultraviolet curable resin 100 parts by weight.
50 parts by weight, particularly preferably 50 to 250 parts by weight, is blended.

<About thermosetting epoxy compound D> Examples of thermosetting epoxy compounds include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, N-glycidyl type epoxy resin and alicyclic epoxy resin. Those having two or more epoxy groups in the molecule can be mentioned, and these are preferably 10 to 150 parts by weight, particularly preferably 30 to 100 parts by weight, based on 100 parts by weight of the ultraviolet curable resin. .

The liquid resist ink composition obtained as described above may contain, if necessary, a known filler such as barium sulfate, silicon oxide, talc, clay, or calcium carbonate; phthalocyanine blue, phthalocyanine green, or titanium oxide. , A known coloring pigment such as carbon black; various additives such as an antifoaming agent, an adhesion promoter or a leveling agent, or a known polymerization inhibition such as hydroquinone, hydroquinone monomethyl ether, pyrogallol, tertiary butyl catechol, and phenothiazine. An agent may be added.

As a method of using the liquid resist ink composition according to the present invention, for example, sprayed on a printed wiring board, applied by a roll coater or screen printing, etc., then pre-cured at 70 to 90 ° C. to volatilize the solvent, By applying a mask with a pattern to the dried ink surface, and irradiating 200 to 1500 mj of ultraviolet light using a chemical lamp, constant-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, xenon lamp, metal halide lamp, etc. After forming a pattern, developing and then heating, a desired resist film can be formed. In addition, this composition can be used not only as a solder resist but also as an etching resist by not applying post-curing by heat.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. "Part" and "%" used below
Are all based on weight.

<Example 1> Reaction product 1 obtained by adding 1 mol of 2-hydroxyethyl acrylate to 1 mol of trimellitic anhydride
One mole of “Epicoat 154” (a phenol novolak type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd. with an epoxy equivalent of 178) was reacted with the mole in a conventional manner using carbitol acetate as a solvent. This resin product is
A viscous liquid containing 30% carbitol acetate,
The mixture had an acid value of 81 mg KOH / g. Hereinafter, the resin product is referred to as a resin (A-1).

[Ingredients] Resin (A-1) 40 parts "Epicoat 154" 18 parts Benzyl dimethyl ketal 3 parts "Modaflow" (leveling agent manufactured by Monsanto) 1 part Silica (average particle size 1μ) 25 parts Phthalocyanine green 0.5 part Swallows 1500 "(Aromatic solvent manufactured by Maruzen Petrochemical Co., Ltd.) 12 parts Dicyandiamide 0.5 parts Total 100 parts Kneading the components of the above composition with a three-stage roll to prepare a weak alkaline development type liquid resist ink. Is applied by screen printing on the entire surface of a copper-clad laminate made of a glass epoxy base material of copper foil 35μ and a printed wiring board on which a pattern has been formed by etching it in advance, and 90 ° C. in order to volatilize the solvent. Was performed for 20 minutes to obtain a dried coating film having a thickness of 20 μm. After that, the mask on which the pattern was drawn was directly applied to the coating film surface, irradiated with 500 mj of ultraviolet light, and then developed with a 1% aqueous solution of sodium carbonate as a developing solution to form a pattern.
Heat curing was performed at 30 ° C. for 30 minutes to prepare a test piece.

Example 2 The reaction product obtained by adding 1 mol of 2-hydroxyethyl acrylate to 1 mol of trimellitic anhydride was added.
To a mixture of 8 mol and 0.2 mol of acrylic acid, 1 epoxy equivalent of “Epiclon N-730A” (a phenol novolak type epoxy resin manufactured by Dainippon Ink and Chemicals Co., Ltd. with an epoxy equivalent of 176) was constantly added using carbitol acetate as a solvent. The reaction was carried out by the following method. The resin product is a viscous liquid containing 30% carbitol acetate and contains 72 mg KO
It showed an acid value of H / g. Hereinafter, the resin product is referred to as a resin (A
-2).

[Ingredients] Resin (A-2) 40 parts "TEPIC" (epoxy resin with an epoxy equivalent of 100, manufactured by Nissan Chemical Co., Ltd.) 10 parts Hydroxyethyl acrylate 2 parts "Irgacure 907" (photopolymerization initiator, manufactured by Ciba Geigy) 2 parts Silicone leveling agent 0.5 parts Talc (average particle diameter 3μ) 15 parts Phthalocyanine green 0.5 parts Butyl acetate 29.5 parts 2-methylimidazole 0.5 parts Total 100 parts A mixture of the above components is kneaded in the same manner as in Example 1 to obtain a liquid resist. After preparing the ink, the ink was used in the same manner as in Example 1 to prepare a copper-clad laminate made of a glass epoxy base material having a copper foil of 35 μm and a printed wiring board on which a pattern was formed by etching the laminate in advance. A test piece was prepared by coating the entire surface by a spray method.

<Comparative Example 1> Acrylic acid was added to one epoxy equivalent of “Epicoat 154”.
0.85 mol of phthalic anhydride was reacted with the epoxy acrylate obtained by reacting 1.05 mol by a conventional method using cellosolve acetate as a solvent. This resin product is
It was a viscous liquid containing 30% cellosolve acetate and had an acid value of 85 mg KOH / g as a mixture.

A liquid resist ink was prepared by kneading the components having the same composition as in Example 2 in the same manner as in Example 1, except that the resin (A-2) was replaced with the resin of the resin product. In the same manner as in Example 1, a copper-clad laminate made of a glass epoxy base material having a copper foil of 35 μm and a printed wiring board on which a pattern was formed by etching the copper-clad laminate in advance were applied by screen printing, and then tested. Created a piece.

<Test Results> Table 1 shows the results of various physical property tests on the test pieces of the liquid resist inks obtained in the above Examples and Comparative Examples.

[Effects of the Invention] As described above, the liquid resist ink composition according to the present invention can be easily developed with a dilute alkaline aqueous solution, and has excellent resolution, photocurability, and thermosetting properties. In the production of a curable resin, the reaction time can be easily reduced. Further, the cured coating film of the liquid resist ink composition also has excellent adhesion, heat resistance, hardness, solvent resistance, acid resistance, electric properties, plating resistance, and the like.

Therefore, the liquid resist ink composition can be suitably used as a solder resist ink or an etching resist ink particularly for the production of a commercial or industrial printed wiring board due to the above effects.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshikazu Oda 58, Ijiri-cho, Iseda-cho, Uji-city, Kyoto, Japan (56) References JP-A-61-243869 (JP, A) JP-A-63- 312375 (JP, A) JP-A-4-170480 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09D 11/00 C09D 11/10

Claims (1)

(57) [Claims] A. A reaction product of an acid anhydride of three or more basic acids with 2-hydroxyethyl (meth) acrylate alone or a mixture thereof with a (meth) acrylic acid is used as an epoxy resin or an epoxy (meth) acrylate. A liquid resist ink composition developable with a dilute alkaline aqueous solution, comprising: an ultraviolet curable resin which is reacted with B .; a photopolymerization initiator; C. a diluent; and D. a thermosetting epoxy compound.