JPH0122313B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a one-component epoxy resin ink composition. This material has excellent electrical insulation, moisture resistance, heat resistance, chemical resistance, and adhesion, and is made of silver,
It has the ability to prevent discoloration and migration of copper, and has fast curing properties at medium to high temperatures of 130°C to 200°C, so it can be used for manufacturing printed circuit boards, etc. (Prior Art) Several methods are known for manufacturing conventional circuit boards. That is, glass frit is used as a binder on an inorganic insulating substrate such as ceramic or glass,
The so-called thick film hybrid integrated circuit board (A) is made by forming a desired circuit using silver, platinum, or palladium-based conductors by screen printing, and then firing it at high temperature.Phenol resin or epoxy resin is applied to various commercially available laminated insulating substrates. etc. as a binder, a desired circuit is formed by screen printing using silver-based conductors, etc., and then baked at medium to high temperature.
(B), Printed circuit board (C) on which the desired circuit is formed by etching the copper foil of various commercially available laminates. However, the surfaces of each of the conductor circuits (A), (B), and (C) are exposed and are therefore easily affected by the atmosphere. Therefore, accidents are likely to occur due to corrosion of the conductor circuit portion due to conductor corrosive substances and moisture contained in the atmosphere. In order to prevent such accidents and further improve the reliability of the circuit, a method is generally used in which a protective coating called a permanent resist is formed on the circuit by screen printing or the like. (Problem to be solved by the invention) In this case, the protective coating has electrical insulation, moisture resistance,
Various performances such as chemical resistance, adhesion, and hardness are required. Furthermore, in cases (A) and (C) above, the circuits are often minute and complex, and when plating with nickel, gold, copper, solder, etc., there is a risk of short circuits, and In order to prevent this, a method has been adopted in which a protective coating called resist ink is applied in advance by screen printing on areas where plating is not required, is cured to form a coating film, and then plating is applied only to the necessary areas. Protective paints are required to have ink functions such as viscosity suitable for screen printing, threadability, and thixotropic properties. Recently, there have been high demands for electronic devices such as smaller size, lighter weight, higher density, and higher reliability. Also, discoloration and migration of copper circuits have become a major problem. There are almost no useful materials for protective coatings having anti-discoloration and anti-migration effects other than triazine resins and bis-maleimide-triazine resins. Various types of protective paints have been known, but all of them other than glass-based paints have poor discoloration or migration prevention properties. The triazine resin system and bis-maleimide
Triazine resins have problems in handling such as curing conditions (temperature, time) and pot life, and are therefore unsatisfactory. In view of these circumstances, the present inventors have conducted extensive research and have developed a one-component epoxy resin ink composition for protective coatings that has excellent storage stability, fast curing properties, and can prevent discoloration and migration. I came to find something. (Means for Solving the Problems) That is, the present invention uses 20 to 100 parts by weight of filler, 2-vinyl 4,
5 to 20 parts by weight of 6-diamino-s-triazine,
This composition contains 10 to 40 parts by weight of polyvinyl para-phenol and a certain imidazole compound in a proportion of 0.05 to 8 parts by weight. When the composition of the present invention is heated, 2-vinyl-4,
The vinyl group of 6-diamino-s-triazine is cleaved and polymerized, and at the same time, the two amino groups of the triazine ring also react with the epoxy resin due to the action of the imidazole compound. Further, the hydroxyl group of polyvinyl-para-phenol also reacts with the epoxy resin due to the action of the imidazole compound. Furthermore, in addition to reacting with 2-vinyl-4,6-diamino-s-triazine and polyvinyl-para-phenol, the epoxy resin also undergoes anionic polymerization under the action of the imidazole compound. In this way, many reactions occur almost simultaneously,
It is believed that a coating film can be obtained that exhibits various properties necessary for circuit board inks, such as heat resistance, chemical resistance, discoloration resistance, and anti-migration function. Epoxy resins suitable for carrying out the present invention include polyglycidyl ethers of polyhydric phenols, such as bisphenol-A-diglycidyl ether, bisphenol-F-diglycidyl ether, other epoxidized phenol-novolac resins, and epoxidized cresol novolac resins. It is. Fillers include barium sulfate, calcium carbonate, talc, mica,
These include silica, aluminum hydroxide, alumina, etc., and these can be used alone or in combination. Of course, fillers other than these can also be used.

[Formula] 2-vinyl-4,6-diamino-s-triazine shown by the above structural formula can be obtained by the method of reacting biguanide with acrylic acid chloride [J.Am.Chem.
Soc., 80, 988 (1958)], dicyandiamide and β-
Method for reacting dimethylamino-propionitrile (French Patent No. 1563255) and 1,2
-di{4',6'-diamino-s-triazinyl-
(2)′}-It can be produced by heating cyclobutane under reduced pressure (Japanese Patent Publication No. 46-35068), and the amount added is 5 to 20 parts by weight per 100 parts by weight of epoxy resin. parts, particularly preferably 7 to 15 parts by weight. If the amount of 2-vinyl-4,6-diamino-s-triazine added is less than the above-mentioned range, the effect of preventing discoloration and migration will decrease, and the curing speed will also decrease, making it impractical. On the other hand, if the amount is too high, the cured coating film becomes brittle and lacks performance as a protective coating. The practice of this invention requires the use of polyvinyl-para-phenol represented by the following structural formula. The substance significantly improves the adhesion between the coating film and the substrate, and also prevents oozing of the thin pattern coating film during curing.

[Formula] The average degree of polymerization is in the range of 40 to 70, and the particle size is preferably 200 to 300 mesh. A typical imidazole compound used in the present invention is 2,4-diamino-6-{2
Methylimidazolyl-(1)}-ethyl-s-triazine, 2,4-diamino-6-{2-methylimidazolyl-(1)}-ethyl-s-triazine-isocyanuric acid adduct, 2-phenyl-4, 5-dihydroxymethylimidazole (2PHZ), 2-phenyl-4-methyl-5-hydroxymethyl-imidazole, 2-phenyl-4-benzyl-5-hydroxymethyl-imidazole, 4,4'-methyl-bis-(2 -ethyl-5-methyl-imidazole) and the like, imidazole compounds that exhibit a long pot life for liquid epoxy resins are used. Until now, it has been generally accepted that the pot life of a composition in which a compound having a phenolic hydroxyl group, that is, a polyvinyl-para-phenol and an imidazole compound, is uniformly dispersed in a liquid epoxy resin is very short. In order to obtain a one-component epoxy resin ink composition that has a long pot life and is fast curing, the present inventors conducted extensive research and investigated the degree of polymerization of polyvinyl-para-phenol, the particle size, and the type of imidazole compound. However, the results described above were obtained. Furthermore, color pigments may be added to the composition of the present invention as required, and furthermore, a thixotropic agent, an antifoaming agent, a surface fluidity modifier, or an organic solvent to adjust the viscosity may be added to the composition of the present invention to impart suitability for screen printing. may be added. The curing temperature of the composition according to the invention is preferably in the range of 130 to 200°C. (Example) The compositions shown in Table 1 were uniformly dispersed and kneaded using a three-roll mill to a degree of crumbling of 10 microns or less, and the numerical units are expressed in parts by weight. Tables 2 and 3 show the results of performance tests conducted on compositions obtained by formulating each of the Examples and Comparative Examples shown in the same table. The suffix numbers in the table mean test conditions (Note).

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Claims (1)

[Scope of Claims] 1. A one-component epoxy resin ink composition comprising an epoxy resin, 2-vinyl-4,6-diamino-s-triazine, polyvinyl-para-phenol, an imidazole compound, and a filler. . 2 Patent for blending 5 to 20 parts by weight of 2-vinyl-4,6-diamino-s-triazine, 10 to 40 parts by weight of polyvinyl para-phenol, and 0.05 to 8 parts by weight of an imidazole compound to 100 parts by weight of epoxy resin. A one-component epoxy resin ink composition according to claim 1.