JPS624055B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention has heat resistance, moisture resistance, electrical performance, adhesion,
Regarding thermosetting resin compositions with excellent toughness etc.
In particular, the present invention relates to a thermosetting resin composition that is suitable for use in laminates, molded products, and the like that are manufactured through a B-staged state. It has been well known that when an epoxy compound is reacted with an isocyanate compound, an oxazolidone compound having excellent heat resistance is produced. However, since isocyanate groups are highly reactive, the reaction with epoxy groups proceeds even at room temperature, and in varnishes, B-staged prepregs, molding materials, etc., the resin reaches a gel state in a short time, reducing the pot life. It had shortcomings such as a lack of storage stability, such as being extremely short and easily deteriorating due to moisture absorption. In order to improve this drawback, there is a method in which the isocyanate group is reacted with a masking agent such as phenol or cresol in advance to turn it into a urethane compound that is stable at room temperature, and during curing, the masking agent is dissociated by heating and removed by evaporation to regenerate the isocyanate group. Proposed. (For example, Japanese Patent Publication No. 53-14095). However, in this method, the working environment is seriously disturbed by the dissociated masking agent, and for example, the laminate,
When used in molded products, etc., if the masking agent dissociates during curing, it causes voids, etc., and is therefore not suitable for practical use. On the other hand, the isocyanate group is reacted with the phenolic hydroxyl group of the epoxy/phenol compound to form a urethane bond, and during curing, the urethane bond is dissociated into an isocyanate group and a hydroxyl group. A method has been proposed in which phenol compounds are also reacted (Japanese Patent Publication No. 1973-
Publication No. 13560). However, in this method, free isocyanate groups tend to remain in the final cured product because the masked isocyanate groups are dissociated.
The disadvantage is that the final cured product has significantly poor moisture resistance. Therefore, it is unsuitable for use as an electrical insulating material that requires a high degree of moisture resistance, such as printed wiring boards. Additionally, in general, urethane bonds in which isocyanate groups are masked with phenolic hydroxyl groups have a dissociation temperature of at most 130°C.
Because of this, for example, during the drying process when creating B-staged prepregs, the masked isocyanate groups easily change into free isocyanate groups, resulting in very poor storage stability at the B-stage. There are drawbacks. As a result of extensive research, the present inventors were able to eliminate the above-mentioned drawbacks of the conventional technology and obtain a B-stage compound with excellent storage stability, and the final cured product has excellent heat resistance, electrical properties, and moisture resistance. We have now discovered a thermosetting resin composition that has excellent properties. The thermosetting resin composition of the present invention has an average molecular weight of 400 to 1000 derived from the reaction between bisphenol A and epichlorohydrin, and contains an epoxy compound having an alcoholic hydroxyl group and a urethane group having an isocyanurate ring. First, the alcoholic hydroxyl group of the epoxy compound and the isocyanate group of the polyisocyanate compound are reacted using a polyisocyanate compound having two or more isocyanate groups in the molecule. compound and/or
Alternatively, diandicyamide or polycarboxylic acid anhydride is added. In the resin composition according to the present invention, since the isocyanate group is a urethane bond masked with an alcoholic hydroxyl group, the storage stability is extremely good. Furthermore, as in the present invention, urethane bonds whose isocyanate groups are masked with alcoholic hydroxyl groups have a higher dissociation temperature than urethane bonds whose isocyanate groups are masked with phenolic water residues. Urethane bonds are almost never dissociated to produce free isocyanate groups during the heat-kneading process and the like when creating a B-staged molding material. Therefore, the resin composition of the present invention can be a B-stage compound with extremely excellent storage stability. Furthermore, even if the urethane bonds are dissociated in the final curing stage and free isocyanate groups are generated, the resin composition of the present invention is made of aromatic amine compounds and/or dicyandiamide or polycarboxylic acid anhydrides that are highly reactive with isocyanate groups. , no free isocyanate groups remain in the final cured product. In addition, at the final curing stage, the polyepoxy compound with alcoholic hydroxyl groups that was used as a masking agent for isocyanate groups also reacts, so the masking agent does not evaporate as volatile matter when molding products such as laminates. Therefore, it can be formed neatly without voids. This cannot be achieved by conventional methods in which isocyanate groups are masked with phenol, cresol, etc., and the masking agent is removed by evaporation as volatile matter during curing. A large number of reactions occur in the final curing reaction of the thermosetting resin composition according to the present invention. For example, formation of an oxazolidone ring by direct addition of an epoxy group to a urethane bond, or ring opening of an epoxy group by reaction of an epoxy group with an aromatic amine compound and/or dicyandiamide or polycarboxylic anhydride, and further dissociation from a urethane bond. The formation of an oxazolidone ring by the reaction between the isocyanate group and the epoxy group, or the formation of a urea bond by the reaction between the isocyanate group and an aromatic amine compound and/or dicyandiamide, or the reaction between the isocyanate group and a polycarboxylic acid anhydride. It is presumed that the formation of imide bonds and amide bonds, or the formation of uretdione rings and isocyanurate rings due to polymerization of isocyanate groups, etc. are occurring. As described above, the final cured product of the thermosetting resin composition of the present invention has a portion having an oxazolidone ring, a portion having a structure similar to that of a conventional cured epoxy resin, or other parts such as a urea bond, an imide bond, an isocyanurate ring, etc. Because it contains many structures, in addition to the excellent adhesion and toughness of conventional epoxy resins, it also has excellent heat resistance not found in conventional epoxy resins.
This can result in a molded product with electrical performance, etc. In the present invention, the epoxy compound used has an average molecular weight of 400 to 1000, which is derived from the reaction between bisphenol A and epichlorohydrin. When the average molecular weight is less than 400, the content of alcoholic hydroxyl groups decreases, and the function of the isocyanate group as a masking agent decreases, making B stable at room temperature.
Less likely to become a stage compound. On the other hand, if the molecular weight exceeds 1000, the crosslinking density of the final cured product will decrease, resulting in a decrease in heat resistance. However, as long as the epoxy compound is blended in an amount that can completely mask the isocyanate groups of the polyisocyanate compound, there is no problem in using polyglycidyl ether of cresol novolac, which has no alcoholic hydroxyl groups, in combination. In addition, in the present invention, polyisocyanate compounds having an isocyanurate ring, not containing a urethane group, and having two or more isocyanate groups include, for example, methane diisocyanate, ethane-1,2-diisocyanate, butane-1,1-diisocyanate, and butane-1,1-diisocyanate. 1,2-diisocyanate, butane 1,4-diisocyanate, propane-1,3-
Diisocyanate, trans vinyl diisocyanate, 2-butene-1,4-diisocyanate, 2-methylbutane-1,4-diisocyanate, pentane-1,5-diisocyanate, 2,
2-dimethylpentane-1,5-diisocyanate, hexane-1,6-diisocyanate, peptane-1,7-diisocyanate, octane-
1,8-diisocyanate, nonane 1,9-diisocyanate, decane 1,10-diisocyanate, dimethylsilane diisocyanate, diphenylsilane diisocyanate, ω,ω'-1,3-
Dimethylbenzene isocyanate, ω, ω′-1
-4-dimethylbenzenediisocyanate, ω,
ω'-1,3-dimethylcyclohexane diisocyanate, ω,ω'-1,4-dimethylcyclohexane diisocyanate, ω,ω'-1,4-dimethylbenzene diisocyanate, ω,ω'-
1,4-dimethylnaphthalene diisocyanate,
ω,ω'-1,5-dimethylnaphthalene diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-phenylene diisocyanate, 1,4 -phenylene diisocyanate, 2,
4-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,6-tolylene diisocyanate, 3,5-tolylene diisocyanate,
diphenyl ether-4,4'-diisocyanate, diphenyl ether-2,4-diisocyanate, naphthalene-1,4-diisocyanate,
naphthalene-1,5-diisocyanate, biphenyl-4,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate,
2,3-dimethoxybiphenyl-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate 4,4'-dimethoxydiphenylmethane-3 , 3′-diisocyanate,
Diphenyl sulfide-4,4'-diisocyanate, diphenyl sulfone-4,4'-diisocyanate, polymethylene polyphenyl isocyanate, triphenylmethane triisocyanate, triphenyl isocyanate, tris(4-phenyl isocyanate thiophosphate) eight), 3,
It is a trimer such as 3',4,4'-diphenylmethanetetrisocyanate or a pentamer polyisocyanate compound having an isocyanurate ring.
Further, aromatic amine compounds and/or dicyandiamide used in the present invention are used, and examples of the aromatic amine compounds include ortho-phenyl diamine, meta-phenylene diamine, para-phenylene diamine, diamylephenyl ether,
Diaminodiphenyl sulfone, diaminodiphenylmethane, benzidine, 4,4'-bis(ortho-toluidine), 4,4'-thiodianiline, dianisidine, methylenebis(ortho-chloroaniline), 2,4-toluenediamine, bis( 3,4
-diaminophenyl)sulfone, 4-chloro-ortho-phenylenediamine, 4-methoxy-6-
Examples include methyl-meta-phenylenediamine and meta-aminobenzylamine. Further, the polycarboxylic acid anhydrides used in the present invention include, for example, phthalic anhydride, itaconic anhydride, succinic anhydride, alkenyl acid anhydride, dodecenylsuccinic anhydride, tricarballylic anhydride, linoleic acid adduct of maleic anhydride, Chlorendic acid, maleic anhydride-vinyl ether copolymer,
Maleic anhydride-styrene copolymer, nadic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, anhydride cyclopentanetetracarboxylic acid,
Examples include benzophenonetetracarboxylic anhydride, benzotetracarboxylic anhydride, ethylene glycol bistrimelitate, and glycerin tristomellitate. Further, in the present invention, the blending ratio of the polyepoxy compound having an alcoholic hydroxyl group and the polyisocyanate compound can be appropriately selected, but preferably 0.5 to 5 equivalents of epoxy group and 0.2 to 3 equivalents of alcoholic hydroxyl group per equivalent of isocyanate group. It is equivalent. If the amount is less than 0.5 equivalent of epoxy group per equivalent of isocyanate group, many urethane bonds remain in the final cured product, or free isocyanate tends to remain, resulting in decreased heat resistance and moisture resistance. Furthermore, when the amount of epoxy groups exceeds 5 equivalents, the proportion of oxazolidone rings in the final cured product decreases, resulting in a decrease in heat resistance. On the other hand, if the amount of alcoholic hydroxyl groups is less than 0.2 equivalent per equivalent of isocyanate group, a large amount of free isocyanate will remain in the polyepoxy-urethane compound, resulting in poor storage stability. Furthermore, if the amount of alcoholic hydroxyl groups exceeds 3 equivalents, a large number of hydroxyl groups will remain in the final cured product, resulting in a decrease in moisture resistance and the like. In addition, a polyepoxy urethane compound obtained by reacting the alcoholic hydroxyl group of a polyepoxy compound having an alcoholic hydroxyl group with the isocyanate group of a polyisocyanate compound as described above and an aromatic amine compound and/or dicyandiamide or polycarboxylic acid anhydride. The blending ratio with the compound can be selected as appropriate depending on the purpose, but it is preferably 0.1 to 2 equivalents of amine equivalent or acid anhydride equivalent to 1 equivalent of epoxy group. If the amine equivalent or acid anhydride equivalent is less than 0.1 equivalent per equivalent of epoxy group, the excellent toughness and adhesive properties of conventional cured epoxy resin products will decrease, and When the amount exceeds the equivalent, the aromatic amine compound and/or dicyanamide or polycarboxylic acid anhydride tends to remain unreacted in the final cured product, resulting in a decrease in heat resistance, moisture resistance, chemical resistance, etc. In the present invention, the addition of a catalyst is useful because the reaction proceeds more rapidly. Catalysts used in the present invention include those commonly used as urethane bond-forming catalysts and oxazolidone ring-forming catalysts, or those used as catalysts for the reaction of epoxy compounds with acid anhydrides, aromatic amine compounds, and/or dicyandiamide. For example, tertiary amines such as trimethylamine, triethylamine, benzyldimethylamine, dimethylaminomethylphenol, tris(dimethylaminomethyl)phenol, N-methylmorpholine, N-ethylmorpholine, trifluoride Boron trifluoride-amine complex salts such as boron-piperidine complex salts and boron trifluoride-monoethylamine complex salts,
Quaternary ammonium salts such as cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, dodecyltrimethylammonium iodide, trimethyldodecylammonium iodide, trimethyldodecylammonium chloride, lithium chloride, tin chloride, iron chloride,
Metal halides such as zinc chloride and aluminum chloride, metal alkoxides such as lithium butoxide, potassium butoxide, aluminum isopropoxide, aluminum phenoxide, calcium ethoxide, magnesium ethoxide, phenoxide compounds, or cobalt naphthenate, tetrabutyltin, trimethyltin Organometallic compounds such as hydroxide, dimethyltin chloride, dibutyltin dilaurylate, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2
-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2
-Methylimidazole, 2-isopropylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-isopropylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-andecylimidazole, 2-heptadecyl imidazole, 1-cyanoethyl-2-andecylimidazole, 1-azine-2-methylimidazole, 1-azine-2-
Ethyl-4-methylimidazole, 1-azine-
There are imidazole compounds such as 2-andecylimidazole. One or more of the following catalysts from 0.01 to
It is useful to include 10 parts by weight. Furthermore, various additives and fillers such as flame retardants, pigments, dyes, and reinforcing agents may be added to the resin composition as required. The present invention will be explained in more detail below with reference to Examples. Example 4,4'-4''-trimethyl 3,3',3''-triisocyanate 150 gr of 2,4,6-triphenyl isocyanurate, diglycidyl ether obtained from the reaction of bisphenol A and epichlorohydrin (average Molecular weight approximately 700, epoxy equivalent approximately 340gr,
350gr of alcoholic hydroxyl equivalent drug (700), 200gr of polyglycidyl ether of cresol novolak (molecular weight: approx. 1400, epoxy equivalent: approx. 230, no alcoholic hydroxyl group), 1gr of dimethylbenzylamine, and 700gr of MEK. Concentration 50%
A solution was prepared. This solution was stirred at 70°C for 10 hours, and it was confirmed by infrared absorption spectrum that a polyepoxy-urethane compound had been produced. A varnish was prepared by adding 90g of hexahydrophthalic anhydride to this solution. A glass cloth was impregnated with this varnish, dried and pressed to obtain a copper-clad laminate. As shown in Table 1, this copper-clad laminate was excellent in heat resistance, electrical performance, moisture resistance, etc. Furthermore, when this prepreg was left at room temperature for 30 days and then press-molded, it was possible to obtain a copper-clad laminate with exactly the same good appearance as that molded immediately after preparing the prepreg. Moreover, the performance of this copper-clad laminate was as excellent as that of one molded immediately after preparing the prepreg. Example 1 100 gr of 2,4-tolylene diisocyanate,
580g of diglycidyl ether (average molecular weight: about 950, epoxy equivalent: about 480, alcoholic hydroxyl equivalent: about 500) obtained from the reaction of bisphenol A and epoxyhydrin, and 2-methylimidazole.
A varnish with a concentration of 50% was prepared by blending 2gr and 680gr of MEK. Using this varnish, a glass cloth was impregnated, dried and pressed in the same manner as in the examples to obtain a copper-clad laminate. As shown in Table 1, the performance of this copper-clad laminate is that the solder heat resistance after boiling treatment is extremely poor, which indicates that the moisture resistance is poor. Further, when this prepreg was press-molded after being left at room temperature for one day, there was no flow at all and it could not be formed. Comparative Example 2 Diglycidyl ether (average molecular weight approximately 950,
Epoxy equivalent: approx. 480, alcoholic hydroxyl equivalent: approx.
500), 980gr, 2-methylimidazole, 2gr,
A varnish with a concentration of 50% was obtained by blending 1100g of MEK. Using this varnish, a glass cloth was impregnated, dried and pressed in the same manner as in the examples to obtain a copper-clad laminate. As shown in Table 1, the performance of this copper-clad laminate was significantly inferior to the laminate according to the present invention in terms of heat resistance such as bending strength when heated and adhesive strength when heated, and also inferior in electrical performance.

【table】

[Table] As is clear from the above Examples and Comparative Examples, the thermosetting resin composition according to the present invention can provide B-stage compounds such as heat-resistant varnishes, prepregs, and molding materials that are extremely stable at room temperature. In addition to the excellent adhesion and toughness of conventional epoxy cured products, the cured product also has excellent heat resistance, electrical performance, moisture resistance, etc. not found in conventional epoxy resins. Therefore, it is extremely useful in a wide range of applications as a resin for various electrical insulating materials including copper-clad laminates, cast products, structural materials, various molding materials, impregnation, coating, adhesives, etc.

Claims (1)

[Scope of Claims] 1. An epoxy compound having an average molecular weight of 400 to 1000 and having an alcoholic hydroxyl group, which is derived from the reaction between bisphenol A and epichlorohydrin, and an epoxy compound having an isocyanurate ring and containing no urethane group in the molecule. An aromatic amine compound and/or an aromatic amine compound and/or a polyepoxy urethane compound obtained by first reacting the alcoholic hydroxyl group of an epoxy compound with the isocyanate group of a polyisocyanate compound using a polyisocyanate compound having two or more isocyanate groups. Or a thermosetting resin composition characterized by blending dicyandiamide or polycarboxylic acid anhydride. 2. The thermosetting resin according to claim 1, wherein the blending ratio of the epoxy compound and the polyisocyanate compound is 0.5 to 5 equivalents of epoxy group and 0.2 to 3 equivalents of alcoholic hydroxyl group per equivalent of isocyanate group. Composition. 3 The blending ratio of polyepoxy, urethane compound and aromatic amine compound and/or dicyandiamide or polycarboxylic acid anhydride is 1 epoxy group
The thermosetting resin composition according to Claims 1 and 2, which has an amine and/or diamide equivalent or acid anhydride equivalent of 0.1 to 2 equivalents based on the equivalent.