| 摘要 |
1482167 Laminates MITSUBISHI GAS CHEMICAL CO Inc 18 Dec 1974 [21 Dec 1973] 54685/74 Heading B5N [Also in Division C3] Laminates comprise cured resins obtained from aromatic cyanic acid esters and prepolymers of such esters, by heating them with imidazole or a substituted imidazole as curing catalyst. The cyanic acid esters have the formula where R is a residue derived from benzene, biphenyl or naphthalene or from a compound in which at least two benzene rings are linked by a methylene group, alkyl-substituted methylene group, -O-, -CH 2 OCH 2 -, -S-, -CO-, -SO 2 -, -SO-, -O(PO)O- or -O(PO 2 )O-, or a residue obtained by removing phenolic hydroxyl groups from a novolac or resol resin, an n is 2 to 5. The prepolymers contain triazine rings. The imidazole catalyst has the formula where R<SP>1</SP> is hydrogen, alkyl, benzyl, cyanoalkyl, aminoalkyl or guanaminoalkyl, R<SP>2</SP> is hydrogen, alkyl, cyclohexyl or phenyl and R<SP>4</SP> and R<SP>5</SP> are each hydrogen or alkyl. Also there may be used an adduct formed by co-ordination between an imidazole as above and an aromatic polycarboxylic acid. Other catalysts which are organic metal salts, phenolic compounds or triethylene diamine, also may be present. In examples varnishes are prepared from a prepolymer of 2,2 - bis(4 - cyanatophenyl)- propane dissolved in methyl ethyl ketone, the catalysts being 2-ethyl-4-methyl imidazole, 2- heptadecyl imidazole and the pyromellitic acid adduct of 1-cyanoethyl imidazole and the cocatalysts, where used, being zinc octoate, catechol and triethylene diamine; glass cloth impregnated with one of the varnishes is laminated on copper foil. |
