| 摘要 |
A thermally stable electrical insulation comprises a layer of cellulosic paper that has been thermally stabilized and a coating thereon of a resin obtained by reacting 9-70% by weight of an ethoxyline resin, 25-90% by weight of shellac and 1-10% by weight of a catalyst or hardener comprising dicyandiamide, melamine or a melamine derivative. The paper may be cyanoethylated paper. The coating resin may be obtained by reacting (i) 38% by weight of delta shellac, 59% by weight of ethoxyline resin and 3% by weight of N.N-diallyl melamine or melamine formaldehyde, or (ii) 78% by weight of shellac, 19% by weight of ethoxyline resin and 3% by weight of dicyandiamide. The coating may be applied from a solution in a common solvent e.g. ethylene glycol monoethyl ether by, for example, spraying or brushing. Specification 992,909 is referred to. |
