Method for insulating conductors

摘要

A metal conductor such as a copper wire is coated with a plurality of layers of a polyimide composition comprising the polymeric condensation product of an aromatic tetracarboxylic acid with an aromatic diamine containing from 6 to 16 carbon atoms or a saturated aliphatic diamine containing up to 6 carbon atoms, and another cured organic composition which is (1) a plain oleoresinous wire enamel, (2) an epoxy enamel comprising a high molecular weight epoxide resin, a fusible condensate of an aldehyde with an organic ammonia derivative, and a polyhydric phenol, or (3) an acrylic enamel applied as an aqueous dispersion of an interpolymer obtained by the polymerisation of acrylonitrile with an alpha-olefinic monocarboxylic acid and an ester of said acid with a 1 to 8 carbon atom saturated aliphatic monohydric alcohol, blended with a dispersion of a heat reactive condensation product of an aldehyde with a phenol or an organic derivative of ammonia such as urea or melamine.ALSO:A metal conductor such as a copper wire is coated with a plurality of layers of a polyimide composition comprising the polymeric condensation product of an aromatic tetracarboxylic acid with an aromatic diamine containing from 6 to 16 carbon atoms or a saturated aliphatic diamine containing up to 6 carbon atoms, and another cured organic composition which is (1) a plain oleoresinous wire enamel, (2) an epoxy enamel comprising a high molecular weight epoxide resin, a fusible condensate of an aldehyde with an organic ammonia derivative, and a polyhydric phenol, or (3) an acrylic enamel applied as an aqueous dispersion of an interpolymer obtained by the polymerization of acrylonitrile with an alpha-olefinic monocarboxylic acid and an ester of said acid with a 1 to 8 carbon atom saturated aliphatic monohydric alcohol, blended with a dispersion of a heat reactive condensation product of an aldehyde with a phenol or an organic derivative of ammonia such as urea or melamine. The oleoresinous enamel may be formed from copal, resin or shellac and a drying oil.