| 摘要 |
1,228,995. Polyimide coating. GENERAL ELECTRIC CO. 19 April, 1968 [15 May, 1967], No. 18188/68. Heading B2E. [Also in Division C3] Improved resistance to corona discharge is imparted to copper, aluminium, copper-aluminium alloy, polyester and polyvinylformal resin surfaces by coating them with solutions (e.g. in N-methyl-pyrrolidone or N, N-dimethyl-acetamide) of polyamide acids, comprising (1) recurring structural units of the formula: or (2) the above recurring units in the combination with one or more of the following recurring structural units: the carboxyl groups in (a) and (c) being attached to the benzene ring of the phthalic residue in the meta- and/or para-position, and wherein R represents a divalent organic radical, R' represents a divalent hydrocarbon radical, each R" represents the same or different monovalent organic radical, m is an integer of at least 1 and n is an integer greater than 10, removing the solvent by evaporation and heat curing to convert the polyamide acid coating to the corresponding polyimide. |
