| 摘要 |
1,163,999. Coatings. GENERAL ELECTRIC CO. 16 May, 1967 [24 June, 1966], No. 22574/67. Heading B2K. [Also in Division C3] Coatings may be obtained, e.g. on copper wire, glass or steel sheet by heating polyamide acid coatings, e.g. at 30-300‹C to give polyimides. The polyamide acids are obtained by condensing in soln at <40‹C a mixture of a dianhydride selected from, benzophenone tetracarboxylic acid dianhydride, byromellitic dianhydride, ethylene glycol bis (trimellitate) dianhydride or a dianhydride of Formula I with a diamine selected from C 2-8 alkylene diamines m-phenylenediamine or a diamine of formula II in which R is C 1-3 alkylene, CO, O, or SO 2 . The solvent is a mixture of a non- reactive non-hydroxylic organic solvent, e.g. dimethylformamide and at least 35% by wt. of the total solvent of phenol, cresol or mixtures thereof. Reference has been directed by the Comptroller to Specification 1,090,726. |
