| 摘要 |
1434596 Polyamide-acid electrodeposition composition WESTINGHOUSE ELECTRIC CORP 9 April 1973 [19 April 1972] 16824/73 Heading C3R [Also in Division C7] A method of making a non-aqueous, colloidal polyamide-acid electrodeposition composition comprises reacting 1 part (weight) polyamide acid in 29 to 37 parts non-aqueous non-electrolysable organic solvent with 0À8 to 1À2 parts of an imidazole or tertiary amine to form an organic salt and adding the resulting salt solution to 50 to 150 parts of a non-aqueous non-electrolysable organic non-solvent for the salt to provide a colloidal dispersion thereof in the solvent/non- solvent mixture. Finely divided pigments or lubricants may be added to the composition. Numerous suitable aromatic tri- or tetracarboxy compounds and diamines for forming the polyamide acid, tertiary amines, solvents and non-solvents are specified. In specific examples a proprietary solution of polyamideacid in N-methyl pyrrolidone is diluted with dimethyl sulphoxide to the required concentration; triethylamine, 1-methyl imidazole or N,N-dimethyl benzylamine is used to form the salt; and acetone is used as the non-solvent. An 18 wt. per cent solution of a polyamideacid from pyromellitic dianhydride and 3,4<SP>1</SP>- diaminobenzanilide may be used in place of the proprietary solution. The resin is electrodeposited on aluminium, copper, nickel, stainless steel or platinum. |
