| 摘要 |
<p>1427063 Electro-phoretic deposition WESTINGHOUSE ELECTRIC CORP 9 April 1973 [19 April 1972] 16825/73 Heading C7B A metallic conductor, e.g. Al, Cu, Ni or steel wire, ribbon or foil, is coated by continuously passing it as anode near a cathode in a bath of a conducting non-aqueous polyamic acid electrodeposition composition comprising acid salt reaction product of a polyamic acid and a N- containing base within a non-aqueous organic solvent mixture comprising solvent for the acid and non-electrolyzable non-solvent for the salt, and the coating is cured to form a polyimide film on the conductor. As shown, the conductor may be fed from unwind reel 1 around inslated pulleys 4 through the bath 5 of a colloidal dispersion or pure solution of the salt, having pH 8-10, to pass charged positively at 2 through a circular cathode or between two connected cathode plates 6 in the bath, then through curing oven 8, e.g. heated initially at 250-325‹F and finally at 600-875‹F. The backs of the cathode plates may be coated with polyethylene or polyimide resin 7. The current density is preferably 2-10 mA/sq in of electrode surface and conductor surface opposite. The N-containing base may be an amine or imidazole and the non-solvent for the salt may be a ketone; many examples of the compounds are specified. The solvent for the acid may be an N, N-dialkyl-carboxylamide, dimethyl sulphoxide and/or pyridine. Aromatic polyamic acid polymers are specified. Pigments and lubricants may be added to the bath. The conductor may be the ribbon of a low inductance resistor element for a circuit breaker.</p> |
