| 摘要 |
A process for coating electrically conductive objects comprising A. immersing said object as the anode of an electric current in an aqueous polyurethane dispersion prepared by (1) forming a polyurethane solution by reacting an organic polyisocyanate in the presence of an organic solvent with (a) an acrylic ester diol having a molecular weight of between 146 and 3,000; (b) an organic polyhydroxyl compound other than (a) having a molecular weight between 400 and 5,000 selected from the group consisting of polyester, polyols, polyether polyols, polycarbonates, polylactones, and mixtures thereof; and (c) a chain extender selected from the group consisting of diols, triols, diamines, aminoalcohols, having a molecular weight between 62 and 400, water, and mixtures thereof; (2) forming an anionic polyurethane addition product by reacting said polyurethane solution with a mercaptocarboxylic acid salt in the presence of a solvent; (3) adding water; and (4) removing the organic solvent, and B. passing an electric current between the anode and a cathode which is also dispersed in said dispersion, and C. irradiating said object with ultraviolet radiation or electron rays. The process can be used for coating metals such as iron, steel and aluminum.
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