Patent ID: 6287394
Filing Date: 2001-09-11
Classification: C09D,C23C

Abstract:
A method for treating a surface of zinc or of an alloy of zinc and aluminum to form a polymeric film which provides passivation to prevent corrosion of the zinc or the alloy of zinc and aluminum, said method comprising applying to said surface an aqueous solution having a pH of below 3 and comprising a complex from at least one species of metal oxo ion in conjunction with at least one species of hetero ion, the metal oxo ion being selected from the group consisting of molybdate, tungstate and vanadate; the hetero ion being selected from the group consisting of phosphorous (V), aluminum (III), silicon (IV), manganese (II), manganese (IV), zirconium (IV), titanium (IV), tin (IV), cerium (III) and nickel (II); wherein the ratio of hetero to metal ion in the complex is between 1:5 and 1:14; and(2) applying to said surface a film forming acid tolerant resin compatible with the selected ions.