Patent ID: 6569498
Filing Date: 2003-05-27
Classification: C23C,Y10T

Abstract:
A method for coating zinc or zinc plated article with a manganese oxide protective coating that is free of chromium comprising coating a cleaned zinc or zinc plated article with a permanganate composition having a PH of about 2.0 to about 9.0 and a permanganate concentration of at least 0.001 moles per liter wherein the permanganate is an alkali metal permanganate with the alkali metal being selected from the group consisting of sodium, potassium, and lithium;maintaining a temperature of the permanganate composition at between 35Â° F. to 180Â° F.; exposing the cleaned zinc or zinc plated article to the permanganate composition for at least 45 seconds; and drying the permanganate coated zinc or zinc plated article wherein the permanganate zinc or zinc plated article can be painted and provide an anti-corrosion paint protected zinc or zinc plated article that will pass the AAMAâ€”605.2-85 dry paint adhesion test.