Patent ID: 8309177

Claim:
A method of treating a zinc-galvanized metal surface, which has been chemically passivated, the treatment providing increased resistance to corrosion and improved adherence to a subsequently applied organic coating comprising: a) contacting a chromium passivated, zinc-galvanized metal surface with a coating solution bath comprising: 1) from about 1 to about 10 parts per thousand, based on fluorine content, of an inorganic acid or ion that contains fluorine; 2) at least 0.5 parts per thousand, based on transition metal cation content, of an oxide and/or a salt of nickel; and 3) optionally, from about 0 to about 3.0 grams per liter of a polymer selected from the group consisting of polyacrylic acid, polymethacrylic acid, and C1 to C8 alkanol esters thereof; wherein the pH of the solution is from about 2.0 to 3.6 and the temperature of the solution is at least 60° C.; and thereafter b) sealing the treated surface.