| abstract |
An object of the present invention is to make it possible to form insoluble solid films of various colors on a zinc surface without using harmful hexavalent chromium and using the same treatment method as conventional reactive chromate. Kind Code: A1 Abstract: (A) one or more members selected from the group consisting of trivalent chromium ions, (B) chlorine, fluorine, sulfate ions, and nitrate ions, and (C) phosphorus oxyacids, oxyacid salts, and anhydrides A method for forming a rust-preventive coating of a metal, which comprises forming a rust-preventive coating with a liquid composition containing at least one of the group consisting of phosphorus compounds. It may contain at least one kind or more, and may further contain at least one kind or more from the group consisting of stabilizers, pigments, dyes, inks, and carbon. [Selection diagram] None |