The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 13, 2004
Filed:
Mar. 10, 2000
Peter Kuhm, Hilden, DE;
Michael L. Sienkowski, Warren, MI (US);
Gerald J. Cormier, Oxford, MI (US);
Matthias Hamacher, Hurth, DE;
Jurgen Geke, Dusseldorf, DE;
Volkhard Enke, Leverkusen, DE;
Jan-Willem Brouwer, Willich, DE;
Hubert Venschott, Pforzheim, DE;
Henkel Kommanditgesellschaft auf Aktien, Duesseldorf, DE;
Abstract
In a process for the chemical pretreatment before painting of composite metal structures that contain aluminum or aluminum alloy portions together with steel, galvanized steel and/or alloy-galvanized steel portions, in a first step the metal structure is treated with a zinc phosphating solution that forms a surface-covering crystalline zinc phosphate layer on steel and on galvanized or alloy-galvanized steel, but without forming a zinc phosphate layer on the aluminum portions, and then in a second step the metal structure is brought into contact with a treatment solution that does not excessively dissolve the crystalline zinc phosphate layer on steel, galvanized and/or alloy-galvanized steel, but forms a conversion layer on the aluminum portions.