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:
Dec. 25, 1984
Filed:
Nov. 30, 1983
Karl-Heinz Gottwald, Erftstadt, DE;
Reinhard Opitz, Duren, DE;
Henkel Kommanditgesellschaft auf Aktien, Duesseldorf, DE;
Abstract
A process for phosphating metal surfaces, particularly iron, steel and zinc-plated steel, by treating them with aqueous, acidic zinc phosphate baths at only moderately elevated temperatures in the range of from 22.degree. to 38.degree. C. The baths used have 2 to 6 g/l of Zn; 4 to 23 g/l of PO.sub.4.sup.3- ; a free acid content of 0.05 to 0.4 points; and a pH-value of 3.0 to 4.0. The ratio of Zn to PO.sub.4.sup.3- is preferably in the range from 1:2 to 1:11. The baths can advantageously contain nickel-(II)-ions, with a nickel content not exceeding a Zn:Ni ratio of 1:0.5. This process gives iron-containing zinc phosphate layers having an iron content of from 5 to 20% by weight and is particularly useful for pretreatment for subsequent cathodic electro-dip-lacquering.