Phosphating process for zinc-plated metals

US4497668A · kind A · utility

Assignee

• Gerhard Collardin GmbH · DE

Inventors

• Raschad Mady · Frechen, DE
• Winand Hanelt · Düren, DE
• Roland Morlock · Bergheim, DE
• Dieter Geruhn · Werl, DE
• Lutz Leyhe · Witten, DE
• Jobst H. Meyer zu Bexten · Soest, DE
• Franz Ricke · Schwelm, DE

Key dates

• Filing date: Nov 25, 1983
• Grant date: Feb 5, 1985
• Expiry date: Nov 25, 2003

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C22/12
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A process for phosphating zinc-plated metal articles, particularly electrolytically zinc-plated steel sheets, by treatment thereof for a short period with an acidic phosphating solution which, in addition to zinc and phosphate ions, can contain other metal cations and/or anions of oxygen-containing acids having an accelerating effect, wherein the phosphating solution has a content of Zn.sup.2+ -cations of between about 1 and 2.5 g/l, a free acid content in the range from 0.8 to 3 points, and the acid ratio of total acid to free acid in the range from 5 to 10. The phosphating treatment is carried out for a period of time not in excess of about 5 seconds.