Pickling/activation solution for the pretreatment of aluminum-steel composites prior to dip tinning

US6194369A · kind A · utility

Assignee

• Th. Goldschmidt. AG · DE

Inventors

• Jan Eberhardt · Mannheim, DE
• Dieter Guhl · Hattingen, DE
• Frank Honselmann · Weingarten, DE

Key dates

• Filing date: Jun 25, 1999
• Grant date: Feb 27, 2001
• Expiry date: Jun 25, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23G1/02
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The invention relates to an aqueous preparation for the pickling and activation of aluminum-steel composites prior to electroless dip tinning. Specifically, the invention provides pickling/activation solutions for the pretreatment of aluminum-steel composites prior to dip tinning which comprise sulfuric acid, hexafluorosilicic acid, at least one wetting agent, at least one transition metal cation and nitrate and/or nitrite ions.