Chromium free treatment before coating metal surfaces

US5026440A · kind A · utility

Assignee

• Gerhard Collardin GmbH · DE

Inventors

• Cornelia Finnenthal · Pulheim, DE
• Wolf-Achim Roland · Solingen, DE
• Roland Morlock · Bergheim, DE

Key dates

• Filing date: Aug 24, 1989
• Grant date: Jun 25, 1991
• Expiry date: Aug 24, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C22/83
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The adhesion of, and corrosion protection provided by, organic surface coatings to underlying metal can be significantly improved if the degreased, etched, and pickled metal surfaces to be coated are first treated with an aqueous solution and/or dispersion of aluminum-zirconium complexes, which are obtainable as the reaction-product of a chelated aluminum component, an organo-functional ligand component, and a zirconium oxyhalide component, with the organo-functional ligand being chemically bonded to the chelated aluminum unit and the zirconium unit in the complex, and are subsequently treated with dilute aqueous solutions, emulsions, and/or dispersions of one or more inorganic and/or organic film-forming materials prior to coating the surfaces with conventional organic surface coatings.