Abstract: A chromium(VI)-free, chromium(III)-containing and substantially coherent conversion layer on zinc or zinc alloys presenting, even in the absence of further components such as silicate, cerium, aluminum and borate, a corrosion protection of approx. 100 to 1000 h in the salt spray test according to DIN 50021 SS or ASTM B 117-73 until first attack according to DIN 50961 Chapter 10; being clear, transparent and substantially colorless and presenting multi-colored iridescence; having a layer thickness of approx. 100 nm to 1000 nm; and being hard, adhering well and being resistant to wiping.
Type:
Grant
Filed:
July 19, 2004
Date of Patent:
January 1, 2008
Assignee:
SurTec International GmbH
Inventors:
Patricia Preikschat, Rolf Jansen, Peter Hulser
Abstract: A chromium(VI)-free, chromium(III)-containing and substantially coherent conversion layer on zinc or zinc alloys presenting, even in the absence of further components such as silicate, cerium, aluminum and borate, a corrosion protection of approx. 100 to 1000 h in the salt spray test according to DIN 50021 SS or ASTM B 117-73 until first attack according to DIN 50961 Chapter 10; being clear, transparent and substantially colorless and presenting multi colored iridescence; having a layer thickness of approx. 100 nm to 1000 nm; and being hard, adhering well and being resistant to wiping.
Type:
Grant
Filed:
July 13, 2001
Date of Patent:
September 20, 2005
Assignee:
SurTec International GmbH
Inventors:
Patricia Preikschat, Rolf Jansen, Peter Hulser