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:
Oct. 30, 1984
Filed:
May. 12, 1982
Robert G Hart, Bethlehem, PA (US);
Herbert E Townsend, Center Valley, PA (US);
Bethlehem Steel Corporation, Bethlehem, PA (US);
Abstract
This invention is directed to a method for producing a corrosion-resistant, composite product, such as sheet and strip, having a thin, uniformly black, light-absorptive surface layer thereon, and to the product of such method. The method includes the steps of treating a product having a coating containing both zinc and aluminum, such as galvanized strip, or up to 70% by weight, aluminum, balance essentially zinc coated strip, with an aqueous alkaline solution for a sufficient time to form a zinc-rich surface on said product, which surface is reactive with a blackening bath containing Ni and Sb, and subjecting such treated product to such blackening bath to form said thin, uniform, light-absorptive surface layer on said product. The light-absorptive surface layer has a thickness of at least 80 nm, preferably between about 100-400 nm, and an absorptance greater than about 95% over the solar radiation spectrum.