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. 18, 1994
Filed:
Aug. 09, 1991
Applicant:
Inventors:
Chung-Yao Chao, Waltham, MA (US);
Lifun Lin, Waltham, MA (US);
Assignee:
Olin Corporation, New Haven, CT (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C25D / ;
U.S. Cl.
CPC ...
205155 ; 205156 ; 205220 ;
Abstract
The present invention relates to a technique for improving the tarnish and oxidation resistance of copper and copper based alloy materials. A chromium-zinc coating is electrolytically applied to copper or copper based alloy surface using a caustic electrolyte solution. The coated material is then rinsed in an aqueous solution containing a phosphate salt of alkali metals or alkaline earth metals, or a borate salt of alkali metals or alkaline earth metals. The pH of the rinse solution is maintained from about 5 to about 12 and preferably from about 7 to about 10.