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. 08, 1991
Filed:
Jul. 28, 1989
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B37B / ;
U.S. Cl.
CPC ...
428409 ; 428457 ; 428913 ; 428 64 ; 428 65 ; 204 33 ; 204 58 ; 346 / ; 3461351 ; 369288 ;
Abstract
A body, particularly a thin layer, of aluminium or aluminium alloy is given a corrosion-resistant bright dense barrier-type protective layer. The layer has a thickness in the range 50 to 500 nm and comprises aluminium oxide and a chelate complex of aluminium and at least one organic chelating compound. The layer is formed by contacting the surface with a solution of the chelating compound of pH 2 to 7 and, optionally, performing oxidative electrolysis.