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:
Nov. 09, 1993
Filed:
Dec. 16, 1992
Applicant:
Inventors:
Norifumi Hatano, Tokyo, JP;
Akihiko Hasebe, Tokyo, JP;
Kazuyuki Oyama, Tokyo, JP;
Katsuya Yamamoto, Yokohama, JP;
Assignees:
Nihon Parkerizing Co. Ltd., Tokyo, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C25D / ;
U.S. Cl.
CPC ...
205149 ; 205196 ; 205286 ; 205319 ;
Abstract
A colorless chromate coating film is formed on a bright aluminum wheel by subjecting the surface of an aluminum wheel to a cathodic electrolytic treatment in an acidic aqueous solution containing not less than 2 g/l of hexavalent chromium ions, 20 to 2,000 ppm of sulfate ions, 10 to 400 ppm of fluorine (F) as fluoride and not less than 20 ppm of zirconium ions at a pH of 0.6 to 1.7 at a current density of 0.5 to 15 A/dm.sup.2 for at least 30 seconds, thereby forming a coating film with a chromium coating amount of 50 to 250 mg/m.sup.2.