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:
Aug. 02, 1994
Filed:
Sep. 13, 1993
Norio Nakada, Toyama, JP;
Hideo Fukui, Kurobe, JP;
Hatsuo Hirono, Toyama, JP;
Seishiro Ito, Ikoma, JP;
Yoshida Kogyo K.K., Tokyo, JP;
Abstract
A fast and brightly colored oxide film of aluminum which excels in durability and allows no separation of pigment is produced by using an aqueous dispersion of an organic pigment or carbon black finely divided to a size in the range between 3 and 150 nm, forming on a surface of an aluminum member an anodic oxide film containing pores larger in diameter than the ordinary pores, and causing the organic pigment or carbon black to migrate and deposit in the pores of the oxide film by means of electrophoresis. The formation of the anodic oxide film containing the pores larger in diameter than the ordinary pores is accomplished in the first method by subjecting the aluminum member to anodic oxidation at a high voltage in an aqueous solution of acid. In the second method, the anodic oxide film is subjected either to a treatment of immersion in an aqueous solution of at least one acid selected from among phosphoric acid, sulfuric acid, oxalic acid, and sulfamic acid or to a combination treatment of immersion and AC electrolysis repeated in a prescribed number of cycles in the solution, to enlarge the pores in the anodic oxide film.