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:
Mar. 01, 1983
Filed:
Feb. 13, 1981
Citizen Watch Co., Ltd., Tokyo, JP;
Abstract
The polyhedral body of aluminum such as a watch case obtained by the inventive method is colored in two different colors on different polyhedral faces demarcated by the ridgeline therebetween with remarkable decisiveness not obtained in the prior art methods. The inventive method utilizes anodization and coloring by dyeing in two steps. A part of the polyhedral faces anodized and colored in a dark color in the first step is ground to expose the bare surface of aluminum, which is then activated by dipping in an aqueous acid solution and again anodized by applying an unconventionally high voltage in an electrolyte bath of a specific composition followed by coloring in a light color decoratively distinguishable from the dark color imparted in the first step coloring. By virtue of the activation treatment of the bare aluminum surface and the unusual conditions in the second anodization, the demarcation between the differently colored polyhedral faces is very decisive and beautiful and the oxide films on both sides of the ridgeline have excellent adhesion and high anti-corrosion resistance.