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. 13, 2007
Filed:
Aug. 15, 2002
Sadao Sato, Tokyo, JP;
Hideo Kumita, Tokyo, JP;
Kohei Tsuda, Tokyo, JP;
Mitsuo Yamasita, Kanagawa, JP;
Kunio Shiokawa, Kanagawa, JP;
Kenichi Kamiura, Kanagawa, JP;
Kiyoshi Sekiguchi, Kanagawa, JP;
Sadao Sato, Tokyo, JP;
Hideo Kumita, Tokyo, JP;
Kohei Tsuda, Tokyo, JP;
Mitsuo Yamasita, Kanagawa, JP;
Kunio Shiokawa, Kanagawa, JP;
Kenichi Kamiura, Kanagawa, JP;
Kiyoshi Sekiguchi, Kanagawa, JP;
Tokuriki Honten Co. Ltd., Tokyo, JP;
Abstract
Although an Ag—CdO-based material has excellent electric properties such as deposition resistance, arc resistance and low contact resistance, which are required for an electric contact, the discharge standard provision in Japan, EC Directive on Waste from Electrical and Electronic Equipment (WEEE) and the like have been directed toward disuse of Cd, as already known. Thus, the present invention is characterized in that after an atmosphere in a pressured oxidation furnace is replaced with oxygen, the temperature of an internal-oxidative Ag alloy prepared under a condition of a cold roll rate of 50 to 95% is gradually raised from a temperature of 200° C. or less in a pressured oxygen atmosphere with an oxygen pressure of 5 to 50 kg/cmand internal oxidation processing is performed with an upper limit temperature of 700° C., thereby restraining an Ag-rich layer generated on an outermost surface and an oxide-flocculated layer immediately below the Ag-rich layer and uniformly and finely precipitating and dispersing a composite oxide of added elements to a deep part of an internal structure.