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:
Apr. 25, 2006
Filed:
May. 15, 2002
Yoshio Uchida, Tsukuba, JP;
Toshifumi Katsuda, Niihama, JP;
Yoshio Uchida, Tsukuba, JP;
Toshifumi Katsuda, Niihama, JP;
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
α-Alumina powder of fine particles having the primary particle diameters of from 10 nm to 100 nm, and of a high ratio of α-phase and further having capability to provide a sintered body with high density, and a method of manufacturing the α-alumina powder is provided. The method for manufacturing the α-alumina powder comprises a step of mixing an aluminum compound which is the precursor for the corresponding α-alumina and at least one selected from the group consisting of a titanium compound, an iron compound, a chromium compound, and α-alumina, and aluminum nitride, aluminum carbide and a aluminum boride as a seed crystal(s), and a step of calcining the mixture at a temperature of from 600° C. to 1000° C. in the presence of HCl gas in an concentration of 1% by volume to 20% by volume.