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:
Sep. 12, 1995
Filed:
Jan. 28, 1993
Applicant:
Inventors:
Motohiko Yoshizumi, Omiya, JP;
Hisae Hirako, Omiya, JP;
Assignee:
Mitsubishi Materials Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09C / ;
U.S. Cl.
CPC ...
51308 ; 501127 ; 501153 ; 423600 ; 423625 ; 423628 ;
Abstract
A process for production of a fine alpha-alumina powder having a specific surface area of not smaller than 10 m.sup.2 /g and superior polishing characteristics is provided, the process comprising heat-treating a mixture of gamma-alumina powder and silica at a temperature at which gamma-alumina is converted to alpha-alumina in the presence of silica, wherein the mixture contains not more than about 10 wt % of silica, based on the weight of the gamma-alumina.