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. 30, 1997
Filed:
May. 28, 1996
Masahide Mohri, Ibaraki, JP;
Norio Matsuda, Ibaraki, JP;
Shinichiro Tanaka, Ibaraki, JP;
Yoshio Uchida, Ibaraki, JP;
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
An alumina composition, an alumina molded article, prepared from the alumina composition, an alumina ceramic prepared by sintering the alumina molded article, and a process for producing the ceramic; the alumina composition comprising .alpha.-alumina particles having a ratio of the shortest diameter to the longest diameter of from 0.3 to 1; and a size distribution of not more than 5, as expressed in terms of a D.sub.90 /D.sub.10 ratio, wherein D.sub.10 and D.sub.90 represent a cumulative 10% diameter and a cumulative 90% diameter, respectively, of a cumulative distribution depicted from the small diameter side, or comprising .alpha.-alumina particles having a polyhedral shape; a D/H ratio of from 0.5 to 3.0, wherein D represents a maximum particle diameter parallel to a hexagonal lattice plane of a hexagonal close-packed lattice of .alpha.-alumina, and H represents a particle diameter perpendicular to the lattice plane; and a size distribution of not more than 5, as expressed in terms of a D.sub.90 /D.sub.10 ratio, wherein D.sub.10 and D.sub.90 are as defined above.