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:
Jul. 09, 2019
Filed:
Mar. 01, 2017
Ngk Insulators, Ltd., Nagoya, JP;
Morimichi Watanabe, Nagoya, JP;
Hiroshi Fukui, Obu, JP;
Kei Sato, Tokai, JP;
Tsutomu Nanataki, Toyoake, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
96 parts by mass of a γ-alumina powder, 4 parts by mass of a an AlFpowder, and 0.17 parts by mass of an α-alumina powder as a seed crystal were mixed by a pot mill. The purities of each raw material were evaluated, and it was found that the mass ratio of each impurity element other than Al, O, F, H, C, and S was 10 ppm or less. In a high-purity alumina-made sagger having a purity of 99.9 percent by mass, 300 g of the obtained mixed powder was received, and after a high-purity alumina-made lid having a purity of 99.9 percent by mass was placed on the sagger, a heat treatment was perforated at 900° C. for 3 hours in an electric furnace in an air flow atmosphere, so that an alumina powder was obtained. The value of AlFmass/container volume was 0.016 g/cm.