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:
Aug. 03, 1993
Filed:
Jan. 29, 1991
Hirofumi Fukuoka, Annaka, JP;
Mutsuo Shimizu, Annaka, JP;
Hidemitsu Ochiai, Annaka, JP;
Hideaki Shimizu, Gunma, JP;
Masanori Fukuhira, Takasaki, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
Silicon nitride powder is produced in two steps, by supplying metallic silicon powder to a fluidized bed composed of silicon nitride and nitrogen or ammonia gas where primary nitriding reaction is effected until the silicon powder is nitrided to an amount of at least 50% and transferring the nitrided product from the fluidized bed into a moving bed where secondary nitriding reaction is effected for nitriding the unreacted silicon with nitrogen or ammonia gas. This method is adapted for manufacture on a commercial scale because the silicon nitride powder thus obtained is consistent and has a very high degree of nitriding and a minimal variation in quality.