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:
Dec. 22, 1987
Filed:
Aug. 22, 1984
Applicant:
Inventors:
Tadao Sato, Sakura, JP;
Toshihiko Ishii, Sakura, JP;
Assignee:
National Institute for Researches in Inorganic Materials, Ibaraki, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01B / ;
U.S. Cl.
CPC ...
423290 ; 501 96 ;
Abstract
A process for preparing rhombohedral system boron nitride, which comprises mixing NaBH.sub.4 with at least an equimolar amount of NH.sub.4 Cl, and heating the resulting mixture in a non-oxidizing atmosphere at a temperature of at least 750.degree. C. and lower than 1000.degree. C. for at least 3 hours.