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. 18, 1989
Filed:
Apr. 24, 1987
Hiroaki Tanji, Tokyo, JP;
Masaharu Suzuki, Machida, JP;
Kenji Nomura, Machida, JP;
Shojiro Watanabe, Machida, JP;
Takashi Kawasaki, Machida, JP;
Denki Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A pyrolytic boron nitride article of the invention has uniform structure and has 0.5 or less nodules/cm.sup.2 in average all through the overall surface of the article and 2 or less nodules in any portion of the unit square centimeter on the surface of the article. The pyrolytic boron nitride article is produced by depositing boron nitride through a vapor phase, using a boron halide gas and an ammonia gas as the starting materials. Upon production, the ammonia gas or a gas mixture containing the ammonia gas is not contacted directly with graphite at 300.degree. to 1850.degree. C.