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:
Nov. 05, 1991
Filed:
Mar. 27, 1990
Hagio Tsuyoshi, Tosu, JP;
Kazuo Kobayashi, Tosu, JP;
Hisayoshi Yoshida, Ogoori, JP;
Ichitaro Ogawa, Tosu, JP;
Hiroshi Harada, Omuta, JP;
Hiroaki Yasunaga, Omuta, JP;
Hiroshi Nishikawa, Omuta, JP;
Agency of Industrial Science and Technology, Tokyo, JP;
Denki Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A pressureless sintered body of boron nitride contains more than 95 wt% of boron nitride. The pressureless sintered body hexagonal of boron nitride has a density of not less than 1.10 g/cm.sup.3 and a bending strength of not less than 300 kg/cm.sup.2. A process of producing the pressureless sintered body of boron nitride comprises pulverizing powders of starting feed boron nitride so that a specific surface area of each of the powders is two times or more than that of the starting feed boron nitride powder, molding the thus pulverized powders to obtain a pre-molded body and sintering the pre-molded body at a temperature of not less than 1400.degree. C. under atmospheric pressure and under non-oxidative atmosphere.