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. 18, 1981
Filed:
Sep. 21, 1979
Applicant:
Inventors:
Assignee:
Tokyo Shibaura Electric Co. Ltd., Kawasaki, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C04B / ; C04B / ;
U.S. Cl.
CPC ...
106 732 ; 106 734 ; 106 735 ; 423344 ;
Abstract
Ceramic powder material mainly consists of silicon nitride wherein the content of oxygen combined with generally unavoidable impurities as measured by activation analysis accounts for less than 2% by weight. The above-mentioned ceramic powder material can also be prepared preferably by the method which comprises the step of heating raw ceramic powder material mainly consisting of silicon nitride to 1,400.degree. C. to 1,900.degree. C. in the presence of a separately prepared nonsintered molding of ceramic material or sintered molding of ceramic material having a porosity of at least 10%.