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:
Sep. 03, 2019
Filed:
Jun. 16, 2015
Ube Industries, Ltd., Ube-shi, JP;
Ube Industries, Ltd., , JP;
Abstract
A silicon nitride powder having a specific surface area of 4.0 to 9.0 m/g, a β phase proportion of less than 40 mass %, and an oxygen content of 0.20 to 0.95 mass %, wherein a frequency distribution curve obtained by measuring a volume-based particle size distribution by a laser diffraction scattering method has two peaks, peak tops of the peaks are present respectively at 0.4 to 0.7 μm and 1.5 to 3.0 μm, a ratio of frequencies of the peak tops ((frequency of the peak top in a particle diameter range of 0.4 to 0.7 μm)/(frequency of the peak top in a particle diameter range of 1.5 to 3.0 μm)) is 0.5 to 1.5, and a ratio D50/D(μm/μm) of a median diameter D50 (μm) determined by the measurement of particle size distribution to a specific surface area-equivalent diameter D(μm) calculated from the specific surface area is 3.5 or more.