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:
Mar. 02, 2021
Filed:
Jul. 05, 2016
Denso Corporation, Kariya, JP;
Katsumasa Koeda, Kariya, JP;
Hiroshi Araki, Kariya, JP;
DENSO CORPORATION, Kariya, JP;
Abstract
Provided are a molding step (A) of preparing an alumina molded bodyfrom a molding raw material which contains an alumina raw material powder having an average particle size of 2 μm to 5 μm and a molding additive, and a sintering step (B) of preparing an alumina molded body, which becomes a spark plug insulator, by sintering the alumina molded body. At the sintering step (B), the alumina molded bodyis conveyed to a continuous furnaceprovided with a heating zone Zwhich is heated to 700° C. to 1600° C. by a heating means, followed by introducing oxygen gas to control the heating zone Zto have a high oxygen atmosphere with an oxygen concentration exceeding 20 mol %.