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:
Apr. 16, 2013
Filed:
Mar. 24, 2010
Shigeru Yamagata, Tokyo, JP;
Tomomi Usui, Tokyo, JP;
Shigeru Yamagata, Tokyo, JP;
Tomomi Usui, Tokyo, JP;
Shin-Etsu Quartz Products Co., Ltd., Tokyo, JP;
Abstract
A method for producing a silica container comprising: forming a preliminarily molded substrate, wherein a first powdered raw material is fed to an inner wall of an outer frame having aspiration holes while rotating the outer frame; forming a preliminarily molded intermediate layer, wherein a second powdered raw material added with an aluminum compound or a crystal nucleating agent as an additive is fed to an inner wall of the preliminarily molded substrate; and forming an inner layer, wherein the preliminarily molded substrate and the preliminarily molded intermediate layer are degassed by aspiration from a peripheral side with heating from an inside thereby forming a substrate and an intermediate layer, and while a third powdered raw material having a high silica purity is spread from inside the substrate having the formed intermediate layer with heating from the inside thereby forming an inner layer on an inner surface of the intermediate layer.