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. 21, 2023
Filed:
Jun. 04, 2019
Shin-etsu Quartz Products Co., Ltd., Tokyo, JP;
Yuji Baba, Takefu, JP;
SHIN-ETSU QUARTZ PRODUCTS CO., LTD., Tokyo, JP;
Abstract
A quartz glass crucible including a bottom portion, a curved portion, and a straight body portion, where the quartz glass crucible includes an outer layer including opaque quartz glass containing bubbles therein, and an inner layer including transparent quartz glass, the outer layer includes a plurality of layers in a part of the straight body portion, out of the plurality of layers, one layer having a devitrification spot number of 50/cmor more and 70/cmor less when the quartz glass crucible is heated at 1600° C. for 24 hours, and a layer positioned inwards of the devitrifiable layer in a thickness direction of the quartz glass crucible is a low devitrification layer having a spot number of 2/cmor less when the quartz glass crucible is heated at 1600° C. for 24 hours. This provides a quartz glass crucible suppressed from deformation due to heating and excessive progression of devitrification.