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:
Jan. 08, 2013
Filed:
Jun. 03, 2008
Takashi Murata, Otsu, JP;
Hiroki Yamazaki, Otsu, JP;
Takashi Murata, Otsu, JP;
Hiroki Yamazaki, Otsu, JP;
Nippon Electric Glass Co., Ltd., Otsu-shi, Shiga, JP;
Abstract
An object of the invention is to obtain a glass substrate having high mechanical strength by reconciling suitability for ion exchange and devitrification proof in a glass. The strengthened glass substrate of the invention is a strengthened glass substrate having a compression stress layer in the surface thereof, the glass substrate having a glass composition including, in terms of % by mass, 40-70% of SiO, 12-25% of AlO, 0-10% of BO, 0-8% of LiO, 6-15% of NaO, 0-10% of KO, 13-20% of LiO+NaO+KO, 0-3.9% of MgO, 0-5% of CaO, 0-5% of ZnO, 0-6% of ZrO, and 0-5% of SrO+BaO, the value of (MgO+ZrO+ZnO)/(MgO+ZrO+ZnO+AlO) in terms of mass proportion being from 0.25 to 0.45. The above-mentioned strengthened glass can be produced by melting raw glass materials mixed together so as to result in the given glass composition, forming the melt into a sheet by an overflow downdraw process, and then conducting an ion exchange treatment to form a compression stress layer in the glass sheet surface.