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. 12, 2016
Filed:
Nov. 15, 2013
Ohara Inc., Kanagawa, JP;
Kiyoyuki Momono, Kanagawa, JP;
Katsuhiko Yamaguchi, Kanagawa, JP;
Toshitaka Yagi, Kanagawa, JP;
Naoyuki Goto, Kanagawa, JP;
OHARA INC., Kanagawa, JP;
Abstract
It is an object of the present invention to provide a crystallized glass which has various properties required for employing the substrate for information recording medium of the next generation, and also has significantly low specific gravity; and a crystallized glass substrate for information recording medium. A crystallized glass containing, as a crystal phase, one or more selected from RAlOand RTiO(wherein R is one or more selected from Mg and Fe), the crystallized glass comprising the components of SiOof 50% to 70%, AlOof 10% to 26%, TiOof 1 to 15%, MgO of 2.5% to 25%, FeO of 0% to 8%, and ZnO of 0% to less than 2%, expressed in terms of mass percentage on an oxide basis, wherein the value of (AlO+MgO)/SiOis 0.30 or more and 0.65 or less, and a specific gravity is less than 2.63.