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:
May. 01, 2012
Filed:
Mar. 16, 2010
Jun Endo, Chiyoda-ku, JP;
Tatsuo Nagashima, Chiyoda-ku, JP;
Tetsuya Nakashima, Chiyoda-ku, JP;
Manuel Diaz Reyes, Chiyoda-ku, JP;
Jun Endo, Chiyoda-ku, JP;
Tatsuo Nagashima, Chiyoda-ku, JP;
Tetsuya Nakashima, Chiyoda-ku, JP;
Manuel Diaz Reyes, Chiyoda-ku, JP;
Asahi Glass Company, Limited, Tokyo, JP;
Abstract
A glass for an information recording medium substrate, which comprises, as represented by mol % based on the following oxides, from 61 to 72% of SiO, from 3 to 11% of AlO, from 0 to 14.3% of LiO, from 0 to 22% of NaO, from 0 to 22% of KO, from 4 to 13% of MgO, from 0 to 6% of TiOand from 0 to 5% of ZrO, provided that the total content of LiO, NaO and KO (RO) is from 10 to 22%, and (a) the ratio of the content of LiO to RO (LiO/RO) is at most 0.52, (b) the ratio of the content of NaO to RO (NaO/RO) is at least 0.35, or (c) the ratio of the content of KO to RO (KO/RO) is at least 0.45.