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:
Nov. 15, 2010
Hiroaki Ikeda, Tokyo, JP;
Masaru Suzuki, Tokyo, JP;
Kazuna Sasaki, Tokyo, JP;
Yumi Mukai, Tokyo, JP;
Jun Ozawa, Tokyo, JP;
Hiroaki Ikeda, Tokyo, JP;
Masaru Suzuki, Tokyo, JP;
Kazuna Sasaki, Tokyo, JP;
Yumi Mukai, Tokyo, JP;
Jun Ozawa, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
In a method of manufacturing a glass substrate for an information recording medium including a step for chemically strengthening the glass substrate by contacting the glass substrate with chemical strengthening processing liquid containing chemical strengthening salt, concentration of Fe and Cr is 500 ppb or less in said chemical strengthening salt, respectively. The concentration may be detected by the use of an ICP (Inductively Coupled Plasma) emission spectrometry analyzing method or a fluorescent X-ray spectroscopy analyzing method.