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. 17, 2009
Filed:
Jun. 20, 2007
Hiroshi Usui, Chiyoda-ku, JP;
Osamu Miyahara, Chiyoda-ku, JP;
Katsuaki Miyatani, Chiyoda-ku, JP;
Yoshinori Kon, Chiyoda-ku, JP;
Iori Yoshida, Chiyoda-ku, JP;
Hiroshi Usui, Chiyoda-ku, JP;
Osamu Miyahara, Chiyoda-ku, JP;
Katsuaki Miyatani, Chiyoda-ku, JP;
Yoshinori Kon, Chiyoda-ku, JP;
Iori Yoshida, Chiyoda-ku, JP;
Asahi Glass Company, Limited, Tokyo, JP;
Abstract
A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing at least one water-soluble polymer selected from the group consisting of a water-soluble organic polymer having amino groups, a water-soluble organic polymer having amine salt groups and a water-soluble organic polymer having quaternary ammonium salt groups, and colloidal silica.