Kao Assigned Patent

Kao Corporation, Tokyo, Japan, has been assigned a patent (9,053,736) developed by Doi, Haruhiko, Uchino, Yosuke, and Nishimoto, Kazuhiko, Wakayama, Japan, for a “method for manufacturing an aluminosilicate glass substrate for hard disks.”

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”A method for manufacturing an aluminosilicate glass substrate for a hard disk of the present invention includes polishing an aluminosilicate glass substrate to be polished with a polishing composition that includes silica particles, a polymer having a sulfonic acid group, and water, wherein an adsorption constant of the polymer having the sulfonic acid group on aluminosilicate glass is 1.5 to 5.0 L/g. The polymer having the sulfonic acid group is preferably a polymer having an aromatic ring. The weight average molecular weight of the polymer having the sulfonic acid group is 3000 to 100000.“

The patent application was filed on April 19, 2011 (13/642,410).