Agc Inc.

Asahi Glass Company, Limited

Toru Momose

Hirofumi Yamamoto

Osamu Sato

Nobuhiko Takeshita

Tetsuya Nakashima

Katsuaki Miyatani

Masahiko Tamura

A method of producing a glass article includes holding a carrier having a circular shape, in which a glass substrate having a circular shape is retained, with an upper surface plate and a lower surface plate; and polishing the glass substrate by rotating the carrier with respect to the upper surface plate and the lower surface plate, to obtain the glass article. The glass substrate is disposed in the carrier such that, in a top plan view, a center of the carrier is included in a region of the glass substrate, and a center of the glass substrate is shifted from the center of the carrier.

Glass article and method of producing glass article

The present invention relates to a method for manufacturing a glass substrate for information recording medium, the method including: a lapping step of lapping a circular glass plate made of an alkali aluminosilicate glass; and a subsequent cerium oxide polishing step of polishing the circular glass plate with a slurry containing a cerium oxide abrasive, in which a difference (SiO&#x2212;AlO) obtained by subtracting an AlOcontent from an SiOcontent in the alkali aluminosilicate glass is 62% by mole or less; and in which the method further includes: subsequently to the cerium oxide polishing step, a cleaning step of cleaning the circular glass plate with a cleaning liquid having a sulfuric acid concentration of 20% by mass or more and 80% by mass or less and a hydrogen peroxide concentration of 1% by mass or more and 10% by mass or less at a liquid temperature of 50&#xb0; C. or higher and 100&#xb0; C. or lower, and after the cleaning step, a finish polishing step of polishing a main surface of the circular glass plate with a slurry containing a colloidal silica abrasive.

Glass substrate for information recording medium and method for manufacturing the same, and magnetic recording medium

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Tokyo, Japan

Toru Momose