摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass substrate for an information recording medium which reduces surface roughness Ra, is strong against a drop impact and further hardly causes head crash. <P>SOLUTION: A method for manufacturing a glass substrate for an information recording medium by polishing an aluminosilicate glass material comprises a rough polishing step of roughly polishing the aluminosilicate glass material and a precision polishing step of precisely polishing the glass substrate after the rough polishing step. In the rough polishing step, the rough polishing is performed by using an abrasive pad which contains (A) cerium oxide, (B) at least one selected from the group consisting of zirconium silicate, zirconium oxide, manganese oxide, iron oxide, aluminum oxide, silicon carbide and silicon dioxide and (C) urethane and in which the ratio of (A):(B):(C) is 1 to 9 mass%: 5 to 24 mass%: 75 to 90 mass%. <P>COPYRIGHT: (C)2012,JPO&INPIT |