| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a glass substrate for a magnetic recording medium, having excellent smoothness of a principal plane, with high productivity and a high yield by preventing defects such as flaws generating prior to a process of polishing a principal plane. <P>SOLUTION: A glass blank for a magnetic recording medium is provided, for forming a glass substrate for a disc-shaped magnetic recording medium having a circular hole in a center portion, and the glass blank has a protective film containing resin on at least one principal plane. A method for manufacturing the glass substrate for a magnetic recording medium includes: a preparation step of a glass blank for a magnetic recording medium; a shape imparting step of processing the glass blank into a disc-shaped glass substrate having a circular hole in a center portion; a principal plane polishing step of polishing the principal plane of the glass substrate; and a cleaning step of cleaning the glass substrate. The preparation step of a glass blank for a magnetic recording medium includes a protective film formation step of forming a protective film containing resin on at least one principal plane of a glass blank to obtain a glass blank for a magnetic recording medium. <P>COPYRIGHT: (C)2013,JPO&INPIT |
