| 20090162703 | Glass Substrate for Information Recording Medium, and Method of Manufacturing Glass Substrate for Magnetic Recording Medium and Information Recording Medium - Not only chemical durability of a glass substrate for an information recording medium is improved, but also no deformation of the substrate and no alteration of substrate characteristics are to be made. A chemical treatment layer formed on the glass substrate surface is made thicker toward a large surface roughness portion of the glass substrate, prior to being subjected to a chemical treatment, from a small surface roughness portion of the glass substrate. Layer thickness D of the resulting chemical treatment layer preferably satisfies the following inequality (1) in view of acquisition of chemical durability. | 06-25-2009 |
