Method of manufacturing glass substrate for recording medium, glass substrate for recording medium, recording medium and holding jig

A method of manufacturing a glass substrate for a recording medium comprising the step of:

• conducting a chemical strengthening process by which a glass substrate held by a holding jig and the holding jig are immersed in a chemical strengthening solution, and a 1st alkali metal ion on a surface of the glass substrate is substituted by a 2nd alkali metal ion having a larger ion diameter than that of the 1st alkali metal ion contained in the chemical strengthening solution,
• wherein the holding jig comprises a metal film comprising an alkali metal element to cover a surface of the holding jig from the very beginning of the chemical strengthening process.

A holding jig to hold a glass substrate in a chemical strengthening process by which a glass substrate is immersed in a chemical strengthening solution, and a 1St alkali metal ion on a surface of the glass substrate is substituted by a 2nd alkali metal ion having a larger ion diameter than that of the 1st alkali metal ion contained in the chemical strengthening solution,

• the holding jig comprising a member of material made of a metal comprising an alkali metal element.

A holding jig to hold a glass substrate in a chemical strengthening process by which a glass substrate is immersed in a chemical strengthening solution, and a 1st alkali metal ion on a surface of the glass substrate is substituted by a 2nd alkali metal ion having a larger ion diameter than that of the 1st alkali metal ion contained in the chemical strengthening solution,

• the holding jig comprising a metal film comprising an alkali metal element to cover a surface of the holding jig from the very beginning of use of the holding jig in the chemical strengthening process.