Process for producing glass substrate for information recording medium
US6119483A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1997 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Dec 29, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/8404
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An object of the present invention is to prevent the dhesion of particles such as fine iron powders onto a glass substrate upon the production of a glass substrate for an information recording medium. To attain the above object, any one of the following means is adopted: (1) at least one of the production, inspection, packing and filling steps of the glass substrate for an information recording medium is carried out under a clean atmosphere which does not permit the adhesion of particles; (2) at least a wall surface of a chemical reinforcement tank containing a chemical reinforcement liquid therein and/or said retaining means which is contact with the chemical reinforcement liquid is formed of a stainless alloy having corrosion resistance in a high-temperature region as high as the heating temperature of the chemical reinforcement liquid; (3) a means for trapping fine particles existing in the chemical reinforcement liquid used in the chemical reinforcement step is provided; and (4) the glass substrate is washed with hydrochloric acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.