Crystallized glass for substrate of information-recording disk
US5804520A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1997 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Sep 30, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C10/0009
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A crystallized glass for a substrate of an information-recording disk, which has been obtained by melting a glass forming material consisting essentially of, in wt. % as oxide, 55 to 85% of SiO.sub.2, 5 to 20% of Li.sub.2 O, 0 to 10% of K.sub.2 O+Na.sub.2 O, 0 to 10% of MgO, 0 to 20% of CaO, 0 to 10% of SrO, 0 to 10% of BaO, 0 to 10% of ZnO, 0 to 10% of Al.sub.2 O.sub.3, 0 to 15% of B.sub.2 O.sub.3, 0 to 6% of P.sub.2 O.sub.5, 0 to 3% of TiO.sub.2, 0 to 3% of ZrO.sub.2, 0 to 3% of SnO.sub.2 and 0 to 1% of As.sub.2 O.sub.3 +Sb.sub.2 O.sub.3, 0.1 to 10 wt. % of F and 0.1 to 20 wt. % of Cl, molding, vitrifying and crystallizing the material, and which contains at least 0.05% by weight of chlorine after crystallization. The glass forming material may further contain 0 to 10% of Fe.sub.2 O.sub.3, 0 to 10% of Cr.sub.2 O.sub.3, 0 to 10% of NiO, 0 to 10% of V.sub.2 O.sub.5, 0 to 10% of CuO, 0 to 10% of MnO.sub.2, 0 to 10% of MoO.sub.3, the total of Fe.sub.2 O.sub.3 +Cr.sub.2 O.sub.3 +NiO+V.sub.2 O.sub.5 +CuO+MnO.sub.2 +MoO.sub.3 being 0.5 to 10%, and 0 to 3% of CeO.sub.2. The crystallized glass has a microcrystalline structure and surface properties desirable as a substrate material for an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.