Reinforced glass substrate
US5780371A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1996 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Aug 19, 2016 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA47B2200/0094
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention relates to glass substrates intended for use as a support in data storage units, reinforced by surface ion exchanges and whose matrix comprises the constituents given hereinafter in the following weight proportions: ______________________________________ SiO.sub.2 45-65% Al.sub.2 O.sub.3 0-20% B.sub.2 O.sub.3 0-5% Na.sub.2 O 4-12% K.sub.2 O 3.5-12% MgO 0-8% CaO 0-13% ZrO.sub.2 0-20% ______________________________________ the sum of the oxides SiO.sub.2, Al.sub.2 O.sub.3 and ZrO.sub.2 remaining equal to or below 70%, said composition optionally incorporating the oxides BaO and/or SrO in proportions 11%.ltoreq.MgO+CaO+BaO+SrO.ltoreq.24% and the alkaline oxides are introduced in the following weight percentages 0.22%.ltoreq.Na.sub.2 O/Na.sub.2 O+K.sub.2 O.ltoreq.0.60.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.