Strengthened, 1.7 index, glass lens
US6255240A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 1999 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | May 21, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S501/903
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The object of the present invention is a novel inorganic glass, which is capable of being strengthened by ionic exchange, and which has a refractive index of between 1.67 and 1.72; said novel glass strengthened on the surface thereof; its method of strengthening; and the corresponding ophthalmic lenses. Said novel glass has the following composition, expressed in wt. % of oxides: SiO.sub.2 33-37 B.sub.2 O.sub.3 7.5-13 with SiO.sub.2 + B.sub.2 O.sub.3 44-48 Li.sub.2 O 5-8 Na.sub.2 O >2.5-7.5 K.sub.2 O 0-2 with Li.sub.2 O + Na.sub.2 O + K.sub.2 O <14 CaO 0-<8 Al.sub.2 O.sub.3 0-6 Nb.sub.2 O.sub.5 8-13 ZrO.sub.2 4-6 TiO.sub.2 5-10 La.sub.2 O.sub.3 12-19 SrO 2-4 As.sub.2 O.sub.3 and/or Sb.sub.2 O.sub.3 0-0.8 (refining agents).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.