Glasses with very high index of refraction and low density
US5288669A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1993 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Feb 12, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S501/901
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention relates to glasses exhibiting refractive indices higher than 1.880, Abbe numbers of at least 29, densities lower than 4.1, good chemical durability and stability against devitrification, and an integrated transmission over the range of 380-800 nm at a thickness of 10 mm greater than 79%, the glasses consisting essentially, expressed in terms of weight percent on the oxide basis, of ______________________________________ SiO.sub.2 5-8 B.sub.2 O.sub.3 15-21 ZrO.sub.2 3-10 TiO.sub.2 7-17 Nb.sub.2 O.sub.5 20.5-26 ZrO.sub.2 + TiO.sub.2 + Nb.sub.2 O.sub.5 29-45 La.sub.2 O.sub.3 19-32 Y.sub.2 O.sub.3 0-9 CaO 8-16 SrO 0-5 BaO 0-5 MgO 0-5 CaO + SrO + BaO + MgO 8-16 ZnO 0-5 Li.sub.2 O 0-2 Na.sub.2 O 0-2 K.sub.2 O 0-2 Li.sub.2 O + Na.sub.2 O + K.sub.2 O 0-2. ______________________________________
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.