High index photochromic glasses
US4891336A · kind A · utility
20Cited by
6References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 9, 1988 |
| Grant date | Jan 2, 1990 |
| Priority date | — |
| Expiry date | Dec 9, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C3/11
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention is related to transparent, fast darkening and fading photochromic glasses. The glasses contain SiO.sub.2, B.sub.2 O.sub.3, Al.sub.2 O.sub.3, ZrO.sub.2, Li.sub.2 O, Na.sub.2 O, K.sub.2 O, MgO, CaO, SrO, BaO, ZnO, La.sub.2 O.sub.3, Nb.sub.2 O.sub.5, TiO.sub.2 as base glass components, Ag, Br, Cl, CuO as photochromic elements, with, optionally, Sb.sub.2 O.sub.3, As.sub.2 O.sub.3, and SnO.sub.2 as colorants to impart a brown color at darkening. The glasses have a refractive index greater than 1.585, an Abbe number greater than 42, and a density lower than about 2.80 g/cm.sup.3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.