Benzopyrans
US5411679A · kind A · utility
96Cited by
20References
22Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 13, 1994 |
| Grant date | May 2, 1995 |
| Priority date | — |
| Expiry date | Sep 13, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/23
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Described are novel reversible photochromic benzopyran compounds, examples of which are compounds substituted at the 2 position of the pyran ring and have fused at the benzo portion of the benzopyran a substituted or unsubstituted heterocyclic ring such as a benzothieno or benzofurano group. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel benzopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.