Benzopyran compounds
US5429774A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 30, 1994 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Mar 30, 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 having the 2,3 position of a benzofurano or benzothieno group fused to the f, g, or h side of the benzopyran, or a benzo group fused to the f side of the benzopyran, and (i) a substituted or unsubstituted phenyl and (ii) a substituted or unsubstituted benzothienyl or benzofuranyl group attached (via the 2 or 3 position of the group) at the 2 position of the pyran ring. 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.