Photochromic naphthopyrans
US5238981A · kind A · utility
172Cited by
14References
22Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 24, 1992 |
| Grant date | Aug 24, 1993 |
| Priority date | — |
| Expiry date | Feb 24, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D311/92
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Described are novel reversible photochromic naphthopyran compounds substituted at the number eight carbon atom on the naphtho portion of the naphthopyran ring with, for example, a methoxy 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 naphthopyran compounds are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.