Photochromic tetraphenyl naphthodipyrans
US5464567A · kind A · utility
80Cited by
4References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1994 |
| Grant date | Nov 7, 1995 |
| Priority date | — |
| Expiry date | Apr 8, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/23
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Described are novel reversible photochromic naphthopyran compounds which have two phenyl moieties adjacent to each oxygen of each pyran ring. The substituents on each pair of phenyl moieties mirror one another when the phenyl groups are substituted. The naphthodipyrans are prepared from .beta.,.beta.-dihydroxynaphthalene compounds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.