Photochromic articles
US5840926A · kind A · utility
19Cited by
9References
23Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1997 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Jul 17, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/23
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A photochromic article that includes a host material and a photochromic amount of a naphthopyran compound, the naphthopyran compound represented by the formula: ##STR1## wherein R.sub.1 ', R.sub.2 ', R.sub.3 ', R.sub.4 ', R.sub.5 ', R.sub.6 ', R.sub.7 ', R.sub.8 ', R.sub.9 ', R.sub.10 ', R.sub.1 ", R.sub.2 ", R.sub.3 ", R.sub.4 ", R.sub.5 ", R.sub.6 ", R.sub.7 ", R.sub.8 ", R.sub.9 ", and R.sub.10 " are each selected from the following group: a stable organic radical, a heterocyclic group, halogen, a nitrogen-substituted group, and a nitrogen-substituted ring compound.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.