Photochromic composition resistant to fatigue
US4720356A · kind A · utility
169Cited by
8References
19Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 4, 1987 |
| Grant date | Jan 19, 1988 |
| Priority date | — |
| Expiry date | Jun 4, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/73
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An organic photochromic composition comprising spiro [indoline-2,3'-[3H]-naphth [2,1-b] [1,4] oxazine] dye (spirooxazine dye) and unconventional ultraviolet stabilizers. The ultraviolet stabilizers improve the light fatigue resistance of the spirooxazine (S.O.) dye and will not hinder the photocolorability of the photochromic composition. The unconventional ultraviolet stabilizers belong to the class of hindered amine light stabilizers (HALS) and excited state quenchers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.