Photochromic material and an optical storage medium using the same
US5360699A · kind A · utility
4Cited by
3References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1993 |
| Grant date | Nov 1, 1994 |
| Priority date | — |
| Expiry date | Apr 23, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/163
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a photochromic material which comprises a spiropyran compound of formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are independently alkyl groups each containing 1 to 30 carbon atoms and Y is a halogen. The photochromic material possesses absorption sensitivity at wavelengths in the length region of about 700 nm which is the oscillation range of a semi-conductor laser device, and possesses higher stability compared with conventional one when it becomes a colored form.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.