Photochromic materials having extended pi-conjugated systems and compositions and articles including the same
US8388872B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2012 |
| Grant date | Mar 5, 2013 |
| Priority date | — |
| Expiry date | Feb 21, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31504
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention provides a photochromic material which is an indeno-fused naphthopyran of structural formulas I or II, having a pi-conjugation extending group bonded to the 11-position of the indeno-fused naphthopyran, the pi-conjugation extending group having at least one pendent halo-substituted group bonded thereto. The pi-conjugation extending group extends the pi-conjugation system of said indeno-fused naphthopyran. The 13-position of the indeno-fused naphthopyran is substantially free of spiro-substituents. The invention further provides photochromic materials of specified structure, photochromic compositions, photochromic articles and optical elements that include the photochromic material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.