Photochromic organic materials
US6034193A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1997 |
| Grant date | Mar 7, 2000 |
| Priority date | — |
| Expiry date | Oct 10, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/23
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention relates to photochromic transparent organic materials presenting an index of refraction of more than 1.55, which are free of optical distortions and are prepared by radical polymerization of a polymerizable composition comprising: PA1 a) 80-95 wt % of at least one monomer represented by the general formula (I): ##STR1## where R=H or CH.sub.3, and m and n are independently 1 or 2; b) 5-20 wt % of at least one aromatic monovinyl monomer represented by the general formula (II): ##STR2## c) an effective quantity of at least one dye that imparts photochromic properties to the material, selected from the groups of spiroxazines, spiropyrans and chromenes; PA1 d) an effective quantity of a chain transfer agent; and PA1 e) an effective quantity of a radical polymerization initiator, characterized in that the chain transfer agent is a linear alkanethiol and the radical polymerization initiator is a diazo compound.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.