Organic photochromic materials
US6221284A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1999 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Nov 12, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/041
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention relates to transparent, photochromic or nonphotochromic organic materials, which have a refractive index higher than 1.55 and which are free of optical distortions, consisting of a copolymer of: PA1 (a) 50-90 wt. % of at least one monomer represented by the formula, ##STR1## in which R.dbd.H or CH.sub.3, and m and n are independently 1 or 2; PA1 (b) 10-30 wt. % of at least one aromatic monovinyl monomer represented by formula, ##STR2## R.sub.1.dbd.H or CH.sub.3 ; and PA1 (c) 1-20 wt. % of at least one (meth)acrylic monomer represented by formula, EQU CH.sub.2 =C(R)--COOR' in which R.dbd.H or CH.sub.3 PA1 R' is a straight-chain or branched C.sub.4 to C.sub.16 alkyl radical, an alkylaryl radical, or a polyoxyethoxylated group with formula --(CH.sub.2 --CH.sub.2 O).sub.n R" in which n=1 to 10 and R".dbd.CH.sub.3 or C.sub.2 H.sub.5. Optionally, the photochromic material may contain up to 10 wt. % of at least one photochromic coloring agent to impart desired photochromic properties. The material which may also contain up to 15 wt. % of an aromatic divinyl monomer represented by the formula ##STR3## PA1 where R.sub.1.dbd.H or CH.sub.3., may be polymerized in the presence of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.