Photochromic compositions having improved fade rate
US5998520A · kind A · utility
9Cited by
13References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1997 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Jul 2, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L69/005
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A thermoplastic molding composition is disclosed comprising (A) at least one resinous component selected from the group consisting of (i) a homogeneous blend of polycarbonate resin and polycaprolactone and (ii) a copoly(carbonate-lactone) copolymer, and (B) at least one compound selected from a group consisting of benzopyrans, naphthopyrans, spirobenzopyrans, spironaphthopyrans, spirobenzoxazines, spironaphthoxazines, fulgides and fulgimides. The composition which contains the photochromic compound at an amount of 0.01 to 1.0 parts per hundred parts of weight of said (A) exhibits good photochromic properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.