Compositions having low birefringence
US6323291A · kind A · utility
68Cited by
6References
26Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1996 |
| Grant date | Nov 27, 2001 |
| Priority date | — |
| Expiry date | Apr 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/2534
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A thermoplastic molding composition suitable for the preparation of articles having low birefringence is disclosed. Accordingly, the composition contains polycarbonate and a polyester copolymer based on cyclohexane-dimethanol, ethylene glycol and phthalic acid. The invention resides in the findings that the incorporation of a polycarbonate resin having a melt flow index greater than 18 g/10 minutes impart to the composition low birefringence values. The composition is suitable for the preparation of optical storage media, including compact discs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.