Birefringent transparent film and process for producing the same
US4985531A · kind A · utility
2Cited by
2References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1989 |
| Grant date | Jan 15, 1991 |
| Priority date | — |
| Expiry date | Apr 20, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/3083
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A transparent film having birefringence comprising an amorphous aromatic polymer as a main component is disclosed. The film is produced by uniaxially stretching a film of an amorphous aromatic polymer. The film exhibits high transparency, high heat resistance, and heat distortion resistance, and its birefringence does not undergo changes with time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.