Process for the production of biaxially oriented rigid rod heterocyclic liquid crystalline polymer films
US4898924A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1989 |
| Grant date | Feb 6, 1990 |
| Priority date | — |
| Expiry date | Jan 11, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2379/04
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process is disclosed for the production of biaxially oriented liquid crystal films. The process includes: PA1 (i) forming an anisotropic dope from a polymerization solution of rigid rod heterocyclic liquid crystalline polymers such as poly{[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl] 1,4-phenylene}, its cis isomer or mixtures thereof, and poly{[benzo(1,2-d:4,5-d')bisoxazole-2,6-diyl] 1,4-phenylene}, its cis isomer or mixtures thereof, and a solvent such as polyphosphoric acid; PA1 (ii) extruding the dope to form a film; PA1 (iii) imparting biaxial orientation to the film to increase the transverse strength thereof; PA1 (iv) solidifying the biaxially oriented film; and PA1 (v) washing the solidified film to remove the solvent. Also disclosed is a liquid crystal film produced by the above process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.