Process for the drying and heat-treatment of polybenzazole films
US5445779A · kind A · utility
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18References
9Claims
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Key dates
| Filing date | Jan 14, 1994 |
| Grant date | Aug 29, 1995 |
| Priority date | — |
| Expiry date | Jan 14, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2379/04
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A simplified and more efficient process is described for drying (and heat-treating) a lyotropic polybenzazole film in which the film is constrained in only the machine direction during drying (and heat-treating). The amount of stretching in the transverse direction the film undergoes prior to it being coagulated can be increased to compensate for the relaxation of the film during the drying process and the lack of stretching during the heat-treating process. Films made in this manner have acceptable finished properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.