Process for the preparation of polybenzoxazole and polybenzothiazole filaments and fibers
US5976447A · kind A · utility
5Cited by
9References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1996 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Jun 24, 2016 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F6/74
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A continuous process for heating a polybenzazole or polybenzothiazole filament, which includes the step of heating the filament to a temperature of at least 100.degree. C. but no greater than 290.degree. C. while applying a tension thereto of at least 3.5 grams per denier, which is carried out at a line speed of at least 100 m/minute; and there is no prior or subsequent heating of the fiber to any temperature greater than 300.degree. C. It has been discovered that placing tension on the filament while it is dried increases its tensile modulus without a significant decrease in its tensile strength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.