Process for coagulation and washing of polybenzazole fibers
US5393478A · kind A · utility
18Cited by
18References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 20, 1993 |
| Grant date | Feb 28, 1995 |
| Priority date | — |
| Expiry date | Aug 20, 2013 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F6/74
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Fibers spun from polybenzazole dopes can quickly be washed to remove polyphosphoric acid by a combination of initially washing with an acidic liquid and second washing with a hot leaching fluid at at least about 60. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.