Process for producing meta-aromatic polyamide fiber
US6569987B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 2001 |
| Grant date | May 27, 2003 |
| Priority date | — |
| Expiry date | Jun 21, 2021 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F6/605
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
To produce meta aramid filaments having a good quality from a polymer solution of a meta aramid produced by a solution polymerization method, with high efficiency, (1) a meta aramid is prepared by polymerization-reacting a aromatic meta-diamine with a aromatic meta-dicarboxylic acid chloride in a polar organic solvent; (2) hydrogen chloride contained in the resultant polymer solution is neutralized with a neutralizing agent containing an alkali metal hydroxide which can react with hydrogen chloride to produce a salt thereof insoluble in the polymerization solvent; (3) the salt deposited from the polymer solution is removed by filtration; (4) the resultant polymer solution is mixed with water and a polar organic amide solvent to prepare a spinning solution; (5) the resultant meta aramid spinning solution is directly extruded in the form of filamentary streams into an aqueous coagulation liquid, to coagulate the extruded filamentary streams of the polymer solution into the form of filaments; (6) the coagulated filaments are immersed in water to remove the salt and the solvent from the filaments; and (7) the water-washed filaments are drawn and heat-treated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.