Copolymer fibers and yarns and processes for making same
US9790622B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2016 |
| Grant date | Oct 17, 2017 |
| Priority date | — |
| Expiry date | Sep 30, 2036 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD10B2401/063
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The present invention concerns methods for obtaining high-tenacity aramid yarn, wherein the yarn is made of a copolymer obtained from a mixture of monomers comprising 5-(6)-amino-2-(p-aminophenyl)benzimidazole, an aromatic para-diamine, and an aromatic para-diacid; the method comprising: a) spinning said copolymer from an inorganic acid solvent to produce the aramid yarn; b) washing said yarn with a basic aqueous solution for at least 5 seconds; and c) heating said yarn; wherein the yarn is heated in at least two process steps, characterized in that (i) in a first step the yarn is heated at a temperature of 200 to 360° C. at a tension of at least 0.2 cN/dtex, followed by (ii) a second step wherein the yarn is heated at a temperature of 370 to 500° C. at a tension of less than 1 cN/dtex. In some embodiments, the yarn has an effective polymer cation to sulfur content molar ratio of at least 0.3. In some embodiments, the yarn has a hydrolytic strength retention of the yarn is greater than 60%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.