Polyamide fibers having improved properties, and their production
US4701377A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1986 |
| Grant date | Oct 20, 1987 |
| Priority date | — |
| Expiry date | Feb 20, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2913
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A polyamide fiber excellent in strength, which comprises at least one of polycapramide, polyhexamethylene adipamide and polytetramethylene adipamide in an amount of not less than 60% by weight on the basis of the polyamide fiber and which is characterized by having a relative viscosity of not less than 2.3 and less than 3.5 (measured on a 96% by weight sulfuric acid solution having a polyamide concentration of 10 mg/ml at 20.degree. C.), an index of birefringence (.DELTA.n) (measured after 24 hours under the conditions of 30.degree. C. and 80% relative humidity) of not less than 55.times.10.sup.-3 and a tenacity of not less than 12.0 g/d, the index of birefringence in section satisfying the following relationship: EQU .DELTA.n.sub.A -.DELTA.n.sub.B .gtoreq.0 (wherein .DELTA.n.sub.A is the index of birefringence of fiber at the position of r/R=0.9, .DELTA.n.sub.B is the index of birefringence of fiber at the position of r/R=0.0, R is the radius of the fiber section and r is the distance from the central axis of the fiber section) and the tenacity and the break elongation satisfying the following relationship: ##EQU1##
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.