Patent · US Expired

Polyamide fibers having improved properties and their production

US4504545A · kind A · utility

11Cited by
5References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 8, 1982
Grant dateMar 12, 1985
Priority date
Expiry dateSep 8, 2002

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 is characterized by being made of a polyamide having a relative viscosity of not 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.), showing an index of birefringence (.DELTA.n) of not less than 50.times.10.sup.-3 and having the following relationship between the break strength and the break elongation: PA1 Break strength (g/d).times.(Break elongation (%)).sup.1/2 .gtoreq.46.0, the index of birefringence in the section of fiber satisfying the following relationship: EQU .DELTA.n.sub.A -.DELTA.n.sub.B .gtoreq.0.5.times.10.sup.-3 (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 section of fiber and r is the distance from the central axis of the section of fiber).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.