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US4701377A Expired / Lapsed US ⏱️ 0.0 years remaining

Polyamide fibers having improved properties, and their production

Assignee: Toyobo Co Ltd
•
Filing: 1986-02-20
•
Granted: 1987-10-20
•
Expires: 2006-02-20
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Abstract

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° C.), an index of birefringence (Δn) (measured after 24 hours under the conditions of 30° C. and 80% relative humidity) of not less than 55×10 -3 and a tenacity of not less than 12.0 g/d, the index of birefringence in section satisfying the following relationship: Δn.sub.A -Δn.sub.B ≧0 (wherein Δn A is the index of birefringence of fiber at the position of r/R=0.9, Δn 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##

Inventors

  • 👤 Kazuo Kurita
  • 👤 Hideaki Ishihara

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 11:47
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/88; D01F6/90; D01F6/58; D01F6/60; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 167 words
A polyamide fiber excellent in strength, comprising at least one of polycapramide, polyhexamethylene adipamide and polytetramethylene adipamide in an amount not less than 60% by weight on the basis of the polyamide fiber, 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° C., an index of birefringence (Δn), measured after 24 hours under the conditions of 30° C. and 80% relative humidity of not less than 55×10 -3 , and a tenacity of not less than 12.0 g/d, the index of birefringence in section of the fiber satisfying the following relationship: Δn.sub.A -Δn.sub.B ≧0 wherein Δn A is the index of birefringence of the fiber at the position of r/R=0.9, Δn B is the index of birefringence of the fiber at the position of r/R=0.0, R is the radius of the fiber section, and the tenacity and the break elongation satisfying the following relationship. ##EQU8##
Claim 2
Dependent Claim 167 words
A polyamide fiber excellent in strength, comprising at least one of polycapramide, polyhexamethylene adipamide and polytetramethylene adipamide in an amount not less than 60% by weight on the basis of the polyamide fiber, 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° C., an index of birefringence (Δn), measured after 24 hours under the conditions of 30° C. and 80% relative humidity of not less than 55×10 -3 , and a tenacity of not less than 12.0 g/d, the index of birefringence in section of the fiber satisfying the following relationship: Δn.sub.A -Δn.sub.B ≧0 wherein Δn A is the index of birefringence of the fiber at the position of r/R=0.9, Δn B is the index of birefringence of the fiber at the position of r/R=0.0, R is the radius of the fiber section, and the tenacity and the break elongation satisfying the following relationship. ##EQU8##
Claim 3
Dependent Claim 27 words
The polyamide fiber according to claim 1, which comprises polycapramide in an amount of not less than 60% by weight of the basis of the polyamide fiber.
Claim 4
Dependent Claim 28 words
The polyamide fiber according to claim 1, which comprises polyhexamethylene adipamide in an amount of not less than 60% by weight on the basis of the polyamide fiber.
Claim 5
Dependent Claim 28 words
The polyamide fiber according to claim 1, which comprises polytetramethylene adipamide in an amount of not less than 60% by weight on the basis of the polyamide fiber.
Claim 6
Dependent Claim 27 words
The polyamide fiber according to claim 1, wherein a fiber long period spacing value at length by small angle X-ray diffraction is not less than 100 Å.
Claim 7
Dependent Claim 31 words
The polyamide fiber according to claim 1, of which the apparent crystal size (ACS) at the plane (0140) obtainable by a broad angle X-ray diffraction is not less than 50 Å.
Claim 8
Dependent Claim 20 words
The polyamide fiber according to claim 1, wherein the relative viscosity is not less than 2.8 and less than 3.5.
Claim 9
Dependent Claim 19 words
The polyamide fiber according to claim 1, wherein the fiber has a denier of not more than 60 denier.

References Cited (Backward Citations)

US3091015A Cited
US2807863A Cited
US3090997A Cited
US3382307A Cited
US3546329A Cited
US3946094A Cited
US4369155A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-10-19 1991-04-20 1991-10-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-10-19 1995-04-20 1995-10-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-10-19 1999-04-20 1999-10-20 $7700.00 Window Closed / Lapsed

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