Abrasion resistant polyester fiber and woven/knitted product

Abstract

Provided is an abrasion-resistant polyester fiber, which has, in particular, a strength within a specific range, an elongation within a specific range and a Young's modulus falling within a specific range in a specific elongation range on a stress-strain curve, to improve the abrasion resistance of a woven/knitted product for clothing using, in particular, a fine size polyester fiber. The polyester fiber is an abrasion-resistant polyester fiber comprising ethylene terephthalate as a main repeating unit, characterized by satisfying the following requirements: (1) the fineness being from 8 dtex to 200 dtex inclusive; (2) the single yarn fineness being from 1.0 dtex to 4.0 dtex inclusive; (3) the breaking strength being 3.5 cN/dtex or greater; (4) the breaking elongation being from 20% to 50% inclusive; and (5) the minimum differential Young's modulus being 20 cN/dtex or less in an elongation range of from 2% to 5% inclusive on a stress-strain curve of the fiber.

1 . A abrasion resistant polyester fiber comprising ethylene terephthalate in 95% by mole or more, as a repeating unit, characterized by satisfying the following requirements (1) to (5):
 (1) a fineness is 8 dtex to 200 dtex inclusive;   (2) a single yarn fineness is 1.0 dtex to 4.0 dtex inclusive;   (3) a breaking strength is 3.5 cN/dtex or higher;   (4) a breaking elongation is 20% to 50% inclusive; and   (5) a minimum differential Young's modulus of region having an elongation of 2% to 5% inclusive in a 1.5 stress-strain curve of the fiber, is 20 cN/dtex or lower.   
     
     
         2 . The polyester fiber according to claim.  1 , characterized by further satisfying the following requirement (6):
 (6) a yarn abrasion strength is 0.5 time/dtex or more.   
     
     
         3 . The polyester fiber according to  claim 1 , characterized by further satisfying the following requirement (7):
 (7) a limiting viscosity is 0.70 dl/g to 1.30 dl/g inclusive.   
     
     
         4 . The polyester fiber according to any one of  claims 1  to  3 , characterized by further satisfying the following requirement (8):
 (8) a crystallinity is 60% to 90% inclusive, and an orientation is 0.70 to 0.92 inclusive. 
 
     
     
         5 . An abrasion resistant woven product comprising the polyester fiber according to any one of  claims 1  to  4 . 
     
     
         6 . The abrasion resistant woven product according to  claim 5 , wherein the woven product has a weight decrease ratio of 5% or less for 30 thousand times in the Martindale abrasion test. 
     
     
         7 . The abrasion resistant woven product according to  claim 5  or  6 , wherein the woven product has a woven product texture of ripstop taffeta. 
     
     
         8 . An abrasion resistant knitted product comprising the polyester fiber according to any one of  claims 1  to  4 . 
     
     
         9 . The abrasion resistant knitted product according to  claim 8 , wherein mass per unit area is 80 to 350 g/m 2  inclusive. 
     
     
         10 . A method for producing the abrasion resistant polyester fiber according to any one of  claims 1  to  4 , comprising the following steps of:
 melt spinning a polyester having a limiting viscosity of 0.70 dl/g to 1.30 dl/g inclusive; 
 performing drawing treatment under a draw ratio of 65% to 85% inclusive of the limiting draw ratio; and 
 performing relaxation heat treatment at a heat treatment temperature of 120° C. to 220° C., inclusive, and a relaxation ratio of 5% to 15% inclusive. 
 
     
     
         11 . The method for producing the abrasion resistant polyester fiber according to  claim 10 , wherein after drawing treatment and winding once, then the relaxation heat treatment is performed. 
     
     
         12 . The method for producing the abrasion resistant polyester fiber according to  claim 10 , wherein the relaxation heat treatment is performed subsequent to drawing treatment without winding once. 
     
     
         13 . The method for producing the abrasion resistant woven product according to any one of  claims 5  to  7 , wherein the relaxation heat treatment is performed, in setting at a dyeing processing step. 
     
     
         14 . The method for producing the abrasion resistant woven product according to  claim 13 , wherein the relaxation heat treatment of the woven product, comprising the polyester fiber false twisted at 180 to 200° C. inclusive, is performed at temperature higher than false twisting temperature. 
     
     
         15 . The method for producing the abrasion resistant knitted product according to  claim 8  or  9 , wherein the relaxation heat treatment is performed in setting at a dyeing processing step. 
     
     
         16 . The method for producing the abrasion resistant knitted product according to  claim 15 , wherein the relaxation heat treatment of the knitted product, comprising the polyester fiber false twisted at 180 to 200° C. inclusive, is performed at temperature equal, to or higher than false twisting temperature.