Blended woven or knitted fabrics containing polyerethane elastic fibers and process for the production thereof

Abstract

A blended woven or knitted fabric which contains both highly fusible polyurethane elastic fibers exhibiting a retention of tenacity of 50% or above after the dry heat treatment at 150° C. for 45 s at 100% elongation and a melting point of 180° C. or below and at least one kind of non-elastic yarns and which is produced by fusing the polyurethane elasotomeric fibers to each other or the polyurethane elastic fibers to the non-elastic yarns at the crossover points by dry- or wet-heat setting; and a process for the production thereof.

1 . A blended woven or knit fabric comprising 
 highly fusible polyurethane elastic filaments having at least 50% retention of tenacity after dry heat treatment at 150° C. for 45 seconds at 100% extension and a melting point of 180° C. or below and    at least one kind of non-elastic yarn,    said fabric being obtained by dry or wet heat setting so as to thermally fuse the highly fusible polyurethane elastic filaments to each other or to the non-elastic yarns at crossover points therebetween.    
   
   
       2 . The blended woven or knit fabric of  claim 1  further comprising high-melting polyurethane elastic filaments having a melting point of 200° C. or higher, 
 said fabric being obtained by thermally fusing the highly fusible polyurethane elastic filament with the high-melting polyurethane elastic filaments at crossover points therebetween.    
   
   
       3 . The blended woven or knit fabric of  claim 1  or  2 , wherein the highly fusible polyurethane elastic filaments are melt spun from a polymer obtained by reacting 
 (A) a both end isocyanate-terminated prepolymer prepared by the reaction of a polyol and a diisocyanate with    (B) a both end hydroxy-terminated prepolymer prepared by the reaction of a polyol, a diisocyanate and a low-molecular-weight diol,    wherein at least 50 wt % of the starting polyol is polyether polyol.    
   
   
       4 . A process for manufacturing a blended woven or knit fabric containing polyurethane elastic filaments comprising the steps of 
 forming a woven or knit fabric using highly fusible polyurethane elastic filaments having at least 50% retention of tenacity after dry heat treatment at 150° C. for 45 seconds at 100% extension and a melting point of 180° C. or below and at least one kind of non-elastic yarn and    dry or wet heat setting the woven or knit fabric so as to thermally fuse the highly fusible polyurethane elastic filaments to each other or to the non-elastic yarns at crossover points therebetween.    
   
   
       5 . The blended woven or knit fabric manufacturing process of  claim 4  which additionally uses high-melting polyurethane elastic filaments having a melting point of 200° C. or higher, and thermally fuses the highly fusible polyurethane elastic filaments with the high-melting polyurethane elastic filaments at crossover points therebetween.  
   
   
       6 . Highly fusible polyurethane elastic filaments having at least 50% retention of tenacity after dry heat treatment at 150° C. for 45 seconds at 100% extension and a melting point of 180° C. or below.  
   
   
       7 . The highly fusible polyurethane elastic filaments of  claim 6 , which are melt spun from a polymer obtained by reacting 
 (A) a both end isocyanate-terminated prepolymer prepared by the reaction of a polyol and a diisocyanate with    (B) a both end hydroxy-terminated prepolymer prepared by the reaction of a polyol, a diisocyanate and a low molecular weight diol,    wherein at least 50 wt % of the starting polyol is polyether polyol.    
   
   
       8 . The highly fusible polyurethane elastic filaments of  claim 7 , wherein the polyol has a number-average molecular weight of from 800 to 3,000, the molar ratio of the number of moles of all the diisocyanate to the combined number of moles of all the polyol and all the low-molecular-weight diol for the reactions as a whole is from 1.02 to 1.20, and the amount of isocyanate groups remaining in the just spun filaments is from 0.3 to 1 wt %.  
   
   
       9 . A process for manufacturing highly fusible polyurethane filaments comprising the steps of: 
 synthesizing a spinning polymer by reacting    (A) a both end isocyanate-terminated prepolymer prepared by the reaction of a polyol and a diisocyanate with    (B) a both end hydroxy-terminated prepolymer prepared by the reaction of a polyol, a diisocyanate and a low molecular weight diol, and    melt spinning the polymer without prior solidification,    wherein at least 50 wt % of the starting polyol is polyether polyol.    
   
   
       10 . An article or apparel which is made from the blended woven or knit fabric of  claim 1.