High strength polyamide yarn

Abstract

Yarns are formed of a copolyamide in an amount of at least 90 wt % with respect to the total weight of the yarn, wherein copolyamide includes (a) at least 95 wt % by weight with respect to the total weight of copolyamide, monomeric units derived from hexamethylene diamine and adipic acid and (b1) cyclic monomeric units derived from a diamine X, and cyclic monomeric units derived from a diacid Y, and/or b2) cyclic monomeric units derived from an amino acid Z. The summed amount of monomeric units derived from X, Y and Z is between 0.1 to 4.5 wt % by weight with respect to the total weight of the copolyamide. The yarns have a tensile strength of at least 80 cN/tex as measured according to ASTM D885-04.

1 . A yarn comprising a copolyamide in an amount of at least 90 wt % with respect to the total weight of the yarn, which copolyamide comprises:
 (a) at least 95 wt % by weight with respect to the total weight of copolyamide, monomeric units derived from hexamethylene diamine and adipic acid and   (b1) cyclic monomeric units derived from a diamine X, and cyclic monomeric units derived from a diacid Y, and/or   (b2) cyclic monomeric units derived from an amino acid Z, wherein   the summed amount of monomeric units derived from X, Y and Z is between 0.1 to 4.5 wt % by weight with respect to the total weight of the copolyamide and wherein   the yarn has a tensile strength of at least 80 cN/tex as measured according to ASTM D885-04.   
     
     
         2 . The yarn according to  claim 1 , comprising at least 95 wt % of the copolyamide with respect to the total weight of the yarn. 
     
     
         3 . The yarn according to  claim 1 , wherein X and Y are present in substantially equal molar amounts. 
     
     
         4 . The yarn according to  claim 1 , wherein the yarn has a tensile strength of at least 85 cN/tex as measured according to ASTM D885-04. 
     
     
         5 . The yarn according to  claim 1 , wherein the summed amount of monomeric units derived from X, Y and Z is between 0.5 to 4.0 wt % with respect to total weight of the copolyamide. 
     
     
         6 . The yarn according to  claim 1 , wherein the diamine X is isophorone diamine and the diacid Y is selected from the group consisting of isophthalic acid and terephthalic acid. 
     
     
         7 . The yarn according to  claim 1 , wherein the yarn has a hot air shrinkage (HAS) of between 1.0 to 7.0% as measured according to ASTM D4974-04 at 177° C. for 2 minutes. 
     
     
         8 . The yarn according to  claim 1 , wherein the yarn has a titer of between 200 to 700 dtex. 
     
     
         9 . The yarn according to  claim 1 , wherein the yarn has a titer of between 300 dtex and 500 dtex and a tenacity of at least 85 cN/tex. 
     
     
         10 . The yarn according to  claim 1 , wherein the yarn has a hot air shrinkage (HAS) of at most 5.0%, a tenacity of at least 85 cN/tex, and a titer of between 300 dtex and 500 dtex. 
     
     
         11 . An air bag fabric comprising the yarn according to  claim 1 .