Polyurethane urea elastic fiber and production method therefor

Abstract

An object of the present invention is to provide a polyurethane urea elastic fiber whose physical properties do not change much over time and which retains its initial mechanical properties, and a method for obtaining this fiber by modifying the molecular chain and ends of the polyurethane urea polymer. Another object of the present invention is to provide a polyurethane urea elastic fiber whose use can improve inventory management and fiber processing condition management, and which can be used to obtain a fabric with stable physical properties and qualities, and to provide a method for producing this fiber. The present invention is a polyurethane urea elastic fiber comprising: polyurethane urea polymer A having a molecular chain using a polymer diol, a diisocyanate, and an organic amine as starting materials, and having a primary or secondary amino group on at least one end; and polyurethane urea polymer B using a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, and containing an amide bond, wherein the polyurethane urea elastic fiber contains primary or secondary amino end groups in the range of 0.1 meq or more and 20 meq or less per kilogram of polyurethane urea elastic fiber.

1 . A polyurethane urea elastic fiber comprising:
 polyurethane urea polymer A having a molecular chain using a polymer diol, a diisocyanate, and an organic amine as starting materials, and having a primary or secondary amino group on at least one end; and   polyurethane urea polymer B using a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, and containing an amide bond, wherein the polyurethane urea elastic fiber contains primary or secondary amino end groups in the range of 0.1 meq or more and 20 meq or less per kilogram of polyurethane urea elastic fiber.   
     
     
         2 . A polyurethane urea elastic fiber according to  claim 1 , wherein the polyurethane urea elastic fiber has an amine bond total in the range of 0.1 meq or more and 10 meq or less per kilogram of polyurethane urea elastic fiber. 
     
     
         3 . A polyurethane urea elastic fiber according to  claim 1 or 2 , wherein the molecular weight of the structural portion derived from the organic carboxylic acid is 100 or more and 300 or less. 
     
     
         4 . A method for producing a polyurethane urea elastic fiber, the method comprising:
 dry spinning a spinning solution containing polyurethane urea polymer A having a molecular chain using a polymer diol, a diisocyanate, and an organic amine as starting materials, and having an amino group on at least one end; and   polyurethane urea polymer B using a polymer diol, a diisocyanate, an organic amine, and an organic carboxylic acid as starting materials, and containing an amide bond, wherein the amount of primary or secondary amino groups in polyurethane urea polymer A and polyurethane urea polymer B contained in the spinning solution is in the range of 0.1 meq or more and 25 meq or less per kilogram.   
     
     
         5 . A method for producing a polyurethane urea elastic fiber according to  claim 4 , the method comprising:
 preparing solution a containing polyurethane urea polymer A having a molecular chain using a polymer diol, a diisocyanate, and an organic amine as starting materials, and having a primary or secondary amino group on at least one end;   adding an organic carboxylic acid-based compound to solution a to react with some of the polyurethane urea polymer A, produce polyurethane urea polymer B having a molecular chain containing an amide bond, and prepare a spinning solution containing polyurethane urea polymer A and polyurethane urea polymer B; and   dry spinning the spinning solution.   
     
     
         6 . A method for producing a polyurethane urea elastic fiber according to  claim 4 , the method comprising:
 preparing solution a containing polyurethane urea polymer A having a molecular chain using a polymer diol, a diisocyanate, and an organic amine as starting materials, and having a primary or secondary amino group on at least one end;   separating some of solution a and adding an organic carboxylic acid compound to react with polyurethane urea polymer A, produce polyurethane urea polymer B having a molecular chain containing an amide bond, and prepare solution b;   mixing solution a and solution b together to prepare a spinning solution containing polyurethane urea polymer A and polyurethane urea polymer B; and   dry spinning the spinning solution.   
     
     
         7 . A method for producing a polyurethane urea elastic fiber according to any of  claims 4 to 6 , wherein a cyclic acid anhydride having a molecular weight of 100 or more and 300 or less is used as the organic carboxylic acid or the organic carboxylic acid-based compound.