Polyamide fabrics with reduced carbon footprint on dyeing

Abstract

A process for dyeing a polyamide yarn or fabric, comprises the steps of: 1) polymerizing a nylon precursor comprising equimolar amounts of an amino groups source and a carboxy groups source, in a mixture further comprising an alfa,omega diamine in an amount corresponding to less than 2% of the amino groups contributed by said amino groups source, and a catalyst, in an amount of less than 100 ppm phosphorus relatively to the nylon precursor, having a formula [R—HP(═O)—O]n-M or R—HP(═O)—OZ, wherein M is a metal preferably selected from the group consisting of sodium, potassium, calcium, barium, and lithium; R is selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, and arylalkyl; n is a whole number corresponding to the valence of the metal; and Z is selected from the group consisting of hydrogen, alkyl, aryl, arylalkyl, and alkyl substituted ammonium cation, with the proviso that R and Z are not simultaneously hydrogen; and R and Z being alkylene when joined to form a ring structure; eventual water molecules in hydrated compounds are not shown; thereby obtaining a polyamide polymer exhibiting a concentration of amine end groups of at least 80 meq/kg; 2) spinning said polyamide polymer into a yarn, and optionally knitting said yarn into a fabric; and 3) dyeing said yarn or said fabric in a dyeing bath comprising a dyestuff in an amount of at least 1% of the weight of said yarn or fabric.

Dependencies are inferred from the claim text.