Spinnable polyester based on modified polyethylene terephthalate and aliphatic dicarboxylic acids

Abstract

There are described a spinnable polyester for producing fully oriented polyester yarn by high speed spinning based on polyethylene terephthalate modified by incorporation of aliphatic dicarboxylic acids as cocondensed units and which may additionally contain up to 5% by weight of further additaments customary for modifying polyethylene terephthalate, wherein modifying aliphatic dicarboxylic acids present as cocodensed units have in total from 4 to 10 carbon atoms and are present in such an amount that the glass transition temperature of the polyester is 70.degree. C. or below, the recrystallization temperature of the polyester is 180.degree. C. or below and the heat of fusion of the polyester, determined by DSC measurement, is 30 J/g or below, a polyester yarn producible therefrom by high speed spinning, which has a novel combination of high strength, high modulus and enhanced shrinkage capacity, and a process for producing this yarn.

Dependencies are inferred from the claim text.