Poly (1,4-cyclohexanedimethylene terephthalate) multifilament yarns for technical applications and production thereof

摘要

A high hydrolysis and aminolysis resistance multifilament yarn composed of a polymer based on poly(1,4-cyclohexanedimethylene terephthalate), wherein at least 85 mol % of the diol-derived groups of the polyester are 1,4-cyclohexanedimethylene groups, characterized by a tenacity of above 40 cN/tex, a dry heat shrinkage S.sub.200 of below 10% and a post hydrolysis or aminolysis treatment strength of at least 85% of the original strength. A process for producing this multifilament yarn comprises maintaining the temperature of the melt at from 295 to 305 C., taking off the filaments at a spinning take-off speed of below 1500 m/min, drawing the spun filaments continuously or batchwise in at least two stages using a defined draw ratio and defined temperatures in every stage, and subjecting the drawn filaments to a setting and relaxing treatment at temperatures above 230 C.