POLY(TRIMETHYLENE TEREPHTHALATE)FILAMENT YARN AND METHOD FOR PRODUCTION THEREOF

摘要

A polytrimethylene terephthalate (PTT) filament yarn capable of being produced by a high speed spinning method and having a high residual elongation and excellent draw-false twisting processability includes 0.5 to 4.0% by mass of filament elongation enhancing agent particles which are drawn-oriented in the filaments along the longitudinal direction thereof and have a thermal deformation temperature of 40 DEG C or more but less than 105 DEG C, an average particle size D of 0.03 to 0.35 mu m determined in the cross-sections of the filaments and a ratio L/D of the average particle length L in the filament longitudinal direction to the average cross-sectional particle size D of 2 to 20; and the filament yarn exhibits an increase in the residual elongation of 30% or more due to the presence of the filament elongation enhancing agent, a birefringence DELTA n of 0.02 to 0.07, a retaining elongation of 60 to 250% and a thermal stress peak value of 0.18 cN/dtex or less.