| 摘要 |
A polyester filament yarn produced by a melt-spinning a mixture of a polyester resin with 0.4 to 4.0 weight % of filament elongation-enhancing agent particles and taking up the filament yarn at a speed of 2500 to 8000 m/minutes, having an increase in residual elongation of 50 % or more and exhibiting an improved winding performance, wherein the filament elongation-enhancing agent particles satisfies the requirements (a), (b) and (c): (a) the particles have a thermal deformation temperature of 105 to 130 DEG C, (b) provided that the polyester filaments have a non-hollow circular cross section, the distribution density of the particles is maximized in an annular area between two concentric circles around the center of the cross section, of which the two concentric circles have radiuses corresponding to 1/3 and 2/3 of the radius of the cross section, respectively; and (c) the number of the particles appearing on the filament surfaces is 15 particles/100 mu m<2> or less. |
