| 摘要 |
PURPOSE:To obtain the titled yarn having improved thermal dimensional stability, by extruding a polymer having an ethylene terephthalate unit, etc. in a molten state, cooling it, drawing it just before solidification with subjecting it to necking deformation, making it into specific orientated and crystallized yarn, heating, and drawing it. CONSTITUTION:A polymer consisting of an ethylene terephthalate unit, etc., having >=0.75 intrinsic viscosity is subjected to melt spinning, cooled by cooling air at 10-120 deg.C at 0.2-1m/sec. wind velocity, subjected to necking deformation just before solidification and drawn, to give spun yarn having diffraction points caused by crystallization observable by X-ray diffraction of wide angle, A=[apparent crystal size of (010)/ apparent crystal size of (100)] of 0.8-1.2, showing four points interference caused by >=250Angstrom long period structure by X-ray scattering image of small angle. This yarn is then drawn at >=125 deg.C at 1.5-2 times, to give the desired yarn having >=1.3 A, 0.01Angstrom larger face interval of (010) than that of undrawn yarn, satisfying relationship betwen elongation E4.5 at 4.5g/d load after heat treatment at 240 deg.C for 2 minimutes and free heat shrinkage ratio S150 at 150 deg.C shown by the formula on condition that 2.0<=E4.5<=7.0.
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