| 摘要 |
PROBLEM TO BE SOLVED: To provide combined filament yarn of core-sheath type composite with the components of different shrinkage, good in spinnability, causing fibrils when treated with an alkali to reduce weight, and giving cloth by, e.g. knitting or weaving, which is free of pilling and wear-caused blanching. SOLUTION: This combined filament yarn is composed of two groups of fibers having different boiling water shrinkage, with the sheath of the single yarn which constitutes each of the higher-shrinkage yarn (filament yarn X) and lower-shrinkage yarn (filament yarn Y) being composed of two types of polyester components different from each other in solubility in alkali. The yarn has an overall boiling water shrinkage of 40% or less, difference between the filament yarns X and Y in boiling water shrinkage is 5 to 25%, and one the sheath-constituting polyester components which is sparingly soluble in alkali (component A) satisfies the conditions of (a) intrinsic viscosity of 0.6 or more before treatment with moist heat, and (b) intrinsic viscosity sustained at 70 to 92% of the initial level after treatment with moist heat (boiling water) for 30 min. |
