SEA-ISLAND TYPE COMPOSITE FIBER, FIBER STRUCTURE AND POLYESTER COMPOSITION EXCELLENT IN HYGROSCOPICITY

摘要

To provide a sea-island type composite fiber and a polyester composition which are excellent in hygroscopicity and excellent in resistance to oxidation and heat generation.SOLUTION: A sea-island type composite fiber excellent in hygroscopicity having features of (1) to (4) below is provided. (1) a polymer in which an island component 2 has hygroscopicity (2) in the fiber cross section, the ratio (T/R) of the outermost layer thickness 5; T to the fiber diameter 3; R is 0.05 to 0.25 (3) The difference in moisture absorption (ΔMR) after hot water treatment is 2.0 to 10.0% (4) a phenol group content is 16 to 160 mmol/kg. Note that the outermost layer thickness is the difference between the radius of the fiber and the radius of a circumscribed circle 4 connecting the vertices of the island components arranged on the outermost periphery, and represents the thickness of the sea component 1 existing in the outermost layer.SELECTED DRAWING: Figure 1