Patent ID: 6017625
Filing Date: 2000-01-25
Classification: D01F,Y10T

Abstract:
A water-absorptive polyurethane fiber obtained by extruding from a nozzle a thermoplastic polyurethane resin composition that is a thermoplastic polyurethane resin obtained by reacting a polyisocyanate compound, a water-soluble polyalkylene ether polyol having a weight-average molecular weight of 2,000-13,000 and an ethylene oxide content of at least 70% by weight, and a chain extender at an equivalent ratio between the equivalent number of OH groups possessed by the water-soluble polyalkylene ether polyol and the chain extender and the equivalent number of NCO groups possessed by the polyisocyanate compound, said equivalent ratio being defined as R ratio (Equation (1)), falling within the range of 1.0 to 1.8, the thermoplastic polyurethane resin composition having a water absorption rate as defined by Equation (2) falling within the range of 200-3,000%, and the extrusion being effected with the thermoplastic polyurethane resin composition held at a temperature not lower than its melting point to be in a molten state: ##EQU3## completely swollen weight being defined as weight when no further weight change occurs during soaking in 25.degree. C. pure water and bone-dry weight being defined as weight when no further weight loss occurs during drying at 100.degree. C.