Patent ID: 6296933
Filing Date: 2001-10-02
Classification: D01F,G01N,Y10T

Abstract:
A hydrophilic fiber which is a fiber characterized in that the ratio of the perimeter occupied by a polyolefin to the whole perimeter of the fiber cross section is 30% or above and the hydrophilic property of the fiber is 30 seconds or below and the retention of the hydrophilic property of the fiber with the lapse of time is 90% or above, which properties are respectively defined as follows:Hydrophilic Property of Fiber:The interior of a pipe made of polymethyl methacrylate and having an inside diameter of 25 mm, an outside diameter of 30 mm and a pipe length of 25 mm is stuffed with 5.0 grams of fibers so as not to protrude the fibers. Said pipe is floated on 1,000 cc of softened water at 30.degree. C. in a container having a caliber of 105 mm .phi. and filled with the water, allowed to stand and once sunk to the bottom. The fibers are then taken out of the interior of the pipe and air-dried at normal temperature. The operations are repeated four times, and the number of seconds required for the pipe from floating on the water to sinking to the bottom of the container is subsequently measured in the fifth operation to provide the hydrophilic property of the fiber.Retention of Hydrophilic Property of Fiber with Lapse of Time:When the hydrophilic property of the fiber before the treatment with lapse of time (at a temperature of 40.degree. C. and a relative humidity of 80% for 30 days) measured according to the above method is a1and the hydrophilic property of the fiber after the treatment with lapse of time is b1, the reciprocal (indicated by %) of b1/a1is defined as the retention of hydrophilic property of the fiber with lapse of time.