Patent ID: 7273501

Claim:
A method for the manufacture of a highly white and highly moisture absorptive and desorptive fibrous structure which comprises subjecting a fibrous structure comprising a moisture absorptive and desorptive synthetic fiber having a saturated index of moisture absorption of 10% by weight or more at 20° C. and 65% RH blended with another fiber, to reduction with sodium hydrosulfite or with thiourea dioxide and then subjecting the resultant product to an acid treatment with sulfuric acid or nitric acid, wherein said moisture absorptive and desorptive synthetic fiber is a moisture absorptive and desorptive acrylic acid fiber produced by treating an acrylic fiber with a hydrazine compound to introduce crosslinkages, subjecting the fiber to hydrolysis to introduce carboxyl group, and if necessary, introducing a metal carboxylate group by neutralization, wherein said fibrous structure has been prepared by subjecting a fibrous structure which contains 5% by weight or more of said moisture absorptive and desorptive acrylic acid fiber as said moisture absorptive and desorptive synthetic fiber and 30% by weight or more of cotton to a bleaching treatment with hydrogen peroxide or sodium chlorite, and wherein saturated index of water absorption of said moisture absorptive and desorptive synthetic fiber is less than 300% by weight.