Patent ID: 8357208

Claim:
A method for producing a modified wool fiber, comprising: step 1 of pre-oxidizing a cystine bond (—S—S— bond) present in an epidermal cell of an wool fiber so that the cystine bond is in a low oxidation state, step 2 of oxidizing with ozone the pre-oxidized —S—S— bond so that the —S—S— bond is in at least one high oxidation state selected from di-, tri-, and tetra-oxidation states, and step 3 of reductively cleaving the —S—S— bond that is in a high oxidation state, wherein the method imparts shrink resistance and pilling resistance to the wool fiber, wherein an area shrinkage of the wool fiber is 10% or less at a 10-hour value, and wherein in the step 2, ozone is microdispersed as a bubble in an aqueous solution that comprises an anionic sulfate surfactant having a C 8-18 alkyl group, and the wool fiber is contacted with the ozone, the anionic sulfate surfactant is present in an amount ranging from 0.01 to 0.1 wt% in the aqueous solution, the bubble of the ozone has a diameter ranging from 0.5 to 3μm, and the ozone is supplied in an apparent amount ranging from 1.5 to 4% owf to the wool fiber.