| abstract |
(57) Abstract: In a fiber coloring method for coloring a tryptophan-containing fiber by using an aldehyde compound, a control technique for facilitating darkening, and a method for performing coloring and darkening in an aqueous system. I will provide a. SOLUTION: In a method for coloring a fiber in which a tryptophan-containing fiber is colored with an aldehyde compound, a first step of treating a fiber naturally containing tryptophan or having externally introduced tryptophan with an acid and an aldehyde compound, and A second step of treating the fiber treated in the first step with an oxidizing agent in the presence of an acid. The above color control method, wherein the aromatic aldehyde compound or benzaldehyde derivative is water-soluble. |