Dyeing Behavior of Wool Fibers in Oxidation Dyeing System with Ternary Mixture of Dye Intermediates

Coloration behaviors of the wool fabric dyed with p-aminophenol(pAP)/p-phenylenediamine(pPDA)/ pamino-o-cresol(pA0C) mixed oxidation dyeing system were investigated by varying the dyeing conditions, such as the composition ratio of their dye intermediate, the concentration of hydrogen peroxide and the bath ratio of dyeing system. In the case of pAP/pPDA/pA0C (1: 1: 2) dyeing system of pH10 with the addition of 90m1/L hydrogen peroxide, the chromaticity in the a*b* diagram varied to draw a hairpin curve, which showed that the color of dyed sample turned a dark reddish orange having lower saturation through a dull orange having the highest saturation from a dull yellowishorange, with the increase in dyeing time. As a result of dyeing under various conditions, it has been found that (1) the varied composition ratio of dye intermediates affects significantly the difference in the hue angle and the chroma between the fabrics dyed for 5 min and 120 min, and that (2) the coloration of the fabrics in the 1: 1: 2 dyeing system of pH10 with the addition of 5m1/L hydrogen peroxide is dependent on the uptake of the pPDA/pA0C coupling dyes which generate preferentially even at low concentrations of hydrogen peroxide, and that (3) the uptake of pPDA/pA0C coupling dye increases more than that of pAP/pA0C coupling dye with decreasing in the bath ratio of the dyeing system.