The dyeing rate behavior (K/S‐t curve) of the intact jute fiber was investigated under the 2,5‐diaminotoluene (dAT)/2,4‐diaminophenoxy ethanol (dAPE) dyeing system with 75ml/L or 5ml/L of hydrogen peroxide(H
2O
2). Although the amount of dye uptake was dependent on the dye intermediate concentration, the fastest was the dyeing rate at pH7, followed in order by pH9 and pH5 at both H
2O
2 concentrations of bath solution. This order was the same order as the effect of pH on the rate of oxidative‐dye formation in the reaction solution containing the dissolved oxygen. However, the K/S‐t curve obtained by dyeing at pH9 in H
2O
2 solution of 5ml/L showed a sigmoid (S‐shaped) curve which is convex downward in the initial dyeing time. Furthermore, if the jute fibers pretreated with H
2O
2 were dyed under the same dyeing conditions, its amount of dye uptake was lower than that of the intact jute fiber. In particular, when dyed with the solution of pH9, and the lowest amount of dye uptake is obtained and its dyeing rate drew a downwardly convex curve. This result suggested that the oxidative decomposition reaction of jute fiber components, such as a pigment substance, might affect the oxidative dye concentration of the fiber surface which determines the dye uptake into internal fibers. When observing the time course of coloring phenomenon on the H
2O
2 treated jute fiber bundles in the oxidative dyeing bath with 75ml/L of H
2O
2, the coloring degree on the fiber surface was found to be thinner than that in the bulk solution. This observation indicates that the oxidative decomposition of some oxidation dyes generated in the solution/fiber interface occurs simultaneously at the fiber surface layer. Consequently, all of the oxidative dyeing behavior of the intact and the H
2O
2 treated jute fiber could explain satisfactorily by taking into account the decomposition reaction of one or both of the fiber component and the oxidation dye.
抄録全体を表示