CHARACTERISTICS OF ALDEHYDE REACTIVE DYES FOR LEATHER DYEING AND RETANNING PROCESS

摘要

Dyeing and re-tanning properties of nine aldehyde reactive dyes synthesized in our previous work were studied using aluminum pretanned wet-white sheep leather as a substrate. Their washing fastness and four dyeing property indexes, i.e., substantivity (S), exhaustion (E), reactivity (R) and fixation (F) were measured. The relationship between the color-matching effect and the relative difference values of the four dyeing property indexes of the combined dyes were investigated, and the simultaneous tanning-dyeing property of reactive dyes with a glutaraldehyde backbone were tested. The results were as follows: (1) The synthesized aldehyde reactive dyes could dye wet-white leather under mild conditions (T = 35-45 degrees C, pH =4.0-6.5) within 1.5 h, and the dyed leather possessed a satisfactory washing-fastness. (2) Reactive dyes with a glutaraldehyde backbone had better dyeing performance than mono-aldehyde reactive dyes. (3) The less the relative difference value of the dyeing property indexes of the combined dyes, the better was the color-matching effect. (4) The tested reactive dyes with a glutaraldehyde backbone increased the T, of wet-white leather to 11-17 degrees C in addition to dyeing it to the corresponding color.