Chemical reaction of reactive dyestuffs with cellulose substitutes

摘要

The covalent-chemical fixation of a reactive dye is coloristically the most important partial step within the full dramaturgy of a reactive cellulose dyeing process. The target of this investigation was a simplified consideration of the dyeing operation by utilization of selected substitutes instead of cellulose. In a physically homogenous aqueous medium some simple aliphatic alcohols were reacted under usual textile conditions with reactive dyes. It was found that primary alcoholic OH-compounds react with all reactive anchor types much better than secondary ones. This may lead to conclusions concerning the most reactive places of cellulose. It was additionally found that poly-alcoholic compounds lead to another increase of reactivity. This may be based on the building of association equilibria formed over π-electron system of a dyestuff and OH-groups of respective cellulose substitutes. Another result was: besides the dye hydrolysis, other undesired side reactions may happen as a covalent-chemical reaction of fresh, reactive dye with dye-hydrolysate as well as with surfactants and anti-dusting agents. Some of these side reactions happen with all anchortypes, other ones just with vinyl-sulfone-types.