Synthesis of multifunctional reactive dyes and their application onto wool fabric by inkjet printing

Inkjet printing provides a favourable method for wool printing because of the ability to produce economical short print runs and providing flexibility in print design. This work focused on the synthesis and characterisation of series of novel multifunctional reactive dyes in magenta, blue and yellow hue based on chlorotriazines and chloropyrimidine reactive groups and their modification by: (1) replacing labile chlorine(s) by other labile sulfophenoxy group(s) and (2) replacing the imino bridging group by an aliphatic amino group. This study also focused on the formulation of a set of inks based on parent and modified dyes in magenta, yellow and blue hue, their application onto wool via inkjet printing, and evaluation of percent fixation along with their stability in ink formulations and colour fastness properties. Moreover, the results were also compared with commercially successful Jettex R Inks (DyStar). The research has shown that reactive dyes based on chlorotriazines and chloropyrimidine can be modified by the incorporation of sulfophenoxy group(s) onto the reactive group of the dye. The modified dyes, when inkjet printed onto the wool, were able to react with the wool fibre and show excellent fixation results. The incorporation of more than one reactive group on the dye chromophore has shown an increase in percent fixation compared to dyes with only one reactive group. Moreover, modified inks showed excellent colour fastness to light and wash. Additionally, comparative analysis of modified dye-based inks and commercially successful ‘Jettex R’ inks illustrates that the novel inks are superior in terms of percent fixation and colour fastness properties.