Structure Design, Synthesis And Properties Of Environment-friendly Deep Shade Reactive Dyes

Reactive black and reactive deep red dyes are two kinds of the most important and largest production for the commercial reactive dyes, but the current productes are not satisfying. Up to now, the fixation ratio of most of the reactive black dyes were only about 60%, which means about 40% dyes were wasted, bringing a heavy burden to the environment. And the application of the deep red reactive dyes was limited by their poor wet fastness. Then high fixation of reactive black dyes and good wet fastness of reactive deep red dyes were the problems deserved for solution. The subjects were studied in this paper by dye molecular structure modification and commercialization based on the supramolecular chemistry theory.The structure-property relationships of the commercial reactive black dyes show that, compatibility of the component dyes is very important for the properties of the reactive black dyes, and the fixation of the reactive black dyes is mainly determined by the navy component. Most of the current commercial reactive black dyes are consist of C.I. Reactive Black 5, whose fixation ratio is 62%, causing a low fixation of 60-65% of the commercial reactive black dyes. Then, novel reactive dyes with high fixation should be synthesized to improve the fixation of reactive black dyes. As to improve the fixation, the substantivity of the reactive navy dye should be enhanced. Some novel navy dyes were synthesized by modifying the molecular structure of C.I. Reactive Black 5, and the relationships between the structure and properties of the navy dyes were studied. The results show that, extention of the conjugated system of the novel dyes enhanced their substantivity and the fixation ratio a lot, and the build up property can be improved by commercialization with addition agent. The fixation ratios of several of the newly synthesized dyes were up to 80%, and the application properties were satisfying, several dyes can be used for formulating reactive black dyes with high fixation.Several reactive deep black dyes were formulated by the novel reactive navy dyes and proper red and orange components after commercialization. Compare with the commercial products, the fixation ratios increased by 15-20%, but the depth of the waste water reduced by 60-70%, the novel reactive deep black dyes have very good environmental benefits. The build up and wet fastness properties of the novel reactive deep black dyes were satisfying as well.A range of bisazo red reactive dyes has been synthesized using 2-amino-5-naphthol-7-sul- fonic acid and its derivatives as the coupling components. The dye structures were confirmed by ¹HNMR, ¹³CNMR and MS spectra. And the dyeing properties and wash fastness on cotton fiber have been examined and rationalized in terms of the dye structure. It was found that the dyes exist in the quinoid-hydrazone form at the naphthol side, and the azo form at the naphthylamine side. The synthesized dyes are electron donor-accepter chromogens, and the color of the dyes can be predict by the perturbation molecular orbital theory. Hydrophobic groups increase the substantivity and fixation on cotton fiber, but decrease the build-up and migration properties. The planarity of the dye molecule also influences the dyeing properties; steric effects of the substitutes on the dye molecule will decrease the substantivity, and affect the other properties. The washing factor defined in this paper can directly indicate the wash fastness of the dyes. Four red reactive dyes with both high fixation and good wash fastness were synthesized by molecular structure modifying and commercialization, their fixations were up to 80%, and compare with commercial ones, they provide better build up and wet fastness properties, and the other application properties were satisfying as well.