Salt-free dyeing method for active dye

Abstract

The invention relates to a salt-free dyeing method for an active dye, belonging to the field of printing and dyeing of active dyes. The salt-free dyeing method for the active dye comprises a modification treatment step and a dyeing step, wherein the modification treatment step comprises the following sub-steps of: (1) alkalinizing cotton fibers; (2) impregnating the alkalinized cotton fibers obtained by the sub-step (1) in an active intermediate solution for cotton fiber modification; and (3) impregnating the modified alkalinized cotton fibers obtained by the sub-step (2) in a carboxylic acid group-containing cationic reagent solution for cotton fiber cationic modification. By the alkalinization of the cotton fibers and the introduction of a plurality of carboxyl groups and amino groups, the reactivity of the cotton fibers is improved, and further cationization and reaction with the active dye are facilitated.

Description

technical field [0001] The invention relates to a salt-free dyeing method of reactive dyes, belonging to the field of reactive dye printing and dyeing. Background technique [0002] Reactive dyes have the characteristics of bright colors, complete chromatograms, simple dyeing process, and excellent color fastness. They are widely used in the dyeing of cotton, linen and their blended fibers. When dyeing with reactive dyes, a large amount of inorganic salts (such as sodium chloride and sodium sulfate) need to be added. The amount of salt is 30-100g / L. It is difficult and costly to treat dyeing wastewater with high salt content. If it is directly discharged, it will change the water quality of rivers and lakes. , leading to salinization of the soil around the lake, seriously affecting the growth of crops. In addition, reactive dyeing has the problem of low color fixation rate, and the dye utilization rate is usually only 50% to 70%, resulting in the waste of a large amount of ...

AI Technical Summary

Problems solved by technology

[0004] Although the cationization of cotton fibers can promote the adsorption of dyes, it is also found that during the process of chemical modification of cotton fibers to introduce cationic groups, a large number of active hydroxyl groups on cotton fibers, especially primary alcohol hydroxyl groups with high reactivity, react with cationic reagents. The color fixing process of reactive dyes, that is, the reaction between the active groups of reactive dyes and the hydroxyl groups of fibers is affected, thus affecting the effect of salt-free dyeing

In addition, the application of high-molecular-weight cationic reagents also brings about the problem that dyes are difficult to penetrate into the fiber, which affects the fixation and color fastness of reactive dyes on cotton fibers.

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