Active sulfur black dye and preparation method thereof

Abstract

The invention discloses a preparation method of an active sulfur black dye. The preparation method comprises the steps of (1) adding sulfur black and sodium sulfide to water, and reacting to obtain a sulfur black leuco body solution; (2) adding ice cakes to caustic soda, then adding chloroacetic acid for reaction to obtain a sodium chloroacetate solution; (3) adding the sodium chloroacetate solution to the sulfur black leuco body solution to obtain a sulfur black carboxylation liquid; and (4) adding 20%-30% of sodium pyrosulfite solution to the sulfur black carboxylation liquid, and drying and crushing to obtain the active sulfur black dye after reaction is ended. Hydrophilic groups such as carboxylic acid groups or sulfonic acid groups are introduced to the active sulfur black dye prepared by the method to serve as modified groups so that the degree of dyeing and the dyeing property are increased. The active sulfur black dye can be applied to all cellulosic fibers and blending products of the cellulosic fibers, paper and leather, and particularly can show excellent application performance in the leather dyeing. The invention also discloses the active sulfur black dye prepared by the method.

Description

technical field [0001] The invention relates to a reactive sulfur black dye and a preparation method thereof, belonging to the technical field of sulfur dye modification. Background technique [0002] Sulfur dyes are dyes produced by the interaction of certain organic aromatic compounds such as amines or phenolic compounds with sulfur or polysulfides, because the molecules contain sulfur bonds (monosulfur bonds, disulfide bonds or polysulfide bonds), So called sulfur dyes. Sulfur dyes are insoluble in water. Sodium sulfide (commonly known as sodium sulfide) is used to reduce it to soluble leucosome sodium salt when dyeing. The leucosome sodium salt has a good affinity for cellulose and protein fibers and can be used to dye fibers. After dyeing, it will be oxidized and restored to become an insoluble dye and fixed on the fiber. [0003] At present, the production process of sulfur dyes is relatively simple, the cost is low, the raw materials are simple and easy to obtain, t...

AI Technical Summary

Problems solved by technology

The water-soluble sulfur dye that this method makes has water-solubility and carboxyl reactivity concurrently, can improve the dyeing rate of dyestuff, yet the active compound containing carboxyl used in this method is organic compound, and the reactivity in aqueous solution is not enough, The sulfur dye needs to be reacted at a high temperature of at least 130°C and in an autoclave, which limits the industrial application of the dye

Images