A kind of synthetic method of reactive black dye

Abstract

The invention discloses a synthetic method of an active black dye. The synthetic method comprises the following steps: (1) adding water and ice into para-ester and pulping to obtain para-ester slurry; (2) adding hydrochloric acid and a sodium nitrite water solution into the para-ester slurry obtained in the step (1) to perform a diazo reaction to obtain a diazonium liquid; and(3) adding an H acid and sulfonic acid type dispersant into the diazonium liquid obtained in the step (2) to perform a coupling reaction; performing after-treatment after the reaction is ended to obtain the active black dye, wherein during the initial stage of the coupling reaction, steam is charged for heating a coupling reaction liquid. According to the synthetic method, an anionic dispersant is added during coupling reaction of para-ester diazonium salt and H acid dry powder acid, and the temperature is directly increased to a most suitable temperature for acid coupling by using steam, so the synthesis time of the active black KN-B is greatly shortened, the dye yield and solid content are increased, and thus the aim of energy-saving production is realized.

Description

technical field [0001] The invention belongs to the technical field of reactive dyes, in particular to a method for synthesizing reactive black dyes. Background technique [0002] Reactive Black KN-B, namely C.I. Reactive Black 5 (C.I.20505), is a kind of bi-reactive azo dye with wide application and large production capacity. The advantage of this dye is that it is cheap, has good directness and level dyeing , wet treatment fastness is good, in line with environmental requirements. At present, the navy blue components of almost all black dyes are based on C.I. Reactive Black 5, whose content accounts for more than 70% of the three primary colors. [0003] The main synthesis process of the present reactive black dye KN-B comprises the following steps: (1) the para-ester is ice-milled with ice-water mixture for 20 hours in a glass steel reactor, and then hydrochloric acid and sodium nitrite solution are added to the para-ester for The diazotization reaction obtains the para...

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Problems solved by technology

[0012] This preparation method has a long reaction cycle and a large amount of ice used; the reaction material of para-ester diazonium salt and H acid dry powder is thick, and the mass transfer effect is poor, resulting in incomplete coupling reaction; the reaction time of para-ester diazonium salt and H acid dry powder Long and difficult to stir, very time-consuming and power-consuming; and because the para-ester diazonium salt is easy to decompose under heating conditions, it is not possible to use a separate heating method to improve the reaction efficiency

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