Active black dye preparation method

Abstract

The present invention provides an active black dye preparation method, which comprises: S1, adding water and ice to para-ester, and beating to obtain a para-ester slurry, wherein a mass ratio of the para-ester to the water to the ice is 1:0.35-0.45:1.0-1.2; S2, adding hydrochloric acid and a sodium nitrite aqueous solution to the para-ester slurry obtained in the step S1, and carrying out a diazo reaction to obtain a diazo liquid; and S3, adding H acid dry powder and a sulfonic acid type dispersant to the diazo liquid obtained in the step S2, carrying out a coupling reaction, and post-treating after completing the reaction to obtain the active black dye, wherein steam is introduced at the initial stage of the coupling reaction so as to heat the coupling reaction liquid. According to the present invention, the anion dispersant is added during the acid coupling reaction of the para-ester diazo salt and the H acid dry powder, and the direct heating with the steam is performed to achieve the most suitable acid coupling temperature, such that the active black KN-B synthesis time is substantially shortened, and the dye yield and the solid content are improved so as to achieve the energy-saving production purpose.

Description

technical field [0001] The invention relates to the technical field of reactive dyes, in particular to a preparation method of 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-e...

AI Technical Summary

Problems solved by technology

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