A continuous production process of azo disperse dyes with ester groups

Abstract

The invention discloses a continuous production process of an azo disperse dye with an ester group. Through the combination of an ultrasonic mixer, a supergravity machine enhanced reaction and a supergravity machine enhanced crystal transformation, the beating process of traditional process materials is reduced, and the post-treatment kettle is reduced. In the crystal conversion process, the entire process from the early stage of the reaction to the post-processing of the finished product is continuous. Through the strengthening of the equipment, the reaction efficiency is improved and the reaction residence time is greatly shortened. Therefore, the volume of the equipment is greatly reduced, and the material in the kettle equipment The transfer process in the process reduces the amount of kettle equipment, greatly reduces the cost of production equipment and site use, reduces the volume of equipment in each link, increases the safety and controllability of the reaction, and has obvious advantages in product purity and yield.

Description

technical field [0001] The invention relates to the technical field of preparation of disperse dyes, in particular to a continuous production process of azo disperse dyes with ester groups. Background technique [0002] Disperse dyes can be divided into three types according to molecular structure: azo type, anthraquinone type and heterocyclic type. Application performance, simple production process and low cost. Therefore, azo dyes occupy an extremely important position in disperse dyes. Among the industrially produced disperse dyes, the dyes with azo structure account for 50% and the output accounts for more than 70%. [0003] Azo disperse dyes with ester groups have the characteristics of high wet fastness and alkali washability, high cost performance, and occupy an important position in the dye industry. However, coupling compounds and dye compounds containing ester groups are prone to hydrolysis under high temperature and acidic conditions. For this reason, a large a...

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Problems solved by technology

However, coupling compounds and dye compounds containing ester groups are prone to hydrolysis under high temperature and acidic conditions

For this reason, a large amount of ice or frozen brine is usually used to carry out at a low temperature of 0-5°C, and the coupling reaction time is as long as more than 6 hours, resulting in low production efficiency, and there are still low yields due to ester hydrolysis and impurities in wastewater. The problem of high dye content and difficult treatment; although the coupling reaction time can be shortened by increasing the coupling reaction temperature, it will cause more serious hydrolysis of the ester group in the coupling component or dye molecule

[0004] Patent CN105440727A introduces the adjustment of material pH in the post-treatment process, which reduces the hydrolysis of dye compounding in the process of heating up and crystallization; but the method of adjusting material pH through post-treatment will increase the difficulty of recycling dye washing water and mother liquor water, and lead to waste water. Increased, increased wastewater treatment costs

[0005] Patent CN108047751A adopts diluting the diazo component and the coupling component separately to obtain different premixed components, and then carries out continuous feeding to suppress the hydrolysis of the dye molecules and the coupling component, but the hydrolysis in the premixing process is still unavoidable, dilute the diazo group The time-sharing diazonium salt may decompose, which will affect the product quality and yield, and there are certain safety hazards. At the same time, no clear instructions have been made for the mixer and reactor, and no better improvement has been made for the post-processing part.

[0006] Patent CN110373038A has introduced a kind of serial production method that adopts microchannel to dilute diazo, and dilute diazo and coupling components are continuously transported into the microchannel for coupling reaction. This method can reduce the amount of diazo in the coupling and feeding process due to the continuous dilution and continuous coupling. The material is hydrolyzed, but the post-treatment has not been optimized, and because the product is in a solid-liquid state, it is prone to clogging when using micro-channels. In order to avoid too frequent clogging, the pores of the micro-channels can only be increased, which inevitably reduces the mixing efficiency and thus lead to an increase in reaction time, and an increase in reaction time can also lead to hydrolysis of the material

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