Method of synthesizing sulfonation paratope ester

Abstract

The invention belongs to the technology field of the reactive dye, in particular to the synthetic method of the sulfonation para-ester. The synthetic method of the sulfonation para-ester comprises sulfonation, hydrolysis, dilution, purification, neutralizing salting-out and filtration and over dry. The difference with the prior art is that the control temperature is always not more than 5 DEG C. in the unit operations of dilution, filtration and neutralizing salting-out; the diatomite with volume of 0.6 to 0.7 per cent of the total volume of the reaction solution is added after dilution, and perform filter processing after stirring evenly; the filter cake is adjusted to pulping by water and the pH value is adjusted equal to 6.0 to 6.5 by 20 per cent to 30 per cent sodium bicarbonate solution; the potassium chloride is added based on 7 per cent to 8 per cent of the total volume of the reaction solution to do salting-out; the filter cake is kept after filtration and is dried under the temperature of 80 DEG C. to 85 DEG C.. The adoption of the synthetic method of the sulfonation para-ester of the invention basically avoids the hydrolysis of the ester, filters the impurities such as the byproduct, improves the product quality and realizes the dryness of the product.

Description

technical field [0001] The invention belongs to the technical field of reactive dyes, in particular to a synthesis method of sulfonated para-ester. Background technique [0002] Sulfonated para-ester is an important intermediate in the production of reactive dyes, mainly used in the synthesis of reactive red 330#, red 333#, orange 320# and other S-type reactive dyes. Because the structural dye has the characteristics of bright color, good fastness, high absorption and high solubility, the series of dyes synthesized with this intermediate are well received by users. Major manufacturers at home and abroad have developed S-type dyes containing sulfonated para-esters. [0003] The synthesis reaction process of sulfonated para-ester is complicated, and the product standards of existing manufacturers are not high. [0004] As shown in Figure 2, the existing production process: [0005] 1) Sulfonation [0006] Put oleum into the sulfonation tank, and slowly put the para-ester e...

AI Technical Summary

Problems solved by technology

[0018] The polysulfonate and ester group hydrolyzate generated in the sulfonation reaction, as well as the unreacted para-ester cannot be separated from the sulfonation reactant, which makes the isomers in the sulfonate very high and affects the quality of the product

[0019] If the production product is dried at 80-85°C, due to the large amount of free acid contained, the ester group is almost 100% hydrolyzed under the catalysis of the acid, so it cannot be dried and can only be used as a trendy product

Trendy products are not easy to transport and cannot be stored for a long time

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