Method for preparing azo dye with alkalescent arylamine serving as diazotization ingredient

An azo dye, weak alkaline technology, applied in azo dyes, monoazo dyes, organic dyes, etc., can solve the problems of water or soil acidification, low utilization rate of sulfuric acid, ecological environment hazards, etc. The effect of avoiding pollution reprocessing and saving production costs

Active Publication Date: 2013-08-28
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] In the production process of azo dyes with weakly basic aromatic amines as diazo components, the utilization rate of sulfuric acid is very low. After the industrial reaction, the waste liquid containing a large amount of concentrated sulfuric acid is usually treated with lime and discharged, which is difficult to recycle.
If these waste liquids are discharged directly into the environment without treatment, it will not only acidify the water body or soil, cause harm to the ecological environment, but also waste a lot of resources

Method used

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  • Method for preparing azo dye with alkalescent arylamine serving as diazotization ingredient
  • Method for preparing azo dye with alkalescent arylamine serving as diazotization ingredient
  • Method for preparing azo dye with alkalescent arylamine serving as diazotization ingredient

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] 1st reaction

[0027] (1) Preparation of weakly basic arylamine diazonium salt solid: Add 40ml of ethyl acetate and 0.82g of 2-cyano-4-nitroaniline (diazo component) into a 100ml three-necked flask connected with electric stirring, Stir to dissolve, ice bath (0-5 ℃) 10min. Add 2.75g of 40% fluoboric acid and 5.0g of 98% concentrated sulfuric acid dropwise, and continue stirring for 10 minutes. Then 0.35 g of sodium nitrite was added, and the reaction was stirred vigorously for 1.5 h. Thin-layer chromatography detected that the reaction of the raw materials had been completed. Suction filtration at low temperature (0-5°C) to obtain a white crystalline solid, and the pale yellow filtrate is recycled in an ice bath (0-5°C).

[0028] (2) Coupling reaction: Add 1.03g of 3-(N,N-diethyl)aminoacetanilide (coupling component) into a 500ml beaker filled with 10ml of water, add a small amount of acid and stir to dissolve, ice bath (0 -5°C) 10min. Under vigorous stirring, crush...

Embodiment 2

[0046] The first reaction: except that the diazo component is 0.92g 2,4-dinitroaniline, and the addition amount of 40% fluoroboric acid is 1.65g, other additions and operations are the same as the first reaction in Example 1. This reaction obtained 1.51 g of solid dye, and the yield was 75.5%.

[0047] The 1st to 6th cycle reactions: the solid preparation process of weakly basic arylamine diazonium salts uses the filtrate of the previous cycle reaction, no need to add ethyl acetate, only 0.50g98% concentrated sulfuric acid is added, and the remaining diazo components , fluoboric acid and sodium nitrite addition and reaction operation are the same as the first reaction, and the coupling reaction is also the same as the first reaction. The amount of dyes obtained in the 1st to 6th cycle reactions were 1.71g, 1.77g, 1.76g, 1.82g, 1.64g and 1.69g respectively, and the yields were 85.5%, 88.5%, 88.0%, 91.0%, 82.0% respectively and 84.5%.

[0048] After 6 cycles of reaction, the d...

Embodiment 3

[0055] The first reaction: except that the diazo component is 1.21g 2-cyano-4-nitro-6-bromoaniline, and the addition of ethyl acetate is 60ml, other additions and operations are the same as the first reaction in Example 1 same. This reaction yielded 1.88 g of solid dye, with a yield of 82.1%.

[0056] The 1st to 4th cycle reactions: the solid preparation process of weakly basic arylamine diazonium salts uses the filtrate of the previous cycle reaction, no need to add ethyl acetate, only 0.50g of 98% concentrated sulfuric acid and 40% fluoboric acid are added The amount is 2.20g, and the addition amount and reaction operation of the remaining diazo components and sodium nitrite are the same as the first reaction, and the coupling reaction is also the same as the first reaction. The amount of dyes obtained from the first to the fourth cycle reactions were 2.03g, 1.99g, 1.92g and 1.88g, respectively, and the yields were 88.6%, 86.5%, 83.5% and 82.0%, respectively.

[0057] Afte...

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Abstract

The invention provides a method for preparing an azo dye with alkalescent arylamine serving as a diazotization ingredient. The method is characterized in that in a diazotization reaction, ethyl acetate, propyl acetate, butyl acetate, acetone, glycol dimethyl ether or polyethylene glycol 200 is used as a diazotization reaction solvent instead of concentrated sulfuric acid, fluoroboric acid or naphthalene disulfonic acid is used as a diazo salt stabilizer instead of concentrated sulfuric acid, a diazo salt is filtered and separated, filtrate is directly applied to a next diazotization reaction of the alkalescent arylamine, and the diazo salt is applied to a coupling reaction so as to synthesize disperse dyes. Compared with the traditional preparation methods, the method has the advantages that the dosage of the concentrated sulfuric acid can be reduced greatly during the diazotization reaction of the alkalescent arylamine, so that the production cost of the azo dye with the alkalescent arylamine serving as the diazotization ingredient is reduced greatly, the environmental pollution can be reduced from the source, the pollution retreatment of a production end is avoided, and thus, the method has broad application prospects.

Description

technical field [0001] The invention relates to a method for preparing an azo dye with a weakly basic aromatic amine as a diazo component. Background technique [0002] There are many kinds of azo dyes, including acid, direct, reactive, and disperse dyes. They are the dyes with the most varieties and the largest output among all synthetic dyes, and their annual output accounts for more than half of the world's dyes. Azo dyes with weakly basic aromatic amines as diazo components are mainly used as disperse dyes, and disperse dyes have gradually developed into one of the largest synthetic dyes. [0003] The production process of azo dyes involves a diazotization reaction process, that is, the reaction of arylamine (diazo component) and nitrous acid (diazonium agent) to form diazonium salt, which is an important step in the production of azo dyes. Because nitrous acid is unstable, sodium nitrite and hydrochloric acid or sulfuric acid are usually used to react the nitrous acid ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09B29/08
Inventor 唐炳涛张淑芬马威
Owner DALIAN UNIV OF TECH
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