Preparation method for continuously synthesizing indigo

A chemical synthesis, indigo technology, applied in the direction of organic chemistry, bis-indo-indigo blue indigo dyes, etc., can solve the problems of secondary pollution, high price, large consumption, etc., achieve complete reaction, fast reaction speed, and improve conversion. rate effect

Inactive Publication Date: 2009-12-02
JIANGSU TAIFENG CHEM
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  • Summary
  • Abstract
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  • Application Information

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Problems solved by technology

These alkalis can also be partially recovered, but require large consumption and high price of potassium hydroxide...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] The liquid anilinoacetonitrile and the liquid alkali are continuously added to the hydrolysis tower in the ratio of 1:1-1.2, and the anilinoacetate solution is obtained through a cyclic reaction, and the dry product of the anilinoacetate is obtained by drying; and then the liquid metal Sodium is continuously added to the sodium ammonia pre-synthesis tower, and at a temperature of 300-400 °C, ammonia gas is continuously introduced into the sodium ammonia synthesis tower for countercurrent reaction to generate sodium amide, and the unreacted ammonia gas is passed into the sodium ammonia pre-synthesis tower. In the tower; it is continuously added to the alkali according to a certain proportion, and then continuously or intermittently added to the mixing reactor, at a temperature of 180°C to 250°C and a pressure of 0.1-0.5Mpa, with alkali as solvent and sodium amide as solvent. Condensing agent, add the dry product of anilinoacetate continuously, react for 0.1-5h, cyclize th...

Embodiment 2

[0015] Using 9000kg of anilino acetate, 4000kg of potassium hydroxide and sodium hydroxide mixed alkali, and 2500kg of metallic sodium, the reaction was carried out for 3 hours to obtain 5110kg of indigo with a yield of 78%. The rest of the process is the same as in Example 1.

Embodiment 3

[0017] Using 9000kg of anilino acetate, 4000kg of potassium hydroxide and sodium hydroxide mixed alkali, and 2500kg of metallic sodium, the reaction was carried out for 5 hours to obtain 5250kg of indigo, and the yield was 80%. The rest of the process is the same as in Example 1.

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PUM

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Abstract

The invention discloses a preparation method for continuously synthesizing indigo, which comprises the following steps: at certain temperature, introducing nitrogen gas to liquid metallic sodium; reacting the nitrogen gas with the liquid metallic sodium in an ammonia-sodium synthesizing tower to generate sodium amide; adding the sodium amide into alkali according to certain mixture ratio; continuously or intermittently adding the mixture into a blending reactor; at certain temperature and pressure, taking the alkali as solvent and the sodium amide as a condensation agent; continuously adding anilino group acetate; cyclically synthesizing the anilino group acetate into oxyindole phenate; continuously discharging and diluting the oxyindole phenate by water; and continuously oxidizing the diluted oxyindole phenate by an oxidation reaction device to obtain indigo blue. The preparation method improves the reaction yield and the quality of products, shortens the reaction period, reduces the generation of contaminants, reduces the equipment investment and the labor intensity of workers, improves the working environment and greatly reduces the energy consumption and material consumption.

Description

technical field [0001] The invention relates to a preparation method for continuous synthesis of indigo Background technique [0002] The traditional production of indigo all adopts the kettle type reaction and batch operation. However, intermittent production has the problems of long reaction period, low production capacity per unit time, high equipment investment, large floor space, high labor intensity, many waste discharge points, large pollutant discharge, high material consumption and energy consumption. [0003] The traditional production method is to use the mixed alkali composed of potassium hydroxide and sodium hydroxide as the solvent for the indigo synthesis reaction, although the sodium amide and phenylaminoacetate in the reaction can be well dissolved in the solvent composed of this mixed alkali. , after the reaction, the product indigo can be separated from the alkali aqueous solution. These alkalis can also be partially recovered, but the potassium hydroxid...

Claims

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Application Information

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IPC IPC(8): C07D209/36C09B7/02
Inventor 张正西刘国平吴德生赵忠民栾敏红
Owner JIANGSU TAIFENG CHEM
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