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Clean production process of m-carbamidoaniline hydrochloride

A technology of ureidoaniline and clean production, which is applied in the field of clean production process of high-purity m-ureidoaniline hydrochloride, which can solve the problems of low solid content of hydrochloride, unstable dye quality, and large content detection deviation. Achieve the effects of increasing solid content, preventing the formation of diurea, and increasing yield

Active Publication Date: 2014-01-29
ZHEJIANG RUNTU INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Since the m-ureidoaniline hydrochloride produced by the reaction is dissolved in a large amount in the reaction system, it will continue to react with hydrochloric acid and sodium cyanate to form diurea. Therefore, the purity of the commercially available m-ureidoaniline hydrochloride can only reach 96%, and because a certain amount of m-phenylenediamine has not yet reacted in the reaction system, the ureidoaniline hydrochloride solution residue in the mother liquor, etc., the general yield is only about 88%. At the same time, every ton of m-ureidoaniline hydrochloride produced About 7 tons of high-salt and high-COD wastewater are produced. In addition, the m-ureidoaniline hydrochloride synthesized by traditional methods has a low solid content, which is only 60% to 70%. When it is used to synthesize dyes, the content detection deviation is large, which is easy to cause Inaccurate feeding, resulting in unstable dye quality

Method used

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  • Clean production process of m-carbamidoaniline hydrochloride
  • Clean production process of m-carbamidoaniline hydrochloride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Put 1600L of pure water in the reaction pot and start stirring. Drop into industrial sodium chloride 300kg in reaction pot. Close the equipment, open the vacuum to inhale 220kg of m-phenylenediamine, add 1.1kg of sodium nitrate, add 30% hydrochloric acid to adjust the pH value to below 0.8, after the material is completely dissolved, after cooling down to 0°C, open the automatic feeding device and start adding sodium cyanate Powder, at the same time open the hydrochloric acid automatic dripping system to add hydrochloric acid dropwise. The online system controls pH=0.8-1.0, adding 50% of the total amount of sodium cyanate within 2 hours through the automatic feeding device, and controlling the pH=1.0-1.3, adding 23% of the total amount of sodium cyanate within 1 hour , control the pH=1.1-1.4, add 25% of the total amount of sodium cyanate within 2 hours, control the pH=1.2-1.5, add 2% of the total amount of sodium cyanate within 1 hour, after adding , after half an hou...

Embodiment 2

[0034] Collect the filtrate of Example 1 and lower the temperature to 5°C to precipitate diurea. After filtering to remove impurities, collect 2800 kg of brine, take 1500 kg of it, add 400 kg of water to adjust the concentration of brine, and put it into the reaction pot. Seal the equipment and open the vacuum to inhale m-phenylenediamine. 220kg, add 6 kilograms of sodium nitrate, add sodium cyanate and hydrochloric acid by the method for embodiment 1, this process consumes hydrochloric acid 573kg, sodium cyanate 139kg.

[0035] After the reaction, heat up to 100°C to dissolve and then cool down to 20°C for recrystallization. After the filter cake was pressed dry, the filter cake was 374kg, the HPLC purity of the filter cake was 98.64%, the solid content of the filter cake was 80.0%, and the yield was 97.36%.

Embodiment 3

[0037] After the filtrate of Example 2 is collected, the temperature is lowered to 0°C to precipitate diurea, and after filtering to remove impurities, 2800 kg of brine is collected, 1400 kg of which is added to 500 kg of water to adjust the concentration of brine, and then put into a closed device in a reaction pot, and 220 kg of m-phenylenediamine is inhaled by vacuum. , suck 3 kilograms of nitric acid, add sodium cyanate and hydrochloric acid by the method for embodiment 1, this process consumes hydrochloric acid 569kg, sodium cyanate 140kg.

[0038] After the reaction, heat up to 100°C to dissolve and then cool down to 40°C for recrystallization. After the filter cake was pressed dry, the filter cake was 378kg, the HPLC purity of the filter cake was 98.63%, the solid content of the filter cake was 77.9%, and the yield was 95.78%.

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Abstract

The invention discloses a clean production process of m-carbamidoaniline hydrochloride. The clean production process comprises the following steps of: dissolving m-phenylenediamine into a sodium chloride salt water reaction system; adding an auxiliary agent into the reaction system; controlling a reaction temperature at -5 DEG C to 25 DEG C; then adding sodium cyanate and hydrochloric acid for reaction; and after the reaction is completed, carrying out post-treatment on a resulting substance to obtain m-carbamidoaniline hydrochloride, wherein the auxiliary agent is nitric acid or nitrate. According to the clean production process, salt water, instead of pure water, is used as base water, m-carbamidoaniline hydrochloride produced in the reaction can be separated out in time by using salt precipitation effects of sodium chloride, a byproduct diurea is not generated, the purity of the obtained m-carbamidoaniline hydrochloride is more than 98%, the yield is more than 95%, the content is 75%-80%, the sewage quantity is reduced by 50%, and the process is simple and high in automation degree.

Description

technical field [0001] The invention relates to a production method of a dye intermediate, in particular to a clean production process of high-purity m-ureidoaniline hydrochloride. Background technique [0002] M-ureidoaniline hydrochloride, with the structure shown in formula (I), is an important dye intermediate, mainly used in the production of fine chemicals such as reactive and acid dyes, and the reactive dye 4RFN golden yellow produced from it It is the largest monochromatic dye among reactive dye yellow varieties. [0003] [0004] At present, the most commonly used synthetic method of m-ureidoaniline hydrochloride is: take m-phenylenediamine as raw material, react with hydrochloric acid and sodium cyanate in aqueous phase, and its reaction equation is as follows: [0005] [0006] Since the m-ureidoaniline hydrochloride produced by the reaction is dissolved in a large amount in the reaction system, it will continue to react with hydrochloric acid and sodium cy...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C275/40C07C273/18
Inventor 高立江赵国生阮海兴
Owner ZHEJIANG RUNTU INST
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