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Method for preparing 2-amido-8-naphthol-6-sulfonic acid

A technology of naphthol and sulfonic acid, applied in the field of chemistry, to achieve the effects of less environmental pollution, high product purity and good fluidity

Inactive Publication Date: 2008-05-21
浙江海晨化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is: to use pressure alkali fusion to overcome the deficiencies of the prior art, to improve the fluidity of the reaction material, to make the reaction more stable and complete, thereby improving product quality, reducing cost, and reducing environmental impact. pollution, making the process more reliable

Method used

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  • Method for preparing 2-amido-8-naphthol-6-sulfonic acid

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Effect test

Embodiment 1

[0024] Add the water of 900L in the concentration pot, start to stir, add the sodium hydroxide of 600 kilograms 96%. After sodium hydroxide all dissolved, add the amino G salt of 1200 kilograms in batches. Afterwards, the temperature is raised to catch the ammonia and concentrate, and the ammonia gas produced is recovered by the ammonia gas recovery system. When ammonia no longer escapes, add 1000 kilograms of 96% sodium hydroxide, then, transfer to the autoclave, and seal the autoclave. Continue to raise the temperature to 195-200°C, keep the temperature for 10 hours, and keep the pressure at 0.2-0.5Mpa. After the heat preservation is over, transfer the alkali melt to the acid analysis pot, acidify it with 30-50% sulfuric acid at 80-90°C to pH ≤ 1, and drive out SO at 90-100°C 2 1-2 hours, SO 2 into the recycling system. Finally, lower the temperature to 50-55°C for filtration, wash the filter cake with warm water, drain it, and dry it to obtain the finished product of g...

Embodiment 2

[0026] Add 4220 kilograms of 30% sodium hydroxide into the concentration pot, and add 1200 kilograms of amino G salt in batches when the temperature is raised to 70-80°C while stirring. Afterwards, the temperature is raised to catch the ammonia and concentrate, and the ammonia gas produced is recovered by the ammonia gas recovery system. When the ammonia gas no longer escapes, continue to concentrate until the sodium hydroxide content is 35-40%, then transfer to the autoclave, and seal the autoclave. Continue to raise the temperature to 195-200°C, keep the temperature for 10 hours, and keep the pressure at 0.2-0.5Mpa. After the heat preservation reaction is over, transfer the alkali melt to the acid analysis pot, acidify it with 30-50% sulfuric acid at 80-90°C to pH ≤ 1, and drive out SO at 90-100°C 2 1-2 hours, SO 2 into the recycling system. Finally, lower the temperature to 50-55°C for filtration, wash the filter cake with warm water, drain it, and dry it to obtain the ...

Embodiment 3

[0028] Add 3165 kg of 30% sodium hydroxide into the concentration pot, and add 1200 kg of amino G salt in batches when stirring and heating up to 70-80°C. Afterwards, the temperature is raised to catch the ammonia and concentrate, and the ammonia gas produced is recovered by the ammonia gas recovery system. When ammonia no longer escapes, add 492 kilograms of 90% potassium hydroxide, and continue to concentrate to a content of 35-40% (in sodium hydroxide), then, transfer to the autoclave, and seal the autoclave. Continue to raise the temperature to 195-200°C, keep the temperature for 6 hours, and keep the pressure at 0.2-0.5Mpa. After the heat preservation is over, transfer the alkali melt to the acid analysis pot, acidify it with 30-50% sulfuric acid at 80-90°C to pH ≤ 1, and drive out SO at 90-100°C 2 1-2 hours, SO 2 into the recycling system. Finally, lower the temperature to 50-55°C for filtration, wash the filter cake with warm water, drain it, and dry it to obtain th...

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Abstract

The invention relates to a method for preparing 2-amino-8-naphthol-6-sulfonic acid. The method uses 2-naphthylamine-6,8-disulfonic acid or its salt as raw material and alkali solution under stirring conditions reaction, and then transferred to a pressure reaction kettle for pressure alkali fusion in the state of no ammonia, and finally after cooling down, acidifying the alkali melt with acid to obtain the target product 2-amino-8-naphthol-6-sulfonic acid. Compared with the prior art, the process reaction system of the present invention has better fluidity, less power consumption, no coking, high product purity, less environmental pollution, and the product can be directly used in the synthesis of high-grade dyes and organic pigments without refining.

Description

technical field [0001] The invention relates to the field of chemistry, in particular to a method for preparing 2-amino-8-naphthol-6-sulfonic acid by using 2-naphthylamine-6,8-disulfonic acid or its salt as a raw material by pressure alkali fusion. Background technique [0002] The "Fine Chemical Intermediates Production Technology" published by the editorial department of "Dye Industry" introduced that there are two process routes for 2-amino-8-naphthol-6-sulfonic acid: 1: use 2-naphthol as raw material and use 20% Sulfonation with oleum yields a mixture of 2-naphthol-6,8-disulfonic acid and 2-naphthol-3,6-disulfonic acid. 2-Naphthol-6,8-disulfonic acid was isolated as potassium salt and 2-naphthol-3,6-disulfonic acid was isolated as sodium salt. The 2-naphthol-6,8-disulfonic acid separated from the potassium salt is mixed with ammonia water and sulfur dioxide in a certain proportion for ammoniation in an autoclave, and the obtained 2-naphthylamine-6,8-disulfonic acid is n...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C309/50C07C303/22
Inventor 张七男李洪林颜晓明赵强
Owner 浙江海晨化工有限公司
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