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Preparation method of adipic dihydrazide

A technology of adipic acid dihydrazide and adipic acid, which is applied in the field of preparation of adipic acid dihydrazide, can solve the problems of high salt content and COD content, difficulty in wastewater treatment, large waste discharge, etc. The effect of reducing emissions, eliminating esterification, and reducing purity

Inactive Publication Date: 2018-07-20
李亚杉
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the two-step method improves the yield compared with the one-step method, it needs to carry out the esterification reaction of adipic acid and methanol / ethanol earlier, which increases the reaction steps and increases the production cost. In addition, due to the esterification reaction The use of concentrated sulfuric acid as a catalyst will produce a large amount of acidic organic wastewater. After neutralization with alkali, the salt content and COD content in the wastewater are very high. The wastewater treatment is difficult and expensive. Due to the large amount of waste discharge, it is easy to cause environmental pollution. Pollution

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] 150g of adipic acid, 200g of hydrazine hydrate with a content of 80% and TiO 2 / ZrO 2 Put 15g of the composite catalyst into a four-necked flask equipped with stirring, thermometer and rectification column, start stirring, heat up to reflux, when steam enters the rectification column, extract water vapor at the column top temperature of 98°C to 100°C, and then React at reflux temperature for 4 to 6 hours. When there is no condensed water flowing out from the top of the rectification column, the reaction is ended. Use vacuum distillation to distill the remaining hydrazine hydrate in the flask for recovery. After all hydrazine hydrate is distilled, add an appropriate amount of pure water to the flask The solid matter is fully dissolved, then the solution is poured out, and the TiO is recovered by suction filtration. 2 / ZrO 2 Composite catalyst, the filtrate was transferred to a distillation bottle to evaporate under reduced pressure to remove water to obtain adipic acid...

Embodiment 2

[0015] With 150g of adipic acid, 210g of hydrazine hydrate and TiO with a content of 90% 2 / ZrO 2 Put 22g of the composite catalyst into a four-necked flask equipped with stirring, thermometer and rectification column, start stirring, heat up to reflux, when steam enters the rectification column, extract water vapor at the column top temperature of 98°C to 100°C, and then React at reflux temperature for 4 to 6 hours. When there is no condensed water flowing out from the top of the rectification column, the reaction is ended. Use vacuum distillation to distill the remaining hydrazine hydrate in the flask for recovery. After all hydrazine hydrate is distilled, add an appropriate amount of pure water to the flask The solid matter is fully dissolved, then the solution is poured out, and the TiO is recovered by suction filtration. 2 / ZrO 2 Composite catalyst, the filtrate was transferred to a distillation bottle to evaporate under reduced pressure to remove water to obtain adipic...

Embodiment 3

[0017] Adipic acid 150g, content are hydrazine hydrate 225g of 99% and TiO 2 / ZrO 2 Put 30g of composite catalyst into a four-neck flask equipped with stirring, thermometer and rectification column, start stirring, heat up to reflux, when the steam enters the rectification column, extract water vapor at the column top temperature of 98°C to 100°C, and then React at reflux temperature for 4 to 6 hours. When there is no condensed water flowing out from the top of the rectification column, the reaction is ended. Use vacuum distillation to distill the remaining hydrazine hydrate in the flask for recovery. After all hydrazine hydrate is distilled, add an appropriate amount of pure water to the flask The solid matter is fully dissolved, then the solution is poured out, and the TiO is recovered by suction filtration. 2 / ZrO 2 Composite catalyst, the filtrate was transferred to a distillation flask to evaporate under reduced pressure to remove water to obtain adipic acid dihydrazide...

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PUM

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Abstract

The invention provides a preparation method of adipic dihydrazide. The method is characterized by taking adipic acid and hydrazine hydrate as raw materials, adopting a TiO2 / ZrO2 composite catalyst andperforming hydrazide reaction at a certain temperature to prepare the adipic dihydrazide. The hydrazine hydrate is kept to be excess in the reaction system, and the water generated by reaction is continuously separated out of the reaction system, thereby effectively promoting the hydrazide reaction and improving the reaction yield. Compared with the prior art, the method provided by the inventionhas the advantages that the reaction yield is high, the after-treatment is simple, the product contains few impurities and has high purity, the catalyst can be recycled, the esterification reaction is omitted, process steps are reduced, the production cost is lowered, the emission of waste is reduced, and the method is an environment-friendly production process.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a preparation method of adipic acid dihydrazide. Background technique [0002] Adipate dihydrazide (ADH), a white crystalline solid, is easily soluble in water, has a symmetrical molecular structure, and is a bifunctional compound. ADH is a good cross-linking agent, which can be cross-linked with carbonyl groups. The typical cross-linking with hyaluronic acid is used in medicine, and the cross-linking with diacetone acrylamide is used in water-based resins. With the increasingly stringent restrictions on volatile organic substances in coatings by environmental regulations, in recent years, scholars at home and abroad have conducted a lot of research on water-based coatings, and related products have developed rapidly, and have been fully or partially replaced in many application fields. For solvent-based coatings in the traditional sense, it can be expecte...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C241/04C07C243/28B01J21/06
CPCB01J21/066B01J23/002C07C241/04C07C243/28Y02P20/584
Inventor 李亚杉
Owner 李亚杉