Method for preparing N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide

A technology of adipamide and hydroxyethyl, applied in the field of N, can solve the problems of unfavorable industrial production, low toxicity, complicated route, etc., and achieve the effects of increased yield, easy industrialization, and simple process

Inactive Publication Date: 2010-12-29
太仓市运通化工厂
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] N, N, N', N'-tetrakis(2-hydroxyethyl)adipamide is an excellent curing agent for weather-resistant polyester in powder coatings. Compared with TGIC curing agent widely used at home and abroad, it has low toxicity; Does not irritate the skin; fast curing speed and other characteristics, the powder coating prepared by usi...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1: Add 348 kg of dimethyl adipate into a 2000L reactor equipped with a reflux distillation condenser, open the feeding port and drop in 2 kg of solid KOH in 2 batches until the pH value is 10-14, and heat up to 90-90 100°C, slowly add 420 kg of diethanolamine dropwise at a rate of 10-15 ml / min, methanol will be generated during the reaction, and methanol will be collected with a condenser at normal pressure, and then kept at 90-100°C for 3-5 hours , turn on the vacuum, slowly increase the vacuum, so that the methanol generated in the reactor is continuously pumped out, and the reaction is pushed to the end. When the vacuum rises to 2 mm Hg, no more methanol will be evaporated at 90-100 ° C, then stop the vacuum. At this time, a colloidal white slurry appears in the reaction kettle, which is slightly cooled to 60 ° C, and the purity of the pump is 99 % more than 500 kg of refined methanol, cooled to 0 ~ 5 ℃ and stirred to precipitate a large amount of white cryst...

Embodiment 2

[0016] Embodiment 2: add the mother liquor described in embodiment 1 in the 2000L reactor that reflux distillation condenser is housed, first reduce pressure and collect methyl alcohol, add 348 kilograms of dimethyl adipate then slightly cold, drop into 1 kilogram of solid KOH Until the pH value is 10-14, heat up to 90-100°C, slowly add 420 kg of diethanolamine dropwise at a rate of 10-15 ml / min, methanol will be generated during the reaction, and the methanol will be collected at normal pressure with a condenser , after maintaining the temperature at 90-100°C for 3-5 hours, turn on the vacuum, and slowly increase the vacuum, so that the methanol generated in the reactor is continuously drawn out, and the reaction is directed to the end. When the vacuum rises to 2 mmHg, stop the vacuum after methanol no longer evaporates at 90-100 ° C. At this time, a colloidal white slurry appears in the reaction kettle. Cool it to 60 ° C and pump in 700 °C of refined methanol. kg, cooled to ...

Embodiment 3

[0017] Embodiment 3: It is basically the same as Embodiment 1, except that the molar ratio of the involved raw material dimethyl adipate:diethanolamine:methanol is 1:2.5:10.

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PUM

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Abstract

The invention discloses a method for preparing N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide. The method comprises the following steps: dimethyl adipate is used as an initial raw material to react with diethanol amine to prepare a crude product, and solid alkali serving as catalyst is added in the reacting process, so that the reaction speed is accelerated; the crude product is separated from refined methanol, and is filtered and dried to obtain the N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide product, and the filtrate can be recycled to improve the product yield and reduce the consumption. The molar ratio of the dimethyl adipate to the diethanol amine to the methanol is 1:2-2.5:5-25. The method has the advantages of simple process and easy industrialization, and can improve the product yield to over 80 percent and the purity to over 99 percent.

Description

technical field [0001] The invention relates to a preparation method of a polyester curing agent, in particular to a preparation method of N, N, N', N'-tetrakis (2-hydroxyethyl) adipamide. Background technique [0002] N, N, N', N'-tetrakis(2-hydroxyethyl)adipamide is an excellent curing agent for weather-resistant polyester in powder coatings. Compared with TGIC curing agent widely used at home and abroad, it has low toxicity; Does not irritate the skin; fast curing speed and other characteristics, the powder coating prepared by using this product has outstanding outdoor performance, and is a real green and environmentally friendly high-quality product, but the existing synthetic N, N, N', N'-four ( The route of 2-hydroxyethyl) adipamide is complicated, which is unfavorable for industrialized production, and the product yield can reach 50% at the highest. Contents of the invention [0003] Purpose of the invention: the purpose of the invention is to overcome the deficien...

Claims

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Application Information

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IPC IPC(8): C07C233/18C07C231/02
Inventor 张卫东
Owner 太仓市运通化工厂
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