Refining method of N, N'-bis(2, 2, 6, 6-tetramethyl-4-piperidyl)-1, 6-hexamethylenediamine

A refining method, tetramethyl technology, applied in the direction of organic chemistry, etc., can solve the problems of complex production process and poor thermal stability of products

Active Publication Date: 2021-04-13
HENGSHUI KAIYA CHEM +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The main purpose of the present invention is to provide a kind of refining method of N,N'-di(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexamethylenediamine, to solve existing In the technology, when purif...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Under normal temperature and pressure, add 290g of 2,2,6,6-tetramethyl-4-piperidone, 100g of 1,6-hexamethylenediamine, and 300g of cyclohexane into the reactor, raise the temperature to 60°C, and keep the pressure At 5 ~ 8KPa, react for 20 hours, negative pressure reflux to remove the water brought in and generated by the reaction. After the reaction was completed, the solvent in the reaction was removed by vacuum distillation to obtain a Schiff base.

[0039] Put 370g of Schiff's base directly into the autoclave, add 30g of skeleton nickel as a catalyst, replace the air in the autoclave with inert gas nitrogen or argon, and then replace it with hydrogen, heat up to 70-80°C, pressure 6-7MPa, and react for 10 Hour hydrogen pressure no longer drops.

[0040] After the reaction is completed, the temperature is lowered and the pressure is released, and the catalyst is separated by suction filtration under reduced pressure to obtain a hydrogenation feed liquid. Distillatio...

Embodiment 2

[0042] Under normal temperature and pressure, add 440g of 2,2,6,6-tetramethyl-4-piperidone, 150g of 1,6-hexanediamine, and 700g of n-hexane into the reactor, raise the temperature to 50°C, and keep the pressure at 50KPa, react for 12 hours, negative pressure reflux to remove the water brought in and generated by the reaction. After the reaction was completed, the solvent in the reaction was removed by vacuum distillation to obtain a Schiff base.

[0043] Put 500g of Schiff's base directly into the autoclave, add 0.1g of Pd-C as a catalyst, replace the air in the autoclave with inert gas, and then replace it with hydrogen, raise the temperature to 70-80°C, pressure 3.5-4.5MPa, and react for 4 hours The hydrogen pressure no longer drops.

[0044] After the reaction is completed, the temperature is lowered and the pressure is released, and the catalyst is separated by suction filtration under reduced pressure to obtain a hydrogenation feed liquid. Rectification of hydrogenation...

Embodiment 3

[0046] Under normal temperature and pressure, add 290g of 2,2,6,6-tetramethyl-4-piperidone, 100g of 1,6-hexamethylenediamine, and 300g of cyclohexane into the reactor, raise the temperature to 60°C, and keep the pressure At 5-8KPa, react for 20 hours, dehydrate under negative pressure reflux. After the reaction was completed, the solvent in the reaction was removed by vacuum distillation to obtain a Schiff base.

[0047] Put 370g of Schiff's base directly into the autoclave, add 30g of skeleton nickel as a catalyst, replace the air in the autoclave with inert gas, and then replace it with hydrogen, raise the temperature to 70-80°C, press 6-7MPa, and react for 10 hours without hydrogen pressure. Go down again.

[0048] After the reaction is completed, the temperature is lowered and the pressure is released, and the catalyst is separated by suction filtration under reduced pressure to obtain a hydrogenation feed liquid. Rectification of hydrogenation feed liquid: control the p...

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PUM

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Abstract

The invention provides a refining method of N,N'-bis(2, 2, 6, 6-tetramethyl-4-piperidyl)-1, 6-hexamethylenediamine. The method comprises the following steps: taking 2, 2, 6, 6-tetramethyl-4-piperidone and 1,6-hexamethylenediamine as raw materials to react to prepare an N,N'-bis(2, 2, 6, 6-tetramethyl-4-piperidyl)-1, 6-hexamethylenediamine reaction solution; rectifying the reaction solution, and evaporating out light components and a crude product; and recrystallizing the crude product in a second solvent to obtain a target product. According to the invention, the purification process is effectively simplified, the problem of complex process caused by repeated concentration and crystallization of the crystallization mother liquor is avoided, and the product has more stable performance, can be stored for a long time and is not easy to discolor.

Description

technical field [0001] The present invention relates to the technical field of organic synthesis, in particular to the purification of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine method. Background technique [0002] Hindered amine light stabilizers have a good effect on inhibiting photooxidation and photodegradation of polymers, and their functional efficiency is usually several times higher than that of traditional absorbing light stabilizers. They have low toxicity and excellent synergistic effects, so they are widely used. Due to its relatively low molecular weight, the early HALS products have the disadvantages of being not resistant to extraction and easy to migrate during application. Based on this, high molecular weight has become one of the development trends of HALS. The hindered amine light stabilizers 944 and 3346 widely used in the market are all high molecular weight products. [0003] N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanedi...

Claims

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Application Information

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IPC IPC(8): C07D211/58
CPCC07D211/58
Inventor 刘荣新代广星王慧君贾辰游文云孙春光李海平
Owner HENGSHUI KAIYA CHEM
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