Production method of dodecalactam

A technology of laurolactam and cyclododecanone is applied in the production field of high-purity laurolactam to achieve the effects of less by-products, not easy to agglomerate, and high product purity

Active Publication Date: 2019-06-11
WANHUA CHEM GRP CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] The purpose of the present invention is to provide a method for producing high-purity laurolactam, which solves the problem of oximation reaction rate, the problem of heavy discharge heat and the purification of laurolactam products

Method used

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  • Production method of dodecalactam
  • Production method of dodecalactam
  • Production method of dodecalactam

Examples

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Effect test

Embodiment 1

[0043] Step 1: 180 g of hydroxylamine sulfate (12.5 wt%) aqueous solution was added with ammonia to neutralize to pH 6-7 to obtain a hydroxylamine solution. In the round-bottomed bottle, 100 g of cyclododecanone was heated and melted, kept at 90° C., and the aforementioned hydroxylamine solution was added dropwise to the round-bottomed bottle with stirring. The dropwise addition time was about 10min. After the dropwise addition, the reaction was continued for 1h, and then 100 g of 1-cyclohexyl-n-tridecane was added to separate the solution. The oil phase obtained after liquid separation contained 0.2% water and 100 ppm of inorganic salts.

[0044] Step 2: The aforementioned oil phase is subjected to vacuum rectification, and the conditions for the distillation of cyclododecanone are the pressure of 1kPa, the temperature of 110°C, and the theoretical plate number of the rectification column is not less than 20. About 45 g of cyclododecanone was obtained with a purity of 98.7 w...

Embodiment 2

[0067] Step 1: 100 g of hydroxylamine sulfate (12.5 wt%) aqueous solution was added with ammonia to neutralize to pH 6-7 to obtain a hydroxylamine solution. In the round-bottomed bottle, 100 g of cyclododecanone was heated and melted, kept at 90° C., and the aforementioned hydroxylamine solution was added dropwise to the round-bottomed bottle with stirring. The dropwise addition time was about 10min. After the dropwise addition was completed, the reaction was continued for 1h, and then 120 g of 4-isopropyl-n-decylcyclohexane was added to separate the liquids. The oil phase obtained after liquid separation contained 0.15% water and 80 ppm of inorganic salts.

[0068] Step 2: The aforementioned oil phase is subjected to vacuum rectification, and the conditions for the distillation of cyclododecanone are the pressure of 1kPa, the temperature of 110°C, and the theoretical plate number of the rectification column is not less than 20. About 65 g of cyclododecanone was obtained, wit...

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Abstract

The invention relates to a production method of dodecalactam with high purity. The method comprises the following steps: carrying out a reaction of cyclododecanone and hydroxylamine, and adding a solvent a to assist the liquid separation; and recovering the remaining cyclododecanone from the oil phase obtained from the liquid separation by vacuum rectification, mixing the solution rich in cyclododecanoxime with concentrated sulfuric acid, carrying out a Beckmann rearrangement reaction, neutralizing the mixed solution with ammonia water after the reaction is finished, performing the liquid separation to obtain dodecalactam a solution, adsorbing impurities by alumina and then adding a solvent b, and cooling and crystallizing the solution in the mixed solvents of a and b to obtain the dodecalactam solid product. The dodecalactam product obtained by the method has high purity and light color, and is suitable for producing high-grade resin materials.

Description

technical field [0001] The present invention relates to a kind of production method of laurolactam, in particular to a kind of production method of high-purity laurolactam. Background technique [0002] Laurolactam is an important chemical raw material for the production of high-performance nylon material - nylon 12. [0003] In industry, laurolactam is obtained from cyclododecanone through oximation and Beckmann rearrangement. Although in terms of chemical reaction form, the preparation of laurolactam from cyclododecanone is similar to the preparation of caprolactam from cyclohexanone. However, because the physicochemical properties of cyclododecanone and its corresponding derivatives are significantly different from those of cyclohexanone and its corresponding derivatives, the difficulty in producing laurolactam is significantly increased, and there are still many problems in the existing technology. [0004] First, the oximation reaction process is complicated and the r...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D201/06C07D225/02
Inventor 张彦雨陈海波杜旺明边新建赵晶黎源孟熙王文
Owner WANHUA CHEM GRP CO LTD
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