Method for producing hexamethyldisiloxane by utilization of organosilicon azeotrope

A technology of hexamethyldisiloxane and trimethylchlorosilane is applied in the field of production of hexamethyldisiloxane, which can solve the problems of high requirements on equipment and equipment, being unsuitable for popularization and application, adding post-processing steps and the like, and achieving Low price, high continuous production efficiency, stable process effect

Active Publication Date: 2013-09-25
HOSHINE SILICON IND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since this method requires high boiling point solvents such as xylene, a series of post-treatment steps are added, and the process is cumbersome.
Utilization of HF or ZnF is disclosed in US2449815 2 The separation method of converting into fluorosilane, which requires relatively high equipment and equipment, is not suitable for popularization and application

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] (1) By-product azeotrope [(CH 3 ) 3 SiCl: 49.57wt%, SiCl 4 : 42.78wt%, CH 3 SiHCl 2 : 4.64wt%, HSiCl 3 : 1.31wt%, (CH 3 ) 2 SiHCl: 1.67wt%] was added to a still-type device with a packed tower for heating and distillation. The temperature of the tower was controlled at 70-80°C, and the temperature at the top of the tower was 38-42°C. Methylhydrodichlorosilane and trichlorosilane were separated. Hydrogen silicon and dimethyl hydrochlorosilane and other light components with a boiling point lower than 40°C, an intermediate mixture of silicon tetrachloride and trimethylchlorosilane is obtained in the kettle.

[0047] (2) Put the intermediate mixture obtained in step (1) into the reaction kettle for esterification, and drop ethanol into the reaction kettle by intermittent dropwise to carry out esterification reaction; at 25°C, first add 1 / 3 of the ethanol with 200L / h was dropped into the intermediate mixture, and after the dropwise addition was completed, reflux at 4...

Embodiment 2

[0054] (1) By-product azeotrope [(CH 3 ) 3 SiCl: 49.57wt%, SiCl 4 : 42.78wt%, CH 3 SiHCl 2 : 4.64wt%, HSiCl 3 : 1.31wt%, (CH 3 ) 2 SiHCl: 1.67wt%] was added to a still-type device with a packed tower for heating and distillation. Control the temperature of the tower kettle at 70-80°C, and the temperature at the top of the tower at about 40°C, and separate the light components such as methylhydrogendichlorosilane, trichlorosilane and dimethylhydrogenchlorosilane with a boiling point lower than 40°C. An intermediate mixture of silicon tetrachloride and trimethylchlorosilane was obtained.

[0055] (2) Put the intermediate mixture obtained in step (1) into the reaction kettle for esterification, and drop ethanol into the reaction kettle by intermittent dropwise to carry out esterification reaction; at 30°C, first add 1 / 2 of the ethanol with 250L / h was dropped into the intermediate mixture, and after the dropwise addition was completed, reflux at 45°C for 2 hours, and then ...

Embodiment 3

[0062] (1) By-product azeotrope [(CH 3 ) 3 SiCl: 48.36wt%, SiCl 4 : 43.63wt%, CH 3 SiHCl 2 : 4.97wt%, HSiCl 3 : 1.26wt%, (CH 3 ) 2 SiHCl: 1.63wt%] was added to a still-type device with a packed tower for heating and distillation. Control the temperature of the tower kettle at 70-80°C, and the temperature at the top of the tower at about 40°C, and separate the light components such as methylhydrogendichlorosilane, trichlorosilane and dimethylhydrogenchlorosilane with a boiling point lower than 40°C. An intermediate mixture of silicon tetrachloride and trimethylchlorosilane was obtained.

[0063](2) Put the intermediate mixture obtained in step (1) into an esterification reaction kettle, and drop ethanol into the reaction kettle by intermittent dropwise to carry out esterification reaction; at 25°C, first add 1 / 2 of the ethanol with 250L / h was dropped into the intermediate mixture, and after the dropwise addition was completed, reflux at 40°C for 2 hours, and then at 40°...

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Abstract

The invention discloses a method for producing hexamethyldisiloxane by the utilization of organosilicon azeotrope, comprising the following steps: (1) carrying out heating distillation on the organosilicon azeotrope, and removing fractions with boiling point being lower than 40 DEG C to obtain an intermediate mixture; (2) mixing the intermediate mixture and ethanol to carry out an intermittence esterification reaction, carrying out heating distillation on the reaction solution, and collecting fractions with the boiling point being lower than 80 DEG C to obtain a trimethylchlorosilane crude product; and (3) hydrolyzing the trimethylchlorosilane crude product, and separating from the hydrolysate so as to obtain hexamethyldisiloxane. According to the method provided by the invention, price of the raw materials is cheap, supply is sufficient, condition during the reaction process is mild, the technology is stable, continuous production efficiency is high, there is no by-product, and it is not necessary to use other poisonous and harmful organic solvents. Purity of the obtained hexamethyldisiloxane finished product is more than 99%, and the content of chloride ions is less than 100ppm.

Description

technical field [0001] The invention relates to the technical field of recycling by-products in the synthesis and production of organosilicon monomers in the chemical industry, in particular to a method for producing hexamethyldisiloxane by using organosilicon azeotropes. Background technique [0002] Organosilicon materials are mainly a kind of polymer compound with Si-O bond as the main chain, and then introduce organic groups as side chains on Si. It has excellent performance and unique functions, and is widely used in military industry, aerospace, medical treatment, chemical industry, etc. field, where (CH 3 ) 2 SiCl 2 It is the most important organosilicon monomer. Since American Luo Qiao (US2380995) invented the method of directly synthesizing organochlorosilane by using methyl chloride and silicon powder under the catalysis of copper powder in 1941, the synthesis technology of methyl chlorosilane has been developed for more than half a century and has been perfecte...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07F7/08
Inventor 彭金鑫方红承曹华俊孙卫红兰永平谭军欧阳玉霞
Owner HOSHINE SILICON IND CO LTD
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