Method for preparing dimethyldichlorosilane from high-boiling and low-boiling components of organosilicon by catalytic decomposition and disproportion

Abstract

The invention provides a method for preparing dimethyldichlorosilance by cracking and disproportionation reaction of high-boiling and low-boiling components of organic silicon. In the method, high-boiling and low-boiling components generated in the process of producing organic silicon monomer dimethyldichlorosilance (CH3)2SiCl2), are served as main raw materials which are subjected to the cracking and disproportionation reaction with an aluminum powder which is served as a catalyst in a high-pressure reactor under the condition of warming and pressurizing, and then the dimethyldichlorosilance is obtained after the resultants of the reaction are rectified and separated; the temperature in the high-pressure reactor ranges from 250 to 350 DEG C, and the stirring speed ranges from 200 to 350r / min; the reaction pressure in the high-pressure reactor is between 6 and 10MPa, and holding time ranges from 1 to 5 hours; the amount of the catalyst used in the high-pressure reactor accounts for 0.5 to 1.0 percent. In the mixture of high-boiling and low-boiling components, the mass ratio of the low-boiling components to the high-boiling components ranges from 1:0.7 to 1.1. The method has the advantages of lower production cost, and high target product yield.

Description

technical field [0001] The present invention relates to the production of organosilicon monomers (CH 3 ) 2 SiCl 2 The research field of comprehensive utilization of high boilers and low boilers produced in the process. Especially related to a method to produce monomer (CH 3 ) 2 SiCl 2 The high boilers and low boilers produced in the process are used as the main raw materials, and aluminum powder is used as a catalyst in a high-pressure reactor to prepare dimethyldichlorosilane (CH 3 ) 2 SiCl 2 Methods. technical background [0002] Methyl chlorosilane is an important monomer of organosilicon polymers. Methyl chlorosilane can produce a series of silicon-containing polymer materials such as silicone oil, silicone rubber, and silicone resin through hydrolysis, cracking, and polycondensation reactions. The main chain of the polymer-like material is composed of -Si-O- chains composed of silicon atoms and oxygen atoms alternately arranged, which resembles the structure of...

AI Technical Summary

Problems solved by technology

[0005] (1) Chinese patent 92111250.5 discloses a method for preparing methylchlorosilane by cracking methylchlorodisilane in high boilers. The reaction catalyst is noble metals such as platinum and palladium. The reaction includes Si-Si bond breaking and Si-H bond, Formation of Si-Cl bonds, the disadvantage of which is that the catalysts for this method are expensive

[0006] (2) Chinese patent 97113213.5 discloses a kind of HCl, the methyl chlorodisilane in the high boiler and CH 3 SiCl 3 The method for preparing methylchlorosilane by reaction, the catalyst of the reaction is aluminum trichloride, its disadvantage is that it needs to use HCl as the gas source, and the catalyst is difficult to regenerate and recycle

The above method uses methyl chloride as the gas source, utilizes the gas-solid heterogeneous phase reaction of stirred bed or stirred bed-fixed bed, and the yield of dimethyl dichlorosilane is about 30% lower