Method for preparing methyl chlorosilane by cracking organic silicon high boiling point substance

Abstract

The invention discloses a method for preparing methyl chlorosilane by cracking organic silicon high boiling point substance, which takes the organic silicon high boiling point substance produced by organic silicon mixed monomer as raw material, and comprises the steps of: when the organic silicon high boiling point substance is forged to 2 / 3 of the liquid level in a cracking kettle by a pump, adding catalyst triethylamine and tributylamine; filling chloromethane gas into the cracking reaction kettle with rising temperature, and preparing methyl chlorosilane mixed monomer; and cooling the mixed monomer, leading the mixed monomer enter a rectifying tower, and then preparing monomethyl dichlorsilane, dimethyl dichlorsilane, monomethyl trichlorosilane and trimethyl monochlorosilane. The method can improve the selectivity of the dimethyl dichlorsilane, increases the product yield, generates less residual waste, solves the problem of the utilization of the high boiling point substance, reduces the environmental pollution, is low in cost, has higher profit space, can be used for continuously cracking the high boiling point substance, and is suitable for popularization and application.

Description

technical field [0001] The invention relates to a production process of organosilicon monomers, in particular to a method for preparing methylchlorosilane by cracking organosilicon high boilers. Background technique [0002] As for the production of methylchlorosilane monomer by pyrolysis of high boilers, there were reports abroad as early as the 1950s. In the early stage, it was mainly thermal cracking, and due to the high reaction temperature, carbon deposition was serious. After entering the 1970s, catalytic cracking gradually replaced thermal cracking and became dominant. People have tried to use various catalysts for cracking reaction, the reaction temperature has been lowered, and the monomer yield has also been improved to varying degrees. According to the difference in the composition of high boilers and the difference in the target products, the catalysts developed and used by various companies are also very different. A large amount of organic silicon waste great...

AI Technical Summary

Problems solved by technology

Among various existing technologies, some methylchlorosilanes have a low conversion rate, some need to be carried out at high temperature and high pressure, resulting in high requirements for equipment, and some use catalysts with high costs.

At present, tri-n-butylamine is generally used as a catalyst in the preparation of methylchlorosilane monomer by using high boilers. Due to the high reaction temperature, the energy consumption is high, and there are many residual wastes, which are harmful to the environment. At the same time, dimethyldichlorosilane The selectivity is around 40%, the selectivity is low