Preparation method for high-purity methylphenyl-dimethoxysilane

Abstract

The invention relates to a preparation method for high-purity methylphenyl-dimethoxysilane. The preparation method is characterized in that high-purity methylphenyl-dimethoxysilane is prepared through four-step deacidification. The method comprises the following steps: 1) adding dichloromethyl phenylsilane and a hydrogen chloride absorbent into an alcoholysis enclosed agitation reactor, then slowly adding a mixed liquor of absolute methanol and a catalyst drop by drop, controlling a certain reaction temperature, carrying out reflux deacidification at a certain temperature after completion of dropwise addition, carrying out filtering after complete reaction so as to obtain a crude methylphenyl-dimethoxysilane product and recovering the tail gas--hydrogen chloride gas by using a falling film absorption system for preparation of hydrochloric acid; and 2) adding the crude methylphenyl-dimethoxysilane product into a self-made gradient high-efficiency rectifying tower bottom, controlling rectification temperature for fractionation and recovery of methanol and adjusting a reflux ratio to rectify high-quality methylphenyl-dimethoxysilane with quality reaching an international advanced level. The preparation method for methylphenyl-dimethoxysilane has the advantages of environment friendliness, cyclic utilization of resources, stable process, simple operation and product purity of more than 99.5%.

Description

technical field [0001] The invention relates to a synthetic monomer of an organic silicon packaging material, in particular to a method for preparing high-purity methylphenyldimethoxysilane by adopting a four-step deacidification method. Background technique [0002] During the "Twelfth Five-Year Plan" period, strategic emerging industries are the country's key development direction, and the energy-saving and environmental protection industry represented by LED is one of the important development areas. With the development of high-power and white LEDs, high refractive index, high transparency, and high weather resistance have become the must-have properties of LED packaging materials. At present, only silicone materials, especially phenyl silicone materials, can meet the requirements of high-power, white-light LED packaging materials with high refractive index, high transparency, and high weather resistance. Methylphenyldimethoxysilane is the most ideal and most important ...

AI Technical Summary

Problems solved by technology

Since part of the hydrogen chloride will be dissolved in the methylphenyldimethoxysilane, a series of polymerization side reactions will be triggered, resulting in high boiling substances, which will reduce the yield. At the same time, a large amount of hydrogen chloride gas will be generated during the alcoholysis process, which will seriously affect the tail gas post-treatment. technical difficulties, polluting the environment

Because the traditional alcoholysis process cannot discharge hydrogen chloride in time, and the rectification technology is defective, high-purity methylphenyldimethoxysilane cannot be obtained

Images