Method for preparing monochloromethyl trichlorosilane

Abstract

The invention relates to a method for preparing monochloromethyl trichlorosilane, belonging to the technical field of organic synthesis. The preparation method comprises the following steps: after CH3SiCl3 reflux in an evaporation kettle becomes stable, introducing chlorine to below the CH3SiCl3 liquid level; heating the gas mixture from the evaporation kettle, and sending the gas mixture into a reaction region; irradiating the reaction region by white light or ultraviolet light; condensing the material from the reaction region, and refluxing the high-boiling-point liquid material to the heating region; when the temperature of the material in the evaporation kettle reaches 100-108 DEG C, stopping reaction; and after the reaction finishes, closing a valve above a packing tower, directly carrying out normal pressure rectification on the material in the evaporation kettle, and collecting the 117-118.5-DEG C fraction to obtain monochloromethyl trichlorosilane. The chlorine is introduced to below the CH3SiCl3 liquid level in the evaporation kettle, thereby ensuring that the chlorine and methyl trichlorosilane can be thoroughly mixed to form the uniform gas mixture. The method can effectively control the Cl2 / CH3SiCl3 mole ratio, thereby enhancing the conversion rate of the monochloromethyl trichlorosilane.

Description

technical field [0001] The invention relates to a method for preparing monochloromethyltrichlorosilane, which belongs to the technical field of organic synthesis. Background technique [0002] Chloromethyltrichlorosilane is the most important raw material for the preparation of α-functional silane coupling agents. Compared with (traditional) γ-functional silane coupling agents, α-functional silane coupling agents have readily available raw materials and properties Lively, good heat resistance and other advantages, with a wider range of applications. [0003] Scholars from various countries have studied the synthesis of ClCH by chlorination 2 SiCl 3 A variety of methods have been tried, mainly liquid-phase chlorination, gas-phase photochlorination, and gas-phase thermal chlorination. [0004] When using azobisisobutyronitrile as the liquid phase method of the initiator, the product ClCH 2 SiCl 3 , Cl 2 CHSiCl 3 The chlorination rate is faster than that of CH 3 SiCl 3...

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Problems solved by technology

[0009] In 2001, Jiang Biao, Xie Deliang and others reported "Method and device for preparing chloromethylchlorosilane by gas phase chlorination" (public number: CN1317488A), and provided a preparation method of chloromethylchlorosilane: the molecular formula is CH 3 Si(CH 3 ) m Cl 3-m The methyl chlorosilane as raw material, the Cl 2 It is directly passed into the reaction zone, mixed with the gasified raw material gas, and the gas-phase chlorination reaction is carried out only by indoor general visible light irradiation, so as to obtain higher yields of chloromethylchlorosilane. According to reports, the molar ratio of raw material gas to chlorine gas is 1: 0.1~0.75, the reaction temperature is 50~80℃, and the reaction time is 1~24h, but this method and equipment still face many problems: chlorine gas directly enters the reaction zone, and the amount of reactants is not easy to control; according to the patent description, a There is no distinction between chlorinated products and polychlorinated products, only the total conversion rate of chlorination reaction is pursued; the reaction time is too long; the surface of the reactor must be cleaned regularly to remove the generated polymer; in some cases it is possible Spontaneous combustion or explosion of the reactants occurs; after the reaction, the product needs to be moved to the still for difficult distillation separation

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