Process for synthesizing (CH3)2 SiCl2 by utilizing CH3 SiCl2

Abstract

The method for synthesizing (CH3)2SiCl2 by utilizing CH3SiCl2 uses methyl trichlorosilane whose purity is greater than 99% and chloromethane whose purity is greater than 98% as raw material, makes them produce gas-phase alkylation reaction, adopts spherical aluminium catalyst whose purity is greater than or equal to 97%, and whose average grain size is 1 mm, and its reactant composite CH3SiCl3:CH3Cl=1:1-1:0.4(mol), controlled reaction temp. is 200-300 deg.C, reaction time is 4-5 hr., CH3SiCl3 conversion rate can be up to above 50%, and per pass total yield rate of (CH3)2SiCl2 and (CH3)3SiCl2 can be up to above 50%.

Description

[0001] Involved areas: [0002] The present invention relates to the synthesis of dimethyldichlorosilane {(CH 3 ) 2 SiCl 2} and trimethylchlorosilane ((CH 3 ) 3 SiCl) method. Background technique: [0003] CH 3 SiCl 3 Can be produced by alkylation (CH 3 ) 2 SiCl 2 , the alkylation reaction generally uses an organoaluminum compound as a catalyst [1] , organoaluminum compounds have a history of more than 100 years, but it was used to synthesize organochlorosilanes after 1983, that is, V.Hnizda (V.Hnizda) and Claus (E.Krans) found that metal aluminum can It starts after directly reacting with halogenated hydrocarbons to form hydrocarbyl aluminum halides. In the 1950s, because Ziegler (K.Ziegler) proposed the industrial production method of alkylaluminum, the development of organosilane synthesis by organoaluminum method was more effectively promoted. The synthesis of organosilane by organoaluminum method can be represented by the following general formula: [0004] ...

AI Technical Summary

Problems solved by technology

[0021] The problem with this method is that the amount of catalyst required for the reaction is very large, generally 10%-20% of the reactant;

[0029] (1) The conversion rate of the alkylation reaction between monomethyltrichlorosilane and methyl chloride and the yield of the target product are all low, CH 3 SiCl 3 Conversion rate is generally between 20-40%, (CH 3 ) 2 SiCl 2 The yield is generally between 10-40%, and the reaction is not easy to control, etc.

[0030] (2) The low-pressure disproportionation reaction of monomethyltrichlorosilane is also difficult to control, and the yield is low, generally below 20%.

[0031] (3) Although the high-pressure disproportionation reaction has a high yield, which can reach 40%, the requirements for the reaction equipment are relatively harsh and the safety is poor

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