METHOD FOR THE COUPLED PRODUCTION OF TRISILYLAMINE AND POLYSILAZANES HAVING A MOLAR MASS OF UP TO 500 G/MOL

摘要

The invention relates to a method for producing trisilylamine and polysilazanes in the liquid phase by adding ammonia in an overstoichiometric amount in relation to monochlorosilane that is present in an inert solvent. A reaction takes place in which trisilylamine and polysilazanes are produced. TSA is then separated out of the product mixture in gaseous form. The TSA obtained is purified by filtration and distillation and obtained at a high or ultra-high level of purity. The bottom product mixture is conducted out of the reactor through a filter unit, solid ammonium chloride being separated out, and a liquid mixture of polysilazanes and solvent is obtained. Said mixture is fed to a further distillation stage in order to recover solvent. The stoichiometric overdosing of NH3 in relation to monochlorosilane means that all the monochlorosilane in the reactor is reacted. This completely prevents the reaction of monochlorosilane with additional disilylamine, which is formed in small amounts, to form solid ammonium chloride in the downstream system parts for purifying the TSA. The solutions filtered downstream of the reactor are correspondingly completely free of solids. The distillation columns used do not contain any solids or deposits at all after the distillation processes are complete.