Production of trisilylamine from monochlorosilane and ammonia by use of inert solvent

1. Process for production of trisilylamine in the liquid phase,

which process comprises

initially charging monochlorosilane (A or A′) to a reactor ( 1 ) in the liquid form of a solution in a solvent (H), wherein the solvent is inert with regard to monochlorosilane, ammonia as well as TSA and has a higher boiling point than TSA has, and

passing ammonia (B) into the reactor in the form of a solution in the solvent (H),

performing the reaction in reactor ( 1 ),

subsequently passing the resultant product mixture from reactor ( 1 ) into and through a filter unit ( 2 ) and removing solid ammonium chloride (C) from the product mixture, and

passing the filtrate from the filter unit ( 2 ) into the distillation column ( 3 ),

excess monochlorosilane (A′) being distilled in distillation column ( 3 ) overhead, condensed and fed to reactor ( 1 ) in liquid form under admixture of the solvent, and also

removing gaseous substances (D) from the distillation column ( 3 ) overhead, and

conveying the bottoms (E) into the distillation column ( 4 ),

the product trisilylamine (G) being distilled in the distillation column ( 4 ) overhead and condensed, and

conveying the bottoms (F) into the distillation column ( 5 ),

the solvent (H) being distilled in distillation column ( 5 ) overhead, condensed and returned to the reactor feedstreams (A), (A′), (B) as a solvent, and

exporting higher boilers via the bottoms (I).

2. Process according to claim 1 , characterized in that component (A or A′) is used in a molar stoichiometric excess relative to component (B).

3. Process according to claim 1 , characterized in that the reactor ( 1 ) is filled with the reaction mixture of components (A, A′), (B) and also (H) as solvent up to 99% of the reactor volume to perform the reaction.

4. Process according to claim 1 , characterized in that the reaction in reactor ( 1 ) is carried out at temperature of −60 to +40° C.

5. Process according to claim 1 , characterized in that the process is carried out batchwise or continuously.

6. Process according to claim 1 , wherein the solvent (H) is toluene.

7. Plant for reacting at least the reactants monohalosilane (A, A′) and ammonia (B) with the solvent (H) in the liquid phase to form a product mixture for production of trisilylamine comprising

a reactor ( 1 ) with feeds for the components (A), (A′), (B) and also (H) as solvent and a product mixture outlet opening into a

filter unit ( 2 ) which is connected to reactor ( 1 ) at the downstream end thereof and which in turn is equipped with a solids outlet for component (C) and with a line for conveying the filtrate out of unit ( 2 ) into

a subsequent distillation unit which consists of at least three distillation columns ( 3 ), ( 4 ) and ( 5 ) and the distillation column ( 3 ) is equipped with an outlet overhead for a gaseous stream (D) and with an outlet overhead with a return line for condensed monochlorosilane (A′) into the reactor ( 1 ) under admixture of solvent (H) and also with a line for transferring bottoms (E) from the distillation column ( 3 ) into the subsequent distillation column ( 4 ) to recover trisilylamine (G) and also with a line for transferring bottoms (F) from the distillation column ( 4 ) into the subsequent distillation column ( 5 ) to recover solvent (H) and also export bottoms (I).

8. Plant according to claim 7 , wherein the solvent (H) is toluene.