Process for making trisilylamine
View Patent ↗The method described herein provides a method for preparing trisilylamine. In one aspect, the method comprises: providing a reaction mixture of trisilylamine and monochlorosilane into a reactor wherein the reaction mixture is at a temperature and pressure sufficient to provide trisilylamine in a liquid phase wherein the reaction mixture is substantially free of an added solvent; contacting the reaction mixture with ammonia to provide a crude mixture comprising trisilylamine and an ammonium chloride solid wherein monochlorosilane is in stoichiometric excess in relation to ammonia; purifiying the crude mixture to provide trisilylamine wherein the trisilyamine is produced at purity level of 90% or greater; and optionally removing the ammonium chloride solid from the reactor.
1. A method for preparing trisilylamine, the method comprising:
providing a reaction mixture of trisilylamine and monochlorosilane into a reactor wherein the reaction mixture is at a temperature and pressure sufficient to provide trisilylamine in a liquid phase wherein the reaction mixture is substantially free of an added solvent and wherein the density of trisilyamine in the reactor ranges from about 1.5 to about 100 grams/liter;
contacting the reaction mixture with ammonia to provide a crude mixture comprising trisilylamine and an ammonium chloride solid wherein monochlorosilane is in stoichiometric excess in relation to ammonia;
purifiying the crude mixture to provide trisilylamine wherein the trisilyamine is produced at purity level of 90% or greater; and
optionally removing the ammonium chloride solid from the reactor.
2. The method of claim 1 wherein the reactor is selected from a batch reactor or a continuous stirred tank reactor.
3. The method of claim 1 wherein the reactor comprises the batch reactor.
4. The method of claim 3 wherein the monochlorosilane is added to the reaction mixture in the batch reactor before the contacting step.
5. The method of claim 3 wherein the density of trisilylamine in the batch reactor comprises about 1.7 g/l or greater.
6. The method of claim 1 wherein the reactor comprises the continuous stirred tank reactor.
7. The method of claim 6 wherein the trisilylamine is added as a solvent in the providing step.
8. The method of claim 1 wherein the process comprises removing the ammonium chloride solid from the reactor.
9. The method of claim 8 wherein the removing step comprises in situ vacuum removal.
10. The method of claim 8 wherein an inert gas is used to fluidize the ammonium chloride solids in the reactor.
11. The method of claim 10 wherein the fluidized solids are carried out to a venturi vacuum system via the inert gas for collection and disposal.
12. The method of claim 1 wherein the temperature ranges from 20 to 120° C.
13. The method of claim 1 wherein the pressure ranges from 0.1 to 115 psia.
14. The method of claim 1 wherein the crude mixture is removed from the reactor via evaporation to a collector.
15. The method of claim 1 wherein the crude mixture is removed from the reactor via evaporation to a distillation column.
16. The method of claim 1 wherein the trisilylamine is purified during the purifying step to a purity level of 99% or greater.
17. The method of claim 1 wherein the polysilazanes are removed from the reactor by evaporation and collection.
18. The method of claim 1 wherein the reaction mixture comprises more up to 30% by weight stoichiometric excess monochlorosilane relative to ammonia.
19. The method of claim 1 wherein the reaction mixture comprises from about 3% to about 5% by weight stoichiometric excess monochlorosilane relative to ammonia.