Process for making trisilylamine

Patent metadata

Field	Value
Publication number	US-9284198-B2
Application number	US-201414284983-A
Country	US
Kind code	B2
Filing date	May 22, 2014
Priority date	Jun 28, 2013
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

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.

First claim

The invention claimed is:

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.

Assignees

• Air Prod & Chem

Inventors

• Agarwal Rajiv Krishan
• Lo Sai-Hong Andrew
• Withers Jr Howard Paul
• Sluzevich Joseph T
• Hart James Joseph

Classifications

• C01C1/164 Primary

  Ammonium chloride · CPC title

• C01B21/087 Primary

  containing one or more hydrogen atoms · CPC title

• B01J2208/00823

  Mixing elements · CPC title

• B01J2208/00761

  Discharging · CPC title

• B01J8/24

  according to "fluidised-bed" technique (B01J8/20 takes precedence) · CPC title