Method for the preparation of silanes

Patent metadata

Field	Value
Publication number	US-9738532-B2
Application number	US-201414782247-A
Country	US
Kind code	B2
Filing date	Feb 28, 2014
Priority date	Apr 24, 2013
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

The invention relates to a process for preparing dimeric and/or trimeric silanes by conversion of monosilane in a plasma and to a plant for performance of the process.

First claim

The invention claimed is:

1. A process for preparing a dimeric and/or trimeric silane of the general formula I:

wherein n=0 or 1, comprising:
i) subjecting a reactant stream comprising monosilane of the general formula II

and hydrogen,

ii) to a gas discharge, and
iii) obtaining the dimeric and/or trimeric silane of the formula I from a resulting phase, and setting a defined ratio of a partial hydrogen pressure to a partial pressure of a silane which is gaseous under a condition selected in the resulting phase;
wherein the defined ratio in process step iii) of the partial hydrogen pressure to the partial pressure of the gaseous silanes is set by a hydrogen-permeable membrane.

2. The process according to claim 1 ,
wherein the pressure in process step iii) is elevated relative to the pressure in process stage ii).

3. The process according to claim 1 ,
wherein the resulting phase in process step iii) has a pressure of 1 bar ab to 100 bar abs .

4. The process according to claim 1 ,
wherein the monosilane in process step ii) is subjected to the gas discharge in the presence of hydrogen at a pressure between 0.05 mbar abs and 15,000 mbar abs .

5. The process according to claim 1 ,
wherein the gas discharge in process step ii) is effected at a pressure between 0.1 mbar abs and 1,000 mbar abs .

6. The process according to claim 1 ,
wherein the gas discharge in process step ii) is effected at a temperature between −60° C. and 10° C.

7. The process according to claim 1 , wherein the reactant stream has a defined ratio of hydrogen and monosilane in percent by volume (% by vol.) of 15:1 to 1:5.

8. The process according to claim 1 , wherein the reactant stream in step ii) is exposed to a nonthermal plasma.

9. The process according to claim 1 ,
wherein the membrane is permeable to hydrogen and essentially impermeable to silanes.

10. The process according to claim 1 ,
wherein said membrane comprises at least one of the following materials: quartz, metal, metallic alloy, ceramic, zeolite, organic polymer and/or a composite membrane having an at least two-layer structure comprising one or more of the aforementioned materials.

11. The process according to claim 1 , wherein the dimeric silane is obtained.

12. The process according to claim 1 , wherein the trimeric silane is obtained.

13. The process according to claim 1 , wherein a mixture of the dimeric and the trimeric silanes is obtained.

Assignees

• Lang Juergen Erwin
• Rauleder Hartwig
• Mueh Ekkehard
• Evonik Degussa Gmbh

Inventors

• Lang Juergen Erwin
• Rauleder Hartwig
• Mueh Ekkehard

Classifications

• C01B33/046

  Purification · CPC title

• B01J2219/0869

  Feeding or evacuating the reactor · CPC title

• C07F7/02

  Silicon compounds · CPC title

• B01J3/006

  Processes utilising sub-atmospheric pressure; Apparatus therefor · CPC title

• B01J2219/0896

  Cold plasma · CPC title