Method of preparing an organohalosilane

Patent metadata

Field	Value
Publication number	US-9296765-B2
Application number	US-201314419967-A
Country	US
Kind code	B2
Filing date	Aug 13, 2013
Priority date	Aug 13, 2012
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

The application relates to a method for preparing organohalosilanes in a two-step process: Steps (i) contacting a copper catalyst with hydrogen gas and halogenated silanes forming a silicon-containing copper catalyst; and Step (ii) contacting said silicon-containing copper catalyst with an organohalide to form the organohalosilane.

First claim

That which is claimed is:

1. A method of preparing at least one organohalosilane, the method comprising the following separate and consecutive steps:
a first step [Rxn (i)] of contacting a copper catalyst with a mixture comprising hydrogen (H2) gas and one or more halogenated silane monomers; wherein the residence time of the copper catalyst being in contact with the hydrogen gas and halogenated silane monomers is from 0.1 second to 45 minutes at a temperature between 500° C. and 950° C. to form a silicon-containing copper catalyst comprising at least 0.1% (w/w) of silicon; and
a second step [Rxn (ii)] of contacting the silicon-containing copper catalyst with an organohalide at a temperature of from 100° C. to 600° C. to form at least one organohalosilane;
wherein the halogenated silane monomers include RSiX3, HSiX3, or a mixture thereof; and optionally with SiX4 being added thereto, such that R is an alkyl group having between 1 to 10 carbon atoms and X is independently selected as a chloro, bromo, fluoro, or iodo group;
wherein the copper catalyst is selected from copper and a mixture comprising copper and at least one element selected from gold, magnesium, calcium, cesium, tin, nickel, and sulfur; and
wherein the organohalosilane is a diorganodihalosilane.

2. The method of claim 1 , wherein the optional SiX4 added as part of the halogenated silane monomers is silicon tetrachloride.

3. The method of claim 1 , further comprising a third step [Rxn(iii)] in which the separate and consecutive first and second steps are repeated one or more times.

4. A method of preparing at least one organohalosilane, the method comprising the following separate and consecutive steps:
a first step [Rxn (i)] of contacting a copper catalyst with a mixture comprising hydrogen (H2) gas and one or more halogenated silane monomers at a temperature of from 500° C. to 1400° C. to form a silicon-containing copper catalyst comprising at least 0.1% (w/w) of silicon; and

a second step [Rxn (ii)] of contacting the silicon-containing copper catalyst with an organohalide at a temperature of from 100° C. to 600° C. to form at least one organohalosilane;
wherein the halogenated silane monomers include RSiX3, HSiX3, or a mixture thereof; and optionally with SiX4 being added thereto, such that R is an alkyl group having between 1 to 10 carbon atoms and X is independently selected as a chloro, bromo, fluoro, or iodo group;
wherein the copper catalyst is selected from copper and a mixture comprising copper and at least one element selected from gold, magnesium, calcium, cesium, tin, nickel, and sulfur; and
wherein the organohalosilane is a diorganodihalosilane; and

purging the silicon-containing copper catalyst formed in Rxn (i) with at least one of hydrogen gas or an inert gas prior to the contacting said catalyst with the organohalide in Rxn (ii).

5. The method according to claim 4 , wherein the silicon-containing copper catalyst is first purged with hydrogen gas and then subsequently purged with an inert gas.

6. The method of claim 1 , wherein the copper catalyst comprises copper in an amount between 0.1 to 80% (w/w) of the total weight of the catalyst.

7. The method of claim 1 , wherein the copper catalyst further includes a metal oxide or carbon-based support.

8. The method of claim 1 , wherein the copper catalyst comprises copper and nickel.

9. The method according to claim 6 , wherein the support is activated carbon.

10. The method of claim 1 , wherein the silicon-containing copper catalyst formed in Rxn (i) comprises from 0.1 to 55% (w/w) of silicon based on the total weight of the silicon-containing copper catalyst.

11. The method of claim 1 , wherein the mole ratio of hydrogen gas to halogenated silane monomers including any optional SiX4 is from 10:1 to 1:1.

12. The method of claim 1 , wherein in the halogenated silane monomers, the R is a methyl group and X is a chloro group.

13. The method of claim 1 , wherein the organohalide has the formula R′X′, where R′ is a C1-C10 alkyl group or a C4-C10 cycloalkyl group, and X′ is a chloro, bromo, fluoro, or iodo group.

14. The method of claim 13 , wherein R′ is a methyl group and X′ is a chloro group.

15. The method of claim 1 , wherein the organohalosilane has the formula R″2SiX″2, where R″ is a C1-C10 alkyl group or a C4-C10 cycloalkyl group, and X″ is a fluoro, chloro, bromo, or iodo group.

16. The method according to claim 15 , wherein R″ is a methyl group and X″ is a chloro group.

17. The method of claim 1 , further comprising the step of recovering the organohalosilane.

18. A method comprising the following separate and consecutive steps:
a first step [Rxn (i)] of contacting a copper catalyst with a mixture comprising hydrogen (H2) gas and one or more halogenated silane monomers; wherein the residence time of the copper catalyst being in contact with the hydrogen gas and halogenated silane monomers is from 0.1 second to 45 minutes at a temperature between 500° C. and 950° C. to form a silicon-containing copper catalyst comprising at least 0.1% (w/w) of silicon; and
a second step [Rxn (ii)] of contacting the silicon-containing copper catalyst with an organohalide at a temperature of from 100° C. to 600° C. to form at least one organohalosilane;
wherein the halogenated silane monomers include RSiX3, HSiX3, or a mixture thereof; and optionally with SiX4 being added thereto, such that R is an alkyl group having between 1 to 10 carbon atoms and X is independently selected as a chloro, bromo, fluoro, or iodo group;
wherein the copper catalyst is selected from copper and a mixture comprising copper and at least one element selected from gold, magnesium, calcium, cesium, tin, nickel, and sulfur, and
wherein the organohalosilane is a diorganodihalosilane;
wherein the method further comprises the step of hydrolyzing the organohalosilane to form a polyorganosiloxane.

Assignees

• Dow Corning

Inventors

• Coppernoll Aaron
• Horner Catharine
• Janmanchi Krishna
• Katsoulis Dimitris
• Larsen Robert

Classifications

• C07F7/122 Primary

  by reactions involving the formation of Si-C linkages (hydrosilylation reactions C07F7/14; direct synthesis C07F7/16) · CPC title

• C08G77/04

  Polysiloxanes · CPC title

• B01J23/755

  Nickel · CPC title

• B01J23/72

  Copper · CPC title