Hydrosilylation process for gaseous unsaturated hydrocarbons
View Patent ↗Organosilicon compounds are prepared by the addition reaction of a gaseous unsaturated hydrocarbon with a silane or siloxane containing at least one silicon-bonded hydrogen atom in the presence of a hydrosilylation catalyst in a liquid reaction medium. In this process the unsaturated hydrocarbon and optionally the silane or siloxane is dispersed into the liquid reaction medium by a jet eductor (also known as a venturi pump) device and the resultant gas-in-liquid dispersion is introduced into a bubble reactor.
1. A batch or continuous process for producing organosilanes, organohalosilanes, organoalkoxysilanes, and/or organosiloxanes by hydrosilylating gaseous unsaturated hydrocarbons, which comprises:
(a) feeding unsaturated gaseous hydrocarbon (Reagent A) to a reaction zone having a jet eductor and feeding silane (Reagent B) and/or siloxane (Reagent C) containing at least one silicon-bonded hydrogen atom to said reaction zone wherein said Reagent A and said Reagent B and/or Reagent C are contacted with a liquid reaction medium containing a hydrosilylation catalyst and a solvent wherein said liquid reaction medium is pumped through the jet educator nozzle to form a gas-in-liquid dispersion with said Reagent A and said Reagent B and/or Reagent C and to initiate a hydrosilylation reaction,
(b) conducting the gas-in-liquid dispersion to a plug flow gas bubble reaction zone and maintaining gas velocities below 5 centimeters per second for completion of the hydrosilylation reaction to form a hydrosilation reaction product; and
(c) recovering said hydrosilation reaction product from said plug flow gas bubble reaction zone.
2. The process of claim 1 , wherein said Reagent A is terminally unsaturated alkene, halogenated alkene of 1-8 carbon atoms or a mixture thereof.
3. The process of claim 2 , wherein the terminally unsaturated alkene is selected from the group consisting of ethylene, propylene, 1-butene, butadiene, methyl-1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene, and the halogenated alkene is selected from the group consisting of 1,1,1-trifluoropropene, 1,1-difluoroethylene, and 1-chloro-I-fluoroethylene.
4. The process of claim 1 , wherein Reagent A is terminally unsaturated alkyne, halogenated alkyne of 1-8 carbon atoms or mixture thereof.
5. The process of claim 4 , wherein the terminally unsaturated alkyne is selected from the group consisting of acetylene, propyne, 1-butyne, 1-pentyne, 1-hexyne, and 1-octyne and the halogenated alkyne is selected from the group consisting of 3-chloropropyne and 3-chloro-1-butyne.
6. The process of claim 1 , wherein Reagent B possesses the general formula:
R a H b SiX 4-a-b
where R represents a monovalent hydrocarbon radical or substituted monovalent hydrocarbon radical and has 1 to 6 carbon atoms; X represents a halogen or an alkoxy group containing from 1 to 4 carbon atoms; b is 1 or 2; a is 0, 1, 2, or 3; and (a+b) is 1, 2, 3 or 4.
7. The process of claim 6 , wherein Reagent B is selected from the group consisting of trimethoxysilane, triethoxysilane, methyldimethoxysilane, trichlorosilane, methyldichlorosilane, dimethylchlorosilane, trimethylsilane, and mixtures thereof.
8. The process of claim 1 , wherein Reagent C is selected from the group consisting of siloxane of the general formula
R 3 Si(OSiR 2 ) x (OSiHR) y OSiR 3 ,
disiloxane of the general formula:
HR 2 SiOSiR 2 H,
and mixtures thereof wherein in each formula, R is independently substituted or unsubstituted hydrocarbon group containing 1 to 18 carbon atoms, x is less than 20 and y is 5 or less, but not less than 1.
9. The process of claim 8 , wherein Reagent C is selected from the group consisting of heptamethyltrisiloxane, tetramethyldisiloxane and a mixture thereof.
10. The process of claim 1 , further including a promoter.
11. The process of claim 1 , wherein the solvent is selected from the group consisting of the hydrosilylation reaction product, siloxane fluid, organosiloxane fluid, alkane, ether of ethylene glycol, ether of diethylene glycol, ether of triethylene glycol, ether of tetraethylene glycol, ether of propylene glycol, cumene, toluene, xylene, o-dichlorobenzene, and mixtures thereof.
12. The process of claim 11 , wherein the hydrosilylation reaction product is vinylchlorosilane, vinylalkoxysilane, bis(chlorosilyl)alkane, bis(alkoxysilyl)alkane or mixtures thereof.
13. The process of claim 11 , wherein the siloxane fluid solvent is selected from the group consisting of linear dimethylsiloxane and cyclic polydimethylsiloxane, and the alkane is selected from the group consisting of heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, and mixtures thereof.
14. The process of claim 1 , wherein the silane or siloxane is a liquid or gas premixed with the gaseous hydrocarbon before feeding to the jet eductor reaction zone.
15. The process of claim 1 , wherein the silane or siloxane is a liquid or gas premixed with the reaction medium prior to introduction to the jet eductor reaction zone.
16. The process of claim 1 , wherein the reaction is carried out at a temperature between about 120° C. and about 180° C.
17. The process of claim 1 , wherein the reaction is carried out at a temperature between about 50° C. and about 130° C.
18. The process of claim 1 , wherein said reaction zone is at a pressure of less than about 41 atmospheres gauge (600 psig).
19. The process of claim 1 , wherein the hydrosilylation reaction product is removed from the reaction zone as a gas or a liquid or mixture thereof.
20. The process of claim 1 , wherein a feed molar ratio for Reagent A to Reagent B or Reagent C or mixture of Reagent B and Reagent C of greater than 1 per silicon-bonded hydrogen atom site on said Reagent B or Reagent C is maintained.