EP0175282A2
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EP
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Direct process for preparing siloxanes
Assignee: Union Carbide Corp
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Filing: 1985-09-12
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Granted: —
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Expires: 2005-09-12
Abstract
Abstract A process is disclosed for the direct synthesis of cyclic and oligomeric organosiloxanes, such as dimethylsiloxanes, comprising reacting a hydrocarbon ether and a hydrocarbon halide with a fluidized or agitated bed of activated silicon particles with a maximum contact time of five minutes, and continuously withdrawing products from that reaction.
Inventors
- 👤 Kenrick Martin Lewis
- 👤 Bernard Kanner
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 04:54
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/18; C07F7/0834; C07F7/0838; C07F7/0872; C07F7/0874; C07F7/12; C07F7/16; C07F7/1804; C07F7/1872; C07F7/21
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
42 words
A process for preparing cyclic and oligomeric organosiloxanes comprising reacting a hydrocarbon ether and a hydrocarbon halide with a fluidized or agitated bed of activated silicon particles at a maximum contact time of 5 minutes, and continuously withdrawing products from said reaction.
Claim 2
Dependent Claim
42 words
A process for preparing cyclic and oligomeric organosiloxanes comprising reacting a hydrocarbon ether and a hydrocarbon halide with a fluidized or agitated bed of activated silicon particles at a maximum contact time of 5 minutes, and continuously withdrawing products from said reaction.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the reaction is conducted at a temperature greater than the boiling points of the reactants and products.
Claim 4
Dependent Claim
14 words
The process of claim 2 wherein the temperature is 250-400 °C o.r 325-360° C.
Claim 5
Dependent Claim
23 words
The process of claim 3 wherein the reaction is conducted at atmospheric pressure or at a super-atmospheric pressure up to about 4,14 bar.
Claim 6
Dependent Claim
17 words
The process of claims 1 to 4 wherein the silicon particles are activated with copper and/or silber.
Claim 7
Dependent Claim
27 words
The process of claim 5 wherein the copper-activated silicon particles are prepared by heating mixtures of copper oxides and silicon metal in the presence of hydrogen chloride.
Claim 8
Dependent Claim
18 words
The process of claim 6 wherein the activation reaction is conducted at a temperature above about 300 °C.
Claim 9
Dependent Claim
34 words
The process of claims 5 to 7 wherein the amount of copper in the activated silicon particles is less than about 10% or 0,5 to 3% by weight, based on the weight of silicon.
Claim 10
Dependent Claim
20 words
The process of claims 1 to 8 wherein the particle size of the activated silicon particles is smaller than 300µm.
Claim 11
Dependent Claim
31 words
The process of claims 1 to 9 wherein the reaction is conducted in the presence of an additive selected from zinc powder, anhydrous ZnCl 2 , ZnO and ZnC0 3 .
Claim 12
Dependent Claim
12 words
The process of claims 1 to 10 wherein the organosilanes are dimethylsiloxanes.
Claim 13
Dependent Claim
68 words
The process of claims 1 to 11 wherein the hydrocarbon ether is a compound represented by the formula R 1 -O-R 2 wherein R 1 and R 2 , which may be the same or different, each represent a saturated or unsaturated aliphatic hydrocarbon radical or an aromatic hydrocarbon radical, with the proviso that at least one of R 1 and R 2 is an aliphatic hydrocarbon radical.
Claim 14
Dependent Claim
25 words
The process of claim 12 wherein R 1 and R 2 are the same monovalent aliphatic hydrocarbon radical having from 1 to 6 carbon atoms.
Claim 15
Dependent Claim
12 words
The process of claim 13 wherein the hydrocarbon ether is dimethyl ether.
Claim 16
Dependent Claim
43 words
The process of claims 1 to 14 wherein the hydrocarbon halide is a compound represented by the formula R 3 X wherein R 3 represents a saturated or unsaturated aliphatic hydrocarbon radical or an aromatic hydrocarbon radical, and X represents a halogen atom.
Claim 17
Dependent Claim
16 words
The process of claim 15 wherein R 3 is selected from alkyl, vinyl and phenyl radicals.
Claim 18
Dependent Claim
15 words
The process of claim 6 wherein the hydrocarbon halide is methyl chloride or methyl bromide.
Claim 19
Dependent Claim
29 words
The process of claims 1 to 17 wherein gaseous hydrocarbon ether and hydrocarbon halide are fed to the reaction in an amount sufficient to fluidize the activated silicon particles.
Claim 20
Dependent Claim
24 words
The process of claim 18 wherein the amount is at least that amount necessary to provide a linear fluidization velocity of about 0.15 cm/s.
Claim 21
Dependent Claim
27 words
The process of claims 1 to 19 wherein the hydrocarbon halide and the hydrocarbon ehter are mixed and then the resulting mixture is fed to the reaction.
Claim 22
Dependent Claim
19 words
The process of claims 1 to 20 wherein the reaction contact time is from 5 seconds to 5 minutes.
Claim 23
Dependent Claim
24 words
The process of claims 1 to 21 wherein the molar proportion of hydrocarbon halide:hydrocarbon ether is from 1:1 to 6:1 or 1:1 to 2:1.
Claim 24
Dependent Claim
17 words
The process of claims 1 to 22 further comprising recycling the gas reaction product to the reaction.
Claim 25
Dependent Claim
38 words
The process of claim 23 wherein the gas reaction product is reconstituted with additional hydrocarbon halide and hydrocarbon ether to obtain a gas mixture having the molar ratio of claim 22 and thereafter is recycled to the reaction.
References Cited (Backward Citations)
No citation records indexed.
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