Process for removing an impurity from a siloxane
View Patent ↗A process for removing an impurity from a siloxane comprising i) flowing a first liquid through a fiber bundle comprising a plurality of fibers extending lengthwise in a conduit, wherein the bundle has an upstream end and a downstream end, and the first liquid flows in a direction from the upstream end of the bundle to the downstream end; and ii) while continuing (i), flowing a second liquid comprising a siloxane and an impurity through the fiber bundle in a direction from the upstream end of the bundle to the downstream end of the bundle to effect transfer of at least a portion of the impurity from the second liquid to the first liquid, wherein the first liquid and the second liquid are substantially immiscible.
1. A process for removing an impurity from a siloxane, the process comprising:
i) flowing a first liquid through a fiber bundle comprising a plurality of fibers extending lengthwise in a conduit, wherein the bundle has an upstream end and a downstream end, and the first liquid flows in a direction from the upstream end of the bundle to the downstream end; and
ii) while continuing (i), flowing a second liquid comprising a siloxane and an impurity through the fiber bundle in a direction from the upstream end of the bundle to the downstream end of the bundle to effect transfer of at least a portion of the impurity from the second liquid to the first liquid, wherein the first liquid and the second liquid are substantially immiscible.
2. The process of claim 1 , further comprising (iii) receiving the first liquid and the second liquid in a collection vessel, wherein the first liquid forms a first layer and the second liquid forms a second layer in the collection vessel.
3. The process of claim 1 , wherein the siloxane is a silicone fluid or silicon resin.
4. The process of claim 1 , wherein the impurity is an acid, a salt, or an ion.
5. The process of claim 4 , wherein the impurity is an acid selected from hydrogen chloride, hydrogen bromide, hydrogen fluoride, hydrogen iodide, and trifluoromethane sulfonic acid.
6. The process of claim 5 , wherein the impurity is hydrogen chloride.
7. The process of claim 4 wherein the impurity is sodium chloride.
8. The process of claim 4 wherein the impurity is a chloride ion.
9. The process of claim 1 , wherein the second liquid comprises from 50 to 1,500 ppmw of the impurity.
10. The process of claim 1 , wherein the first liquid and second liquid are at a temperature from 15 to 60 ° C.
11. The process of claim 1 , wherein the fibers comprise cotton, jute, silk, treated minerals, untreated minerals, metals, metal alloys, treated carbon, untreated carbon, polymers, or polymer blends.
12. The process of claim 11 , wherein the fibers are glass or steel fibers.
13. The process of claim 1 , wherein the first liquid comprises water.
14. The process of claim 1 , wherein the siloxane is formed by the hydrolysis of R a SiX 4−a , wherein each R is independently H or a monovalent organic group, X is C 1 —C 8 alkoxy or halo, and a is an integer from 0 to 3.
15. The process according to claim 14 , wherein each R is independently methyl or hydrogen and X is chloro.
16. The process of claim 1 , wherein the volumetric flow ratio of the second liquid to the first liquid is from 1 to 4.
17. The process of claim 1 , wherein the fibers have a diameter from 5 to 25μm.
18. The process of claim 1 , wherein the first liquid and second liquid have a residence time from 5 seconds to 30 minutes.
19. The process of claim 1 , wherein the second liquid further comprises a non-polar solvent.
20. The process of claim 1 , wherein the first liquid has a viscosity from 0.1 to 100 cSt, at 25 ° C., and wherein the second liquid has a viscosity from 0.1 to 100 cSt, at 25 ° C.
21. The process of claim 13 , wherein the first liquid is aqueous HCl.