Pervaporation separation of volatile siloxanes from emulsions

• US 20020165505A1
• Filed: 03/01/2001
• Published: 11/07/2002
• Est. Priority Date: 03/01/2001
• Status: Abandoned Application

• Current Assignee: Dow Corning Corporation (Dow, Inc.)
• Original Assignee: Dow Corning Corporation (Dow, Inc.)
• Inventors: Gee, Ronald Paul, Wrolson, Burt Michael
• Application Number:
  US09/797,296
• Publication Number:
  US 20020165505A1
• Time in Patent Office: Days
• US Class Current: 604/289
• CPC Class Codes: B01D 61/362 Pervaporation
• CPC Class Codes: C08G 77/34 Purification

Abstract

A method of removing volatile siloxane oligomers from emulsions containing siloxane polymers. The method can be applied to any emulsion containing siloxane polymers, but it'"'"'s especially adapted for removing residual volatile siloxane oligomers from emulsions containing siloxane polymers prepared by emulsion polymerization of the volatile siloxane oligomers. In particular, volatile siloxane oligomers are removed from emulsions containing siloxane polymers by pervaporation.

Claims

1. A method of removing volatile siloxanes from an aqueous emulsion containing siloxane polymers and volatile siloxanes comprising contacting the aqueous emulsion with a hydrophobic pervaporation membrane.

2. A method according to claim 1 in which the volatile siloxanes comprise cyclic siloxanes of the formula

3. A method according to claim 2 in which the cyclic siloxanes comprise hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, or mixtures thereof.

4. An emulsion prepared according to the method defined in claim 1.

5. A method of treating a surface or substrate selected from the group consisting of hair, skin, paper, and textile, comprising applying to the surface or substrate the emulsion prepared according to the method defined in claim 1.

6. A method of removing volatile siloxane oligomers from an aqueous emulsion containing siloxane polymers and volatile siloxane oligomers prepared by emulsion polymerization of the volatile siloxane oligomers comprising contacting the aqueous emulsion with a hydrophobic pervaporation membrane.

7. A method according to claim 6 in which the volatile siloxane oligomers comprise cyclic siloxane monomers of the formula

8. A method according to claim 7, in which the cyclic siloxanes comprise hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, or mixtures thereof.

9. An emulsion prepared according to the method defined in claim 6.

10. A method of treating a surface or substrate selected from the group consisting of hair, skin, paper, and textile, comprising applying to the surface or substrate the emulsion prepared according to the method defined in claim 6.