Continuous process for polymerization and emulsification of siloxane

1. A continuous process of making a silicone-in-water emulsion in an extruder, comprising:

(i) forming a silicone polymer having a viscosity of at least 10,000 mm 2 /s at 25° C. by polymerization of one or more polyorganosiloxanes in the extruder;

wherein polymerization is selected from (a) condensation polymerization of at least one polyorganosiloxane having at least one hydroxyl group capable of undergoing condensation polymerization; (b) ring-opening polymerization of at least one cyclosiloxane; (c) addition polymerization of a mixture of at least one polyorganosiloxane having at least one unsaturated aliphatic group and at least one hydrogen-terminated polyorganosiloxane; and (d) combinations thereof;

wherein one or more catalysts, optionally one or more endblockers, and optionally one or more other additives are mixed with the polyorganosiloxanes;

wherein polymerization is carried out in the absence of solvent other than solvents used as carriers for the catalysts, optional endblockers, and optional additives;

(ii) optionally, neutralizing or stripping the silicone polymer in the extruder, wherein stripping can occur before, after, or without addition of a neutralizing agent;

(iii) cooling the silicone polymer in a cooling zone of the extruder at a temperature between about 0° C. and about 60° C.;

(iv) optionally, mixing one or more emulsifiers with the silicone polymer in the extruder;

(v) optionally, adding water to the silicone polymer in the extruder;

(vi) applying shear to form a silicone-in-water emulsion in the extruder;

wherein the emulsion has a silicone polymer; wherein the emulsion has 0-0.3% by weight of at least one of octamethylcyclotetrasiloxanes and decamethylcyclopentasiloxanes; and

(vii) optionally, diluting the emulsion in the extruder;

wherein the extruder is selected from single-screw extruders and multi-screw extruders.

2. The process of claim 1 , wherein the silicone polymer is formed by condensation polymerization of at least one polyorganosiloxane having a viscosity of from about 40 mm 2 /s to about 100 mm 2 /s at 25° C.

3. The process of claim 2 , wherein the polyorganosiloxanes are characterized by formula (1):

R 1 O[R 2 R 3 SiO] x H  (1)

wherein R 1 , R 2 , and R 3 are independently selected from a hydrogen atom; an alkyl or substituted alkyl group containing up to 8 carbon atoms; an aryl or substituted aryl group containing up to 8 carbon atoms; and

wherein x is an integer with a value of from 2-80.

4. The process of claim 3 , wherein each R 1 , R 2 , and R 3 is independently selected from methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, iso-butyl, and tert-butyl.

5. The process of claim 3 , wherein the polyorganosiloxanes are polydimethylsiloxanes.

6. The process of claim 1 , wherein the silicone polymer is formed by ring-opening polymerization of at least one cyclosiloxane having a viscosity of from about 1 mm 2 /s to about 5 mm 2 /s at 25° C.

7. The process of claim 6 , wherein the cyclosiloxanes are characterized by formula (2):

[R 1 R 2 SiO] x   (2)

wherein R 1 and R 2 are independently selected from a hydrogen atom; an optionally substituted alkyl, alkenyl, aryl, alkaryl, or aralkyl group containing up to 8 carbon atoms; methyl; ethyl; n-propyl; trifluoropropyl; isopropyl; n-butyl; sec-butyl; iso-butyl; tert-butyl; vinyl; allyl; propenyl; butenyl; phenyl; tolyl; and benzoyl; and wherein x is an integer with a value of from 3 to 12.

8. The process of claim 7 , wherein the cyclosiloxanes are selected from octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, decamethylcyclopentasiloxane, cyclopenta(methylvinyl)siloxane, cyclotetra(phenylmethyl)siloxane, and cyclopentamethylhydrosiloxane.

9. The process of claim 1 , wherein the silicone polymer is formed by addition polymerization of polyorganosiloxanes having a viscosity of from about 8 mm 2 /s to about 55,000 mm 2 /s at 25° C.

10. The process of claim 1 , wherein the polyorganosiloxane is selected from linear polyorganosiloxanes or substantially linear polyorganosiloxanes.

11. The process of claim 10 , wherein the polyorganosiloxanes are characterized by formula (3):

R 1 O—[R 2 R 3 SiO] x R 4   (3)

wherein R 1 , R 2 , R 3 , and R 4 are independently selected from a hydrogen atom; an alkyl or substituted alkyl group containing up to 8 carbon atoms; an alkenyl or substituted alkenyl group containing up to 8 carbon atoms; an alkynyl or substituted alkynyl group containing up to 8 carbon atoms; an aryl or substituted aryl group containing up to 8 carbon atoms; substituted or unsubstituted vinyl; propenyl; butenyl; ethynyl; propynyl; and butyryl; and

wherein x is an integer with a value of from 2 to 1300.

12. The process of claim 1 , wherein the one or more catalysts is selected from phosphonitrile chloride, polydimethylaminophosphazenium hydroxide, and a platinum catalyst.

13. The process of claim 1 , wherein the neutralization agent is selected from triethanolamine, trihexylamine, and trimethylsilyl vinylphosphonic acid.

14. The process of claim 1 , wherein the silicone-in-water emulsion has an octamethylcyclotetrasiloxane content of from about 0% to about 0.3% by weight.

15. The process of claim 1 , wherein the silicone-in-water emulsion has a decamethylcyclopentasiloxane content of from about 0% to about 0.3% by weight.

16. The process of claim 1 , wherein the silicone-in-water emulsion comprises a silicone polymer having a viscosity of from about 10,000 mm 2 /s to about 200,000,000 mm 2 /s at 25° C.

17. The process of claim 16 , wherein the silicone-in-water emulsion comprises a silicone polymer having a viscosity of from about 80,000 mm 2 /s to about 10,000,000 mm 2 /s at 25° C.

18. The process of claim 16 , wherein the silicone-in-water emulsion comprises a silicone polymer having a viscosity of from about 1,200,000 mm 2 /s to about 175,000,000 mm 2 /s at 25° C.

19. The process of claim 1 , wherein the silicone-in-water emulsion has an average particle size of from about 0.1 micrometers to about 25 micrometers.

20. The process of claim 1 , wherein the silicone polymer is neutralized or stripped in the extruder.

21. The process of claim 1 , wherein one or more emulsifiers are mixed with the silicone polymer in the extruder.

22. The process of claim 1 , wherein water is added to the silicone polymer in the extruder.