PROCESS FOR MAKING SILICONE-IN-WATER EMULSIONS

• US 20080242744A1
• Filed: 05/01/2008
• Published: 10/02/2008
• Est. Priority Date: 07/23/2003
• Status: Abandoned Application

• Current Assignee: Dow, Inc.
• Original Assignee: Dow, Inc.
• Inventors: ROCHLITZ, WALKER L., SHIM, ANNE KATJA, SUHR, LINDSEY M., TABLER, RAYMOND LEE, TASCARELLA, DAVID SHAWN, BARNES, KATHLEEN
• Application Number:
  US12/113,395
• Publication Number:
  US 20080242744A1
• Time in Patent Office: Days
• US Class Current: 516/55
• CPC Class Codes: A61K 2800/48 Thickener, Thickening system
• CPC Class Codes: A61K 8/06 Emulsions
• CPC Class Codes: A61K 8/585 Organosilicon compounds
• CPC Class Codes: A61K 8/86 Polyethers
• CPC Class Codes: A61K 8/891 saturated, e.g. dimethicone, phenyl trimethicone, C24-C28 methicone or stearyl dimethicone
• CPC Class Codes: C08G 77/20 containing silicon bound to unsaturated aliphatic groups C08G77/045 takes precedence
• CPC Class Codes: C08J 2383/04 Polysiloxanes
• CPC Class Codes: C08J 3/05 from solid polymers
• CPC Class Codes: C09K 23/54 Silicon compounds

Abstract

A process is disclosed for making a silicone-in-water emulsion by forming a hydrophobic phase containing a silicone component, mixing one or more surfactants with the hydrophobic phase, adding water to the hydrophobic phase and shear mixing in a twin-screw extruder to form a silicone in water emulsion.

Claims

1. A method of making a silicone-in-water emulsion comprising the steps of:

(i) forming a hydrophobic phase containing a silicone component selected from a silicone fluid, silicone gum, a silicone rubber, a silicone elastomer, a silicone resin, or a mixture thereof;

the silicone in the hydrophobic phase having a viscosity of at least 1,000 mm²/s to 5,000,000,000 mm²/s at 23°

C.;

(ii) mixing one or more surfactants with the hydrophobic phase;

(iii) adding water to the hydrophobic phase, the water being added in an amount of 0.5-10 percent by weight based on the weight of the hydrophobic phase;

(iv) shearing the mixture in a twin-screw extruder having a length to diameter (L/D) ratio of at least 12 to form a silicone-in-water emulsion; and

(v) optionally, diluting the silicone-in-water emulsion by the addition of water;

the method being carried out in the absence of a solvent other than solvents present in the silicone fluid, silicone gum, silicone rubber, silicone elastomer, or silicone resin in (i).

2. The method of claim 1 wherein the silicone component is a polydimethylsiloxane fluid.

3. The method of claim 1 wherein the silicone component is a mixture of a polydimethylsiloxane fluid and a silicone gum.

4. The method of claim 1 wherein the silicone component contains an aminofunctional siloxane.

5. The method of claim 1 wherein the surfactant is a polyoxyethylene fatty alcohol or a mixture of polyoxyethylene fatty alcohols.

6. The method of claim 1 wherein the twin-screw extruder has an L/D ratio of 12-60.