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US 2001/0012872 A1Published application
Emulsion polymerization process
AssigneeGeneral Electric Company
InventorsStephen Dong, Frank J. Traver, James F. Warrenchak
Life of this patent
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Abstract
A method for preparing a silicone emulsion, more particularly a method for preparing a silicone emulsion with a low cyclic siloxane level and particle size control.
Claims16
A process for making a silicone emulsion comprising:
- a) preparing a neutral aqueous surfactant by adding to water an anionic surfactant and a base, and mixing to form a uniform neutral aqueous surfactant having a pH of about 7;
- b) forming a mixture of approximately equal portions of the surfactant and a polysiloxane;
- c) homogenizing the mixture to form an emulsion, wherein the emulsion is homogenized until a desired particle size is achieved;
- d) cooling the homogenized emulsion;
- e) adding an acid to the cooled emulsion and condensing the emulsion to form a polymer, wherein the polymer is condensed until the viscosity reaches the desired level;
- and
- f) neutralizing the condensed emulsion with an effective amount of a neutralizing agent
- wherein the level of cyclic siloxanes in the emulsion is less than one percent by weight.
5 more elements
A silicone emulsion, comprising:
- a) water;
- b) a polysiloxane formed from a low viscosity silanol-stopped siloxane of the formula:
- OH—(R2SiO)x—H
- wherein each R is independently a monovalent hydrocarbon radical;
- and x is an integer, wherein x is chosen such that the viscosity is from about 15 to about 1000 centistokes,
- wherein the polysiloxane has a particle size of from about 0.1 to about 2.0 microns and a polymer viscosity of from about 100,000 to about 6,000,000 centipoise,
- wherein the emulsion contains less than one percent by weight cyclic siloxanes.
4 more elements
Dependencies are inferred from the claim text.