Abstract: A batch steam distillation process removes volatile siloxane oligomers from an emulsion containing siloxane polymers and volatile siloxane oligomers prepared by emulsion polymerization of volatile siloxane oligomers. In one embodiment, emulsions stripped of volatile siloxane oligomers are re-catalyzed to initiate condensation polymerization. In another embodiment, clear emulsions stripped of volatile siloxane oligomers are provided even though an antifoam is used in the stripping process.

Abstract: A batch steam distillation process removes volatile siloxane oligomers from an emulsion containing siloxane polymers and volatile siloxane oligomers prepared by emulsion polymerization of volatile siloxane oligomers. In one embodiment, emulsions stripped of volatile siloxane oligomers are re-catalyzed to initiate condensation polymerization. In another embodiment, clear emulsions stripped of volatile siloxane oligomers are provided even though an antifoam is used in the stripping process.

Abstract: A batch steam distillation process removes volatile siloxane oligomers from an emulsion containing siloxane polymers and volatile siloxane oligomers prepared by emulsion polymerization of volatile siloxane oligomers. In one embodiment, emulsions stripped of volatile siloxane oligomers are re-catalyzed to initiate condensation polymerization. In another embodiment, clear emulsions stripped of volatile siloxane oligomers are provided even though an antifoam is used in the stripping process.

Abstract: Emulsions and latexes containing polymer particles with a diameter greater than 0.02 micron are prepared by (i) forming a microemulsion containing particles of oligomers with a diameter less than 0.02 micron by combining water, a surfactant, a hydride functional organosilicon oligomer or a mixture of such oligomers, and an alkenyl functional organosilicon oligomer or a mixture of such oligomers; (ii) adding a catalyst to the microemulsion; (iii) initiating polymerization of the oligomers; and (iv) continuing polymerization until an emulsion or latex is formed containing polymer particles with a diameter greater than 0.02 micron.

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.

Abstract: Emulsions and microemulsions containing particles of siloxane polymers are prepared by an emulsion polymerization process involving (i) the formation of a mixture by combining a siloxane oligomer, an ionic surfactant, no nonionic surfactant, and water; (ii) agitating the mixture without using high shearing forces (homogenization) to form droplets of oligomer prior to polymerization that have an average diameter of greater than 10 micron/10,000 nanometer; (iii) adding a siloxane polymerization catalyst to the oligomer mixture; (iv) agitating the mixture without using high shearing forces; (v) polymerizing the oligomer to form new particles of polymer; and (vi) continuing step (v) until the polymer has increased in viscosity or molecular weight.

Abstract: Volatile siloxane oligomers are removed from an emulsion containing siloxane polymers and volatile siloxane oligomers prepared by emulsion polymerization of volatile siloxane oligomers by continuously feeding the emulsion to a continuous flow device for vaporizing liquids, continuously feeding a stripping gas to the continuous flow device, continuously removing an overhead fraction of volatile siloxane oligomers from the continuous flow device, and continuously removing an unvaporized bottom fraction from the continuous flow device of an emulsion containing siloxane polymers which is substantially free of residual volatile siloxane oligomers used to prepare the emulsion. A benefit of the method is that the viscosity of the siloxane polymer in the emulsion before the emulsion is fed to the continuous flow device is substantially the same as the viscosity of the siloxane polymer in the emulsion after the emulsion is removed from the continuous flow device.

Abstract: Emulsions and latexes containing polymer particles with a diameter greater than 0.02 micron are prepared by (i) forming a microemulsion containing particles of oligomers with a diameter less than 0.02 micron by combining water, a surfactant, a hydride functional organosilicon oligomer or a mixture of such oligomers, and an alkenyl functional organosilicon oligomer or a mixture of such oligomers; (ii) adding a catalyst to the microemulsion; (iii) initiating polymerization of the oligomers; and (iv) continuing polymerization until an emulsion or latex is formed containing polymer particles with a diameter greater than 0.02 micron.

Abstract: Dialkyl sulfonic acid catalysts such as dialkyl benzene sulfonic acids, dialkyl naphthalene sulfonic acids, salts of dialkyl benzene sulfonic acids, and salts of dialkyl naphthalene sulfonic acids, are used to prepare emulsions containing particles of organopolysiloxanes having an average particle diameter in the emulsion of at least one micron (&mgr;m) A silanol endblocked siloxane is used as an oligomer and has the structure wherein R1 to R6 are alkyl or aryl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and phenyl; and n has a value such as to provide oligomers with a viscosity ranging from about 20 to about 100,000 centipoise (mPa·s). The emulsified oligomer is then polymerized with the catalyst to form an organopolysiloxane polymer having a viscosity which can be as high as about 10 million centipoise (mPa·s).

Abstract: The viscosity of a solvent is modified by thickening the solvent with a silicone latex. A silicone latex having a plurality of crosslinked polysiloxane particles is first prepared by mixing the siloxane polymer, a surfactant, and water; emulsifying the mixture to a gel phase; diluting the emulsion with water; adding a cure package (i.e., a catalyst, a crosslinker, or both, or a self catalytic crosslinker); and then without removing the water from the latex and after the particles of siloxane polymer in the latex have been cured, mixing the latex and solvent to thicken the solvent, forming viscous liquids, gels, and pastes. Water in the latex thickened solvent composition can be stabilized by adding a silicone polyether during mixing of the latex and the solvent.

Abstract: Described is a method of preparing microemulsions of organopolysiloxanes, by copolymerizing a cyclic siloxane and a polyfunctional silane, in an aqueous medium containing a nonionic surfactant, an anionic or cationic surfactant, and a catalyst, until the desired increase in molecular weight is obtained. The invention resides in controlling the gel content of the organopolysiloxanes in the microemulsion by control of the concentration of silane and concentration of silanol in the resulting organopolysiloxane, such that a functionality ratio .phi. results in formation of a gel-free polymer molecular weight distribution of finite organopolysiloxane species in the microemulsion.

Abstract: Described is a method of preparing microemulsions of organopolysiloxanes, by copolymerizing a cyclic siloxane and a polyfunctional silane, in an aqueous medium containing a nonionic surfactant, an anionic or cationic surfactant, and a catalyst, until the desired increase in molecular weight is obtained. The invention resides in controlling the gel content of the organopolysiloxanes in the microemulsion by control of the concentration of silane and concentration of silanol in the resulting organopolysiloxane, such that a functionality ratio .phi. results in formation of a gel-free polymer molecular weight distribution of finite organopolysiloxane species in the microemulsion.