Patent ID: 6995210

Claim:
A process for the preparation of an aqueous dispersion of silicone oil(s) comprising: 100 parts by weight of at least one polyorganosiloxane oil (A) capable of crosslinking into an elastomer by condensation, if necessary in the presence of a crosslinking agent (B); optionally, from 0.1 to 100 parts by weight of at least one crosslinking agent (B); optionally, up to 50 parts by weight of at least one adhesion promoter (C); greater than 0 up to 200 parts by dry weight of a filler (D); a catalytically effective amount of a catalytic curing compound (E); at least one emulsifier (F); optionally, at least one functional additive (G); and water; said process comprising the steps of: preparing an emulsion by blending a mixture consisting of: 100 parts by weight of a silicone phase (φs) with a dynamic viscosity at 25° C. of at least 10 Pa.s, φs comprising the oil or a mixture of oils (A) already polymerized, and optionally at least one of the constituents (B), (C) or (E); 0.5–20 parts by weight of at least one emulsifier (F), the HLB value of said emulsifier or of the mixture of emulsifiers being at least 10; the filler (D); 2–20 parts by weight of water; with a water/water and surfactant(s) weight ratio being such that the water and the surfactant(s) makes a mixture having a viscosity in the region of or greater than half that of the silicone phase (φs); for a period and under shear conditions that are sufficient to obtain an “oil-in-water” emulsion with a particle size from about 0.1 to 5 micrometers; optionally, diluting with water until a solids content from 25% to 97% is obtained; and, then, adding the constituent(s) not present in the silicone phase (φs) and the filler (D); the filler (D) being supplied in the form of (an) aqueous suspension(s) of at least one hydrophilic compound, with the proviso that: when the filler (D) is at least partly in the form of at least one aqueous suspension of colloidal silica, then this (or these) aqueous suspension(s) of filler (D) is (are) introduced into a blending chamber before producing the emulsion; or when the filler (D) is at least partly in the form of at least one aqueous suspension of organic (co)polymer(s), then at least some of this (or these) aqueous suspension(s) of filler (D) is (are) introduced into a blending chamber before producing the emulsion, said dispersion further comprising a filler (D′), which is added in the process for obtaining the dispersion, in pulverulent form, and whose specific surface area Ss (in m 2 /g) is: Ss≦5.