Clear silicone waterbased elastomers.

摘要

Aqueous silicone emulsions which dry to a clear elastomer comprise emulsions which contain 100 parts by weight of crosslinked polydiorganosiloxane in the form of a dispersed phase with less than 10 percent of the dispersed phase particles having a particle size greater than 1000 nanometers and from 0.7 to 2.0 parts of a surfactant of the formula RSO<8>M, where R is a hydrocarbon radical of from 6 to 20 carbon atoms and M is selected from the group consisting of alkali metal cations and ammonium derivatives. A preferred method of crosslinking is by the use of an alkoxysilane and tin catalyst. The emulsion can be reinforced by addition of colloidal silica dispersions, fumed silica and precipitated silica, in which the silica particles have an average particle diameter of less than 60 nanometers, to give compositions useful as coatings and sealants.