| abstract |
A silicone elastomeric emulsion having improved shelf life is produced by a method which mixes the ingredients of the emulsion with the exception of a filler other than colloidal silica, then ages the mixture for at least two weeks at room temperature then adds the filler other than colloidal silica. The improved emulsion yields a film upon drying that has better physical properties. The emulsion contains an anionically stabilized, hydroxyl endblocked polydiorganosiloxane, colloidal silica, and an alkyl tin salt, as well as the filler other than colloidal silica. The emulsion has a pH of greater than 9 and a solids content of greater than 40 percent by weight. The emulsion is useful in forming a protective elastomeric coating over a substrate and as a caulking material. |