Abstract: This invention relates to sprayable aqueous silicone emulsions which form silicone elastomers upon the removal of water having improved smoke and fire resistant properties. The aqueous silicone emulsion comprises water, a product of a diorganosiloxane polymer and a crosslinker, a surfactant and a filler selected from the group consisting of aluminum trihydrate, fumed titanium dioxide, magnesium oxide, ceramic fillers and zinc borate. The silicone emulsion has a viscosity of 10,000 to 120,000 mPa s and exhibits pseudo plastic rheology which facilitates its application by spraying. A softening agent may also be added for modulus control.

Abstract: This invention relates to a method of sealing openings in structural components of a building to reduce the amount of smoke which may pass through the opening in the event of a fire. The method comprises filling an opening in a structural component of a building with a support material; applying a coating of a silicone composition over the filled opening and allowing the silicone composition to cure into a continuous elastomeric film having certain properties. These silicone compositions exhibit pseudo plastic rheology which facilitates their application by spraying.