Patent ID: 8044121

Claim:
A cement mold formed by casting or coating a silicone rubber composition onto a surface portion of a master pattern and removing the mold from the master pattern, said silicone rubber composition comprising (A) 100 parts by weight of a polyorganosiloxane having at least two monovalent aliphatic unsaturated hydrocarbon groups each bonded to a silicon atom in a molecule, (B) a polyorganohydrogensiloxane having at least three hydrogen atoms each bonded to a silicon atom in a molecule, in such an amount as to provide 0.1 to 5 silicon-bonded hydrogen atoms per monovalent aliphatic unsaturated hydrocarbon group in component (A), (C) a platinum base compound in such an amount as to provide 1 to 100 ppm of platinum atoms based on the weight of component (A), (D) 5 to 60 parts by weight of finely divided silica having a specific surface area of at least 50 m 2 /g, and (E) 0.1 to 100 parts by weight of coal ash and/or pozzolan powder.