Cement mold-making silicone rubber composition
A cement mold-making silicone rubber composition is provided comprising (A) 100 parts by weight of a polyorganosiloxane having at least two silicon-bonded monovalent aliphatic unsaturated hydrocarbon groups in a molecule, (B) a polyorganohydrogensiloxane having at least three silicon-bonded hydrogen atoms in a molecule, in such an amount as to provide 0.1-5 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 1-100 ppm of platinum atoms based on the weight of component (A), (D) 5-60 parts by weight of finely divided silica having a specific surface area of at least 50 m 2 /g, and (E) 0.1-100 parts by weight of coal ash and/or pozzolan powder.
1. 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.
2. A method of molding a cement material comprising casting the cement material into the cement mold of claim 1 .
3. 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) 5 to 30 parts by weight of coal ash and/or pozzolan powder.
4. A cement mold formed by extruding a silicone rubber composition onto a master pattern so as to enclose the 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) 5 to 30 parts by weight of coal ash and/or pozzolan powder.
5. A method of molding a cement material comprising casting the cement material into the cement mold of claim 3 .
6. A method of molding a cement material comprising casting the cement material into the cement mold of claim 4 .