TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Properties: The baked talc has average particle diameter of 2-15 mu m. The surface-modified sedimented silica has Brunauer Emmett Teller specific surface area of 30-80 m2/g, particle diameter of 1-4 mu m (measured by Coulter-counter method) and surface-modification processing degree (M) of 50 or more. The carbon black (D) has iodine absorption amount of 80 mg/g or less, average particle diameter of 250 nm or less and dibutyl phthalate adsorption amount of 10-300 cm3/100 g. Preferred Compounds: The silicon hydride group-containing compound (E) has 2 silicon hydride groups in a molecule, and is of formula: H-Si(-R3)2-(O-Si(-R3)2)a-R4-(Si(-R3)2-O)b-Si(-R3)2-H (II).R3=1-10C monovalent group, or (un)substituted saturated unit having H or aromatic hydrocarbon;a,b=0-20;andR4=1-30C bivalent organic group or oxygen atom.The silicon hydride group-containing compound (F) has 3 silicon hydride groups in a molecule, and is of formula (III).R5=same as R3;c=0-20;andR6=1-30C trivalent organic group.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: The nonconjugated polyene is a norbornene compound of formula (I).n=0-10;R1=H or 1-10C alkyl;andR2=H or 1-5C alkyl.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The rubber composition further contains a surface-modified sedimented silica (C), carbon black (D) and silicon hydride group-containing compounds (E,F). The content of baked talc contained with respect to 100 weight parts of the copolymer (A) is 2-50 weight parts. The total content of baked talc, surface-modified silica and carbon black contained with respect to 100 weight parts of the copolymer (A) is 10-60 weight parts. EXAMPLE - Ethylene propylene-5-vinyl-2-norbornene random copolymer (in weight parts) (100) having intrinsic viscosity of 1100 Pa.second at 25 degrees C, Enstac 24 (RTM: baked talc having average particle diameter of 7 mu m) (15) and E75SS (RTM: surface-modified silica having BET specific surface area of 50 m2/group and average particle diameter of 2.4 mu m) (30) were mixed. Then, platinum-1,3,5,7-tetravinyl methyl cyclosiloxane complex (0.4), silicon hydride group-containing compound (4.5) of formula (IV), silicon hydride group-containing compound (0.5) of formula (V) and 1-ethynyl-1-cyclohexanol (0.1) were added and mixed to obtain rubber composition. A molded product formed using the obtained rubber composition, had excellent sealing property, heat resistance, acid resistance, mechanical characteristics and outgas-proof property.