Crosslinkable rubber composition and use thereof

The crosslinkable rubber composition is crosslinkable at room temperature, has a gelation time at room temperature of 30 days or less, and can prepare a crosslinked rubber sheet by crosslinking the composition at room temperature, wherein the crosslinked rubber sheet has a tensile elongation of 20% or more, and is free of cracks after treatment at 40° C. in a 50 pphm ozone concentration for 96 hr. Specifically, it comprises an ethylene/alpha-olefin/non-conjugated polyene random copolymer rubber comprising a norbornene compound having a specific vinyl end group, an SiH group-containing compound, which has at least two SiH groups in one molecule, and optionally a platinum catalyst, a reaction inhibitor and/or a silane-coupling agent. The sealing, potting and coating materials and adhesives of the present invention comprise the above rubber composition. The rubber composition has a high crosslinking rate at room temperature and excellent productivity, and can prepare crosslinked rubber molded products (including foamed products) having excellent weathering resistance, ozone resistance, heat aging resistance and compression set at low cost. Further, it is suitable for use of electric and electronic parts, transportation machines, civil engineering and construction materials, medical appliances and goods for leisure activities.