Silica-containing rubber composition, a manufacturing method thereof, and crosslinked molded article

PROBLEM TO BE SOLVED: To provide a silica-containing rubber composition that is excellent in processability, reinforcing properties and abrasion resistance and is suitably employable as a rubber for a tire, and its manufacturing method, and to provide a crosslinkable silica-containing rubber composition and a crosslinked molded item thereof. SOLUTION: The manufacturing method of the silica-containing rubber composition comprises a step for kneading a conjugated diene rubber-silica co-coagulate with a silane coupling agent, where kneading of the conjugated diene rubber-silica co-coagulate is started at 5-90°C and, after the kneading temperature is reached 120°C or higher, the silane coupling agent is added to the kneadate of the conjugated diene rubber-silica co-coagulate followed by further kneading. The crosslinkable rubber composition is obtained from the silica-containing rubber composition. The crosslinked molded item is also provided. COPYRIGHT: (C)2008,JPO&INPIT