To obtain a rubber composition having extremely low hysteresis loss and satisfiably balanced breaking characteristics, abrasion resistance, etc., by modifying a conjugated diene (co)polymer with a specific silane modifying agent and mixing with silica.
The objective rubber composition is produced by polymerizing a conjugated diene monomer (preferably 1,3-butadiene or isoprene) or a conjugated diene monomer and a vinyl aromatic hydrocarbon monomer (preferably styrene) in the presence of an organic lithium-based initiator (e.g. n-butyllinium), modifying the polymerization activity terminal of the obtained (co)polymer with a modifying agent reactive with silica surface and expressed by the formula (R1 is a substituent having epoxy or an unsaturated carbonyl group; X is an alkyl or a halogen; R2 is a 1-20C aliphatic, alicyclic or aromatic hydrocarbon group; (m) and (n) are each 1-3; m+n is 2-4) (preferably γ-glycidoxypropyl trimethoxysilane) and finally mixing the obtained terminal-modified (co)polymer with a silica (preferably silica prepared by wet-process) in an organic solvent.
SHIMIZU TAKASHI
KITAMURA TAKASHI
