To obtain a rubber compsn. which is processed or prepared at a high energy efficiency by mixing a specific sulfur-vulcanizable elastomer with particulate precipitated silica having the surface treated with a trialkoxzysilane.
Particulate precipitated silica with a trialkoxysilane dispersed on the surface thereof is obtd. by dissolving 1-20wt.% trialkoxsilane represented by the formula: R1Si(OR2)3 (wherein R1 1-20C alkyl or 6-24C alkyl; and R2 is 1-8C alkyl) in a suspension formed by suspending particulate precipitated silica having a BET specific surface area of 40-600m2/g, a DBP absorption of 10-400, and an average max, particle size of 0.01-0.05μm is an org. solvent (e.g. chloroform or dichlorometane, subjecting the resultant soln. to reaction at 15-150°C for 2min to 10hr, and filtering and drying the reaction product. The treated silica in an amt. of 10-150phr and at least one sulfur-vulcanizable elastomer selected from among conjugated diene (co)polymers and conjugated diene-arom. vinyl compd. copolymers are kneaded together at 140-190°C for 1-20min.
HALASA ADEL FARHAN
ZANZIG DAVID JOHN
