| 摘要 |
PROBLEM TO BE SOLVED: To provide a rubber composition which has tanδof improved temperature dependency, is excellent is abrasion resistance, tensile strength and elongation at break, and is suitably applicable, for example, to a tire tread use. SOLUTION: (A) 40-120 pts. of a SBR-CB rubber composition comprising SBR and carbon black (CB) having N2 SA (N2 specific surface area) of >=70 m<2> /g and (B) 40-120 pts. of a NR-CB rubber composition comprising NR and CB having N2 SA of >=70 m<2> /g, are added and mixed with (C) a material rubber of BR and/or SBR having Tg higher than that of SBR contained in the SBR-CB rubber composition (A) by >=10 deg.C, by an amount to obtain the rubber composition containing <=80 pts. of a total softener amount based on 100 pts. of the total rubber amount. In the rubber composition, the ratio of FMB which is an average CB concentration in relation to the rubber amount in the CB-containing rubber compositions (A) and (B), to FCOM which is a CB concentration in relation to the rubber amount in the rubber composition obtained by mixing using an internal mixer, is 1.2-3.0.
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