| 摘要 |
PROBLEM TO BE SOLVED: To provide a rubber composition capable of reducing a rolling resistance while improving durability such as wear resistance and tear resistance.SOLUTION: A rubber composition includes: a rubber component containing a conjugated diene-based polymer which includes at least one selected from atoms of silicon, tin, sulfur, oxygen and titanium at any of a polymerization active terminal, polymerization initiative terminal or in polymerization chain; a softener having a glass transition point (Tg) of ≤-50°C; and the carbon black for rubber blending, obtained by using a reaction apparatus in which a combustion gas-generating zone, reaction zone and reaction-stopping zone are connectively installed to generate a high-temperature combustion gas in the combustion gas-generating zone, subsequently spray-feeding a raw material into the reaction zone to quickly cool the carbon black-containing reaction gas flow to terminate the reaction. The carbon black for rubber blending satisfies the specific relational expressions (1): 10<X<40 and (2): 90<Z<100 (wherein X is a toluene coloring transmittance (%) of carbon black after introduction of a first quick-cooling medium; and Z is a toluene coloring transmittance (%) of carbon black after introduction of a final quick-cooling medium). |
