| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rubber composition for tire treads, which keeps abrasion resistance, processability and tear resistance and has an improved low heat-generating property, and to provide a pneumatic tire using the rubber composition in a cap tread rubber portion. <P>SOLUTION: This rubber composition for tire treads includes a rubber component and carbon black, wherein the carbon black satisfies the following (1) to (4): (1) the dibutyl phthalate (DBP) absorption number [unit: mL/100 g] of the carbon black is from 90 to 180; (2) the difference of the BET specific surface area (BET5) [unit: m<SP POS="POST">2</SP>/g] of the carbon black from the external specific surface area (STSA) [unit: m<SP POS="POST">2</SP>/g] thereof satisfies the following: 5≤(BET5)-(STSA)≤12; (3) the ratio between the Stokes diameter (Dst) of the carbon black and the Stokes diameter distribution (ΔD-50 (half band width)) thereof satisfies the following: 0.70≤the ratio of (ΔD-50)/(Dst)≤1.10; and (4) the ratio between the BET specific surface area (BET5) [unit: m<SP POS="POST">2</SP>/g] of the carbon black and the iodine adsorption number (IA) [unit: mg/g] thereof satisfies the following: 1.05≤the ratio of (BET5)/(IA)≤1.35. <P>COPYRIGHT: (C)2012,JPO&INPIT |
