| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rubber composition for a side wall and a pneumatic tire improving an elastic modulus, fatigue resistance and resistance to fracture in good balance without lowering rubber properties of vulcanized rubber, and enabling to reduce rolling resistance by improving low heat buildup. <P>SOLUTION: This rubber composition for a side wall includes 40-70 pts.mass of at least one of natural rubber and polyisoprene rubber, 30-60 pts.mass of polybutadiene rubber when the total amount of rubber components is made 100 pts.mass. The content of an inorganic filler is 0.5-15 pts.mass to 100 pts.mass of the rubber component. The inorganic filler has a repose angle of ≥40°, Mohs hardness of ≤2.0, BET specific surface area (BET5) (m<SP POS="POST">2</SP>/g) of ≥10 m<SP POS="POST">2</SP>/g, and the ratio (DBP)/(BET5) of dibutyl phthalate absorption (DBP) (mL/100g) to BET specific surface area (BET5) (m<SP POS="POST">2</SP>/g) is ≥2.0. <P>COPYRIGHT: (C)2013,JPO&INPIT |
