| abstract |
The present invention provides a rubber composition having excellent low heat build-up, fracture strength and crack growth resistance, and a pneumatic tire having a base tread, cushion, case or tie gum made using the rubber composition. (A) The following formula (1); (Wherein R 1 , R 2 and R 3 represent an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group, a mercapto group or a derivative thereof. R 4 and R 5 are a hydrogen atom or an alkyl group. N represents an integer.) Is polymerized with a butadiene rubber modified with a compound represented by the following formula: and / or a lithium initiator, and the content of tin atoms, the amount of vinyl bonds, and the molecular weight distribution are in a specific range value. 10 to 30% by mass of tin-modified polybutadiene rubber, (b) 10 to 40% by mass of modified SBR having a bound styrene content of 21% by mass or less, and 20 to 20c of diene rubbers other than (c) (a) and (b) The present invention relates to a rubber composition containing a rubber component containing -80% by mass. [Selection figure] None |