Modified carbon black, process for producing the modified carbon black, rubber composition and pneumatic tire

摘要

A rubber composition which comprises a rubber component comprising at least one rubber selected from natural rubber and synthetic diene rubbers and, per 100 parts by weight of the rubber component, 30 to 200 parts by weight of a modified carbon black having at a surface thereof an Si-O-C structure or an Si-C structure in which the carbon atom bonded directly to the Si atom is an aromatic carbon atom, and a pneumatic tire prepared by using the rubber composition. The modified carbon black can be obtained by bringing carbon black into contact with a silicon compound, such as a compound represented by a general formula: (R<1>O)mSiR<2>4-m in a gas phase (in the formula, R<1> represents an alkyl group having 1 to 3 carbon atoms, R<2> represents an alkyl group having 1 to 3 carbon atoms or phenyl group and m represents an integer of 2 to 4). The rubber composition exhibits hysteresis loss increased selectively at a high temperature region. The modified carbon black can be advantageously used in the rubber composition. The pneumatic tire in which the rubber composition is used for a tread rubber is advantageously used as a high performance tire exhibiting a remarkably improved gripping property.