Patent ID: 8614272

Claim:
A tire rubber composition comprising: a rubber component including a diene polymer; silica; and a silane coupling agent represented by the following formula (4); and/or a silane coupling agent that is a copolymer comprising units A represented by the following formula (5) and units B represented by the following formula (6), wherein the proportion of the units B is 1 to 70 mol % of the total molar amount of the units A and the units B: wherein R 8 represents a group represented by the formula: —O—(R 12 —O)m—R13, m R 12 s may be the same as or different from each other and each represents a branched or unbranched C 1-30 divalent hydrocarbon group, R 13 represents a branched or unbranched C 1-30 alkyl group, a branched or unbranched C 2-30 alkenyl group, a C 6-30 aryl group, or a C 7-30 aralkyl group, and m is an integer of 1 to 30; R 9 and R 10 are the same as or different from each other and each represents the same group as R 8 , or a branched or unbranched C 1-12 alkyl group or a group represented by the formula —O—R 14 , and R 14 represents a hydrogen atom, a branched or unbranched C 1-30 alkyl group, a branched or unbranched C 2-30 alkenyl group, a C 6-30 aryl group, or a C 7-30 aralkyl group; and R 11 represents a branched or unbranched C 1-30 alkylene group, wherein x and y each represent an integer of 1 or larger; R 15 represents hydrogen, a halogen, or a branched or unbranched C 1-30 alkyl or alkylene group, a branched or unbranched C 2-30 alkenyl or alkenylene group, a branched or unbranched C 2-30 alkynyl or alkynylene group, or a group obtained by replacing the end of the alkyl or alkenyl group with a hydroxy or carboxyl group; R 16 represents hydrogen, a branched or unbranched C 1-30 alkylene or alkyl group, a branched or unbranched C 2-30 alkenylene or alkenyl group, or a branched or unbranched C 2-30 alkynylene or alkynyl group; and R 15 and R 16 may form a ring together, the diene polymer being a modified diene polymer obtained by reacting a compound (A) and a compound (B), the compound (A) being an active alkali metal-terminated conjugated diene polymer obtained by polymerizing a conjugated diene monomer alone or with an aromatic vinyl monomer, in the presence of a compound (C), the compound (B) being a modifying agent having a functional group, and the compound (C) being a chemical species obtained by reacting an organic alkali metal compound with a compound represented by the following formula (1): wherein R 1 and R 2 are the same as or different from each other and each represents a hydrogen atom, a branched or unbranched alkyl group, an aryl group, a branched or unbranched alkoxy group, a branched or unbranched silyloxy group, a branched or unbranched acetal group, a carboxyl group, a mercapto group, or a derivative thereof; and A represents a branched or unbranched alkylene group, an arylene group, or a derivative thereof.