DIEN-KOPOLYMER WITH MODIFIED END GROUPS AND RUBBER COMPOSITION FOR TIRE FLOOR

摘要

The present invention relates to an end-modified diene copolymer and a rubber composition for tire tread containing the same. More particularly, the present invention relates to a polymer and a rubber composition for tire tread comprising a mixture of the polymer with a vulcanizing agent and an inorganic filler such as carbon black and silica, the polymer being prepared by reacting the active end of a conjugate diene polymer, or a copolymer comprising at least one conjugate diene compound and a vinyl-substituted aromatic compound, polymerization-initiated using an organic lithium catalyst, with a coupling agent represented by the formula 1, Y-äC(R3)(R4)üc-CH2CH2-Si(R1)(R2)-äO-Si(R1)(R2)üd-CH2CH2-äC (R3)(R4)üc-Y, in which Y represents (X)a(R)bSi, (X)a(R)bC or (X)e(R1)fBz-X; X represents a halogen atom selected from the group consisting of F, Cl, Br or I; R represents a lower alkyl group containing 1 to 20 carbon atoms, including a methyl group, an ethyl group or a propyl group; R1, R3 and R4 are same or different from one another and are selected from a hydrogen atom, a lower alkyl group 1 to 20 carbon atoms, a halogen-substituted alkyl group, or a halogen-substituted silane group; R2 is the same as X or R1, or represents (X)g(R3)hC-äC(R3)(R4)üc-1; a is 1 to 3; b is 0 to 2, wherein a + b = 3; c is 1 to 1,000; d is 1 to 50,000; e and fare independently 0 to 4, wherein e + f= 4; g and h are independently 0 to 3, wherein g + h = 3; and Bz-X represents benzyl halogen. The rubber composition for tire treads comprising the end-modified diene copolymer as an ingredient rubber enhances rolling resistance and wet skid resistance as well as mechanical properties directly concerned to the properties of the tires.