摘要 |
PROBLEM TO BE SOLVED: To provide a rubber composition capable of giving excellent function on an ice and snow ground and wet properties when used at least on a part contacting with a ground of a tire tread. SOLUTION: The rubber composition comprises a rubber ingredient (A) of at least one of natural rubber and synthetic diene rubbers having a weight average molecular weight of 150,000 or more in terms of polystyrene as measured by gel-permeation chromatography, and a low molecular weight polymer (B) wherein the low molecular polymer (B) has at least one functional group in its molecule and is a copolymer of an aromatic vinyl compound with a conjugated diene compound, in which an amount of the bound aromatic vinyl compound is 5 volume% or less, or a conjugated diene compound polymer, which has a weight average molecular weight of 2,000 to 50,000 in terms of polystyrene as measured by gel-permeation chromatography in the state without stopping modification, wherein bubbles are incorporated in a matrix of the rubber composition. COPYRIGHT: (C)2008,JPO&INPIT |