A rubber composition comprises 10 to 70 parts by mass of carbon black having 20 to 100 m2/g of the specific surface area by nitrogen adsorption per 100 parts by mass of a rubber component comprising 20 to 80 parts by mass of a modified polybutadiene rubber and 80 to 20 parts by mass of natural rubber and/or at least one other diene-based synthetic rubber, wherein the modified polybutadiene is obtained by polymerizing 1,3-butadiene in an organic solvent using a compound having a rare earth element of the lanthanoid series, followed by modifying the obtained polybutadiene, and has a content of the cis-1,4-bond of 92% or greater, a content of vinyl bond of 1.5% or smaller and a fraction of the modified chain end of 20% or greater; and a tire using the rubber composition for a sidewall. The rubber composition exhibits excellent low heat buildup property and resistance to fracture.
一种橡胶组合物,包括每 100 份质量的橡胶成分中含有 10 至 70 份质量的
炭黑,其氮吸附比表面积为 20 至 100 m2/g,该橡胶成分包括 20 至 80 份质量的改性聚
丁二烯橡胶和 80 至 20 份质量的
天然橡胶和/或至少一种其他二烯基合成橡胶、其中,改性聚
丁二烯是通过在有机溶剂中使用具有稀土元素的
镧系化合物聚合
1,3-丁二烯,然后对所得到的聚
丁二烯进行改性而得到的,其顺式-1,4-键的含量为 92% 或更高,
乙烯基键的含量为 1.5%或更低,改性链端的比例为 20% 或更高;以及使用该橡胶组合物作为胎侧的轮胎。该橡胶组合物具有优异的低蓄热性能和抗断裂性能。