Provided is a rubber composition that contains a rubber component having excellent cold flow resistance and has improved low loss property and wear resistance as compared to conventional ones. The rubber composition comprises: a modified conjugated diene-based polymer having a hydroxyl group at a terminal; and at least one of a natural rubber or a polyisoprene rubber. The modified conjugated diene-based polymer preferably has a cis-1,4 bond content of 95% or more; the modified conjugated diene-based polymer preferably has a molecular weight distribution (Mw/Mn) of 2.5 or less; and a content of the modified conjugated diene-based polymer in a rubber component is preferable to be 20 mass% or more.
本发明提供了一种橡胶组合物,其中包含的橡胶成分具有优异的耐冷流性,与传统橡胶相比,低损耗性能和耐磨性也得到了改善。该橡胶组合物包括:末端带有羟基的改性共轭二烯基聚合物;
天然橡胶或聚
异戊二烯橡胶中的至少一种。改性共轭二烯基聚合物的顺式-1,4 键含量最好在 95% 或以上;改性共轭二烯基聚合物的分子量分布(Mw/Mn)最好在 2.5 或以下;橡胶成分中改性共轭二烯基聚合物的含量最好在 20 质量%或以上。