Conjugated diolefin-based copolymer rubber of a conjugated diolefin and an aromatic vinyl compound, wherein
(1) the content of amino groups bound to the rubber (nitrogen content value) is 0.0025 to 0.20 mmol/g of copolymer rubber,
(2) the content of the polymerization units of the aromatic vinyl compound is 5 wt% or more and less than 30 wt% based on the copolymer rubber, and the content of vinyl bonds in the polymerization unit of the conjugated diolefin (the total content of a 1,2-bond and a 3,4-bond) is 55 mol% or more based on the polymerization unit of the conjugated diolefin, or the content of the polymerization units of the aromatic vinyl compound is 30 to 50 wt% based on the copolymer rubber and the content of vinyl bonds in the polymerization unit of the conjugated diolefin is 25 to 55 mol% on the polymerization unit of the conjugated diolefin and
(3) the molecular weight distribution is polymodal.
共轭二烯烃和芳香族
乙烯基化合物的共轭二烯烃基共聚橡胶,其中
(1) 与橡胶结合的
氨基含量(氮含量值)为 0.0025 至 0.20 毫摩尔/克共聚橡胶、
(2) 芳香族
乙烯基化合物聚合单元的含量为共聚物橡胶的 5 wt%或以上且小于 30 wt%,共轭二烯烃聚合单元中
乙烯基键的含量(1,2 键和 3,4 键的总含量)为共轭二烯烃聚合单元的 55 mol%或以上、或芳香族
乙烯基化合物聚合单元的含量为共聚橡胶的 30 至 50 wt%,共轭二烯烃聚合单元中
乙烯基键的含量为共轭二烯烃聚合单元的 25 至 55 mol%,以及
(3) 分子量分布呈多模态。