A rubber composition comprises as rubber components (A) 30-95 wt.% of an end-modified styrene-butadiene copolymer and (B) 70-5 wt.% of a diene rubber other than the end-modified styrene-butadiene copolymer (A). The end-modified styrene-butadiene copolymer (A) is obtained by reacting at least one compound to active terminals of a starting styrene-butadiene copolymer containing butadiene moieties, the trans-1,4 bond content of which is 70-95 wt.%, and having a styrene content of 5-60 wt.%. The at least one compound is selected from N-substituted aminoketones, N-substituted thioaminoketones, N-substituted aminoaldehydes, N-substituted thioaminoaldehydes and compounds containing in the molecules thereof an atomic group represented by the following formula:
in which M stands for an oxygen or sulfur atom. The diene rubber (B) has a glass transition temperature higher than -60°C.
一种橡胶组合物由以下橡胶成分组成:(A) 30-95 重量%的末端改性
苯乙烯-
丁二烯共聚物;(B) 70-5 重量%的二烯橡胶(末端改性
苯乙烯-
丁二烯共聚物 (A)除外)。末端改性
苯乙烯-
丁二烯共聚物(A)是通过将至少一种化合物与含有
丁二烯分子(其反式-1,4 键含量为 70-95 重量%,
苯乙烯含量为 5-60 重量%)的起始
苯乙烯-
丁二烯共聚物的活性末端反应而得到的。至少一种化合物选自 N-取代
氨基酮、N-取代
硫代
氨基酮、N-取代
氨基醛、N-取代
硫代
氨基醛和其分子中含有下式所代表的原子团的化合物:
其中 M 代表氧原子或
硫原子。二烯橡胶(B)的
玻璃化温度高于-60℃。