Thermoplastic elastomer compositions of the present invention comprise a blend of from about 10to about 50 parts by weight of a crystalline 1-olefin polymer, from about 80 to about 15 parts by weight of a styrene-butadiene rubber, and from about 5 to about 50 parts by weight of bitumen. The thermoplastic blends have unexpectant increases in properties, especially tear strength, tensile strength, high temperature (100°C) tear strength, and smooth surfaces when injection molded. Moreover, the bitumen lowers the injection molding pressure, thus enabling larger parts to be molded. The compositions, which may be partially cured, also have excellent aging properties. The compositions are a true thermoplastic in that they can be repeatedly processed and yet maintain their good physical properties.
本发明的热塑性弹性体组合物包括按重量计约 10 至约 50 份的结晶 1-烯烃聚合物、按重量计约 80 至约 15 份的
丁苯橡胶和按重量计约 5 至约 50 份的
沥青的混合物。这种热塑性混合物的性能有意想不到的提高,特别是撕裂强度、拉伸强度、高温(100°C)撕裂强度和注塑时的光滑表面。此外,
沥青还能降低注塑压力,从而使更大的部件得以成型。可部分固化的组合物还具有优异的老化性能。这种组合物是一种真正的热塑性塑料,可以反复加工,但仍能保持良好的物理性能。