A process for preparing polypropylene-b-poly(ethylene-co-propylene) by the use of a tubular continuous polymerizer in the presence of an olefin-polymerizing catalyst comprising a solid catalyst component (1) composed of titanium and halogen; an organosilicon compound (2); and, if necessary, at least one electron-donating compound (3) selected from the group consisting of organosilicon compounds represented by the general formula: RnSi(OR')4-n (wherein R and R' are each independently a C1-C10 hydrocarbon group; and n is an integer of 1 to 3) and nitrogenous heterocyclic compounds, wherein the solid catalyst component (1) is preliminarily brought into contact with the organosilicon compound (2) in the presence of the electron-donating compound (3), and then a polypropylene segment is formed through polymerization, followed by formation of a poly(ethylene-co-propylene) segment at the end of the polypropylene segment through polymerization. The process enables efficient preparation of the polymer with a reduced content of inorganic contaminants, even when the polymer is one having a weight-average molecular weight of as high as 100,000 or more.
一种在烯烃聚合催化剂存在下使用管式连续聚合器制备聚
丙烯-b-聚(
乙烯-共
丙烯)的工艺,烯烃聚合催化剂包括由
钛和卤素组成的固体催化剂组分(1);
有机硅化合物(2);以及必要时至少一种电子供体化合物(3),该化合物选自由通式如下的
有机硅化合物组成的组:RnSi(OR')4-n(其中 R 和 R'各自独立地为 C1-C10 烃基;n 为 1 至 3 的整数)和含氮
杂环化合物,其中固体催化剂组分(1)在电子赋 予化合物(3)的存在下与
有机硅化合物(2)初步接触,然后通过聚合形成聚
丙烯段,接着通过聚合在聚
丙烯段的末端形成聚(
乙烯-共
丙烯)段。即使聚合物的重量平均分子量高达 100,000 或更高,该工艺也能高效制备出无机污染物含量较低的聚合物。