A process for preparing a copolymer by copolymerizing ethylene and at least one other 1-monoolefin and, optionally, and unconjugated diene in the presence of a mixed catalyst of (1) a compound of a metal of main Groups I-III of the periodic table having at least one hydrogen atom or an alkyl or aryl group bound to the metal atom, and (2) a compound of a metal of Subgroups IV-VI of the periodic table, comprises performing the copolymerization in the presence of an amount effective as an activator of a 2, 3,4,4-tetrachloro-2-butenoic acid ester of the fromula HCCl.sub.2 --CCl=CCl--COOR wherein R is an optionally halogenated alkyl, cycloalkyl, aryl, alkaryl or aralkyl group, and wherein the cycloalkyl, aryl, alkaryl or aralkyl groups are optionally substituted by one or more alkyl groups.
一种制备共聚物的方法,通过在混合催化剂的存在下共聚
乙烯和至少一种其他1-单烯烃以及可选的非共轭二烯,所述混合催化剂包括(1)主周期表I-III族
金属化合物,其
金属原子上至少有一个氢原子或烷基或芳基基团,以及(2)副周期表IV-VI族
金属化合物,包括在有效量下作为2,
3,4,4-四
氯-
2-丁烯酸酯的激活剂的共聚反应,所述2,
3,4,4-四
氯-
2-丁烯酸酯的
化学式为HCCl.sub.2 --CCl=CCl--COOR,其中R是可选的卤代烷基,环烷基,芳基,烷基芳基或芳基烷基基团,且所述环烷基,芳基,烷基芳基或芳基烷基基团可选择性地被一个或多个烷基基团取代。