The invention provides a process for preparing a cycloolefin random copolymer comprising repeating units derived from (i) ethylene in an amount of 40 to 97% by mole, repeating units derived from (ii) a specified cycloolefin in an amount of 3 to 60% by mol and optionally repeating units derived from (iii) an α-olefin of 3 - 20 carbon atoms in an amount of 0 to 20% by mol, wherein (i) ethylene, (ii) the cycloolefin and optionally (iii) the α-olefin are copolymerized in a liquid phase in the presence of a catalyst formed from (A) a soluble vanadium compound having a tertiary alkoxy group or β-diketone as a ligand and (B) an organoaluminum compound represented by the formula (i-Bu)nAlCl3-n wherein n is 1.0 to 2.5.
本发明提供了一种制备环烯烃无规共聚物的工艺,该共聚物包含来自(i)
乙烯的重复单元(以摩尔计,含量为40-97%),来自(ii)特定环烯烃的重复单元(以摩尔计,含量为3-60%),以及可选地来自(iii)3-20个碳原子的α-烯烃的重复单元(以摩尔计,含量为0-20%)、其中(i)
乙烯、(ii)环烯烃和任选的(iii)α-烯烃在液相中在催化剂存在下共聚,催化剂由(A)具有叔烷氧基或
β-二酮作为配位体的可溶性
钒化合物和(B)由式(i-Bu)nAlCl3-n表示的
有机铝化合物组成,其中n为1.0至2.