Novel asymmetric ethylene-bridged metallocenes useful as catalysts in the polymerization of olefins and process for preparing said metallocenes
申请人:SOLVAY POLYOLEFINS EUROPE - BELGIUM (Société Anonyme)
公开号:EP0962462A2
公开(公告)日:1999-12-08
Novel asymmetric ethylene-bridged metallocenes useful as catalysts in the polymerization of olefins and process for preparing said metallocenes.
The novel metallocenes are represented by the general formula :
wherein M represents a transition metal selected from titanium, zirconium and hafnium and X and X' represent a halogen atom. Preferably, the transition metal is Zr and the halogen atoms are both chlorine.
Process for producing the novel metallocenes of general formula (I) comprising the steps of:
a) reacting fluorenyllithium with 1,2-dibromoethane to produce 1-(9-fluorenyl)-2-bromoethane,
b) reacting the said 1-(9-fluorenyl)-2-bromoethane with 2,4,7-trimethylindenyllithium to produce 1-(9-fluorenyl)-2-[1-(2,4,7-trimethyl) indenyl] ethane precursor,
c) reacting the said 1-(9-fluorenyl)-2-[1-(2,4,7-trimethyl)indenyl] ethane precursor with butyllithium to produce its dilithium salt and
d) reacting the said dilithium salt with a transition metal halide selected from halides of Ti, Zr and Hf to produce the metallocenes.
The novel metallocenes are useful as catalysts for the polymerization of olefins such as ethylene and propylene and, in particular, for the production of higly isotactic polypropylene.
可用作烯烃聚合催化剂的新型不对称乙烯桥联茂金属以及制备上述茂金属的工艺。
新型茂金属由通式表示:
其中 M 代表选自钛、锆和铪的过渡金属,X 和 X' 代表卤素原子。过渡金属最好是锆,卤素原子最好都是氯。
生产通式(I)的新型茂金属的工艺,包括以下步骤: 1:
a) 使芴基锂与 1,2-二溴乙烷反应,生成 1-(9-芴基)-2-溴乙烷、
b) 将上述 1-(9-芴基)-2-溴乙烷与 2,4,7-三甲基茚基锂反应,生成 1-(9-芴基)-2-[1-(2,4,7-三甲基)茚基]乙烷前体、
c) 将所述 1-(9-芴基)-2-[1-(2,4,7-三甲基)茚基]乙烷前体与丁基锂反应,生成其二锂盐,以及
d) 将上述二锂盐与选自 Ti、Zr 和 Hf 卤化物的过渡金属卤化物反应,生成茂金属。
新型茂金属可用作乙烯和丙烯等烯烃聚合的催化剂,特别是用于生产高异构聚丙烯。