Metallocene catalysts esp. used for prepn. of high mol. mass polypropylene@ - comprise silyl substd., di:yl bridged cpds., and at least one cyclopentadienyl gp. capable of forming sandwich structure

摘要

Metallocenes of formula (I) are new (where A = silyl gps. of formula -Si(Q)(S)(T) (1) ; B = A or X1; L1, L2 = opt. mono- or polysubstd. hydrocarbon contg. at least one ring and at least one cyclopentadienyl gp., capable of forming a sandwich structure with M, or L1 is an opt. mono- or polysubstd. hydrocarbon contg. at least one cyclopentadienyl gp. forming a sandwich structure with M and L2 is an amido, phosphido or arsenido gp. of formula E-D (2) ; M = Ti, Zr, Hf, V, Nb, Ta or lanthanide gp. element ; Q - T = X1 or silyl ; R = C, Si, Ge or Sn ; X1, X2 = 1-10C alkyl, 1-10C alkoxy, 6-10C aryl(oxy), 2-10C alkenyl, 7-20C arylalkyl, 7-20C alkylaryl, 8-20C arylalkenyl, H or halogen. Also claimed are (i) the prepn. of (I) by reacting cpds. of formula [L1R(A)(B)L2](M1)2 (II) with cpds. M(X')2X1X2 (III) and (ii) the prepn. of polyolefins by polymerisation of olefins using (I) as catalysts; In formulae, M1 = alkali metal ; and X' = halogen. Pref. A and/or B are trialkylsilyl and L1 and/or L2 are opt. substd. cyclopentadienyl, indenyl or fluorenyl. Aluminoxanes are used as co-catalysts for the prepn. of polyolefins.