Patent ID: 7381679

Claim:
Catalyst combination for producing linear isotactic polymers containing (i) an asymmetrical metal complex of the general formula I, wherein R 1 -R 4 are linear or branched C 1 - to C 10 -alkyl, 5- to 7-membered cycloalkyl, optionally substituted with one or more C 1 - to C 6 -alkyl radicals, C 6 - to C 18 -aryl or arylalkyl or alkylaryl, or R 1 /R 2 , R 3 /R 4 being able to be bonded in 5- to 7-membered cycloalkyl or aryl rings; R 6 -R 9 are hydrogen, linear or branched C 1 - to C 10 -alkyl, 5- to 7-membered cycloalkyl, optionally substituted with one or more C 1 - to C 6 -alkyl radicals, C 6 - to C 18 -aryl or arylalkyl or alkylaryl, with the proviso that the radicals R 6 /R 7 or R 8 /R 9 are bonded in 5- to 7-membered anellated cycloalkyl or aryl rings, the latter being optionally substituted, interrupted with heteroatoms and/or combined with a further cycloalkyl and/or aryl ring; R 12 is C 1 - to C 8 -alkyl, aryl, C 1 - to C 8 -oxyalkyl, or C 1 - to C 8 -trialkylsiloxy; M is titanium, zirconium, hafnium, vanadium, niobium, or tantalum; X is hydrogen, halogen, C 1 - to C 8 -alkyl, aryl, or benzyl; E is carbon, silicon, germanium, 1,2-ethylene, 1,3-propylene, or 1,4-butylene, wherein when E is carbon, silicon, or germanium, E is optionally substituted with R 10 and R 11 ; R 10 -R 11 are hydrogen, C 1 - to C 8 -alkyl, 4- to 7-membered cycloalkyl, or aryl, or R 10 , R 11 together with E being able to form a 4- to 7-membered cycloalkyl or aryl; and (ii) an activator.