Catalyst system

Abstract

A catalyst system comprises a) a cocatalytically active chemical compound A, b) at least one metallocene B and c) an aluminum compound C.

We claim:  
     
         1 . A catalyst system comprising a) at least one cocatalytically active chemical compound A, b) at least one metallocene B and c) at least one aluminum compound C, wherein the chemical compound A is an organoboron-aluminum compound comprising units of the formula I  
       
         
           
           
               
               
           
         
         where R 1  are identical or different and are each a hydrogen atom, a halogen atom, a C 1 -C 40 -group such as C 1 -C 20 -alkyl, C 1 -C 20 -haloalkyl, C 1 -C 10 -alkoxy, C 6 -C 20 -aryl, C 6 -C 20 -haloaryl, C 6 -C 20 -aryloxy, C 7 -C 40 -arylalkyl, C 7 -C 40 -haloarylalkyl, C 7 -C 40 -alkylaryl or C 7 -C 40 -haloalkylaryl or R 1 can be an OSiR 3   3  group, where R 3  are identical or different and are each a hydrogen atom, a halogen atom, a C 1 -C 40 -group such as C 1 -C 20 -alkyl, C 1 -C 20 -haloalkyl, C 1 -C 10 -alkoxy, C 6 -C 20 -aryl, C 6 -C 20 -haloaryl, C 6 -C 20 -aryloxy, C 7 -C 40 -arylalkyl, C 7 -C 40 -haloarylalkyl, C 7 -C 40 -alkylaryl or C 7 -C 40 -haloalkylaryl,  
         R 2  is a halogen atom, C 1 -C 20 -haloalkyl, C 6 -C 20 -haloaryl, C 7 -C 40 -haloarylalkyl or C 7 -C 40 -haloalkylaryl or R 2  can be an OSiR 3   3  group, where R 3  are identical or different and are each a halogen atom, C 1 -C 20 -haloalkyl, C 1 -C 10 -haloalkoxy, C 6 -C 20 -haloaryl, C 6 -C 20 -haloaryloxy, C 7 -C 40 -haloarylalkyl or C 7 -C 40 -haloalkylaryl,  
         i is 0, 1 or 2, and  
         j is 0 or 1.  
       
     
     
         2 . A catalyst system as claimed in  claim 1  which further comprises a support.  
     
     
         3 . A process for preparing a polefin by polymerization of one or more olefins in the presence of a catalyst system as claimed in  claim 1  or  2 .  
     
     
         4 . The use of a catalyst system as claimed in  claim 1  or  2  for preparing a polyolefin.