Process for the production of highly reactive polyisobutenes

Abstract

The present invention relates to a process for the production of highly reactive polyisobutenes with a content of terminal vinylidene groupings of greater than 80 mol % and an average molecular weight of 500 to 10,000 Dalton by cationic polymerization of isobutene or of isobutene and monomers copolymerizable with isobutene in the presence of solvent-stabilized transition metal complexes with weakly coordinated anions.

What is claimed is:  
     
         1 . A process for the production of highly reactive isobutene homopolymers and copolymers with a content of terminal vinylidene groupings of greater than 80 mol % and an average molecular weight of 500 to 10,000 Dalton, comprising polymerizing an isobutene monomer or an isobutene and a copolymerizable monomer(s) in the presence of a transition metal catalyst of the general formula [M(R 1 -CN) 4-6 ] (A) 2 , wherein 
 M is a metal from the 3rd to 12th periods of the periodic system of elements,    R 1  is a C 1 -C 8  alkyl group and    A is a weakly coordinating anion.    
     
     
         2 . The process according to  claim 1 , wherein the polymerization is performed at a temperature from 0 to 100° C.  
     
     
         3 . The process according to  claim 2 , wherein the polymerization is performed at a temperature from 20 to 60° C.  
     
     
         4 . The process according to  claim 1 , wherein the copolymerizable monomer is isoprene, styrene or a mixture thereof.  
     
     
         5 . The process according to  claim 1 , wherein the polymerization is in the presence of an inert organic solvent.  
     
     
         6 . The process according to  claim 1 , wherein the catalyst is introduced in a molar ratio of 1:15,000,000 to 1:10, relative to the total amount of monomer.  
     
     
         7 . The process according to  claim 1 , wherein M is Mn, Ni, Cr or Zn.  
     
     
         8 . The process according to  claim 1 , wherein A comprises anions of the formulae BF 4   − , SbX 6   − , PX 6   − , B(Ar) 4   −  or B(Ar) 4   −  anions bridged by cyclic groupings wherein Ar is a phenyl with 1 to 5 substituents.  
     
     
         9 . The process according to  claim 8 , wherein the substituent is Fl, Cl of CF 3 .  
     
     
         10 . The process according to  claim 1 , wherein R 1  is a C 1 -C 4  alkyl residue.  
     
     
         11 . The process according to  claim 11 , wherein R 1  is methyl, ethyl, propyl, butyl, isobutyl or tert-butyl.