Process for the preparation of isoolefin copolymers

Abstract

The present invention provides a novel process for the preparation of isoolefin copolymers in the presence of zirconium halides and/or hafnium halides and organic acid halides, in particular for the preparation of butyl rubbers, as well as isoolefin copolymers constructed of isobutene, isoprene and optionally further monomers.

What is claimed is:  
     
         1 . A process for the preparation of isoolefin copolymers in the presence of zirconium halides and/or hafnium halides, comprising the step of polymerizing monomers in the presence of organic acid halides.  
     
     
         2 . A process according to  claim 1 , wherein said organic acid halide corresponds to the general formula (I)  
       R—COX  (I),  wherein R is selected from the group consisting of C 1 -C 18 -alkyl, C 3 -C 18 -cycloalkyl and C 6 -C 24 -cycloaryl, and X may be fluorine, chlorine, bromine or iodine.    
     
     
         3 . A process according to  claim 1  wherein the concentration of the organic acid halide in the reaction medium is within the range of 1 to 500 ppm.  
     
     
         4 . A process according to  claim 1 , wherein said zirconium halide is ZrCl 4  and said hafnium halide is HfCl 4 .  
     
     
         5 . A process according to  claim 1 , wherein isobutene is copolymerized with isoprene and optionally further monomers.  
     
     
         6 . A process according to  claim 1 , wherein AlCl 3  or a catalyst system which is preparable from AlCl 3  is additionally utilized.  
     
     
         7 . A mixture of zirconium halide and/or hafnium halide and organic acid halide corresponding to the general formula (I)  
       R—COX  (I),  wherein R is selected from the group consisting of C 1 -C 18 -alkyl, C 3 -C 18 -cycloalkyl and C 6 -C 24 -cycloaryl, and X may be fluorine, chlorine, bromine or iodine.    
     
     
         8 . A catalyst comprising a mixture of zirconium halide and/or hafnium halide and organic acid halide corresponding to the general formula (I)  
       R—COX  (I),  wherein R is selected from the group consisting of C 1 -C 18 -alkyl, C 3 -C 18 -cycloalkyl and C 6 -C 24 -cycloaryl, and X may be fluorine, chlorine, bromine or iodine.    
     
     
         9 . A polymer which is prepared by the polymerization of monomers in the presence of i) zirconium halides and/or hafnium halides, and also ii) organic acid halides.  
     
     
         10 . A polymer according to  claim 9 , wherein said organic acid halide corresponds to the general formula (I)  
       R—COX  (I),  wherein R is selected from the group consisting of C 1 -C 18 -alkyl, C 3 -C 18 -cycloalkyl and C 6 -C 24 -cycloaryl, and X may be fluorine, chlorine, bromine or iodine.    
     
     
         11 . A polymer according to  claim 9 , wherein the concentration of the organic acid halide in the reaction medium is within the range of 1 to 500 ppm.  
     
     
         12 . A polymer according to  claim 9 , wherein said zirconium halide is ZrCl 4  and said hafnium halide is HfCl 4 .  
     
     
         13 . A polymer according to  claim 9 , wherein isobutene is copolymerized with isoprene and optionally further monomers.  
     
     
         14 . A polymer according to  claim 9 , wherein AlCl 3  or a catalyst system which is preparable from AlCl 3  is additionally utilized.  
     
     
         15 . A polymer according to  claim 9 , comprising up to 30 mol % isoprene.  
     
     
         16 . A molded body comprising a polymer which is prepared by the polymerization of monomers in the presence of 
 i) zirconium halides and/or hafnium halides, and also 
 ii) organic acid halide.