Process for preparing and using meso/racemic-[bis (indenyl) ethane] zirconium dichloride compounds

Abstract

A process for the preparing of a meso/racemic-(bis(indenyl)ethanel zirconium dichloride compound comprising (a) reacting zirconium tetrachloride with the solid reaction product of the bis(indenyl)ethane ligand with an alkyllithium in a solvent as reaction medium and (b) recovering a solid mixture of lithium chloride and meso/racemic composition of [bis(indenyl)ethane] zirconium dichloride, characterized in that the solvent used as reaction medium in a reaction (a) is an ether, pentane or a mixture thereof.

What is claimed as new and desired to be secured by Letter of Patent of the United Stated of America is:  
     
         1 . A process for the preparation of a meso/racemic-[bis(indenyl)ethane]zirconium dichloride compound comprising (a) reacting zirconium tetrachloride with the solid reaction product of a bis(indenyl)ethane ligand with an alkyllithium in a solvent as reaction medium and (b) recovering a solid mixture of lithium chloride and a meso/racemic composition of [bis(indenyl)ethane]zirconium dichloride, wherein the solvent used as reaction medium in reaction (a) is an ether, pentane or a mixture thereof.  
     
     
         2 . A process according to  claim 1 , wherein the ether is diethyl ether.  
     
     
         3 . A process according to  claim 1 , wherein the reaction (a) is carried out under stirring at a temperature from 15 to 30° C.  
     
     
         4 . A process according to  claim 3 , wherein the duration of said reaction (a) is between 1 and 3 hours.  
     
     
         5 . A process according to  claim 4 , wherein said duration is of about 2 hours.  
     
     
         6 . A process according claims  1 , wherein the reaction product of the ligand with an alkyllithium is added as a powder.  
     
     
         7 . A process according  claim 1 , wherein said meso/racemic composition is separated from lithium chloride with an extractant solvent.  
     
     
         8 . A process according to  claim 7 , wherein the extractant solvent is methylene chloride or dichloromethane.  
     
     
         9 . A process according to  claim 8 , wherein the extractant solvent is methylene chloride in order to obtain a meso/racemic composition of 50/50.  
     
     
         10 . A process according to  claim 8 , wherein the extractant solvent is dichloromethane in order to obtain a meso/racemic composition of 75/25.  
     
     
         11 . A process according to claims  1 , wherein the bis(indenyl)ethane ligand is selected from the 2,2′-substituted and 2,2′, 4,4′-substituted indenyl ligands.  
     
     
         12 . A process according to  claim 1  additionally comprising supporting the meso/racemic-[bis(indenyl)ethane]zirconium dichloride compound on a support.  
     
     
         13 . A process according to  claim 12 , wherein the support is a silica having a surface area comprised between 200 and 600 m 2 /g and a pore volume comprised between 0.5 and 4.5 ml/g.  
     
     
         14 . A process for the polymerization or copolymerization of olefins comprising contacting at least one olefinic monomer with a catalyst which is a reaction product of: 
 a) a bis(indenyl)ethane ligand with an alkyllithium in a solvent; and    b) zirconium tetrachloride,    wherein the solvent is an ether, pentane or a mixture thereof.    
     
     
         15 . A process accordion to  claim 14 , wherein the catalyst comprises a meso/racemic-[bis(indenyl)ethane]zirconium dichloride compound.  
     
     
         16 . A process according to  claim 14 , wherein the olefinic monomer is ethylene or propylene.  
     
     
         17 . A process according to  claim 14 , wherein the catalyst is in a supported form.  
     
     
         18 . A process according to  claim 17 , wherein the catalyst is supported on a silica having a surface area comprised between 200 and 600 m 2 /g and a pore volume comprised between 0.5 and 4.5 ml/g.  
     
     
         19 . A catalyst comprising a reaction product of 
 (a) a bis(indenyl)ethane ligand with an alkyllithium in a solvent; and    (b) zirconium tetrachloride,    wherein the solvent is an ether, pentane or a mixture thereof.    
     
     
         20 . A catalyst according to  claim 19 , wherein the reaction product is a meso/racemic-[bis(indenyl)ethane]zirconium dichloride compound.  
     
     
         21 . A catalyst according to  claim 19 , wherein the ether is diethyl ether.  
     
     
         22 . A catalyst according to  claim 19 , wherein the bis(indenyl)ethane ligand is selected from the 2,2′-substituted and 2,2′, 4,4′-substituted indenyl ligands.  
     
     
         23 . A catalyst according to  claim 19 , additionally comprising c) a support.  
     
     
         24 . A catalyst according to  claim 23 , wherein the support is a silica having a surface area comprised between 200 and 600 m 2 /g and a pore volume comprised between 0.5 and 4.5 ml/g.