Nickel-containing ethylene oligomerization catalyst and use thereof

Abstract

A process for the oligomerization of ethylene to a mixture of olefinic products having high linearity is provided, by using a catalyst comprising a reaction product of a simple divalent nickel salt; a boron hydride reducing agent; a water soluble base; a ligand selected from an o-dihydrocarbylphosphinobenzoic acid and alkali metal salt thereof; and, a phosphite.

1 - 22 . (canceled).  
     
     
         22 . A process for the preparation of a mixture of olefinic products having high linearity comprising: 
 A) contacting ethylene in a polar organic solvent under conditions effective to produce linear, alpha-olefins in the presence of a catalyst produced by reacting components comprising:    a) a simple divalent nickel salt having a solubility of at least 0.001 mole per liter in said polar organic solvent;    b) a boron hydride reducing agent;    c) a water soluble base;    d) a ligand selected from the group consisting of o-dihydrocarbylphosphinobenzoic acids and alkali metal salts thereof; and,    e) a trivalent phosphite, wherein the molar ratio of the ligand to the trivalent phosphite ranges from about 50:1 to about 1000:1;    thereby producing a mixture of olefinic products having high linearity; and    B) recovering the olefinic products having high linearity.    
     
     
         23 . The process of  claim 22  in which the process is carried out at a temperature of between about 0° and about 200° C.  
     
     
         24 . The process of  claim 22  in which the nickel salt comprises a nickel halide.  
     
     
         25 . The process of  claim 22  in which the nickel salt comprises a nickel alkanoate.  
     
     
         26 . The process of  claim 22  in which the boron hydride reducing agent is an alkali metal borohydride.  
     
     
         27 . The process of  claim 22  in which the water soluble base is selected from the group consisting of potassium bicarbonate, potassium methoxide, potassium ethoxide, potassium isopropoxide, potassium hydroxide, potassium tert-butoxide, sodium bicarbonate, sodium methoxide, sodium ethoxide, sodium isopropoxide, sodium hydroxide and sodium tert-butoxide.  
     
     
         28 . The process of  claim 22  in which the water soluble base is potassium hydroxide.  
     
     
         29 . The process of  claim 22  in which the trivalent phosphite is an alkyl phosphite  
     
     
         30 . The process of  claim 22  in which the trivalent phosphite is triethyl phosphite.  
     
     
         31 . The process of  claim 22  in which the ligand is selected from the group consisting of diarylphosphinobenzoic acids, arylcycloalkylphosphinobenzoic acids and the alkali metal salts thereof.  
     
     
         32 . The process of  claim 23  in which the nickel salt comprises a nickel halide, the boron hydride reducing agent is an alkali metal borohydride, the water soluble base is a potassium hydroxide, the trivalent phosphite is triethyl phosphite and the ligand is o-dihydrocarbylphosphinobenzoic acid.