Methods for forming amorphous ultra-high molecular weight polyolefins for use as drag reducing agents

Abstract

The present invention is directed to improved drag reducing agents and methods of forming improved drag reducing agents comprising the steps of isomerizing olefin monomers to form isomerized olefin monomers, polymerizing the isomerized olefin monomers in the presence of at least one catalyst to form a polyolefin drag reducing agent having unexpectedly superior drag reduction properties when combined with liquid hydrocarbons, such as viscous crude oil. Therefore, the drag reducing agents of the present invention may be introduced into conduits, such as pipelines, to increase the flow of the hydrocarbons through the conduit.

What is claimed is:  
     
         1 . A process for forming polyolefin drag reducing agents by polymerizing at least one olefin monomer in the presence of at least one catalyst, wherein the improvement comprises: 
 isomerizing the at least one olefin monomer prior to polymerizing the at least one olefin monomer in the presence of at least one catalyst.    
     
     
         2 . The process of  claim 1 , wherein the at least one olefin monomer includes at least one alpha olefin monomer.  
     
     
         3 . The process of  claim 2 , wherein the at least one alpha olefin monomer comprises homopolymers, terpolymers or copolymers.  
     
     
         4 . The process of  claim 2 , wherein the at least one alpha olefin monomer comprises co-polymers of 1-hexene and 1-dodecene alpha olefins or co-polymers of 1-octene and 1-tetradodecene alpha olefins.  
     
     
         5 . A process for forming a drag reducing agent comprising a substantially non-crystalline, ultra-high molecular weight polyolefin, the process comprising: 
 isomerizing olefin monomers to form isomerized olefin monomers,    wherein the isomerized olefin monomers are substantially free of branched olefin monomers;    contacting isomerized olefin monomers with a catalyst system in a reactant mixture, wherein the catalyst system includes at least one catalyst and at least one co-catalyst; and    polymerizing the isomerized olefin monomers at a temperature at about or less than 25° C., wherein during the polymerization, at least a portion of the isomerized olefin monomers polymerize in the reactant mixture to provide a substantially non-crystalline, ultra-high molecular weight polyolefin.    
     
     
         6 . The process of  claim 5 , wherein the olefin monomers are alpha olefin monomers.  
     
     
         7 . The process of  claim 6 , wherein the alpha olefin monomers comprise homopolymers, terpolymers or copolymers.  
     
     
         8 . The process of  claim 6 , wherein the alpha olefin monomers comprise co-polymers of 1-hexene and 1-dodecene alpha olefins or co-polymers of 1-octene and 1-tetradodecene alpha olefins.  
     
     
         9 . The process of  claim 5 , wherein the olefin monomers are polymerized by bulk polymerization.  
     
     
         10 . The process of  claim 5 , wherein the polymerization of the olefin monomers continues such that polyolefin is present in the reactant mixture at a concentration of at least about 4 weight percent based upon the weight of the reactant mixture, and the polyolefin includes an inherent viscosity of at least about 10 deciliters per gram.  
     
     
         11 . The process of  claim 5 , wherein the at least one co-catalyst includes an alkylaluminoxane.  
     
     
         12 . The process of  claim 11 , wherein the alkylaluminoxane is selected from the group consisting of methylaluminoxane and isobutylaluminoxane.  
     
     
         13 . The process of  claim 5 , wherein the at least one catalyst includes a the transition metal catalyst.  
     
     
         14 . The process of  claim 13 , wherein the transition metal catalyst is a non-metallocene transition metal catalyst.  
     
     
         15 . The process of  claim 14 , wherein the non-metallocene transition metal catalyst includes titanium trichloride.  
     
     
         16 . The process of  claim 5 , wherein the at least one co-catalyst includes a halohydrocarbon.  
     
     
         17 . The process of  claim 16 , wherein the halohydrocarbon is a chloride containing halohydrocarbon.  
     
     
         18 . The drag reducing agent of  claim 17 , wherein the chloride containing halohydrocarbon is ethylene dichloride.  
     
     
         19 . The process of  claim 5 , wherein the isomerized olefin monomers are polymerized by bulk polymerization.  
     
     
         20 . The process of  claim 5 , wherein the polymerization of the olefin monomers continues such that polyolefin is present in the reactant mixture at a concentration of at least about 4 weight percent based upon the weight of the reactant mixture, and the polyolefin includes an inherent viscosity of at least about 10 deciliters per gram.