Low-metal content ethylene-alpha olefin copolymers and functionalized products made therefrom

Abstract

A copolymer including ethylene units and units of one or more C 3-10 alpha-olefins. The copolymer has a number average molecular weight of less than 5,000 g/mol, as measured by GPC. The copolymers have low metal (ash) and/or fluorine contents.The ethylene content of the copolymer is less than 80 mol %. 70 mol % or greater of the copolymer has a carbon-carbon double bond in a terminal monomer unit, and at least 70 mol % of the terminal monomer units that have a carbon-carbon double bond have a terminal group selected from a vinylidene group and a tri-substituted isomer of a vinylidene group. The copolymer has a crossover temperature of −20° C. or lower and/or a certain ethylene run length. Also disclosed are a method for making the copolymer and polyolefins plasticized with 1-40 wt. % of the copolymer as well as methods of fanctionalizing the copolymer and products made with the functionalized coploymer.

What is claimed is: 
     
         1 . A copolymer comprising ethylene units and units of one or more C 3 -C 10  alpha-olefins,
 wherein the copolymer has a number average molecular weight of less than 5,000 g/mol as measured by GPC;   wherein the ethylene content of the copolymer is less than 80 mol %;   wherein 85 mol % or greater of the copolymer has a carbon-carbon double bond in a terminal monomer unit and at least 70 mol % of the terminal monomer units that have the carbon-carbon double bond have a terminal group selected from a vinylidene group and a tri-substituted isomer of a vinylidene group selected from the following structural formulas (A)-(C):   
       
         
           
           
               
               
           
         
       
       wherein R represents a C 1 -C 8  alkyl group and 
       
         
           
           
               
               
           
         
       
       indicates a bond that is attached to a remaining portion of the copolymer; and
 a metal content of 25 ppmw or less, based on the total weight of the copolymer. 
 
     
     
         2 . The copolymer of  claim 1 , wherein the metal content of the copolymer is 25 ppmw or less of zirconium, boron and aluminum, based on the total weight of the copolymer. 
     
     
         3 . The copolymer of  claim 1  the copolymer metal content is derived from a copolymerization catalyst and is 25 ppmw or less of zirconium, based on the total weight of the copolymer. 
     
     
         4 . The copolymer of  claim 1  the copolymer metal content is derived from a copolymerization catalyst and is 25 ppmw or less of boron, based on the total weight of the copolymer. 
     
     
         5 . The copolymer of  claim 1  the copolymer metal content is derived from a copolymerization catalyst and is 25 ppmw or less of aluminum, based on the total weight of the copolymer. 
     
     
         6 . The copolymer of  claim 1 , wherein the metal content of the copolymer is 10 ppmw or less, based on the total weight of the copolymer. 
     
     
         7 . The copolymer of  claim 1 , wherein the metal content of the copolymer is 5 ppmw or less, based on the total weight of the copolymer. 
     
     
         8 . The copolymer of  claim 1 , wherein the metal content of the copolymer is 1 ppmw or less, based on the total weight of the copolymer. 
     
     
         9 . The copolymer of  claim 1 , wherein the copolymer has a fluorine content of less than 10 ppmw, based on the total weight of the copolymer. 
     
     
         10 . The copolymer of  claim 1 , wherein the copolymer has a fluorine content of less than 8 ppmw, based on the total weight of the copolymer. 
     
     
         11 . The copolymer of  claim 1 , wherein the copolymer has a fluorine content of less than 5 ppmw, based on the total weight of the copolymer. 
     
     
         12 . The copolymer of  claim 1 , wherein the copolymer has an average ethylene derived unit run length (n C2 ) which is less than 2.8, as determined by  13 C NMR spectroscopy, the average ethylene-derived unit run length n C2  is defined as the total number of ethylene-derived units in the copolymer divided by a number of runs of one or more sequential ethylene-derived units in the copolymer, and the average ethylene derived unit run length n C2  also satisfies the relationship shown by the expression below: 
       
         
           
             
               
                 n 
                 
                   C 
                    
                   
                       
                   
                    
                   2 
                 
               
               < 
               
                 
                   ( 
                   
                     EEE 
                     + 
                     EEA 
                     + 
                     AEA 
                   
                   ) 
                 
                 
                   ( 
                   
                     AEA 
                     + 
                     
                       0.5 
                        
                       EEA 
                     
                   
                   ) 
                 
               
             
           
         
       
       wherein
 EEE=(x C2 ) 3    
 EEE=(x C2 ) 3    
 AEA=x C2 (1−x C2 ) 2    
 
       x C2  being the mole fraction of ethylene incorporated in the copolymer as measured by  1 H-NMR spectroscopy, E representing an ethylene unit, and A representing an alpha olefin unit. 
     
     
         13 . The copolymer of  claim 1 , wherein the copolymer has a crossover temperature of −20° C. or lower. 
     
     
         14 . The copolymer of  claim 1 , wherein the ethylene content of the copolymer is at least 10 mol % and less than 70 mol % and the C 3 -C 10  alpha-olefin content of the copolymer is at least 40 mol % of propylene. 
     
     
         15 . The copolymer of  claim 12 , wherein the copolymer has an average ethylene unit derived run length of less than 2.6. 
     
     
         16 . The copolymer of  claim 1 , wherein the copolymer has a polydispersity index of less than or equal to 4. 
     
     
         17 . The copolymer of  claim 1 , wherein the number average molecular weight of the copolymer is between 800 and 4,000 g/mol, as measured by GPC. 
     
     
         18 . The copolymer of  claim 1 , wherein less than 20% of unit triads in the copolymer are ethylene-ethylene-ethylene triads. 
     
     
         19 . The copolymer of  claim 1 , wherein the copolymer is an ethylene-propylene copolymer and has a number average molecular weight less than 3,500 g/mol, as measured by GPC. 
     
     
         20 . The copolymer of  claim 1 , wherein:
 (a) the ethylene content of the copolymer is at least 10 mol % and less than 70 mol %,   (b) the C 3 -C 10  alpha-olefin content of the copolymer is at least 40 mol % of propylene,   (c) at least 85 mol % of the copolymer terminates in the terminal vinylidene group or the tri-substituted isomer of the terminal vinylidene group,   (d) the copolymer has an average ethylene unit run length of less than 2.4.   (e) the crossover temperature of the copolymer is −30° C. or lower.   (f) the copolymer of  claim 1 , wherein the copolymer has a polydispersity index of less than or equal to 4,   (g) the number average molecular weight of the copolymer is between 800 and 4,000 g/mol, as measured by GPC, and   (h) less than 20% of unit triads in the copolymer are ethylene-ethylene-ethylene triads.