Ethylene-Propylene Copolymeric Compositions With Long Methylene Sequence Lengths

Abstract

This invention relates to methods to prepare and compositions pertaining to branched ethylene-propylene copolymers that include at least 50% ethylene content by weight as determined by FTIR; a g′ vis of less than 0.95; a M W of 150,000 to 250,000; a methylene sequence length of 6 or greater as determined by 13 C NMR, wherein the percentage of sequences of the length of 6 or greater is more than 32%; and can have greater than 50% vinyl chain end functionality.

1 . A branched ethylene-propylene copolymer comprising:
 at least 50% ethylene content by weight as determined by FTIR;   a g′ vis  of less than 0.98;   a methylene sequence length of 6 or greater as determined by  13 C NMR, wherein the percentage of sequences of the length of 6 or greater is more than 32%; and   greater than 50% vinyl chain end functionality is present.   
     
     
         2 . The branched ethylene-propylene copolymer of  claim 1 , wherein the g′ vis  is less than 0.95. 
     
     
         3 . The branched ethylene-propylene copolymer of  claim 1 , wherein the ethylene-propylene copolymer has a ratio of percentage of saturated chain ends to percentage of vinyl chain that is greater than 1. 
     
     
         4 . The branched ethylene-propylene copolymer  claim 1 , wherein the ethylene-propylene copolymer has a heat of fusion from 5 J/g to 50 J/g. 
     
     
         5 . The branched ethylene-propylene copolymer of  claim 1 , wherein the ethylene-propylene copolymer T m  is from −10° C. to 40° C. 
     
     
         6 . The branched ethylene-propylene copolymer of  claim 1 , wherein the ethylene-propylene copolymer has a Mooney viscosity (ML) range at 125° C. of from 29 to 100 Mooney units (MU). 
     
     
         7 . The branched ethylene-propylene copolymer of  claim 1 , wherein the branched ethylene-propylene copolymer has a Mooney large relaxation area (MLRA) of from 100 to 1000. 
     
     
         8 . The branched ethylene-propylene copolymer of  claim 1 , wherein the r 1 r 2  is greater than 2. 
     
     
         9 . The branched ethylene-propylene copolymer of  claim 1 , wherein the branched ethylene-propylene copolymer has an elongation (break) of at least 150%. 
     
     
         10 . The branched ethylene-propylene copolymer of  claim 1 , wherein the branched ethylene-propylene copolymer has a nomial stress range of from 0.22 MPa to 0.32 MPa at a 50% strain and 0.15 MPa to 0.2 MPa at 150% strain, at a pull rate of 5.08 centimeters/minute. 
     
     
         11 . The branched ethylene-propylene copolymer of  claim 1 , wherein the branched ethylene-propylene copolymer ethylene content is from 50% to 55%. 
     
     
         12 . A process for the preparation of the ethylene/propylene branched polymer of  claim 1 , wherein the process comprises:
 contacting ethylene and propylene, under polymerization conditions, with at least a catalyst system comprising an activator and at least one metallocene and   obtaining a branched ethylene/propylene copolymer having at least 50% ethylene content by weight as determined by FTIR;   a g′ vis  of less than 0.98;   a methylene sequence length of 6 or greater as determined by  13 C NMR, wherein the percentage of sequences of the length of 6 or greater is more than 32%; and   greater than 50% vinyl chain end functionality is present.   
     
     
         13 . The process of  claim 12 , wherein the process is a solution process. 
     
     
         14 . The process of  claim 12 , wherein the metallocene compound is represented by the formula: 
       
         
           
           
               
               
           
         
         where each R 3  is hydrogen; each R 4  is independently a C 1 -C 10  alkyl; each R 2 , and R 7  are independently hydrogen, or C 1 -C 10  alkyl; each R 5  and R 6  are independently hydrogen, or C 1 -C 50  substituted or unsubstituted hydrocarbyl and R 4  and R 5 , R 5  and R 6  and/or R 6  and R 7  may optionally be bonded together to form a ring structure; J is a bridging group represented by the formula Ra 2 J, where J is C or Si, and each Ra is, independently C 1  to C 20  substituted or unsubstituted hydrocarbyl, and two R a  form a cyclic structure incorporating J and the cyclic structure may be a saturated or partially saturated cyclic or fused ring system; and each X is is a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand. 
       
     
     
         15 . The process of  claim 12 , wherein the metallocene compound is one or more of:
 cyclotetramethylenesilylenebis(2,4,7-trimethyl-indenyl)hafnium dimethyl,   cyclotrimethylenesilylenebis(2,4,7-trimethyl-indenyl)hafnium dimethyl,   cyclotetramethylenesilylenebis(2,4,7-trimethyl-indenyl)hafnium dichloride,   cyclotrimethylenesilylenebis(2,4,7-trimethyl-indenyl)hafnium dichloride, or mixtures thereof.   
     
     
         16 . The process of  claim 12 , wherein the activator is dimethylanilinium tetrakisperfluoronaphthylborate.