Patent ID: 7205371

Claim:
A copolymer comprising from 5 wt % to 25 wt % of ethylene-derived units and from 95 wt % to 75 wt % of propylene-derived units, the copolymer having: a) a triad tacticity as determined by 13 C NMR of greater than 75%; b) a tacticity index m/r of from 4 to 12; c) a proportion of inversely inserted propylene units based on 2,1 insertion of propylene monomer in all propylene insertions, as measured by 13 C NMR, of greater than 0.5%; d) a proportion of inversely inserted propylene units based on 1,3 insertion of propylene monomer in all propylene insertions, as measured by 13 C NMR, of greater than 0.05%; and e) an intermolecular tacticity such that at least 75 wt % of the copolymer is soluble in two adjacent temperature fractions of a thermal fractionation carried out in hexane in 8° C. increments.