Patent ID: 8288480

Claim:
An in-reactor polymer blend comprising at least 60 mole % of propylene and from 0.01 to 10 mole % of at least one diene selected from the group consisting of C 6 to C 12 Î±,Ï‰-dienes, norbornadiene, vinyl norbornene and mixtures thereof with the balance being ethylene, wherein the blend comprises first and second polymers having different crystallinities and glass transition in which at least the second polymer comprises at least one branch of the first polymer per 10,000 carbon atoms of the in-reactor blend as observed by 13 C NMR, wherein the blend has the following properties: a) a highest melting temperature of 120Â° C. or more and a lowest glass transition temperature of âˆ’20Â° C. or less as determined by Differential Scanning Calorimetry; (b) a branching index (gâ€²) of 0.9 or less as determined by the formula: g â€² = Î· b Î· l where Î· b is the intrinsic viscosity of the in-reactor polymer blend and Î· 1 is the intrinsic viscosity of a linear polypropylene of the same viscosity-averaged molecular weight (M v ) as the in-reactor polymer blend, where Î· 1 =KM v Î± , where K=0.0002288 and Î±=0.705; (c) a critical relaxation exponent, n, of greater than 0 and less or equal to 0.8; and (d) at least 90 wt, % of the blend is soluble in refluxing xylenes at 138Â° C.