Propylene polymers

摘要

This invention relates to propylene polymers comprising at least 50 mol % propylene, said polymers having: a) a melt flow rate (MFR, ASTM 1238, 230° C., 2.16 kg) of 10 dg/min to 25 dg/min; b) a Dimensionless Stress Ratio/Loss Tangent Index R2 at 190° C. from 1.5 to 28; c) an onset temperature of crystallization under flow, Tc,rheol (as determined by SAOS rheology, 190° C., 1° C./min, where said polymer has 0 wt % nucleating agent present), of at least 131° C.; d) an average meso run length determined by 13C NMR of at least 90 or higher; and e) optionally, a loss tangent, tan δ, (defined by Eq. (2)) at an angular frequency of 0.1 rad/s at 190° C. from 14 to 70.

主权项

1. A propylene polymer composition comprising at least 50 mol % propylene, said polymer composition having:
a) a melt flow rate (MFR, ASTM 1238, 230° C., 2.16 kg) of 10 dg/min to 25 dg/min; b) a Dimensionless Stress Ratio/Loss Tangent Index R2 at 190° C. from 1.5 to 28; c) an onset temperature of crystallization under flow, Tc,rheol (as determined by SAOS rheology, 1° C./min, where said polymer has 0 wt % nucleating agent present), of at least 131° C.; and d) an average meso run length determined by 13C NMR of at least 90 or 97.