PROPYLENE POLYMERS

摘要

This invention relates to propylene polymers comprising at least 50 mo1% propylene, said polymers having: a) a melt flow rate (MFR, ASTM 1238, 230°C, 2.16 kg) of 10 dg/min to 21.5 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 97 or higher; and e) optionally, a loss tangent, tan8, (defined by Eq. (2)) at an angular frequency of 0.1 rad/s at 190°C from 14 to 70.