CRYSTALLINE POLYPROPYLENE, PROCESS FOR PREPARING THE SAME, POLYPROPYLENE COMPOSITION, AND THERMOFORMED ARTICLE

摘要

A crystalline polypropylene which meets the following property requirements (1 to 4), contains a component insoluble in decane at 64 ~C, is excellent particularly in hardness and rigidity, and has high melt tension and excellent moldability; a process for preparing the same; and a polypropylene composition and a thermoformed article comprising the above crystalline polypropylene: (1) an intrinsic viscosity ¢! (in decaline at 135 ~C) of 0.5 to 10 dl/g; (2) a molecular weight distribution (Mz/Mw) of at least 5 as determined by gel permeation chromatography (GPC; o-chlorobenzene solvent, measurement temp. 140 ~C); (3) a pendat isotacticity (mmmm fraction), an index of stereotacticity, of at least 98 % as determined by 13C-NMR spectroscopy; and (4) a D value of at least 4.0 as determined by the equation (I) based on loss tan .delta.0.05 and loss tan .delta.10 as measured at a temperature of 230 ~C under constant strain by means of a melt viscoelasticity measuring instrument at frequencies of 0.05 rad/sec and 10 rad/sec. The number-average molecular weight of the component insoluble in decane at 64 ~C is at most 25000.