POLYDISPERSE PROPYLENE POLYMER AND PROCESS FOR PRODUCING THE SAME

摘要

A polydisperse propylene polymer characterized by being produced by polymerizing a propylene monomer or a monomer mixture of propylene and an olefin by multistage polymerization where the polymerization conditions are gradationally changed in the presence of a metallocene-containing catalyst obtained by depositing on a finely particulate support either a transition metal compound and an aluminoxane or a reaction product obtained from these and also an organoaluminum as a scavenger, and by having a weight-average molecular weight to number-average molecular weight ratio (Mw/Mn) of 4.0 or higher, a melting point (Tm) of 165 DEG C or lower, and a difference between the melting point (Tm) and the heat distortion temperature (HDT) of 30 DEG C or smaller.