METHOD FOR PRODUCING THE CRYSTALLINE POLYPROPYLENE HAVING A HIGH STEREOREGULARITY

摘要

A highly crystalline polypropylene (PP) from which highly stiff molded products can be produced and also which can be used for use applications for which conventional PP could not have been used is provided, which PP is chracterized by the following conditions (A) and (B): (A) its melt flow rate (MFR) and absorbance ratio according to the method of infrared absorption spectra (IR tau ; an absorbance ratio of a wave-number of infrared rays of 997 cm<-><1> to that of 973 cm<-><1>) satisfy an equation of IR- tau >/=0.0203 log MFR + 0.950 and its MFR is in the range of 0.1 to 200; and (B) when a dilute solution of the PP dissolved in xylene is slowly cooled with stirring, an initially deposited component in 2 to 3% by weight has an IR- tau value of 0.97 or more and the weight average M.W. (Mw1) of the deposited components and that (Mwo) of the PP have a ratio of 3 or more.