| 摘要 |
PURPOSE:To obtain the title PP which can give a high-rigidity molding high in nerve, reduced in wall thickness and excellent in scratch and chemical resistance without using any nucleator, by polymerizing C3H6 at a low temperature in the absence of any MW modifier so that specified conditions such as a relationship between the MFR and the absorbance ratio may be satisfied. CONSTITUTION:The title PP is obtained by polymerizing C3H6 so that the MFR may be 0.1-200g/10min (at 230 deg.C), that this MFR and the absorbance ratio (IR<-tau>: a ratio of the absorbance at a wavenumber of 997cm<-1> to that at a wavenumber of 973cm<-1>) satisfy the relationship of the formula, that the IR<-tau> of the initial 2-3wt.% portion of a deposit formed when a dilute xylene solution of the obtained PP is gradually cooled with agitation may be 0.97 or above and that the ratio of the weight-average molecular weight of this portion to the weight-average MW of the obtained PP may be 3 or above by a polymerization process partly consisting of a step of polymerizing C3H6 at a relatively low temperature of room temperature to 60 deg.C in the absence of any MW modifier such as H2 gas. |
