POLYPROPYLENE COMPOSITION

摘要

Disclosed is a polypropylene composition excellent in balance of low temperature impact-strength, rigidity, heat-resisting property and transparency, which is featured by comprising 20-95% by weight of a polypropylene defined in the following ÄIÜ and 5-80% by weight of a propylene- alpha -olefin copolymer defined in the following ÄIIÜ: ÄIÜ a polypropylene featured by having: (1) a ratio of isotactic pentad (mmmm) is 0.900 - 0.949, (2) the 2,1- and 1,3-propylene units in the polymer chain is 0-1 mole %, (3) a weight average molecular weight (Mw) is 40,000-1,000,000, (4) a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn), i.e. (Mw)/(Mn) is 1.5-3.8, and (5) in case of elevating the temperature of o-dichlorobenzene continuously or stepwise up to given temperatures to measure the amount of eluted polypropylene at each temperature, the position of a main elution peak is 95-110 DEG C and the amount of components existing in the range of +/-10 DEG C of the main elution peak is at least 90% of the total amounts of components eluted at a temperature higher than 0 DEG C, and ÄIIÜ a propylene- alpha -olefin copolymer containing 10-90% by weight of a constituent derived from propylene and 10-90% by weight of a constituent derived from alpha -olefin other than propylene.