PURPOSE: To obtain the subject copolymer excellent in impact resistance, rigidity, and appearance, and useful for moldings, etc., by block-copolymerizing ethylene- propylene copolymer with highly crystalline PP produced by polymerizing propylene in the presence of a specific catalyst.
CONSTITUTION: Highly crystalline PP preferably in an amount of 70-95wt.% is block-copolymerized with propylene-ethylene copolymer preferably in an amount of 30-5wt.% to provide the objective copolymer. The highly crystalline PP is produced by polymerizing propylene in the presence of a polymerization catalyst comprising (A) a solid catalyst component containing a metal oxide, magnesium, titanium, a halogen and an electron-donating compound as essential components, (B) an organometallic compound such as triethyl aluminum, and (C) an organosilicon compound of the formula [R1, R2 are 1-10C hydrocarbon, OR4, OSiR5, SiR6 (R4-R6 are R1); R3 is 1-10C divalent hydrocarbon].
AOKI TOMOKO
IMANISHI KUNIHIKO
UEKI SATOSHI
SAITO HIROO
TAKI NORIYUKI
