| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for preparing a polypropylene random copolymer which has a high MFR and is excellent in transparency with a high productivity. <P>SOLUTION: The polypropylene random copolymer is prepared by copolymerizing propylene and at least one comonomer comprising ethylene and a 4-12C olefin by a gas phase polymerization method in the presence of a solid catalyst, provided that the reaction heat in the gas phase polymerization method is mainly removed by vaporization heat of liquefied propylene. The solid catalyst is obtained by catalytically treating a solid component containing titanium, magnesium and a halogen, a vinylsilane compound and an organosilicon compound having an alkoxy group and/or a compound having at least two ether bonds. The desired copolymer has a comonomer unit content of 0.1-10 mass% and a MFR measured at 230°C under a load of 21.18 N of 10-1,000 g/10 min. <P>COPYRIGHT: (C)2008,JPO&INPIT |
