To provide a method of producing a propylene-based block copolymer capable of easily controlling molecular weight of the polypropylene component by a small quantity of hydrogen, and forming a high-molecular-weight ethylene/ propylene copolymer component.
This method comprises producing a propylene-based block copolymer using an olefin polymerization catalyst composed of (A) a preliminary polymerization catalyst component brought into contact with an olefin in the presence of (a) a solid catalyst component obtained by bringing titanium tetrachloride, a magnesium compound and dialkyl phthalate into contact with each other, (b) an organometallic compound and (c) an organosilicon compound having the Si-O-C bond, (B) an organometallic compound, and (C) an organosilicon compound shown by general formula (1) (R1 is a 3-12C alicyclic hydrocarbon group; R2 is a 3-20C branched hydrocarbon group: and R3 is a 1-20C hydrocarbon group) and different from the above-described (c).
KATAYAMA KIYOKAZU
OBATA HIROSHI
OTA TAKESHI
FUNABASHI HIDEO
