| abstract |
(57) [Summary] (Modified) [Purpose] To provide a method for producing a propylene block copolymer having an excellent balance of impact resistance and rigidity and a high polymer falling speed. [Structure] 1) A solid catalyst component essentially containing a metal oxide, Mg, Ti, halogen and an electron donating compound, 2) a polymerization catalyst comprising an organoaluminum compound and 3) an organosilicon compound having a Si—O—C bond. The method for producing a propylene block copolymer, comprising the step (a) of polymerizing propylene in the presence of propylene and the step (b) of copolymerizing propylene and ethylene in the presence of an organosilicon compound represented by the following formula. (For example, (i-PrO) 2 Si (OMe) 2 , (t-B uO) MeSi (OMe) 2 , (t-BuO) t-Bu Si (OMe) 2 , (CyHeO) Si (OE t) 3 ). |