To provide a method for producing a propylenic block copolymer having excellent powder property, appearance and mechanical properties in the presence of a catalyst having excellent activity and stereoregularity.
This method for producing a propylenic block copolymer, comprising the first stage polymerization process for polymerizing an α-olefin consisting mainly of propylene in the presence of a stereoregular catalyst and the second stage polymerization process for copolymerizing the propylene with an α-olefin except the propylene under the action of the stereoregular catalyst used in the first stage polymerization process, characterized by using a catalyst comprising the following components (A), (B) and (C) as the stereoregular catalyst. (A) A solid catalyst component prepared by bringing a solid component consisting essentially of titanium, magnesium, a halogen and an electron-donating compound into contact with a compound of the general formula: (R1)(R2)3-mSi(OR3)m. (B) An organic aluminum compound. (C) An organic silicon compound represented by the general formula: (R4)4-nSi(OR5)n.
SHIMIZU FUMIHIKO
HOSOI ATSUSHI
