| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a propylene-based block copolymer to stably obtain a polymer with a high productivity by increasing the molecular weight of a copolymer component and increasing catalytic activity without excessively purging hydrogen gas in a continuous gas phase process.SOLUTION: There is provided a method for producing a propylene-based block copolymer which comprises steps (I) and (II) in the presence of a solid catalyst component (A), where a component (B) is added in the step (I), a hydrogen concentration is adjusted in the range of 50 to 500 ppm in the step (II) and the weight average molecular weight is adjusted to 1800000 or more. Component (A): a solid catalyst component, (I) a first step of homocopolymerizing propylene or copolymerizing ethylene or an α-olefin having 4 or more carbon atoms at more than 0 and less than 10 wt.% with propylene, (II) a second step of polymerizing propylene with ethylene or an α-olefin having 4 or more carbon atoms at 10 to 90 wt.%, Component (B): an organic aluminum compound (1) RAlX(OR)(1). |
