| abstract |
A method for producing a propylene-based block copolymer in which stickiness and bleed-out are suppressed is provided. [Solution] Using the supported metallocene catalyst, the propylene-based polymer component (A) is added in the first step, and then the propylene-α-olefin random copolymer component (B) having a higher α-olefin content than the propylene-based polymer component (A). The present invention provides a method for producing a propylene-based block copolymer which is sequentially polymerized in two steps and satisfies the following (i) to (iv). (I) The average particle size of the polymer particles at the start of the second step is 700 μm or more, (Ii) The ratio [W (B)] of the copolymer component (B) to the total amount of the copolymer is 3 to 95% by mass; (Iii) The α-olefin content [E (B)] of the copolymer component (B) is 3 to 90% by mass, (Iv) The melting point [Tm (A)] of the propylene-based polymer component (A) is less than 143 ° C. [Selection figure] None |