| abstract |
Disclosed are a polypropylene-based block copolymer having a high melt viscoelasticity, an excellent balance between stiffness and impact resistance, good molding processability, and an extremely excellent molded appearance, a composition containing said copolymer, and a molded body obtained therefrom. This polypropylene-based block copolymer is comprised of 5-80 wt% of a portion that is soluble in room-temperature n-decane (Dsol) and 20-95 wt% of a portion that is insoluble in room-temperature n-decane (Dinsol), while simultaneously meeting the following requirements (1)-(3):n(1) The molecular weight distribution (Mw/Mn) of the Dsol is at least 7.0 and not greater than 30;n(2) the molecular weight distribution (Mw/Mn) of the Dinsol is at least 7.0 and not greater than 30 and Mz/Mw is at least 6.0 and not greater than 20;n(3) the pentad fraction (mmmm) of the Dinsol is 93% or higher. |