| abstract |
The present invention provides a propylene-based block copolymer having high melt viscoelasticity, excellent balance between rigidity and impact resistance, good molding processability, and excellent molded product appearance, a composition containing the copolymer, and molded products obtained therefrom. The propylene-based block copolymer comprises 5 to 80% by weight of a room temperature n-decane-soluble portion (Dsol) and 20 to 95% by weight of a room temperature n-decane-insoluble portion (Dinsol) (the total amount of the Dsol and the Dinsol is 100% by weight), and satisfies the requirements [1] to [3]: [1] the molecular weight distribution (Mw/Mn) of the Dsol is 7.0 to 30, [2] the molecular weight distribution (Mw/Mn) of the Dinsol is 7.0 to 30, and Mz/Mw thereof is 6.0 to 20, and [3] the pentad fraction (mmmm) of the Dinsol is not less than 93%. |