| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing propylene block copolymers capable of producing propylene block copolymers excellent in the balance between rigidity and impact resistance. SOLUTION: This production process of a propylene block copolymer comprises producing a propylene homopolymer or a propylene copolymer containing >=90 mole % propylene in a first step by polymerizing propylene itself or propylene and anα-olefin having 2-20 carbon atoms in the presence of a catalyst consisting of [A] a transition metal compound expressed by the general formula below and [B] an ion exchanging layered compound except silicates or inorganic silicates as essential ingredients and [C] an organoaluminum compound as an arbitrary ingredient, and, in a second step, copolymerizing propylene with the olefin having 2-20 carbon atoms in the presence of the polymer produced in the first process. (A<1> and A<2> are each a conjugated five membered ring ligand. A<1> and A<2> are either equal or different in the same molecule).
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