| 摘要 |
PROBLEM TO BE SOLVED: To produce a propylene block copolymer which can give a molding having excellent appearance and impact resistance. SOLUTION: In the 1st stage of polymerization, ethylene is copolymerized with propylene in the presence of an olefin polymerization catalyst in liquid propylene to produce a lowly crystalline or amorphous polymer containing 10-70mol% structural units derived from ethylene and having an intrinsic viscosity [ν] of 5-30dl/g. In the 2nd stage of polymerization, propylene is homopolymerized or propylene, ethylene and/or a 4-10Cα-olefin are copolymerized in the presence of the obtained polymer to produce 98-60wt.%, based on the finally obtained block copolymer, crystalline polymer.
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