Propylene-based copolymer, process for producing the same and film comprising the same

摘要

A propylene-based copolymer obtained by copolymerizing propylene with ethylene and/or an alpha-olefins having 4 or more carbon atoms in the presence of a polymerization catalyst in a first step to produce a copolymer having a content of the alpha-olefins of 1 mol % or more and less than 15 mol % and an ethylene content of 5 mol % or less in amount of 1 to 30% by weight as a copolymer component (A), and subsequently copolymerizing propylene with ethylene and/or an alpha-olefins having 4 or more carbon atoms in a second step or later steps to produce a copolymer having a content of the alpha-olefins of 15 to 30 mol % and an ethylene content of 5 mol % or less in amount of 70 to 99% by weight as a copolymer component (B).