PROPYLENE RESIN FILM AND PROCESS FOR PRODUCING THE SAME

摘要

A film comprising a propylene/ alpha -olefin block copolymer which comprises at least one propylene resin block and at least one elastomer block consisting of a copolymer of propylene and an alpha -olefin having 2 to 12 (excluding 3) carbon atoms and in which the elastomer block accounts for 5 to 30 wt.% of the whole copolymer, the xylene-soluble components of the propylene/ alpha -olefin block copolymer have an intrinsic viscosity of 4.0 to 6.0 dl/g, and particles in the elastomer block satisfy the following: (1) the proportion of the particles having a machine-direction (MD) aspect ratio of 1 to 3 is 50 to 100%; (2) the proportion of the particles having an MD roundness of 1 to 1.2 is 60 to 95% and that of the particles having an MD roundness of 1.2 to 1.4 is 30% or lower; and (3) the proportion of the particles having an (MD) average particle diameter of 0.2 mu m or smaller is 45 to 80% and that of the particles having an MD average particle diameter of 0.4 to 1 mu m is 20 to 40%.