Patent ID: 7094856

Claim:
In a process for producing a polyolefin film comprising: providing a primary polymer component comprising an isotactic propylene homopolymer produced by the polymerization of propylene in the presence of a Ziegler-Natta catalyst; providing a secondary polymer component selected from the group consisting of: a Ziegler-Natta polymerized ethylene-propylene random copolymer containing no more than 0.5 wt. % ethylene and having a xylene solubles content of at least 2 wt. % content; and a metallocene-polymerized ethylene-propylene random copolymer produced by the copolymerization of propylene and ethylene in the presence of a metallocene polymerization catalyst; mixing said primary and secondary polymer components together to provide a mixture of said primary and secondary polymer components, wherein the secondary polymer component is present in an amount of from 5 to 25 wt. % when the secondary polymer component is the Ziegler-Natta polymerized ethylene-propylene random copolymer and wherein the secondary polymer component is present in an amount of 5 wt. % or less when the secondary polymer component is the metallocene-polymerized ethylene-propylene random copolymer; and forming a biaxially oriented film layer of said polymer mixture by stretching said polymer mixture in longitudinal and transverse directions.