摘要 |
<p>The invention is directed to an oriented multi-layer film which comprises a voided layer and at least one non-voided layer on at least one surface of the voided layer. In one embodiment, the voided layer comprises a Ziegler-Natta or metallocene-catalyzed substantially isotactic propylene polymer in a polymer matrix with a cavitation initiator. In a second embodiment, the non-voided layer comprises a Ziegler-Natta or metallocene-catalyzed substantially isotactic polypropylene polymer. In a third embodiment, both the voided core layer and at least one non-voided layer comprise a metallocene-catalyzed substantially isotactic polypropylene polymer.</p> |