Patent ID: 8211533

Claim:
A flowable material packaging film comprising, at least a resin blend of: (a) from about 33 wt % to about 80 wt % of at least one ethylene-C 4 to C 10 -α-olefin interpolymer, having a melt index of from 0.4 to 1.5 g/10 min (190° C., 2.15 kg), and a density of from 0.900 to 0.916 g/cm 3 ; and (b) from about 67 wt % to about 20 wt % of at least one heterogeneous interpolymer of propylene: (i) with ethylene, or (ii) with ethylene and butene, said at least one heterogeneous interpolymer of propylene comprising from about 71 mol % to about 86 mol % propylene, and from about 29 mol % to about 14 mol % ethylene or ethylene and butene; wherein said at least one heterogeneous interpolymer of propylene has an overall weight average molecular weight (M W ) of at least about 400,000, a xylene soluble phase of not less than 30 wt %, with the xylene soluble phase having a M W of at least about 275,000; wherein said at least one heterogeneous interpolymer of polypropylene has a density of from 0.875 to 0.91 g/cm 3 ; wherein said flowable material packaging film has a Hot-Tack Initiation Temperature in the range of from about 100° C. to about 140° C., and a Hot-Tack Strength of not more than about 5 N/inch in the temperature range of about 100° C. to about 150° C., when fabricated at a thickness of about 50 μm and tested using a JB Instrument Hot Tack Tester set at a 0.5 s dwell, 0.2 s delay time, 40 psi seal bar pressure and 250 mm/s peel rate; and wherein said flowable material packaging film has a flex crack resistance such that it develops 5 or less pinholes per 300 cm 2 in 10,000 cycles of Gelbo Flex testing as measured according to ASTM F392.