Patent ID: 8617717

Claim:
A heat sealable film structure comprising: (a) an unoriented or uniaxially oriented base layer comprising a metallocene-catalyzed isotactic polypropylene homopolymer having an isotacticity of from about 80 to 99%, a melting point from about 155Â° C. to about 165Â° C., and a melt flow rate (2.16 kg @ 230Â° C., ASTM D-1238) of from 0.5 g/10 min to about 15 g/10 min; and (b) a heat-seal layer having: a seal-initiation temperature â‰¦130Â° C.; and comprising from 80 wt % to 90 wt % of a first polymer component (FPC) and 10 wt % to 20 wt % of a second polymer component (SPC), based on the total weight of FPC and SPC, wherein: (i) the FPC comprises a polypropylene copolymer with 2 to 5 wt % comonomer and has a heat of fusion >75 J/g and a melting point â‰§105Â° C.; and (ii) the SPC comprises from about 75 wt % to about 95 wt % propylene and from about 8 wt % to about 16 wt % ethylene, the SPC having a melting point of about 25Â° C. to about 65Â° C. and a heat of fusion <75 J/g, wherein 50 to 99 percent of the heat sealable film thickness is the base layer, and wherein the base layer further comprises a slip agent, and the heat seal layer further comprises a slip agent and an anti-blocking agent.