| abstract |
The invention provides laminar polyolefin film materials having a base film layer comprising a blend of an olefin polymer and up to about 30% by weight of at least one very low density copolymer of ethylene and a C3 to C20 alpha olefin comonomer copolymerizable with ethylene, said base layer having a heat sealable film layer present on one or both surfaces thereof comprising a very low density copolymer of ethylene and a copolymerizable C5 to C12 alpha olefin comonomer. The ethylene copolymer constituents of the film are characterized as having a density in the range of about 0.88 g/cm3 to abut 0.915 g/cm3, a melt index in the range of about 0.5 dg/min to about 7.5 dg/min, a molecular weight distribution (Mw/Mn) of about 1.5 to about 3.5 and an essentially single melting point in the range of about 60 DEG C. to about 115 DEG C., measured as a DSC peak Tm. Films of this invention exhibit extremely good hot tack seal strength at temperatures in the range of from about 200 DEG to 290 DEG F. thereby rendering them extremely useful as packaging materials in high speed packaging operations. |