Unique copolymers comprising propylene, ethylene and/or one or more unsaturated comonomers are characterized as having: at least one, preferably more than one, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt%, (iii) a skewness index, S?ix?, greater than about -1.20, (iv) a DSC curve with a Tme that remains essentially the same and a Tmax that decreases as the amount of comonomer in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta catalyst. These polypropylene polymers are made using a nonmetallocene, metal-centered, heteroaryl ligand catalyst. These polymers can be blended with other polymers, and are useful in the manufacture of films, sheets, foams, fibers and molded articles.

Isotactic propylene copolymers, their preparation and use

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 C 3 to C 20 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 C 5 to C 12 alpha olefin comonomer. The ethylene copolymer constituents of the film are characterized as having a density in the range of about 0.88 g/cm 3 to abut 0.915 g/cm 3 , a melt index in the range of about 0.5 dg/min to about 7.5 dg/min, a molecular weight distribution (M w /M n ) of about 1.5 to about 3.5 and an essentially single melting point in the range of about 60° C. to about 115° C., measured as a DSC peak T m . Films of this invention exhibit extremely good hot tack seal strength at temperatures in the range of from about 200° to 290° F. thereby rendering them extremely useful as packaging materials in high speed packaging operations.

Heat sealable polyolefin films containing very low density ethylene copolymers.

The present invention relates to plasticized polyolefin compositions comprising a polyolefin and a non-functionalized hydrocarbon plasticizer.

Plasticized polyolefin compositions

An ethylene polymer extrusion composition having high draw down and substantially reduced neck-in, a process for making such a composition and a process of using such a composition to prepare extrusion coatings, extrusion profiles and extrusion cast films are disclosed. The ethylene polymer extrusion composition is made of 75-95 weight percent of at least one ethylene α-olefin interpolymer and 5-25 weight percent of at least one high pressure ethylene polymer characterized as having high melt strength and a broad, bimodal molecular weight distribution. In profiles, coatings or films, the composition can be used as sealant, adhesive or abuse resistance layers.

Extrusion compositions having high drawdown and substantially reduced neck-in

Improved thermoplastic polymer blend compositions comprising an isotactic polypropylene component and an alpha-olefin and propylene copolymer component, said copolymer comprising crystallizable alpha-olefin sequences. In a preferred embodiment, improved thermoplastic polymer blends are provided comprising from about 35% to about 85% isotactic polypropylene and from about 30% to about 70% of an ethylene and propylene copolymer, wherein said copolymer comprises isotactically crystallizable propylene sequences and is predominately propylene. The resultant blends manifest unexpected compatibility characteristics, increased tensile strength, and improved process characteristics, e.g., a single melting point.

Propylene olefin copolymers

Heat sealable compositions suitable for film and film structures comprise: (a) from 30 to 70 weight percent of a low melting polymer comprising an ethylene based copolymer having a density of from 0.88 g/cm3 to 0.915 g/cm3, a melt index of from 1.5 dg/min to 7.5 dg/min, a molecular weight distribution no greater than 3.5, and a composition distribution breath index greater than 70 percent; and, (b), being different from (a), from 70 to 30 weight percent of a propylene based polymer having from 88 mole percent to 100 mole percent propylene and from 12 mole percent to 0 mole percent of an alpha-olefin other than propylene.

Michael Chia-Chao Chen

Papers

Heat sealable blend of very low density polyethylene or plastomer with polypropylene based polymers and heat sealable film and articles made thereof