Abstract: A coextruded biaxially oriented polyolefin packaging film has a cold seal release layer, a core layer, and a cold seal receptive skin layer. The release layer is made of (A) about 10% to about 60% by weight ethylene-butylene random copolymer containing between 0% and about 6.0% by weight ethylene and between about 94% and 100% by weight butylene; (B) a blend of two polymers selected from the group consisting of polyethylene ionomers, syndiotactic homopolymer polypropylene, conventional polyethylenes having densities of between 0.91 and 0.965 gm/cm.sup.3, and metallocene-catalyzed polyethylene plastomers; and optionally (C) a non-migratory slip agent present in an amount sufficient to decrease the coefficient of friction of the release layer. Alternatively, the release layer may be made of a two-component blend of the ethylene-butylene random copolymer and high density polyethylene.

Abstract: An aroma barrier layer for a packaging film is provided which contains a homogeneous blend of an amorphous nylon component and a maleic anhydride-modified polyolefin component. The maleic-anhydride content in the polyolefin component and the relative amounts of the two components are selected such that the two components are compatible with one another and the barrier layer constitutes a continuous homogeneous layer substantially free of any platelet formation and distinct layers. Compositions of the homogeneous blend and packaging films including the barrier layer are also provided.

Abstract: The invention presents a new use for modified polypropylene films, wherein the films are cold sealable for heat sensitive packaging operations. The films comprise in the following order: a cold seal cohesive layer, a core layer, and a cold seal release layer comprising a mixture of about 1 to 80% by weight butene-propylene copolymer and about 99 to 20% by weight butylene-ethylene copolymer.

Abstract: A coextruded biaxially oriented polyolefin packaging film has a cold seal release layer, a core layer, and a cold seal receptive skin layer. The cold seal release layer is fabricated of about 1% to about 80% by weight polyolefin polymer selected from isotactic homopolymer polypropylene, syndiotactic homopolymer polypropylene, homopolymer polyethylene, ethylene-alpha-olefin copolymers made by metallocene catalysis, e.g. ethylene-butylene (plastomers), blends of plastomers with syndiotactic homopolymer polypropylene, blends of syndiotactic homopolymer polypropylene with ethylene-propylene random copolymer, and mixtures thereof. In addition, the release layer contains from about 20% to about 99% by weight polybutylene-polyethylene copolymer containing between about 0.5% and about 6.0% by weight ethylene and between about 94% and about 99.5% by weight butylene, and optionally an effective amount of non-migratory slip agent.

Abstract: The invention presents a new use for modified polypropylene films, wherein the films are cold sealable for heat sensitive packaging operations. In a preferred embodiment, the film comprises a laminate having at least one cold seal release layer and a cold seal receptive layer such that when the release layer is adjacent a cold seal cohesive on the cold seal receptive layer, the release layer and the cold seal receptive layer exhibit remarkably low adhesion. Typical cold seal materials include natural and synthetic rubber latex cohesives.

Abstract: An oriented polymeric alpha-olefin film having: an isotactic polypropylene homopolymer core; a cold seal release skin layer adherent to one side of the core; and a surface treated cold seal receptive layer or such treated layer with a cold seal cohesive composition over the surface treatment of said layer on the other side of the core. The cold seal release skin layer comprises a slip agent and a blend of two polymers, namely, an ethylene-propylene random copolymer containing about 2% to 8% of ethylene in such copolymer and an ethylene-butylene copolymer containing about 0.5% to 6% of ethylene in such copolymer. The cold seal receptive layer is of an ethylene-propylene random copolymer containing about 2 to 8% of ethylene.

Abstract: There is disclosed an oriented, polyolefin film having a white-opaque cold seal receptive skin layer on one side of a core layer and a vacuum deposited metal layer on the other side of the core layer. The cold seal receptive polyolefin layer contains: (a) a slip agent in an amount sufficient to provide not more than about an 0.4 coefficient of friction to the surface of such layer; and (b) from about 10 to 40% by weight of titanium dioxide. The core layer is substantially free of opacifying filler and/or opacifying voids. The other side of the film is metallized to an optical density of at least 1.5 whereby the white pigment in the sealing layer in cooperation with the metallization gives a strong white-opaque appearance to the cold seal receptive layer.

Abstract: There is disclosed an oriented, polyolefin film having a white-opaque skin layer on one side of a core layer and a vacuum deposited metal layer on the other side of the core layer. The sealable polyolefin layer contains: (a) a slip agent in an amount sufficient to provide not more than about an 0.4 coefficient of friction to the surface of such layer; and (b) from about 10 to 40% by weight of titanium dioxide. The core layer is substantially free of opacifying filler and/or opacifying voids. The other side of the film is metallized to an optical density of at least 1.5 whereby the white pigment in the sealing layer in cooperation with the metallization gives a strong white-opaque appearance to the sealing layer.