Imperial Chemical Industries Limited

Robert C Lansbury

Thomas G Heggs

Douglas L Mitchell

Martin E Howden

A multiple-layer film comprises an oriented propylene polymer substrate with a heat-sealable layer comprising an ethylene polymer of density not exceeding 0.95 g cm.sup.-3 and containing a spherical, non-agglomerating additive of particle size not exceeding 5.0 .mu.m. Such films offer improved blocking- and abrasion-resistance, and are of utility in high-speed packaging operations.

Multiple-layer polyolefin films

A multiple-layer heat-sealable film comprising a polyolefin substrate layer having on at least one surface thereof a heat-sealable layer comprising a random copolymer of propylene with from greater than 4 to 10 wt% of ethylene, the copolymer having a degree of randomness of greater than 2.5.

Composite heat-sealable films

The invention provides a multiple-layer metallized film comprising a substrate layer of a polymer or copolymer of an alpha-olefin, the molecule of which contains from 2 to 6 carbon atoms, having on at least one surface thereof an adherent layer comprising a random copolymer of ethylene with from 0.5 to 15 wt % of a 3 to 6 carbon alpha-mono-olefin, and a metallic layer on the surface of the adherent layer remote from the substrate. Improved adhesion between the metallized and substrate layers is thereby achieved, and the multi-layer film is suitable for packaging a variety of edible products.

Metallized films

A film-forming composition comprising a copolymer of propylene with an alpha-olefin containing from 4 to 10 carbon atoms, the copolymer containing from 80 to 95% by weight of propylene, and from 25 to 90% by weight of the composition of a second homo- or co-polymer of a similarly defined alpha-olefin. The composition is particularly suitable for the production of heat-sealable, multiple-layer films having a polypropylene core.

Film-forming composition

A multiple-layer film having a substrate layer of high density polyethylene or a propylene homo- or co-polymer, and, on at least one surface of the substrate, a heat-sealable layer of a propylene co-polymer containing from 80 to 95% of propylene, the balance being a C.sub.4 to C.sub.10 olefin. The substrate and surface layers exhibit a monoclinic crystalline structure.

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St. Albans, United Kingdom

Robert C Lansbury