Composition comprising ethylene copolymers and polyolefin
View Patent ↗Disclosed are compositions of ethylene/(meth)acrylate copolymers, polyolefins (e.g., polyethylene and polypropylene), optional tackifier resins and optional fillers that provide very strong, tight hermetic heat seals yet are easily peelable. These compositions are useful as an adhesive layer in multilayer structures that are useful as packaging lidding films. Also disclosed are packages that comprise these multilayer structures.
1. A multilayer structure comprising at least one adhesive layer produced from a composition, at least one second layer, and at least one third layer wherein
the adhesive layer forms a peelable seal characterized by interfacial peel failure to the third layer;
the composition consists essentially of (a) from about 10 to about 80 weight % of a combination of an ethylene/alkyl acrylate copolymer and an ionomer of either ethylene/acrylic acid copolymer or ethylene/methacrylic acid copolymer; (b) from about 5 to about 60 weight % of a polyolefin consisting essentially of high density polyethylene, linear low density polyethylene, very low density polyethylene, ultra low density polyethylene, low density polyethylene, or combinations of two or more thereof; (c) from 0 to about 35 weight % of at least one tackifying resin; and (d) from 0 to about 35 weight % of filler;
the second layer comprises or is produced from foil, paper, polyester, polyamide, polyolefin, polyethylene vinyl alcohol, polyethylene vinyl acetate, ethylene/(meth)acrylic acid copolymer, ionomer of ethylene/(meth)acrylic acid copolymer, polyvinyl chloride, polyvinylidene chloride, or anhydride-modified polyolefin; and
the third layer comprises or is produced from polypropylene, polystyrene or high-impact polystyrene, expanded polystyrene, acrylic homopolymer, acrylic copolymer, polycarbonate, polysulfone, amorphous polyethylene terephthalate, crystalline polyethylene terephthalate, PVC, polychlorotrifluoroethylene, polyacrylonitrile homopolymer, polyacrylonitrile copolymer, polyacetal, or polyacetal copolymer.
2. The multilayer structure of claim 1 wherein the adhesive layer provides a heat sealable film layer and with the second layer comprises a lidding material for a container comprising the third layer.
3. The multilayer structure of claim 1 wherein the third layer comprises polypropylene, polystyrene, high-impact polystyrene, amorphous polyethylene terephthalate, crystalline polyethylene terephthalate or PVC.
4. The multilayer structure of claim 3 wherein the third layer comprises polypropylene, polystyrene, high-impact polystyrene or PVC.
5. A package or container comprising or produced from a multilayer structure as recited in claim 1 .
6. The package or container of claim 5 wherein the third layer comprises polypropylene, polystyrene, high-impact polystyrene, amorphous polyethylene terephthalate, crystalline polyethylene terephthalate, or PVC.
7. The package or container of claim 6 being a blister package, a pouch, a molded, a pressed or thermoformed container and the third layer comprises polypropylene, polystyrene, high-impact polystyrene, or PVC.