Lidding structure based on aromatic polyester film, coextruded with a sealable/peelable epdxy-containing thermoplastic polymer
AssigneeToray Plastics (America), Inc.
InventorStefanos L. Sakellarides
Life of this patent
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Abstract
A multi-layer film structure suitable as a sealable sheet used for closing foodstuff containers with a peelable seal. This multi-layer film comprises a polyester substrate layer and a heat-sealable layer. The heat-sealable layer is applied by coextrusion and contains an epoxy-containing thermoplastic polymer composition comprising residues of epoxy-containing monomers selected from glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, 3,4-epoxy-1-butene, and a mixture of any two or more of such monomers.
Claims15
A film comprising a heat-sealable surface layer and a polyester-containing core layer comprising polyethylene terephthalate, wherein the heat-sealable layer consists of an epoxy-containing thermoplastic polymer, wherein the film is a coextruded heat-sealable and peelable multilayer thermoplastic film, wherein a seal strength of the film at 325° F. (163° C.) with sealing done between the heat-sealable surface layer and crystalline polyethylene terephthalate is in a range from about 0.77 lbs/in (349 g/in) to about 1.22 lbs/in (553 g/in).
Dependencies are inferred from the claim text.