Heat shrinkable multi-layer film of hydrolyzed ethylene vinyl acetate and a cross-linked olefin polymer
AssigneeW. R. Grace & Co.
InventorsNorman D. Bornstein, Donald J. D'Entremont, Alan S. Weinberg, Henry G. Schirmer, Joseph Zu Sun
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Abstract
A heat shrinkable multi-layer packaging film having a layer of a hydrolyzed ethylene-vinyl acetate copolymer. Preferably, the film is formed by coextruding the hydrolyzed ethylene-vinyl acetate copolymer layer between two other polymeric layers, at least one of which is cross-linkable, and thereafter irradiating and orienting the multi-layer structure. The resulting film is heat shrinkable and has very low oxygen permeability.
Claims14
A multi-layer packaging film having low oxygen permeability comprising:
- a. two polymeric layers, at least one of which comprises an olefin polymer cross-linked to the equivalent of a dosage level in the range of 2 to 12 MR;
- and,
- b. a layer between said two polymeric layers which comprises a hydrolyzed ethylenevinyl acetate copolymer thereby defining a multi-layer film having at least three layers, said film having at least 10% heat shrinkage in both longitudinal and transverse directions at 195.degree. F.
A heat shrinkable multi-layer film having at least one layer which comprises a hydrolyzed ethylene vinyl acetate copolymer and a layer of crosslinked olefin polymer, said film having an oxygen transmission rate of less than 30.0 cc/m.sup.2, 24 hrs., atm. at 73.degree. F.
Dependencies are inferred from the claim text.