Dienophile additives to polyvinylidene chloride copolymers
AssigneePechiney Emballage Flexible Eruope
InventorsRoger Kaas, Chad Mueller
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Abstract
A flexible film for packaging articles such as food is provided. The film comprises a layer of polyvinylidene (“PVdC”) homopolymer, polyvinylidene and methyl acrylate (“PVdC-MA”) copolymer or other polyvinylidene chloride copolymer. A dienophile such as, for example, ethyl trans-cinnamate, methyl trans-cinnamate, dibutyl maleate, dimethyl maleate or maleic anhydride is blended with the PVdC polymer or PVdC-MA copolymer to reduce yellowing of the film caused by degradation of the PVdC or PVdC-MA through heat or electron beam irradiation. Preferably a range of about 0.05% and about 5% by weight of the dienophile is added to the PVdC or PVdC-MA.
Claims23
A flexible film comprising:
- a plurality of layers wherein a first layer comprises polyvinylidene chloride;
- and
- a dienophile additive in the first layer of polyvinylidene chloride.
A flexible film package for a food article comprising:
- a flexible film having a plurality of layers contained therein wherein a first layer comprises polyvinylidene chloride and a dienophile additive wherein the dienophile additive is selected from the group consisting of a cinnamate, a maleate and maleic anhydride.
A method of making a flexible film, the method comprising the steps of:
- providing polyvinylidene chloride;
- blending a dienophile with the polyvinylidene chloride to produce a polyvinylidene chloride/dienophile blend wherein the dienophile is selected from the group consisting of a cinnamate, a maleate and maleic anhydride;
- and
- extruding the polyvinylidenechloride/dienophile blend through a die to make a film.
Dependencies are inferred from the claim text.