Packaging material
Packaging material formed from a substrate and three coating layers or in some instances at least three coating layers, each coating including an aqueous polymeric solution or dispersion dried to form a continuous film such that the packaging material is provided with tailored performance attributes including desired moisture vapor transmission rates, oxygen permeation rates, oil and grease resistance peel strength. The materials forming the packaging material may be compostable or biodegradable.
1. A packaging material consisting essentially of a substrate and three aqueous coating layers, with the substrate having a first side and a second side, wherein one of the first and second side exhibits a Sheffield Roughness in a range between about 40 ml/min to about 400 ml/min;
the three aqueous coating layers including
a. a first coating applied to one of the first or second side of the substrate to form a first coating layer, the first coating comprising an amount of an acrylic latex dispersion to provide water vapor barrier properties and oil and grease resistance, a second coating applied to the first coating layer to form a second coating layer and comprising an amount of a polyvinyl alcohol, ethyl vinyl alcohol, or combinations thereof to provide oxygen barrier properties, and a third coating layer applied to the second coating layer and comprising a latex dispersion, or
b. a first coating applied to the first side of the substrate to form a first coating layer, the first coating comprising an amount of a polyvinyl alcohol, ethyl vinyl alcohol, or combinations thereof to provide oxygen barrier properties, a second coating applied to the first coating layer to form a second coating layer and comprising an amount of an acrylic latex dispersion to provide water vapor barrier properties and oil and grease resistance, and a third coating applied to the second side of the substrate, the third coating comprising an amount of an acrylic latex dispersion to provide water vapor barrier properties and oil and grease resistance;
wherein the packaging material is biodegradable or compostable, has an oxygen transmission rate (OTR) between about 1 cc/m 2 /day to about 30 cc/m 2 /day, a water vapor transmission rate (WVTR) between about 1 g/m 2 /day to about 75 g/m 2 /day, and an oil and grease resistance to provide less than about 10% staining.
2. The packaging material of claim 1 wherein the substrate comprises paper having a basis weight between about 10 lbs./3000 ft 2 and about 50 lbs./3000 ft 2 .
3. The packaging material of claim 2 wherein the paper has been pretreated with a size press coating using a sizing agent selected from the group consisting of alkenyl ketene dimer, alkenyl succinic anhydride, alkyl ketene dimer, styrene acrylic emulsion, styrene maleic anhydride, wax emulsions, and mixtures thereof.
4. The packaging material of claim 2 wherein the paper has been pretreated with size press coating containing talc filler.
5. The packaging material of claim 1 wherein each coating layer is applied in an amount to provide a total coating basis weight from about 5 g/m 2 to about 50 g/m 2 .
6. The packaging material of claim 1 wherein at least the third coating layer is an aqueous emulsion that includes one or more acrylic polymers and one or more heat sealable waxes.