PVOH barrier performance on substrates
Disclosed are coated substrates and methods for producing coated substrates. At least one surface of the substrates is coated with a polyvinyl alcohol polymer to render the substrates resistant to oil and grease. The polyvinyl alcohol polymer is coated at levels of a least 7 g/m 2 , based upon area of the coated surface of the substrate. Alternatively, the coating concentration is at least 5 wt. % of the weight of the substrate. The coatings may be applied by curtain coating or means and comprise at least one layer of a polyvinyl alcohol solution.
1 . A coated substrate comprising:
(i) a substrate having a first and second surface;
(ii) a coating on the first surface of the substrate comprising at least about 7 g/m 2 of a polyvinyl alcohol polymer, based upon the surface area of the first surface of the substrate.
2 . The coated substrate of claim 1 wherein the coating is a curtain coated coating.
3 . The coated substrate of claim 2 wherein the substrate is comprised of at least one layer a material selected from the group consisting of paper, paperboard, plastic, fiberglass, canvas, and textile materials.
4 . The coated substrate of claim 3 wherein the first surface of the substrate exhibits a resistance to vegetable oil of at least 240 minutes.
5 . The coated substrate of claim 3 wherein the coating on the first surface of the substrate comprises about 10 g/m 2 to about 15 g/m2 of a polyvinyl alcohol polymer, based upon the surface area of the first surface of the substrate.
6 . The coated substrate of claim 5 wherein the substrate is comprised of a material selected from paper and paperboard.
7 . The coated substrate of claim 6 wherein the first surface of the substrate exhibits a kit test value of at least 4.
8 . The coated substrate of claim 7 wherein the substrate is paper.
9 . The coated substrate of claim 8 wherein the polyvinyl alcohol polymer selected from the group consisting of a homopolymer, a copolymer incorporating at least one co-monomer selected from ethylene, methyl acrylate, a carboxylic acid, an alkyl acid vinyl ester, an acryl amide, and blends thereof.
10 . The coated substrate of claim 9 wherein the first surface of the substrate exhibits a turpentine crease test value of at least 1800.
11 . The coated substrate of claim 10 wherein the coating is comprised of a polyvinyl alcohol polymer having a degree of hydrolysis % of 87.0 to 89.0 and a viscosity at 4.0% solids and 20° C. of 5.2 to 6.2.
12 . The coated substrate of claim 11 wherein the first and second surface of the substrate comprising a coating comprising from about 10 g/m 2 to about 15 g/m2 of a polyvinyl alcohol polymer, based upon the surface area of the first surface and the second surface of the substrate.
13 . A coated substrate comprising:
(iii) a substrate having a first and second surface;
(iv) a curtain coated coating on the first surface of the substrate comprising at least 5 wt. %, of the weight of the substrate, of a polyvinyl alcohol polymer.
14 . A method of producing a coated substrate comprising coating a substrate having a first and second surface with a polyvinyl alcohol polymer at a concentration of at least about 7 g/m 2 on the first surface of the substrate, based upon the surface area of the first surface of the substrate.
15 . The method of claim 14 wherein the step of coating the first surface of the substrate with a polyvinyl alcohol polymer is carried out by the application of an aqueous solution comprising a polyvinyl alcohol polymer to the first surface of the substrate with a curtain coater.
16 . The method of claim 15 wherein the substrate is comprised of at least one layer a material selected from the group consisting of paper, paperboard, plastic, fiberglass, canvas, and textile materials.
17 . The method of claim 16 wherein the aqueous polyvinyl alcohol solution has a solids content of about 7.0 wt. % to about 15.0 wt. % solids, based upon the total weight of the aqueous polyvinyl alcohol solution and the polyvinyl alcohol polymer has a degree of hydrolysis % of 87.0 to 89.0 and a viscosity at 4.0% solids and 20° C. of 5.2 to 6.2
18 . The method of claim 17 wherein the aqueous polyvinyl alcohol polymer solution is applied to the first surface of the substrate at a concentration of about 10.0 g/m 2 to about 15.0 g/m 2 of the first surface of the substrate.
19 . The method of claim 18 wherein a coating of a polyvinyl alcohol polymer is applied to the first and second surfaces of the substrate.
20 . A method of producing a coated substrate comprising curtain coating a substrate having a first and second surface with a polyvinyl alcohol polymer at a concentration of at least 5 wt. % of the weight of the substrate.