Anti-blocking coatings for PVdc-coated substrates
View Patent ↗A barrier composite having reduced blocking is disclosed. The composite may include a substrate, a barrier layer formed from polyvinylidene chloride disposed on the substrate, and an anti-blocking layer disposed on the barrier layer. The anti-blocking layer may be formed from polyvinyl alcohol, and optionally, colloidal silica, wax, or a combination thereof. Alternatively, the anti-blocking layer may be formed from a polymeric carrier material, colloidal silica, and a wax. Methods for forming such composites and for forming a roll of such composites are also disclosed.
1. A barrier composite comprising:
a) a substrate:
b) a barrier layer comprising polyvinylidene chloride disposed on the substrate; and
c) an outermost layer comprising an anti-blocking layer disposed on the barrier layer, wherein the anti-blocking layer consists essentially of polyvinyl alcohol.
2. The composite of claim 1 , wherein the ratio of the weight of the anti-blocking layer to the weight of the barrier layer is from about 0.1 to about 0.4 on a dry/dry per unit area basis.
3. The composite of claim 1 , wherein the ratio of the weight of the anti-blocking layer to the weight of the barrier layer is from about 0.2 to about 0.3 on a dry/dry per unit area basis.
4. The composite of claim 1 , wherein the ratio of the weight of the anti-blocking layer to the weight of the barrier layer is about 0.25 on a dry/dry per unit area basis.
5. The composite of claim 1 , wherein the ratio of the weight of the barrier layer to the weight of the substrate is from about 0.1 to about 0.4 on a dry/dry per unit area basis.
6. The composite of claim 1 , wherein the ratio of the weight of the barrier layer to the weight of the substrate is from about 0.2 to about 0.4 on a dry/dry per unit area basis.
7. The composite of claim 1 , wherein the ratio of the weight of the barrier layer to the weight of the substrate is about 0.25 on a dry/dry per unit area basis.
8. The composite of claim 1 , wherein the substrate comprises a coated paper, an uncoated paper, a polymer film, or any combination thereof.
9. The composite of claim 1 , wherein the substrate comprises polyethylene terephthalate film.
10. The composite of claim 9 , wherein the polyethylene terephthalate film has a thickness of about 0.0005 in.