High barrier flexible packaging structure
The invention relates to a high oxygen barrier, multilayer flexible packaging structure having a vacuum metallized, biaxially oriented polypropylene (met-BOPP) or metallized polyester (met-PET) film substrate; a high barrier EVOH layer coextruded or laminated directly on the metal-containing layer; and optionally an adjacent layer of anhydride modified polyolefin such as blend of LDPE, or MDPE, or PP and maleic anhydride modified adhesive resin on the EVOH layer.
1. A laminate film, comprising, in this order:
a biaxially oriented polymer film substrate;
a metal-containing layer; and
an EVOH layer directly on the metal-containing layer, wherein said metal-containing layer has an optical density of about 1.5 to 5.0.
2. The laminate film of claim 1 , wherein the polymer film comprises a polymer selected from the group consisting of polyolefin, polyester, polyamide and combinations thereof.
3. The laminate film of claim 1 , wherein the polymer film comprises polyolefin.
4. The laminate film of claim 1 , wherein the metal-containing layer is a vacuum metallized layer.
5. The laminate film of claim 1 , further comprising an adjacent layer of anhydride modified polyolefin on the EVOH layer.
6. The laminate film of claim 5 , wherein the adjacent layer comprises a blend of a polyolefin resin and maleic anhydride modified adhesive resin, wherein the polyolefin resin is a low density polyethylene, a medium density polyethylene, polypropylene or combination thereof.
7. The laminate film of claim 5 , further comprising a second film layer on the adjacent layer, the second film layer comprising polypropylene, poly(ethylene terephthalate), or combination thereof.
8. The laminate film of claim 7 , wherein the second film layer is vacuum metallized or non-metallized.
9. The laminate film of claim 7 , further comprising a second barrier layer directly on the EVOH layer, the second barrier layer comprising a material selected from the group consisting of amorphous nylon and PVDC.
10. The laminate film of claim 1 , wherein the structure has a oxygen transmission rate of 0.5 cc/m 2 /day or less.
11. The laminate film of claim 1 , wherein the structure has a oxygen transmission rate of 0.35 cc/m 2 /day or less.
12. The laminate film of claim 1 , wherein the structure has a oxygen transmission rate of 0.2 cc/m 2 /day or less.
13. The laminate film of claim 1 , further comprising:
a heat sealable layer or winding layer comprising an antiblock component selected from the group consisting of amorphous silicas, aluminosilicates, sodium calcium aluminum silicate, a crosslinked silicone polymer and polymethylmethacrylate.
14. The laminate film of claim 13 , wherein said heat-sealable layer or winding layer has a thickness of about 0.5 to 5.0 μm.
15. The laminate film of claim 1 , wherein said substrate has a thickness of about 6 to 40 μm.
16. The laminate film of claim 1 , wherein said substrate is discharge-treated in an atmosphere of CO 2 and N 2 .
17. The laminate film of claim 1 , wherein the metal-containing layer comprises aluminum.
18. The laminate film of claim 1 , wherein the metal-containing layer is a metal layer, a metal oxide layer or combinations thereof.
19. The laminate film of claim 18 , wherein the metal oxide is aluminum oxide, silicon oxide or combinations thereof.
20. The laminate film of claim 1 , wherein the EVOH layer is a extruded EVOH layer or a laminated EVOH layer.
21. A laminate film, consisting of:
a biaxially oriented polymer film substrate;
a metal-containing layer on the substrate; and
an EVOH layer directly on the metal-containing layer, wherein said metal-containing layer has an optical density of about 1.5 to 5.0.