Multilayered package with barrier properties
View Patent ↗The present invention provides compositions useful as a barrier layer in, for example, packaging products. The compositions generally comprise a blend of (i) a polyester material, preferably an aromatic polyester resin such as polyethylene terephthalate (PET) and (ii) a vinyl alcohol material. The blend optionally may further comprise (iii) a polyolefin material (preferably a functionalized polyolefin material, e.g., a BYNEL material); and/or (iv) a polyamide material (preferably an amorphous polyamide material, e.g., a GRIVORY material), that optionally further comprises an oxygen scavenging material. The present invention also provides containers (e.g., containers formed by expansion of preforms) having a multilayered body-forming portion including: a core layer comprising the aforementioned blend, and inner and outer layers of a formable polymer composition. The present invention also provides methods of making such containers.
1. A multilayered container, comprising:
a layer of a formable polymer; and
a layer of a composition comprising a blend of (i) between 30 and 70% by weight of a polyester material, (ii) between 25 to 54% by weight of a vinyl alcohol material, and (iii) between 0.5 and 25% by weight of a functionalized polyolefin material.
2. The container of claim 1 , wherein the blend comprises between 25 and 50% by weight of the vinyl alcohol material.
3. The container of claim 1 , wherein the polyester material is polyethylene terephthalate.
4. The container of claim 1 , wherein the vinyl alcohol material comprises ethylene vinyl alcohol copolymer.
5. The container of claim 4 , wherein the ethylene vinyl alcohol copolymer comprises between 25 and 50 mol % ethylene content.
6. The container of claim 1 , wherein the vinyl alcohol material has a melt index between about 20 to 1.
7. The container of claim 1 , wherein the polyester material is selected from the group consisting of PET, PC-PET, PETG, PEN, and PBT.
8. The container of claim 1 , wherein the polyester material is PET having a viscosity average molecular weight between 36,000 and 103,000 Dalton.
9. The container of claim 1 , wherein the container consists of a first layer of a formable polymer, a core layer of the blend, and a second layer of the formable polymer, wherein the formable polymer is PET, and wherein the container has a liquid capacity of 295 ml, a total wall thickness of 0.051 cm and the core layer is 5% of the total wall thickness of the container, and wherein the container exhibits less than 15% loss of CO 2 over a 7.5 week period.
10. The container of claim 1 , wherein the container consists of a first layer of a formable polymer, a core layer of the blend, and a second layer of the formable polymer, wherein the formable polymer is PET, and wherein the container has a liquid capacity of 295 ml, a total wall thickness of 0.051 cm and the core layer is 5% of the total wall thickness of the container, and wherein the container exhibits less than 0.02 cc/pkg/day transmission of O 2 .
11. The container of claim 1 , wherein the blend further comprises an amorphous polyamide.
12. The container or claim 11 , further comprising an oxygen scavenging material.
13. The container of claim 12 , wherein the oxygen scavenging material forms active metal complexes having capacity to bond with oxygen for conferring high oxygen barrier properties to the composition.
14. The container of claim 12 , wherein the oxygen scavenging material comprises cobalt.
15. The container of claim 12 , wherein the oxygen scavenging material comprises mixed metal nanoparticles.
16. The container of claim 12 , wherein the polyamide is a copolyamide comprising linear aliphatic units and aromatic components.
17. A multilayered container, comprising:
a layer of formable polymer; and
a layer of a composition comprising a blend of (i) between 30 and 70% by weight of a polyester material, (ii) between 25 and 54% by weight of a vinyl alcohol material, and (iii) between 1 and 10% by weight of a functionalized polyolefin material.
18. The container of claim 17 , wherein the functionalized polyolefin material comprises maleic anhydride functionality.
19. The container of claim 17 , wherein the blend further comprises an amorphous polyamide.
20. The container of claim 19 , wherein the polyamide is a copolyamide comprising linear aliphatic units and aromatic components.
21. The container of claim 17 , wherein the blend comprises between 25 and 50% by weight of the vinyl alcohol material.
22. The container of claim 17 , wherein the vinyl alcohol material comprises ethylene vinyl alcohol copolymer.
23. A container having a hollow plastic multilayer body, including:
a core layer comprising the composition of claim 1 ; and
inner and outer layers of a formable polymer.
24. The container of claim 23 , wherein the core layer has a thickness of between about 2 and 8 percent of the total wall thickness.
25. The container of claim 24 , wherein the inner and outer layers comprise virgin PET and further comprising inner and outer intermediate layers of a polymer selected form the group consisting of EVOH, PEN, PVDC, nylon 6, MD-6, LCP, amorphous nylon, PAN, SAN, and AMOSORB and PC-PET.
26. A preform for expansion into a hollow plastic container body, the perform having a multilayered body-forming portion including:
a core layer comprising the composition of claim 1 ; and
inner and outer layers of a formable polymer composition.
27. The preform of claim 26 , wherein the formable polymer composition comprises polyethylene terephthalate.
28. The preform of claim 26 , wherein the preform has been expanded into a hollow plastic container body.
29. The expanded preform of claim 28 , wherein the core layer has an average thickness of between 1 and 10 percent of the overall thickness of the body.