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 resin, preferably an aromatic polyester resin such as polyethylene terephthalate (PET) and (ii) a polyamide material (e.g., MXD6). The blend optionally may further comprise (iii) 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 layer comprising the aforementioned blend; and one or more layers of a formable polymer composition. The present invention also provides methods of making such containers.
1. A multi-layered container, comprising:
a layer of a formable polymer; and
a blend layer comprising a blend of:
(i) between 10 and 60% by weight of a polyethylene terephthalate material,
(ii) between 45 and 60% by weight of a polyamide material,
(iii) 50 to 10,000 ppm of an oxygen scavenging material, and
wherein said blend layer comprises between about 3 and 6 percent of the total wall thickness of the container and wherein the percent polyamide material in the entire container is between 1.35 and 3.6% by weight.
2. The container of claim 1 , wherein the layer-to-layer lamination strength is sufficient such that a filled 473 ml bottle can withstand a drop of 46 cm without appreciable delamination.
3. The container of claim 1 , wherein the layer-to-layer lamination strength is sufficient such that a filled 473 ml bottle can withstand a drop of 1.2 m without appreciable delamination.
4. The container of claim 1 , wherein the blend comprises between 45 and 60% by weight PET.
5. The container of claim 1 , wherein the blend comprises between 30 and 60% by weight MXD6.
6. The container of claim 1 , wherein the blend comprises between 40 and 55% by weight of the polyamide material.
7. The container of claim 1 , wherein the container, is a three-layer (PET-Blend-PET), 295 ml beverage bottle haying a total wall thickness of 0.051 cm and a core layer of 5% of the total wall thickness, said container exhibits less than 15% loss of CO 2 over a 7.5 week period.
8. The container of claim 1 , wherein the container, is a three-layer (PET-Blend-PET), 295 ml beverage bottle having a total wall thickness of 0.051 cm and a core layer of 5% of the total wall thickness, said container exhibits less than 0.02 cc/pkg/day transmission of O 2 .
9. A preform for expansion into the container of claim 1 .
10. The container of claim 1 , wherein said blend layer comprises 50-1,000 ppm of an oxygen scavenging material.
11. The container of claim 1 , wherein the formable polymer comprises a formable polyester which is selected from the group consisting of PET, PC-PET, PETG, PEN and PBT.
12. The container of claim 11 , wherein the blend comprises between 20 and 60% by weight PET and wherein the polyamide comprises MXD6.
13. The container of claim 1 , 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 13 , wherein the oxygen scavenging material comprises cobalt.
15. The container of claim 13 , wherein the oxygen scavenging material comprises mixed metal nanoparticles.