Reducing concentration of organic materials with substituted cyclodextrin compound in polyester packaging materials
Volatile organic compound or other materials are produced in the thermoplastic manufacture of thermoplastic polyester beverage containers. Such materials can be eluted into beverages such as carbonated beverages, sparkling or still water from the polyester. Such thermoplastic polyester resins can be manufactured with a substituted cyclodextrin material that can prevent the formation of, or react with, and absorb volatile by-products during the formation of thermoplastic preforms or containers from the thermoplastic pellet or chip. Further, as the preform is blown into a polyester container, the active materials of the invention prevent the generation of additional undesirable volatile materials. Lastly, the scavenger material can act as a barrier that prevents transport of materials from the exterior of the container into the container contents.
1. A thermoplastic polyester preform comprising a thermoplastic polyester and a substituted cyclodextrin compound, the preform comprising about 100 parts by weight to 1400 parts by weight of the substituted cyclodextrin compound per each one million parts of polyester resin, the substituted cyclodextrin having a degree of substitution of about 0.3 to 1.8; wherein the cyclodextrin is substantially free of any compound in the central pore of the cyclodextrin ring and the cyclodextrin is present in an effectivc amount to complex catalyst residue.
2. The preform of claim 1 wherein the polyester comprises at least 60% by weight polyethylene terephthalate units and up to 40% by weight other polymers.
3. The chip of claim 1 wherein the polyester comprises at least 60% by weight polyethylene naphthalate units and up to 40% by weight other polymers.
4. The chip of claim 1 wherein the polyester comprises a copolymer of polyethylene terephthalate/isophthalate and the cyclodextrin is a non-reducing carbohydrate.
5. The proform of claim 1 wherein the cyclodextrin compound has a substituent substantially on at least one —OH group on the −6 position of the glucose moiety in the cyclodextrin.
6. The preform of claim 5 wherein the cyclodextrin compound comprises a 6-O-Methyl ether.
7. The preform of claim 5 wherein the cyclodextrin compound comprises a 6-O Acetyl ester.
8. The preform of claim 5 wherein the cyclodextrin compound comprises a degree of substitution of about 0.5 to 1.2 in on amount of about 350 parts by weight to about 900 parts by weight of the cyclodextrin compound per each one million parts of polyester resin.
9. A thermoplastic polyester beverage container comprising a thermoplastic polyester and a substituted cyclodextrin compound, the container comprising about 100 parts by weight to 1400 parts by weight of the substituted cyclodextrin compound per each one million parts of polyester resin, the substituted cyclodextrin having a degree of substitution of about 0.5 to 1.8; wherein the cyclodextrin is substantially free of any compound in the central pore of the cyclodextrin ring and the cyclodextrin is present in an effective amount to complex catalyst residue.
10. The container of claim 9 wherein the polyester comprises at least 60% by weight polyethylene terephthalate units and up to 40% by weight other polymers.
11. The container of claim 9 wherein the polyester comprises at least 60% by weight polyethylene naphthalate units and up to 40% by weight other polymers.
12. The chip of claim 9 wherein the polyester comprises a copolymer of polyethylene terephthalate/isophthalate and the cyclodextrin is a non-reducing carbohydrate.
13. The container of claim 9 wherein the cyclodextrin compound has a substituent substantially on at least one —OH group on the −6 position of the glucose moiety in the cyclodextrin.
14. The container of claim 13 wherein the cyclodextrin compound comprises a 6-O-Methyl.
15. The container of claim 13 wherein the cyclodextrin compound comprises a 6-O Acetyl ester.
16. The container of claim 9 wherein the cyclodextrin compound comprises a degree of substitution of about 0.5 to 1.2 in an amount of about 350 parts by weight to about 900 parts by weight of the cyclodextrin compound per each one million parts of polyester resin.