Increasing the gas transmission rate of a film comprising fullerenes

• US 20070042089A1
• Filed: 08/19/2005
• Published: 02/22/2007
• Est. Priority Date: 08/19/2005
• Status: Active Grant

• Current Assignee: Cryovac Incorporated (Sealed Air)
• Original Assignee: Cryovac Incorporated (Sealed Air)
• Inventors: Grah, Michael
• Granted Patent: US 7,678,841 B2
• Time in Patent Office: Days
• US Class Current: 426/106
• CPC Class Codes: B29C 71/04 by wave energy or particle radiation , e.g. for curing or vulcanising preformed articles during moulding, e.g. in a mould B29C35/08
• CPC Class Codes: B29L 2007/008 Wide strips, e.g. films, webs
• CPC Class Codes: B32B 2250/02 2 layers
• CPC Class Codes: B32B 2250/24 All layers being polymeric
• CPC Class Codes: B32B 2264/108 Carbon, e.g. graphite particles
• CPC Class Codes: B32B 2307/406 Bright, glossy, shiny surface
• CPC Class Codes: B32B 2307/412 Transparent
• CPC Class Codes: B32B 2307/7244 Oxygen barrier
• CPC Class Codes: B32B 2307/736 Shrinkable
• CPC Class Codes: B32B 2439/70 Food packaging
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 3/085 spaced apart pieces on the surface of a layer

Abstract

A method of increasing the gas transmission rate of a packaging film comprises providing a packaging film that comprises at least about 0.001 weight % of fullerene material selected from spherical fullerenes, bowl-shaped fullerenes, multi-walled carbon nanotubes, carbon nanocones, and carbon nano-onions. The packaging film is exposed to an amount of radiation energy effective to increase the oxygen transmission rate of the packaging film by at least about 100 cc (STP)/m2. day (1 atm, 0% RH, 23° C.).

Claims

1. A method of increasing the gas transmission rate of a packaging film comprising the steps of:

providing a packaging film comprising at least about 0.001 weight %, based on the weight of the film, of fullerene material selected from one or more of spherical fullerenes, bowl-shaped fullerenes, multi-walled carbon nanotubes, carbon nanocones, and carbon nano-onions; and

exposing the packaging film to an amount of radiation energy effective to increase the oxygen transmission rate of the packaging film by at least about 100 cubic centimeters (at standard temperature and pressure) per square meter per day per 1 atmosphere of oxygen pressure differential measured at 0% relative humidity and 23°

C.

2. The method of claim 1 wherein the radiation energy amount comprises a surface dose of non-ionizing radiation of at least about 0.01 mJ/cm2:

that is delivered within a duration of at most about 30 seconds.

3. The method of claim 1 wherein the radiation energy amount comprises a surface dose of non-ionizing radiation of at least about 1 mJ/cm2 that is delivered within a duration of at most about 10 seconds.

4. The method of claim 1 wherein the radiation exposure step comprises a radiation intensity of non-ionizing radiation at the surface of the packaging film of at least about 10 mW/cm2.

5. The method of claim 1 wherein the radiation exposure step comprises a radiation intensity of non-ionizing radiation at the surface of the packaging film of at least about 50 mW/cm2.

6. The method of claim 1 wherein the radiation exposure step comprises a radiation intensity of non-ionizing radiation at the surface of the packaging film of at least about 100 mW/cm2.

7. The method of claim 1 wherein the radiation exposure step comprises a radiation intensity of non-ionizing radiation at the surface of the packaging film of at least about 500 mW/cm2.

8. The method of claim 1 wherein the radiation energy amount comprises an absorbed dose of ionizing radiation absorbed by the packaging film of at least about 0.1 kGy that is delivered within a duration of at most about 30 seconds.

9. The method of claim 1 wherein the radiation energy amount comprises an absorbed dose of ionizing radiation absorbed by the packaging film of at least about 10 kGy that is delivered within a duration of at most about 5 seconds.

10. The method of claim 1 wherein:

the packaging film of the providing step comprises at least one layer comprising at least about 50% of the fullerene material by weight of the total amount of fullerene material in the packaging film; and

the radiation energy amount comprises an absorbed dose of ionizing radiation absorbed by the at least one layer of at least about 0.1 kGy that is delivered within a duration of at most about 30 seconds.

11. The method of claim 1 wherein the packaging film of the providing step has an oxygen transmission rate of at most about 100 cubic centimeters (at standard temperature and pressure) per square meter per day per 1 atmosphere of oxygen pressure differential measured at 0% relative humidity and 23°

C.

12. The method of claim 1 wherein the exposing step increases the oxygen transmission rate of the packaging film by at least about 1,000 cubic centimeters (at standard temperature and pressure) per square meter per day per 1 atmosphere of oxygen pressure differential measured at 0% relative humidity and 23°

C.

13. The method of claim 1 wherein the exposing step increases the oxygen transmission rate of the packaging film by at least about 10,000 cubic centimeters (at standard temperature and pressure) per square meter per day per 1 atmosphere of oxygen pressure differential measured at 0% relative humidity and 23°

C.

14. The method of claim 1 wherein the packaging film of the providing step comprises:

100 weight parts oxygen barrier polymer selected from one or more of ethylene/vinyl alcohol copolymer, polyvinyl alcohol, vinylidene chloride polymer, polyalkylene carbonate, polyester, polyacrylonitrile, and polyamide; and

at least about 0.001 weight parts of the fullerene material per 100 weight parts oxygen barrier polymer.

15. The method of claim 14 wherein the packaging film of the providing step comprises at least one layer comprising at least about 50% of the oxygen barrier polymer by weight of the total amount of oxygen barrier polymer in the packaging film and at least about 50% of the fullerene material by weight of the total amount of fullerene material in the packaging film.

16. The method of claim 14 wherein:

the oxygen barrier polymer comprises ethylene/vinyl alcohol copolymer; and

the packaging film of the providing step comprises at least about 0.1 weight parts of the fullerene material per 100 weight parts oxygen barrier polymer.

17. The method of claim 14 wherein:

the oxygen barrier polymer comprises vinylidene chloride polymer; and

the packaging film of the providing step comprises at least about 0.1 weight parts of the fullerene material per 100 weight parts oxygen barrier polymer.

18. The method of claim 14 wherein:

the oxygen barrier polymer comprises polyamide; and

the packaging film of the providing step comprises at least about 0.1 weight parts of the fullerene material per 100 weight parts oxygen barrier polymer.

19. The method of claim 14 wherein the packaging film of the providing step comprises:

100 weight parts oxygen barrier polymer selected from one or more of polyvinyl alcohol, polyalkylene carbonate, polyester, and polyacrylonitrile; and

at least about 0.1 weight parts of the fullerene material per 100 weight parts oxygen barrier polymer.

20. The method of claim 1 wherein the step of exposing to the effective amount of radiation energy occurs within at most about 30 seconds.

21. The method of claim 1 wherein the step of exposing to the effective amount of radiation energy occurs within at most about 1 second.

22. The method of claim 1 wherein the radiation exposure step comprises exposing to an effective amount of non-ionizing radiation comprising at least about 20% visible light energy.

23. The method of claim 1 wherein the radiation exposure step comprises exposing to an effective amount of non-ionizing radiation comprising at least about 20% infrared light energy.

24. The method of claim 1 wherein the radiation exposure step comprises exposing to an effective amount of non-ionizing radiation comprising at least about 20% ultraviolet light energy.

25. The method of claim 1 wherein the radiation exposure step comprises exposing to an effective amount of ionizing radiation comprising at least about 20% electron beam energy.

26. The method of claim 1 wherein the packaging film of the providing step comprises at least one layer comprising at least about 0.5 weight % fullerene material by weight of the layer.

27. The method of claim 1 wherein the exposing step structurally disrupts at least a portion of the fullerene material present in the packaging film of the providing step.

28. The method of claim 1 wherein the exposing step structurally disrupts at least about 50 weight % of the fullerene material present in the packaging film of the providing step.

29. The method of claim 1 wherein:

the packaging film of the providing step is unperforated; and

the exposing of the packaging film to the effective amount of radiation energy causes the packaging film to be perforated with a plurality of apertures.

30. The method of claim 1 wherein the packaging film comprises:

an outer layer of the film; and

one or more discontinuous regions supported by the outer layer of the film, wherein the one or more discontinuous regions comprise at least a portion of the fullerene material.

31. The method of claim 1 wherein the fullerene material comprises spherical fullerenes.

32. The method of claim 1 wherein the fullerene material comprises multi-walled carbon nanotubes.

33. The method of claim 1 wherein the fullerene material comprises carbon nanocones.

34. The method of claim 1 wherein the fullerene material comprises carbon nano-onions.

35. The method of claim 1 wherein the fullerene material comprises bowl-shaped fullerenes.

36. A packaging film comprising at least one layer comprising:

100 weight parts of oxygen barrier polymer selected from one or more of ethylene/vinyl alcohol copolymer, polyvinyl alcohol, vinylidene chloride polymer, polyalkylene carbonate, polyester, polyacrylonitrile, and polyamide; and

at least about 0.001 weight parts of fullerene material per 100 weight parts oxygen barrier polymer, wherein the fullerene material is selected from one or more of spherical fullerenes, bowl-shaped fullerenes, multi-walled carbon nanotubes, carbon nanocones, and carbon nano-onions.

37. The film of claim 36 wherein the at least one layer comprises at least about 60% oxygen barrier polymer and at least about 0.1% fullerene material based on the weight of the at least one layer.

38. The film of claim 36 wherein the fullerene material comprises spherical fullerenes.

39. The film of claim 36 wherein the fullerene material comprises multi-walled carbon nanotubes.

40. The film of claim 36 wherein the fullerene material comprises carbon nanocones.

41. The film of claim 36 wherein the fullerene material comprises carbon nano-onions.

42. The film of claim 36 wherein the fullerene material comprises bowl-shaped fullerenes.

43. The film of claim 36 wherein the oxygen barrier polymer comprises ethylene/vinyl alcohol copolymer.

44. The film of claim 36 wherein the oxygen barrier polymer comprises vinylidene chloride polymer.

45. The film of claim 36 wherein the oxygen barrier polymer is selected from one or more of polyvinyl alcohol, polyalkylene carbonate, polyester, polyacrylonitrile, and polyamide.

46. The film of claim 36 wherein the packaging film of the providing step has an average transparency of at least about 85%.

47. A packaged food product comprising:

a package comprising the packaging film of claim 36 and defining an interior space;

a food product enclosed in the interior space of the package; and

a modified atmosphere enclosed in the interior space of the package.

48. A method of supplying a packaged food product comprising the following steps:

providing the packaged food product of claim 47;

and

exposing the packaging film of the packaged food product to an amount of radiation energy effective to increase the oxygen transmission rate of the packaging film by at least about 100 cubic centimeters (at standard temperature and pressure) per square meter per day per 1 atmosphere of oxygen pressure differential measured at 0% relative humidity and 23°

C.

49. A packaging film comprising:

at least one layer; and

one or more discontinuous regions supported by the at least one layer, wherein the one or more discontinuous regions comprise at least about 0.001 weight % of fullerene material based on the weight of the film.

50. The film of claim 49 wherein the at least one layer is an outer layer of the film.

51. The film of claim 49 wherein the at least one layer is an internal layer of the film, whereby the one or more discontinuous regions are between at least two layers of the film.