Drying agent in multi-layer polymeric structure

• US 4,425,410 A
• Filed: 09/15/1982
• Issued: 01/10/1984
• Est. Priority Date: 12/10/1979
• Status: Expired due to Term

• Current Assignee: Pechiney Plastic Packaging Incorporated (Rio Tinto Limited)
• Original Assignee: United States Gypsum Company (GEBR Knauf Verwaltungsgesellschaft KG)
• Inventors: Tsai, Boh C., Farrell, Christopher J., Wachtel, James A.
• Primary Examiner(s): McCamish, Marion
• Assistant Examiner(s): BUFFALOW, EDITH
• Application Number:
  US06/418,199
• Time in Patent Office: 482 Days
• Field of Search: 428/516, 428/520, 428/35, 428/701, 428/689, 428/688, 428/500, 426/127, 426/124, 426/415, 252/194, 206/204, 206/524.5
• US Class Current: 428/516
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 428/1341 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/1383 Vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit is sandwiched between layers [continuous layer]
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31913 Monoolefin polymer
• CPC Class Codes: Y10T 428/3192 Next to vinyl or vinylidene chloride polymer

Abstract

In a multi-layer polymeric structure having an interior oxygen barrier layer of a moisture sensitive polymeric material such as ethylene-vinyl alcohol, drying agents are incorporated in the structure, particularly in a layer or layers proximate to the barrier layer, to limit the moisture content of the barrier layer to maintain barrier properties.

Claims

1. In a multi-layer polymeric structure having an interior layer of a moisture sensitive oxygen barrier polymer, the improvement which comprises the incorporation of a drying agent entrapped in the moisture sensitive oxygen barrier layer.

2. The multi-layer structure of claim 1 wherein the drying agent is calcium chloride.

3. The multi-layer structure of claim 1 wherein the drying agent is sodium chloride.

4. The multi-layer structure of claim 1 wherein the drying agent is sodium phosphate-di-basic.

5. The multi-layer structure of claim 1 wherein the drying agent is sucrose.

6. The multi-layer structure of claim 1 wherein the drying agent is potassium carbonate.

7. The multi-layer structure of claim 1 wherein the drying agent is aluminum sulphate.

8. The multi-layer structure of claim 1 wherein the drying agent is magnesium sulphate.

9. The multi-layer structure of claim 1 wherein the drying agent is magnesium chloride.

10. The multi-layer structure of claim 1 wherein the drying agent is sodium nitrate.

11. The multi-layer structure of claim 1 wherein the drying agent is ammonium sulphate.

12. The multi-layer structure of claim 1 wherein the drying agent is ammonium phosphate-monobasic.

13. The multi-layer structure of claim 1 wherein the drying agent is potassium bromide.

14. The multi-layer structure of claim 1 wherein the drying agent has a high drying capacity at a water activity below about 0.85 and wherein the drying capacity at about 0.85 water activity is greater than the drying capacity at about 0.1 water activity.

15. In a multi-layer polymeric structure having a layer of a moisture sensitive oxygen barrier polymer, and exterior layers of structural polymer, the improvment which comprises the incorporation of a drying agent entrapped in one of the exterior layers.

16. The multi-layer structure of claim 15 wherein the drying agent is calcium chloride.

17. The multi-layer structure of claim 15 wherein the drying agent is sodium chloride.

18. The multi-layer structure of claim 15 wherein the drying agent is sodium phosphate-di-basic.

19. The multi-layer structure of claim 15 wherein the drying agent is ammonium chloride.

20. The multi-layer structure of claim 15 wherein the drying agent is sucrose.

21. The multi-lyaer structure of claim 15 wherein the drying agent is potassium carbonate.

22. The multi-layer structure of claim 15 wherein the drying agent is potassium aluminum sulphate.

23. The multi-layer structure of claim 15 wherein the drying agent is magnesium sulphate.

24. The multi-layer structure of claim 15 wherein the drying agent is magnesium chloride.

25. The multi-layer structure of claim 15 wherein the drying agent is sodium nitrate.

26. The multi-layer structure of claim 15 wherein the drying agent is ammonium sulphate.

27. The multi-layer structure of claim 15 wherein the drying agent is ammonium phosphate-monobasic.

28. The multi-layer structure of claim 15 wherein the drying agent is potassium bromide.

29. In a multi-layer polymeric structure having a layer of a moisture sensitive oxygen barrier polymer, and exterior layers of structural polymer, the improvement which comprises the incorporation of a drying agent entrapped in each of the exterior layers.