Oxygen impermeable leak free container

• US 4,859,513 A
• Filed: 05/09/1988
• Issued: 08/22/1989
• Est. Priority Date: 05/09/1988
• Status: Expired due to Fees

• Current Assignee: International Paper Company
• Original Assignee: International Paper Company
• Inventors: Evans, Donald, Gibbons, Charles E., Whillock, Allan A., Marano, Gerald A., Lanham, Robert L., Kittrell, James M.
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Harbin, Alisa
• Application Number:
  US07/191,337
• Time in Patent Office: 470 Days
• Field of Search: 428/349, 428/354, 428/35
• US Class Current: 428/34.2
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: Y10T 428/1303 Paper containing [e.g., paperboard, cardboard, fiberboard, etc.]
• 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 428/31692 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31746 Polymer of monoethylenically unsaturated hydrocarbon
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31906 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31913 Monoolefin polymer

Abstract

The present invention relates to an improved container for food and non-food products. The container utilizes a novel paperboard barrier laminate structure which maintains an isolated gas environment in the container. The laminate makes use of high strength, heat-resistant and caulking polymer layers which prevent pinholes, cuts, or cracking of the barrier layers during blank conversion, package formation, and package distrubution. In addition, the novel polymer resin layers act to caulk the seams and channels present in the carton providing a sealed leak free container.

Claims

1. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container comprising:

(a) a mechanically stable structural substrate;

(b) an outer layer of a heat-sealable low density polyethylene polymer coated on said outer surface of said mechanically stable structural substrate;

(c) an inner coextruded layer of;

a first low density polyethylene polymer, an abuse resistant polymer resin, a first adhesive tie layer, an oxygen barrier material layer, a second adhesive tie layer and a caulking polymer resin selected from the group consisting of zinc salts of ethylene/methacrylic acid copolymers, sodium salts of ethylene/methacrylic acid copolymers, ethylene/acrylic acid copolymers, ethylene/methacrylic acid copolymers, ethylene/vinyl acetate copolymers, and ethylene/methacrylate copolymers, all coextruded on said inner surface of said mechanically stable structural substrate; and

(d) a heat-sealable product contact layer of a low density polyethylene polymer extrusion coated on said outer surface of said coextruded layer, which is heat-sealable with the outer layer of low density polyethylene polymer on conventional equipment at temperatures ranging from 250°

F. to 500°

F.

2. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 1, wherein said mechanically stable structural substrate is selected from the group consisting of bleached paperboard, unbleached paperboard, corrugated board, high density polyethylene, and polypropylene.

3. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 1, wherein said oxygen barrier material layer is selected from the group consisting of aluminum foil, polyvinyl alcohol, polyethylene terephthalate ethylene vinyl alcohol copolymer, glycol-modified polyethylene terephthalate, acid-modified polyethylene terephthalate, polybutylene terephthalate, vinylidene chloride copolymer, polyvinyl chloride polymer, vinyl chloride copolymer, polyamide polymer and polyamide copolymer.

4. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 1, wherein said abuse resistant polymer resin exhibits a tensile strength of 10,000 psi or greater.

5. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 4, wherein said abuse resistant polymer is selected from the group consisting of polyamide polymers, polyethylene terephthalate, polybutylene terephthalate, and ethylene vinyl alcohol copolymer.

6. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 1, wherein said caulking polymer resin exhibits a melt flow index ranging from 4.5-14.0.

7. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 6, wherein said caulking polymer resin is selected form zinc salts of ethylene methacrylic acid copolymers or sodium slats of ethylene methacrylic acid copolymers.

8. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 1, wherein said adhesive tie layer is selected from the group consisting of:

ethylene based copolymers with grafted functional groups, modified polyethylene resin containing vinyl acetate acrylate; and

methacrylate type comonomers, and polyethylene copolymer based material with grafted functional groups.

9. An oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 1, wherein said mechanically stable structural substrate is paperboard, said oxygen barrier material layer is aluminum foil, said abuse resistant polymer resin is a polyamide polymer having a tensile strength greater than 10,000 psi, and wherein said caulking polymer resin is a zinc salt of ethylene methacrylic acid copolymer having a melt flow index ranging from 4.5-14.0.

26. An oxygen impermeable leak free container, said container constructed from a laminate as claimed in claim 19, wherein said adhesive tie layer is selected from the group consisting of an oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim 1, wherein said adhesive tie layer is selected from the group consisting of:

ethylene based copolymers with grafted functional groups, modified polyethylene resin containing vinyl acetate acrylate; and

methacrylate type comonomers, and polyethylene copolymer based materials with grafted functional groups.

10. An oxygen impermeable side-seamed blank, said blank constructed from a laminate comprising:

(a) a mechanically stable structural substrate;

(b) an outer layer of a heat-sealable low density polyethylene polymer coated on said outer surface of said mechanically stable structural substrate;

(c) an inner coextruded layer of;

a first low density polyethylene polymer, an abuse resistant polymer resin, a first adhesive tie layer, an oxygen barrier material layer, a second adhesive tie layer and a caulking polymer resin selected from the group consisting of zinc salts of ethylene/methacrylic acid copolymers, sodium salts of ethylene/methacrylic acid copolymers, ethylene/acrylic acid copolymers, ethylene/methacrylic acid copolymers, ethylene/vinyl acetate copolymers, and ethylene/methacrylate copolymers, all coextruded on said inner surface of said mechanically stable structural substrate; and

(d) a heat-sealable product contact layer of a low density polyethylene polymer extrusion coated on said outer surface of said coextruded layer, which is heat-sealable with the outer layer of low density polyethylene polymer on conventional equipment at temperatures ranging from 250°

F. to 500°

F.

11. An oxygen impermeable side-seamed blank, said blank constructed from a laminate as claimed in claim 10, wherein said mechanically stable structural substrate is selected from the group consisting of bleached paperboard, unbleached paperboard, corrugated board, high density polyethylene, and polypropylene.

12. An oxygen impermeable side-seamed blank, said blank constructed from a laminate as claimed in claim 10, wherein said oxygen barrier material layer is selected from the group consisting of aluminum foil, polyvinyl alcohol, polyethylene terephthalate ethylene vinyl alcohol copolymer, glycol-modified polyethylene terephthalate, acid-modified polyethylene terephthalate, polybutylene terephthalate, vinylidene chloride copolymer, polyvinyl chloride polymer, vinyl chloride copolymer, polyamide polymer and polyamide copolymer.

13. An oxygen impermeable side-seamed blank, said blank constructed from a laminate as claimed in claim 10, wherein said abuse resistant polymer resin exhibits a tensile strength of 10,000 psi or greater.

14. An oxygen impermeable side-seamed blank, said blank constructed from a laminate as claimed in claim 13, wherein said abuse resistant polymer is selected from the group consisting of polyamide polymers, polyethylene terephthalate, polybutylene terephthalate, and ethylene vinyl alcohol copolymer.

15. An oxygen impermeable side-seamed blank, said blank constructed from a laminate as claimed in claim 10, wherein said caulking polymer resin exhibits a melt flow index ranging from 4.5-14.0.

16. An oxygen impermeable side-seamed blank, said blank constructed from a laminate as claimed in claim 15, wherein said caulking polymer resin is selected from zinc salts of ethylene methacrylic acid copolymers or sodium salts of ethylene methacrylic acid copolymers.

17. An oxygen impermeable side-seamed blank, said blank constructed from a laminate as claimed in claim 10, wherein said adhesive tie layer is selected from the group consisting of an oxygen barrier laminate structure for producing an oxygen impermeable leak free container, said laminate as claimed in claim I, wherein said adhesive tie layer is selected from the group consisting of:

ethylene based copolymers with grafted functional groups, modified polyethylene resin containing vinyl acetate acrylate; and

methacrylate type comonomers, and polyethylene copolymer based materials with grafted functional groups.

18. An oxygen impermeable side-seamed blank, said blank constructed from a laminate as claimed in claim 10, wherein said mechanically stable structural substrate is paperboard, said oxygen barrier material layer is aluminum foil, said abuse resistant polymer resin is a polyamide polymer having a tensile strength greater than 10,000 psi, and wherein said caulking polymer resin is a zinc salt of ethylene methacrylic acid copolymer having a melt flow index ranging from 4.5-14.0.

19. An oxygen impermeable leak free container, said container constructed from a laminate comprising:

(a) a mechanically stable structural substrate;

(b) an outer layer of a heat-sealable low density polyethylene polymer coated on said outer surface of said mechanically stable structural substrate;

(c) an inner coextruded layer of;

a first low density polyethylene polymer, an abuse resistant polymer resin, a first adhesive tie layer, an oxygen barrier material layer, a second adhesive tie layer and a caulking polymer resin selected from the group consisting of zinc salts of ethylene/methacrylic acid copolymers, sodium salts of ethylene/methacrylic acid copolymers, ethylene/acrylic acid copolymers, ethylene/methacrylic acid copolymers, ethylene/vinyl acetate copolymers, and ethylene/methacrylate copolymers, all coextruded on said inner surface of said mechanically stable structural substrate; and

(d) a heat-sealable product contact layer of a low density polyethylene polymer extrusion coated on said outer surface of said coextruded layer, which is heat-sealable with the outer layer of low density polyethylene polymer on conventional equipment at temperatures ranging from 250°

F. to 500°

F.

20. An oxygen impermeable leak free container, said container constructed from a laminate as claimed in claim 19, wherein said mechanically stable structural substrate is selected from the group consisting of bleached paperboard, unbleached paperboard, corrugated board, high density polyethylene, and polypropylene.

21. An oxygen impermeable leak free container, said container constructed from a laminate as claimed in claim 19, wherein said oxygen barrier material layer is selected from the group consisting of aluminum foil, polyvinyl alcohol, polyethylene terephthalate ethylene vinyl alcohol copolymer, glycol-modified polyethylene terephthalate, acid-modified polyethylene terephthalate, polybutylene terephthalate, vinylidene chloride copolymer, polyvinyl chloride polymer, vinyl chloride copolymer, polyamide polymer and polyamide copolymer.

22. An oxygen impermeable leak free container, said container constructed from a laminate as claimed in claim 19, wherein said abuse resistant polymer resin exhibits a tensile strength of 10,000 psi or greater.

23. An oxygen impermeable leak free container, said container constructed from a laminate as claimed in claim 22, wherein said abuse resistant polymer is selected from the group consisting of polyamide polymers, polyethylene terephthalate, polybutylene terephthalate, and ethylene vinyl alcohol copolymer.

24. An oxygen impermeable leak free container, said container constructed from a laminate as claimed in claim 19, wherein said caulking polymer resin exhibits a melt flow index ranging from 4.5-14.0.

25. An oxygen impermeable leak free container, said container constructed from a laminate as claimed in claim 24, wherein said caulking polymer resin is selected from zinc salts of ethylene methacrylic acid copolymers or sodium salts of ethylene methacrylic acid copolymers.

27. An oxygen impermeable leak free container, said container constructed from a laminate as claimed in claim 19, wherein said mechanically stable structural substrate is paperboard, said oxygen barrier material layer is aluminum foil, said abuse resistant polymer resin is a polyamide polymer having a tensile strength greater than 10,000 psi, and wherein said caulking polymer resin is a zinc salt of ethylene methacrylic acid copolymer having a melt flow index ranging from 4.5-14.0.