Degradable package for containment of liquids

• US 5,540,962 A
• Filed: 04/06/1994
• Issued: 07/30/1996
• Est. Priority Date: 10/16/1992
• Status: Expired due to Fees

• Current Assignee: Leonard Pearlstein
• Original Assignee: Leonard Pearlstein
• Inventors: Suskind, Stuart P.
• Primary Examiner(s): Seidleck, James J.
• Assistant Examiner(s): Williamson, Michael A.
• Application Number:
  US08/223,707
• Time in Patent Office: 846 Days
• Field of Search: 428/34.2, 428/34.3, 428/481, 428/34.6, 428/35.7, 428/513, 428/514, 206/233, 206/494, 206/812, 206/209, 206/524.2
• US Class Current: 428/34.2
• CPC Class Codes: B05D 3/00 Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials successively applying liquids or other fluent materials B05D1/36; drying ovens F26B
• CPC Class Codes: B32B 2307/7163 Biodegradable
• CPC Class Codes: B32B 27/10 of paper or cardboard
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B65D 5/563 Laminated linings; Coatings
• CPC Class Codes: B65D 65/42 Applications of coated or impregnated materials
• CPC Class Codes: B65D 65/466 Bio- or photodegradable packaging materials
• CPC Class Codes: B65D 71/00 Bundles of articles held together by packaging elements for convenience of storage or transport, e.g. portable segregating carrier for plural receptacles such as beer cans or pop bottles; Bales of material
• CPC Class Codes: D21H 19/28 Polyesters
• CPC Class Codes: D21H 19/82 superposed D21H19/84 takes precedence
• CPC Class Codes: D21H 19/84 on both sides of the substrate
• CPC Class Codes: D21H 27/10 Packing paper packaging materials of special type or form B65D65/38
• CPC Class Codes: Y02W 90/10 Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics
• CPC Class Codes: Y10S 206/812 Packaged towel
• CPC Class Codes: Y10T 428/1303 Paper containing [e.g., paperboard, cardboard, fiberboard, etc.]
• CPC Class Codes: Y10T 428/1317 Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/3179 Next to cellulosic
• CPC Class Codes: Y10T 428/31902 Monoethylenically unsaturated
• CPC Class Codes: Y10T 428/31906 Ester, halide or nitrile of addition polymer

Abstract

A compostable paperboard container and package for liquids is coated with a polymeric material capable of degrading under composting conditions and subsequently in the presence of light to form carbon dioxide, water, and biomass.

Claims

1. A compostable container for packaging a liquid or liquid containing material comprising:

a base of paperboard having two sides;

a coating of a biodegradable linear aliphatic polyester or paraffin wax on the side of the base which constitutes the outer surface of the container;

a coating of a photodegradable polyolefin on the side of the base which constitutes the inner surface of the container;

said container being degradable to form carbon dioxide, water and biomass; and

said base with said biodegradable coating and said photodegradable coating having a moisture vapor transmission rate of less than about 0.87 grams per 100 square inches per day.

2. The container according to claim 1, wherein each coating is from about 0.5 to about 3.0 mils. thick.

3. The container according to claim 1, wherein the biodegradable coating is heat sealable, flexible, adhesive, resistant to stress cracks, and abrasion resistant.

4. The container according to claim 1, wherein the biodegradable aliphatic polyester is selected from the group consisting of polycaprolactone, poly-3-hydroxybutyric acid, poly-3-hydroxyvaleric acid, polyglycolic acid, copolymers of glycolic acid and lactic acid and polylactide.

5. The container according to claim 4, wherein the biodegradable aliphatic polyester is polycaprolactone.

6. The container according to claim 2, wherein said biodegradable aliphatic polyester and/or said polyolefin further contain a resin selected from the group consisting of PVC, SAN, ABS, phenoxy, polycarbonate, nitrocellulose, polyvinylidene chloride, a styrene/allyl alcohol copolymer, polyethylene, polypropylene, natural rubber, a styrene/butadiene elastomer and block copolymer, polyvinylacetate, polybutadiene, ethylene/propylene rubber, starch, and thermoplastic segmented polyurethane.

7. The container according to claim 6, wherein the resin is polyethylene.

8. The container according to claim 1, wherein the photodegradable layer is modified polyethylene.

9. The container according to claim 1, wherein the photodegradable layer is rendered photodegradable by the incorporation of a carbonyl group into the polyolefin.

10. The container according to claim 1, wherein the photodegradable layer is rendered photodegradable by incorporation of a ketone group into the polyolefin.

11. The container according to claim 1, wherein the photodegradable layer is rendered photodegradable by the incorporation of a salt of a polyvalent transition metal into the polyolefin.

12. The container according to claim 1, wherein the photodegradable layer is rendered photodegradable by the incorporation of an alkoxylated ethylenically unsaturated compound into the polyolefin.

13. The container according to claim 1, in which degradation of the paperboard and biodegradable aliphatic polyester occur by biodegradation and degradation of the polyolefin coating occurs by photodegradation.

14. The container according to claim 1, further comprising paraffin wax as a layer under or over one or both of the coatings or paraffin wax is mixed with one or both of the coatings.

15. A compostable container for packaging a liquid or liquid containing material comprising:

a base having two sides and comprising a photodegradable polyolefin positioned between two paperboard substrates;

a coating of a biodegradable linear aliphatic polyester or paraffin wax on both sides of said base;

said container being degradable to form carbon dioxide, water and biomass; and

said base with said biodegradable coating and said photodegradable coating having a moisture vapor transmission rate of less than about 0.87 grams per 100 square inches per day.

16. The container according to claim 15, wherein each coating and said polyolefin is from about 0.5 to about 3.0 mils. thick.

17. The container according to claim 15, wherein the biodegradable coating is heat sealable, flexible, adhesive, resistant to stress cracks, and abrasion resistant.

18. The container according to claim 15, wherein the biodegradable aliphatic polyester is selected from the group consisting of polycaprolactone, poly-3-hydroxybutyric acid, poly-3-hydroxyvaleric acid, polyglycolic acid, copolymers of glycolic acid and lactic acid and polylactide.

19. The container according to claim 18, wherein the biodegradable aliphatic polyester is polycaprolactone.

20. The container according to claim 16, wherein said biodegradable aliphatic polyester and/or said polyolefin further contain a resin selected from the group consisting of PVC, SAN, ABS, phenoxy, polycarbonate, nitrocellulose, polyvinylidene chloride, a styrene/allyl alcohol copolymer, polyethylene, polypropylene, natural rubber, a styrene/butadiene elastomer and block copolymer, polyvinylacetate, polybutadiene, ethylene/propylene rubber, starch, and thermoplastic segmented polyurethane.

21. The container according to claim 20, wherein the resin is polyethylene.

22. The container according to claim 15, wherein the photodegradable polyolefin is modified polyethylene.

23. The container according to claim 15, wherein the photodegradable layer is rendered photodegradable by the incorporation of a carbonyl group into the polyolefin.

24. The container according to claim 15, wherein the photodegradable layer is rendered photodegradable by incorporation of a ketone group into the polyolefin.

25. The container according to claim 15, wherein the photodegradable layer is rendered photodegradable by the incorporation of a salt of a polyvalent transition metal into the polyolefin.

26. The container according to claim 15, wherein the photodegradable layer is rendered photodegradable by the incorporation of an alkoxylated ethylenically unsaturated compound into the polyolefin.

27. The container according to claim 15, in which degradation of the paperboard and biodegradable aliphatic polyester occur by biodegradation and degradation of the polyolefin coating occurs by photodegradation.

28. The container according to claim 15, wherein the coating is a biodegradable linear aliphatic polyester and further comprising paraffin wax as a layer under or over one or both of the coatings or paraffin wax mixed with one or both of the coatings.