Compostable packaging for containment of liquids

• US 5,736,204 A
• Filed: 06/07/1994
• Issued: 04/07/1998
• Est. Priority Date: 10/16/1992
• Status: Expired due to Fees

• Current Assignee: Estate of Leonard Pearlstein
• Original Assignee: Estate of Leonard Pearlstein
• Inventors: Suskind, Stuart P.
• Primary Examiner(s): Seidleck, James J.
• Assistant Examiner(s): Williamson, Michael A.
• Application Number:
  US08/255,807
• Time in Patent Office: 1,400 Days
• Field of Search: 428/34.2, 428/34.3, 264/173, 264/512, 264/524, 206/233, 206/494, 206/812, 206/209, 206/524.2
• US Class Current: 428/34.2
• CPC Class Codes: B32B 2307/31 Heat sealable
• CPC Class Codes: B32B 2307/554 Wear resistance
• CPC Class Codes: B32B 2439/70 Food packaging
• CPC Class Codes: B32B 27/10 of paper or cardboard
• 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 27/36 comprising polyesters
• CPC Class Codes: B32B 29/00 Layered products comprising a layer of paper or cardboard
• CPC Class Codes: B65D 65/466 Bio- or photodegradable packaging materials
• CPC Class Codes: D21H 19/22 Polyalkenes, e.g. polystyrene
• CPC Class Codes: D21H 19/28 Polyesters
• CPC Class Codes: D21H 23/30 Pretreatment of the paper D21H23/70, D21H23/76 take precedence
• CPC Class Codes: D21H 27/10 Packing paper packaging materials of special type or form B65D65/38
• CPC Class Codes: D21H 27/36 Films made from synthetic macromolecular compounds
• 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 428/1307 Bag or tubular film [e.g., pouch, flexible food casing, envelope, 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 which is coated with a material capable of degrading to carbon dioxide, water and biomass under composting conditions.

Claims

1. A method of making a compostable package for containing material comprising:

providing a base of paperboard having an external surface and an internal surface;

treating at least said internal surface with corona discharge or a flame;

coating at least the internal surface of said paperboard to a thickness of from about 0.5 mil to about 2.0 mils with an aliphatic polyester capable of preventing leaks,

wherein at least said treated internal surface and said coating define a water insensitive inter-facial bond free of adhesive,

wherein said base and said aliphatic polyester are compostable at substantially the same rate to carbon dioxide, water and biomass, and

wherein said base has a cross-directional Taber stiffness of 50 to 150, a thickness of from about 4 to 25 mils, and a basis weight of from about 35 to about 220 lbs/ream;

forming said paperboard into a container wherein said internal surface having said aliphatic polyester thereon forms the interior of the container and said external surface forms the exterior of the container; and

filling the container with a liquid or liquid containing material therein and sealing said container.

2. The method according to claim 1, wherein said aliphatic polyester is heat sealable, flexible, adhesive, resistant to stress cracks and abrasion resistant.

3. The method according to claim 1, wherein said aliphatic polyester is selected from the group consisting of polycaprolactone, a polyester of 3-hydroxybutyric acid, a polyester of 3-hydroxyvaleric acid, polyglycolic acid and polyactide acid, and copolymers and mixtures thereof.

4. The method according to claim 3, wherein said aliphatic polyester is polycaprolactone.

5. The method according to claim 1, wherein said aliphatic polyester further comprises a blend of a second polymer selected from the group consisting of PVC, SAN, ABS phenoxy, polycarbonate, nitrocellulose, poly vinylidene chloride, styrene/allyl alcohol copolymers, polyethylene, polypropylene, natural rubber, styrene/butadiene, elastomer and block copolymers, polyvinylacetate, polybutadiene, ethylene/propylene rubber and starch.

6. The method according to claim 5, wherein the second polymer is polyethylene.

7. The method according to claim 1, wherein the liquid or liquid containing material is selected from the group consisting of milk, juice, fruit punch, soda, frozen juice, iced tea, fabric softener, butter, margarine, cosmetics, shampoo, conditioner, suntan lotion, body lotion, pancake syrup, cooking oil, processed grains, fruits, vegetables, applesauce pasta sauces, frozen vegetables, frozen fruits, breads, bread products and single-use wet wipes.

8. The method according to claim 7, wherein the liquid or liquid containing material is single-use wet wipes.

15. The method according to claim 7, wherein the liquid or liquid containing material is selected from the group consisting of milk, juice, fruit punch, soda, frozen juice, iced tea, fabric softener, butter, margarine, cosmetics, shampoo, conditioner, suntan lotion, body lotion, pancake syrup, cooking oil, processed grains, fruits, vegetables, applesauce pasta sauces, frozen vegetables, frozen fruits, breads, bread products and single-use wet wipes.

16. The method according to claim 15, wherein the liquid or liquid containing material is single-use wet wipes.

9. A method of using a compostable package for containing a liquid or liquid containing material comprising;

providing a crush resistant base of paperboard having an internal and external surface;

treating at least said internal surface with corona discharge or a flame;

coating at least the internal surface of said paperboard to a thickness of from about 0.5 mil to about 2.0 mils with an aliphatic polyester capable of preventing leaks,

wherein at least said treated internal surface and said coating define a water insensitive inter-facial bond free of adhesive,

wherein said base and said aliphatic polyester are compostable at substantially the same rate to carbon dioxide, water and biomass, and

wherein said base had a cross-directional Taber stiffness of 50 to 150, a thickness of from about 4 to 25 mils, and a basis weight of from bout 35 to about 220 lbs/ream;

forming said paperboard into a container wherein said internal surface having said aliphatic polyester thereon forms the interior of the container and said external surface forms the exterior of the container;

sealing the edges and bottom of said container; and

placing into said container a liquid or a material containing a liquid.

10. The method according to claim 9, wherein the aliphatic polyester is sealable, flexible, adhesive, resistant to stress cracks and abrasion resistant.

11. The method according to claim 9, wherein the aliphatic polyester is a linear thermoplastic aliphatic polyester selected from the group consisting of polycaprolactone, a polyester of 3-hydroxybutyric acid, a polyester of 3-hydroxyvaleric acid, polyglycolic acid and polyactide acid, and copolymers and mixtures thereof.

12. The method according to claim 11, wherein the aliphatic polyester is polycaprolactone.

13. The method according to claim 9, wherein said aliphatic polyester further comprises a second polymer selected from the group consisting of PVC, SAN, ABS, phenoxy, polycarbonate, nitrocellulose, polyvinylidene chloride, styrene/allyl alcohol copolymers, polyethylene, polypropylene, natural rubber, styrene/butadiene, elastomer and block copolymers, polyvinylacetate, polybutadiene, ethylene/propylene rubber and starch.

14. The method according to claim 13, wherein the second polymer is polyethylene.

17. A method of making a compostable package for containing a liquid or a liquid containing material comprising;

providing a base of paperboard having an internal and external surface;

treating said internal and external surface with corona discharge or a flame;

coating both the internal and external surfaces of said paperboard by extrusion lamination to a thickness of from about 0.5 mil to about 2.0 mils with a linear thermoplatic aliphatic polyester capable of preventing leaks,

wherein said internal and external surface and said coating define a water insensitive inter-facial bond free of adhesive,

wherein said base and said aliphatic polyester are compostable at substantially the same rate to carbon dioxide, water and biomass, and

wherein said base has a cross-directional Taber stiffness of 50 to 150, a thickness of from 4 to 25 mils, and a basis weight of from about 35 to about 220 lbs/ream;

forming said paperboard into a container wherein said internal surface having said aliphatic polyester thereon forms the interior of the container and said external surface forms the exterior of the container; and

filling the container with a liquid or liquid containing material and sealing said container.