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US-12618198-B2 - Barrier recycled paperboard and method for manufacturing thereof

US12618198B2US 12618198 B2US12618198 B2US 12618198B2US-12618198-B2

Abstract

A coated paperboard includes a recycled paperboard substrate having a first side and a second side, a first aqueous barrier coating applied over the first side, and a second aqueous barrier coating applied over the first aqueous barrier coating. The first aqueous barrier coating is formed from a mixture of binder and pigment. The second aqueous barrier coating is formed from a mixture of binder and pigment.

Inventors

  • Terry L. Clark
  • Scott J. REIGLE
  • Jiebin Pang
  • William G. DEATS

Assignees

  • WESTROCK MWV, LLC

Dates

Publication Date
20260505
Application Date
20210308

Claims (20)

  1. 1 . A coated paperboard comprising: a recycled paperboard substrate having a first side and a second side, wherein the recycled paperboard substrate is produced from at least 50%, by weight, recovered fibers; a first layer of aqueous barrier coating applied over the first side, wherein the first layer of aqueous barrier coating comprises a first mixture of binder and pigment, wherein the binder of the first layer of aqueous barrier coating is present in the first mixture in an amount of 30 to 50 parts per 100 parts of pigment by weight; and a second layer of aqueous barrier coating applied over the first layer of aqueous barrier coating, wherein the second layer of aqueous barrier coating comprises a second mixture of binder and pigment, wherein the binder of the second layer of aqueous barrier coating is present in the second mixture in an amount of 30 to 50 parts per 100 parts of pigment by weight, wherein the coated paperboard has a 3M kit test value of at least 5, a 30-minute oil Cobb test of at most 5 grams per square meter, a 2-minute water Cobb of less than 60 grams per square meter, a water vapor transmission rate of less than 800 grams per square meter per day, and is repulpable to the extent that after repulping the percentage accepts is at least 85%.
  2. 2 . The coated paperboard of claim 1 , wherein the recycled paperboard substrate is produced from at least 90%, by weight, recovered fibers.
  3. 3 . The coated paperboard of claim 1 , wherein the recycled paperboard substrate has a caliper thickness of at least 4 points (0.004 inch).
  4. 4 . The coated paperboard of claim 1 , wherein the recycled paperboard substrate has a caliper thickness of ranging from 4 points to 36 points (0.004 inch to 0.036 inch).
  5. 5 . The coated paperboard of claim 1 , further comprising a basecoat layer between the first side of the recycled paperboard substrate and the first layer of aqueous barrier coating.
  6. 6 . The coated paperboard of claim 5 , wherein the basecoat layer comprises a third mixture of binder and pigment.
  7. 7 . The coated paperboard of claim 5 , wherein the basecoat layer comprises a third mixture of binder and pigment, wherein the binder of the basecoat layer is present in the mixture in an amount of 5-35 parts per 100 parts of pigment by weight.
  8. 8 . The coated paperboard of claim 5 , wherein the basecoat layer comprises a third mixture of binder and pigment, wherein the binder of the basecoat layer comprises at least one of latex binder and natural binder.
  9. 9 . The coated paperboard of claim 5 , wherein the basecoat layer comprises a third mixture of binder and pigment, wherein the pigment of the basecoat layer comprises one or more of clay, calcium carbonate, and titanium oxide.
  10. 10 . The coated paperboard of claim 5 , wherein the basecoat layer has a coat weight from 2 to 14 pounds per 3000 ft 2 .
  11. 11 . The coated paperboard of claim 1 , wherein the binder of the first layer of aqueous barrier coating comprises latex.
  12. 12 . The coated paperboard of claim 1 , wherein the first layer of aqueous barrier coating further comprises a natural co-binder.
  13. 13 . The coated paperboard of claim 1 , wherein the first layer of aqueous barrier coating comprises an additive, wherein the additive is present in the first mixture in an amount of up to 4 parts per 100 parts of pigment by weight.
  14. 14 . The coated paperboard of claim 1 , wherein the binder of the second layer of aqueous barrier coating comprises latex.
  15. 15 . The coated paperboard of claim 1 , wherein the second layer of aqueous barrier coating further comprises a natural co-binder.
  16. 16 . The coated paperboard of claim 1 , wherein the second layer of aqueous barrier coating comprises an additive, wherein the additive is present in the second mixture in an amount of up to 4 parts per 100 parts of pigment by weight.
  17. 17 . The coated paperboard of claim 1 , wherein a 3M kit test value is at least 6.
  18. 18 . The coated paperboard of claim 1 , wherein the coated paperboard has a 30-minute oil Cobb test of at most 3 grams per square meter.
  19. 19 . The coated paperboard of claim 1 , wherein the coated paperboard has a water vapor transmission rate of less than 700 grams per square meter per day.
  20. 20 . The coated paperboard of claim 1 , wherein the coated paperboard is repulpable to the extent that after repulping the percentage accepts is at least 90%.

Description

PRIORITY This application claims priority from U.S. Ser. No. 62/992,305 filed on Mar. 20, 2020. FIELD The present application relates to the field of recycled paperboard substrates having enhanced barrier properties. BACKGROUND Food or food service containers using paperboard often require enhanced barrier properties of the paperboard, including oil, grease, moisture, vapor, and/or oxygen barrier. Polyethylene extrusion coating and specialty chemical (wax, fluorochemicals, etc.) treatment have been employed to provide oil and grease resistance to paperboard containers. However, paperboard treated with wax or coated with polyethylene, which is often used in oil and grease resistant packaging, has difficulties in repulping and is not as easily recyclable as conventional paperboard. Paperboard treated with specialty chemicals such as fluorochemicals have potential health, safety, and environment concerns. Sustainable and environmentally friendly packaging is increasingly demanded for containers for food or food service packaging. Accordingly, those skilled in the art continue with research and development in the field of paperboard substrates having enhanced barrier properties and sustainability. SUMMARY In one embodiment, a coated paperboard includes a recycled paperboard substrate having a first side and a second side, a first aqueous barrier coating applied over the first side, and a second aqueous barrier coating applied over the first aqueous barrier coating. The first aqueous barrier coating is formed from a mixture of binder and pigment. The second aqueous barrier coating is formed from a mixture of binder and pigment. In another embodiment, there is a method for manufacturing coated paperboard. The method includes applying a first aqueous barrier coating over a first side of a recycled paperboard substrate and applying a second aqueous barrier coating over the first aqueous barrier coating. The first aqueous barrier coating is formed from a mixture of binder and pigment. The second aqueous barrier coating is formed from a mixture of binder and pigment. In yet another embodiment, a coated paperboard includes a recycled paperboard substrate having a first side and a second side and a first aqueous barrier coating applied over the first side. The first aqueous barrier coating is formed from a mixture of binder and pigment. In yet another embodiment, there is a method for manufacturing coated paperboard. The method includes applying a first aqueous barrier coating over a first side of a recycled paperboard substrate. The first aqueous barrier coating is formed from a mixture of binder and pigment. Other embodiments of the disclosed coated paperboard and method for manufacturing a coated paperboard will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-section of a portion of a coated paperboard according to an exemplary embodiment of the present description. DETAILED DESCRIPTION FIG. 1 is a cross-section of a portion of a coated paperboard 2 according to an exemplary embodiment of the present description. As shown in FIG. 1, the coated paperboard 2 includes a recycled paperboard substrate 4 having a first side 6 and a second side 8, a first aqueous barrier coating 10 applied over the first side 6, and a second aqueous barrier coating 12 applied over the first aqueous barrier coating 10. According to another exemplary embodiment of the present description, the second aqueous barrier coating 12 may be omitted. The coated paperboard 2 may further include a basecoat 14 between the first side 6 of the recycled paperboard substrate 4 and the first aqueous barrier coating 10. The coated paperboard 2 may further include additional layers on the first side 6 of the recycled paperboard substrate 4, such as, for example, a third aqueous barrier coating applied over the second aqueous barrier coating 12. The third aqueous barrier coating may have the same or different characteristics than the first aqueous barrier coating 10 and the second aqueous barrier coating 12. Additionally, the coated paperboard 2 may further include additional layers on the second side 8 of the recycled paperboard substrate 4. These additional layers may the same or different layers than the first side 6 of the recycled paperboard substrate 4. Recycled paperboard substrates are produced from fibers recovered from paper waste, thereby providing for a sustainable paperboard product. In an expression, the recycled paperboard substrate 4 of the present description is produced from at least 1%, by weight, recovered fibers. In another expression, the recycled paperboard substrate 4 of the present description is produced from at least 5%, by weight, recovered fibers. In yet another expression, the recycled paperboard substrate 4 of the present description is produced from at least 10%, by weight, recovered fibers. In yet another expression, t