Method for treating a substrate

• US 8,349,443 B2
• Filed: 05/29/2008
• Issued: 01/08/2013
• Est. Priority Date: 02/23/2006
• Status: Active Grant

• Current Assignee: Westrock mwv, llc (WestRock Company)
• Original Assignee: Meadwestvaco (WestRock Company)
• Inventors: Fugitt, Gary P., Ginther, Scott E., Stolarz, John W., Carlson, Robert W., Metzler, Steven P., Green, Terrell J., McGrew, Stanley H. Jr.
• Primary Examiner(s): Vo, Hai
• Application Number:
  US12/156,049
• Publication Number:
  US 20080254298A1
• Time in Patent Office: 1,685 Days
• Field of Search: 428/319.3, 428/319.7, 428/319.9, 428/315.5, 428/315.7
• US Class Current: 428/315.7
• CPC Class Codes: B05D 2203/22 Paper or cardboard
• CPC Class Codes: B05D 2252/02 of indefinite length
• CPC Class Codes: B05D 2401/20 Aqueous dispersion or solution
• CPC Class Codes: B05D 3/0209 Multistage baking
• CPC Class Codes: B05D 3/0254 After-treatment
• CPC Class Codes: B05D 3/12 by mechanical means
• CPC Class Codes: D21H 19/16 comprising curable or polymerisable compounds D21H19/24 takes precedence
• CPC Class Codes: D21H 19/34 comprising cellulose or derivatives thereof
• CPC Class Codes: D21H 23/56 Rolls D21H23/38 takes precedence
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/249979 Specified thickness of void-containing component [absolute or relative] or numerical cell dimension
• CPC Class Codes: Y10T 428/31 Surface property or characteristic of web, sheet or block

Abstract

A method for treating a substrate is described. In accordance with one aspect, the method includes applying a polymer coating to a substrate, and bringing the polymer coating into contact with a heated surface in a pressure nip while the coating is still in a wet state. Optionally the polymer coating may include a crosslinkable material, and a crosslinking agent may be used to promote crosslinking. The polymer coating replicates the heated surface. A product produced in accordance with the described method is also disclosed. The product is characterized by having subsurface voids within the coating.

Claims

1. A product, comprising:

a substrate; and

a first coating on the substrate,

wherein the first coating includes a water soluble polymer,

wherein the first coating includes a surface and at least 50% of the first coating surface has voids having a transverse dimension of at least 6 microns,

wherein the voids are defined by the coating and substantially all of the voids are formed under the surface of the coating, and

wherein the first coating surface has a Sheffield Smoothness less than about 200 units.

2. The product of claim 1, wherein the first coating contains essentially no elastomeric material.

3. The product of claim 1, wherein the substrate includes at least one of cellulose, paper, paperboard, fabric, fibrous material, porous material, porous film, or polylactic acid.

4. The product of claim 1, wherein the water soluble polymer includes a cross linkable polymer.

5. The product of claim 1, wherein the first coating includes a cross linking agent.

6. The product of claim 5, wherein the cross linking agent comprises at least one of borax, borates, aldehydes, ammonium salts, calcium compounds, and derivatives thereof.

7. The product of claim 1, wherein the first coating includes by dry weight at least about 60% water soluble polymer and up to 10% release agent.

8. The product of claim 1, wherein the water soluble polymer includes at least one of starch, waxy maize, protein, polyvinyl alcohol, casein, gelatin, and alginate.

9. The product of claim 8, wherein the protein comprises soybean protein.

10. The product of claim 1, wherein the release agent includes at least one of wax, fatty acid metal soap, metal stearates, long chain alkyl derivatives, fatty esters, fatty amides, fatty amines, fatty acids, fatty alcohols, polymers, fluorinated compounds, fluorinated fatty acids, and combinations thereof.

11. The product of claim 10, wherein the wax comprises at least one of petroleum wax, vegetable wax, animal wax, and synthetic wax.

12. The product of claim 10, wherein the polymers comprise at least one of polyolefins, silicone polymers, fluoropolymers, and natural polymers.

13. The product of claim 1, further comprising a second coating on the first coating.

14. The product of claim 13, wherein the second coating includes at least one of pigments, binders, and fillers.

15. The product of claim 1, wherein the substrate comprises one of a web or a sheet.

16. The product of claim 1, wherein the Sheffield Smoothness is less than about 150 units.

17. The product of claim 1, wherein the first coating further includes a release agent.

18. The product of claim 1, wherein the transverse dimension is at least 11 microns.

19. A product, comprising:

a substrate; and

a first coating on the substrate,

wherein the first coating includes a water soluble polymer and essentially no elastomeric material,

wherein the first coating includes a surface and at least 50% of the first coating surface has voids having a transverse dimension of at least 6 microns,

wherein the voids are defined by the coating and substantially all of the voids are formed under the surface of the coating, and

wherein the first coating surface has a Sheffield Smoothness less than about 200 units.

20. The product of claim 19, wherein the substrate includes at least one of cellulose, paper, paperboard, fabric, fibrous material, porous material, porous film, or polylactic acid.

21. The product of claim 19, wherein the water soluble polymer includes a cross linkable polymer.

22. The product of claim 19, wherein the first coating includes a cross linking agent.

23. The product of claim 22, wherein the cross linking agent comprises at least one of borax, borates, aldehydes, ammonium salts, calcium compounds, and derivatives thereof.

24. The product of claim 19, wherein the first coating includes by dry weight at least about 60% water soluble polymer and up to 10% release agent.

25. The product of claim 24, wherein the release agent includes at least one of wax, fatty acid metal soap, metal stearates, long chain alkyl derivatives, fatty esters, fatty amides, fatty amines, fatty acids, fatty alcohols, polymers, fluorinated compounds, fluorinated fatty acids, and combinations thereof.

26. The product of claim 25, wherein the wax comprises at least one of petroleum wax, vegetable wax, animal wax, and synthetic wax.

27. The product of claim 25, wherein the polymers comprise at least one of polyolefins, silicone polymers, fluoropolymers, and natural polymers.

28. The product of claim 19, wherein the first coating includes at least one of starch, waxy maize, protein, polyvinyl alcohol, casein, gelatin, and alginate.

29. The product of claim 28, wherein the protein comprises soybean protein.

30. The product of claim 19, further comprising a second coating on the first coating.

31. The product of claim 30, wherein the second coating includes at least one of pigments, binders, and fillers.

32. The product of claim 19, wherein the substrate comprises one of a web or a sheet.

33. The product of claim 19, wherein the Sheffield Smoothness is less than about 150 units.

34. The product of claim 19, wherein the transverse dimension is at least 11 microns.