Silver-containing antimicrobial articles and methods of manufacture

• US 20070166399A1
• Filed: 01/13/2006
• Published: 07/19/2007
• Est. Priority Date: 01/13/2006
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Burton, Scott, Holm, David
• Application Number:
  US11/331,867
• Publication Number:
  US 20070166399A1
• Time in Patent Office: Days
• US Class Current: 424/618
• CPC Class Codes: A01N 2300/00 Combinations or mixtures of active ingredients covered by classes A01N27/00 - A01N65/48 with other active or formulation relevant ingredients, e.g. specific carrier materials or surfactants, covered by classes A01N25/00 - A01N65/48
• CPC Class Codes: A01N 25/34 Shaped forms, e.g. sheets, not provided for in any other sub-group of this main group
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: A61K 33/38 Silver; Compounds thereof
• CPC Class Codes: A61L 15/18 containing inorganic materials
• CPC Class Codes: A61L 15/46 Deodorants or malodour counteractants, e.g. to inhibit the formation of ammonia or bacteria
• CPC Class Codes: A61L 2/08 Radiation
• CPC Class Codes: A61L 2/238 Metals or alloys, e.g. oligodynamic metals
• CPC Class Codes: A61L 2300/104 Silver, e.g. silver sulfadiazine
• CPC Class Codes: A61L 2300/404 Biocides, antimicrobial agents, antiseptic agents
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61P 31/00 Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics

Abstract

A silver composition comprising silver sulfate, methods of making antimicrobial articles, particularly packaged antimicrobial articles, methods of whitening antimicrobial articles, and packaged antimicrobial articles.

Claims

1. A method of making a packaged antimicrobial article, the method comprising:

preparing a composition comprising silver sulfate;

coating the silver sulfate composition on a substrate;

drying the coated substrate to form an antimicrobial article;

placing the antimicrobial article in packaging material having a volatile organic content of no greater than 100 mg per square meter; and

sealing the packaging material with the antimicrobial article therein.

2. The method of claim 1 further comprising irradiating the antimicrobial article after the packaging material is sealed.

3. The method of claim 2 wherein irradiating comprises irradiating with gamma radiation and/or electron beam radiation.

4. The method of claim 2 wherein drying the coated substrate occurs at a temperature that causes the silver sulfate composition to develop a color other than a whitish color, and further wherein the antimicrobial article is color stable after irradiation.

5. The method of claim 1 wherein the substrate is a silver nitrate oxidizable substrate.

6. The method of claim 5 wherein drying the coated substrate occurs at a temperature that causes the silver sulfate composition to develop a yellowish color due to the formation of silver in the zero valence state, and further wherein the antimicrobial article is color stable after irradiation.

7. The method of claim 1 wherein the substrate comprises a cellulosic material.

8. The method of claim 6 wherein the substrate comprises cotton.

9. The method of claim 1 wherein the substrate is a nonwoven gauze, a woven gauze, a porous film, a nonporous film, a knitted fabric, a foam, or a hydrocolloid.

10. The method of claim 1 wherein the substrate comprises a material selected from the group consisting of polyester, nylon, polyethylene, polypropylene, polyacrylonitrile, polyvinylidene difluoride, polytetrafluoroethylene, polyoxymethylene, polyvinyl chloride, polycarbonate, styrene-ethylenebutylene-styrene elastomer, styrene-butylene-styrene elastomer, styrene-isoprene-styrene elastomer, and combinations thereof.

11. The method of claim 1 wherein drying the coated substrate occurs at a temperature of less than 190 °

C.

12. The method of claim 1 wherein stabilizing agents are present in the composition in an amount of less than 100 ppm.

13. The method of claim 1 wherein the antimicrobial article is maintained in an environment of no more than 50% RH at room temperature.

14. The method of claim 13 wherein the antimicrobial article is maintained in an environment of no more than 30% RH at room temperature.

15. The method of claim 14 wherein drying the coated substrate occurs at a temperature that causes the silver sulfate composition to develop a color other than a whitish color, and further wherein the antimicrobial article is color stable during and after irradiation.

16. The method of claim 1 wherein drying the coated substrate occurs at a temperature that causes the silver sulfate composition to develop a whitish color, further wherein activated carbon is present in the packaging, and further wherein the antimicrobial article is color stable during and after irradiation.

17. The method of claim 1 wherein the packaging material has an oxygen permeability of less than 0.01 cubic centimeter per 645 square centimeters per 24 hours.

18. The method of claim 1 wherein the packaging material has a moisture vapor transmission rate of less than 0.01 gram per 645 square centimeters per 24 hours.

19. The method of claim 1 wherein the silver sulfate composition further comprises silver compounds other than silver sulfate.

20. The method of claim 19 wherein the silver compounds are selected from the group consisting of silver oxide, silver nitrate, silver acetate, silver citrate, silver chloride, silver lactate, silver phosphate, silver stearate, silver thiocyanate, silver carbonate, silver saccharinate, silver anthranilate and combinations thereof.

21. The method of claim 1, further comprising silver metal.

22. The method of claim 20 wherein silver in the zero-valent state comprises less than 20 wt % of the composition based on the total weight of the silver compounds of the composition.

23. The method of claim 1 wherein the silver sulfate is present in an amount of at least 60 wt % of the composition based on the total weight of the silver compounds of the composition.

24. The method of claim 1 wherein the silver sulfate composition is essentially free of any acid.

25. A packaged antimicrobial article made by the method of claim 1.

26. A packaged antimicrobial article, comprising:

an antimicrobial article comprising a substrate coated with a silver sulfate composition; and

packaging having the antimicrobial article sealed therein;

wherein the packaging comprises material having a volatile organic content of no greater than 100 mg per square meter.

27. The packaged article of claim 26 wherein the silver compounds are selected from the group consisting of silver oxide, silver nitrate, silver acetate, silver citrate, silver chloride, silver lactate, silver phosphate, silver stearate, silver thiocyanate, silver carbonate, silver saccharinate, silver anthranilate and combinations thereof.

28. The packaged article of claim 26 wherein the dried coated substrate further comprises silver metal in the zero-valent state and has a yellowish color.

29. The packaged article of claim 28 which is color stable after gamma or e-beam irradiation.

30. The packaged article of claim 28 which is color stable during and after gamma or e-beam irradiation.

31. The packaged article of claim 26 which has a whitish color and activated carbon sealed with the article within the packaging.

32. The packaged article of claim 26 wherein the substrate is a silver nitrate oxidizable substrate.

33. The packaged article of claim 26 wherein the substrate comprises a cellulosic material.

34. The packaged article of claim 33 wherein the substrate comprises cotton.

35. The packaged article of claim 26 wherein the substrate is a nonwoven gauze, a woven gauze, a porous film, a nonporous film, a knitted fabric, foam, or a hydrocolloid.

36. The packaged article of claim 26 wherein the substrate comprises a material selected from the group consisting of polyester, nylon, polyethylene, polypropylene, polyacrylonitrile, polyvinylidene difluoride, polytetrafluoroethylene, polyoxymethylene, polyvinyl chloride, polycarbonate, styrene-ethylenebutylene-styrene elastomer, styrene-butylene-styrene elastomer, styrene-isoprene-styrene elastomer, and combinations thereof.

37. The packaged article of claim 26 comprising stabilizing agents in an amount less than 100 ppm.

38. The packaged article of claim 26 wherein the antimicrobial article is maintained in an environment of no more than 50% RH at room temperature.

39. The packaged article of claim 38 wherein the antimicrobial article is maintained in an environment of no more than 30% RH at room temperature.

40. The packaged article of claim 39 wherein the article has a yellowish color, and further wherein the antimicrobial article is color stable during and after irradiation.

41. The packaged article of claim 26 wherein the silver sulfate composition further comprises silver compounds other than silver sulfate.

42. The packaged article of claim 26 wherein the packaging comprises material having an oxygen permeability of less than 0.01 cubic centimeter per 645 square centimeters per 24 hours.

43. The packaged article of claim 26 wherein the packaging comprises material having a moisture vapor transmission rate of less than 0.01 gram per 645 square centimeters per 24 hours.

44. A method of whitening at least a portion of an antimicrobial article, the method comprising:

providing a packaged antimicrobial article having at least a portion colored other than white, wherein the article comprises a substrate coated with a silver salt composition comprising at least a portion of the silver in the zero-valent state, and wherein the antimicrobial article is sealed within packaging comprising material having a volatile organic content of greater than 100 mg per square meter; and

irradiating the packaged antimicrobial article to whiten at least a portion of the antimicrobial article.

45. The method of claim 44 wherein the silver salt composition comprises silver sulfate, silver nitrate, silver acetate, silver citrate, silver chloride, silver lactate, silver phosphate, silver stearate, silver thiocyanate, silver carbonate, silver saccharinate, silver anthranilate or combinations thereof.

46. The method of claim 45 wherein the silver salt composition comprises silver sulfate.

47. The method of claim 44 wherein irradiating comprises irradiating with gamma radiation and/or electron beam radiation.

48. The method of claim 44 wherein the substrate is a silver nitrate oxidizable substrate.

49. The method of claim 44 wherein the substrate comprises a cellulosic material.

50. A packaged antimicrobial article made by the method of claim 44.