Antimicrobial resin cured rubber articles and prevulcanized compositions

• US 6,846,871 B2
• Filed: 04/25/2003
• Issued: 01/25/2005
• Est. Priority Date: 04/25/2003
• Status: Expired due to Fees

• Current Assignee: Milliken & Company
• Original Assignee: Milliken & Company
• Inventors: Patel, Bhawan, Morris, David L.
• Primary Examiner(s): Cheung, William K.
• Application Number:
  US10/424,025
• Publication Number:
  US 20040214939A1
• Time in Patent Office: 641 Days
• Field of Search: 524/440, 524/450, 524/493, 526/335, 523/122
• US Class Current: 524/440
• CPC Class Codes: C08K 3/015 Biocides macromolecular substances as carriers for biocide material A01N25/10
• CPC Class Codes: C08K 3/08 Metals
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08L 21/00 Compositions of unspecified rubbers

Abstract

This invention relates to certain non-silicone resin cured rubber articles that are made from at least a majority by weight of non-silicone vulcanized rubber that include silver-based compounds to provide highly desirable long-term antimicrobial characteristics within the cured rubber articles. Such articles are in either solid or blown (foam or sponge) state (or combinations of both in multilayered forms) and can be utilized in a variety of different applications. This invention encompasses the presence of non-sulfur-based curing systems and agents, such as resin curing, that permit vulcanization and do not irreversibly bind silver ions thereto, thereby resulting in long-term antimicrobial performance of the ultimate rubber article itself. This invention also encompasses certain non-silicone pre-vulcanized raw rubber formulations made from at least a majority by weight of non-silicone rubber that include silver-based components to provide highly desirable long-term antimicrobial characteristics within the ultimate resin cured rubber articles made therefrom.

Claims

1. A dimensionally stable rubber article comprising at least one silver-based antimicrobial compound and at least one resin curing compound, wherein all of said resin curing compound present within said rubber article does not include a molar ratio of more than about 0.000000001:

1 to about 0.25;

1 of sulfur to silver ions, wherein said rubber article exhibits log kill rates in accordance with ATCC Test Method 6538 for Staphylococcus aureus and ATCC Test Method 4352 for Klebsiella pneumoniae of at least 1.0 each after 24 hours exposure at room temperature, and wherein said article optionally comprises at least one silver ion release control additive and at least one antifungal additive other than said silver-based antimicrobial compound.

2. The rubber article of claim 1 wherein said article exhibits log kill rates for Staphylococcus aureus and Klebsiella pneumoniae of at least 2.0 each after 24 hours exposure at room temperature.

3. The rubber article of claim 1 wherein said rubber article is comprised of a majority of rubber selected from the group consisting of nitrile rubber, nitrile butadiene rubber (NBR), styrene butadiene rubber, natural rubber, chloroprene rubber, polychloroprene rubber, ethylene propylene rubber, ethylene propylene diene monomer rubber, fluoroelastomer rubber, polyurethane rubber, butyl rubber, halogenated butyl rubber, isoprene rubber, epichlorohydrin rubber, polyacrylate rubber, chlorinated polyethylene rubber, hydrogenated NBR, carboxylated NBR, polybutadiene rubber, and any mixture thereof.

4. The rubber article of claim 1 wherein said silver-based antimicrobial compound is selected from the group consisting of elemental silver, silver oxides, silver salts, silver ion exchange compounds, silver zeolites, silver glasses, and any mixtures thereof.

5. The rubber article of claim 2 wherein said silver-based antimicrobial compound is selected from the group consisting of elemental silver, silver oxides, silver salts, silver ion exchange compounds, silver zeolites, silver glasses, and any mixtures thereof.

6. The rubber article of claim 1 wherein said at least one silver ion control release additive is present.

7. The rubber article of claim 1 wherein said antifungal additive other than said silver-based antimicrobial compound is present.

8. The rubber article of claim 6 wherein said at least one silver ion control release additive is selected from the group consisting of fillers, oils, pigments, salts, antistatic agents, and any mixtures thereof.

9. The rubber article of claim 8 wherein said at least one silver ion control release additive is a hydrophilic filler selected from the group consisting of silica, stearates, and any mixtures thereof.

10. The rubber article of claim 8 further comprising at least one hydrophilic all selected from the group consisting or paraffinic oil, phthalate oil, and any mixtures thereof.

11. The rubber article of claim 3 wherein said rubber article is comprised of butyl rubber.

12. The rubber article of claim 3 wherein said rubber article is comprised of halogenated butyl rubber.

20. The rubber article of claim 1 wherein said article is a mat structure.

13. A dimensionally stable rubber-containing article comprising at least one silver-based antimicrobial agent and at least one resin curing compound, wherein all of said resin curing compound present within said rubber article does not include a molar ratio of more than about 0.000000001:

1 to about 0.25;

1 of sulfur to silver ions, wherein said article exhibits antifungal properties such that said article exhibits at least 60% inhibition in accordance with Test Method ISO 846 of Aspergillus niger ATCC 6275 for at least 10 days at 30°

C. and at greater than 90% humidity, and wherein said article optionally comprises at least one silver ion release control additive and at least one antifungal additive other than said sliver-based antimicrobial compound.

14. The rubber article of claim 13 wherein said silver-based antimicrobial compound is selected from the group consisting of elemental silver, silver oxides, sliver salts, silver ion exchange compounds, silver zeolites, silver glasses, and any mixtures thereof.

15. The rubber article of claim 13 wherein said at least one silver ion control release additive is present.

16. The rubber article of claim 13 wherein said antifungal additive other than said silver-based antimicrobial compound is present.

17. The rubber article of claim 13 wherein said at least one silver ion control release additive is selected from the group consisting of fillers, oils, pigments, salts, antistatic agents, and any mixtures thereof.

18. The rubber article of claim 17 wherein said at least one silver ion control release additive is a hydrophilic filler selected from the group consisting of silica, stearates, and any mixtures thereof.

19. The rubber article of claim 17 further comprising at least one hydrophilic oil selected from the group consisting of paraffinic oil, phthalate oil, and any mixtures thereof.

21. The rubber article of claim 13 wherein said article is a mat structure.

22. A pre-vulcanized rubber formulation comprising at least one rubber constituent, the majority of which must be a non-silicone rubber, at least one silver-based antimicrobial compound and at least one resin curing compound, wherein all of said resin curing compound present within said formulation does not include an appreciable amount of sulfur-based compounds, and wherein said rubber formulation optionally comprises at least one blowing agent, at least one silver ion release control additive, and at least one antifungal additive other than said silver-based antimicrobial compound.

23. The rubber formulation of claim 22 wherein said rubber constituent is selected from the group consisting of nitrile rubber, nitrile butadiene rubber, styrene butadiene rubber, natural rubber, chloroprene rubber, polychloroprene rubber, ethylene propylene rubber, ethylene propylene diene monomer rubber, fluoroelastomer rubber, polyurethane rubber, butyl rubber, halogenated butyl rubber, chlorobutyl rubber, bromobutyl rubber, isoprene rubber, epichlorohydrin rubber, polyacrylate rubber, chlorinated polyethylene rubber, hydrogenated NBR, carboxylated NBR, polybutadiene rubber, and any mixture thereof.

24. The rubber formulation of claim 22 wherein said silver-based antimicrobial compound is selected from the group consisting of elemental silver, silver oxides, silver salts, silver ion exchange compounds, silver zeolites, silver glasses, and any mixtures thereof.

25. The rubber formulation of claim 22 wherein said at least one blowing agent is present.

26. The rubber formulation of claim 22 wherein said at least one silver ion control release additive is present.

27. The rubber formulation of claim 22 wherein said antifungal additive other than said silver-based antimicrobial compound is present.

28. The rubber formulation of claim 26 wherein said at least one silver ion control release additive is selected from the group consisting of fillers, oils, pigments, salts, antistatic agents, and any mixtures thereof.

29. The rubber formulation of claim 28 wherein said at least one silver ion control release additive is a hydrophilic filler selected from the group consisting of silica, stearates, and any mixtures thereof.

30. The rubber formulation of claim 28 further comprising at least one oil selected from the group consisting of paraffinic oil, phthalate oil, and any mixtures thereof.

31. The rubber formulation of claim 23 wherein said rubber constituent is polychloroprene rubber.

32. The rubber formulation of claim 23 wherein said rubber constituent is natural rubber.

33. The rubber formulation of claim 23 wherein said rubber constituent is ethylene propylene diene monomer rubber.

34. The rubber formulation of claim 23 wherein said rubber constituent is nitrile rubber.

35. The rubber formulation of claim 23 wherein said rubber constituent is styrene butadiene rubber.

36. The rubber formulation of claim 23 wherein said rubber constituent is butyl rubber.

37. The rubber formulation of claim 23 wherein said rubber constituent is bromobutyl rubber.

38. A method of producing a rubber article exhibiting long-lasting, regenerable antimicrobial characteristics, comprising the steps of compounding together the unvulcanized rubber formulation of claim 22, molding said rubber formulation into a preselected shape, and vulcanizing said rubber formulation under high pressure and exposure to high temperature.

39. A method of producing a rubber article exhibiting long-lasting, regenerable antimicrobial characteristics, comprising the steps of compounding together the unvulcanized rubber formulation of claim 23, molding said rubber formulation into a preselected shape, and vulcanizing said rubber formulation under high pressure and exposure to high temperature.

40. A method of producing a rubber article exhibiting long-lasting, regenerable antimicrobial characteristics, comprising the steps of compounding together the unvulcanized rubber formulation of claim 25, molding said rubber formulation into a preselected shape, and vulcanizing said rubber formulation under high pressure and exposure to high temperature.

41. A method of producing a rubber article exhibiting long-lasting, regenerable antimicrobial characteristics, comprising the steps of compounding together the unvulcanized rubber formulation of claim 26, molding said rubber formulation into a preselected shape, and vulcanizing said rubber formulation under high pressure and exposure to high temperature.

42. A method of producing a rubber article exhibiting long-lasting, regenerable antimicrobial characteristics, comprising the steps of compounding together the unvulcanized rubber formulation of claim 27, molding said rubber formulation into a preselected shape, and vulcanizing said rubber formulation under high pressure and exposure to high temperature.