ANTIMICROBIAL, HYPOALLERGENIC, AND TARNISH-RESISTANT CU-BASED ALLOY AND RELATED METHODS THEREOF

• US 20190316228A1
• Filed: 04/16/2019
• Published: 10/17/2019
• Est. Priority Date: 04/16/2018
• Status: Active Grant

• Current Assignee: University of Virginia Patent Foundation (University of Virginia)
• Original Assignee: University of Virginia Patent Foundation (University of Virginia)
• Inventors: Hutchison, Michael J., Scully, John R.
• Granted Patent: US 11,155,899 B2
• Time in Patent Office: Days
• CPC Class Codes: A01N 59/06 Aluminium; Calcium; Magnesium; Compounds thereof
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: A01N 59/20 Copper
• CPC Class Codes: C22C 9/01 with aluminium as the next major constituent
• CPC Class Codes: C22C 9/02 with tin as the next major constituent

Abstract

Described herein are ternary alloys of copper (Cu), aluminum (Al) and tin (Sn). For example, the ternary alloys can comprise between about 0.5 weight percent (wt %) and about 5 wt % Al and between about 0.5 wt % and about 5 wt % Sn. The chemical composition of the alloys can be tailored such that the alloy maintains antimicrobial effect over time and is resistant to tarnish. The alloys are also hypoallergenic. Articles of manufacture, particularly those for use in medical facilities, comprising the alloy (e.g., as a surface layer) are also described, as are methods of reducing the incidence of microbial infection by providing surfaces comprising the alloy.

Claims

1. A copper (Cu) alloy comprising between about 0.5 weight percent (wt %) and about 5 wt % aluminum (Al), and between about 0.5 wt % and about 5 wt % tin (Sn), and the remainder copper and unavoidable impurities, wherein said Cu alloy is antimicrobial, tarnish-resistant and hypoallergenic.

2. The Cu alloy of claim 1, wherein the Cu alloy is a monophasic solid solution having a face-centered cubic (fcc) lattice structure.

3. The Cu alloy of claim 1, wherein the Cu alloy is tarnish-resistant under exposure to artificial perspiration for one week or more.

4. The Cu alloy of claim 3, wherein the surface of the Cu alloy has an optically transparent oxide layer that has a thickness of about 0.5 micrometer or less under exposure to artificial perspiration for one week or more.

5. The Cu alloy of claim 1, wherein release of Cu cations from the Cu alloy is continuous for at least one week or more.

6. The Cu alloy of claim 5, the Cu cation release is continuous in the presence of perspiration.

7. The Cu alloy of claim 1, wherein a 1.1 cm² surface of the Cu alloy has about a 100% killing efficiency for E. coli after 24 hours wherein the surface is contacted with about 2×

10⁶ colony forming units (CFU) of E. coli in the presence of an aerated solution of artificial perspiration with a volume of 200 mL or less.

8. The Cu alloy of claim 1, wherein the Cu alloy comprises between about 1 wt % Sn and about 5 wt % Sn and between about 1 wt % Al and about 4.5 wt % Al.

9. An article of manufacture comprising the Cu alloy of claim 1.

10. The article of manufacture of claim 9, wherein said article of manufacture is selected from the group consisting of a medical, veterinary, or dental device;

medical facility furniture;

a hand railing, a door or window handle or fitting;

a tray table;

a hospital room call button;

a chair or sofa;

a wheel chair;

a walker;

a cane or crutch;

automatic door push plates;

toilet safety rails;

carts;

sinks, sink handles;

drain control levers;

paper towel holders;

push buttons on air hand dryers;

drawer knobs, shower or bathtub grab bars;

towel bars;

toilet hardware;

light switches;

switch plates;

thermostat covers and controls;

telephone handsets;

instrument handles;

food trays;

instrument trays;

bedpans;

exercise equipment;

physical therapy equipment;

medical chart holders;

laundry hampers;

television controls;

a computer mouse;

a computer keyboard;

a personal digital assistant;

toothbrush holders;

pens;

ATM machines;

gym lockers;

elevator handrails or control buttons;

soap holders;

soap dispensers;

toilet paper dispensers;

bracelets;

water fountain knobs and/or buttons;

kitchen cabinet door handles;

microwave handles;

refrigerator handles;

stove top control buttons;

play area equipment;

smart phone covers; and

vending machines.

11. A method of reducing the incidence of microbial infection, the method comprising providing a surface comprising a copper (Cu) alloy, wherein said Cu alloy is antimicrobial, tarnish-resistant and hypoallergenic, further wherein said Cu alloy comprises copper, between about 0.5 weight percent (wt %) and about 5 wt % aluminum (Al), and between about 0.5 wt % and about 5 wt % tin (Sn), and is free of nickel (Ni) and zinc (Zn).

12. The method of claim 11, wherein the Cu alloy is a monophasic solid solution having a face-centered cubic (fcc) lattice structure.

13. The method of claim 11, wherein the Cu alloy is tarnish-resistant under exposure to artificial perspiration for one week or more.

14. The method of claim 13, wherein the surface of the Cu alloy has an optically transparent oxide layer that has a thickness of about 0.5 micrometer or less under exposure to artificial perspiration for one week or more.

15. The method of claim 11, wherein release of Cu cations from the Cu alloy is continuous for at least one week or more.

16. The method of claim 15, wherein the release is continuous in the presence of perspiration.

18. The method of claim 11, wherein the Cu alloy comprises between about 1 wt % Sn and about 5 wt % Sn and between about 1 wt % Al and about 4.5 wt % Al.

19. The method of claim 11, wherein the Cu alloy is selected from the group consisting of Cu-1 wt % Al-1 wt % Sn, Cu-1 wt % Al-5 wt % Sn, and Cu-5 wt % Al-1 wt % Sn.

20. The method of claim 11, wherein the providing comprises adding a coating layer comprising the Cu alloy to a surface present in a public space.

21. The method of claim 20, wherein the public space is a medical facility, a space associated with public transportation, a hospital, or an urgent-care facility.

22. The method of claim 11, wherein the providing comprises providing a piece of furniture, a hand railing, a room fitting, or a medical, veterinary, or dental device comprising the Cu alloy.

23. The method of claim 11, wherein the surface is part of an article selected from the group consisting of a medical, veterinary, or dental device;

medical facility furniture;

a hand railing, a door or window handle or fitting;

a tray table;

a hospital room call button;

a chair or sofa;

a wheel chair;

a walker;

a cane or crutch;

automatic door push plates;

toilet safety rails;

carts;

sinks, sink handles;

drain control levers;

paper towel holders;

push buttons on air hand dryers;

drawer knobs, shower or bathtub grab bars;

towel bars;

toilet hardware;

light switches;

switch plates;

thermostat covers and controls;

telephone handsets;

instrument handles;

food trays;

instrument trays;

bedpans;

exercise equipment;

physical therapy equipment;

medical chart holders;

laundry hampers;

television controls;

a computer mouse;

a computer keyboard;

a personal digital assistant;

toothbrush holders;

pens;

ATM machines;

gym lockers;

elevator handrails or control buttons;

soap holders;

soap dispensers;

toilet paper dispensers;

bracelets;

water fountain knobs and/or buttons;

kitchen cabinet door handles;

microwave handles;

refrigerator handles;

stove top control buttons;

play area equipment;

smart phone covers; and

vending machines.

17. The method of claim 17, wherein a 1.1 cm² surface of the Cu alloy has about a 100% killing efficiency for E. coli after 24 hours when said surface is contacted with about 2×

10⁶ colony forming units (CFU) of E. coli in the presence of an aerated solution of artificial perspiration with a volume of 200 mL or less.