Coated, antimicrobial, chemically strengthened glass and method of making

• US 8,753,744 B2
• Filed: 11/20/2013
• Issued: 06/17/2014
• Est. Priority Date: 08/06/2010
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Borrelli, Nicholas Francis, Morse, David Lathrop, Senaratne, Wageesha, Verrier, Florence, Wei, Ying
• Primary Examiner(s): SAMPLE, DAVID R
• Application Number:
  US14/085,248
• Publication Number:
  US 20140072783A1
• Time in Patent Office: 209 Days
• Field of Search: None
• US Class Current: 428/410
• CPC Class Codes: A01N 25/08 containing solids as carriers or diluents
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• CPC Class Codes: C03C 17/30 with silicon-containing compounds
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 21/005 to introduce in the glass such metals or metallic ions as Ag, Cu
• CPC Class Codes: C03C 2204/02 Antibacterial glass, glaze or enamel
• CPC Class Codes: C03C 2204/04 Opaque glass, glaze or enamel
• CPC Class Codes: C03C 2217/76 Hydrophobic and oleophobic coatings
• CPC Class Codes: C03C 3/083 containing aluminium oxide or an iron compound
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/093 containing zinc or zirconium
• CPC Class Codes: C03C 3/095 containing rare earths
• CPC Class Codes: C03C 4/00 Compositions for glass with special properties
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/27 Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.]
• CPC Class Codes: Y10T 428/273 of coating
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]
• CPC Class Codes: Y10T 428/31612 As silicone, silane or siloxane

Abstract

The disclosure is directed to a chemically strengthened glass having antimicrobial properties and to a method of making such glass. In particular, the disclosure is directed to a chemically strengthened glass with antimicrobial properties and with a low surface energy coating on the glass that does not interfere with the antimicrobial properties of the glass. The antimicrobial has an Ag ion concentration on the surface in the range of greater than zero to 0.047 μg/cm². The glass has particular applications as antimicrobial shelving, table tops and other applications in hospitals, laboratories and other institutions handling biological substances, where color in the glass is not a consideration.

Claims

1. An antimicrobial, chemically strengthened glass comprising:

a glass article;

a compressive stress layer in the glass article extending to a first selected depth in the glass article; and

an antimicrobial Ag+ region extending from the surface of the glass article to a second selected depth in the glass article, the Ag+ region having a plurality of Ag⁺¹ ions,

wherein the compressive stress in the compressive stress layer is at least 250 MPa, and the concentration of the plurality of Ag⁺¹ ions on the surface of the glass article is in the range of greater than zero to less than or equal to 0.047 μ

g/cm².

2. The antimicrobial, chemically strengthened glass according to claim 1, wherein the glass article further comprises a low surface energy coating on the surface of the glass article that allows water molecules to contact the plurality of Ag⁺¹ ions on the surface of the glass.

3. The antimicrobial, chemically strengthened glass according to claim 1, wherein the surface of the glass article exhibits a Log Reduction value of greater than 1 for an antimicrobial test incubation of an hour for each of at least two microbial species.

4. The antimicrobial, chemically strengthened glass according to claim 1, wherein the surface of the glass article exhibits a Log Reduction value of greater than 4 for an antimicrobial test incubation of six hours for at least one microbial species.

5. The antimicrobial, chemically strengthened glass according to claim 1, wherein the surface of the glass articles exhibits a Log Reduction value of greater than 5 for an antimicrobial test incubation of six hours for at least one microbial species.

6. The antimicrobial, chemically strengthened glass according to claim 1, wherein the concentration of the plurality of Ag⁺¹ ions on the surface of the glass article is in the range of 0.005 μ

g/cm² to 0.035 μ

g/cm² and the surface of the glass article is non-cytotoxic.

7. The antimicrobial, chemically strengthened glass according to claim 1, wherein the concentration of the plurality of Ag⁺¹ ions on the surface of the glass article is in the range of 0.01 μ

g/cm² to 0.035 μ

g/cm² and the surface of the glass article is non-cytotoxic.

8. The antimicrobial, chemically strengthened glass according to claim 1, wherein the concentration of the plurality of Ag⁺¹ ions on the surface of the glass article is in the range of 0.015 μ

g/cm² to 0.030 μ

g/cm² and the surface of the glass article is non-cytotoxic.

9. The antimicrobial, chemically strengthened glass according to claim 1, wherein the compressive stress in the compressive stress layer is at least 500 MPa.

10. The antimicrobial, chemically strengthened glass according to claim 2, wherein the low surface energy coating has a terminal perfluorinated moiety and a thickness in the range of 0.5 nm to 20 nm, and further wherein the coating is selected from the group consisting of silanes having a general formula of A_x-Si—

B₄, where A is perfluoroalkyl R_F—

, perfluoroalkyl terminated perfluoropolyether, perfluoroalkyl-alkyl, copolymers of fluoroalkene silanes and alkene silanes, and mixtures of fluoroalkylsilanes and hydrophilic silanes, B is Cl, acetoxy [CH₃—

C(O)—

O—

] or alkoxy, and x=1 or 2.

11. The antimicrobial, chemically strengthened glass according to claim 10, wherein the low surface energy coating further comprises a skeletal chain of (a) carbon atoms or (b) a combination of carbon and oxygen atoms, and further wherein the coating comprises a skeletal chain length in the range of 1 nm to 20 nm, the length defined from the silicon atom to the terminal perfluorinated moiety.

12. The antimicrobial, chemically strengthened glass according to claim 2, wherein the low surface energy coating is a perfluoroalkyl alkoxy silane of formula (R_F1)_x—

Si(OR)_4-x, where x=1 or 2, R_F1 moiety is a perfluoroalkyl group having a carbon chain length in the range of 16-130 carbon atoms, and OR is acetoxy, —

OCH₃ or OCH₂H₃.

13. The antimicrobial, chemically strengthened glass according to claim 2, wherein the low surface energy coating is a perfluoropolyether alkoxy silane of formula (RO)_4-z—

Si—

[(CH₂)₃—

OCF₂—

CF₂—

[OCF₂—

CF₂—

CF₂]_n—

F]_z, where z=1 or 2, n is an integer sufficient to provide that [(CH₂)₃—

OCF₂—

CF₂—

[OCF₂—

CF₂—

CF₂]_n—

F] has a chain length in the range of 2 nm to 20 nm, and RO is CH₃O—

, CH₃—

CH₂O—

, or CH₃C(O)O—

.

14. The antimicrobial, chemically strengthened glass according to claim 2, wherein the low surface energy coating is a perfluoroalkyl alkyl alkoxy silane of formula (RO)_4-z—

Si—

[(CH₂)_x—

(CF₂)_y—

CF₃]_z, where x and y are integers whose sum is sufficient to provide that [(CH₂)_x—

(CF₂)_y—

CF₃] has a chain length in the range of 2 nm to 20 nm, with the provision that y≧

x, z=1 or 2, and RO is CH₃O—

, CH₃—

CH₂O—

, or CH₃C(O)O—

.

15. The antimicrobial, chemically strengthened glass according to claim 10, wherein the low surface energy coating comprises a plurality of coating domains on the surface of the glass article, the plurality of coating domains having a thickness in the range of 0.5 nm to 10 nm, and further wherein the surface of the glass article is capable of antimicrobial action in the presence the plurality of coating domains.

16. The antimicrobial, chemically strengthened glass according to claim 10, wherein the low surface energy coating is a continuous coating having a thickness in the range of 0.5 nm to 10 nm over the surface of the glass article, and further wherein the surface of the glass article is capable of antimicrobial action in the presence of the coating.

17. The antimicrobial, chemically strengthened glass according to claim 10, wherein the low surface energy coating has a thickness in the range of 1 nm to 5 nm.

18. The antimicrobial, chemically strengthened glass according to claim 1, wherein the composition of the glass article is selected from the group consisting of soda lime glass, alkali aluminosilicate glass and alkali aluminoborosilicate glass.

19. The antimicrobial, chemically strengthened glass according to claim 1, wherein the composition of the glass article is substantially lithium free and selected from the group consisting of:

(a) 60-70 mol % SiO₂;

6-14 mol % Al₂O₃;

0-15 mol % B₂O₃;

0-15 mol % Li₂O;

0-20 mol % Na₂O;

0-10 mol % K₂O;

0-8 mol % MgO;

0-10 mol % CaO;

0-5 mol % ZrO₂;

0-1 mol % SnO₂;

0-1 mol % CeO₂;

less than 50 ppm As₂O₃; and

less than 50 ppm Sb₂O₃, wherein 12 mol % Na₂O+K₂O≦

20 mol % and 0 mol %MGO+CaO≦

10 mol %;

(b) 64 mol %≦

SiO₂≦

68 mol %;

12 mol %≦

Na₂O≦

16 mol %;

8 mol %≦

Al₂O₃≦

12 mol %;

0 mol %≦

B₂O₃≦

3 mol %;

2 mol %≦

K₂O≦

5 mol %;

4 mol %≦

MgO≦

6 mol %; and

0 mol %≦

CaO≦

5 mol %, wherein 66 mol %≦

SiO₂+B₂O₃+CaO≦

69 mol %, Na₂O+K₂O+B₂O₃+MgO+CaO+SrO≦

10 mol %;

5 mol %≦

MgO+CaO+SrO≦

8 mol %, (Na₂O+B₂O₃)—

Al₂O₃≦

2 mol %;

2 mol %≦

Na₂O—

Al₂O₃≦

6 mol %; and

4 mol %≦

(Na₂O+K₂O)—

Al₂O₃≦

10 mol %;

(c) 61 mol %≦

SiO₂≦

75 mol %;

9 mol %≦

Na₂O≦

21 mol %;

7 mol %≦

Al₂O₃≦

15 mol %;

0 mol %≦

B₂O₃≦

12 mol %;

0 mol %≦

K₂O≦

4 mol %;

0 mol %≦

MgO 7≦

mol %; and

0 mol %≦

CaO≦

mol %;

(d) 50 mol %≦

SiO₂≦

70 mol %;

8 mol %≦

Na₂O≦

16 mol %;

9 mol %≦

Al₂O₃≦

17 mol %;

2 mol %≦

B₂O₃≦

12 mol %;

0 mol %≦

K₂O≦

4 mol %;

0 mol %≦

Mgo≦

4 mol %; and

0 mol %≦

CaO≦

0.2 mol %, wherein the ratio ((mol % Al₂O₃+mol % B₂O₃);

mol % (Na₂O+K₂O+MgO+CaO)) is greater than 1; and

(e) SiO₂>

50 mol %;

11 mol %≦

Na₂O≦

25 mol %;

7 mol %≦

Al₂O₃≦

26 mol %;

0 mol %≦

B₂O₃≦

9 mol %;

0 mol %≦

K₂O≦

2.5 mol %;

0 mol %≦

MgO≦

8.5 mol %; and

0 mol %≦

CaO≦

1.52 mol %.

20. The antimicrobial, chemically strengthened glass according to claim 1, wherein the composition of the glass article is selected from the group consisting of alkali aluminosilicate glass and an alkali aluminoborosilicate glass, and further wherein the concentration of the plurality of Ag⁺¹ ions on the surface of the glass article is in the range of 0.01 μ

g/cm² and 0.035 μ

g/cm², and the surface of the glass article is non-cytotoxic.

21. The antimicrobial, chemically strengthened glass according to claim 1, wherein the glass article exhibits a light transmission, uncorrected for reflection losses, of at least 88% over the wavelength range of 400 nm to 750 nm.

22. The antimicrobial, chemically strengthened glass according to claim 1, wherein the glass article exhibits a light transmission at 428 nm and at 650 nm, such that the light transmission at 428 nm divided by the light transmission at 650 nm is at least 0.99.

23. An antimicrobial, chemically strengthened glass comprising:

a glass article;

a compressive stress layer extending to a first selected depth in the glass article; and

an antimicrobial Ag+ region extending from the surface of the glass article to a second selected depth in the glass article, the Ag+ region having a plurality of Ag⁺¹ ions,

wherein the compressive stress in the compressive stress layer is at least 250 MPa, and the concentration of the plurality of Ag⁺¹ ions on the surface of the glass article is in the range of greater than zero to less than or equal to 0.08 μ

g/cm².