CORROSION-RESISTANT AND/OR CLEANABLE COATED GLASS SUBSTRATE

Abstract

A corrosion-resistant and/or cleanable coated glass substrates includes an outermost layer comprising from 0.5 to 20 atomic % cerium based on all components and to processes for producing corrosion-resistant and/or cleanable coated glass substrates including a step of sputtering a sputtering target comprising cerium to provide a layer comprising cerium oxide directly or indirectly on a first surface. The invention also provides the use of a layer comprising cerium oxide as a corrosion-resistant and/or cleanable coating on glass substrates, and to bath screens, shower screens and/or splash screens comprising corrosion-resistant and/or cleanable coated glass substrates.

Claims

1.-24. (canceled)

25. A corrosion-resistant and/or cleanable coated glass substrate comprising: a glass substrate with a first surface; and a layer comprising cerium oxide directly or indirectly on the first surface, wherein: the layer comprising cerium oxide is the outermost layer on the first surface; and the layer comprising cerium oxide comprises from 0.5 to 20 atomic % cerium based on all components.

26. The coated glass substrate according to claim 25, wherein the coated glass substrate exhibits a haze increase of 1% or below after 2 hours immersed in 1M NaOH or 1M HCl at 23 C.

27. The coated glass substrate according to claim 25, wherein the layer comprising cerium oxide has a thickness of from 1 nm to 500 nm, preferably from 5 nm to 250 nm, more preferably from 10 nm to 100 nm.

28. The coated glass substrate according to claim 25, wherein the layer comprising cerium oxide has a refractive index in the range 2.28 to 2.44.

29. The coated glass substrate according to claim 25, wherein the layer comprising cerium oxide is the only layer on the first surface.

30. The coated glass substrate according to claim 25, further comprising an underlayer between the layer comprising cerium oxide and the first surface.

31. The coated glass substrate according to claim 30, wherein the underlayer comprises silicon oxide, preferably the underlayer comprising silicon oxide is directly on the first surface, more preferably the underlayer comprising silicon oxide is directly on the first surface and the layer comprising cerium oxide is directly on the underlayer.

32. The coated glass substrate according to claim 25, wherein the layer comprising cerium oxide comprises from 1 to 10 atomic % cerium based on all components, preferably from 2 to 8 atomic % cerium based on all components.

33. The coated glass substrate according to claim 25, wherein the layer comprising cerium oxide is substoichiometric in oxygen.

34. The coated glass substrate according to claim 25, wherein the layer comprising cerium oxide further comprises titanium, preferably the layer comprising cerium oxide comprises from 50 to 95 atomic % titanium based on titanium and cerium, more preferably the layer comprising cerium oxide comprises from 70 to 90 atomic % titanium based on titanium and cerium, even more preferably the layer comprising cerium oxide comprising from 75 to 85 atomic % titanium based on titanium and cerium.

35. The coated glass substrate according to claim 25, wherein the layer comprising cerium oxide comprises less than 10 atomic % silicon based on all components, preferably the layer comprising cerium comprises less than 1 atomic % silicon based on all components, more preferably the layer comprising cerium is essentially free of silicon.

36. The coated glass substrate according to claim 25, wherein the layer comprising cerium oxide comprises less than 10 atomic % aluminium based on all components, preferably the layer comprising cerium comprises less than 1 atomic % aluminium based on all components, more preferably the layer comprising cerium is essentially free of aluminium.

37. The coated glass substrate according to claim 25, wherein the coated glass substrate exhibits a water contact angle of greater than 30, preferably greater than 50, even more preferably greater than 60.

38. The coated glass substrate according to claim 25, wherein the substrate is toughened glass.

39. A process for producing a corrosion-resistant and/or cleanable coated glass substrate, the process comprising: providing a glass substrate with a first surface; providing a sputtering target comprising cerium; and sputtering the sputtering target comprising cerium to provide a layer comprising cerium oxide directly or indirectly on the first surface.

40. The process according to claim 39, wherein the sputtering target comprises titanium, preferably from 50 to 95 atomic % titanium based on titanium and cerium, more preferably the sputtering target comprises from 70 to 90 atomic % titanium based on titanium and cerium, even more preferably the sputtering target comprises from 75 to 85 atomic % titanium based on titanium and cerium.

41. The process according to claim 39, wherein the step of sputtering the sputtering target is carried out in an atmosphere comprising a noble gas, preferably the noble gas is argon or krypton.

42. The process according to claim 39, further comprising cleaning the surface before the step of sputtering the sputtering target, preferably cleaning the surface comprises one or more of: abrasion with ceria; washing with alkaline aqueous solution; deionised water rinse; and plasma treatment.

43. The process according to claim 39, wherein the sputtering target is a cylindrical sputtering target.

44. The process according to claim 39, further comprising the step of heat treating the soda lime silica glass substrate after the step of sputtering the sputtering target, preferably wherein the step of heat treating the soda lime silica glass substrate comprises heating the soda lime silica glass substrate to at least 600 C. for at least 5 minutes.

45. The process according to claim 39, further comprising the step of applying an underlayer to the first surface prior to the step of sputtering the sputtering target, preferably the step of applying the underlayer comprises depositing a layer comprising silica by chemical vapour deposition, physical vapour deposition, or liquid deposition, preferably by chemical vapour deposition.

46. A bath screen, a shower screen and/or splash screen comprising a corrosion-resistant and/or cleanable coated glass substrate as claimed in claim 25.

47. A bath screen, shower screen and/or splash screen as claimed in claim 46, further comprising fixings to fix the bath screen and/or a shower screen in position for use, preferably the fixings comprise adhesive portions or mechanical attachment portions to attach the fixings to the splash screen.

Description

[0068] The present invention will now be described by way of example only, and with reference to, the accompanying drawings, in which:

[0069] FIG. 1 illustrates schematically a coated substrate according to an embodiment of the present invention;

[0070] FIG. 2 illustrates schematically a coated substrate according to an embodiment of the present invention, comprising an underlayer.

[0071] FIG. 1 illustrates schematically a coated glass substrate 1 comprising: a substrate of soda lime silica glass 2 with a first surface 21; and a layer 3 comprising cerium oxide directly on the first surface 21, wherein the layer 3 comprising cerium oxide is the outermost layer on the first surface 21.

[0072] FIG. 2 illustrates schematically a coated glass substrate 1 comprising: a substrate of soda lime silica glass 2 with a first surface 21; and a layer 3 comprising cerium oxide indirectly on the first surface 21, wherein the layer 3 comprising cerium oxide is the outermost layer on the first surface 21, further comprising an underlayer 4 between the layer comprising cerium oxide 3 and the first surface 21 and wherein the underlayer 4 is directly on the first surface 21. Preferably the underlayer 4 comprises silicon oxide.

[0073] The invention is further illustrated, but not limited, by the following examples.

[0074] Examples according to the invention were prepared by sputtering a rotatable ceramic target comprising 65 weight % TiO.sub.2 and 35 weight % CeO.sub.2 (corresponding to 80.0 atomic % titanium and 20.0 atomic % cerium based on cerium and titanium, and corresponding to 26.7 atomic % titanium, 6.7 atomic % cerium and 66.7 atomic % oxygen based on all components) with length 23 inches and diameter 5.914 inches. A layer comprising cerium, titanium and oxygen CeTiO.sub.x was formed.

[0075] Examples 1 to 3 were prepared by sputtering the layer comprising CeTiO.sub.x directly onto a soda-lime silica glass substrate, while examples 4 to 6 were prepared by sputtering the layer comprising CeTiO.sub.x onto an underlayer comprising silicon oxide. The underlayer comprising silicon oxide was produced in these examples using chemical vapour deposition with a thickness of 20 to 30 nm.

[0076] Where examples and comparative examples were submitted to heat treatment, this constituted a temperature of 650 C. for 5 minutes.

CHARACTERISATION OF EXAMPLES

[0077] The coated substrates were tested for optical properties (according to ISO 9050) water contact angle (50 l deionized water droplet) and resistance to humidity-induced corrosion.

[0078] Table 1 depicts the average water contact angle (n=5) of 1010 cm samples measured after deposition (AD), following heat treatment and 2 weeks aging in atmosphere (HT 2 weeks) and following heat treatment and 3 weeks aging in atmosphere (HT 3 weeks). Water contact angle was measured with deionised water using a FTA200 with FTA32 software, both available from First Ten Angstroms, Newark, CA, USA.

TABLE-US-00001 TABLE 1 Average Water Contact Angle Sample Coating AD HT 2 weeks HT 3 weeks 1 CeTiO.sub.x (10 nm) 60.79 47.76 50.68 2 CeTiO.sub.x (25 nm) 60.34 18.23 25.78 3 CeTiO.sub.x (50 nm) 62.06 22.66 37.10 4 SiO.sub.2, CeTiO.sub.x (10 nm) 59.47 24.62 35.56 5 SiO.sub.2, CeTiO.sub.x (25 nm) 61.82 39.27 46.94 6 SiO.sub.2, CeTiO.sub.x (50 nm) 64.32 45.86 50.39

[0079] From Table 1 it can be seen that substrates with surprisingly high water contact angles of greater than 60 may be obtained with a CeTiO.sub.x, compared to untreated glass which has a water contact angle of 25. A high water contact angle is associated with improved cleanability. As such, a cleanable substrate is produced by the application of the inventive coating.

[0080] Indeed, high water contact angles may be obtained with a coating of only 10 nm thickness, and that this is surprisingly long lasting. Meanwhile, a coating with a surprisingly high water contact angle may be obtained with a CeTiO.sub.x coating of 50 nm, and the aging performance of such a coating is markedly improved by the presence of a silicon oxide underlayer. Similarly, the aging performance of a CeTiO.sub.x coating of 25 nm is improved by the presence of a silicon oxide underlayer.

[0081] As such, in embodiments where a silicon oxide underlayer is desired, it is desirable that the thickness of a CeTiO.sub.x layer is greater than 10 nm, preferably 25 nm or greater, more preferably 50 nm or greater, such as from greater than 10 nm to 500 nm, preferably 25 nm to 250 nm, more preferably from 50 nm to 100 nm. It was noticed that water contact angle increases with aging to a stable value.

[0082] Examples and comparative examples were submitted to alkali corrosion testing, wherein heat treated samples were immersed in 1M NaOH at 23 C. for 2 hours. The change in haze was assessed (BYK Gardner Haze-gard plus) according to ASTM D1003 as depicted in Table 2, and the change in transmittance was assessed as depicted in Table 3.

TABLE-US-00002 TABLE 2 Haze, 2 Hours in 1M NaOH at 23 C. Sample Coating Initial 2 Hours Delta 1 CeTiO.sub.x (10 nm) 0.1 0.09 0.01 2 CeTiO.sub.x (25 nm) 0.15 0.14 0.01 3 CeTiO.sub.x (50 nm) 0.26 0.24 0.02 4 SiO.sub.2, CeTiO.sub.x (10 nm) 0.17 0.12 0.05 5 SiO.sub.2, CeTiO.sub.x (25 nm) 0.21 0.18 0.03 6 SiO.sub.2, CeTiO.sub.x (50 nm) 0.34 0.26 0.08

TABLE-US-00003 TABLE 3 Transmittance, 2 Hours in 1M NaOH at 23 C. Sample Coating Initial 2 Hours Delta 1 CeTiO.sub.x (10 nm) 89.5 89.5 0 2 CeTiO.sub.x (25 nm) 79.8 80 0.2 3 CeTiO.sub.x (50 nm) 68.1 68.1 0 4 SiO.sub.2, CeTiO.sub.x (10 nm) 91.1 91.1 0 5 SiO.sub.2, CeTiO.sub.x (25 nm) 80.9 81.2 0.3 6 SiO.sub.2, CeTiO.sub.x (50 nm) 67.1 67.1 0

[0083] Table 2 shows that all measured samples exhibited extremely low haze both initially and after alkali corrosion testing, indicating excellent corrosion resistance by CeTiO.sub.x coatings. Similarly, Table 3 shows that transmittance is reduced by increasing thickness of CeTiO.sub.x coating, but is increased, or only slightly reduced, by the presence of a silicon oxide underlayer. The change in transmittance caused by alkali corrosion testing is negligible.

[0084] Examples and comparative examples were submitted to acid corrosion testing, wherein heat treated samples were immersed in 1M HCl at 23 C. for 2 hours. The change in haze was assessed (BYK Gardner Haze-gard plus) according to ASTM D1003 as depicted in Table 2, and the change in transmittance was assessed as depicted in Table 3.

TABLE-US-00004 TABLE 4 Haze, 2 Hours in 1M HCl at 23 C. Sample Coating Initial 2 Hours Delta 1 CeTiO.sub.x (10 nm) 0.1 0.11 0.01 2 CeTiO.sub.x (25 nm) 0.14 0.12 0.02 3 CeTiO.sub.x (50 nm) 0.26 0.24 0.02 4 SiO.sub.2, CeTiO.sub.x (10 nm) 0.15 0.12 0.03 5 SiO.sub.2, CeTiO.sub.x (25 nm) 0.17 0.18 0.01 6 SiO.sub.2, CeTiO.sub.x (50 nm) 0.23 0.21 0.02

[0085] Table 4 shows that all measured samples exhibited extremely low haze both initially and after acid corrosion testing, indicating excellent corrosion resistance by CeTiO.sub.x coatings.

TABLE-US-00005 TABLE 5 Transmittance, 2 Hours in 1M HCl at 23 C. Sample Coating Initial 2 Hours Delta 1 CeTiO.sub.x (10 nm) 89.5 89.7 0.2 2 CeTiO.sub.x (25 nm) 80.1 80.4 0.3 3 CeTiO.sub.x (50 nm) 68 68.2 0.2 4 SiO.sub.2, CeTiO.sub.x (10 nm) 91.1 91.3 0.2 5 SiO.sub.2, CeTiO.sub.x (25 nm) 80.9 81.3 0.4 6 SiO.sub.2, CeTiO.sub.x (50 nm) 67.2 67.3 0.1

[0086] Table 5 shows that the change in transmittance caused by acid corrosion testing is negligible.

[0087] As such, CeTiO.sub.x coatings may be used to produce heat treated coated glass substrates with excellent cleanability and excellent corrosion resistance. Furthermore, the coated glass substrate responds very well to heat treatment, as such there is provided a heat treatable coated glass substrate which may be heat treated to produce a heat treated coated glass substrate with excellent cleanability and excellent corrosion resistance.