COATED GLAZING

Abstract

A coated glazing includes a transparent glass substrate and a coating located on the glass substrate. The coating includes at least the following layers in sequence starting from the glass substrate: a first layer having a refractive index of more than 1.6, an optional second layer having a refractive index that is less than the refractive index of the first layer, a third layer based on tin dioxide doped with fluorine, and a fourth layer based on titanium oxide, wherein the fourth layer is photocatalytic.

Claims

1.-23. (canceled)

24. A coated glazing comprising: a transparent glass substrate, and a coating located on the glass substrate, wherein the coating comprises at least the following layers in sequence starting from the glass substrate: a first layer having a refractive index of more than 1.6, an optional second layer having a refractive index that is less than the refractive index of the first layer, a third layer based on tin dioxide doped with fluorine, and a fourth layer based on titanium oxide, wherein the fourth layer is photocatalytic.

25. The coated glazing according to claim 24, wherein the glazing further comprises an intervening layer based on an oxide of silicon and located between the third and fourth layers.

26. The coated glazing according to claim 25, wherein the intervening layer is based on silicon dioxide.

27. The coated glazing according to claim 24, wherein the glazing further comprises a lower layer having a refractive index that is less than the refractive index of the first layer and wherein the lower layer is located between the glass substrate and the first layer.

28. The coated glazing according to claim 27, wherein the lower layer is based on an oxide of a metalloid, preferably based on an oxide of silicon or silicon oxynitride.

29. The coated glazing according to claim 27, wherein the lower layer has a thickness of at least 5 nm, but at most 30 nm.

30. The coated glazing according to claim 25, wherein when the intervening layer is present, the first layer has a thickness of at least 5 nm, but at most 35 nm.

31. The coated glazing according to claim 25, wherein when the intervening layer is present, preferably the second layer has a thickness of at least 15 nm, but at most 50 nm.

32. The coated glazing according to claim 25, wherein when the intervening layer is present, the third layer has a thickness of at least 100 nm, but at most 300 nm.

33. The coated glazing according to claim 25, wherein the intervening layer has a thickness of at least 5 nm, but at most 40 nm.

34. The coated glazing according to claim 25, wherein when the intervening layer is present, the fourth layer has a thickness of at least 5 nm, but at most nm.

35. The coated glazing according to claim 24, wherein the first layer is based on an oxide of a metal, preferably the first layer is based on tin dioxide, niobium oxide, titanium dioxide, SiCO or tantalum oxide.

36. The coated glazing according to claim 24, wherein the first layer is based on tin dioxide.

37. The coated glazing according to claim 24, wherein the second layer is present and based on an oxide of a metalloid, preferably the second layer is based on a silicon oxide or silicon oxynitride.

38. The coated glazing according to claim 25, wherein the coated glazing comprises: a transparent glass substrate, and a coating located on the glass substrate, wherein the coating comprises at least the following layers in sequence starting from the glass substrate: a first layer having a refractive index of more than 1.6, wherein the first layer is based on tin dioxide, wherein the first layer has a thickness of at least 5 nm, but at most nm; a second layer having a refractive index that is less than the refractive index of the first layer, wherein the second layer is based on silicon dioxide, wherein the second layer has a thickness of at least 15 nm, but at most 50 nm; a third layer based on tin dioxide doped with fluorine, wherein the third layer has a thickness of at least 100 nm, but at most 300 nm; an intervening layer based on silicon dioxide, wherein the intervening layer has a thickness of at least 5 nm, but at most 40 nm; and a fourth layer based on titanium dioxide, wherein the fourth layer is photocatalytic and wherein the fourth layer has a thickness of at least 5 nm, but at most 35 nm.

39. The coated glazing according to claim 25, wherein the coated glazing comprises: a transparent glass substrate, and a coating located on the glass substrate, wherein the coating comprises at least the following layers in sequence starting from the glass substrate: a lower layer based on an oxide of silicon, a first layer having a refractive index of more than 1.6, wherein the first layer is based on tin dioxide, a second layer having a refractive index that is less than the refractive index of the first layer, wherein the second layer is based on an oxide of silicon, a third layer based on tin dioxide doped with fluorine, an intervening layer based on an oxide of silicon, and a fourth layer based on titanium dioxide, wherein the fourth layer is photocatalytic.

40. The coated glazing according to claim 25, wherein the coated glazing comprises: a transparent glass substrate, and a coating located on the glass substrate, wherein the coating comprises at least the following layers in sequence starting from the glass substrate: a lower layer based on silicon dioxide, wherein the lower layer has a thickness of at least 5 nm, but at most 30 nm; a first layer having a refractive index of more than 1.6, wherein the first layer is based on tin dioxide, wherein the first layer has a thickness of at least 5 nm, but at most nm; a second layer having a refractive index that is less than the refractive index of the first layer, wherein the second layer is based on silicon dioxide, wherein the second layer has a thickness of at least 15 nm, but at most 50 nm; a third layer based on tin dioxide doped with fluorine, wherein the third layer has a thickness of at least 100 nm, but at most 300 nm; an intervening layer based on silicon dioxide, wherein the intervening layer has a thickness of at least 5 nm, but at most 40 nm; and a fourth layer based on titanium dioxide, wherein the fourth layer is photocatalytic and wherein the fourth layer has a thickness of at least 5 nm, but at most 35 nm.

41. The coated glazing according to claim 24, wherein the coating has a static water contact angle of at most 40°, more preferably at most 30°, even more preferably at most 25°, most preferably at most 20° after irradiation of the glazing using a UV lamp of peak wavelength 351 nm at an intensity of 0.73 W/m2 at 45° C. for 30 min.

42. The coated glazing according to claim 24, wherein the coated glazing reduces the survival of one or more microbes on the coated surface of the substrate, such as for example bacteria and/or viruses, compared to an uncoated substrate that is otherwise the same as the coated substrate.

43. A method of providing a coating glazing with anticondensation, self-cleaning and/or antimicrobial properties, comprising irradiating the coated glazing according to claim 24 with UV light from an artificial UV light source and/or from daylight for at least 1 min, preferably wherein the UV light has a peak wavelength above 200 nm, more preferably above 220 nm, even more preferably above 250 nm.

Description

[0132] The invention will now be further described by way of the following specific embodiments, which are given by way of illustration and not of limitation, with reference to the accompanying drawing in which:

[0133] FIG. 1 is a schematic view, in cross-section, of a coated glazing with a four-layer coating in accordance with certain embodiments of the present invention,

[0134] FIG. 2 is a schematic view, in cross-section, of a coated glazing with a five-layer coating in accordance with certain embodiments of the present invention, and

[0135] FIG. 3 is a schematic view, in cross-section, of a coated glazing with a six-layer coating in accordance with certain embodiments of the present invention.

[0136] FIG. 1 shows a cross-section of a coated glazing 1 according to certain embodiments of the present invention. Coated glazing 1 comprises a transparent float glass substrate 2 that has been sequentially coated using CVD with a first layer based on tin dioxide 3, a second layer based on silicon dioxide 4, a third layer based on fluorine doped tin oxide 5 and a fourth layer based on titanium dioxide 6. The CVD may be carried out in conjunction with the manufacture of the glass substrate in the float glass process.

[0137] FIG. 2 similarly shows a coated glazing 7 identical to the coated glazing 1 depicted in FIG. 1 except that an intervening layer based on silicon dioxide 8 is located between the third layer based on fluorine doped tin oxide 5 and the fourth layer based on titanium dioxide 6.

[0138] FIG. 3 shows a coated glazing 9 identical to the coated glazing 7 depicted in FIG. 2 except that a lower layer based on silicon dioxide 10 is located between the transparent float glass substrate 2 and the first layer based on tin dioxide 3.

EXAMPLES

[0139] Examples 1-6 according to the invention were prepared using atmospheric pressure CVD as part of the float glass process. The transparent glass substrate used for each Example was clear soda-lime-silica glass with a thickness of 4 mm. Comparative Example 7 was commercially available Pilkington Anti-Condensation Glass, of 4 mm thickness. Comparative Example 8 was commercially available Pilkington Activ™, of 4 mm thickness.

[0140] The SnO.sub.2 layers were deposited over the glass surface using the following components: [0141] N.sub.2 carrier gas, O.sub.2, dimethyltin dichloride, and H.sub.2O.

[0142] The SiO.sub.2 layers were deposited over the glass surface using the following components: [0143] N.sub.2 carrier gas, He carrier gas, O.sub.2, C.sub.2H.sub.4, and SiH.sub.4.

[0144] The SnO.sub.2:Sb layers were deposited over the glass surface using the following components:

[0145] N.sub.2 and He carrier gas, O.sub.2, dimethyltin dichloride, 30-50 wt % triphenyl antimony in ethyl acetate, and H.sub.2O.

[0146] The TiO.sub.2 layers were deposited over the glass surface using the following components: [0147] Titanium tetrachloride in ethyl acetate (ratio EtOAc:TiCl.sub.4 1.8-2.2) for Comparative Example 8. [0148] Titanium tetraisopropoxide and O.sub.2 for Examples 1-6.

[0149] The SnO.sub.2:F layers were deposited over the glass surface using the following components: [0150] N.sub.2 carrier gas, O.sub.2, dimethyltin dichloride, HF, and H.sub.2O.

[0151] The thicknesses of the individual layers of the samples were as follows:

[0152] Examples 1-6: Glass/SiO.sub.2 (20 nm)/SnO.sub.2 (25 nm)/SiO.sub.2 (25 nm)/SnO.sub.2:F (230 nm)/TiO.sub.2 (Examples 1-2, ≥1 nm, <5 nm; Examples 3-4, 5 nm, <10 nm; Example 5, 15 nm, Example 6, 18 nm)

[0153] Comparative Example 7: Glass/SiO.sub.2 (20 nm)/SnO.sub.2 (25 nm)/SiO.sub.2 (25 nm)/SnO.sub.2:F (230 nm)

[0154] Comparative Example 8: SiO.sub.2 (35 nm)/TiO.sub.2 (17 nm).

[0155] The optical properties shown below in Table 1 were determined using a HunterLab™ Ultrascan Pro spectrophotometer. The layer thicknesses of the Examples were determined by scanning electron microscopy (SEM) using an FEI Nova NanoSEM™ 450 and EDAX Octane plus EDS detector with TEAM software.

TABLE-US-00001 TABLE 1 Optical properties of Examples 1-6 according to the invention and Comparative Example 7 Coated Reflection (%) Glass Reflection (%) Transmission (%) Sample a* b* Y a* b* Y a* b* Y Example 1 −1.81 4.62 14.7 −2.08 4.8 14.22 −0.32 −0.75 81.7 Example 2 0.26 4.59 14.75 −0.03 4.84 14.4 −0.99 −0.75 81.7 Example 3 −0.03 4.37 15.17 −0.36 4.91 14.75 −0.97 −0.72 81.36 Example 4 −1.36 4.91 15.24 −1.45 5.39 14.96 −0.48 −0.79 80.92 Example 5 0.875 3.54 15.72 0.38 4.35 15.19 −1.21 −0.35 80.45 Example 6 0.445 3.88 15.90 0.03 4.54 15.6 −1.28 −0.28 80.14 Comparative −2.25 −0.6 13.64 −2.35 −0.22 13.3 −0.23 0.66 82.79 Example 7

[0156] The static water contact angle of these samples was determined by measuring the diameter of a water droplet (5 μl) on the glass surface after irradiation of the glazing using a UV lamp (peak wavelength 351 nm) at an intensity of 0.73 W/m2 at 45° C. for 30 min (shown in the column labelled “UV” in Table 2 below). The static water contact angle of these samples was also determined immediately after storing the samples in the dark for 72 hrs (shown in the column labelled “Dark” in Table 2 below).

TABLE-US-00002 TABLE 2 Comparison of static water contact angles for Examples 1-6 according to the invention and Comparative Examples 7 and 8 in the dark and after UV irradiation Static Water Contact Angle Comparison Sample Dark UV Example 1 80° 17° Example 2 83° 16° Example 3 73° 22° Example 4 78° 24° Example 5 77° 15° Example 6 74° 16° Comparative Example 7 61° 60° Comparative Example 8 79° 10°

[0157] The static water contact angle may be attributed to the photoactivity of the coated surface, which is capable of destroying organic dirt on the surface which would otherwise increase the contact angle of the surface above 30° and act as a potential nucleation area for external condensation. The above results demonstrate that the coated glazings according to the present invention exhibit very low static water contact angles upon irradiation with UV light.

[0158] The invention is not restricted to the details of the foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.