Glazing for minimizing bird collisions

Abstract

A glazing for minimising bird collisions with glazings has at least one substrate including a first major surface. The first major surface includes one or more first regions and one or more second regions, and the one or more first regions are coated with a UV reflective coating of a thickness of at least 5 nm. The one or more second regions are at least partially coated with the UV reflective coating at a thickness of less than 5 nm, or the UV reflective coating is completely absent in the one or more second regions. The UV reflective coating is coated with a protective coating, with the protective coating being based on an oxide or nitride of a metalloid or an oxide or nitride of a metal.

Claims

1. A glazing for minimising bird collisions with glazings, wherein the glazing comprises at least one substrate comprising a first major surface, wherein the first major surface comprises one or more first regions and one or more second regions, wherein the one or more first regions are coated with a UV reflective coating and the UV reflective coating of the one or more first regions has a thickness of at least 5 nm, wherein the one or more second regions are at least partially coated with the UV reflective coating and the UV reflective coating of the one or more second regions has a thickness of less than 5 nm or wherein the UV reflective coating is completely absent in the one or more second regions, wherein the UV reflective coating is coated with a protective coating, wherein any regions of the first major surface where the UV reflective coating is absent are coated with the protective coating, wherein the protective coating is based on an oxide or nitride of a metalloid or an oxide or nitride of a metal, and wherein the protective coating has a thickness of at least 0.5 nm but at most 15 nm.

2. The glazing according to claim 1, wherein the protective coating is not overcoated.

3. The glazing according to claim 1, wherein the protective coating directly contacts the UV reflective coating.

4. The glazing according to claim 1, wherein the UV reflective coating directly contacts the first major surface of the substrate.

5. The glazing according to claim 1, wherein an antireflection layer is located between the UV reflective coating and the first major surface of the substrate.

6. The glazing according to claim 1, wherein the one or more second regions are at least partially coated with the UV reflective coating and the UV reflective coating has a thickness of less than 4.7 nm.

7. The glazing according to claim 1, wherein the protective coating is based on a material that is different to the material that the UV reflective coating is based on.

8. The glazing according to claim 1, wherein the protective coating is based on silicon dioxide, zirconium oxide, silicon nitride and/or nickel chromium oxide.

9. The glazing according to claim 1, wherein the protective coating is based on silicon dioxide and/or silicon nitride.

10. The glazing according to claim 1, wherein the protective coating has a thickness of at least 1 nm, but at most 10 nm.

11. The glazing according to claim 1, wherein the UV reflective coating is based on an oxide and/or nitride of one or more of titanium, vanadium, chromium, zirconium, niobium, tantalum, hafnium and tungsten.

12. The glazing according to claim 1, wherein the UV reflective coating defines a patterned arrangement on the first major surface.

13. The glazing according to claim 12, wherein the patterned arrangement comprises a plurality of stripes.

14. The glazing according to claim 13, wherein at least one of the stripes has a thickness that changes by 10 nm or less over every 1 mm in width.

15. The glazing according to claim 1, wherein the UV reflective coating of the one or more first regions has a thickness of at least 10 nm, but at most 100 nm.

16. The glazing according to claim 1, wherein the at least one substrate is a glass substrate or a polymeric substrate.

17. The glazing according to claim 1, wherein the UV reflective coating and/or the protective coating have been deposited via sputtering.

18. The glazing according to claim 1, wherein the glazing comprises at least one glass substrate comprising a first major surface, wherein the first major surface comprises one or more first regions and one or more second regions, wherein the one or more first regions are coated with a UV reflective coating and the UV reflective coating has a thickness of at least 10 nm but at most 50 nm, wherein the one or more second regions are at least partially coated with the UV reflective coating and the UV reflective coating has a thickness of less than 4.7 nm, or wherein the UV reflective coating is completely absent in the one or more second regions, wherein the UV reflective coating is coated with a protective coating, wherein the protective coating directly contacts the UV reflective coating, wherein, if present, any regions of the first major surface where the UV reflective coating is absent are coated with the protective coating and the protective coating directly contacts the regions of the first major surface where the UV reflective coating is absent, wherein the protective coating is based on an oxide of silicon, and wherein the UV reflective coating is based on titanium dioxide.

19. A glazing for minimising bird collisions with glazings, wherein the glazing comprises at least one substrate comprising a first major surface, wherein the first major surface comprises one or more first regions and one or more second regions, wherein the one or more first regions are coated with a UV reflective coating and the UV reflective coating of the one or more first regions has a thickness of at least 5 nm, wherein the one or more second regions are at least partially coated with the UV reflective coating and the UV reflective coating of the one or more second regions has a thickness of less than 5 nm or wherein the UV reflective coating is completely absent in the one or more second regions, wherein the UV reflective coating is coated with a protective coating, wherein the protective coating directly contacts any regions of the first major surface where the UV reflective coating is absent, wherein the protective coating is based on an oxide or nitride of a metalloid or an oxide or nitride of a metal, and wherein the protective coating has a thickness of at least 0.5 nm but at most 15 nm.

20. A glazing for minimising bird collisions with glazings, wherein the glazing comprises at least one substrate comprising a first major surface, wherein the first major surface comprises one or more first regions and one or more second regions, wherein the one or more first regions are coated with a UV reflective coating and the UV reflective coating of the one or more first regions has a thickness of at least 5 nm, wherein the one or more second regions are at least partially coated with the UV reflective coating and the UV reflective coating of the one or more second regions has a thickness of less than 5 nm or wherein the UV reflective coating is completely absent in the one or more second regions, wherein the UV reflective coating is coated with a protective coating, wherein the protective layer is placed to overlap both at least one first region and at least one second region, wherein the protective coating is based on an oxide or nitride of a metalloid or an oxide or nitride of a metal, and wherein the protective coating has a thickness of at least 0.5 nm but at most 15 nm.

Description

(1) 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 drawings in which:

(2) FIG. 1 shows a schematic cross-sectional view of a glazing in accordance with the present invention; and

(3) FIG. 2 shows a graph of wavelength vs % reflectance for a TiO.sub.2 coated glazing with and without a protective coating of SiO.sub.2: 9 wt % Al based on the total silicon plus aluminium content.

(4) FIG. 1 shows a schematic cross-sectional view of a glazing 1 in accordance with the present invention. Glazing 1 comprises a clear float glass ply 2 (e.g. with a thickness of 4 mm, a length of 100 cm and a width of 65 cm) coated with soft-edged TiO.sub.2 stripes 3 with a bell-shaped thickness profile in which the thickness of the stripes 3 is 36 nm at the centre of each stripe 3 and tails off to zero at each edge. The soft-edged TiO.sub.2 stripes 3 are formed by sputtering through a slot shield in which the slots are e.g. 16 mm wide. Sputtering through the slot shield also results in the width of each stripe 3 being greater (e.g. a width of approximately 40 mm) than the 10 mm wide slots.

(5) Each stripe 3 extends parallel to and along the entire length of the glass ply 2. Adjacent stripes 3 are parallel and spaced apart across the entire width of the glass ply 2 such that there is 100 mm from the centre of one stripe 3 to the centre of an adjacent stripe 3.

(6) The TiO.sub.2 stripes 3 and the surface of glass ply 2 in the gaps between the stripes 3 are coated with a 2 nm thick protective coating of SiO.sub.2:Al (7-10 wt % Al based on the total silicon plus aluminium content).

(7) FIG. 2 shows a graph of wavelength vs % reflectance for the glazing 1 shown in FIG. 1 and described above in comparison with the same glazing but with the protective coating of SiO.sub.2: 9 wt % Al (based on the total silicon plus aluminium content) omitted. The graph shows that the presence of the protective coating on the TiO.sub.2 stripes (see Stripe 2 nm SiO2+TiO2 plot) results in only a tiny difference to the appearance in reflection of the stripes in comparison with the uncoated stripes (see Stripe TiO2 plot). Likewise, the presence of the protective coating on the surface of the glass in the gaps between the stripes (see Gap 2 nm SiO2+TiO2 plot) affords an almost identical appearance in reflection of the gaps in comparison with the uncoated gaps (see Gap TiO2 plot).

EXAMPLES

(8) Several examples were prepared in accordance with the glazing of FIG. 1 but varying the material of the protective coating. For each example a clear float glass ply of thickness 6 mm, length 3210 mm and width 2250 mm was coated with an 36 nm thick UV reflective coating of TiO.sub.2 using magnetron sputtering through a slot shield as mentioned above in relation to FIG. 1 and as described in WO 2016/198901.

(9) Without further coating, one of these examples served as Comparative Example 1. Examples according to the invention were prepared by further coating the examples as described below:

(10) A variety of experimental protective layers were deposited over the pre-prepared striped TiO.sub.2 samples. Deposition was carried out using a Von Ardenne LS780S laboratory sputtering system using the conditions set out below in Table 1. The plant was equipped with targets of the study materials (or the metals they are derived from), mounted on 150 mm diameter circular planar magnetron sources. For reactively sputtered materials, voltage hysteresis curves were performed to obtain initial sputtering conditions and stoichiometric information. Rate runs were carried out for all materials to obtain deposition rates and check for transparency.

(11) TABLE-US-00001 TABLE 1 Process conditions for deposition of the protective coating Nominal Speed Power Deposited thickness Target (mm/ Supply Power Ar O.sub.2 N.sub.2 Material (nm) Material min) Passes Mode (kW) (sccm) (sccm) (sccm) SiO.sub.2:Al 1 Si- 2.5 1 Pulsed 0.5 30 9 10 wt % DC Al SiO.sub.2:Al 2 Si- 2.3 1 Pulsed 1 30 19 10 wt % DC Al SiO.sub.2:Al 5 Si- 1 1 Pulsed 1 30 19 10 wt % DC Al SiO.sub.2:Al 10 Si- 1 2 Pulsed 1 30 19 10 wt % DC Al ZrO.sub.2 2 Zr 1 1 DC 0.8 30 13 ZrO.sub.2 5 Zr 1 5 DC 0.8 30 13 ZrO.sub.2 10 Zr 1.07 6 DC 0.8 30 13 Si.sub.3N.sub.4:Al 2 Si- 2.5 1 Pulsed 0.3 30 10 10 wt % DC Al Si.sub.3N.sub.4:Al 5 Si- 2.5 1 Pulsed 1 30 17 10 wt % DC Al Si.sub.3N.sub.4:Al 10 Si- 1.1 1 Pulsed 1 30 17 10 wt % DC Al NiCr.sub.xO.sub.y 2 Ni- 2 1 DC 1 30 21 20 wt % Cr NiCr.sub.xO.sub.y 5 Ni- 1.2 1 DC 1 30 21 20 wt % Cr NiCr.sub.xO.sub.y 10 Ni- 1.21 2 DC 1 30 21 20 wt % Cr TiO.sub.2 2 Ti 0.85 2 Pulsed 1 30 10 DC TiO.sub.2 5 Ti 1.35 8 Pulsed 1 30 10 DC TiO.sub.2 10 Ti 1.35 16 Pulsed 1 30 10 DC

(12) Accordingly, Examples with protective coatings of SiO.sub.2:Al, ZrO.sub.2, Si.sub.3N.sub.4:Al, NiCr.sub.xO.sub.y and TiO.sub.2 of varying thicknesses as shown in Table 2 below were obtained. These Examples and Comparative Example 1 were tested for their mechanical durability in an oil rub test.

(13) An oil rub test serves to simulate the influence of cutting oils used for cutting glass substrates on the mechanical robustness of a coating. Coated glass substrates that do not withstand an oil rub test are difficult to process and are unsuitable for most practical applications. The examples were rubbed using a felt pad with an area 1.21.2 cm soaked in microscope oil of refractive index 1.52 (1.515 to 1.517). The examples were subjected to 500 cycles with a 1,000 g load at a speed of 37 cycles per minute. The oil rubbed samples were then evaluated, where any visible removal of coating was deemed a fail.

(14) TABLE-US-00002 TABLE 2 As deposited oil rub test performance of a comparative example and several examples according to the invention As deposited oil rub test performance Protective coating Thickness of protective coating material None ~1 nm ~2 nm ~5 nm ~10 nm Comparative Example Fail 1: None Example 1: SiO.sub.2:9 wt % Pass Pass Pass Pass Al.sub.2O.sub.3 Example 2: ZrO.sub.2 Pass Fail Pass Example 3: Si.sub.3N.sub.4:Al Pass Pass Pass Example 4: NiCr.sub.xO.sub.y Fail Pass Pass Example 5: TiO.sub.2 Fail Fail Fail

(15) The Examples in Table 2 that passed the oil rub test were remade, subjected to a toughening simulation (by heating in a furnace to 650 C. for a 5.5 minute hold for 6 mm thick glass) and then exposed to the oil rub test. All of these Examples passed, showing that they retain their durability after toughening.

(16) Table 2 illustrates that protective coatings of either SiO.sub.2:Al or Si.sub.3N.sub.4:Al provide excellent durability performance in the oil rub test. ZrO.sub.2 and NiCr.sub.xO.sub.y both afford the necessary durability depending on the thickness of the protective coating.

(17) Protective coatings such as SiO.sub.2:Al and ZrO.sub.2 perform well at thicknesses of 2 nm or less which makes them useful in terms of having minimal disruption on the desired optical thickness of the UV reflective coating. However, protective coatings of Si.sub.3N.sub.4:Al, ZrO.sub.2 or NiCr.sub.xO.sub.y could all affect the ability of the glazing to minimise bird collisions since they reduce the contrast ratio between the UV reflective coating stripe and the uncoated glass, by reducing the reflectance of the stripe and increasing the reflectance of the otherwise uncoated area. Thin SiO.sub.2:Al does not exhibit this disadvantage because, as shown in FIG. 2 and discussed above, it barely alters the reflectance of the coated or uncoated regions.

(18) 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.