Glass with a coating to reduce bird collisions

Abstract

The invention relates to glass for reducing or preventing bird collisions, comprising a glass substrate (10) and a UV reflective coating provided on the glass substrate (10). The glass is fully coated with the UV reflective coating; the UV reflective coating reflects at least 70% in the 320-360 nm range and comprises multiple layers of titanium oxide and silicon oxide in sequence.

Description

[0001] GLASS WITH A COATING TO REDUCE BIRD COLLISIONS

[0002] TECHNICAL FIELD

[0003] The present invention relates to glass with a coating that is highly reflective to ultraviolet (UV) rays, designed to prevent or reduce bird collisions, and which also provides indoor UV protection due to its UV reflection properties.

[0004] BACKGROUND OF THE ART

[0005] Bird collisions with windows used in buildings are a significant problem. For example, certain buildings in Chicago (e.g., skyscrapers) are located on migratory bird routes. Birds flying along these routes repeatedly collide with these buildings because they cannot see the windows, resulting in the deaths of thousands of birds, particularly during migration seasons. Similarly, buildings located in environments such as forests or parks cause similar problems for birds living in those areas.

[0006] Traditional methods to reduce bird collisions with windows include the use of nets, stickers, or frit. However, these solutions are considered ineffective due to their aesthetic impact on architecture and / or because they do not make the glass more visible to birds.

[0007] EP3148948A1 discloses a glass unit designed to prevent or reduce bird collisions. In some example arrangements, the window includes an insulated glass (IG) unit with spaced first and second substrates, where at least one of the substrates supports a UV-reflective coating to reflect UV radiation, making the window more visible to birds. By making the window more visible to birds, bird collisions, and consequently bird deaths, can be reduced.

[0008] SUMMARY OF THE INVENTION

[0009] The object of the invention is to prevent or reduce bird collisions by making the glass used as a fagade material in the architectural sector more visible to birds.

[0010] In order to achieve above objective, the invention relates to glass with a UV reflective coating provided on a glass substrate, to prevent or reduce bird collisions. The glass features a UV reflective coating that reflects at least 70% in the 320-360 nm range and includes multiple layers of titanium oxide and silicon oxide, or titanium oxide, silicon oxide, and silicon oxynitride in sequence. An optical filter is obtained by sequentially coating the glass substrate with high and low refractive index dielectrics and determining the film thicknesses according to the wavelength of the light to be reflected during the coatings. As the number of layers increases, the number of interfaces between the high and low refractive index layers also increases, thereby enhancing the filter's selectivity. This allows the UV reflectivity to exceed 70% in the UV range (320 nm - 360 nm), while the transmittance in the visible range (380 nm-780 nm) exceeds 85%, thus preventing bird collisions or bird deaths with a coating structure that is detectable by birds but not by humans.

[0011] In a preferred embodiment of the invention, the first layer adjacent to the glass substrate contains titanium oxide. The use of titanium oxide ensures that the first layer of the glass has a high refractive index material.

[0012] In a preferred embodiment of the invention, the second layer adjacent to the first layer contains silicon oxide. The use of silicon oxide ensures that the second layer of the glass has a low refractive index material.

[0013] In a preferred embodiment of the invention, the third layer adjacent to the second layer contains titanium oxide. The use of titanium oxide ensures that the third layer of the glass has a high refractive index material.

[0014] In a preferred embodiment of the invention, the fourth layer adjacent to the third layer contains silicon oxide or a mixture of silicon oxide and silicon oxynitride. The use of silicon oxide or a silicon oxide and silicon oxynitride mixture ensures that the fourth layer of the glass has a low refractive index material.

[0015] In a preferred embodiment of the invention, the fifth layer adjacent to the fourth layer contains titanium oxide. The use of titanium oxide ensures that the fifth layer of the glass has a high refractive index material.

[0016] In a preferred embodiment of the invention, the sixth layer adjacent to the fifth layer contains silicon oxide or a mixture of silicon oxide and silicon oxynitride. The use of silicon oxide or a mixture of silicon oxide and silicon oxynitride ensures that the sixth layer of the glass has a low refractive index material. In a preferred embodiment of the invention, the seventh layer adjacent to the sixth layer contains titanium oxide. The use of titanium oxide ensures that the seventh layer of the glass has a high refractive index material.

[0017] In a preferred embodiment of the invention, the total thickness of the first, second, third, fourth, fifth, sixth, and seventh layers is in the range of 265-300 nm. This ensures that the desired level of reflection of the light targeted for reflection is achieved.

[0018] In a preferred embodiment of the invention, the glass substrate is a soda-lime glass. The use of soda-lime glass allows the bird-friendly glass to achieve a higher reflection effect when used in combination with Low-E glass.

[0019] In a preferred embodiment of the invention, the visible region transmittance of the glass is 85% or more.

[0020] In a preferred embodiment of the invention, the ratio of a first optical ratio to a second optical ratio is in the range of 0.9 to 1.25. This ensures that the visible region transmittance value is maintained, and a structurally strong glass coating is obtained. In a possible embodiment, the optical ratio is in the range of 1 to 1.2, more preferably 1.13.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 schematically shows the example embodiments of the bird-friendly glass subject to the invention.

[0023] Figure 2 shows the scanning electron microscope image of the bird-friendly glass subject to the invention.

[0024] Figure 3 shows the optical curve of the bird-friendly glass subject to the invention on a graph.

[0025] Figure 4 schematically shows an example application of the bird-friendly glass subject to the invention on a building.

[0026] DETAILED DESCRIPTION OF THE INVENTION In this detailed description, the development subject to the invention is described without any limitations and with references to examples solely for the purpose of better explaining the subject.

[0027] A glass substrate includes glass sublayers, and at least one of the sublayers is coated with an ultraviolet (UV) reflective coating to reflect UV radiation so that the bird can see it more easily. In a preferred embodiment, a UV-reflective coating is provided on an exterior surface of the glass exposed to the atmosphere, making it more visible to birds. By making the glass more visible to birds in this way, bird collisions and therefore bird deaths can be reduced. In some example arrangements, the first substrate uses a solar management coating (e.g., Low-E coating) to block at least some infrared (I R) radiation and a UV reflective coating to reflect UV radiation to make the window more visible to birds. In some example arrangements to reduce bird collisions, the Low-E coating may have an emissivity (En) not greater than 0.10 and / or a sheet resistance (Rs) not greater than 8 ohms / square. In certain example arrangements, the UV reflective coating can block at least 38% of UV radiation in the 350-440 nm range, preferably at least 40%, more preferably at least 55%, most preferably at least 60%, and possibly at least 65%. This makes the glass more visible to birds, thereby increasing the UV reflection of the window unit for commercial or residential applications to prevent or reduce bird collisions. Here, the use of such coatings improves the performance of the glass or window by increasing UV reflection beyond the normal limits of uncoated float glass in the 300-440 nm range.

[0028] To further reduce bird collisions, the UV reflective / blocking coating can be patterned on the glass (e.g., in a grid pattern or parallel line pattern), making it more visible to birds. Additionally, the glass preferably has a visible transmission of at least about 50%, more preferably at least about 60%, and most preferably at least about 65% or at least about 70%. Monolithic coated products with only the coating on a glass substrate can have a visible transmission of at least about 70%, more preferably at least about 80%, and most preferably at least about 85%. Also, the film-side UV reflection can be at least 38%, more preferably at least 40%, more preferably at least 55%, most preferably at least 60%, and possibly at least 65%. Additionally, a film-side visible reflection of less than about 20%, more preferably less than about 15%, and most preferably less than about 10%, can be achieved. Therefore, the film-side UV reflection can be at least about 4 times, more preferably at least about 5 times, most preferably at least about 8 times, and possibly at least 10 times higher than the film-side visible reflection of the monolithic coated product.

[0029] In the table above, T defines transmittance; Rc defines coating side reflection; Ru defines glass side reflection; Tvis defines visible region transmittance. Rvis out defines external reflection; Rvis in defines internal reflection; and Ra defines color fidelity. In the arrangement given as Example 1 , a Low-E coating is applied on a glass substrate (10). The Low-E coating utilizes the coating formulation described in patent publication PCT / TR2022 / 050016, incorporated herein by reference. In the arrangement given as Example 2, a bird-friendly coating is applied to the backside of the Low-E coated substrate. As a result of applying the bird-friendly coating to the backside of the Low-E coated substrate, it has been determined through test results that the transmittance, coating side reflection, glass side reflection, external reflection, internal reflection, color fidelity, and thermal transmittance values remain within suitable limits for the glass's area of use.

[0030] Figure 1 schematically shows the example embodiments of the glass subject to the invention. The glass includes a glass substrate (10). The glass substrate (10) is selected as a soda-lime glass. On the glass substrate (10), a UV reflective coating is provided to reflect UV rays. In an example embodiment, the UV reflective coating includes sequential layers of titanium oxide and silicon oxide. Seven layers are used in the example embodiment. The first layer (20) adjacent to the glass substrate (10) contains titanium oxide. Thanks to titanium oxide, a high refractive index layer is obtained. The second layer (30) adjacent to the first layer (20) contains silicon oxide. Thanks to silicon oxide, a low refractive index layer is obtained. The refractive indices of TiO and SiOx thin films at 550 nm are selected as 2.42 and 1.46, respectively. According to the sequential arrangement, the third layer (40) adjacent to the second layer (30) contains titanium oxide; the fourth layer (50) adjacent to the third layer (40) contains silicon oxide; the fifth layer (60) adjacent to the fourth layer (50) contains titanium oxide; the sixth layer (70) adjacent to the fifth layer (60) contains silicon oxide; and the seventh layer (80) adjacent to the sixth layer (70) contains titanium oxide. An optical filter is obtained with the seven-layer UV reflective coating. In another example embodiment, the UV reflective coating includes sequential layers of titanium oxide, silicon oxide, and silicon oxynitride. The refractive indices of TiOx, SiOx, and SiOxNy thin films at 550 nm are selected as 2.42, 1.46, and 1.91 , respectively. Eleven layers are used in the example embodiment. The first layer (20) adjacent to the glass substrate (10) contains titanium oxide. The second layer (30) adjacent to the first layer (20) contains silicon oxide. According to the sequential arrangement, the third layer (40) adjacent to the second layer (30) contains titanium oxide; the fourth layer (50) contains a first intermediate layer (52) containing silicon oxynitride, a second layer (54) containing silicon oxide, and a third intermediate layer (56) containing silicon oxynitride; the fifth layer (60) adjacent to the fourth layer (50) contains titanium oxide; the sixth layer (70) adjacent to the fifth layer (60) contains a fourth intermediate layer (52) containing silicon oxynitride, a fifth layer (54) containing silicon oxide, and a sixth intermediate layer (56) containing silicon oxynitride; and the seventh layer (80) adjacent to the sixth layer (70) contains titanium oxide. When applying the UV reflective optical filter to the glass, the refractive indices and band gaps of the materials were considered when selecting the metal oxide. To ensure that the designed optical filter does not absorb in the visible region (approximately 400 nm 700 nm), the band gap needs to be higher than ~3.1 eV. In the preferred embodiment, the band gaps of the dielectric materials used are ~3.2 eV for TiO2 and ~8.9 eV for SiO2. The Fresnel Reflection Equation is used to control the reflective properties of the optical filter. An optical filter is obtained by sequentially coating high and low refractive index dielectrics on the glass substrate (10) and determining the film thicknesses according to the wavelength of the light to be reflected during the coatings. As the number of layers increases, the number of interfaces between the high and low refractive index layers also increases, thereby enhancing the filter's selectivity.

[0031] In the coating applied to the glass substrate (10), the optical path of the titanium oxide in the first and seventh layers (20, 80) is determined to be 23 nm. The optical path of the titanium oxide in the third and fifth layers (40, 60) is determined to be 31 nm and 46 nm, respectively. The optical path of the silicon oxide in the second layer (30) is determined to be 108 nm. The optical path of the silicon oxide and silicon oxynitride in the first intermediate layer, second intermediate layer, and third intermediate layer of the fourth layer (50), and in the sixth layer (70) containing the fourth intermediate layer (52) containing silicon oxynitride, the fifth layer (54) containing silicon oxide, and the sixth intermediate layer (56) containing silicon oxynitride, is determined to be 130 nm. The ratio of the optical path value of the silicon oxide in the first layer (20) adjacent to the first layer is named as a first optical ratio (e1 ) and is determined to be 4.7. The ratio of the optical path value of the silicon oxide and silicon oxynitride to the optical path value of the titanium oxide is named as a second optical ratio (e2) and is determined to be 4.13. The ratio of the first optical ratio (e1 ) to the second optical ratio (e2) is 1 .13.

[0032] Figure 2 shows the scanning electron microscope image of the glass subject to the invention. The image obtained under the electron microscope shows an example embodiment with a seven-layer UV coating. The first layer (20) contains titanium oxide, and it is determined under the electron microscope to have a thickness of 18.9 nm. The second layer (30) adjacent to the first layer (20) contains silicon oxide, and it is determined under the electron microscope to have a thickness of 66.5 nm. According to the sequential arrangement, the third layer (40) adjacent to the second layer (30) contains titanium oxide and has a thickness of 25.8 nm; the fourth layer (50) adjacent to the third layer (40) contains silicon oxide and has a thickness of 67.5 nm; the fifth layer (60) adjacent to the fourth layer (50) contains titanium oxide and has a thickness of 23.8 nm; the sixth layer (70) adjacent to the fifth layer (60) contains silicon oxide and has a thickness of 64.5 nm; and the seventh layer (80) adjacent to the sixth layer (70) contains titanium oxide and has a thickness of 19.8 nm. When the optical properties of the obtained glass are examined, it is determined that the visible region transmittance is over 85% and the UV region reflectivity is over 70% (320 nm - 360 nm).

[0033] Figure 3 shows the optical curve of the glass subject to the invention as a graph. The graph shows the values of transmittance (T), coating side reflection (Rc), and glass side reflection (Ru). The optical curve of glass with a bird-friendly coating shows a transmittance value of 90.65, a coating side reflection value of 7.06, and a glass side reflection value of 7.12. In this way, a bird-friendly glass with UV reflective properties is produced in accordance with the transmittance and reflection reference values of glass without bird-friendly coating.

[0034] Figure 4 schematically shows an example application of the glass subject to the invention on a building. The bird-friendly coating described above is applied to the outermost surface of the glass substrate (10). The surface of the glass substrate (10) with the bird-friendly coating faces outward from the building. On the surface of the glass substrate (10) opposite to the surface with the bird-friendly coating, a Low-E coating is applied according to the coating formulation described in patent publication PCT / TR2022 / 050016, incorporated herein by reference. An intermediate space is present between the glass substrate (10) and an adjacent second glass substrate (90). The intermediate space can vary between 9 to 16 mm. Two desiccants (100) are aligned opposite each other within the intermediate space. The desiccants (100) are provided with an inner sealant made of polyisobutylene for internal insulation and an outer sealant made of polysulfide, polyurethane, or silicone for external insulation.

[0035] REFERENCE NUMBERS

[0036] 10 Glass Substrate

[0037] 20 First Layer

[0038] 30 Second Layer 40 Third Layer

[0039] 50 Fourth Layer

[0040] 52 First Intermediate Layer

[0041] 54 Second Intermediate Layer 56 Third Intermediate Layer

[0042] 60 Fifth Layer

[0043] 70 Sixth Layer

[0044] 72 Fourth Intermediate Layer

[0045] 74 Fifth Intermediate Layer 76 Sixth Intermediate Layer

[0046] 80 Seventh Layer

[0047] 90 Second Glass Substrate

[0048] 100 Desiccant

[0049] E1 First Optical Ratio E2 Second Optical Ratio

Claims

CLAIMS1 . A glass for reducing or preventing bird collisions comprising a glass substrate (10) and a UV reflective coating provided on the glass substrate (10), characterized by the UV reflective coating being fully coated on the glass substrate (10); the UV reflective coating reflecting at least 70% in the 320-360 nm range and comprising multiple layers of titanium oxide and silicon oxide or titanium oxide, silicon oxide, and silicon oxynitride in sequence.

2. The glass according to claim 1 , wherein a first layer (20) adjacent to the glass substrate (10) contains titanium oxide.

3. The glass according to claim 2, wherein a second layer (30) adjacent to the first layer (20) contains silicon oxide.

4. The glass according to claim 2 or 3, wherein a third layer (40) adjacent to the second layer (30) contains titanium oxide.

5. The glass according to any of claims 2-4, wherein a fourth layer (50) adjacent to the third layer (40) contains silicon oxide or a mixture of silicon oxide and silicon oxynitride.

6. The glass according to any of claims 2-5, wherein a fifth layer (60) adjacent to the fourth layer (50) contains titanium oxide.

7. The glass according to any of claims 2-6, wherein a sixth layer (70) adjacent to the fifth layer (60) contains silicon oxide or a mixture of silicon oxide and silicon oxynitride.

8. The glass according to any of claims 2-7, wherein a seventh layer (80) adjacent to the sixth layer (70) contains titanium oxide.

9. The glass according to any of the preceding claims, wherein the total thickness of the first, second, third, fourth, fifth, sixth, and seventh layers (20, 30, 40, 50, 60, 70, 80) is in the range of 265-300 nm.

10. The glass according to any of the preceding claims, wherein the glass substrate (10) is a soda-lime glass.

11. The glass according to any of the preceding claims, wherein the visible region transmittance of the glass is 85% or more.

12. The glass according to any of the preceding claims, wherein a first optical ratio (E1) to a second optical ratio (E2) is in the range of 0.9 to 1.25.

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