Glazing designed to prevent bird collisions

Abstract

The present invention relates to glazing suitable for forming a wall of a building, this glazing being composed of at least one glass substrate, a first face of a first of these glass substrates forming the external face of the glazing, intended to be oriented outwards. A pattern visible to birds is affixed to one of the faces of the glass substrate(s) that do not constitute the external surface of the glazing. According to the invention, the external face of the glazing has a coating having anti-reflective properties.

Description

Title of the invention: Glazing adapted to prevent bird collisions

[0001] The present invention relates to glazing, and more particularly to glazing forming part of the exterior walls of buildings.

[0002] It relates in particular to such glazing having adaptations aimed at preventing bird collisions with the glazing.

[0003] Glazing is commonly used to form an exterior wall of a building. It can be used in glazed openings, allowing outside light to enter the building, or as cladding covering the walls of the building, in order to give it a uniform exterior appearance.

[0004] The glazing forming the exterior walls of buildings can sometimes cause bird collisions. Indeed, birds may not see the glazing and try to fly through it. In other cases, they may try to reach a point they see reflected in the glazing. In these situations, they collide at full speed with the glazing, which can cause injury or death. Such collisions are, of course, detrimental to the preservation of wildlife, and particularly to threatened and / or protected bird species. In addition to the harm caused to the birds and the problem of species protection, such collisions can lead to damage or soiling of the glazing, the undesirable presence of bird carcasses at the foot of buildings, and an inconvenience for people witnessing the collision.

[0005] It is known to apply adaptations to the glazing forming the exterior walls of buildings specifically designed to make this glazing more visible to birds, in order to avoid such collisions and to protect the birds. These adaptations include, in particular, the application of visible patterns, in wavelengths visible to birds and especially UV, which are applied to one of the faces of one of the glass substrates constituting the glazing. Document US2013003208Al shows examples of such adaptations.

[0006] It is possible to apply these patterns to the outer surface of the glazing, that is, when the glazing is composed of several superimposed glass substrates, to the outer surface of the glass substrate forming the outer surface of the glazing. Such a configuration offers good visibility of the patterns by birds and exhibits good performance in terms of reducing the number of bird collisions with the glazing.

[0007] This configuration, however, has drawbacks. For example, the patterns applied to the outer surface of the glazing are exposed to the elements, which can damage them. over time. Furthermore, the presence of these patterns on the outer surface of the glass can cause dirt to adhere more easily to the glass, thus degrading its aesthetic appearance.

[0008] Application WO2015 / 181542 describes a configuration in which a discontinuous anti-reflective coating is applied to the outer surface of the glazing in the form of patterns such as a plurality of bands or dots, so as to generate a contrast between areas covered by the coating and bare areas of the glass surface, a contrast visible to birds. The spaces between the patterns can also be filled with a UV-reflective coating, so as to further improve the contrast for birds whose eyes are sensitive to UV light. Again, such a configuration does not appear to be durable over time under the effects of weathering or to create a surface conducive to the accumulation of dirt.

[0009] The present invention aims to overcome these drawbacks of the prior art.

[0010] In particular, the present invention aims to provide glazing suitable for being used as an element of the exterior wall of a building, which is configured to effectively prevent the risk of bird collisions.

[0011] Another objective of the invention is to provide such glazing in which the features enabling the avoidance of bird collisions are durable over time, and not very sensitive to weathering.

[0012] Yet another objective of the invention is to provide such glazing in which the features enabling the avoidance of bird collisions do not entail a risk of soiling of the glazing.

[0013] These objectives, as well as others that will become clearer later, are achieved according to the invention by means of glazing whose bird-visible patterns are applied to one face of one of the glass substrates of the glazing, which does not constitute the outer face of the glazing, unlike the prior art. It can preferably be applied to the inner face of the glass substrate whose outer face constitutes the outer face of the glazing, without excluding its presence on one of the other inner faces of the other glass substrates, when the glazing comprises several glass substrates in the form of multiple panes. According to the invention, to increase the effectiveness of such an embodiment, the natural reflection of the outer face of the outer glazing is reduced by applying an anti-reflective coating in the form of a continuous layer, i.e., without patterns.

[0014] Suitable for forming a wall of a building, a glazing unit according to the invention consists of at least one glass substrate, a first face of a first of these glass substrates forming the external face of the glazing unit, that is to say, intended to be oriented outwards. According to the invention, a pattern visible to birds is affixed to one of the faces of the glass substrate(s) that does not constitute the external surface of the glazing unit. According to the invention, the external face of this glazing on the contrary bears a coating having anti-reflective (or anti-reflective) properties in the visible range (i.e. between 380 and 780 nm).

[0015] By anti-reflective coating, we mean a layer or stack of layers, preferably covering the entire external glass surface of the glazing, without the presence of patterns, capable of reducing light reflection (and therefore increasing light transmission) in the visible range as described in more detail later in the description.

[0016] In such glazing, the absence of reflection, or reduced reflection, on the outer surface of the glazing allows the pattern applied to another surface of a glass substrate constituting the glazing, in particular the other surface of the same glass substrate supporting the anti-reflective coating, to be more visible to birds. Such glazing therefore makes it possible to very effectively reduce the risk of birds colliding with the glazing, even though the pattern is not applied to the outer surface of the glazing.

[0017] In particular, according to the invention, the presence of an anti-reflective coating on the outer surface allows for improved visibility of the patterns by birds, even if these patterns are located on an inner surface of the glazing. Furthermore, the positioning of the pattern on a surface distinct from the outer surface of the glazing protects it from the elements. It can thus be more durable and does not provide a surface for dirt to adhere to and potentially come into contact with the outer surface of the glazing.

[0018] Preferably, the pattern is affixed to the inner face of the first glass substrate, the outer face of which constitutes the outer surface of the glazing.

[0019] Such a configuration allows for very good visibility of this pattern by birds. It should be noted that it does not necessarily preclude other pattern elements from being affixed, in a complementary manner, to faces of other glass substrates of the glazing.

[0020] According to a particular embodiment of the invention, the second face of the first glass substrate also carries a coating having anti-reflective properties.

[0021] Preferably, the coating having reflective properties consists of at least one thin layer of a transparent material having a lower optical index than the optical index of the first glass substrate.

[0022] It is known that the reflectance level of a transparent glass surface is primarily determined by the contrast in refractive index between the surface and that of air (equal to 1). To obtain antireflective properties from a reflective surface, it is known to deposit a transparent layer or a stack of transparent layers (here called an antireflective coating or coating with antireflective properties) which provides specific optical behavior, in which light waves Reflected light rays are out of phase with the incident waves when reflection occurs at the air / coating interface and at the coating / glass interface. Therefore, an anti-reflective coating is defined here as any coating capable of reducing the reflection of visible light (i.e., light with wavelengths between 380 and 780 nm) on a glass surface, specifically by at least 1%, or even at least 2%, or at least 3% (i.e., reducing an initial reflection of visible light from 4% to less than 3%, less than 2%, or even less than 1%). Light transmission and reflection at the surface of a glass substrate on which such a coating is applied can be measured according to standard EN 410 (2011-04).

[0023] There are different possibilities for forming such coatings.

[0024] According to a first embodiment, the coating comprises, or preferably is made up of, a porous silicon oxide layer. These layers can be nanoporous, mesoporous, or macroporous.

[0025] These coatings are characterized by the presence of a certain amount of air trapped in the porosity. The porosity is created by the imperfect compactness of the nanoparticles, by the removal of porogens such as PMMA beads present within the silica layer and then removed by heating or by acid / alkaline etching. Such coatings are described, for example, in the following publications: Chen et al., Journal of Sol-Gel Science and Technology 19, 77-82, 2000; Kocs et al., Ceramics International 48 (2022) 4165-4171; Zheng et al., Ceramics International 46 (2020) 18623-18631; and Yoo et al., Vol. 9, No. 11 / 1 November 2019 / Optical Materials Express or patent publications WO2013024226 or EPI 679291.

[0026] Several techniques currently exist for obtaining porous layers, in particular through the use of porogens:

[0027] - either by using a sacrificial organic porogen that burns on quenching, such as as previously stated,

[0028] - either by using a "durable" porogen, of the hollow nanometric bead type and in In such a case, heat treatment is not necessary.

[0029] According to another alternative, the invention also uses an anti-reflective coating consisting of a stack of layers with different refractive indices (generally an alternation of high / low refractive index layers) in order to obtain a phase shift of the reflected light waves. This type of product is called a multilayer or interference anti-reflective coating. These coatings are generally developed to obtain high-performance anti-reflective properties over a wider range of wavelengths.

[0030] For the purposes of this invention, "stacking" means a set of at least two superimposed layers, starting from the surface of a glass substrate.

[0031] Preferably, the coating having reflective properties comprises a stacking of a plurality of thin layers of transparent materials having different optical indices, in particular an alternation of layers with refractive index (at 550 nm) alternately higher and lower than the previous one, from the surface of the glass the thicknesses of said layers being configured to decrease light reflection at the surface of the glass.

[0032] Said anti-reflective coating may thus comprise a stack of at least two layers of different refractive indices, including a layer with a refractive index at 550 nm less than 1.6 and a layer with a refractive index greater than 1.6, the thicknesses of said layers being configured to reduce light reflection at the surface of the glass.

[0033] In particular, according to a preferred embodiment of the invention, the stack with anti-reflective properties comprises and preferably is made up of, from the surface of the transparent substrate:

[0034] - a first layer with a refractive index ni at 550 nm between 1.8 and 2.5 of preferably between 1.8 and 2.2, and with a geometric thickness el between 5 and 50 nm, preferably between 10 and 30 nm;

[0035] - a second layer with a refractive index n2 at 550 nm between 1.35 and 1.65 and geometric thickness e2 between 5 and 50 nm, preferably between 15 and 45 nm;

[0036] - a third layer of geometric thickness e3 at 550 nm with refractive index n3 between 1.8 and 2.5 preferably between 1.8 and 2.2 between 50 and 120 nm and preferably between 60 and 100 nm;

[0037] - a fourth layer, with a refractive index n4 between 1.35 and 1.65 and geometric thickness e4 between 40 and 130 nm, in particular between 60 and 120 nm.

[0038] Preferably the low index layers (2nd and 4th layers) comprise silicon oxide or silicon and aluminum oxide.

[0039] Preferably, the high index layers (1st and 3rd layers) comprise and preferably are made of silicon nitride, aluminum nitride or a mixture of silicon and aluminum nitride, or even of a zinc and tin oxide, in particular of general formula SnxZnyOz, in which the mass ratio Sn / Zn is preferably between 50 / 50 and 85 / 15 and more preferably between 55 / 45 and 75 / 25.

[0040] At least one of said thin layers is made up mainly of silicon dioxide, that is to say it comprises more than 50% by weight and preferably more than 80% or even more than 90% by weight of silicon oxide.

[0041] According to an advantageous embodiment of the invention, the coating with anti-reflective properties in The visible light also exhibits reflective properties in the ultraviolet. In particular, such a coating can comprise the same sequence as previously described, with a thickness e3 between 120 and 180 nm, preferably between 140 and 160 nm.

[0042] According to the invention, said motif can be formed by a plurality of distinct elements, of a color visible to birds.

[0043] For example, said pattern may be formed by an enamel on one of the faces of said or one of said glass substrates that do not constitute said external surface of the glazing, for example in the form of enamel dots or strips. Alternatively, the pattern may be obtained by etching the glass surface of an internal face of the glazing by any known technique such as acid etching, sandblasting, or laser ablation.

[0044] According to another embodiment, the patterns on an inner face of the glazing can be made of a material that is transparent to visible light but opaque, or that reflects UV radiation, particularly between 280 nm and 380 nm. Such an embodiment has the advantage that the texture of the inner surface is invisible to the human eye but remains perfectly perceptible to birds. For example, the material constituting the pattern can be titanium oxide, particularly in the form of strips or dots, for example with a thickness between 5 and 50 nm.

[0045] The invention will be better understood upon reading the following description of preferred embodiments, given by way of simple figurative and non-limiting example, and accompanied by the figures, among which: - Fig. 1 is a front view of a portion of glazing according to an embodiment of the invention, adapted to avoid bird collisions. - Fig. 2 is a schematic cross-sectional view of a portion of the external glass substrate of a glazing according to a solution not in accordance with the present invention, having a pattern similar to that of the glazing in Fig. 1. - Fig. 3 is a schematic cross-sectional view of a portion of the external glass substrate of the glazing of Fig. 1. - Fig. 4 is a schematic cross-sectional view of a portion of the external glass substrate of a glazing according to another embodiment of the invention, having a pattern similar to that of the glazing in Fig. 1.

[0046] Figure 1 is a schematic, front-view representation of a portion of a glazing unit 1, suitable for forming at least part of an external wall of a building, which has been adapted to prevent bird collisions. The glazing unit 1 partially shown in Figure 1 can be a single glazing unit comprising only one glass substrate, but also a multiple glazing unit consisting of several glass substrates separated from each other by gas gaps in a conventional configuration, or bonded by A thermoplastic sheet of the PVB type (this is then referred to as laminated glass). Only the first glass substrate is shown in [Fig. 1]. In all cases, this first glass substrate, forming the surface of the glazing and intended to face outwards, constitutes the external glass substrate, or first glass substrate 11 in [Fig. 2]. For example, in the case of single glazing, the first glass substrate 11 is the only substrate present.

[0047] According to the invention, a pattern, which can take any shape and thickness perceptible to a bird, is affixed to at least one face of at least one of the glass substrates constituting the glazing, in particular to face 2 (inner face) of the glass substrate 11, this pattern preferably comprising a plurality of separate elements. In the embodiment shown, this pattern 2 forms a plurality of points 21, which, for example, each have a diameter of 6 mm and are spaced 50 mm apart. These points can be made of a material exhibiting visible coloration, including white or black, or any other wavelength visible to birds. Alternatively, they can be made of a material transparent to visible radiation but reflecting (at least partially) ultraviolet radiation, particularly in the 280-380 nanometer range, visible to birds.

[0048] In the embodiment shown in the figures, these points are created by depositing a layer of enamel on the inner face of the first glass substrate of the glazing. In other embodiments, such points can be created by any other process known to those skilled in the art, for example by localized sandblasting of one face of one of the glazing substrates, making the sandblasted portion of the surface visible.

[0049] According to other possible embodiments, the motifs may have forms other than a set of points. They may, for example, consist of a set of lines, for example parallel to each other.

[0050] It has been demonstrated that such patterns make the glazing more visible to birds, and that their presence on the glazing makes it possible to significantly reduce the number of bird collisions with it.

[0051] Figure 2 is a schematic representation of a first glass substrate 11, forming the outward-facing surface of a portion of glazing similar to glazing 1 of Figure 1, the bird-collision protection of which was carried out according to a process not in accordance with the present invention. In this glazing, the glass substrate 11 has an external face 31, intended to face outwards and form the external face of the glazing. The internal face 32 of this glass substrate 11, opposite the external face 31, bears a pattern 2 intended to be seen by birds, which is constituted by a plurality of points 21 as described above.

[0052] When incident sunlight from the outside, symbolized by arrow 51, reaches the glazing, part of this incident light 51 is reflected by the face external 31 of the first glass substrate 11. This reflected light is symbolized by arrow 52. Part 53 of the incident light which passes through the first glass substrate 11 can illuminate the points 21 of the pattern 2, the image of which, symbolized by arrow 54, is visible to the birds.

[0053] However, it appears that this image 54 of the pattern 2 is partially masked, for the birds, by the light reflected 52 from the incident light on the external face 31 of the first glass substrate 11, which greatly reduces the anti-collision performance of the pattern 2.

[0054] Figure 3 is a schematic cross-sectional view of a first glass substrate 11 forming the outer layer of the glazing portion 1 shown in Figure 1. The glazing according to the invention can be conventionally made up of a plurality of glass substrates bonded to one another as described above. It can also be made up of a single glass substrate. The schematic representation in Figure 3 shows only the first glass substrate 11 of this glazing 1, the outer face 31 of which is intended to face outwards and form the outer face of the glazing 1.

[0055] The inner face 32 of this first glass substrate 11, opposite the outer face 31, bears the pattern 2 intended to be seen by birds, which consists of a plurality of points 21. In the embodiment shown, these points 21 are formed by a deposit of black enamel on the inner face 32 of the first glass substrate 11. These points may, for example, each have a diameter of 6 mm and be spaced 50 mm apart.

[0056] The invention can however be implemented with other types of patterns visible to birds as described above and / or which are known to a person skilled in the art.

[0057] The presence of pattern 2 on the inner face 32 of the first glass substrate 11 ensures that this pattern 2 is not in direct contact with the weathering that may affect the outer face 31 of the glazing 1. This pattern 2 is therefore not at risk of being degraded over time by the weathering. Furthermore, it is not at risk of becoming a surface for soiling that may originate from outside the glazing 1.

[0058] According to the invention, the outer face 31 of the first glass substrate 11, which forms the outer face of the glazing 1, is coated with a continuous coating 4 having anti-reflective properties. The deposition of coatings with anti-reflective properties, or "anti-reflective coating," is well known to those skilled in the art, particularly under the name "anti-reflective treatment." It may, for example, consist of deposition of one or more layers of a transparent material, as described above, the thickness of each layer and the refractive index of the material used to form this layer being chosen so as to increase the proportion of incident light that is transmitted and to decrease the proportion that is reflected.

[0059] In [Fig.3], arrow 51 schematically represents the incident light coming from outside, arriving on the glazing 1. The external face 31 of the first glass substrate 11 being coated with an anti-reflective coating 4, a very large part of the incident light 51 passes through the first glass substrate 11. Only a very small part of the incident light 51, which is symbolized by arrow 52, ​​is reflected by the external face 31 of the first glass substrate 11.

[0060] A very large part of the incident light 51, symbolized by the arrow 53, therefore illuminates the motif 2, placed on the inner face 32 of the first glass substrate 11. The image of this motif 2, symbolized by the arrow 54, is thus very clearly visible from the outside by the avian population, without this image 54 being masked, in a significant way, by the light reflected 52 on the outer face 31 and the inner surface 32.

[0061] Figure 4 is a schematic cross-sectional view of the first glass substrate 11 forming the external surface of a glazing according to another possible embodiment of the invention. According to this embodiment, the external face 31 and the internal face 32 of the first glass substrate 11 are both covered by coatings with anti-reflective properties, or anti-reflective coatings, 41 and 42 respectively. These two coatings are continuous, that is to say, they cover the glass surface without discontinuity in the form of a uniform coating of substantially the same thickness at every point.

[0062] According to this embodiment, the points 21 constituting the pattern 2 are deposited on the inner face of the first glass substrate 11, over the anti-reflective coating 42. Compared to the embodiment shown in [Fig. 3], this embodiment of the invention makes the pattern 2 even more visible to birds present on the outside of the glazing 1. However, the inventors have identified that the presence of the anti-reflective coating 42 on the inner face 32 of the first glass substrate 11 does not significantly improve the visibility of the pattern from the outside, and may even degrade this visibility.

[0063] By way of illustration of the advantages of the present invention, the inventors have carried out "tunnel" test simulations allowing the calculation of visibility scores, under identical conditions, of the patterns 2 made in black enamel in glazings whose configuration corresponds, respectively, to that of [Fig.2] and [Fig.3] described above.

[0064] In both configurations, the glass substrate used is a 4 mm thick clear glass on which a four-layer anti-reflective coating with the following composition has been deposited by magnetron, starting from the surface of the glass:

[0065] Layer 1: Si3N4 with a thickness of 21 nm,

[0066] Layer 2: SiO2 with a thickness of 26 nm,

[0067] Layer 3: SnxZnyOz with a thickness of 60 nm, and a mass ratio of Sn / Zn of approximately 70 / 30, as measured by electron probe microanalyzer.

[0068] Layer 4: SiO2 with a thickness of 94 nm.

[0069] The so-called "tunnel" test consists of positioning the glass being studied in a tunnel, throwing birds into it and noting how many of them avoided it.

[0070] More specifically, the performance of the glazing was evaluated according to the principles described in the publications “Evaluating the relative effectiveness of patterns on glass as deterrents of bird collisions with glass”, Global Ecology and Conservation, Volume 20, October 2019, e00795” and “Hâstad O, Ôdeen A. 2014. A vision physiological estimation of ultraviolet window marking visibility to birds. PeerJ 2:e621” and using the Birdvis simulation tool available on the internet at: http: / / ec2-3-140-67-204.us-east-2.compute.amazonaws.com.

[0071] The test results are shown in the table below. A positive score is considered to indicate a probability of success in the tunnel test of at least 75%. Conversely, a negative value indicates that the glazing does not pass the tunnel test and therefore results in insufficient visibility of the pattern for birds outside.

[0072] [Tables 1] Pattern Visibility Score (Rext) Example according to: Configuration Visible UV Figure 1 -Email pattern face 2 -2.6 -2.6 Figure 2 -AR face 1 -Email pattern face 2 7.6 7.8

[0073] The results obtained show positive scores for the glazing configurations according to [Fig.2] according to the invention, which corresponds to an acceptable visibility of the pattern for birds located outside, unlike the glazing according to [Fig.1].

Claims

Demands

1. Glazing suitable for forming at least part of a wall of a building, said glazing being made up of at least one glass substrate, a first face of a first of said glass substrates forming the external face of the glazing, intended to be oriented outwards, in which a pattern visible to birds is affixed to one of the faces of said or one of said glass substrates which does not constitute said external surface of the glazing and in which said external face of said glazing is coated with a coating having anti-reflective properties of visible light.

2. Glazing according to the preceding claim, wherein said pattern is deposited on the second face of said first glass substrate.

3. Glazing according to any one of the preceding claims, characterized in that the second face of said first glass substrate bears a second coating having anti-reflective properties.

4. Glazing according to any one of the preceding claims, wherein said coating having reflective properties is made up of at least one layer of a transparent material having a lower optical index than the optical index of said first glass substrate.

5. Glazing according to the preceding claim, wherein said coating having reflective properties comprises a porous silicon oxide layer.

6. Glazing according to claims 1 to 3, wherein said anti-reflective coating comprises a stack of at least two layers of different refractive indices, including a layer with a refractive index at 550 nm less than 1.6 and a layer with a refractive index greater than 1.6, the thicknesses of said layers being configured to decrease light reflection at the surface of the glass.

7. Glazing according to the preceding claim, wherein the stacking with anti-reflective properties comprises, from the surface of the transparent substrate: - a first layer with a refractive index ni at 550 nm between 1.8 and 2.5, and a geometric thickness el between 5 and 50 nm; - a second layer with a refractive index n2 at 550 nm between 1.35 and 1.65 and a geometric thickness e2 between 5 and 50 nm; - a third layer with a refractive index n3 at 550 nm between 1.8 and 2.5 and a geometric thickness e3 between 50 and 120 nm; - a fourth layer, with a refractive index n4 between 1.35 and 1.65 and a geometric thickness e4 between 40 and 130 nm.

8. Glazing according to any one of the preceding claims, characterized in that at least one of said thin layers is made up predominantly of silicon dioxide.

9. Glazing according to any one of the preceding claims, characterized in that said coating further exhibits anti-reflective properties against UV radiation.

10. Glazing according to the preceding claim characterized in that said coating further exhibits anti-reflective properties for UV radiation in the range of 280-380 nm.

11. Glazing according to any one of the preceding claims, characterized in that said pattern is formed by a plurality of distinct elements, of a color visible to birds.

12. Glazing according to any one of the preceding claims, characterized in that said pattern is formed by the deposition of an enamel on one of the faces of said or one of said glass substrates which do not constitute said external surface of the glazing.

13. Glazing according to any one of the preceding claims, characterized in that said pattern is formed by the deposition of an enamel on face 2 of said glazing, numbering the faces from the outside in

14. Glazing according to any one of the preceding claims, characterized in that said pattern is formed by the deposition of an enamel on face 3 of said glazing, numbering the faces from the outside in.

Images