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 implemented in bay windows, allowing outside light to penetrate the building, or as cladding covering the walls of the building, in order to give it a uniform exterior appearance.

[0004] Glazing forming the exterior walls of buildings can sometimes cause bird collisions. Indeed, birds may not see the glazing, and try to pass through it. In other cases, they may try to reach a point that they see in a reflection returned by the glazing. In these situations, they collide, at full speed, with these glazings, which can cause them injuries or death. Such collisions are of course detrimental to the preservation of wildlife, and particularly of threatened and / or protected bird species. In addition to the damage caused to birds and the problem of species protection, such collisions can lead to damage or soiling of the glazing, the harmful presence of bird corpses at the foot of buildings, and inconvenience for people witnessing the collision.

[0005] It is known to apply adaptations to the glazing forming the exterior walls of buildings specifically aimed at making these glazings 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 in particular UV, which are affixed 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 affix these patterns to the external face of the glazing, that is to say, when the glazing is composed of several superimposed glass substrates, on the external face of the glass substrate forming the external face of the glazing. Such a configuration offers good visibility of the patterns by birds, and has good performance, in terms of reducing the number of bird collisions on the glazing.

[0007] This configuration does, however, have drawbacks. Thus, the patterns affixed to the external face of the glazing are subject to bad weather, which can damage them. over time. Furthermore, the presence of these patterns on the external face of the glazing can cause dirt to adhere better to this glazing, which degrades its aesthetic appearance.

[0008] Application WO2015 / 181542 describes a configuration in which a discontinuous anti-reflective coating is arranged on the external face of the glazing in the form of patterns such as a plurality of strips or studs, so as to generate a contrast between areas occupied by the coating and bare areas of the glass surface, a contrast visible to birds. The spaces left between the patterns can also be occupied by a UV-reflecting coating, so as to further improve the contrast for birds whose eyes are sensitive to UV. Here again, such a configuration does not appear to be durable over time under the action of bad weather or even forms a breeding ground for 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, capable of being used as an element of the exterior wall of a building, which is configured to effectively avoid the risk of bird collision.

[0011] Another objective of the invention is to provide such glazing in which the characteristics making it possible to avoid bird collisions are durable over time, and not very sensitive to bad weather.

[0012] Yet another objective of the invention is to provide such glazing in which the characteristics making it possible to avoid bird collisions do not lead to a risk of soiling the glazing.

[0013] These objectives, as well as others which will appear more clearly subsequently, are achieved according to the invention using a glazing whose patterns visible to birds are affixed to a face of one of the glass substrates of the glazing which does not constitute the external face of the glazing, unlike in the prior art. It can preferably be affixed to the internal face of the glass substrate, the external face of which constitutes the external face of the glazing, without excluding its presence on one of the other internal faces of the other glass substrates, when the glazing comprises several glass substrates in the form of a multiple glazing. According to the invention, to increase the effectiveness of such an embodiment, the natural reflection of the external face of the external glazing is reduced by affixing 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 according to the invention is made up of at least one glass substrate, a first face of a first of these glass substrates forming the external face of the glazing, that is to say intended to be oriented towards the outside. According to the invention, a pattern visible to birds is affixed to one of the faces of the or one of the glass substrates which does not constitute the external surface of the glazing. According to the invention, the external face of this glazing on the contrary carries a coating having anti-reflective (or anti-reflective) properties in the visible range (i.e. between 380 and 780 nm).

[0015] By coating with anti-reflective properties is meant a layer or a stack of layers, preferably covering the entire exterior 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 in the remainder of the description.

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

[0017] In particular, according to the invention, the presence of an anti-reflective coating on the external face allows improved viewing of the patterns by birds, even if these are present on an internal face of the glazing. The position of the pattern on a face separate from the external face of the glazing also allows this pattern to be protected from the weather. It can thus be more durable, and does not provide any attachment to dirt that may come into contact with the external face of the glazing.

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

[0019] Such a configuration allows very good visibility of this pattern by birds. It should be noted that it does not necessarily exclude other elements constituting patterns from being affixed, in a complementary manner, on 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 an optical index lower than the optical index of the first glass substrate.

[0022] It is known that the level of reflection of a transparent glass surface is mainly determined by the contrast of the refractive index existing between the surface and that of the air (equal to 1). To obtain anti-reflective properties from a reflective surface, it is known to deposit there a transparent layer or a stack of transparent layers (here called anti-reflective coating or with anti-reflective property) which provides a specific optical behavior, in which the waves read reflected waves are in phase opposition with the incident waves when the reflection occurs on the air / coating interface and on the coating / glass interface. By coating with anti-reflective properties, we therefore describe here any coating capable of reducing the reflection of visible light (i.e. of wavelength between 380 and 780 nm) on a glass surface, in particular by at least 1%, or even at least 2%, or even 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%). The transmission and light reflection on the surface of a glass substrate on which such a coating is deposited can be measured according to standard EN 410 (2011-04).

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

[0024] According to a first embodiment, the coating comprises or preferably consists of a porous silicon oxide layer. These layers can be nanoporous, mesoporous or even 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 elimination of porogens such as PMMA beads present within the silica layer and then eliminated by heating or by acid / alkaline attack. 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 or Yoo et al., Vol. 9, No. 11 / 1 November 2019 / Optical Materials Express or patent publications WO2013024226 or EPI 679291.

[0026] There are currently several techniques for having porous layers, in particular through the use of porogens:

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

[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, it is also possible to use according to the invention an antireflection coating consisting of a stack of layers of different refractive index (generally an alternation of layers of high / low refractive index) in order to obtain a phase shift of the reflected light waves. This type of product is called multilayer or interference antireflection coating. These coatings are generally developed to obtain very high-performance antireflection properties over a wider range of wavelengths.

[0030] By "stack" in the sense of the present invention, it is necessary to understand a set of at least two superimposed layers, from the surface of a glass substrate.

[0031] Preferably, the coating having reflective properties comprises a stack of a plurality of thin layers of transparent materials having different optical indices, in particular an alternation of layers with a 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 reduce the 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 of less than 1.6 and a layer with a refractive index of 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 consists of, from the surface of the transparent substrate:

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

[0035] - a second layer with a refractive index n2 at 550 nm of between 1.35 and 1.65 and of 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 of 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 of 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 consist of silicon nitride, aluminum nitride or a mixture of silicon and aluminum nitride, or even a zinc and tin oxide, in particular of general formula SnxZnyOz, in which the Sn / Zn mass ratio 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 consists mainly of silicon dioxide, that is to say that 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 also has reflection properties in the ultraviolet. In particular, such a coating may comprise the same sequence as previously described, with the difference of a thickness e3 of between 120 and 180 nm, preferably of between 140 and 160 nm.

[0042] According to the invention, said pattern 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 which do not constitute said external surface of the glazing, for example in the form of enamel spots 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, laser ablation.

[0044] According to another embodiment, the patterns on an internal face of the glazing may be made of a material or material transparent to visible radiation but opaque or reflecting UV radiation, in particular between 280 nm and 380 nm. Such an embodiment has the advantage that the texturing of the internal surface is invisible to the human eye but remains perfectly perceptible to birds. For example, the material constituting the pattern may be titanium oxide, in particular in the form of a strip or studs, for example with a thickness of between 5 and 50 nm.

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

[0046] [Fig. 1] is a schematic representation, in front view, of a portion of a glazing unit 1, capable of forming at least part of an external wall of a building, which has been adapted to prevent bird collisions. The glazing unit 1 partially represented in [Fig. 1] may be a single glazing unit comprising only a single glass substrate but also a multiple glazing unit consisting of several glass substrates spaced from each other by gas blades according to a conventional configuration, or even bonded by a thermoplastic sheet of the PVB type (this is then referred to as laminated glazing). Only the first glass substrate is shown in [Fig.l]. In all cases, this first glass substrate, forming the surface of the glazing and intended to be turned 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 by a bird, is affixed to at least one of the faces of at least one of the glass substrates constituting the glazing, in particular on face 2 (internal 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 from each other by a distance of 50 mm. These points can be made of a material having a coloration in the visible, including white or black, or in any other wavelength visible to birds. Alternatively, they can be made of a material transparent to visible radiation but reflecting (at least in part) ultraviolet rays, in particular in the 280-380 nanometer range, visible to birds.

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

[0049] According to other possible embodiments, the patterns may have other shapes 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 glazing more visible to birds, and that their presence on glazing makes it possible to significantly reduce the number of bird collisions on it.

[0051] [Fig. 2] is a schematic representation of a first glass substrate 11, forming the outward-facing surface of a portion of a glazing similar to the glazing 1 of [Fig. 1], the bird-proofing treatment of which has been carried out according to a method not in accordance with the present invention. In this glazing, the glass substrate 11 has an external face 31, intended to be facing outwards and to 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 previously.

[0052] When the incident sunlight coming from outside, symbolized by the arrow 51, arrives on the glazing, a 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 the arrow 52. The 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 the arrow 54, is visible to birds.

[0053] It appears, however, that this image 54 of the pattern 2 is partially masked, for the birds, by the reflected light 52 of 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] [Fig. 3] is a schematic sectional view of a first glass substrate 11 forming the outer layer of the glazing portion 1 shown in [Fig. 1]. The glazing according to the invention may be constituted, in a conventional manner, by a plurality of glass substrates bonded to each other as described previously. It may also be constituted by a single glass substrate. The schematic representation of [Fig. 3] shows only the first glass substrate 11 of this glazing 1, the outer face 31 of which is intended to be turned towards the outside and to form the outer face of the glazing 1.

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

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

[0057] The presence of the pattern 2 on the internal face 32 of the first glass substrate 11 ensures that this pattern 2 is not in direct contact with the weather that may strike the external face 31 of the glazing 1. This pattern 2 therefore does not risk being degraded, over time, by the weather. Furthermore, it does not risk serving as a support for dirt that may come from the outside of the glazing 1.

[0058] According to the invention, the external face 31 of the first glass substrate 11, which forms the external 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, in particular under the name of “anti-reflective treatment”. It may for example consist of a deposition of a layer or a plurality of layers of a transparent material, as described previously, the thickness of each layer and the index of the material used to form this layer being chosen so as to increase the portion of the incident light which is transmitted, and to reduce the reflected portion.

[0059] In [Fig. 3], the arrow 51 schematically represents the incident light coming from the 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 incident light 51, which is symbolized by the 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 pattern 2, placed on the internal face 32 of the first glass substrate 11. The image of this pattern 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 manner, by the reflected light 52 on the external face 31 and the internal surface 32.

[0061] [Fig. 4] is a schematic sectional view of the first glass substrate 11 forming the external surface of a glazing unit 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, respectively 41 and 42. These two coatings are continuous, that is to say they cover the glass surface without discontinuity in the form of a uniform coating and substantially of the same thickness at all points.

[0062] According to this embodiment, the points 21 constituting the pattern 2 are deposited on the internal 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 it possible to make the pattern 2 even more visible to birds present on the external side of the glazing 1. However, it has been identified by the inventors that the presence of the anti-reflective coating 42 on the internal face 32 of the first glass substrate 11 does not significantly improve the visibility of the pattern from the outside, and could degrade this visibility.

[0063] By way of illustration of the advantages of the present invention, the inventors carried out “tunnel” test simulations making it possible to calculate visibility scores, under identical conditions, of the patterns 2 made of black enamel in glazing whose configuration corresponds, respectively, to that of [Fig.2] and [Fig.3] described previously.

[0064] In both configurations, the glass substrate used is a 4 mm thick clear glass on which a four-layer anti-reflective coating has been deposited by magnetron having the following composition, 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 Sn / Zn mass ratio of approximately 70 / 30, as measured by microprobe (Electron Probe Microanalyzer),

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

[0069] The so-called "tunnel" test consists of positioning the glazing studied in a tunnel, throwing the 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 following table shows the test results. It is considered that a positive score leads to a probability of success in the tunnel test of at least 75%. On the contrary, a negative value constitutes an indication that the glazing does not pass the said tunnel test and therefore to insufficient visibility of the pattern for birds located 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.l].

Claims

Claims

1. Glazing capable of 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 towards the outside, 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, in which 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 carries a second coating having anti-reflective properties.

4. Glazing according to any one of the preceding claims, wherein said coating having reflective properties consists of at least one layer of a transparent material having an optical index lower 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 claim 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 of 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.

7. Glazing according to the preceding claim, in which the stack with anti-reflective properties comprises, from the surface of the transparent substrate: - a first layer with a refractive index ni at 550 nm of between 1.8 and 2.5, and a geometric thickness el of between 5 and 50 nm; - a second layer with a refractive index n2 at 550 nm of between 1.35 and 1.65 and a geometric thickness e2 of between 5 and 50 nm; - a third layer with a refractive index n3 at 550 nm of between 1.8 and 2.5 and a geometric thickness e3 of 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 consists mainly of silicon dioxide.

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

10. Glazing according to the preceding claim, characterized in that said coating also has anti-reflective properties of UV radiation in the range 280-380 μm.

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 to the inside.

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

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