Laminated glass pane having improved spectral reflection

Abstract

The present invention relates to a laminated glass pane (I) at least containing: an outer glass pane (1) with the outer face (1a) and the inner face (1b); an inner glass pane (2) with the outer face (2a) and the inner face (2b); and a polymer layer (3) between the glass pane (1) and glass pane (2); wherein at least one inner face (1b) or outer face (2a) facing the polymer layer (3) has a nanostructure (4) and an IR-reflecting layer (5) on the nanostructure.

Description

[0001] Laminated glass pane with improved spectral reflection

[0002] The present invention relates to a laminated glass pane with improved spectral reflection, which heats up less when exposed to sunlight and transfers less heat to the outside in cold outdoor temperatures.

[0003] Spectral reflection properties of building glazing are playing an increasingly important role. In light of climate change, buildings with efficient construction can make a decisive contribution to achieving global targets for permissible CO2 emissions. Glazing with the appropriate properties, through energy management of the building, can, among other things, lead to less heat buildup in summer and less heat being transmitted to the outside in winter, according to ISO 5001.

[0004] A device with an IR-reflecting coating is known from DE 102015 001 668 A1. The device, in particular for display devices, comprises a first disc-shaped element and a second disc-shaped element, at least one IR-reflecting coating introduced between the first and second disc-shaped elements, and a filler material introduced between the first and second disc-shaped elements. The first and second disc-shaped elements, the IR-reflecting coating, and the filler material form a composite. Preferably, an anti-reflection coating, in particular in the visible wavelength range, is applied to the outer side of the first or the outer side of the first and second disc-shaped elements. The filler material comprises at least two laminating films, at least one first laminating film and one second laminating film, as well as at least one further film.wherein at least one IR-reflecting coating is provided, wherein the IR-reflecting coating is applied to the film, wherein the film is inserted between the at least first and the second laminating film and the IR solar reflectivity in the wavelength range 780 nm to 3000 nm of the device is in the range 45% to 95% and the reflectivity R, VjS in the visual wavelength range 400 nm to 780 nm is less than or equal to 4%.

[0005] The MicroShade® film from MicroShade A / S is well-known in the professional world (Glass + MicroShade Film = Shading for glass facades - How MicroShade is revolutionizing solar protection - GLASWELT). The MicroShade® film is a 0.2 mm thick passive microstructured film that blocks solar energy and allows natural daylight into the building when installed in a glazed building element or in / on a facade pane.

[0006] WO 2009 / 012750 A2 discloses a method and device for laser structuring solar cells. In this process, solar modules are separated into individual solar cells and electrically interconnected in a continuous roll-to-roll process. By increasing the area processed per laser pulse and using conveyor speeds of several meters for the flexible carrier film coated once or multiple times with functional materials, thermally gentle structuring is achieved at high process speeds.

[0007] WO 2008 / 076614 A2 discloses a coated glass sheet having a first surface and an opposite second patterned surface to provide a predetermined pattern on the second surface of the substrate, and a coating over the pattern. The substrate is made of glass and has a metallic appearance.

[0008] The object of the present invention is to provide a laminated glass pane with improved spectral reflection, which heats up less when exposed to sunlight and transfers less heat to the outside in cold outside temperatures.

[0009] The object of the present invention is achieved by the features of the independent patent claims. Preferred embodiments of the invention emerge from the features of the subclaims.

[0010] The object of the present invention is therefore achieved by a laminated glass pane which contains at least

[0011] An outer glass pane with the outside and the inside,

[0012] An inner glass pane with the outside and the inside and

[0013] A polymer layer is provided between the outer glass pane and the inner glass pane, wherein at least one inner side of the outer pane or the outer side of the inner pane facing the polymer layer has a nanostructure and an IR-reflecting layer thereon. The laminated glass pane according to the invention exhibits surprisingly and unexpectedly good spectral reflectance results. The laminated glass pane according to the invention heats up less in sunlight and transfers less heat to the outside at cold outside temperatures than conventional laminated glass panes.

[0014] A particularly preferred embodiment of the invention is a laminated glass pane, wherein the nanostructuring is obtained using the DLIP process on glass substrates. DLIP stands for "Direct Laser Interference Patterning," a holographic process in which two coherent waves are superimposed in such a way that the resulting interference at the focus of the laser pulse enables micro- or nanostructuring of surfaces.

[0015] DLIP is a method for creating repeating patterns on the surface of materials such as glass by exploiting the interference phenomenon of two or more laser beams. To achieve interference, the beam is split by a beam splitter, special prisms, or other elements. The beams are then folded together to form an interference pattern. A sufficiently high laser beam power can thus lead to material removal at the interference maxima through ablation, leaving the material intact at the minimum. In this way, depending on the laser-material interaction, a specific surface structure or microprofile is created. Due to the energy coupling into the surface, in addition to the purely topographical surface design, the material properties (e.g., microstructure, oxidation behavior, and phase formation) can also be influenced by laser structuring.This provides another possibility for the functional design of surfaces.

[0016] The efficiency of energy coupling during laser structuring depends essentially on the absorption behavior of the material surface and can be influenced by the choice of the wavelength from ultraviolet to infrared of the laser system used.

[0017] A particularly preferred embodiment of the invention is a laminated glass pane, wherein the IR-reflecting layer contains at least two metal layers separated by oxide or nitrite-containing layers, and the metal layer contains silver, gold, or aluminum. Another preferred embodiment of the invention is a laminated glass pane, wherein the IR-reflecting coating preferably contains up to three silver layers.

[0018] These are preferably complex double or even triple silver layer systems, in which the sequence of a single silver layer system is repeated and, if necessary, supplemented by additional layers. Such coatings are usually made of reflective metals, such as gold, silver, copper, nickel-chromium, stainless steel, and others. These materials have high reflectivity in the infrared range. Additionally, metal oxides are applied, such as NiCrO. x So-called blocking layers, such as ZnO or SnCh, are used to protect against chemical attack and to improve adhesion.

[0019] According to the invention, two functional Ag layers or three functional Ag layers are used. The layer structure is applied to the nanostructured glass surface. Among others, the following layer structures are used according to the invention.

[0020] Glass / SiSn4 (doped with Al) / ZnO / NiCr subblocker / Ag1 / NiCr overblocker / ZnO / SiSn4 (doped with Al) / ZnO / NiCr subblocker / Ag2 / NiCr overblocker / ZnO / SiSn4 (doped with Al)

[0021] Or

[0022] Glass / SiSn4 (doped with Al) / ZnO / NiCr subblocker / Ag1 / NiCr overblocker / ZnO / SiSn4 (doped with Al) / ZnO / NiCr subblocker / Ag2 / NiCr overblocker / ZnO / SiSn4 (doped with Al) / ZnO / NiCr subblocker / Ag3 / NiCr overblocker / ZnO / SiSn4 (doped with Al)

[0023] According to the invention, SisN4 can be replaced by SiZrN or by ZnSnO.

[0024] According to the invention, the central silver layer has a thickness of 8 nm to 20 nm, preferably 10 nm to 17 nm.

[0025] According to the invention, the thicknesses of the layers are in the following ranges:

[0026] Ag from 8 nm to 20 nm, preferably from 10 nm to 17 nm

[0027] SisN4 from 5 nm to 80 nm, preferably from 10 nm to 70 nm

[0028] ZnO from 5 nm to 15 nm

[0029] NiCr from 0.1 nm to 3 nm A particularly preferred embodiment of the invention is a laminated glass pane, wherein the nanostructuring has a periodicity of 1 pm to 10 pm, preferably from 3 pm to 7 pm, and particularly preferably from 4 pm to 6 pm. The periodicity according to the invention is achieved in the nanostructuring using the DLIP method. With the nanostructuring according to the invention, very good results are achieved in the scattering of the incident sunlight in the laminated glass panes according to the invention.

[0030] A particularly preferred embodiment of the invention is a laminated glass pane, wherein the nanostructuring has a depth of 0.5 pm to 5 pm, preferably 1 pm to 3 pm, and particularly preferably 1.2 pm to 1.6 pm. The depth of the nanostructuring according to the invention is achieved using the DLIP process. The nanostructuring according to the invention achieves very good results in the scattering of incident sunlight in the laminated glass panes according to the invention.

[0031] A further preferred embodiment of the invention is a laminated glass pane, wherein the polymeric layer contains at least one polymer, such as polyvinyl butyral (PVB), reduced-plasticizer PVB, ionoplast, ethylene vinyl acetate (EVA), polycarbonate, polymethyl methacrylate (PMMA), casting resins or transparent adhesives.

[0032] This is predominantly polyvinyl butyral (PVB). Films for interlayers can also be made of the plastic ethylene vinyl acetate (EVA), which is characterized by high temperature resistance, durability, and a certain minimum rigidity even at high temperatures. The thicker the film or the composite as a whole, the greater the resistance to projectiles, bullets, or pressure waves. Therefore, particularly burglar- and bullet-resistant glazing is laminated with interlayers made of polycarbonate or polymethyl methacrylate (PMMA, acrylic, or Plexiglas) to form a complete composite. Cast resins represent a special type of interlayer; they are not processed as film material but are poured between two glass panes where they subsequently harden.

[0033] Another preferred embodiment is a laminated glass pane, wherein the polymeric layer has a thickness of 0.3 mm to 1.6 mm (0.38 mm, 0.76 mm, 1.14 mm or 1.52 mm). With these thicknesses, the films are particularly well suited according to the invention for producing the laminated glass pane according to the invention. Optically clear adhesives are also used according to the invention as an interlayer. In demanding applications that require both transparency and strong contact bonding, transparent adhesives enable electronic advancements in laminated glass panes. Transparent adhesives of the LOCTITE® brand are an example of optical contact bonds in adhesive applications for electronic displays, touchscreens and sensors.

[0034] Through subsequent lamination with PVB and / or bonding with an OCA (optical clear adhesive) to a second substrate, the resulting glazing becomes transparent to visible light and, according to the invention, scatters the spectral IR components of the incident light. There are little to no visible diffraction effects in the form of rainbow-colored artifacts when viewed.

[0035] A further preferred embodiment of the invention is a laminated glass pane, wherein the outer glass pane and the inner glass pane each have a thickness of 0.5 mm to 12 mm, preferably 1 mm to 10 mm, and particularly preferably 3 mm to 8 mm. These glass thicknesses are very well suited for the production of the laminated glass pane according to the invention.

[0036] The object of the invention is further achieved by a method for producing the laminated glass pane according to the invention, wherein the nanostructuring is produced by a DLIP method, the IR-reflecting layer is applied to the nanostructuring by PVD or CVD and the outer glass pane and the inner glass pane and the polymeric layer are laminated to form the laminated glass pane according to the invention.

[0037] The present invention therefore also describes a method which is based on laser-based micro- or nanostructuring by means of DLIP processes of glass substrates in conjunction with a subsequent coating of these introduced structures with an IR-reflecting layer.

[0038] The object of the invention is ultimately achieved by the use of the laminated glass pane for construction and architectural glass in the areas of residential, cultural, educational, sports, leisure, office, administrative, commercial, industrial, transportation, and special buildings. The invention is explained in more detail with reference to the following drawing and examples. The drawing shows:

[0039] Figure 1: Top view of a laminated glass pane according to the invention, Figure 2: Cross section of the laminated glass pane along the line A — A', Figure 3: Cross section through a laminated glass pane without texturing and IR-reflecting layer with incident solar rays,

[0040] Figure 4: Cross section through a laminated glass pane according to the invention with texturing and IR-reflecting layer with incident solar rays, Figure 5: Comparison of two samples,

[0041] Figure 6: Top view of the structuring on the inside of the outer pane of the laminated glass pane,

[0042] Figure 7: The representation of the periodicity and the depth of the structure Figure 8: The representation of the DLIP micro-, nano-texturing.

[0043] Figure 1 shows a plan view of a laminated glass pane I according to the invention. The laminated glass pane I according to the invention contains at least an outer glass pane 1, an inner glass pane 2 and a polymeric layer 3 between the glass pane 1 and glass pane 2. The laminated glass pane I is usually used as building glass and architectural glass.

[0044] Figure 2 shows a cross-section of the laminated glass pane I along the line A - A' from Figure 1. Shown here are the outer side 1a and the inner side 1b of the outer glass pane 1 as well as the outer side 2a and the inner side 2b of the inner glass pane 2. A polymer layer 3 is arranged between the glass pane 1 and glass pane 2. The glass panes 1, 2 have a thickness of 4 mm to 12 mm and are usually float glass. The polymer layer 3 is usually created by laminating at least one polymer film 3 between the panes 1 and 2. This is usually a PVB film (polyvinyl butyral). Thicknesses of 0.38 mm, 0.76 mm, 0.86 mm, 1.14 mm and 1.52 mm are common in construction. Instead of the PVB layer, one or more optically clear adhesives (OCA), e.g. Loctite, can be used. The inner side 1b of the outer glass pane 1 has a nanostructure 4 and an IR-reflecting layer 5 thereon.The nanostructure 4 is formed using DLIP (Direct Laser Interference Patterning). The IR-reflecting layer 5 contains Ag and is preferably embedded in a layer sequence. This layer sequence is, for example, a SiA / SiA^ layer structure, preferably the Saint-Gobain product SKN133. The IR-reflecting layer 5 is applied to the nanostructure 4 using PVD or CVD.

[0045] Figure 3 shows the cross-section through a commercially available laminated glass pane without nanostructuring and silver layer with irradiation of solar rays S. Figure 4 shows a cross-section through a laminated glass pane I according to the invention with nanostructuring 4 and silver layer 5 with irradiation of solar rays S. Figure 3 shows how the solar rays S are reflected on the outer side 1a of the outer pane 1 and on the PVB layer as rays R. Figure 4 shows how the solar rays S are scattered as rays G on the microstructured and coated surface 5 on the inner side 1b of the outer pane 1.

[0046] Figure 5 shows a diagram comparing two samples. A laminated glass pane with a MicroShade® film is used as comparison sample M. The microstructured film is applied to the inner side 1b of the outer glass pane 1 of the laminated glass pane. The integrated microstructure of the film is tailored to the angle of incidence of the sun over the course of a day and a year in terms of its energy and light transmittance. The micro-honeycombs of the film act like lamellas. The film also has an IR-reflecting coating. Comparison sample M is compared with a sample AO according to the invention. The sample AO according to the invention is a laminated glass pane I with a nanostructure 4 and an IR-reflecting layer 5 with SiA NVAg / SiA^ (SKN133 from Saint-Gobain) applied thereon. In the table below, P represents the periodicity and d the depth of the nanostructure. This is illustrated in more detail in Figure 7.The vertical axis represents the light transmittance TL (%). The horizontal axis represents the angle of incidence of the sun's rays (°). The table shows the ratio of light transmittance TL (%) at an angle of incidence of 0° to 60°, the structure in periodicity P and depth d, and any optical distortion. The inventive sample AO exhibits an improved TL 07TL 60° ratio of 0.75 compared to the known material M TL 07TL 60° of 0.51. The curve of M shows a clear decrease in TL with increasing angle of incidence. The functionality of the scattering function is demonstrated by the angular stability. The inventive sample AO exhibits improved angular stability. The inventive sample AO exhibits no optical distortion. Optical distortion is typically diffraction artifacts, such as rainbows.

[0047] The comparison with the product MicroShade® Film from MicroShade A / S shows a higher angle independence of the sample according to the invention.

[0048] Figure 6 shows a top view of the nanostructure 4 on the inner side 1b of the outer pane 1. The nanostructure 4 is uniform with a specific and defined periodicity P and depth d. P is 5 pm in the sample according to the invention. The depth d is 1.5 pm in the sample according to the invention. The ratio of P to d and the shape of the structure are clearly shown in Figure 7.

[0049] Figure 8 schematically shows DLIP micro- and nano-texturing. It shows the superposition of four coherent partial beams K of a laser. The partial beams K are combined on the workpiece in such a way that a point-like intensity profile is created in the spot through interference. The laser parameters of the nanosecond laser are:

[0050] The drawings and examples do not limit the invention in any way. List of reference symbols

[0051] I Laminated glass pane

[0052] 1 outer glass pane

[0053] 1a Outside

[0054] 1b Inside

[0055] 2 inner glass pane

[0056] 2a Outside

[0057] 2b Inside

[0058] 3 polymer layer

[0059] 4 Nanostructuring

[0060] 5 IR-reflecting layer

[0061] S incident sun rays

[0062] R reflected rays

[0063] G scattered rays

[0064] M Comparison sample MicroShade® film

[0065] K partial beams

[0066] AO inventive sample

[0067] A— A' Cross section along the line A — A'

[0068] P Periodicity (nanostructuring) d Depth (nanostructuring)

Claims

Patent claims Laminated glass pane (I) at least containing: a) an outer glass pane (1) with the outer side (1a) and the inner side (1b), b) an inner glass pane (2) with the outer side (2a) and the inner side (2b) and c) a polymer layer (3) between the glass pane (1) and the glass pane (2), wherein at least one inner side (1b) or outer side (2a) facing the polymer layer (3) has a nanostructure (4) and an IR-reflecting layer (5) thereon. Laminated glass pane (I) according to claim 1, wherein the nanostructure (4) is a laser-based micro- or nanostructuring using a DLIP process. Laminated glass pane (I) according to claim 1 or 2, wherein the IR-reflecting layer (5) contains at least two metal layers separated by oxide or nitrite-containing layers and the metal layer contains silver, gold or aluminum.Laminated glass pane (I) according to one of claims 1 to 3, wherein the metal layer has a thickness of 8 nm to 20 nm, preferably 10 nm to 17 nm. Laminated glass pane (I) according to one of claims 1 to 4, wherein the IR-reflecting coating preferably contains up to three metal layers. Laminated glass pane (I) according to one of claims 1 to 5, wherein the nanostructuring (4) has a periodicity (P) of 1 pm to 10 pm, preferably 3 pm to 7 pm and particularly preferably 4 pm to 6 pm. Laminated glass pane (I) according to one of claims 1 to 6, wherein the nanostructuring (4) has a depth (d) of 0.5 pm to 5 pm, preferably 1 pm to 3 pm and particularly preferably 1.2 pm to 1.6 pm.Laminated glass pane (I) according to one of claims 1 to 7, wherein the polymeric layer (3) contains at least one polymer, such as polyvinyl butyral (PVB), reduced-plasticizer PVB, ionoplast, ethylene vinyl acetate (EVA), polycarbonate, polymethyl methacrylate (PMMA), casting resins or transparent adhesives.

9. Laminated glass pane (I) according to one of claims 1 to 8, wherein the polymeric layer (3) has a thickness of 0.3 mm to 1.6 mm.

10. Laminated glass pane (I) according to one of claims 1 to 9, wherein the outer glass pane (1) and the inner glass pane (2) each have a thickness of 0.5 mm to 12 mm, preferably of 1 mm to 10 mm and particularly preferably of 3 mm to 8 mm.

11. A method for producing a laminated glass pane (I) according to one of claims 1 to 10, wherein the nanostructuring (4) is produced by means of a DLIP method.

12. A method for producing a laminated glass pane (I) according to one of claims 1 to 10, wherein the IR-reflecting layer (5) is applied to the nanostructure (4) by means of PVD or CVD.

13. A method for producing a laminated glass pane (I) according to one of claims 1 to 10, wherein the outer glass pane (1) and the inner glass pane (2) and the polymeric layer (3) are laminated to form a laminated glass pane (I).

14. Use of the laminated glass pane (I) according to one of claims 1 to 10, for building glass and architectural glass for the areas of living, culture, education, sport, leisure, office, administration, commerce, industry, transport and special buildings.

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