Coated pane

Abstract

The present invention relates to a coated pane comprising: a base pane comprising a first main face and a second main face, opposite said first face; a first area of the first main face of the base pane coated with a multilayer functional coating; a second area of the first main face of the base pane devoid of a multilayer functional coating; characterized in that it further comprises a transition area between the first and second areas of the first main face of the base pane, said transition area comprising subareas, having surfaces, provided with multilayer functional coating or devoid of multilayer functional coating, and to a method for its production and its use.

Description

COATED PANE

[0001] The invention relates to a coated pane comprising, on a first main face, a first area coated with a multilayer functional coating; a second area devoid of a multilayer functional coating, and a transition area between the first and second areas, as well as a method for its production and its use.

[0002] Panes with multilayer coatings are widespread both in the field of architectural glazings and in the field of motor vehicle glazings.

[0003] Exam pies of multilayer functional coatings include solar control coatings, low emissivity coatings, anti reflective coatings, infrared transmissive coating, etc.

[0004] Some of these multilayer functional coatings may include metal based layers, which may influence the transmittance, reflectance, and absorption behavior of electromagnetic radiation. In particular, the reduction of thermal radiation or the electrical heating of the glass surface are core functions of many glass coatings based on electrically conductive metals.

[0005] Electromagnetic radiation are classified in various wavelengths ranges within the electromagnetic spectrum. Examples of electromagnetic radiation in the radiofrequency range include FM, AM, UHF, VHF, or microwave radiation. Other well-known examples of electromagnetic radiation include the visible light spectrum, from 385-400 nm to 750-780 nm; or infrared radiation, commonly divided as near-infrared, mid-wavelength infrared or far infrared.

[0006] Coatings comprising at least one layer of functional layer such as silver or transparent conductive oxide, significantly reduce the transmittance of infrared thermal radiation in the space of a motor vehicle or a building situated behind the pane. In particular, in the case of motor vehicles, this property can also be combined via an electrical connection with a heating function of the functional layer coating. Such thermal control coatings are of customary use in vehicles or buildings.

[0007] Passage of specific infrared electromagnetic radiation may however be hindered by the presence of a solar control coating based on a metal layer, and, consequently, a radiation window in the form of a gap or hole may be provided in a solar control coating layer specifically to allow the passage of infrared electromagnetic radiation through that portion of the glazing.

[0008] Exam pies of such tools include lidars, standing for “light detection and ranging". It is sometimes called “laser scanning” or “3D scanning”. The technology uses laser beams to create a 3D-representation of the surveyed environment.

[0009] The term “radiation window” as used herein refers to an area of a coated pane adapted to permit near infrared radiation to pass therethrough, that is, infrared radiation within the wavelength range of from 780 to 2500 nm, or from 800 nm to 1650 nm. More specifically, known operating wavelengths of currently produced lidars are 850 nm, 905 nm, 940 nm, 1064 nm, 1310 nm, 1350nm, 1550 nm. The radiation window is thus an area of a coated pane which is provided such that infrared radiation are allowed to be emitted and / or transmitted.

[0010] Although both functions of thermal / solar control and radiation transmission are required for a same pane, the behavior of coated zones of a pane is different from uncoated zones of the same pane upon thermal treatment such as bending or tempering. This is due to the different heat absorption observed from a coated zone to an uncoated zone.

[0011] Some prior solutions include grid meshes having a distance between the lines that is significantly smaller than the wavelength of the desired electromagnetic radiation in question. To that end, the metal-containing coatings are, for example, removed in the form of lines using a suitable laser. Since only small amounts of the metal-containing coating have to be removed, the infrared radiation reflecting effect is largely retained, such as in US20160009592. However, such laser treatment process is an additional step in the production sequence, implying added cost and operation.

[0012] W02001068395A1 relates to an automotive glazing panel having an electrically heatable solar control coating layer, spaced first and second bus bars adapted to relay electrical power to the coating layer. The glazing panel is provided with at least two, spaced data transmission windows positioned at least partially in contact with the heatable solar control coating layer which are separated by a portion of the glazing panel which is in electrical contact with the electrically heatable solar control coating layer.

[0013] W02004037737A1 relates to a vehicle glazing panel having an electrically heatable radiation reflective coating layer, at least two bus bars adapted to relay electrical power to the coating layer and at least a window, in the coating layer, permeable to electromagnetic radiations, which, when submitted to a power of 1000 W / m2during 4 minutes, presents in a portion of the glazing panel delimited by the bus bars and not including the bus bars tips and their close periphery, a maximum temperature and a minimum temperature, such that the difference between the maximum temperature of the glazing panel with the window and the maximum temperature of the same glazing panel without window does not exceed 25 °C. This may be used to minimise perturbations to the heating of the glazing caused by the presence of the window permeable to electromagnetic radiations and / or provide more even heating over the entire windscreen.

[0014] US20130017344A1 relates to a method and a system is provided to form deletion windows on a glass substrate. The method includes the steps of applying a provisional masking substance of the glass substrate for masking preestablished regions of said glass substrate. The method also includes applying a reflective material on the glass substrate including the provisional masking substance. The method further includes applying heat to the glass substrate for removing the provisional masking substance of the glass substrate forming the deletion windows.

[0015] The consequence of such behavior difference in heat absorption may be responsible for poor aesthetic quality of the pane, because of optical distortions on the glass surface. In other words, where a coated region of a pane is disposed directly adjacent to an uncoated region of apane, the difference in heat absorption of the coated region compared to the uncoated region causes a notable difference in the shaping / bending behavior of the pane, leading to undesirable optical distortion where the coated region meets the uncoated region. These distortions are, apart from being unaesthetic, also problematic in view of legal regulations, such as ECE-R43, which demands compliance with threshold values in the area of the optical quality of motor vehicle window panes. Distortion may be convex or concave and render circular dots more elliptic or egg- shaped, or increase or decrease their original size.

[0016] lndeed, Regulation No. 43 of the Economic Commission for Europe of the United Nations (UN / ECE) (ECE-R43, “Uniform Provisions Concerning the Approval of Safety Glazing Materials and Their Installation on Vehicles”) defines central fields of vision for windshields of various vehicles. For vehicles of category M1 (vehicle passenger transport with at most eight seats in addition to the driver's seat), which also includes passenger cars, the field of vision A and the larger field of vision B containing it are defined. For vehicles of category M, other than M1 (other vehicles for passenger transport), and for vehicles of category N (vehicles for freight transport), a field of vision I is defined. In said central fields of vision, particularly high requirements are made for the quality of the pane, in particular in terms of its transmittance, the most distortion-free view possible, and the least possible interference with through-vision. For example, a maximum optical distortion of 2 minutes of arc in the field of vision A may be tolerated for vehicles of category M1 .

[0017] These differences in heat absorption, and the resulting optical distortion, are typically only observed after the thermal treatment, leading to production loss, which induce cost and waste. Furthermore, where the uncoated region defines a window where an optical sensor looks through the pane, the optical distortion can reduce the accuracy of the optical sensor.

[0018] There is thus still a need for coated panes capable of ensuring thermal comfort in a defined space, and allowing passage of electromagnetic radiation for communication through the pane, which may be produced at minimal cost.

[0019] The object of the present invention consists in providing a coated pane, which has, in the border region between an uncoated radiation window and the coated area of the pane, no, or at least reduced, optical distortions.

[0020] A coated pane comprising:- a base pane comprising a first main face and a second main face, opposite said first face ;- a first area of the first main face of the base pane coated with a multilayer functional coating;- a second area of the first main face of the base pane devoid of a multilayer functional coating, characterized in that it further comprises a transition area between the first and second areas of the first main face of the base pane, said transition area comprising subareas having surfaces provided with multilayer functional coating and subareas without multilayer functional coating.

[0021] It is thus particularly advantageous forthe optical distortion to be minimal in a central region (through-vision region) of the pane, when said pane is used as windshield.FIGURES

[0022] Figure 1 : illustration of a first geometrical design of the transition area of the present invention

[0023] Figure 2: illustration of a second geometrical design of the transition area of the present invention

[0024] Figure 3: illustration of a third geometrical design of the transition area of the present invention

[0025] The coated pane is intended, in a window opening, to separate an interior space from the external environment, for example the interior of a vehicle or of a building.

[0026] The base pane comprises a first main face, a second main face and an edge.

[0027] The base pane may be a glass sheet, or a plastic sheet comprising or consisting of poly(methyl meth)acrylate (PMMA), polycarbonates, polyethyleneterephthalate (PET), polyolefins, polyvinyl chloride (PVC), or mixtures thereof.

[0028] ln most instances, the base pane is a glass substrate.

[0029] The glass may be of any type, such as conventional float glass or flat glass, and may be of any composition having any optical properties, e.g., any value of visible transmission above 10%, ultraviolet transmission, infrared transmission, and / or total solar energy transmission.

[0030] The glass may thus be a glass of soda-lime-silica, aluminosilicate or borosilicate type, and the like.

[0031] The glass may be a regular clear, colored or extra-clear (i.e. lower iron content and higher transmittance) glass substrate. Further examples of glass substrates include clear, green, bronze, or blue-green glass substrates.

[0032] ln preferred embodiments, the glass may be an “infrared transmissive glass”, characterized by an absorption coefficient lower than 25 nr1in the wavelength range from 750 to 1650 nm. To quantify the low absorption of the first glass sheet in the infrared range, in the present description, the absorption coefficient is used in the wavelength range from 750 to 1650 nm.

[0033] The infrared wavelength typically ranges of from 780 nm to more than 10 micrometers. However, the use of infrared technologies is typically processed at wavelengths in the nearinfrared, that is, that range of the wavelength nearest to the visible wavelength, border to the red, namely ranging of from 780-2500 nm.

[0034] ln the scope of the present invention, the terms “infrared rays”, “infrared light” and “infrared wavelengths” may be used interchangeably and encompass the same wavelength region ranging of from 780-2500 nm.

[0035] The absorption coefficient is defined by the ratio between the absorbance and the optical path length traversed by electromagnetic radiation in a given environment. It is expressed in nr1. It is independent of the thickness of the material but it is function of the wavelength of the absorbed radiation and the chemical nature of the material.

[0036] The absorption coefficient ( ) at a chosen wavelength A can be calculated from a measurement in transmission (T) as well as the refractive index n of the material (thick = thickness), the values of n, p and T being a function of the chosen wavelength A:with p = (n-1)2 / (n+1)2.

[0037] The glass may preferably have an absorption coefficient < 25 nr1, in the wavelength range of 750-1650 nm, alternatively < 15 nr1, alternatively < 10 nr1, alternatively < 5 nr1.

[0038] A preferred glass may further be characterized by a transmittance for infrared rays TIR > 90% and / or a visible light transmittance Tvis > 88% , and / or a Tvis / TIR > 0.70, or > 0.90, for a glass sheet of 4 mm thickness (with TIR considered in the wavelengths of 780-2500 nm, and Tvis considered in the wavelengths of 380 - 780 nm).

[0039] Conventional “clear glass” typically has an absorption coefficient about 30 nr1order, significantly higher than the preferred glass.

[0040] Different compositions of glass may be suitable in the scope of the present invention, such as soda-lime-silica glass, alumino-silicate, boro-silicate, provided the absorption < 25 nr1, in the wavelength range from 750 to 1650 nm.

[0041] The base glass composition may comprise a total content expressed in weight percentages of glass:SiO255 - 85%AI2O30 - 30%B2O3 0 - 20%Na2O 0 - 25%CaO 0 - 20%MgO 0 - 15%K2O 0 - 20%BaO 0 - 20%.

[0042] Alternatively, the base glass composition may comprise a total content expressed in weight percentages of glass:SiO255 - 78%AI2O3 0 - 18%B2O3 0 - 18%Na2O 0 - 20%CaO 0 - 15%MgO 0 - 10%K2O 0 - 10%BaO 0 - 5%.

[0043] Alternati vely , the base glass composition may comprise a total content expressed in weight percentages of glass:SiO260 - 75%AI2O30 - 6%B2O3 0 - 4%CaO 0 - 15%MgO 0 - 10%Na2O 5 - 20%K2O 0 - 10%BaO 0 - 5%.

[0044] ln addition to its basic composition, the glass may include other components according to the desired effect. In the scope of the present invention, a very transparent glass in the high infrared (IR), with weak or no impact on its aesthetic or its color, may be obtained by combining a low iron quantity and chromium in a range of specific contents in the glass composition.

[0045] The glass sheet composition may thus comprise a content, expressed as the total weight of glass percentages, of- Fe total (expressed as Fe2O3) in amounts of 0,002 to 0,06% and O2O3 in amounts of 0,0001 to 0,06 %; or- Fe total (expressed as Fe2O3) in amounts of 0,002 to 0,06% and O2O3 in amounts of 0,0015 to 1 % and Co in amounts of 0,0001 to 1%; or- Fe total (expressed as Fe2O3) in amounts of 0,02 to 1 % and Cr2Os in amounts of 0,002 to 0,5 % and Co in amounts of 0,0001 to 0,5%; or- Fe total (expressed as Fe2O3) in amounts of 0,002 to 1 % and Cr2Os in amounts of 0,001 to 0,5 % and Co in amounts of 0,0001 to 0,5 % and Se in amounts of 0,0003 to 0,5 %; or- Fe total (expressed as Fe2O3) in amounts of 0,002 to 0,06% and CeO2in amounts of 0,001 to 1 %; or- Fe total (expressed as Fe2O3) in amounts of 0,002 - 0,06% ; and one of the following components:- manganese (calculated as MnO) in an amount ranging from 0.01 to 1 % by weight;- antimony (expressed as Sb2C>3), in an amount ranging from 0.01 to 1 % by weight;- arsenic (expressed as AS2O3), in an amount ranging from 0.01 to 1 % by weight, or- copper (expressed as CuO), in an amount ranging from 0.0002 to 0.1 % by weight.

[0046] These types of glass having high transmission in the infrared are well known by the skilled person and need not be further described herein. Alternatives may exist, which may be suitable in the scope of the present invention, provided the absorption coefficient is < 25 nr1, as discussed above.

[0047] The glass may be annealed, tempered or heat strengthened glass.

[0048] The base pane may have a thickness ranging from 0.5 mm to 15 mm, alternatively from 0.5 mm to 10 mm, alternatively from 0.5 mm to 8 mm, alternatively from 0.5 mm to 6 mm.

[0049] The first main face of the base pane comprises- a first area coated with a multilayer functional coating; and- a second area devoid of a multilayer functional coating.

[0050] The first area and the second area each have an edge, setting the border between the first area and the second area respectively.

[0051] ln the scope of the present invention, the multilayer functional coating may be selected from any coating which exhibits a different thermal behavior as compared to neat uncoated glass, upon thermal treatment. Said thermal treatment involves heating the glass substrate to a temperature > 350°C, alternatively > 450°C.

[0052] Examples of such multilayer functional coating include an infrared reflective coating based on at least one metallic functional layer; an infrared reflective coating based on at least one transparent conductive oxide functional layer; an infrared antireflective coating, among others.

[0053] When discussing coatings in the present invention, it is meant coatings comprising one or more layers of metal, metal oxides, metal nitrides, metal oxynitrides, metal carbides, or mixtures thereof. In the scope of the present invention, such coatings may typically be obtained by physical vapor depositions or chemical vapor deposition methods. Such coatings may have a thickness ranging of from 5 to 1000 nm.

[0054] In the coatings discussed herein, it is typically understood that the layers are numbered in sequence starting from the substrate surface. That is, a first layer is understood to be the first applied on the substrate, a second being the second layer applied on the substrate, above the first layer. The successive order of the positions is considered relative to the substrate onwards, up to the uppermost layer.

[0055] ln the scope of the present invention, the terms “below”, “underneath”, “under” indicate the relative position of a layer vis a vis a next layer, within the layer sequence starting from the substrate. In the scope of the present invention, the terms “above”, “upper” indicate the relative position of a layer vis a vis a next layer, within the layer sequence starting from the substrate.

[0056] ln the scope of the present invention, the relative positions of the layers within the stack do not necessarily imply direct contact between the layers. That is, some interlayer may be provided between the first and second layer. For example, a first layer "deposited over" the substrate does not preclude the presence of one or more other coating layers of the same or different composition located between that first layer film and the substrate, provided the objective of the present invention is not jeopardized.

[0057] ln some instances, a layer may actually be composed of several multiple individual layers. When a layer is qualified as low refractive index layer, it may comprise sublayers each having a low refractive index. When a layer is qualified as high refractive index layer, it may comprise sublayers each having a high refractive index.

[0058] ln the scope of the present invention, a high refractive index material has a refractive index > 1.8 alternatively > 1 .9, alternatively > 2.0, at a wavelength of 550 nm.

[0059] ln the scope of the present invention, a low refractive index material has a refractive index < 1 .7, alternatively < 1.6, at a wavelength of 550 nm.

[0060] The refractive index at a wavelength of 550 nm of the high refractive index materials is higher than the refractive index of the low refractive index materials.

[0061] Unless stated otherwise, all layer thicknesses herein are geometrical layer thicknesses.

[0062] ln a first embodiment, the multilayer functional coating is an infrared reflective coating based on at least one metallic functional layer.

[0063] The first area (FA) of the base pane may thus be provided with an infrared reflective coating mainly to ensure solar control and reduce the heat transfer towards the interior of the vehicle or building.

[0064] The present infrared reflective coating may comprise n metallic infrared reflective layers and n + 1 dielectric layers, with n > 1 , such that each metallic infrared reflective layer is surrounded by two dielectric layers.

[0065] The metallic infrared reflective layer may be made of silver, gold, palladium, platinum or alloys thereof. Preferred infrared reflective layers comprise silver or silver alloys, for production convenience and cost management.

[0066] The metallic infrared reflective layer or functional layer may have a thickness from 2 to 30 nm, alternatively from 5 to 20 nm, alternatively from 7 to 18 nm. These thickness ranges may enable the desired solar control function and / or conductivity (when needed) to be achieved.

[0067] The dielectric layers may typically comprise oxides, nitrides, oxynitrides or oxycarbides of Zn, Sn, Ti, Zr, Si, In, Al, Bi, Ta, Hf, Mg, Nb, Y, Ga, Sb, Mg, Cu, Ni, Cr, Fe, V, B or mixtures thereof.

[0068] ln certain embodiments of the present invention, the dielectric layers may comprise oxides, nitrides, oxynitrides or oxycarbides of Zn, Sn, Ti, Zr, Si, In, Al, Nb, Sb, Ni, Cr, V, Mb, Mg or mixtures thereof. Alternatively, the dielectric layers may comprise oxides, nitrides, oxynitrides of Zn, Sn, Ti, Zr, Si, In, Al, Nb, Sb, Ni, Cr, or mixtures thereof.

[0069] These materials may optionally be doped, where examples of dopants include aluminum, zirconium, or mixtures thereof. The dopant or mixture of dopants may be present in an amount up to 15 wt %.

[0070] Typical examples of dielectric materials include, but are not limited to, silicon based oxides, silicon based nitrides, zinc oxides, aluminum doped zinc oxides, zinc-based oxides, tin oxides, mixed zinc-tin oxides, silicon nitrides, silicon oxynitrides, titanium oxides, aluminum oxides, zirconium oxides, niobium oxides, aluminum nitrides, bismuth oxides, mixed silicon-zirconium nitrides, and mixtures of at least two thereof, such as for example titanium-zirconium oxides, titanium-niobium oxides, zinc-titanium oxides, zinc-gallium oxides, zinc-indium-gallium oxides, zinc-titanium-aluminum oxides, zinc-tin-titanium oxides, zinc-aluminum-vanadium oxides, zinc-aluminum-molybdenum oxides, zinc-aluminum-magnesium oxides, zinc-aluminum-chromium oxides, zinc-aluminum-copper oxides, zinc-titanium-zirconium oxides.

[0071] The dielectric layer may consist of a plurality of individual layers comprising or essentially consisting of the above materials.

[0072] The dielectric layers may each have a thickness ranging from 0.1 to 300 nm, alternatively from 0.1 to 200 nm, alternatively from 1 to 150 nm, alternatively from 1 to 110 nm. Different dielectric layers may have different thicknesses. That is, the first dielectric layer may have a thickness that is the same or different, greater or smaller, compared to the thickness of the second or third or any other dielectric layer.

[0073] Typically, a pane of clear float glass (soda-lime glass) provided with such an infrared reflective coating may have a light transmittance of 25 to 80%, provided the solar control is ensured for thermal comfort within the inner environment.

[0074] The infrared reflective coating may be an electrically conductive coating such as an electrically conductive heated window coating or a single-film or multi-film coating capable of functioning as an antenna.

[0075] Such infrared reflective coatings are well known to the skilled person and need not be further detailed herein.

[0076] The infrared reflective coating is applied on a first area of the first main face of the base pane, typically by physical vapor deposition methods.

[0077] ln a second embodiment, the multilayer functional coating is an infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer.

[0078] Here too, the first area (FA) of the base pane may be provided with an infrared reflective coating to ensure solar control and reduce the heat transfer towards the interior of the vehicle or building.

[0079] The infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer comprises at least one functional layer that contains a transparent conductive oxide (TCO), selected from indium tin oxide, antimony-doped or fluorine-doped tin oxide, gallium- and / or aluminum-doped zinc oxide, mixed indium zinc, vanadium oxide, tungsten and / or magnesium doped vanadium oxide, niobium-doped titanium oxide, and / or cadmium stannate; or at least one nitride based functional layer with low emissivity properties selected from titanium nitride, chromium nitride, niobium nitride, molybdenum nitride, hafnium nitride, or mixtures thereof.

[0080] Preferred transparent conductive oxide (TCO) may be selected from indium tin oxide, antimony-doped or fluorine-doped tin oxide and / or aluminum-doped zinc oxide (ZnO:AI) and / or gallium-doped zinc oxide (ZnO:Ga), with indium tin oxide or fluorine-doped tin oxide most preferred.

[0081] Preferred nitride based functional layer may be selected from titanium nitride or chromium nitride, or mixtures thereof.

[0082] The refractive index of the material of the TCO functional layer is preferably 1.7 to 2.5.

[0083] The thickness of the at least one functional layer may range of from 45 nm to 210 nm, preferably 90 nm to 175 nm, and most preferably 105 nm to 170 nm. This range allows for an optimal compromise between a low emissivity and thermal treatment resistance of the pane. In the scope of the present invention, the low emissivity coating may be characterized by an emissivity < 0.2 (according to the standard EN 12898).

[0084] A first suitable infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer includes a coating comprising the following layers, in sequence: a first low refractive index layer, for example silicon oxide, and a transparent conductive oxide layer.

[0085] ln a second suitable infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer, the at least one TCO functional layer may be surrounded by dielectric layers which may have alternating low and high refractive indices. In particular, the first dielectric layer, that is, the layer under the TCO functional layer, may comprise a first sublayer of high refractive index material, and subsequently, a second sublayer of low refractive index material. The second dielectric layer, that is, the layer above the TCO functional layer, may comprise a third sublayer of high refractive index material, and subsequently, a fourth sublayer of low refractive index material.

[0086] Exam pies of high refractive index dielectric layers for the second embodiment, include zirconium doped titanium dioxide, silicon doped titanium dioxide, mixed oxide of zinc and tin, mixed oxide of titanium and silicon.

[0087] Examples of low refractive index dielectric layers for the second embodiment, include silicon oxide, zirconium doped silicon oxide, mixed oxide of silicon and aluminum, magnesium fluoride.

[0088] An optimal infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer includes a coating comprising the following layers, in sequence: a first high refractive index layer, a first low refractive index layer, a transparent conductive oxide layer, an optional barrier layer, a second low refractive index layer, and an optional top coat having a low refractive index.

[0089] The first high refractive index layer may have a thickness ranging of from 7 to 23 nm, alternatively of from 8 to 20 nm, alternatively of from 9 to 19 nm.

[0090] The first low refractive index layer may have a thickness ranging of from 18 to 55 nm, alternatively of from 20 to 50 nm, alternatively of from 25 to 45 nm.

[0091] The transparent conductive oxide layer may have a thickness ranging of from 75 to 210 nm, alternatively of from 90 to 175 nm, alternatively of from 105 to 170 nm.

[0092] The optional barrier layer may have a thickness ranging of from 0 to 15 nm, alternatively of from 1 to 15 nm, alternatively of from 1 to 12 nm.

[0093] The second low refractive index layer may have a thickness ranging of from 40 to 110 nm, alternatively of from 45 to 105 nm, alternatively of from 50 to 95 nm.

[0094] The optional top coat may have a thickness ranging of from 2 to 40 nm, alternatively of from 5 to 35 nm, alternatively of from 6 to 30 nm.

[0095] The optional topcoat may be a layer of silicon oxide comprising zirconium in an amount of 5 to 40 mol% and / or 0.2 to 3.0 at%. Such an uppermost layer allows for tuning the neutral color rendering of the low emissivity coating together with superior durability, for example against scratches.

[0096] An optimal infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer may thus include a coating comprising the following layers, in sequence: a first high refractive index layer having a thickness ranging of from 7 to 23 nm, a first low refractive index layer having a thickness ranging of from 18 to 55 nm, a transparent conductive oxide layer having a thickness ranging of from 75 to 210 nm, an optional barrier layer having a thickness ranging of from 0 to 15 nm, a second low refractive index layer having a thickness ranging of from 40 to 110 nm, and an optional top coat having a low refractive index having a thickness ranging of from 2 to 40 nm.

[0097] Typically, a pane of clear float glass (soda-lime glass) provided with such an optimal infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer may have a light transmittance of 85 to 94%.

[0098] The present infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer may be characterized by an emissivity < 0.35, preferably < 0.25 (according to the standard EN 12898).

[0099] The infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer may be applied on a first area of the first main face of the base pane, typically by physical vapor deposition methods, or chemical vapor deposition (CVD, PECVD, etc.).

[0100] ln a third embodiment, the multilayer functional coating is an infrared antireflective coating.

[0101] The first area (FA) of the base pane may be thus be provided with an infrared antireflective coating to maximize infrared rays transmission through the coated pane and to reduce energy loss of near infrared light, for example from a laser or near infrared camera.

[0102] Such an anti-reflective coating for infrared radiation, in particular near-infrared light in the range between 800 and 2000 nm, may be provided for infrared rays in operating wavelengths of 850 nm, 905 nm, 940 nm, 1064 nm, 1310 nm, 1350 nm, 1550 nm, 1650 nm. These operating wavelengths will depend on the optical assembly making use of said infrared antireflective coating.

[0103] ln a LIDAR for automotive applications, for example, operating wavelengths may be of 905 nm, or 1550 nm, among others. An acceptable variance of 25 nm around the nominal value of the wavelength may be considered, such that, for example, a wavelength range of 1525 to 1575 nm may be accepted around the nominal value of 1550 nm

[0104] The infrared antireflective coating may comprises S sequence(s) of thin layers, wherein a sequence comprises a layer of high refractive index material underneath a layer of low refractive index material. In order to ensure the optical path is optimized, it may be recommended to ensurecontact between said high refractive index material underneath said layer of low refractive index material within a sequence. The sequences are then stacked upon one another, such that the coating comprises an alternation of layers of high and low refractive indices. In view of further optimizing the optical path, the sequences may also be in contact with one another. Each layer typically has a geometrical thickness < 900 nm, alternatively < 800 nm, alternatively < 700 nm.

[0105] The infrared antireflective coating thus comprises 1 to 4 or more sequences of thin layers of alternating refractive indices, wherein each layer may comprise one or more sublayer.

[0106] Examples with 2 sequences of alternating refractive indices may comprise a first layer of high refractive index layer of 10 to 70 nm; a second layer of low refractive index layer of 20 to 80 nm; a third layer of high refractive index layer of 140 to 240 nm; a fourth layer of low refractive index layer of 140 to 300 nm.

[0107] Examples with 4 sequences of alternating refractive indices may comprise a first layer of high refractive index layer of 8 to 18 nm; a second layer of low refractive index layer of 40 to 80 nm; a third layer of high refractive index layer of 20 to 50 nm; a fourth layer of low refractive index layer of 20 to 50 nm; a fifth layer of high refractive index layer of 20 to 60 nm; a sixth layer of low refractive index layer of 25 to 65 nm; a seventh layer of high refractive index layer of 8 to 30 nm; an eighth layer of low refractive index layer of 100 to 400 nm.

[0108] Examples of layers with high refractive index for the third embodiment, may be independently selected from:- an oxide of Zr, Nb, Sn, Zn or Ti;- a mixed oxide of two or more of Ti, Zr, Nb, Si, Sb, Sn, Zn, In;- a nitride of Si, Zr, Al, B;- a mixed nitride of two or more of Si, Zr, Al, B.

[0109] Examples of layers with low refractive index for the third embodiment, may be independently selected from silicon oxide, silicon oxynitride, silicon oxycarbide, aluminum oxide, mixed silicon aluminum oxide, mixed silicon zirconium oxide, aluminium doped silicon oxide, boron doped silicon oxide, magnesium fluoride, magnesium oxide, aluminum fluoride, yttrium fluoride, or mixtures thereof.

[0110] Examples of a sequence of an infrared antireflective coatings include coating comprising a first layer of high refractive index material such as titanium zirconium oxide, or niobium oxide, or silicon nitride, and a first layer of low refractive index material such as silicon oxide, or aluminium oxide, or magnesium fluoride. This sequence may be repeated more than once, with similar materials.

[0111] I n some instances, the uppermost layer (that is, the last layer of the coating moving away from the substrate) having a low refractive index of the antireflective coating may comprise at least one sublayer of mixed silicon zirconium oxide. The sublayer of mixed silicon zirconium oxide may comprise 5 to 50 mol% of zirconium oxide, preferably 8 to 20 mol%. Such sublayer of mixed silicon zirconium oxide may have a refractive index < 1.7 at 550 nm, alternatively of from 1.55 to1.65. When such mixed silicon zirconium oxide is present in the uppermost layer of low refractive index, superior durability is imparted to the antireflective coating.

[0112] The deposition methods of the different layers of the infrared transmissive coating based on alternation of dielectric layers of high and low refractive indices include chemical vapor deposition (CVD), Plasma enhanced chemical vapor deposition (PECVD), Physical vapor deposition (PVD), magnetron sputtering, wet coating, etc. Different layers may be deposited using different techniques.

[0113] l n embodiments compatible with the above, the second area (SA) of the first main face of the base pane is devoid of a multilayer functional coating such as provided on the first area.

[0114] The transition area (TA) is situated between the first area (FA) and the second area (SA) of the first main face of the base pane, said transition area comprising subareas having surfaces provided with multilayer functional coating and subareas without multilayer functional coating, that is, free of multilayer functional coating.

[0115] The transition area extends from the edge of the first area to the edge of the second area. In absence of the transition area, the first and second area have the same edge defining one area from the other by a sharp line. That is, in the scope of the present invention, the transition area serves as a border to the junction of the first and second areas of the first surface of the base pane by its subareas having surfaces provided with multilayer functional coating and subareas without multilayer functional coating.

[0116] lnstead of having a sharp line definition, the transition area is rather set out as a fading out between the first area into the second area, such that the surface coverage by the multilayer functional coating is transitionally or gradiently reduced rather than being abruptly discontinued.

[0117] The transition area is thus a surface of the first main surface of the base pane coated with gradually less multilayer functional coating than the first area - coated subareas, moving away into the second area devoid of multilayer functional coating - uncoated subareas.

[0118] The role of the present transition area is to allow a smooth transition from the area provided with multilayer functional coating and the area devoid of it, such that optical distortion upon thermal treatment is reduced or eliminated. In other words, the presence (e.g., the thickness and / or the density) of the multilayer functional coating decreases within the transition area (TA) as the transition area extends from the first area (FA) to the second area (SA), the heat absorption of the multilayer functional coating during thermal treatment also decreases within the transition area (TA) as the transition area extends from the first area (FA) to the second area (SA), thereby reducing optical distortion within the second area (SA).

[0119] The transition area advantageously minimizes the visual conspicuousness of a coated and an uncoated area of a coated pane, for example when said pane is used as a windshield.

[0120] The subareas of the transition area may form a geometrical design, or transition design, which fades out from the coated zone (FA) to the non-coated zone (SA). Starting at the edge of the coated zone, the subareas of the transition area form a geometrical design which is coatedon the glass, fading out to the non-coated subareas. The geometrical design of the transition area and subareas is obtained by pattern-coating, discussed below.

[0121] The geometrical design is not limited per se, and may include a wide variety of patterns. Some non-exhaustive examples of said patterns include discrete circles, dots, triangles, squares, rectangles, pentagons, hexagons, octagons, ovals, waves, straight or curved lines, jigsaws, shapes, letters, logos, etc., depending on the overall desired effect.

[0122] The size and distribution of the patterned shapes may be varied to produce the gradient in coating on the surface of the transition area. The distribution of the shapes may be closely spaced, or sparse spacing, or adjacent shapes, of varying size and / or spatial distribution.

[0123] Figures 1 , 2 and 3 feature potential geometrical designs which may be envisaged in the scope of the present invention: 1 : faded squares, 2: faded lines, 3: faded circles. Sizes and designs may vary upon requirements.

[0124] Care must however be taken that the geometrical design does not negatively impact the field of view of the driver (regulatory constraints) or building occupant, compromising with the aesthetics as observed from the outside perspective.

[0125] This coating gradient by geometrical design allows for a smooth transition between the first and second areas - coated and un-coated, such that the temperature behavior upon bending does not cause optical distortion.

[0126] The transition area has a width ranging of from 1 to 45 mm, preferably from 3 to 40 mm, more preferably from 5 to 35 mm, more preferably from 6 to 25 mm, even more preferably from 7 to 20 mm, still more preferably from 8 to 16 mm. A larger width may have the advantage of smoothing out more the transition between the two first and second areas, while a thinner width may have the advantage of a reduced visible effect. The optimal width may thus be selected upon compromising the expectations and effects such that optical distortion is reduced and aesthetic impact is negligible.

[0127] The transition area, in addition to the advantage of reduction of the optical distortion and thus wasted products, also has the advantage that it is easily put in place at the production stage during the coating step of the base pane, and thus does not add on production cost.

[0128] The present invention also provides for a laminated glazing comprising the coated pane described above.

[0129] The present invention thus also relates to a laminated pane comprising1)the base pane according to the above,2)a thermoplastic material,3)a second pane comprising a first main face and a second main face, opposite said first face, where the thermoplastic material bonds the two panes together by adhering a main face of the base pane to a main face of the second pane.

[0130] The laminated pane of the present invention is also intended, in a window opening, to separate an interior space from the external environment, for example the interior of a vehicle or of a building.

[0131] The surfaces of a laminated pane are typically referenced as follows. The most external surface of the first pane in contact with the exterior environment is referred to as side 1. The opposite surface of that first pane is referred to as side 2. The most internal surface of the second pane in contact with the interior environment is referred to as side 4. The opposite surface of that second pane is referred to as side 3. The surfaces 2 and 3 face one another and are bonded to one another by means of the thermoplastic interlayer.

[0132] The second pane herein may independently be a glass sheet, or a plastic sheet comprising or consisting of poly(methyl meth)acrylate (PMMA), polycarbonates, polyethyleneterephthalate (PET), polyolefins, polyvinyl chloride (PVC), or mixtures thereof.

[0133] ln most instances, the second pane and the base pane will both be glass substrates, independently chosen from the glass types discussed above, and preferably float glass.

[0134] Preferably, at least one of the second pane or the base pane will be an “infrared transmissive glass”, characterized by an absorption coefficient lower than 25 nr1in the wavelength range from 750 to 1650 nm, such as discussed above.

[0135] More preferably, the second pane and the base pane will both be “infrared transmissive glass”, characterized by an absorption coefficient lower than 25 nr1in the wavelength range from 750 to 1650 nm.

[0136] The second pane may have a thickness ranging from 0.5 mm to 15 mm, alternatively from 0.5 mm to 10 mm, alternatively from 0.5 mm to 8 mm, alternatively from 0.5 mm to 6 mm.

[0137] Both the second pane and base pane may have a thickness ranging from 0.5 to 4 mm.

[0138] Both panes may have the same thickness, for example 0.5 mm, or 0.8 mm, or 1.2 mm, or 1.6 mm, or 2.1 mm, or 3 mm. Such symmetrical construction in glass thickness allows for ease of process and conventional sizing of the laminating process.

[0139] Both panes may also have different thicknesses, providing for asymmetrical laminated glazings, for example pane 1 = 0.5 mm and pane 2 = 2.1 mm, or pane 1 = 0.8 mm and pane 2 = 2.1 mm, or pane 1 = 0.5 mm and pane 2 = 1.6 mm, pane 1 = 0.8 mm and pane 2 = 1.6 mm, or pane 1 = 1.6 mm and pane 2 = 2.1 mm. Such asymmetrical constructions in glass thickness allow for flexibility in curvature, and / or in weight management and / or flexibility in light / solar modulation.

[0140] The thermoplastic interlayer of the present laminated pane (also referred to as "polymer interlayer sheet," "thermoplastic interlayer," “interlayer”) may designate a single-layer sheet or a multilayered interlayer. A "single-layer sheet," as the name implies, is a single or monolithic thermoplastic layer extruded as one layer which is then used to laminate two panes. A multilayered interlayer, on the other hand, may comprise multiple layers, including separately extruded layers, co-extruded layers, or any combination of separately and co-extruded layers of thermoplastic material. Thus a multilayered interlayer could comprise, for example: two or moresingle-layer sheets combined together ("plural-layer sheet"); two or more layers co-extruded together ("co-extruded sheet"); two or more co-extruded sheets combined together; a combination of at least one single-layer sheet and at least one co- extruded sheet; a combination of at least one plural-layer sheet and at least one co-extruded sheet, or any other combination of sheets as desired.

[0141] Typical materials for the thermoplastic interlayer include, but are not limited to, polyvinyl acetal, polyvinyl butyral, polyurethane, poly(ethylene-co-vinyl acetate), polyvinylchloride, poly(vinylchloride-co-methacrylate), polyethylenes, polyolefins, ethylene acrylate ester copolymers, poly(ethylene- co-butyl acrylate), silicone elastomers, epoxy resins, and acid copolymers.

[0142] The thermoplastic films preferably contain polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (Pll) and / or mixtures thereof and / or copolymers thereof, particularly preferably polyvinyl butyral.

[0143] The films are preferably based on the materials mentioned but can, however, contain other components, for example, plasticizers, photophores, heat insulating particles, infrared absorbing particles, polymer-dispersed liquid crystals, suspended particles, pigments, colorants, or UV absorbers, preferably with a content of less than 50%.

[0144] The individual thermoplastic film layer preferably have a thickness of about 0.2 mm to 1 mm, for example, 0.38 mm or 0.76 mm.

[0145] ln the first embodiment, when the multilayer functional coating is an infrared reflective coating based on at least one metallic functional layer, the thermoplastic interlayer is indicated to join the first main face of the base pane comprising the infrared reflective coating. Typically, such infrared reflective coating is preferably in contact with the thermoplastic interlayer, and may here be irrespectively positioned in the second or third position in the laminated glazing.

[0146] ln the second and third embodiments, when the multilayer functional coating is an infrared reflective coating based on at least one transparent conductive oxide (TCO) functional layer, or an infrared antireflective coating, the thermoplastic interlayer is indicated to join the second main face of the base pane opposite the multilayer functional coating. Typically, such multilayer functional coating does not require to be in contact with the thermoplastic interlayer, and may here be irrespectively positioned in the first or fourth position in the laminated glazing.

[0147] ln some instances, alone or compatible with the above, the present laminated pane may thus further comprise a performance film selected from low emissivity coatings (comprising transparent conductive oxides or nitrides functional layers), HUD reflective films or coatings, or a further solar control film on a PET substrate, or the like.

[0148] The present coated pane may be obtained by the following method, comprising, in sequence, the steps of :1) providing for a base pane comprising a first main face and a second main face, opposite said first face,2) providing for a masking coating on at least a second area of the first main face of the base pane, said masking coating comprising a geometrical design to transition from the at least second area of the first main face (masked area) to a first area of the first surface (unmasked area),3) providing for a multilayer functional coating over at least part of the first main face of the base pane which is covered by the masking coating and over at least part of the first main face of the base pane which is free of the masking coating,4) removing the masking coating which is covered by the multilayer functional coating, from the base pane,5) subjecting the base pane to a thermal treatment.

[0149] The provision of the masking coating is not limited per se, and various techniques are known to the skilled person, including various materials such as solid particles, pastes or paints.

[0150] l n a non-limiting example of such a method, the masking coating may comprise inert solid particles, that are preferably inorganic or substantially inorganic, preferably having low solubility in water. The solid particles may be insoluble or substantially insoluble in water. For example, the inert solid may be an alkaline-earth carbonate, preferably calcium carbonate. Calcium carbonate has the advantage to be a readily available and cheap compound.

[0151] The masking coating may be an enamel, comprising a frit, a medium and perhaps pigments for the colour. Enamels may be applied easily onto the main face of the pane, for example by screen-printing techniques, and may provide the portion of the pane free of the coating film with a substantially well-defined pattern, including the pattern of the geometrical design of the transition area.

[0152] Advantageously, the enamel is colourless or transparent, such that any traces of such an enamel that may inadvertently be present on the finished product may be substantially invisible to the naked eye.

[0153] Once the masking coating has been applied over the base pane, it is preferably dried. The drying may occur at room temperature with or without pulsed air or by heating the substrate with hot pulsed air or with infra-red lamps or in a heating oven, or by a combination of at least two of these variations.

[0154] The step of provision of the multilayer functional coating may include a method selected among physical vapor deposition (sputtering) process (PVD), or chemical vapor deposition (CVD), or plasma enhanced chemical vapor deposition (PECVD), or the like. Different layers of the respective coatings may be deposited using different techniques.

[0155] The removal of the masking coating may be carried out using different techniques, such as rinsing, washing, brushing, heating or the like.

[0156] In a non-limiting example of such a method, the removal of the masking coating may be carried out using a liquid and preferably water, preferably at least 50% of water, more preferably 80% of water and most preferably consists of water. Application of the fluid to remove the maskingcoating may occur by any means, for example, spraying or pouring water, water vapour or steam and is preferably applied at a pressure greater than atmospheric pressure, for example by using pressurised jet of water. The fluid may be applied at room temperature or may be heated.

[0157] Application of water or other fluid to remove the masking coating may help to avoid possible damages to the remaining coating film that could occur when using other techniques such as rubbing, brushing and / or any other related means.

[0158] The thermal treatment comprises heating the glazing to a temperature of at least 560°C in air, for example between 560°C and 700°C, in particular around 630°C to 670°C, during around 3, 4, 6, 8, 10, 12 or even 15 minutes according to the heat-treatment type and the thickness of the glazing. The treatment may comprise a rapid cooling step after the heating step, to introduce a stress difference between the surfaces and the core of the glass so that in case of impact, the so-called tempered glass sheet will break safely in small pieces. If the cooling step is less strong, the glass will then simply be heat-strengthened and in any case offer a better mechanical resistance.

[0159] The pane so produced will thus be provided with a multilayer functional coating on a first area and no coating on a second area, with the multilayer functional coating in the transition area fading out from the edge of the first area to the second area.

[0160] An optional step may be to remove (de-coat) the multilayer functional coating from the transition area by known means.

[0161] Examples of removal techniques include mechanical removal techniques such as grinding, sandblasting, brushing; gas burning; laser radiation removal technique.

[0162] ln some instances, compatible with the above, for aesthetics purposes, the removal of the multilayer functional coating may be required. In such instances, the transition area will no longer comprise multilayer functional coating, but the transition area will however remain free of optical distortion.

[0163] ln the instances where the coated pane is included in a laminated pane, the step of assembling the 2 panes and the at least one interlayer may be a lamination step for flat panes, or may be a bending step for curved laminated panes, which bending step includes the steps of first bending the panes and secondly, laminating said bent panes.

[0164] ln the instances of a performance film is present in the laminated pane, the step of positioning said film is included in the above method according to the requirements and precautions of said film, as known in the art.

[0165] The laminated pane may then be subject to enamel deposition or preparation for inclusion within a frame.

[0166] The present invention also relates to the use of the coated pane according to the invention as a window pane in architectural or transport applications.

[0167] Transport applications include vehicles useful for transportation on road, in air, in and on water, in particular cars, busses, tramways, trains, ships, aircraft, spacecraft, space stations and other motor vehicles.

[0168] Preferred window panes include vehicle windows such as windshields.

[0169] Architectural applications include displays, windows, doors, partitions, shower panels, and the like.

[0170] The present invention last relates to the use of a transition area between a first area coated with a multilayer functional coating and a second area devoid of said multilayer functional coating on a first main face of a base pane, said transition area comprising subareas, having surfaces, provided with multilayer functional coating or devoid of multilayer functional coating, to reduce optical distortion upon thermal treatment of said base pane.

[0171] The optical distortion is preferably assessed using the method according to ASTM C1652, wherein the reflected image of processed glass is photographed and the photographic image analyzed to quantify the distortion due to surface waviness. The test method is also useful to quantify optical distortion observed in transmitted light in laminated glass assemblies. The results are provided in millidiopters.

[0172] The optical distortion according to ECE-R43 requirements is measured in order to ensure the glazing is not probe to confuse the driver. Here, a projection of a raster, for example circular shapes, is provided and changes in the projected image are measured in presence and absence of the glazing. The results are provided in minutes of arc.

[0173] Several other methods exist, all relying on various measurements and conditions.

[0174] The transition area is, as discussed above, set out as a fading out between the first area into the second area, such that the surface coverage by the multilayer functional coating is transitionally or gradiently reduced rather than being abruptly discontinued. The smooth transition from the area provided with multilayer functional coating and the area devoid of it, as effected by the transition area as provided herein allows for a reduction (or elimination) of optical distortion upon thermal treatment of the base pane. The reduction of the distortion, as measured according to ASTM C1652 method may be of at least 5%, as compared to a pane without a specific transition area.

[0175] The transition area is particularly useful when the multilayer functional coating is an infrared reflective coating based on at least one metallic functional layer. In such instances, according to the first embodiment discussed above, the transition area allows for a smooth transition of the first area provided with the infrared reflective coating to the second area devoid of said coating, where the second area is the radiation window. The solar control is effectively maintained and the radiation window is not negatively perceived on the overall surface of the coated pane.

[0176] The present invention thus also relates to a method to reduce optical distortion upon thermal treatment of a base pane comprising a first main face comprising a first area coated witha multilayer functional coating and a second area devoid of said multilayer functional coating, by providing for a transition area between said first and second areas, wherein the transition area comprises subareas, having surfaces, provided with multilayer functional coating or devoid of multilayer functional coating.EXAMPLESExamples 1 and 2 - Comparative example 1

[0177] Optical distortion was measured according to ASTM C1652 method, using ISRA Vision detector, measuring the optical power (in millidioptre - mdpt).

[0178] Optical distortion is considered acceptable below the maximum of 200 mdpt. Specific requirements may provide for targets of 110 mdpt, or even 60-70 mdpt.

[0179] A clear float glass pane of 2.1 mm was provided with an infrared reflective coating comprising two silver layers, each embedded within dielectric layers, on a first are of a first main face, and on a transition area, transitioning smoothly into a second area devoid of said infrared reflective coating.

[0180] The coating was provided on the glass pane using physical vapor deposition.

[0181] The pane was subsequently bent at a temperature of 640°C for 295 seconds.

[0182] ln Comparative Example 1 , there was no transition area, such that the edge of the first area to the second area consisted in a sharp line between said areas.

[0183] ln Example 1 , the transition area consisted of subareas having a geometrical design of circles pattern of maximum 3.87 mm radius, and minimum 2.5 mm radius, and intermediate 3.25 mm radius. The transition area extended over a width of 12 mm from the edge of the first area to the second area.

[0184] ln Example 2, the transition area consisted of subareas having a geometrical design of parallel lines pattern of evolving thicknesses, namely 1 mm width, 2 mm width and 3 mm width. The transition area extended over a width of 14 mm from the edge of the first area to the second area, with increasing thickness of the coated lines towards the first surface, such that the transition area could blend into the first area with no sharp edge.

[0185] Optical distortion was assessed, and results were compiled in Table 1 , with the average, maximum and minimum distortion in millidiopters (mdpt).TABLE 1

[0186] Examples 1 and 2 demonstrated lower values of optical distortion indicating the transition area allows for smoother transition of the first area to the second area, as compared to Comparative Example 1 , free of transition area. The distortion was reduced by a 5.6% range for Example 1 , as compared to Comparative Example 1 , while it was of 11.3% for Example 2.

[0187] This evidences the practical advantage of the transition area, to reduce the optical distortion by at least 5 to 10%, and particularly useful when the multilayer functional coating is an infrared reflective coating based on at least one metallic functional layer.

[0188] The reduction may be even further improved by adjusting the pattern of the transition area.

Claims

CLAIMS1 . A coated pane comprising:- a base pane comprising a first main face and a second main face, opposite said first face;- a first area of the first main face of the base pane coated with a multilayer functional coating;- a second area of the first main face of the base pane devoid of a multilayer functional coating, characterized in that it further comprises a transition area between the first and second areas of the first main face of the base pane, said transition area comprising subareas, having surfaces, provided with multilayer functional coating or devoid of multilayer functional coating.

2. The coated pane according to any one of the preceding claims, wherein the subareas of the transition area form a geometrical design.

3. The coated pane according to any one of the preceding claims, wherein the geometrical design comprises patterns of discrete circles, dots, triangles, squares, rectangles, pentagons, hexagons, octagons, ovals, waves, straight or curved lines, jigsaws, shapes, letters, logos, etc.

4. The coated pane according to any one of the preceding claims, wherein the transition area has a width ranging of from 1 to 45 mm, preferably from 3 to 40 mm, more preferably from 5 to 35 mm, more preferably from 6 to 25 mm, even more preferably from 7 to 20 mm, still more preferably from 8 to 16 mm.

5. The coated pane according to any one of the preceding claims, wherein the multilayer functional coating is an infrared reflective coating based on at least one metallic functional layer; or an infrared reflective coating based on at least one transparent conductive oxide functional layer; or an infrared antireflective coating.

6. The coated pane according to claim 5, wherein the infrared reflective coating based on at least one metallic functional layer comprises n metallic infrared reflective layers and n + 1 dielectric layers, with n > 1 , such that each metallic infrared reflective layer is surrounded by two dielectric layers.

7. The coated pane according to claim 6, wherein the metallic infrared reflective layer is made of silver, gold, palladium, platinum or alloys thereof.

8. The coated pane according to any one of the preceding claims, wherein the second area devoid of any coating.

9. The coated pane according to any one of the preceding claims, wherein the base pane comprises float glass, preferably infrared transmissive glass.

10. A laminated pane comprising1)the coated pane according to any one of claims 1 to 9,2)a thermoplastic material,3)a second pane comprising a first main face and a second main face, opposite said first face, where the thermoplastic material bonds the two panes together by adhering a main face of the base pane to a main face of the second pane.

11. The laminated pane according to claim 11 , wherein the second pane comprises float glass, preferably infrared transmissive glass.

12. Method for producing a coated pane, comprising, in sequence, the steps of:1) providing for a base pane comprising a first main face and a second main face, opposite said first face,2) providing for a masking coating on at least a second area of the first main face of the base pane, said masking coating comprising a geometrical design to transition from the at least second area of the first main face (masked area) to a first area of the first surface (unmasked area),3) providing for a multilayer functional coating over at least part of the first main face of the base pane which is covered by the masking coating and over at least part of the first main face of the base pane which is free of the masking coating,4) removing the masking coating which is covered by the multilayer functional coating, from the base pane,5) subjecting the base pane to a thermal treatment.

13. Use of the coated pane according to any one of claims 1 to 9, as a window pane in architectural or transport applications.

14. Use of the laminated pane according to any one of claims 10 to 11 , as a window pane in architectural or transport applications.

15. Use of a transition area between a first area coated with a multilayer functional coating and a second area devoid of said multilayer functional coating on a first main face of a base pane, said transition area comprising subareas, having surfaces, provided with multilayer functional coating or devoid of multilayer functional coating, to reduce optical distortion upon thermal treatment of said base pane.

Images