Low emissivity and solar radiation prevention glazing

Abstract

The present invention relates to a glazing unit comprising a transparent substrate (1), wherein the transparent substrate (1) has only two infrared radiation reflecting functional layers, called the first functional layer Ag1 (5) and the second functional layer Ag2 (11), starting from the substrate surface, such that each functional layer is surrounded by a dielectric coating, and a laminate of thin layers comprising, in an alternating configuration, three dielectric coatings called D1, D2 and D3 starting from the substrate surface, the two functional layers containing silver and only D1 and D2 each containing one layer of an absorbing material. In the glazing unit, D1 comprises, in order, a lower absorber layer sequence BA (2) in direct contact with the substrate and a contact layer C1 (4) containing zinc oxide, which is directly below and in contact with the first functional layer Ag1 (5) above it. D2 comprises, in order, a contact layer C2 (6) containing zinc oxide, which is directly above and in contact with the first functional layer Ag1 (5) below it, an intermediate absorber layer sequence MA, and a contact layer C3 (10) containing zinc oxide, which is in contact with the second functional layer Ag2 (11). And D3 comprises, in order, a contact layer C4 (12) containing zinc oxide, which is directly above and in contact with the second functional layer Ag2 (11) below it. It is characterized in that BA (2) contains a first layer AM1 of an absorbing material inserted into a first silicon nitride-containing layer SiN1, and MA (8) further contains a second layer AM2 of an absorbing material inserted into a second silicon nitride-containing layer SiN2.

Description

Technical Field

[0001] The present invention relates to a glazing system having solar radiation prevention characteristics, having a low visible reflectance on both surfaces of the glazing, and being heat-treatable. These glazings having a low light transmittance can be incorporated into building windows or used in the field of automotive glazing.

Background Art

[0002] International Publication No. 2020157440A1 pamphlet describes glazings having solar radiation prevention characteristics. These glazings include one sequence, namely a first dielectric coating, a first silver layer, a second dielectric coating, a second silver layer, and a third dielectric coating. These laminates further include two absorption layers in two dielectric coatings in order to achieve the required low reflectance and energy characteristics. However, the laminate of International Publication No. 2020157440A1 pamphlet further includes NiCr barrier layers above and below each silver layer. Despite the description in International Publication No. 2020157440A1 pamphlet, it is well known that these NiCr barrier layers provide light absorption, and in the case of NiCr, k = 3.5, and thus also participate as an additional absorption layer in addition to their barrier layer function.

[0003] In some cases, in order to improve the resistance to mechanical stress, operations are required to mechanically reinforce the glazing, such as heat strengthening of one or more glass sheets. For certain applications, it may be necessary to use bending operations at high temperatures to impart more or less complex bends to the glass sheet. In the process of producing and forming a glazing system, there are certain advantages to performing these heat treatment operations on the already coated substrate instead of coating the already treated substrate. These operations are carried out at relatively high temperatures, which is a temperature at which functional layers based on infrared reflective materials, such as those based on silver, tend to deteriorate and lose their optical and infrared emission related properties. These heat treatments specifically include heating the glass sheet in air to a temperature above 560 °C, such as 560 °C - 700 °C, specifically 640 °C - 670 °C, for a period of about 3, 4, 6, 8, 10, 12 minutes or even 15 minutes, depending on the type of treatment and the thickness of the sheet. In the case of the bending treatment, the glass sheet can then be bent into the desired shape. The strengthening treatment then consists of rapidly cooling the surface of the flat or bent glass sheet with an air jet or a cooling fluid in order to obtain mechanical reinforcement of the sheet.

[0004] Therefore, if the coated glass sheet has to undergo heat treatment, in many cases, extremely special precautions, hereinafter referred to by the term "annealable", have to be taken in order to form a coating structure that can withstand heat strengthening and / or bending treatment without losing the optical and / or energy properties generated therefor. Specifically, the dielectric materials used to form the dielectric coating must withstand the high temperatures of the heat treatment without exhibiting any adverse structural changes. In the pamphlet of International Publication No. WO 2020 / 157440 A1, the NiCr barrier layer induces a large change in optical properties, specifically a reduction in light absorption, during annealing while the necessary light absorption is being achieved. Further changes during annealing of these coatings are due to the oxidation of the absorber layer in contact with the oxide layer. As a result, these coatings are not annealable.

[0005] Another requirement that must be considered is, in many cases, the result of the fact that non-heat-treated products and other heat-treated ones must be combined with each other for the same use, for example within the same building facade. For such buildings, it is very interesting to provide glazing that includes a self-consistent coating, which is a coating having very similar aesthetic properties regardless of whether they are heat-strengthened or not. The coating of WO 2020 / 157440 A1 pamphlet is not self-consistent.

[0006] In addition, the formation of such solar control coatings must result in colors that are satisfactory in both reflection and transmission, in line with the need to tend towards the most complete neutrality possible. The challenge is to combine the colorimetric requirements with those associated with the "base" conditions, i.e., all of desirable light transmission, low reflectivity, and the ability to withstand heat treatment.

[0007] Therefore, there is a need in the art to provide solar control glazing that has a low reflectivity, is aesthetically pleasing, is temperable, and preferably is self-consistent. SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to develop a new type of solar control laminate that is effective in terms of optical and energy properties and is temperable. The resulting glazing may specifically have a low level of reflectivity and / or high selectivity. The solar control glazing preferably also has a low light transmission of 40% or less.

[0009] The following information is used in the present invention. a. Light transmission (LT) is the percentage of the incident light beam at illuminant D65 / 2° transmitted by the glazing. b. Light reflectance (LR) is the percentage of the incident light beam at illuminant D65 / 2° reflected by the glazing. This can be measured from the layer side (LRc) or the substrate side (LRg) on a single glazing. Specifically, this can be measured on the external side (LRext) of a building or vehicle or on the internal side (LRint) of a building on a plurality of glazing units or laminated glazing. c. Energy transmittance (ET) is the percentage of the incident energy radiation transmitted by the glazing, calculated in accordance with standard EN410. d. Energy reflectance (ER) is the percentage of the incident energy radiation reflected by the glazing, calculated in accordance with standard EN410. This can be measured on the external side (ERext) of a building or vehicle or on the internal side (ERint) of a building or vehicle. e. Solar factor (SF or g) is, on the one hand, the percentage of the incident energy radiation directly transmitted by the glazing, absorbed thereby, and then radiated in the opposite direction to the energy source in relation to the glazing. Here, this is calculated in accordance with standard EN410. f. Selectivity = LT / SF. g. CIELAB1976 values (L*a*b) are used to define the tint. These are measured at illuminant D65 / 10°. h. ΔE * = [(L * ) 2 + (a * ) 2 + (b * ) 2 1 / 2 represents the variation of the tint during heat treatment, i.e., the difference in color before and after heat treatment. i. The resistance value per square (R2) (the "sheet resistance value") expressed in ohms per square (Ω / □) measures the electrical resistance value of a thin film.

[0010] When values are referred to as being "in the range of a to b", these may be equal to a or b.

[0011] The positioning of the stack of layers within the plurality of glazing structures is given according to the conventional numbering method of the faces of the glazing unit, where face 1 is on the outside of the building or vehicle, and face 4 (in the case of a double glazing unit) or face 6 (in the case of a triple glazing unit) is on the inside.

[0012] When referring to the silicon nitride layer in this specification, it should be understood that, as is well known in the technical field of magnetron sputtering coatings, the layer may incorporate a small amount of aluminum. Such aluminum is generally included in an amount of up to 10% by weight, relative to the weight of Si and Al, as a doping agent.

[0013] For the sake of clarity, when terms such as "lower", "upper", "below", "above", "down", "up", "first" or "last" are used in this specification, they always relate to a sequence of layers starting from the lower glass and progressing upwards and further away from the glass. Such a sequence may include additional intermediate layers between the defined layers, except where direct contact is specified.

[0014] The present invention relates to a glazing unit according to claim 1 and the dependent claims and to a preferred embodiment.

[0015] In a glazing unit comprising a transparent substrate (1), wherein the transparent substrate (1) is provided with a laminate of thin layers in an alternating configuration comprising only two infrared radiation reflecting functional layers, designated as the first functional layer Ag1 (5) and the second functional layer Ag2 (11), starting from the substrate surface, and three dielectric coatings designated as D1, D2 and D3, starting from the substrate surface, such that each functional layer is surrounded by a dielectric coating and thus forms a sequence of D1 / Ag1 / D2 / Ag2 / D3 starting from the substrate, the two functional layers contain silver and only D1 and D2 each contain one layer of an absorbing material. a. D1 includes, in order, a lower absorber layer sequence BA(2) that directly contacts a substrate, and a contact layer C1(4) containing zinc oxide that is directly below and in contact with a first functional layer Ag1(5) above it. b. D2 includes, in order, a contact layer C2(6) containing zinc oxide that is directly above and in contact with a first functional layer Ag1(5) below it, an intermediate absorber layer sequence MA, and a contact layer C3(10) containing zinc oxide that is below and in contact with a second functional layer Ag2(11). c. D3 includes, in order, a contact layer C4(12) containing zinc oxide that is directly above and in contact with a second functional layer Ag2(11) below it. It is characterized in that BA includes a first layer AM1 of an absorption material inserted into a first silicon nitride-containing layer SiN1, and MA further includes a second layer AM2 of an absorption material inserted into a second silicon nitride-containing layer SiN2, relating to a glazing unit.

[0016] The lower absorber layer sequence BA includes a first layer of an absorption material inserted into a first silicon nitride-containing layer SiN1, which means that SiN1 is separated into two parts. One part of SiN1 is below and in contact with AM1, and another part of SiN1 is above and in contact with AM1. In other words, the first layer AM1 of the absorption material is located between two sub-layers of the first silicon nitride-containing layer, namely a lower sub-layer SiN1a and an upper sub-layer SiN1b.

[0017] The intermediate absorber layer sequence MA includes a second layer of an absorption material inserted into a second silicon nitride-containing layer, which means that SiN2 is separated into two parts. One part of SiN2 is below and in contact with AM2, and another part of SiN2 is above and in contact with AM2. In other words, the second layer AM2 of the absorption material is located between two sub-layers of the second silicon nitride-containing layer, namely a lower sub-layer SIN2a and an upper sub-layer SiN2b.

[0018] For the purpose of clarity, the laminate of the layers of the present invention includes only two layers of absorbent material. This means that only D1 and D2 each contain one layer of absorbent material, and D3 does not contain a layer of absorbent material.

[0019] According to one embodiment of the present invention, D1 includes a first layer ZSO1(3) containing a mixed oxide of zinc and tin, between BA(2) and C1(4) and optionally in contact with BA(2) and / or C1(4).

[0020] According to one embodiment of the present invention, D2 includes a second layer ZSO2(7) containing a mixed oxide of zinc and tin, between C2(6) and MA(8) and optionally in contact with C2(6) and / or MA(8).

[0021] According to one embodiment of the present invention, D2 includes a third layer ZSO3(9) containing a mixed oxide of zinc and tin, above MA(8) and optionally in contact with it, and optionally below C3(10) and in contact with it.

[0022] According to one embodiment of the present invention, D3 includes a fourth layer ZSO4(13) containing a mixed oxide of zinc and tin, above C4(12) and in contact with it.

[0023] According to one embodiment of the present invention, D3 includes a layer SiN3(14) containing silicon nitride, above C4(12), and optionally above and in contact with ZSO4(13).

[0024] According to one embodiment of the present invention, D3 includes a top layer TL(15) containing a metal oxide or a metal nitride. TL can be the uppermost layer in the laminate or the uppermost permanent layer in the laminate.

[0025] According to one embodiment of the present invention, the thin layer laminate includes a temporary protective layer. Such a temporary protective layer can protect the thin layer laminate during the conveyance or operation of the glazing. The temporary protective layer can be removed during heat treatment. This may include, for example, a carbon layer or a polymer layer that can burn out during heat treatment.

Brief Description of the Drawings

[0026]

Figure 1

[0027]

Figure 2

[0028]

Figure 3

Embodiments for Carrying Out the Invention

[0029] By a specific selection of the layers of the coating laminate, specifically the absorber layer sequence and the composition of the layer in contact with the functional layer, the following advantages are shown before or after heat treatment on the glazing unit, and thus a laminate (a laminate of the layers at position 2, a standard 6 mm thick clear soda lime float glass sheet incorporated in a double glazing unit having another standard 6 mm thick clear soda lime float glass sheet, and there is a coating on the standard 6 mm thick clear soda lime float glass sheet, and the space between the 12 mm glass sheets is filled with air up to 100%) that can provide these can be obtained. a. A small solar factor SF to enable reduction of the risk of excessive overheating as a result of solar radiation, where SF ≦ 21%, preferably SF ≦ 19.5%, more preferably ≦ 18.5%, b. A low visible light reflectance for both LRext and LRint, where LRext and LRint are independently 13% - 18%, preferably LRint is 10% - 17%, c. A high selectivity where LT / SF ≥ 1.3, preferably LT / SF ≥ 1.4 (the ratio of visible light transmittance LT to solar heat gain coefficient SF), d. A transmittance where 40% ≥ LT ≥ 20% of visible light, e. Transmittance (LT) 40 ≤ L * LT ≥ 80, -4.1 ≤ a * LT ≥ -0.5, -1.3 ≤ b * LT ≤ 4.8, preferably 50 ≤ L * LT ≤ 70, -3.5 ≤ a * LT ≤ -0.5, -1.2 ≤ b * LT ≤ 4.5, for the color values L * , a * , b * , f. External reflection (LRext) 35 ≤ L * LRext ≤ 60, -2.3 ≤ a * LRext ≤ -0.5, -9.3 ≤ b * LRext ≤ -3.0, preferably 40 ≤ L * LRext ≤ 52, -2.0 ≤ a * LRext ≤ -0.6, -7.8 ≤ b * LRext ≤ -3.7, for the color values L * , a * , b * , g. Internal reflection (LRint) 35 ≤ L * LRint ≤ 60, -13.7 ≤ a * LRint ≤ 2.3, -15.1 ≤ b * LRint ≤ -1.6, preferably 40 ≤ L * LRint ≤ 55, -11.5 ≤ a * LRint ≤ 2.0, -12.7 ≤ b * LRint ≤ 1.5, for the color values L * , a * , b * , h. It is heat - treatable, and the coating has resistance to high temperatures or is used without heat treatment, i. It has a beautiful appearance without defects, has very limited or no haze without or after heat treatment, and lacks unacceptable spots after heat treatment, j. Retention of optical and energy properties that are substantially unchanged after heat treatment, thereby allowing the use of the product with or without heat treatment ( "self - consistency"), with no or only slight color changes (ΔE * ≤8, preferably ≤5, more preferably ≤2) in transmission and reflection measured in a single glazing configuration, and / or no or only slight changes (Δ = |(value before heat treatment)-(value after heat treatment)|≤7, preferably ≤6) in light transmission, reflection and energy values. k. Sufficient chemical stability for use without heat treatment or during the time interval before heat treatment, and specifically not imparting any visible defects or any discoloration to the naked eye after 1 day, preferably after 3 days, as a result of the climatic chamber test or salt spray test according to standard EN1036 - 2012.

[0030] The inventors have actually found that it is not only beneficial to provide a layer of absorber material in the first two dielectrics of the thin - layer laminate, but also beneficial to enclose the layer of absorber material within the silicon nitride layer and, at the same time, enclose the functional layer within the zinc oxide layer. This configuration of the layers specifically contributes to ensuring the heat - treatability of the thin - layer laminate.

[0031] Figure 1 shows a transparent substrate (1) coated with a layer sequence comprising a lower absorption layer sequence BA(2), a layer ZSO1(3) of mixed zinc tin oxide, a contact layer C1(4) containing zinc oxide, a first functional layer Ag1(5), a contact layer C2(6) containing zinc oxide, a second layer ZSO2(7) containing a mixed oxide of zinc, an intermediate absorption layer sequence MA(8), a third layer ZSO3(9) containing a mixed oxide of zinc and tin, a contact layer C3(10) containing zinc oxide, a second functional layer Ag2(11), a contact layer C4(12) containing zinc oxide, a fourth layer ZSO4(13) containing a mixed oxide of zinc and tin, a layer SiN3(14) containing silicon nitride, and a top layer TL(15) containing a metal oxide or metal nitride.

[0032] Figure 2 shows in detail a lower absorption layer sequence BA(2) comprising a first layer AM1(22) of absorption material inserted within a first silicon nitride-containing layer SiN1, which means that SiN1 is separated into two sub-layers of the first silicon nitride-containing layer, namely a lower sub-layer SIN1a(21) and an upper sub-layer SiN1b(23).

[0033] Figure 3 shows in detail a lower absorption layer sequence MA(8) comprising a first layer AM1(82) of absorption material inserted within a first silicon nitride-containing layer SiN1, which means that SiN1 is separated into two sub-layers of the first silicon nitride-containing layer, namely a lower sub-layer SIN1a(81) and an upper sub-layer SiN1b(83).

[0034] It should be noted that the present invention relates to all possible combinations of the features described in the claims.

[0035] Individual layers of the laminate of the present invention are preferably deposited by magnetron sputtering. Metal or metal alloy layers are typically deposited from a metal or metal alloy sputtering target in an inert gas atmosphere. Oxide layers are typically deposited from a metal, metal alloy or silicon target in an atmosphere containing oxygen mixed with an inert gas such as argon or krypton. Alternatively, the oxide layer may be deposited from a ceramic oxide target in an inert gas atmosphere optionally containing oxygen. Nitride layers are typically deposited from a metal, metal alloy or silicon sputtering target in an atmosphere containing nitrogen mixed with an inert gas such as argon or krypton.

[0036] According to one embodiment of the present invention, the functional layer is essentially composed of silver.

[0037] According to one embodiment of the present invention, the transparent substrate is made of glass. The glass matrix composition is not particularly limited and can thus belong to different glass categories. The glass can be soda-lime-silicate glass, aluminosilicate glass, alkali-free glass, borosilicate glass, etc. Preferably, the glass sheet of the present invention is made of soda-lime glass.

[0038] According to an advantageous embodiment of the present invention, which can be combined with the above embodiments, the glass sheet has a composition comprising a total iron content (expressed with respect to Fe2O3) in the range of 0.002 to 0.06 wt%. A total iron content of 0.06 wt% or less (expressed in the form of Fe2O3) makes it possible to obtain a glass sheet with little visible coloring. Preferably, the composition comprises a total iron content (expressed in the form of Fe2O3) in the range of 0.002 to 0.04 wt%. More preferably, the composition comprises a total iron content (expressed in the form of Fe2O3) in the range of 0.002 to 0.020 wt%. In the most preferred embodiment, the composition comprises a total iron content (expressed in the form of Fe2O3) in the range of 0.002 to 0.015 wt%.

[0039] According to a preferred embodiment, the transparent substrate of the present invention is a float glass sheet. The transparent substrate according to the present invention, such as a glass sheet, for example, may have a thickness of 0.1 to 25 mm.

[0040] The layer of the absorbing material in its specific configuration aids in reducing the visible light transmittance of the laminate and simultaneously reducing the reflectance of the coated glazing.

[0041] According to one embodiment of the present invention, the total geometric thickness ΣAM of AM1 and AM2 is in the range of 2.4 to 6.1 nm, preferably 2.4 to 5.8 nm, more preferably 2.9 to 5.2 nm. The inventors have found that an overly large ΣAM tends to degrade the selectivity value, while an overly low ΣAM does not allow sufficient reduction of LT for solar control glazing.

[0042] According to one embodiment of the present invention, the geometric thickness of AM1 is in the range of 0.5 to 1.8 nm, preferably 1.2 to 1.8 nm.

[0043] According to one embodiment of the present invention, the geometric thickness of AM2 is in the range of 0.5 to 4.4 nm, preferably 1.6 to 3.6 nm.

[0044] According to one embodiment of the present invention, the layer of the absorbing material may specifically include Nb, Ti, titanium nitride, niobium nitride, an alloy of Ni and Cr (NiCr alloy) or an alloy of Ni, Cr and W (NiCrW alloy) or a nitride of an alloy of Ni and Cr (NiCrN) or a nitride of an alloy of Ni, Cr and W (NiCrWN).

[0045] The absorbers TiN, NbN, and Nb reach 1.5 ≦ n ≧ 4.5 and 1.0 ≦ k ≦ 2.0. More preferred absorbers of Ti, NiCr, nitrides of NiCr, and nitrides of NiCrW reach 2.5 ≦ n ≧ 3.5 and 2.5 ≦ k ≦ 3.5, which means they are more efficient absorbers with a smaller impact on reflectivity as a smaller thickness is required to reach the desired absorption level. As is common in the art, n is the real part of the refractive index of a given material, while k is the imaginary part. Here, n and k are considered for a wavelength of 550 nm.

[0046] The absorbing material can be composed of an alloy of Ni, Cr, and W (NiCrW alloy) or a nitride of the alloy, and can contain 30 wt% to 90 wt%, preferably 40 wt% to 70 wt%, advantageously 45 wt% to 65 wt% of tungsten, and nickel, and chromium, at nickel / chromium weight ratios of 100 / 0 and 50 / 50, preferably 80 / 20. NiCrWN, which is a nitride of the NiCrW alloy, can contain up to 20 wt% of nitrogen. NiCrWN can be unintentionally formed by a nitrogen atmosphere leaking from upstream / downstream of nitride sputtering deposition such that it reaches a maximum of only 10%, preferably a maximum of 5% nitrogen by weight.

[0047] The absorbing material can be composed of an alloy of Ni and Cr or a nitride of the alloy at Ni / Cr weight ratios of 99 / 1 and 50 / 50, preferably 80 / 20. NiCrN, which is a nitride of the NiCr alloy, can contain up to 20 wt%, preferably up to 10 wt% of nitrogen.

[0048] NiCrN and NiCrWN are particularly suitable absorbers because the risk of reaction with any roaming species of oxygen or nitrogen during heat treatment is minimized.

[0049] The material of the contact layers C1 - C4 containing zinc oxide, which is under or above any functional layer in the laminate of the layers of the present invention, can be independently selected from any of the following. a. Zinc oxide doped with aluminum at a weight ratio of at least 95 / 5, preferably at least 98 / 2 Zn / Al, b. Pure ZnO (denoted as iZnO), c. Zinc oxide (denoted as AZO) doped with aluminum at a ratio of at most 10 wt% or alternatively at most 5 wt%, preferably about 2 wt%.

[0050] These types of contact layers have the advantage of reducing changes in photo - energy properties, specifically color and transmittance, during heat treatment. Metal - based contact layers specifically show a high degree of change in photo - energy properties during heat treatment and also result in different degrees of oxidation / nitriding of any underlying metal layer, thus also requiring careful control of the deposition of the overlying oxide and nitride layers. Furthermore, these zinc - oxide - based contact layers result in a more controlled growth of the overlying functional layer, whereby a smaller functional layer thickness is required to reach the desired degree of emissivity.

[0051] The contact layer can be obtained by sputtering from a metal target of zinc optionally doped with aluminum in an oxygen - containing atmosphere. Alternatively, the contact layer can also be obtained by sputtering a ceramic target of zinc oxide doped with aluminum in a non - oxidizing atmosphere. This is preferred when depositing the contact layer on a silver layer.

[0052] According to one embodiment of the present invention, the thickness of the contact layer containing zinc oxide is preferably at most 10 nm, more preferably at most 8 nm, and even more preferably at most 6 nm.

[0053] According to one embodiment of the present invention, the thickness of the contact layer containing zinc oxide is at least 2 nm, more preferably at least 3 nm.

[0054] According to one embodiment of the present invention, the thickness of D1 is 40 - 68 nm, preferably 49 - 57 nm.

[0055] According to an embodiment of the present invention, the thickness of D2 is 65 to 130 nm, preferably 75 to 122 nm, and more preferably 93 to 102 nm.

[0056] According to an embodiment of the present invention, the thickness of D3 is 25 to 44 nm, preferably 31 to 37 nm.

[0057] Preferably, the thickness of D2 is greater than the thicknesses of D1 and D3.

[0058] Preferably, the ratio of the thickness of D1 to the thickness of D3 is 0.8 to 1.4.

[0059] The thicknesses of Ag1 and Ag2 can be adjusted individually and / or together to obtain desired energy and optical properties. An overly small silver thickness has been found to be detrimental to the solar heat gain coefficient, while an overly large silver thickness tends to increase the light reflectance. According to an embodiment of the present invention, the thicknesses of Ag1 and Ag2 are each 13 to 30 nm. Advantageously, the thickness of Ag1 is 14 to 30 nm, more advantageously 14 to 25 nm. Advantageously, the thickness of Ag2 is 13 to 20 nm, more advantageously 13 to 17 nm.

[0060] Advantageously, the total ΣAg of the thicknesses of Ag1 and Ag2 is in the range of 23.3 to 40.8 nm, preferably 27 to 37.5 nm, and more preferably 28.5 to 34.5 nm.

[0061] Advantageously, the thickness ratio of Ag1 to Ag2 is in the range of 0.8 to 1.8, preferably 1.0 to 1.5.

[0062] In one embodiment of the present invention, the ratio of the total thickness of the absorber layers AM1 and AM2 to the total thickness of Ag1 and Ag2 is in the range of 0.07 to 0.19, preferably 0.07 to 0.16, and more preferably 0.09 to 0.16. A higher ratio tends to reduce the selectivity.

[0063] In an advantageous embodiment of the present invention, the geometric thickness of the silicon nitride layer SiN1 is 21 to 59 nm, preferably 26 to 50 nm.

[0064] In an advantageous embodiment of the present invention, the geometric thickness of the silicon nitride layer SiN2 is 20 to 40 nm, preferably 25 to 36 nm, more preferably 28 to 34 nm.

[0065] In a preferred embodiment of the present invention, the layer of zinc - tin mixed oxide is a layer (Zn2SnO4) with a zinc - tin ratio close to 50 - 50 wt%, for example 52 - 48 wt%. The zinc - tin mixed oxide can be advantageous in that it has a good deposition rate compared to, for example, SiO2 or Al2O3, and has good chemical stability compared to, for example, pure ZnO or bismuth oxide. Further, this can be advantageous in that it has a lower tendency to generate haze after heat treatment of the laminate compared to, for example, oxides of Ti or Zr.

[0066] C1 and C3, which are below and in contact with Ag1 and Ag2 respectively, are often referred to as "nucleation" or "wetting" layers, which assist the growth of the silver above them and assist in increasing the sheet resistance value of the product.

[0067] In one embodiment of the present invention, C1, C2, C3 and / or C4 are composed of zinc oxide or alternatively doped with other metals such as aluminum, for example, generally up to 10 wt%, preferably about 2 wt%.

[0068] In one embodiment of the present invention, C1, C2, C3 and / or C4 have a thickness in the range of up to 15 nm, preferably 1.5 to 10 nm, more preferably 3 to 10 nm.

[0069] Within D1, D2 and D3, any of the first, second and third silicon nitride - containing layers is not necessarily stoichiometric and may contain other elements. The silicon nitride - containing layers in the laminate of the present invention can specifically prevent oxygen from moving through the laminate towards the absorber layer, especially during heat treatment.

[0070] In one embodiment of the present invention, these silicon nitride-containing layers are Si3N4, Si with an atomic ratio of Si / N in the range of 0.6 to 0.9, preferably 0.7 to 0.8 x N y and are selected from among mixed nitrides of silicon and zirconium having a Si / Zr weight ratio in the range of 70 / 30 to 50 / 50, preferably in the range of 65 / 35 to 55 / 45. These silicon nitride-containing layers may contain aluminum at a weight ratio of Al / Si of up to 10%.

[0071] In a preferred embodiment of the present invention, within D1, D2, and D3, any of the first, second, and third silicon nitride-containing layers preferably contains silicon and nitrogen with an atomic ratio of Si / N of at least 0.72 and at most 0.78, close to stoichiometric Si3N4, preferably the atomic ratio of Si / N is at least 0.74 and at most 0.76. This provides low visible absorption and, in addition, reduces the amount of color change during heat treatment compared to Si x N y further away from stoichiometry.

[0072] According to one embodiment of the present invention, the thickness of any of the silicon nitride-containing layers SiN1 and SiN2 is at least 20 nm, preferably at least 28 nm. Such a minimum thickness may be required to provide the beneficial effects of these layers.

[0073] According to one embodiment of the present invention, the thickness of any of the silicon nitride-containing layers SiN1 and SiN2 is at most 50 nm, preferably at most 40 nm. Such a thickness may be required, specifically, to limit the intrinsic stress within these layers that can lead to mechanical and / or chemical durability degradation due to the presence of three silicon nitride-containing layers in the laminate.

[0074] According to a preferred embodiment of the present invention, in D1, AM1 is inserted into the first silicon nitride layer SiN1 such that at least 10 nm of the thickness of the first silicon nitride layer is located below the AM1 layer and at least 10 nm of the thickness of the silicon nitride layer is located above it.

[0075] According to a preferred embodiment of the present invention, in D2, AM2 is inserted into the second silicon nitride layer SiN2 such that at least 10 nm of the thickness of the second silicon nitride layer is located below the nitride layer and at least 10 nm of the thickness of the second silicon nitride layer is located above it.

[0076] Inserting the absorber layer into the silicon nitride layer protects the absorber layer from oxidation not only during the deposition of the subsequent oxide layer but also during heat treatment.

[0077] In one embodiment of the present invention, in D1, D2, and D3, any of the first, second, and third layers containing a mixed oxide of zinc and tin contains a mixed oxide of zinc and tin, and the weight ratio of zinc to tin Zn / Sn can be in the range of 1 / 9 to 9 / 1. Advantageously, the zinc-tin ratio is close to 50 wt%-50 wt%, for example, 52-48 wt%, and is composed of, for example, Zn2SnO4.

[0078] According to one embodiment of the present invention, in D1, D2, and D3, any one or more of the first, second, and third layers containing a mixed oxide of zinc and tin have a thickness of at least 10 nm, more preferably at least 20 nm. The thickness is preferably at most 50 nm, more preferably at most 45 nm.

[0079] According to a preferred embodiment of the present invention, in D1, the first layer ZSO1 containing a mixed oxide of zinc and tin has a thickness of at least 20 nm, more preferably at least 25 nm. Further, the thickness can be at most 60, preferably at most 50 nm, more preferably at most 45 nm.

[0080] According to a preferred embodiment of the present invention, within D2, the second layer ZSO2 containing a mixed oxide of zinc and tin has a thickness of at least 10 nm, more preferably at least 15 nm. Further, the thickness can preferably be at most 45 nm, preferably at most 40 nm.

[0081] According to a preferred embodiment of the present invention, within D2, the third layer ZSO3 containing a mixed oxide of zinc and tin has a thickness of at least 1 nm, more preferably 3 nm. Further, the thickness can preferably be at most 12 nm, more preferably at most 10 nm, even more preferably at most 8 nm.

[0082] According to an embodiment of the present invention, within D3, the top layer TL containing a metal oxide or a metal nitride is a layer containing titanium and / or zirconium or a mixed oxide of silicon and zirconium or a mixed nitride of silicon and zirconium. Such a layer specifically provides mechanical protection to the layer laminate.

[0083] According to an embodiment of the present invention, the metal oxide or metal nitride top layer of D3 is the last layer, i.e., the outermost layer, of the laminate. However, temporary protection means such as a removable plastic film or a carbon film can be provided on this last permanent layer.

[0084] In an advantageous embodiment of the present invention, the top coat contains at least TiO y and ZrO z and, optionally, SiO x where x, y, z can range from 1.8 to 2.2, and the top coat, for a total of 100% of the metal, a. 8 to 49% titanium, b. 51 to 92% zirconium, c. 0 to 9% silicon and has a thickness of 0.1 to 10 nm in order to improve durability by increasing the wear resistance by at least 20%, alternatively at least 30%, alternatively at least 40%.

[0085] In some embodiments of this method of use that are compatible with other embodiments of the present invention, the above ranges of Ti, Zr, and Si in the topcoat can vary independently from one to the other. The amount of Ti can alternatively be in the range of 10 - 47% or 12 - 46%. Alternatively, the amount of Zr can be in the range of 53 - 90%. The amount of Si can alternatively be in the range of 1 - 8%, alternatively 2 - 7%. Thus, when the total is 100% of the metal containing impurities as described above, these amounts can vary independently for each metal.

[0086] In an advantageous embodiment of the present invention, the metal oxide or metal nitride top layer of D3 is, for example, TiO close to 65 / 35 y / ZrO z and is composed of an oxide or substoichiometric oxide of at least one element selected from Ti and Zr, more preferably a mixed oxide of titanium - zirconium. Such a layer can provide certain good chemical and / or mechanical stability for glazing.

[0087] A trace amount of yttrium may be present in any Zr - containing layer of this laminate.

[0088] In another advantageous embodiment of the present invention, the metal oxide or metal nitride top layer of D3 is composed of a mixed nitride of silicon and zirconium. Advantageously, the mixed nitride of silicon and zirconium has an Si / Zr atomic ratio of at least 1 or at least 4. Advantageously, the mixed nitride of silicon and zirconium has an Si / Zr atomic ratio of at most 12 or at most 6.

[0089] In another advantageous embodiment of the present invention, the metal oxide or metal nitride top layer of D3 is composed of a mixed oxide of silicon and zirconium that can contain 5 - 50 mol%, preferably 8 - 20 mol% of zirconium oxide. The layer of the mixed oxide of silicon and zirconium can have a geometric thickness in the range of 1 - 10 nm, alternatively 1.5 - 8 nm.

[0090] The top layer within D3 preferably has a geometric thickness of at least 1 nm, preferably at least 1.5 nm. The geometric thickness is at most 5 nm, advantageously at most 3 nm.

Examples

[0091] Hereinafter, specific embodiments of the present invention will be described by way of example.

[0092] All thicknesses in the examples are given in nm. All layers were deposited using magnetic field-assisted cathodic sputtering under vacuum. Table 1 shows the sequence of layers and their composition of an exemplary laminate. Tables 2a and 2b below show the layer thicknesses of these examples.

[0093] TIFF2025525183000002.tif113170

[0094] TIFF2025525183000003.tif124170

[0095] TIFF2025525183000004.tif124170

[0096] TZO is a mixed oxide of titanium and zirconium having a TiO2 / ZrO2 weight ratio of 65 / 35.

[0097] NiCrW has 65 wt% W and a Ni / Cr weight ratio of 80 / 20.

[0098] Tables 3a and 3b below show the total thickness ΣAM of layers AM1 and AM2, the total thickness ΣAg of Ag1 and Ag2, and the ratio of ΣAM / ΣAg.

[0099] TIFF2025525183000005.tif51170

[0100] TIFF2025525183000006.tif52170

[0101] The following Tables 4a and 4b show the photo - energy characteristics of Examples 1 - 12 of the coating of the laminate of layers at position 2. The coating is present on a standard 6 - mm thick clear soda - lime float glass sheet incorporated within a double glazing unit having another standard 6 - mm thick clear soda - lime float glass sheet. The space between the 12 - mm glass sheets is filled with argon up to 90%. As can be observed, photo - energy characteristics within the desired range are obtained. Specifically, for transmittance values in the range of 21.1 - 30.5%, a low reflectance can be obtained along with a low solar heat gain coefficient.

[0102] TIFF2025525183000007.tif81170

[0103] TIFF2025525183000008.tif82170

[0104] Examples 1 - 12 can be heat - treated. Curing in a static oven at 670 °C for 7 minutes 30 seconds results in no or only slightly observable color changes in transmission and reflection in Examples 1 - 9, where ΔE * remains less than 2. Thus, these can be considered self - compatible.

[0105] Examples 10 - 12 show worse selectivity values, which appear in Examples 11 and 12 in relation to their larger ΣAM / ΣAg values and in Example 10 in relation to its large ΣAM. In Examples 6 and 10, LRext appears larger also due to their larger ΣAg values.

[0106] Examples 1 - 9 have sufficient chemical stability with or without heat treatment. In the climate chamber test and salt spray test according to EN1036 - 2012, no defects or discoloration are visible to the naked eye after 1 day.

Claims

1. A glazing unit comprising a transparent substrate (1), wherein the transparent substrate (1) is provided with a thin laminate comprising, starting from the substrate surface, two infrared radiation reflective functional layers referred to as a first functional layer Ag1 (5) and a second functional layer Ag2 (11), and three dielectric coatings referred to as D1, D2, and D3, in an alternating configuration, such that each functional layer is surrounded by a dielectric coating, wherein the two functional layers contain silver, and only D1 and D2 each contain one layer of an absorbing material, a. D1 includes, in order, a lower absorber layer sequence BA(2) that is in direct contact with the substrate, and a contact layer C1(4) containing zinc oxide that is directly below and in contact with the upper first functional layer Ag1(5). b. D2 includes, in order, a contact layer C2 (6) containing zinc oxide directly above and in contact with the first functional layer Ag1 (5) below, an intermediate absorber layer sequence MA, and a contact layer C3 (10) containing zinc oxide in contact with the second functional layer Ag2 (11), and c. D3 subsequently includes a contact layer C4 (12) containing zinc oxide, which is directly above and in contact with the lower second functional layer Ag2 (11). A glazing unit characterized in that BA(2) includes a first layer AM1 of absorbent material inserted within a layer SiN1 containing a first silicon nitride, and MA(8) includes a second layer AM2 of absorbent material inserted within a layer SiN2 containing a second silicon nitride.

2. The glazing unit according to claim 1, wherein the sum of the geometric thicknesses of AM1 and AM2 is in the range of 2.4 to 6.1 nm.

3. The glazing unit according to claim 1 or 2, wherein the sum of the geometric thicknesses of Ag1 and Ag2 is in the range of 23.3 to 40.8 nm.

4. The glazing unit according to claim 1 or 2, wherein the ratio of the sum of the geometric thicknesses of AM1 and AM2 to the sum of the geometric thicknesses of Ag1 and Ag2 is in the range of 0.07 to 0.

19.

5. The glazing unit according to claim 1 or 2, wherein D1 comprises a first layer ZSO1(3) containing a mixed oxide of zinc and tin, located between and in contact with BA(2) and C1(4).

6. The glazing unit according to claim 1 or 2, wherein D2 comprises a second layer ZSO2(7) containing a mixed oxide of zinc and tin, located between and in contact with C2(6) and MA(8).

7. The glazing unit according to claim 1 or 2, wherein D2 is located above and in contact with MA(8), and optionally below and in contact with C3(10), and comprises a third layer ZSO3(9) containing a mixed oxide of zinc and tin.

8. The glazing unit according to claim 1 or 2, wherein D3 comprises a fourth layer ZSO4(13) containing a mixed oxide of zinc and tin, located above and in contact with C4(12).

9. The glazing unit according to claim 1 or 2, wherein D3 comprises a silicon nitride-containing layer SiN3(14) above C4(12), preferably above and in contact with ZSO4(13).

10. The glazing unit according to claim 1 or 2, wherein D3 comprises a top layer TL(15) containing a metal oxide or metal nitride.

11. The glazing unit according to claim 1 or 2, wherein the absorbent material layers AM1 and AM2 include Nb, Ti, titanium nitride, niobium nitride, an alloy of Ni and Cr, an alloy of Ni, Cr and W, a nitride of an alloy of Ni and Cr, or a nitride of an alloy of Ni, Cr and W.

12. The glazing unit according to claim 1 or 2, wherein AM1 has a geometric thickness in the range of 0.5 to 3.3 nm, and AM2 has a geometric thickness in the range of 0.5 to 5.3 nm.

13. The glazing unit according to claim 1 or 2, wherein the geometric thickness of AM2 is greater than the geometric thickness of AM1, and preferably the ratio of the thickness of AM1 to AM2 is in the range of 0.3 to 0.

9.

14. The glazing unit according to claim 1 or 2, wherein the geometric thickness of D1 is 40 to 68 nm, the geometric thickness of D2 is 65 to 122 nm, and the geometric thickness of D3 is 25 to 44 nm.

15. The glazing unit according to claim 1 or 2, wherein the thickness of D2 is greater than the thicknesses of D1 and D3.

16. The glazing unit according to claim 1 or 2, wherein the ratio of the thickness of D1 to the thickness of D3 is 1.1 to 2.

0.

17. The glazing unit according to claim 1 or 2, wherein the first layer ZSO1, which contains a mixed oxide of zinc and tin, has a thickness of at least 20 nm and a maximum of 60 nm.

18. The layers containing the first and second silicon nitride are made of Si ３ N ４ Si, where the atomic ratio Si / N is in the range of 0.6 to 0.9 ｘ N ｙ The glazing unit according to claim 1 or 2, further comprising a silicon and zirconium mixed nitride having a Si / Zr weight ratio in the range of 70 / 30 to 50 / 50, wherein the silicon nitride-containing layer optionally contains up to 10% by weight of Al.

19. The glazing unit according to claim 1 or 2, wherein the thickness of the first and second silicon nitride-containing layers is at least 21 nm and at most 50 nm.

20. The glazing unit according to claim 1 or 2, wherein the first, second, third, and fourth layers, which contain a mixed oxide of zinc and tin, contain a mixed oxide of zinc and tin, and the weight ratio of zinc to tin, Zn / Sn, is in the range of 1 / 9 to 9 / 1.

21. The glazing unit according to claim 1 or 2, wherein the fourth layer, which contains a mixed oxide of zinc and tin, has a thickness of at least 6 nm and a maximum of 23 nm.

22. The glazing unit according to claim 1 or 2, wherein the top layer TL containing a metal oxide or metal nitride is a layer containing titanium and / or zirconium or a mixed oxide of silicon and zirconium or a mixed nitride of silicon and zirconium.

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