MULTI-GLAZING INCLUDING A SOLAR CONTROL COATING AND AN ANTI-REFLECTIVE COATING

Abstract

Multiple glazing with thermal insulation properties incorporating a first coating (12) with anti-solar properties and a second coating (13) with anti-reflective properties in which said first coating is present on face 2 of said first substrate, and in which said second coating (13) is deposited on face 3 of the second substrate (10) and / or is deposited on face 2 of the first substrate between the glass surface and said first coating.

Description

Title of the invention: MULTIPLE GLAZING COMPRISING A SOLAR-PROOF COATING AND AN ANTI-SOLUTION COATING REFLECTION

[0001] The invention relates to multiple glazings, in particular double glazings or triple glazings for the building sector, said glazing comprising a functional layer of metallic type capable of acting on solar radiation and in particular solar infrared radiation, in particular of wavelength between 780 nm and 5000 nm.

[0002] The invention relates more particularly to multiple glazings with infrared reflection properties, often called in the field anti-solar glazings, and having a low solar factor.

[0003] These glazings are thus intended to equip buildings in particular, in particular with a view to limiting the solar energy input entering them.

[0004] In such multiple glazings, for example double glazing, two glass substrates are kept at a distance by spacers, so as to delimit a cavity filled with an insulating gas which can be air, argon or Krypton. Double glazing is therefore made up of two sheets (substrates) of glass separated by a gas layer. The sequence 4 / 16 / 4 thus designates a double glazing composed of two sheets of glass 4 mm thick and a 16 mm air layer as shown in [Fig.l] attached.

[0005] Conventionally, the faces of a multiple glazing unit are designated from the exterior of the building. For example, a double glazing unit has 4 faces, face 1 being on the exterior of the building (and therefore constitutes the exterior wall of the glazing unit), face 4 on the interior of the building (and therefore constitutes the interior wall of the glazing unit), faces 2 and 3 being on the interior of the double glazing unit.

[0006] In the same way, a triple glazing unit has 6 faces, face 1 is outside the building (outer wall of the glazing unit), face 6 inside the building (inner wall of the glazing unit) and faces 2 to 5 are inside the triple glazing unit, as shown in [Fig.2] attached.

[0007] As is known, thermally insulating double glazing (often also called double glazing (DGU for Double Glazing Unit according to the English term) or triple glazing TGU (for Triple Glazing Unit)) comprises a stack of layers incorporating at least one functional metal layer, i.e. with a property of reflecting solar infrared, in particular at least one functional metal layer based on silver or a metal alloy containing silver, and most often a plurality of such metal layers, for example 2 or 3 silver layers separated by layers of dielectric materials. By infrared reflection property, it is meant that at least a part of the solar infrared radiation, preferably the major part, is reflected by the stack via its functional layer(s), without excluding another part being absorbed by it.

[0008] This stack is conventionally placed on face 2 of the double glazing in such anti-solar glazing for maximum efficiency.

[0009] Examples of multiple glazings equipped with such silver layers are for example described in publications WO 2007 / 101964, EP877005, EP718250, FR2856627, EP 847965, EP 183052, EP226993, EP2920126, EP2766318, EP1441996, EP2432745, EP2424823, EP2332891, EP1730088, EP1663887, EP1606225, EP3041676, US 10556824, EP1458653 or EP3004012.

[0010] Although the functional metal layer(s) is (are) preferably silver-based, other metal layers may also be envisaged without departing from the scope of the invention, in particular based on precious metals such as Au, Pt, or based on Ni, Cr, NiCr, Nb, Ti, the latter being able to be nitrided.

[0011] Currently, such a stack of layers is previously deposited on one of the glass substrates of the multiple glazing in the same installation for depositing layers by magnetic field-assisted cathode sputtering from targets made of the material to be deposited or from a metal target, for example silver, or a constituent element of the layer such as silicon or titanium in a reactive atmosphere of oxygen or nitrogen, to obtain a final layer of a dielectric material such as silicon oxide or silicon nitride. Such a process is called in the field a “magnetron” deposition process.

[0012] A parameter for measuring the quality of multiple glazing with an anti-solar function is the solar factor FS or g factor. It is defined as the ratio between the energy entering the room through the glazing and the incident solar energy. It can be calculated by the sum of the energy flux transmitted directly through the glazing and the energy flux absorbed and then re-emitted towards the interior by the glazing. The FS coefficient (g) can be measured according to standard EN 410 (2011-04).

[0013] Furthermore, in the building industry, glazing is sought with a high level of light transmission (i.e. in the visible range) but which can be variable, in particular from 50 to 85%. In order to be able to compare the performance of different glazings, it is therefore common to also refer to the selectivity of the glazing in question, i.e. its TL / g ratio. Thus, better (greater) selectivity makes it possible to check the good illumination of the room, without heating excessive of it under the effect of incident solar radiation, in particular its infrared portion.

[0014] In countries with high levels of sunshine, it is always necessary to improve the performance of the multiple insulating glazings described above and in particular their selectivity, for the same level of light transmission.

[0015] The object of the present invention is to provide multiple anti-solar glazings comprising a stack of layers incorporating at least one functional metal layer with infrared reflection properties as described above and whose solar factor and consequently selectivity are improved.

[0016] To this end, the present invention relates more particularly to a multiple glazing unit with thermal insulation properties, obtained by the association of at least two glass substrates separated by a gas layer, the front face of the first substrate defining the outer wall of the glazing unit, the successive faces of said two substrates being numbered from 1 to 4 from the outside towards the inside of said glazing unit.The multiple glazing incorporates a) a first coating with infrared reflection properties consisting of a stack of layers preferably comprising at least one silver-based metallic functional layer and b) a second coating with visible light anti-reflection properties consisting of a layer of a material with a refractive index at 550 nm lower than that of the glass or consisting of a stack of layers, including at least one layer of a material with a refractive index at 550 nm lower than that of the glass, preferably lower than 1.4, or even lower than 1.35.

[0017] In the multiple glazing according to the invention, said first coating is present on face 2 of said first substrate and said second coating is deposited on face 3 of the second substrate and / or is deposited on face 2 of the first substrate between the glass surface and said first coating.

[0018] In a novel manner, it has been found that the combination of these two coatings, one having infrared reflection properties and the other anti-reflective properties, makes it possible to offer multiple glazings with improved solar factor and selectivity, for the same target light transmission.

[0019] It is known that the level of reflection of a transparent glass surface is mainly determined by the contrast of the refractive index existing between the surface and that of air (equal to 1). To obtain anti-reflective properties from a reflective surface, it is also known to deposit a transparent layer thereon (here called anti-reflective coating or with anti-reflective property) which provides a specific optical behavior, in which the reflected light waves are in phase opposition with the incident waves when the reflection occurs on the air / coating interface and on the coating / glass interface. This type of coating is called anti-reflective coating single layer.

[0020] By coating with anti-reflective property, we describe here any coating capable of reducing the reflection of visible light (i.e. of wavelength between 380 and 780 nm) on a glass surface, in particular by at least 1%, or even 2%, or even 3% (i.e. of reducing an initial reflection of visible light from 4% to 3, 2 or even 1%).

[0021] The light transmission and reflection on the surface of a glass substrate on which such a coating is deposited can be measured according to standard EN 410 (2011-04).

[0022] There are various possibilities for forming such coatings, in particular porous silica layers. These layers can be nanoporous, mesoporous or even macroporous.

[0023] These coatings are characterized by the presence of a certain amount of air trapped in the porosity. The porosity is created by the imperfect compactness of the nanoparticles, by the elimination of porogens such as PMMA beads present within the silica layer and then eliminated by heating or by acid / alkaline attack. Such coatings are described for example in the following publications: Chen et al., Journal of Sol-Gel Science and Technology 19, 77-82, 2000; Kocs et al. Ceramics International 48 (2022) 4165-4171; Zheng et al., Ceramics International 46 (2020) 18623-18631 or Yoo et al., Vol. 9, No. 11 / 1 November 2019 / Optical Materials Express or patent publications WO2013024226 or EPI 679291.

[0024] There are currently several techniques for having porous layers, in particular through the use of porogens: - Either by using a sacrificial organic porogen which burns on quenching, as indicated previously, - Either by using a “durable” porogen, such as a hollow nanometric bead, in which case heat treatment is not necessary.

[0025] Without departing from the scope of the invention, it is also possible to use other anti-reflective layers than the porous silica type, in particular acrylates crosslinkable under the action of radiation. Preferably, the porosity is not present on the surface for such coatings, the surface is therefore very smooth.

[0026] According to another alternative, it is also possible to use according to the invention an antireflection coating consisting of a stack of layers of different refractive index (generally an alternation of layers of high / low refractive index) in order to obtain a phase shift of the reflected light waves. This type of product is called multilayer or interference antireflection coating. These coatings are generally developed to obtain very high-performance antireflection properties over a wider range of wavelengths. An example is given by the pu- publication WO2012069767.

[0027] By "stack" in the sense of the present invention, it is necessary to understand a set of at least two superimposed layers, from the surface of a glass substrate.

[0028] In particular, for the first infrared-reflecting stack comprising at least one metallic functional layer, stacks leading to a normal emissivity of less than or equal to 0.2, preferably less than or equal to 0.1, more preferably less than or equal to 0.08, or even very advantageously less than or equal to 0.05, within the meaning of standard EN12898 (2001-07) will advantageously be chosen.

[0029] For the purposes of the invention, "in contact" means that no other intermediate layer is interposed between the two layers mentioned.

[0030] According to preferred embodiments of such multiple glazings, which can of course be combined with each other, if necessary: - said second coating consists of a single layer comprising silicon oxide with a refractive index of less than 1.40 at 550 nm, preferably with a refractive index of less than 1.35 at 550 nm, - said layer comprises porous silicon oxide, in particular nanoporous, mesoporous or macroporous, - the physical thickness of said single layer present on face 3 is between 90 nm and 150 nm, - the thickness of said single layer present on face 2 is between 90 nm and 400 nm, - the light transmission of the glazing is between 45 and 85%, preferably between 60 and 80%, - said second coating with anti-reflective properties is deposited on face 3 of the second substrate, - said second coating with anti-reflective properties is deposited on face 2 of the first substrate, between the glass surface and said first coating. - according to a first mode, the glazing comprises only one coating with anti-reflective properties, - according to another embodiment, the glazing comprises a coating with anti-reflective properties deposited on face 3 of the second substrate and a coating with anti-reflective properties deposited on face 2 of the first substrate, between the glass surface and said first coating - other coatings with anti-reflective properties, in particular consisting of so-called interference stacks, can be incorporated on the external faces of the glazing (i.e. on face 1 and / or 4 of a DGU and on faces 1 and 6 of the TGU).

[0031] The invention relates in particular to double glazing obtained by combining two glass substrates separated by a gas layer, in which said first coating is present on face 2 of said first substrate, and in which said second coating is deposited on face 3 of the second substrate and / or is deposited on face 2 of the first substrate between the glass surface and said first coating.

[0032] According to particular and advantageous modes of such double glazing:

[0033] - said first coating is present on face 2 of said first substrate, and a single second coating is deposited on face 3 of the second substrate,

[0034] - said first coating is present on face 2 of said first substrate and a single second coating is deposited on face 2 of the second substrate, between the glass surface and said first coating,

[0035] - said first coating is present on face 2 of said first substrate, a first second coating is deposited on face 3 of the second substrate and a second second coating is deposited on face 2 of the first substrate between the glass surface and said first coating.

[0036] The invention also relates to a triple glazing with thermal insulation properties, obtained by the combination of three glass substrates separated by gas blades, the first substrate delimiting faces 1 and 2 of the glazing, the second substrate delimiting faces 3 and 4 of the glazing, said third substrate delimiting faces 5 and 6 of the glazing, in which said first coating is present on face 2 of said first substrate, and in which said second coating and / or is deposited on face 3 of the second substrate, on face 4 of the second substrate and / or is deposited on face 2 of the first substrate between the glass surface and said first coating.

[0037] According to particular and advantageous modes of such triple glazing:

[0038] - a single second coating is deposited on face 3 of the second substrate and / or is deposited on face 2 of the first substrate between the glass surface and said first coating,

[0039] - a first second coating is deposited on face 3 of the second substrate and a second second coating is deposited on face 2 of the first substrate between the glass surface and said first coating,

[0040] - a first second coating is deposited on face 3 of the second substrate and a second second coating is deposited on face 4 of said second substrate.

[0041] The details and advantageous characteristics of the invention emerge from the following non-limiting examples, illustrated using the attached figures which schematically show different embodiments of multiple glazings according to the present invention: - [Fig.l] describes double glazing according to a first embodiment of the invention, - [Fig.2] describes triple glazing according to a second embodiment of the invention.

[0042] In these figures, the actual dimensions and proportions of the various constituent elements of the glazing are obviously not respected in order to facilitate their reading.

[0043] [Fig.l] represents a double glazing unit 100 (DGU) of conventional design consisting of two sheets of glass, each constituting a glass substrate 10, 30. The two substrates are separated, held together and facing each other by spacers 21 and frames 20, the assembly delimiting a closed space filled by an intermediate gas layer 15. According to the invention, the gas can be air, argon or Krypton (or a mixture of these gases).

[0044] The first glass sheet (substrate 30) faces outwards when considering the incident direction of the sunlight entering the building, illustrated by the arrow oriented in the figure from left to right. Its front face 29 (called “face 1”), which also constitutes the outer wall of the double glazing 100, may be bare or alternatively be coated with another coating of the self-cleaning type as described in publication EP 850204 or of the anti-condensation type, as described in publications WO2007 / 115796 or WO2009 / 106864.

[0045] The substrate 30 is coated on its rear face 31 (face 2 of the DGU), facing the intermediate gas blade 15, with a coating 12 called antisolar because it reflects a major part of the infrared portion of the incident radiation, in particular from 780 nanometers to 5000 nanometers. This stack is of the type described previously, and preferably comprises at least one layer of silver, preferably two or three layers of silver.

[0046] The other glass sheet, oriented furthest inside the building when considering the incident direction of the sunlight entering it, constitutes the second substrate 10. According to the invention and as shown in [Fig. 1], this substrate 10 is coated on its front face 9 (face 3 of the DGU), facing the intermediate gas blade, with an antireflection coating 13 of the type previously described and in particular consisting of a layer of porous silicon oxide, with a refractive index at 550 nm lower than that of the glass, in particular of the order of 1.33. In [Fig. 1], the antireflection coating 13 is shown on face 3 of the DGU but according to the invention it is also possible to arrange it on face 2 of the DGU, in particular between the surface 31 of the substrate 30 and the antisolar stack 12.

[0047] According to another embodiment of the present invention, it is advantageous to arrange two coatings with an anti-sun function in the manner previously described respectively on the faces 2 and 3 of the DGU, as described in the examples which follow.

[0048] [Fig.2] this time represents a triple glazing 101 (TGU) of classic design consisting of three sheets of glass, each constituting a glass substrate 30, 10 and 40. Identical numbers are taken from [Fig.l] to illustrate the same constituent elements.

[0049] As previously, the substrate 30 is coated on its rear face 31 (face 2 of the DGU), facing the intermediate gas blade 15, with a coating 12 called antisolar.

[0050] According to an embodiment of the invention illustrated by [Fig. 2], the intermediate glass sheet 10 is coated on its front face 9 (face 3 of the DGU), facing the intermediate gas blade, with an antireflection coating 13 of the type previously described and in particular consisting of a layer of porous silicon oxide. Another antireflection coating 13' can also be deposited on the other face 11 of the intermediate substrate 10 (i.e. on face 4) of the TGU. According to the invention it is also possible to place this on face 2 of the TGU, in particular between the surface 31 of the substrate 30 and the antisolar stack 12, or even on faces 2 and 4 of the DGU or 3 and 4 of the TGU.

[0051] The invention and its advantages will be better understood upon reading the following non-limiting examples.

[0052] In all the examples below, the stacks of thin layers with low-emissivity properties are deposited on clear soda-lime glass substrates, marketed under the reference PLANICLEAR® by the applicant company.

[0053] For all the examples below, for double-glazed or triple-glazed assemblies, the stacks of thin layers were positioned respectively on face 2 and / or 3, the numbering increasing from the glass substrate furthest to the outside of the building when considering the incident direction of the sunlight entering the building, face 1 therefore corresponding to the glass surface facing the outside of the glazing. The double and triple glazings described in the examples below are in accordance with Figures 1 and 2 attached.

[0054] The double glazing units (or DGU for Double Glazing Unit) assembled according to the examples have the configuration: 4-16-(Ar 90%)-4, that is to say they are made up of two transparent 4 mm Planiclear® glass sheets separated by an intermediate gas layer comprising 90% argon and 10% air by volume, with a thickness of 16 mm, the whole being held together by a frame structure 20 and spacers 21.

[0055] The triple glazing units (or TGU or DGU for Double Glazing Unit) assembled according to the examples have the configuration: 4-16-(Ar 90%)-4-16-(Ar 90%)-4.

[0056] Table 1 below summarizes the general conditions for magnetron sputtering deposition to obtain the different layers used in the anti-solar stacks of the examples:

[0057] [Tables 1] Target Layer Used Deposition Pressure Gas Si3N4 Si:Al at 92:8 wt% 1.5.10 3 mbar Ar / (Ar + N2) at 45% TiO2 TiOx with x of the order of 1.9 1.5.10 3 mbar Ar / (Ar + O2) at 95% SnZnO SnZn:Sb at 34:65:1 wt% 2.103 mbar Ar / (Ar + O2) at 58% ZnO Zn:Al at 98:2 wt% 2.103 mbar Ar / (Ar + O2) at 52% Ti Metallic Ti 2.103 mbar Ar at 100% Ag Ag 4.103 mbar Ar at 100% SiO2 Si:Al at 92:8 wt% 2.103 mbar Ar / (Ar + O2) at 70%

[0058] The anti-reflective coating consists of a single layer based on porous silicon oxide, the porosity of which is adjusted to obtain a layer of material with a refractive index of 1.33 at 550 nm. Example 1:

[0059] In this first series of examples, we compare DGU double glazing units with a target light transmission of 68.5%.

[0060] The double glazing has a 4 / 16 / 4 configuration as described previously.

[0061] This first example illustrates the case of a combination of an anti-solar coating deposited on face 2 by magnetron sputtering and the porous silica anti-reflective layer described previously (index 1.33) on face 2 or on face 3 or on both faces.

[0062] More precisely, the glazing according to example 1a is a reference glazing having a light transmission of 68.5% and comprising on its face 2 an antisolar stack comprising two functional silver layers and the complete structure of which is described in table 3 below.

[0063] In example 1b, an anti-reflective monolayer of porous silica is positioned on face 2 of the DGU, between the glass surface and the anti-solar stack, with a thickness of 115 nm and a refractive index of 1.33 at 550 nm.

[0064] The anti-solar stack is then adjusted to obtain a light transmission of 68.5% (in particular by modifying the thicknesses of the silver layers), as described in Table 3 below.

[0065] In example 1, two anti-reflective layers of the same index as previously are positioned on faces 2 and 3 of the DGU, with thicknesses of 103.5 nm and 100 nm respectively. The anti-solar stack (in particular the thicknesses of the silver layers) is then adjusted to obtain a final light transmission of 68.5% respectively.

[0066] The results are reported in Table 2 below:

[0067] [Tables2] Ex. la Ex.lb Ex. le Solar factor (g) 36.4 34.5 33.8 Selectivity 1.88 1.98 2.01 tl 68.5 68.5 68.5 a*T -4.8 -4.8 -4.5 b*T 0.6 0.9 2.1 te 34.8 33.0 33.0 RLext 16.0 16.0 16.0 RLint 15.0 15.0 14.7

[0068] In the previous table, TL is the light transmission, a*T and b*T are the colorimetric coordinates in the international Lab system, TE is the energy transmission and RLext and RLint are the light reflections respectively on the exterior and interior sides of the double glazing.

[0069] The thicknesses in nanometers of the different layers constituting the antisolar stacks for examples 1a to 1c are given in table 3 below (the one furthest from the surface of the glass substrate being referenced first):

[0070] [Tables3] Ex. la Ex.lb Ex. SnZnO 1.0 1.0 1.0 Si3N4 32.8 31.1 30.9 SnZnO 5.0 5.0 5.0 ZnO 5.0 5.0 5.0 Ti 0.4 0.4 0.4 Ag 15.5 16.8 17.0 ZnO 5.0 5.0 5.0 Si3N4 82.2 84.1 85.4 ZnO 5.0 5.0 5.0 Ti 0.6 0.6 0.4 Ag 15.5 17.3 18.2 ZnO 5.0 5.0 5.0 TiO2 19.2 20.9 21.5

[0071] It can be seen by comparing the above examples that the selectivity obtained in the case of an anti-solar stack deposited on face 2 is significantly improved by the addition of an anti-reflective layer on face 2 and / or face 3 of the double glazing.

[0072] In particular, the deposition of the antireflection layer on face 2 and / or 3 and the adjustment accordingly of the structure of the antisolar stack results in a significant reduction in the solar factor g and consequently in a significant improvement in the selectivity. It is observed for example that, for the same TL of 68.5%, the addition of the antireflection layer on face 2 and the adjustment of the antisolar stack results in a reduction of 5.2% in the factor g (comparison of examples 1a and 1b). The gain can be even more significant (reduction of g by 7.1%) if two antireflection stacks, on faces 2 and 3, are combined with the antisolar stack within the DGU (comparison of examples 2a and 2c). Example 2:

[0073] In this second series of examples, we compare DGU double glazing units with a target light transmission of 77%.

[0074] Like the previous one, this example illustrates the case of a combination of an anti-solar coating deposited on face 2 by magnetron sputtering and the anti-reflective layer described previously (index 1.33) on face 2 or on face 3 or on both faces.

[0075] More precisely, the glazing according to example 2a is a reference glazing having a higher light transmission equal to 77% and comprising on its face 2 an antisolar stack comprising two functional silver layers and the complete structure of which is described in table 5 below.

[0076] In example 2b, an anti-reflective monolayer of porous silica is positioned directly on face 3 of the DGU, with a thickness of 106 nm and a refractive index of 1.33 at 550 nm.

[0077] In example 2c, two anti-reflective layers of the same index as previously are positioned on faces 2 and 3 of the DGU, with thicknesses of 103.5 nm and 100 nm respectively. The anti-solar stack (in particular the thicknesses of the silver layers) is then adjusted to obtain a final transmission of 77.0% respectively.

[0078] The results are reported in Table 4 below:

[0079] [Tables4] Ex.2a Ex.2b Ex.2c Solar factor (g) 45.9 42.5 40.7 Selectivity 1.68 1.81 1.89 tl 77.0 77.0 77.0 a*T -3.3 -3.1 -4.0 b*T 0.7 0.8 0.5 te 43.9 40.7 39.0 RLext 10.8 10.3 9.9 RLint 11.3 10.4 9.9

[0080] The thicknesses in nanometers of the different layers constituting the antisolar stacks for examples 2a to 2c are given in table 5 below (the furthest from the surface of the glass substrate being referenced first):

[0081] [Tables5] Ex.2a Ex.2b Ex.2c SnZnO 1.0 1.0 1.0 Si3N4 33.0 29.4 32.3 SnZnO 5.0 5.0 5.0 ZnO 5.0 5.0 5.0 Ti 0.4 0.4 0.4 Ag 15.1 17.3 15.5 ZnO 5.0 5.0 5.0 Si3N4 84.2 83.2 81.3 ZnO 5.0 5.0 5.0 Ti 0.6 0.2 0.2 Ag 9.4 11.3 14.7 ZnO 5.0 5.0 5.0 TiO2 25.1 23.9 21.5

[0082] It can be seen by comparing the above examples that the selectivity obtained in the case of an anti-solar stack deposited on face 2 is significantly improved by the addition of an anti-reflective layer on face 2 and / or face 3 of the double glazing.

[0083] In particular, the deposition of the antireflection layer on face 2 and / or 3 and the adjustment accordingly of the structure of the antisolar stack results in a significant reduction in the solar factor g and consequently in a significant improvement in the selectivity. It is observed for example that, for the same TL of 77%, the addition of the antireflection layer on face 3 and the adjustment of the antisolar stack results in a reduction of 7.4% in the factor g (comparison of examples 2a and 2b). The gain can be even more significant (reduction of g by 11.3%) if two antireflection stacks, on faces 2 and 3, are combined with the antisolar stack within the DGU (comparison of examples 2a and 2c). Example 3:

[0084] In this third series of examples, TGU triple glazing units are described having a target light transmission of 68.5%. The triple glazing units have a 4 / 16 / 4 / 16 / 4 configuration as described previously.

[0085] More precisely, the glazing according to example 3a is a reference TGU comprising on its face 2 an antisolar stack comprising two functional silver layers and the complete structure of which is described in table 7 below.

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092] In example 3b, a 95 nm thick anti-reflective layer of porous silica with a refractive index of 1.33 is additionally positioned on face 3 of the TGU. The stack (in particular the thicknesses of the silver layers) is then adjusted to obtain the target light transmission of 68.5%. In example 3c, the two anti-reflective layers of porous silica with a refractive index of 1.33 are positioned on faces 2 and 3 of the TGU, respectively, with respective thicknesses of 332 nm and 99 nm. The anti-solar stack (especially the thicknesses of the silver layers) is adjusted to achieve a final target light transmission of 68.5. The results are reported in Table 6 below: Ex.3a Ex. 3b Ex.3c Solar factor (g) 39.5 37.9 35.7 Selectivity 1.73 1.81 1.92 tl 68.5 68.5 68.5 a*T -3.6 -5.0 -5.0 b*T -0.5 0.7 -4.8 te 37.0 35.6 1.5 RLext 16.0 16.0 16.0 RLint 18.3 17.1 17.5 The thicknesses in nanometers of the different layers constituting the antisolar stacks for examples 3a to 3c are given in table 7 below (the one furthest from the surface of the glass substrate being referenced first): Ex.3a Ex. 3b Ex.3c SnZnO 1.0 1.0 1.0 Si3N4 30.8 33.5 29.1 SnZnO 5.0 5.0 5.0 ZnO 5.0 5.0 5.0 Ti 0.5 0.4 0.4 Ag 15.3 14.8 16.9 ZnO 5.0 5.0 5.0 Si3N4 80.1 82.2 82.3 ZnO 5.0 5.0 5.0 Ti 0.2 0.4 0.2 Ag 11.7 14.1 15.3 ZnO 5.0 5.0 5.0 TiO2 20.3 20.7 21.5

[0093] 4* / 16 / 4

[0094] It is also observed that, for the same TL of 68.5%, the addition of the antireflection layer on face 3 and the adjustment of the antisolar stack results in a 5% reduction in the g factor (comparison of examples 2a and 2b). The gain can be even more significant (9.5% reduction in g) if two antireflection stacks, respectively on faces 2 and 3, are combined with the antisolar stack within the TGU (comparison of examples 3a and 3c).

Claims

Claims

1. Multiple glazing with thermal insulation properties, obtained by combining at least two glass substrates (10, 30) separated by a gas layer (15), the front face (29) of the first substrate (30) defining the outer wall of the glazing, the successive faces of said two substrates being numbered from 1 to 4 from the outside to the inside of said glazing, said multiple glazing incorporating: - a first coating (12) with infrared reflection properties consisting of a stack of layers, said stack preferably comprising at least one silver-based metal layer, - a second coating (13) with anti-reflective properties consisting of a layer of a material with a refractive index at 550 nm lower than that of the glass or consisting of a stack of layers, including at least one layer of a material with a refractive index at 550 nm lower than that of the glass,wherein said first coating is present on face 2 of said first substrate, and wherein said second coating (13) is deposited on face 3 of the second substrate (10) and / or is deposited on face 2 of the first substrate, between the glass surface and said first coating.,

2. Multiple glazing according to claim 1, wherein said second coating consists of a single layer comprising silicon oxide with a refractive index of less than 1.40 at 550 nm, preferably with a refractive index of less than 1.35 at 550 nm.

3. Multiple glazing according to the preceding claim, wherein said layer comprises porous silicon oxide, in particular nanoporous, mesoporous or macroporous.

4. Multiple glazing according to one of the preceding claims in which the physical thickness of said single layer present on face 3 is between 90 nm and 150 nm.

5. Multiple glazing according to one of the preceding claims in which the thickness of said single layer present on face 2 is between 90 nm and 400 nm.

6. Multiple glazing according to one of the preceding claims, in which the light transmission is between 45 and 85%, preferably between 60 and 80%.

7. Multiple glazing according to one of the preceding claims, in which said second coating with anti-reflective properties is deposited on face 3 of the second substrate.

8. Multiple glazing according to one of the preceding claims, in which said second coating with anti-reflective properties is deposited on face 2 of the first substrate, between the glass surface and said first coating.

9. Multiple glazing according to one of the preceding claims, comprising only one coating with anti-reflective properties.

10. Multiple glazing according to one of claims 1 to 8, in which a coating with anti-reflective properties is deposited on face 3 of the second substrate and a coating with anti-reflective properties is deposited on face 2 of the first substrate, between the glass surface and said first coating.

11. Double glazing according to one of the preceding claims, obtained by the association of two glass substrates (10, 30) separated by a gas blade (15), in which said first coating is present on face 2 of said first substrate, and in which said second coating (13) is deposited on face 3 of the second substrate (10) and / or is deposited on face 2 of the first substrate between the glass surface and said first coating.

12. Double glazing according to the preceding claim, in which said first coating is present on face 2 of said first substrate (30), and in which a single second coating (13) is deposited on face 3 of the second substrate (10).

13. Double glazing according to claim 11, wherein said first coating is present on face 2 of said first substrate (30) and wherein a single second coating (13) is deposited on face 2 of the second substrate (10), between the glass surface and said first coating.

14. Double glazing according to claim 11, wherein said first coating is present on face 2 of said first substrate, and wherein a first second coating (13) is deposited on face 3 of the second substrate (10) and wherein a second second coating (13) is deposited on face 2 of the first substrate between the glass surface and said first coating.

15. Triple glazing with thermal insulation properties according to one of the claims- dications 1 to 10, obtained by the association of three glass substrates separated by gas blades, the first substrate delimiting faces 1 and 2 of the glazing, the second substrate delimiting faces 3 and 4 of the glazing, said third substrate delimiting faces 5 and 6 of the glazing, in which said first coating is present on face 2 of said first substrate, and in which said second coating (13) and / or is deposited on face 3 of the second substrate (10), on face 4 of the second substrate and / or is deposited on face 2 of the first substrate between the glass surface and said first coating.

16. Triple glazing according to one of the preceding claims, in which a single second coating (13) is deposited on face 3 of the second substrate (10) and / or is deposited on face 2 of the first substrate between the glass surface and said first coating.

17. Triple glazing according to claim 15, wherein a first second coating (13) is deposited on face 3 of the second substrate (10) and wherein a second second coating (13') is deposited on face 2 of the first substrate between the glass surface and said first coating.

18. Triple glazing according to claim 15, wherein a first second coating (13) is deposited on face 3 of the second substrate (10) and wherein a second second coating (13') is deposited on face 4 of said second substrate (10).

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