Glazing panel

ES 2 523 932 T3

DESCRIPTION

Glazing

The invention relates to the field of glazing comprising a glass substrate, provided on at least one of its faces with a stack of thin layers.

For environmental reasons and associated with the concern to save energy, homes from now on are provided with multiple, double, even triple glazing, often equipped with layers with low emissivity properties, designed to limit heat transfers to the outside. of the house. These glazings with a very low thermal transmission coefficient are, however, subject to the appearance of water condensation on their outer surface, in the form of mist or frost. In the event of a clear sky at night, the radiation heat exchanges with the sky cause a drop in temperature that is no longer sufficiently compensated by the heat inputs that come from inside the home. When the temperature of the exterior surface of the glazing falls below the dew point, water condenses on the surface, making it difficult to see through the glazing in the morning, sometimes for several hours.

To solve this problem, it is known to arrange on face 1 of the glazing (the outer face) a layer with the property of low emissivity, for example a layer of an electroconductive transparent oxide (TCO) to reduce radiative exchanges with the sky. International patent application WO 2007/115796 recommends, for example, using a stack comprising a TCO layer, a blocking layer and finely a photocatalytic layer.

A solution, if it allows to solve effectively the problems of water condensation to a large extent, is not without drawbacks, however. If the thickness of the layers is not optimized, this solution significantly reduces the solar factor of the glazing. The solar factor corresponds to the fraction of solar energy transmitted by the glazing to the interior of the home, by direct transmission through the glazing and by re-emission of the radiation absorbed by the glazing into the interior. Or, it is important, especially in winter or in cold climates, to be able to maximize the solar heat input through the glazing in order to reduce heating costs.

The invention aims to obviate these drawbacks by proposing a glazing that can limit, even suppress the appearance of condensation (fog or frost) on the external surface, while penalizing the solar factor as little as possible and therefore heat transfers to the interior of the house.

To this end, the object of the invention is a glazing that comprises a glass substrate provided on one of its faces, intended to form the face 1 of said glazing in the position of use, of a stack of thin layers comprising, from said substrate, a transparent electroconductive oxide layer, an intermediate layer with a refractive index in a range from 1.40 to 1.55 and optical thickness Y, and a photocatalytic layer whose optical thickness X is at most 50 nm, said optical thicknesses X and Y, expressed in nanometers, such that:

110. ^^ <κ <135. ^ ° '^8Ύ .

By "face 1" of the glazing, it is understood, as is usual in the art, the external face of the glazing that is intended to be positioned so that it is in contact with the exterior of the dwelling. The faces of a glazing are numbered starting from the outside, although face 2 is the opposite face to face 1, in other words, the other face of the same sheet of glass. In a multiple glazing, comprising two or more panes of glass, face 3 is the face of the second glass pane of the glazing facing face 2, face 4 is the face opposite face 3, and so on.

The refractive indices are measured, for example by ellipsometry, for a wavelength of 550 nm. The optical thickness of a layer corresponds to the product of the physical thickness (also called geometric) of the layer and its refractive index.

The glazing according to the invention is preferably a multiple glazing, especially double or triple, even more, for example quadruple. In fact, these glazings have a low coefficient of thermal transmission and are the most affected by the phenomenon of condensation. A double glazing is generally constituted by two sheets of glass that make the face and that save a sheet of gas, for example air, argon, xenon or even krypton. In general, on the periphery of the glazing, between the glass sheets, a spacer frame, in the form of a metal profile, for example made of aluminum, secured to the glass sheets by a glue, the periphery of the glazing being sealed with the help of Putty, for example made of silicone, polysulfides or polyurethane, to prevent any entry of moisture into the gas sheet. To limit moisture, a molecular sieve is often provided in the spacer frame. A triple glazing is constituted in the same way, with the exception that the number of glass sheets is three.

ES 2 523 932 T3

Although the glazing according to the invention is a triple glazing, at least one other face, chosen from faces 2 to 5, is preferably coated with a stack with low emissivity properties. These may in particular be thin layer stacks comprising at least one layer of silver, the layer or each layer of silver being arranged between the dielectric layers. Low emissivity is understood to mean an emissivity in general of at most 0.1, especially 0.05. Preferably, two other faces, especially faces 2 and 5 are covered with said stack. Other configurations are equally possible, but less preferred: faces 2 and 3, 2 and 4, 3 and 4, 4 and 5, faces 2, 3 and 4, faces 2, 3 and 5, faces 2, 4 and 5, faces 2, 3, 4 and 5. Other types of stacks can be arranged on the faces of the glazing, for example anti-reflective stacks, on face 2, 3, 4, 5 or 6.

Although the glazing according to the invention is a double glazing, face 2 is advantageously coated with a stack with low emissivity properties, especially of the type just described. Alternatively, face 2 can be lined with a solar control stack, which is however not preferred since such a stack leads to a reduction in the solar factor.

The glazing according to the invention can be used like all types of glazing. It can be integrated into a facade, roof, terrace. It can be arranged vertically or inclined.

The glass substrate is preferably transparent and colorless (it is then a clear or extra-clear glass). It can be colored, for example blue, green, gray or bronze, but this embodiment, which is a penalty for the solar factor, is not preferred. The glass is preferably of the silico-sodo-calcium type, but it can also be of the borosilicate or alumino-borosilicate type glass. The thickness of the substrate is generally in a range ranging from 0.5 mm to 19 mm, preferably 0.7 to 9 mm, especially 2 to 8 mm, even 4 to 6 mm. Likewise, when appropriate, for the other glass panes of the multiple glazing.

The glass substrate is preferably of the float type, that is, it can be obtained by a process consisting of pouring the molten glass onto a bath of molten tin ("float" bath). In this case, the stack can also be disassembled both on the "tin" side and on the "atmosphere" side of the substrate. "Atmosphere" and "tin" faces are understood to mean the faces of the substrate that are in contact respectively with the atmosphere prevailing in the float bath and in contact with the molten tin. The tin face contains a small surface amount of tin diffused into the glass framework.

At least one sheet of glass, which consists of the stack that is the object of the invention, can be tempered or hardened, to impart properties of improved mechanical resistance. As described below, thermal tempering can also be used to improve the emissivity or photocatalytic properties of the layers. To improve the acoustic or fracture resistance properties of the glazing according to the invention, at least one glass sheet of the glazing can be laminated to another sheet in the middle of a spacer sheet in a polymer such as polyvinylbutyral (PVB) or polyurethane (PU ).

The transparent electroconductive oxide layer is preferably a fluorine doped tin oxide layer (SnO2: F) or a mixed indium tin oxide (ITO) layer. Other layers are possible, among which thin layers based on mixed indium and zinc oxides (called "IZO"), based on zinc oxide doped with gallium or aluminum, based on titanium oxide doped with niobium, a cadmium or zinc stannate base, antimony doped tin oxide base. In the case of aluminum doped zinc oxide, the doping index (ie the weight of aluminum oxide added to the total weight) is preferably less than 3%. In the case of gallium, the doping index can be higher, typically in a range from 5 to 6%. In the case of ITO, the atomic percentage of Sn is preferably in a range ranging from 5 to 70%, especially from 10 to 60%. For fluorine-doped tin oxide-based layers, the atomic percentage of fluorine is preferably at most 5%, generally 1 to 2%.

These layers have good climatic durability, necessary when the stack is arranged on face 1 of the glazing, which is not the case for other low-emissivity layers, such as silver layers. The latter must imperatively be located on an internal face of the multiple glazing.

ITO is particularly preferred, especially with respect to SnO2: F. With higher electrical conductivity, its thickness can be reduced to obtain the same level of emissivity, which allows minimizing the loss of solar factor. Easily deposited by a sputtering process, especially assisted by a magnetic field, called the "magnetron process", these layers are distinguished by a lower roughness and therefore a lower thickening. During the manufacture, handling and maintenance of glazing, the rougher layers have a tendency indeed to trap various residues, which are particularly difficult to remove.

On the other hand, one of the advantages of fluorine-doped tin oxide is its ease of depositing by chemical vapor deposition (CVD), which, contrary to the sputtering process, does not require subsequent heat treatment and can be carried out on the production line. flat glass by flotation.

The thickness of the TCO layer is adjusted, depending on the nature of the layer, to obtain the desired emissivity, which depends on the anti-condensation embodiments investigated. The emissivity of the TCO layer is preferably

ES 2 523 932 T3 less than or equal to 0.4, especially 0.3. For ITO layers, the geometric thickness will generally be at least 40 nm, even 50 nm and even 70 nm, and often at most 150 nm or 200 nm. For fluorine doped tin oxide layers, the geometric thickness will generally be at least 120 nm, even 200 nm, and often at most 500 nm.

When the glazing is intended to be positioned vertically, the emissivity is preferably at most 0.4, even 0.3. In the case of fluorine doped tin oxide, geometric thicknesses of at least 120 nm, even 200 nm are generally required. In the case of ITO, the geometric thickness will generally be at least 40 nm, even 50 nm, often at most 150 nm.

When the glazing is intended to be located in a sloping position, for example in roofing applications, the emissivity is preferably at most 0.3, even 0.2 and even 0.18. The geometric thicknesses of fluorine doped tin oxide will preferably be at least 300 nm, and those of ITO at least 60 nm, even 70 or 100 nm and often at most 200 nm.

"Emissivity" means normal emissivity at 10 ° C (283 K) in the sense of EN 12898.

The refractive index of the transparent electroconductive oxide layer is preferably in a range from 1.7 to 2.5.

To optimize the effect of the invention, the refractive index of the intermediate layer is preferably at most 1.50, even 1.48.

The intermediate layer is advantageously based on silica, even made up of silica. It is understood that the silica may or may not be stoichiometric. As an example, silica can be doped with aluminum or boron atoms, in order to facilitate its deposition by sputtering processes. In the case of chemical vapor deposition (CVD), silica can be doped by boron or phosphorus atoms, which accelerate deposition. Silica can even be doped with carbon or nitrogen atoms, in contents low enough so that the refractive index of the layer remains in the mentioned ranges. Said intermediate layer also has the advantage of protecting the tCo layer, ensuring better climatic durability as well as better resistance to tempering. In the case of TCO based on fluorine doped tin oxide, the intermediate layer has another advantage of smoothing the surface, reducing the abrasiveness of the layer.

The photocatalytic layer is preferably based on titanium oxide, especially a layer of titanium oxide, in particular in which the refractive index is in a range ranging from 2.0 to 2.5. Titanium oxide is preferably at least partially crystallized in the anatase form, which is the most active phase from the point of view of photocatalysis. The anatase and rutile phase mixtures are also very active. Titanium dioxide can be optionally doped by a metal ion, for example a transition metal ion or by nitrogen, carbon, fluorine atoms, ... Titanium dioxide can also be below stoichiometric or above stoichiometric. If titanium oxide is clearly preferred, other photocatalytic oxides can also be used, among which SrTiO3, ZnO, SiC, GaP, CdS, CdSe, MoS3, SnO2, ZnO, WO3, Fe2O3, BÍ2O3, Nb2O₅, KTaO3, BiVO4, BÍ2WO6.

In the glazing according to the invention, the integrity of the surface of the photocatalytic layer, especially based on titanium oxide, is preferably in contact with the outside, in order to fully apply its self-cleaning function. However, it may be interesting to coat the photocatalytic layer, especially titanium dioxide, with a thin hydrophilic layer, especially based on silica, in order to improve the persistence of hydrophilicity over time.

The optical thickness X of the photocatalytic layer, especially based on titanium oxide, is preferably at most 40 nm, especially 30 nm. Its geometric thickness is advantageously at most 20 nm, even 15 nm, or even 10 nm, and preferably greater than or equal to 5 nm. The very thin layers, although active from a photocatalytic point of view, nevertheless have good self-cleaning, anti-dirt and anti-fog properties. Even for very thin layers, photocatalytic titanium oxide has the particularity, when irradiated by sunlight, of being extremely hydrophilic, with contact angles in water of less than 5 ° and even 1 °, which allows the water to run off more easily, eliminating the dirt deposited on the surface of the layer. In addition, thicker layers have a higher light reflection, which has the effect of reducing the solar factor.

According to a possible embodiment, no layer is arranged between the transparent electroconductive layer and the intermediate layer and / or between the intermediate layer and the photocatalytic layer. Alternatively, a protective layer can be arranged between the TCO layer, especially when it is ITO, and the intermediate layer. This layer, whose thickness is advantageously at most 10 nm, especially 5 nm, even 2 nm, makes it possible to protect the TCO, in particular the ITO, during the deposition of the intermediate layer, especially when the deposition is carried out by sputtering and during eventual subsequent heat treatments. The refractive index of the protective layer is preferably greater than or equal to that of the TCO layer. Silicon nitride is particularly preferred.

ES 2 523 932 T3

A neutralization layer, or stack of layers, can also be arranged between the substrate and the electroconductive transparent oxide layer. In the case of a single layer, its refractive index is preferably comprised between the refractive index of the substrate and the refractive index of said electroconductive transparent oxide layer. Said layers or stacking of layers make it possible to influence the appearance of the glazing reflection, especially its color in reflection. Bluish colors, characterized by negative b * colorimetric coordinates, are preferred. As non-limiting examples, it is possible to use a layer of mixed oxide of silicon and tin (SiSnOx), oxycarbon or oxynitride of silicon, aluminum oxide, mixed oxide of titanium and silicon. A layer stack comprising two layers with high and low index, for example a TiO2 / SiO2, SÍ3N4 / SÍO2 or TCO / SÍO2 stack can also be used (in the latter case, the TCO can be the same as that already used in stacking, or other TCO). The geometric thickness of this layer or of these layers is preferably in a range ranging from 15 to 70 nm. When the transparent electroconductive oxide layer is fluorine doped tin oxide, the neutralization sub-layer is preferably silicon oxycarbide or mixed silicon tin oxide. When the transparent electroconductive oxide layer is ITO, a silicon oxynitride neutralization layer or a stack of Si3NVSiO2 is preferably arranged under this layer.

In particular, when the electroconductive transparent oxide layer is ITO, it is preferable to arrange between the substrate and the neutralization layer or stack an adhesion layer. This layer, which advantageously has a refractive index close to that of the glass substrate, makes it possible to improve the tempering process by favoring the placement of the neutralization layer. The adhesion layer is preferably silica. Its geometric thickness is preferably in a range ranging from 20 to 200 nm, especially from 30 to 150 nm.

The different preferred embodiments described above can of course be combined with each other. Obviously, not all possible combinations are explicitly described in the present text. Some examples of particularly preferred stacks are provided below.

1. Glass / SiOC / SnO2: F / SO / TO

two. Glass / SiSnOx / SnO2: F / SO / TO

3. Glass / (SO) / SiOxNy / ITO / Si3N / SO / TO

Four. Glass / SiO2 / SÍ3N4 / SO / ITO / Si3N / SO / TO

5. Glass / SÍ3N4 / SiO2 / ITO / Si3N / SO / TO

In these stacks, the geometric thickness of the TiO2 layer is advantageously at most 15 nm, even 10 nm. The thickness of the TCO layer is chosen independently, depending on the desired emissivity, as explained later in the present description.

Stacks 1 and 2 use a fluorine doped tin oxide TCO layer. These stacks are preferably obtained by chemical deposition in the vapor phase, generally directly on the waterline of the glass.

Stacks 3 to 5, using ITO, are preferably obtained by magnetron sputtering. Examples 3 and 4 contain on the glass an adhesion layer of silica (optional for example 3), then a neutralization layer of silicon oxynitride or a neutralization stack consisting of a layer of silicon nitride surmounted by a layer of silica, the TCO layer, a silicon nitride protection layer, a silica intermediate layer and finally the titanium dioxide photocatalytic layer. Example 5 corresponds to Example 4, but without the silica bonding layer. The formulas provided do not prejudge the real stoichiometry of the layers, and of a possible doping.

The glazing according to the invention is preferably obtained by a multistage process. The stacking layers are deposited on the glass substrate, which is then generally in the form of a 3.2 * 6 m large sheet of glass.², either directly on the hanging glass tape or just after the floatation process, then the substrate is trimmed to the final dimensions of the glazing. After profiling the edges, the multiple glazing is then manufactured by associating the substrate with other sheets of glass, optionally previously provided with functional coatings, for example of the low-emissivity type.

Different stacking layers can be deposited on the glass substrate by all kinds of thin-layer deposition process. For example, it may be processes of the sol-gel type, pyrolysis (liquid or solid), chemical vapor deposition (CVD), especially plasma-assisted (APCVD), possibly under atmospheric pressure (APPECVD), evaporation.

According to a preferred embodiment, the stacking layers are obtained by chemical deposition in the vapor phase, directly on the production line of the glass sheet by flotation. It is preferably the case when the TCO layer is a fluorine doped tin oxide layer. The deposition is carried out by spraying the precursors through conduits, on the hot glass ribbon. The deposition of different layers can be done at different places on the line: in the flotation chamber, between the flotation chamber and the tempering furnace or in the tempering furnace. The precursors are, in general, oganometallic or halide-type molecules. What

ES 2 523 932 T3 example, there may be mentioned fluorine doped tin oxide, tin tetrachloride, mono-butyltin trichloride (MTBCL), trifluoroacetic acid, hydrofluoric acid. Silicon oxide can be obtained with the aid of silane, tetraethoxysilane (TEOS) or even hexamethyldisiloxane (HDMSO), optionally using an accelerator such as triethyl phosphate. Titanium oxide can be obtained from titanium tetrachloride or titanium isopropoxide. The CVD process, which performs a deposit on hot glass, has the advantage of directly obtaining a TCO layer and a crystallized photocatalytic layer.

According to another preferred embodiment, the stacking layers are obtained by sputtering, in particular assisted by a magnetic field (magnetron method). It is preferably the case when the TCO layer is an ITO layer. In this procedure, a vacuum plasma is created driven into the vicinity of a target comprising the chemical elements to be deposited. The active species of the plasma, which bombards the target, tear off these elements, which are deposited on the substrate formed the desired thin layer. This procedure is called "reactive" when the layer consists of a material resulting from a chemical reaction between the elements removed from the target and the gas contained in the plasma. The main advantage of this procedure resides in the possibility of depositing a very complex stack of layers on the same line by successively running the substrate under different targets, this generally in a single and same device.

However, the magnetron process has a drawback when the substrate is not heated during deposition: the TCO and titanium oxide layers obtained easily crystallize although their respective emissivity and photocatalytic activity properties are not optimized. A heat treatment then becomes necessary.

This heat treatment, intended to improve the crystallization of the TCO and photocatalytic layers, is preferably chosen from the tempering, annealing, and rapid annealing treatments. The improvement in crystallization can be quantified by an increase in the crystallization rate (the mass or volume ratio of crystallized matter) and / or the size of the crystalline grains (or the size of the coherent diffraction intervals measured by diffraction methods. X-ray or Raman spectroscopy). This improvement in crystallization can also be verified indirectly, by improving the properties of the layer. In the case of a TCO type layer, the emissivity decreases, preferably at least 5% in relative terms, even at least 10% or 15%, as well as its light and energy absorption. In the case of layers of titanium dioxide, the improvement in crystallization results in an increase in photocatalytic activity. Activity is generally evaluated by following the degradation of contaminating patterns, such as stearic acid or methylene blue.

The tempering or annealing treatment is generally carried out in a furnace, respectively a tempering or annealing. The entire substrate is brought to an elevated temperature of at least 300 ° C in the case of annealing, and at least 500 ° C, even 600 ° C, in the case of tempering.

Rapid annealing is preferably carried out with the aid of a flame, plasma torch or laser radiation. In this type of procedure, a relative movement is created between the substrate and the device (call, laser, plasma torch). In general, the device is mobile, and the coated substrate parades relative to the device to treat its surface. These procedures make it possible to provide a high energy density to the coating to be treated in a very short time, thus limiting the diffusion of heat towards the substrate and therefore the heating of said substrate. The temperature of the substrate is generally at most 100 ° C, even 50 ° and even 30 ° C during the treatment. Each point of the thin layer is subjected to the fast annealing treatment for a period generally less than or equal to 1 second, even 0.5 seconds.

The rapid annealing heat treatment is preferably carried out with the aid of laser radiation emitting in the infrared or the visible. The wavelength of the radiation is preferably in a range ranging from 530 to 1,200 nm or from 600 to 1,000 nm, especially from 700 to 1,000 nm, even 800 to 1,000 nm. Laser diodes are preferably used, which emit for example at a wavelength of the order of 808 nm, 880 nm, 915 or even 940 nm or 980 nm. In the form of diode systems, very strong powers can be obtained, allowing to achieve surface powers at the level of the coating to be treated greater than 20 kW / cm², even 30 kW / cm².

The laser radiation preferably results from at least one laser beam that forms a line (referred to as a "laser line" in the text that follows) that simultaneously radiates all or part of the width of the substrate. This mode is preferred as it avoids the use of expensive, generally large, and time-consuming displacement systems. In particular, an in-line laser beam can be obtained with the help of high-power laser diode systems associated with a focusing optics. The thickness of the line is preferably between 0.01 and 1 mm. The dimensions of the line are typically between 5 mm and 1 m. The profile of the line can be especially a Gaussian curve or a hollow. The laser line that simultaneously irradiates all or part of the width of the substrate can be made up of a single line (which then radiates the entire width of the substrate) or of several lines, possibly separated. When multiple lines are used, it is preferable that they are arranged so that the entire surface of the stack is treated. The line or each line is preferably arranged perpendicular to the direction of travel of the substrate or is arranged obliquely. The different lines can treat the substrate simultaneously or in a staggered manner in time. The important thing

ES 2 523 932 T3 is that the entire surface to be treated is treated. The substrate can thus be displaced, especially in translational displacement with respect to the fixed laser line, generally below, but eventually above the laser line. This embodiment is particularly noticeable for continuous treatment. Alternatively, the substrate can be fixed and the laser can be mobile. Preferably, the difference between the respective speeds of the substrate and the laser is greater than or equal to 1 meter per minute, even 4 and even 6, 8, 10 or 15 meters per minute, to ensure a high speed of treatment. When the substrate is moving, especially in translation, it can be set in motion with the aid of mechanical transport means, for example with the aid of conveyor belts, rollers, translation platforms. The transport system allows to control and regulate the speed of the movement. The laser can also be set in motion so as to adjust its distance from the substrate, which can be useful in particular when the substrate is pumped, but not only. Indeed, it is preferable that the laser beam is focused on the coating to be treated so that the latter is located at a distance equal to or less than 1 mm from the focal plane. If the substrate or laser displacement system is not sufficiently precise in terms of the distance between the substrate and the focal plane, it is preferable to be able to adjust the distance between the laser and the substrate. This adjustment can be automatic, regulated especially thanks to a measurement of the distance before the treatment.

The laser radiation device can be integrated into a layer deposition line, for example a magnetic field-assisted sputtering deposition line (magnetron method) or a specially assisted chemical vapor deposition (CVD) line. plasma (PECVD), vacuum or atmospheric pressure (APPECVD).

The object of the invention is thus the use of the glazing according to the invention to reduce the appearance of water condensation (especially mist or frost) on the surface of said glazing.

Figure 1 schematically illustrates a section of a part of the glazing according to the invention. Only the stacking arranged on face 1 of the glazing and a part of the glass substrate is shown.

Represented, deposited on substrate 1 (typically glass), are layer 2 of an electrically conductive transparent oxide (typically ITO), intermediate layer 3 (typically SiÜ2) and photocatalytic layer 4 (typically TiO2). The optional layers are the protection layer 5 (typically SÍ3N4), the neutralization layer or stack 6 (typically a SÍ3N4 / SÍO2 stack) and the adhesion layer 7 (for example SiO2).

The following examples illustrate the invention without however limiting it.

Example 1

This example illustrates an embodiment in which the layers are deposited by CVD (chemical vapor deposition), where TCO is fluorine-doped tin oxide (SnO2: F).

Stacks consisting, starting from the substrate, are deposited on a glass substrate by a neutralization layer of silicon oxycarbide (of the generic formula SiOC), refractive index 1.65, a layer of TCO of tin oxide doped with fluorine, refractive index 1.8, an intermediate layer of silica, index 1.48 and finally a photocatalytic layer of TiO2, index 2.0. As in all the text, the refractive indices are given for a wavelength of 550 nm.

The substrate used in the framework of the example is a sheet of clear glass 4 mm thick, marketed under the brand name SGG Planilux® by the applicant.

Table 1 below indicates, for each sample, according to the invention or comparative:

- the geometric thicknesses (in nm) of each of the layers of the stack,

- the energy transmission of the coated substrate of the stack (or direct transmission factor of solar energy), indicated TE, in the sense of standard EN 410: 1.998,

- the colorimetric coordinates a *, b *, in reflection on the side of the stack, calculated taking as reference the D65 illuminator and the CIE-1931 reference observer.

ES 2 523 932 T3

Table 1

<td></td><td>C1</td><td>C2</td><td> 1</td><td> 2</td>

<td>TiO2 (nm)</td><td> 15</td><td> 15</td><td> 15</td><td> 15</td>

<td>SiO2 (nm)</td><td> 20</td><td> 80</td><td> 50</td><td> 50</td>

<td>SnO2: F (nm)</td><td> 300</td><td> 300</td><td> 300</td><td> 300</td>

<td>SiOC (nm)</td><td> 45</td><td> 45</td><td> 45</td><td> 0</td>

<td></td><td></td><td></td><td></td><td></td>

<td>TEA (%)</td><td> 71,5</td><td> 71,9</td><td> 72,8</td><td> 72,5</td>

<td>to*</td><td></td><td></td><td> -0,5</td><td> -11,2</td>

<td>b *</td><td></td><td></td><td> -0,9</td><td> 4,4</td>

Comparative Examples C1 and C2 have an intermediate layer whose thickness is not optimized, unlike Examples 1 and 2 according to the invention.

This translates, for the examples according to the invention, into an energy transmission gain of more than 0.5%, even 1%.

The comparison between Examples 1 and 2 illustrates the effect of the SiOC: Stacking Neutralization Layer of Example 2, which unexpectedly appears less neutral in reflection, yellow-green in color.

A triple glazing is made from substrates C1, C2 and 1. The photocatalytic stack is arranged on face 1 of the glazing, while two silver-based low-emissivity stacks are respectively arranged on faces 2 and 5.

Table 2 below indicates in each case:

- the energy transmission of the glazing (or direct transmission factor of solar energy), indicated TE,

- the glazing solar factor, indicated g.

Table 2

<td></td><td>C1</td><td>C2</td><td> 1</td>

<td>TEA (%)</td><td> 44,9</td><td> 45,3</td><td> 45,8</td>

<td>g (%)</td><td> 52,1</td><td> 52,5</td><td> 53,1</td>

The choice of the thickness of the intermediate layer therefore makes it possible to obtain a very significant gain in the solar factor.

Example 2

This example illustrates an embodiment in which the layers are deposited by sputtering (magnetron method), where TCO ITO (mixed indium tin oxide) is.

Stacks formed, starting from the substrate, of a neutralization stack consisting of a layer of silicon nitride (SiaNL), a refractive index equal to 2.0 after a layer of silica with an index, are deposited in a known manner on a glass substrate. of refraction equal to 1.48, a TCO layer of mixed indium tin oxide (ITO) of refractive index 1.8, an intermediate layer of silica (SO2) with a refractive index of 1.48 and finally a photocatalytic layer of TiO2 whose refractive index is 2.5. The coated substrate in your stack undergoes an annealing step after the layers are deposited. The substrate is the same as that used in the preceding examples.

Table 3 below indicates, for each sample, according to the invention or comparative:

- the geometric thicknesses (in nm) of each of the layers of the stack,

ES 2 523 932 T3

- the energy transmission (or direct transmission factor of solar energy), indicated TE, in the sense of standard EN 410: 1998, of the coated substrate of the stack,

- the colorimetric coordinates a *, b *, in reflection on the side of the stack, calculated taking as reference the D65 illuminator and the CIE-1931 reference observer.

Table 3

<td></td><td>C3</td><td>C4</td><td> 3</td><td> 4</td>

<td>TiO2 (nm)</td><td> 12</td><td> 12</td><td> 12</td><td> 12</td>

<td>SiO2 (nm)</td><td> 10</td><td> 70</td><td> 40</td><td> 40</td>

<td>ITO (nm)</td><td> 100</td><td> 100</td><td> 100</td><td> 100</td>

<td>SiO2 (nm)</td><td> 11</td><td> 11</td><td> 11</td><td> 0</td>

<td>YES3N4 (nm)</td><td> 16,5</td><td> 16,5</td><td> 16,5</td><td> 0</td>

<td></td><td></td><td></td><td></td><td></td>

<td>TEA (%)</td><td> 76,3</td><td> 76,2</td><td> 77,9</td><td> 77,4</td>

<td>to*</td><td></td><td></td><td> -4,4</td><td> 10, 6</td>

<td>b *</td><td></td><td></td><td> -9, 6</td><td> -20, 6</td>

Comparative Examples C3 and C4 have an intermediate layer whose thickness is not optimized, unlike Examples 3 and 4 according to the invention.

This translates, for the examples according to the invention, into an energy transmission gain of at least 1%.

The comparison between examples 3 and 4 illustrates the effect of the neutralization stack SÍ3N4 / SÍO2: stack of example 4, which unexpectedly presents a less neutral in reflection, violet in color.

A triple glazing is made from substrates C3, C4 and 3. The photocatalytic stack is arranged on face 1 of the glazing, while two silver-based low-emissivity stacks are respectively arranged on faces 2 and 5.

Table 4 below indicates in each case:

- the energy transmission of the glazing (or direct transmission factor of solar energy), indicated TE,

- the glazing solar factor, indicated g.

These two quantities are calculated in the sense of the EN 410: 1998 standard.

Table 4

<td></td><td>C3</td><td>C4</td><td> 3</td>

<td>TEA (%)</td><td> 47,3</td><td> 47,2</td><td> 48,2</td>

<td>g (%)</td><td> 56,0</td><td> 55,8</td><td> 57,0</td>

The choice of the thickness of the intermediate stage carried out according to the intention thus makes it possible to obtain a very significant gain in the solar factor, at least 1% in absolute value. The use of ITO also makes it possible to increase the solar factor with respect to fluorine-doped tin oxide, for a comparable level of emissivity (and therefore anti-condensation).

A very thin protective layer of silicon nitride can be placed between the TCO layer and the intermediate layer, without significant effects on the optical and energetic properties of the glazing.

The different glazings exemplified make it possible to greatly reduce the appearance of water condensation, such as mist or frost.