WO2021053125A1

WO2021053125A1 - Insulating glass panel comprising a thin chromium-based layer

Info

Publication number: WO2021053125A1
Application number: PCT/EP2020/076064
Authority: WO
Inventors: Rosiana Aguiar; Sacha ABADIE
Original assignee: Saint-Gobain Glass France
Priority date: 2019-09-20
Filing date: 2020-09-18
Publication date: 2021-03-25
Also published as: MX2022003313A; EP4031506A1; CN114391005A; FR3101077A1; FR3101077B1; CO2022001910A2; BR112022000923A2; AU2020349035A1

Abstract

A transparent glass article comprising at least one glass substrate, at least one of the faces of which is provided with a coating formed by a stack of thin layers, including at least one functional layer providing the article with solar control properties, said coating comprising the following series of layers, with reference to the surface of said substrate: - a first layer comprising silicon nitride; - a functional metal chromium-based layer with a physical thickness that is greater than or equal to 1 nm and less than or equal to 9 nm; - a second layer comprising silicon nitride, wherein said first and second layers comprising silicon nitride are directly in contact with the functional metal chromium-based layer.

Description

DESCRIPTION

TITLE

Insulating glazing comprising a thin chromium-based layer The invention relates to so-called solar control insulating glazing, provided with stacks of thin layers, at least one of which is functional, that is to say that it acts on solar and / or thermal radiation mainly by reflection and / or absorption of near infrared (solar) or far (thermal) radiation. The present invention relates more particularly to glazing with layer (s), in particular those intended mainly for the thermal insulation of buildings.

The term “functional” or even “active” layer (s), within the meaning of the present application, is understood to mean the layer (s) of the stack which gives the stack the essential of its thermal properties. Most often, the thin film stacks fitted to the glazing give it improved solar control properties, essentially through the intrinsic properties of this active layer. Said layer acts on the flow of solar radiation passing through said glazing, as opposed to the other layers, generally made of dielectric material and their function essentially being chemical or mechanical protection of said functional layer or adjustment of the color.

Such glazing provided with stacks of thin layers act on the incident solar radiation either primarily by absorption of incident radiation by the functional layer, or primarily by reflection by this same layer.

They are grouped together under the designation of solar control glazing. They are marketed and used mainly:

- either to essentially protect the home from solar radiation and prevent overheating, such glazing being qualified in the insulation business,

- or mainly to provide thermal insulation of the home and prevent heat loss, this glazing being referred to as insulating glazing.

For the purposes of the present invention, the term “sunscreen” therefore means the ability of the glazing to limit the energy flow, in particular solar infrared radiation (1RS) passing through it from the outside to the inside of the dwelling or the passenger compartment. . To measure the energy insulating properties of glazing, the solar factor denoted FS or g in the field is used in the field.

In a known manner, the solar factor g is equal to the ratio of the energy passing through the glazing (that is to say entering the room) and the incident solar energy. More particularly, it corresponds to the sum of the flux transmitted directly through the glazing and of the flux absorbed by the glazing (including the stacks of layers possibly present on one of its surfaces) then possibly re-emitted towards the interior (the local).

Good thermal insulation properties thus firstly require a low resistivity of the functional layer. Such a property, however, also results in greater light absorption, which tends to significantly reduce the light transmission within the glazing. The object of the present invention is first of all to provide a glazing provided with a stack exhibiting a good compromise between its light transmission and its thermal insulation properties.

In general, all the light characteristics presented in the present description, in particular, the light transmission TL and the light reflection RL, as well as the factor g, are obtained according to the principles and methods described in standard NF EN 410 ( 2011) relating to the determination of the luminous and energetic characteristics of glazing used in glass for construction.

Ideally, such glazing should exhibit a substantially neutral coloration both in transmission and in reflection, whether on the face of the glazing on which the stack is deposited (interior side) or on the opposite face (exterior side).

The most efficient stacks marketed at the present time incorporate at least one metallic layer of the silver type operating essentially in the mode of the reflection of a major part of the incident IR (infrared) radiation. These stacks are thus used mainly as glazing of the low-emissive type (or low-e in English) for the thermal insulation of buildings. These layers are however very sensitive to humidity and are therefore exclusively used in double glazing, on face 2 or 3 thereof, in order to be protected from humidity. It is thus not possible to deposit such layers on single glazing (also called monolithic). The stacks according to the invention do not include such layers based on silver, or else based on gold or of platinum, or else in very negligible quantities, in particular in the form of inevitable impurities.

Likewise, the functional layers, or even the stacks, of the glass articles according to the invention are free from nickel or copper.

The disadvantage of silver-based layers is also their low mechanical resistance, which also explains their use almost exclusively in the building sector on the interior faces of multiple glazing (for example faces 2 and 3 of a double glazing).

Other metallic layers with a sunscreen function have also been reported in the field, comprising functional layers of the metallic Nb or nitrided NbN type, as described for example in application W001 / 21540 or else in application WO2009 / 112759. Within such layers, the solar radiation is this time mainly absorbed in a non-selective manner by the functional layer comprising niobium, the IR radiation (that is to say, the wavelength of which is between approximately 780 nm and 2500 nm) and visible radiation (whose wavelength is between approximately and 380 and 780 nm) being absorbed indiscriminately by the active layer.

In addition to sun protection properties, in the building sector or even in the automobile sector, private glazing is sometimes sought after, that is to say glazing allowing easy daytime vision from the inside to the outside. occupants of a room, a building or a vehicle, but presenting from the outside to the inside a mirror appearance preventing vision in this direction. However, in night vision, that is to say when the external luminosity is greater than the internal luminosity, such glazing may have the disadvantage of exhibiting this same mirror effect this time from the outside to the inside if the inner thinking is too important.

To solve such a problem, it is necessary to provide glass articles whose light characteristics are suitable.

In particular, the problem described above could be solved according to the invention thanks to the development of glass articles in which: the light transmission is greater than or equal to 20%, the light reflection on the glass side (outer face) Ri_ext is greater or equal to 25%, or even greater than or equal to 30%, the light reflection on the stacking side (inner face) Runt is less than or equal to 20%, or even less than or equal to 15%, the difference between the two light reflections Ri_ext - Runt (also noted ARL in the rest of the description) is greater than 15% or even greater than 18%, or even greater than 20%.

By stack side is meant the face of the glazing on which the stack is deposited. By glass side is meant the face of the glazing opposite to that on which the stack is deposited, in principle not covered. For the purposes of the present invention, the terms “exterior face” (or “exterior”) and “interior face” or (“interior”) refer to the position of the glazing when it is fitted to the building or the vehicle that it is equipped with. team.

Also, the glass and glazing articles according to the invention have energy insulation properties in accordance with those required in the field, in particular a solar factor g close to and preferably less than 50%, or even less than 45% or even less. at 40% in some configurations.

The object of the present invention is to provide a glass article making it possible to solve the technical problems described above.

More specifically, the present invention relates to a transparent glass article, comprising at least one glass substrate provided on at least one of its faces with a coating consisting of a stack of thin layers, at least one of which is functional layer giving said article solar control properties, said coating comprising the succession of the following layers, with reference to the surface of said substrate: a first layer comprising silicon nitride, a functional layer based on metallic chromium, with a physical thickness greater than or equal to 1 nm and less than or equal to 9 nm, preferably greater than or equal to 2 nm and less than or equal to 8 nm. a second layer comprising silicon nitride, in which said first and second layers comprising silicon nitride are directly in contact with the functional layer based on metallic chromium.

According to particular and preferred embodiments of the present invention, which can be combined with one another if necessary: - The first layer comprising silicon nitride has a thickness between 1 and 100 nm, preferably between 10 and 80 nm.

- The second layer comprising silicon nitride has a thickness between 1 and 100 nm, preferably between 1 and 50 nm, more preferably between 2 and 25 nm.

- The first layer comprising silicon nitride is thicker than the second layer comprising silicon nitride.

- The stack does not include layers based on Ag, Au, Pt, Cu, Ni or stainless steel.

- The stack comprises a single functional layer based on metallic chromium, the thickness of the layer being between 2 and 9 nm, in particular between 3 and 8 nm.

- The stack is formed by the succession of the following layers:

SiN _x / Cr / SiN _x in which SiN _x denotes said layer comprising silicon nitride and Cr denotes said layer based on metallic chromium.

- The stack comprises two functional layers based on chromium, a third layer comprising silicon nitride being interposed in the stack between the two functional layers based on chromium.

- The third chromium layer is directly in contact with the chromium-based layers, according to the following succession of layers:

SiN _x / Cr / SiN _x / Cr / SiN _x in which SiN _x denotes said layers comprising silicon nitride and Cr denotes said layers based on metallic chromium.

In particular, the value of x may deviate from the conventional value corresponding to the defined compound S13N4 (x = 1.33), in the sense of an over-stoichiometry in nitrogen or preferably of a substoichiometry in nitrogen, even if in principle it does not differ by more than 20% from this theoretical value.

- The functional layer or layers based on chromium comprise more than 80 atomic% of chromium.

- The functional layer or layers consist essentially of chromium and preferably consist of chromium, apart from inevitable impurities.

- The first layer comprising silicon nitride is deposited directly on the glass substrate and is in contact with the latter. - At least one layer comprising a metal oxide is present between the surface of the glass substrate and the first layer comprising silicon nitride, the metal oxide preferably being chosen from an oxide of an element chosen from silicon, titanium, tin, zinc, aluminum, zirconium or a mixture of at least two of these elements, in particular silicon oxide, titanium oxide or an oxide of zinc and tin.

- At least one layer comprising a metal oxide is present above said succession of layers, the metal oxide preferably being chosen from an oxide of an element chosen from silicon, titanium, tin, zinc, aluminum or a mixture of at least two of these elements, in particular silicon oxide, titanium oxide, zirconium oxide or a mixture of these oxides.

- The article is thermally hardened and / or curved.

The functional layer or layers based on chromium comprise at least 50 atomic% of chromium. Preferably, the functional layer or layers of the stack have at least 70 atomic%, or even at least 80 atomic% of chromium, or even preferably more than 90 atomic% of chromium.

According to a very preferred embodiment, the functional layer or layers consist essentially of chromium and more preferably still consist of chromium, apart from inevitable impurities.

Without departing from the invention, however, the functional layer or layers may comprise one or more other atoms, for example chosen from Al, Si, Mo, W, Zn, Ti, Mg, Co, Ni.

The chromium content and that of the other elements possibly present can be measured according to any known technique. As an example, we can cite XPS (X photoelectron spectrometry),

The functional layer (s) according to the invention may comprise a minimal part of nitrogen and / or oxygen, but less than 15 atomic%, or even less than 10 atomic%, or even less than 5 atomic%. Preferably, however, the functional layer (s) according to the invention do not in principle comprise nitrogen or oxygen or else in the form of inevitable impurities, resulting for example from a heat treatment of the glazing such as tempering or bending. . Likewise, the functional layer or layers according to the invention do not in principle comprise carbon or hydrogen or else in the form of inevitable impurities. In the layers according to the invention comprising silicon nitride, the silicon nitride preferably represents at least 50% by weight of silicon nitride, on the basis of an S1 ₃ N ₄ formulation, and preferably more than 80% of silicon nitride or even more than 90% silicon nitride, based on the S1 ₃ N ₄ formulation. Said layers preferably consist essentially of silicon nitride, but can also comprise an element other than silicon, in particular aluminum. Aluminum is commonly used in particular, in proportions of up to 15 atomic%, in silicon targets used for the deposition by cathodic sputtering assisted by a magnetic field (magnetron) of stacks of thin layers on control glazing. solar, and in particular layers based on silicon nitride. Thus, without departing from the scope of the invention, the silicon of said layers can be substituted by elements of the Al, Zr, B, etc. type, in particular so as to modify the color in transmission and / or in reflection of the glazing, according to techniques well known in the art and in proportions which can range up to 15 atomic%.

The coatings according to the invention are conventionally deposited by deposition techniques of the vacuum sputtering type assisted by a magnetic field of a cathode of the material or of a precursor of the material to be deposited, often called the magnetron sputtering technique in the field. Such a technique is conventionally used today, in particular when the coating to be deposited consists of a more complex stack of successive layers of thicknesses of a few nanometers or a few tens of nanometers.

The present invention also relates to a front facing panel of the spandrel type incorporating at least one glazing as described above or to a side window, a rear window or a roof for an automobile or other vehicle constituted by or incorporating said glazing.

According to the invention, the functional layers according to the invention make it possible to obtain a relatively high value of the light transmission of the substrate, while retaining a notable insulating effect, despite the very low thickness of the functional layer, after a heat treatment. .

By the terms “sublayer and“ overlayer ”, reference is made in the present description to the respective position of said layers with respect to the layer (s). functional in the stack, said stack being supported by the glass substrate taken as a reference.

In particular, the sublayer is generally the layer in contact with the glass substrate and the overlayer is the outermost layer of the stack, facing away from the substrate.

If the application more particularly targeted by the invention is glazing for buildings, it is clear that other applications can be envisaged, in particular in vehicle glazing (apart from the windshield where very high pressure is required. high light transmission), such as side glasses, car roof, rear window. The invention and its advantages are described in more detail below, by means of the non-limiting examples below, according to the invention and for comparative purposes. In all the examples and the description, the thicknesses given are physical.

All the substrates are made of 6 mm thick clear glass of the Planilux® type marketed by the company Saint-Gobain Glass France.

All the layers are deposited in a known manner by cathodic sputtering assisted by a magnetic field (often called a magnetron).

In a well-known manner, the various successive layers are deposited in the successive compartments of the cathode sputtering device, each compartment being provided with a specific metal target in Si, or Cr, under conditions chosen for the deposition of a specific layer of stacking.

For example, the silicon nitride layers are deposited in a first compartment of the device from a metallic silicon target (doped with 8% by mass of aluminum), in a reactive atmosphere containing nitrogen (40% Ar and 60% N ₂ ). The silicon nitride layers, denoted S1 ₃ N ₄ therefore contain a little aluminum. These layers are designated hereafter according to the conventional general formulation S1 ₃ N ₄ , even if the deposited layer does not necessarily correspond to this assumed stoichiometry.

The metallic chromium layers are deposited from the sputtering of a metallic Cr target in an inert atmosphere (i.e. by means of a plasma obtained from argon gas alone) or in a generated plasma. from Argon gas.

Examples 1 to 5: In all of the examples 1 to 5 which follow, the glass substrate was thus successively covered with a stack of layers comprising a functional layer of chromium surrounded by a first layer (under layer) of S13N4 and by a second layer (overcoat). of S13N4. In these examples, the stack therefore consists of a layer of chromium encapsulated with two layers of silicon nitride according to the following sequence:

Glass / S13N4 (1 ^st layer) / Cr / S13N4 (2 ^nd layer)

Different stacks are synthesized to adjust the solar factor and the light transmission to different possible configurations sought in the building industry.

Thus in Example 1 the thicknesses of the different layers are configured so as to obtain a glazing having a low solar factor, while for Example 5, the aim is, on the contrary, to maximize the light transmission through the glazing.

The glass articles thus synthesized using conventional techniques are then heated and tempered using conventional techniques in the field (heating at 620 ° C. for 10 minutes followed by quenching).

Table 1 below groups together the information concerning the constitution of the sunscreen stacks according to Examples 1 to 5 according to the invention:

[Table 1]

The values of light transmission TL and of the external Rext and internal light reflections R t are measured in the range 380 nm to 780 nm according to the methods described in standard NF EN 410 (2011). The solar factor g is also measured according to this standard, in the range 300 nm to 2500 nm.

The results obtained are collated in Table 2 below: [Table 2]

It can be seen that the glass articles according to Examples 1 to 5 fulfilling the conditions set out above for obtaining private solar protection glazing, the values of TL and g being able to be adjusted according to the thickness of the chromium layer.

It is further observed that the ARL (RLext - Runt) is in all cases close to 20, or even substantially greater than 20, which makes it possible to guarantee the “private” properties of such glazing, in the sense described above.

The colorimetric values in transmission, internal reflection and external reflection according to the L, a *, b * standard are reported in Table 3 below:

[Table 3]

It can be seen that the values of the coefficients a * and b * are relatively low and in all cases less than or equal to 8, which reflects a relative neutrality of the color perceived both in reflection and in transmission.

Comparative examples: The properties of the stacks of application WO 01/21540 cited above can be compared with those of the stacks according to the invention and described above.

Example 4 of application W001 / 21540 describes a stack comprising the following succession of layers:

Glass / S13N4 (10nm) / Nb (12nm) / ShN ₄ (17nm)

In the table on page 18 of this publication, it is stated that the light transmission is 32%. We can calculate that the solar factor g is about 36%. The values of Ri_ext and Runt reported in the publication are respectively equal to 14 and 25%.

If the values of TL and g of this example according to the prior art are comparable to examples 2 or 3 reported in table 2 above, it can be seen that the values of the exterior and interior reflections do not make it possible to obtain the private glazing, in the sense described above, the ARL being even negative in this configuration.

Likewise, example 6 of application W001 / 21540 describes a succession of layers in the stack:

Glass / S13N4 (10nm) / NbN (10nm) / ShN ₄ (15nm)

In the table on page 18 of this publication it is stated that the light transmission is 31%. We can calculate that the solar factor g is about 48%. The values of Ri_ext and Runt reported in the publication are respectively equal to 18 and 28%.

If the values of TL and g of this example according to the prior art are comparable to example 4 reported in table 2 above, it can be seen that the values of the exterior and interior reflections do not make it possible to obtain the private glazing, in the sense described above, the ARL being even negative in this configuration.

Example 6:

In this example, a stack comprising two chromium layers and corresponding to the following succession of layers was deposited:

Glass / Si ₃ N ₄ / Cr / Si ₃ N / Cr / Si ₃ N

The exact compositions of the stacks are given in Table 4 below, based on the surface of the glass:

[Table 4]

The optical and energy characteristics of the glass substrate are given in Table 5 below:

[Table 5]

The colorimetric characteristics of the glass substrates are given in Table 6 below:

[Table 6]

The data reported in Tables 4 to 6 above show that the stacks according to the invention comprising two chromium-based layers also exhibit very high color neutrality.

Claims

1. Transparent glass article, comprising at least one glass substrate provided on at least one of its faces with a coating consisting of a stack of thin layers, including at least one functional layer giving said article solar control properties, said coating comprising the succession of following layers, with reference to the surface of said substrate: a first layer comprising silicon nitride, a functional layer based on metallic chromium, with a physical thickness greater than or equal to 1 nm and less than or equal to 9 nm, a second layer comprising silicon nitride, wherein said first and second layers comprising silicon nitride are directly in contact with the functional layer based on metallic chromium.

2. Article according to claim 1, wherein the first layer comprising silicon nitride has a thickness between 1 and 100 nm, preferably between 10 and 80 nm.

3. Article according to one of the preceding claims, wherein the second layer comprising silicon nitride has a thickness between 1 and 100 nm, preferably between 1 and 50 nm, more preferably between 2 and 25 nm.

4. Article according to one of the preceding claims, wherein the first layer comprising silicon nitride is thicker than the second layer comprising silicon nitride.

5. Article according to one of the preceding claims, wherein the stack does not include layers based on Ag, Au, Pt, Cu, Ni or stainless steel.

6. Article according to one of the preceding claims, comprising a single functional layer based on metallic chromium.

7. Article according to the preceding claim, in which the stack consists of the succession of the following layers:

SiNx / Cr / SiNx in which SiN _x denotes said layer comprising silicon nitride and Cr denotes said layer based on metallic chromium.

8. Article according to one of claims 1 to 5, characterized in that the stack comprises two functional layers based on chromium, a third layer comprising silicon nitride being interposed in the stack between the two functional layers based on chromium.

9. Article according to the preceding claim, in the third layer of chromium is directly in contact with the chromium-based layers, according to the following succession of layers:

10. Article according to one of the preceding claims, in which the functional layer (s) based on chromium comprises more than 70 atomic% of chromium.

11. Article according to one of the preceding claims, in which the functional layer or layers consist essentially of chromium and preferably consist of chromium, apart from inevitable impurities.

12. Article according to one of the preceding claims, wherein the first layer comprising silicon nitride is deposited directly on the glass substrate and is in contact therewith.

13. Article according to one of claims 1 to 11, wherein at least one layer comprising a metal oxide is present between the surface of the glass substrate and the first layer comprising silicon nitride, the metal oxide preferably being chosen from among an oxide of an element chosen from silicon, titanium, tin, zinc, aluminum, zirconium or a mixture of at least two of these elements, in particular silicon oxide, titanium oxide or an oxide of zinc and tin.

14. Article according to one of the preceding claims, wherein at least one layer comprising a metal oxide is present above said succession of layers, the metal oxide preferably being chosen from an oxide of an element chosen from among silicon, titanium, tin, zinc, aluminum or a mixture of at least two of these elements, in particular silicon oxide, titanium oxide, zirconium oxide or a mixture of these oxides.

15. Article according to one of the preceding claims, characterized in that it is thermally hardened and / or curved.

16. Spandrel-type facade cladding panel incorporating at least one article according to one of the preceding claims.