SOLAR-CONTROL GLAZING UNIT COMPRISING A LAYER OF TITANIUM NITRIDE

Abstract

A glass article having anti-sun properties includes a glass substrate having a stack of layers, which includes, successively from the surface of the substrate: a first module M.sub.1 having a layer based on a dielectric material with a thickness e.sub.1 or of a set of layers, a layer TN.sub.1 including titanium nitride with a thickness of between 2 nanometers and 80 nanometers, a second module M.sub.2 including a layer based on a dielectric material with a thickness e.sub.2 or of a set of layers based on dielectric materials with a cumulative thickness e.sub.2, an intermediate layer including at least one element selected from silicon, aluminum, titanium or a mixture of at least two of these elements is deposited between the layer TN.sub.1 and the first module M.sub.1 and/or between the layer TN.sub.1 and the second module M.sub.2, the intermediate layer having a thickness of between 0.2 nm and 6 nm.

Claims

1. A glass article having anti-sun properties comprising at least one glass substrate provided with a stack of layers, wherein the stack of layers comprises, successively from a surface of said substrate: a first module M.sub.1 consisting of a layer based on a dielectric material with a thickness e.sub.1 or of a set of layers based on dielectric materials with a cumulative thickness e.sub.1, said thickness e.sub.1 being between 1 and 100 nm, a layer TN.sub.1 comprising titanium nitride, with a thickness of between 2 nanometers and 80 nanometers, a second module M.sub.2 consisting of a layer based on a dielectric material with a thickness e.sub.2 or of a set of layers based on dielectric materials with a cumulative thickness e.sub.2, said thickness e.sub.2 being between 5 and 100 nm, and wherein an intermediate layer comprising at least one element selected from silicon, aluminum, titanium or a mixture of at least two of said elements is deposited between said layer TN.sub.1 and said first module M.sub.1 and/or between said layer TN.sub.1 and said second module M.sub.2, said intermediate layer having a thickness of between 0.2 nm and 6 nm.

2. The glass article according to claim 1, wherein said element deposited to constitute the intermediate layer is substantially aluminum.

3. The glass article according to claim 1, wherein said element deposited to constitute the intermediate layer is substantially silicon.

4. The glass article according to claim 1, wherein said elements deposited to constitute the intermediate layer are substantially silicon and aluminum.

5. The glass article according to claim 1, wherein said element deposited to constitute the intermediate layer is substantially titanium.

6. The glass article according to claim 1 one of the preceding claims, wherein the modules M.sub.1, M.sub.2 comprise materials selected from silicon nitride, aluminum nitride, aluminum-silicon nitride, tin oxide, mixed oxide of zinc and tin, silicon oxide, titanium oxide and silicon oxynitride.

7. The glass article according to claim 1, wherein the first module M.sub.1 comprises a layer comprising silicon nitride or silicon-aluminum nitride, said layer comprising silicon nitride or silicon-aluminum nitride still contacting an intermediate layer.

8. The glass article according to claim 1, wherein the first module M.sub.2 comprises a layer comprising silicon nitride or silicon-aluminum nitride, said layer comprising silicon nitride or silicon-aluminum nitride still contacting an intermediate layer.

9. The glass article according to claim 1, wherein at least one of the modules M.sub.1 or M.sub.2 comprises a layer comprising silicon oxynitride and/or aluminum oxynitride, the layer of silicon oxynitride and/or aluminum oxynitride still contacting an intermediate layer.

10. The glass article according to claim 1, wherein the stack of layers comprises the following sequence of layers, starting from the substrate surface: a layer based on silicon nitride or based on silicon oxynitride said intermediate layer comprising at least one element selected from silicon aluminum, titanium, or a mixture of at least two of said elements, said layer TN1, optionally a second intermediate layer comprising at least one element selected from silicon aluminum, titanium, or a mixture of at least two of said elements, a layer based on silicon nitride or a layer based on silicon oxynitride, and optionally a protective layer selected from oxides of titanium, zirconium or a mixture of titanium and zirconium.

11. The glass article according to claim 1, wherein the stack of layers comprises the following sequence of layers, starting from the substrate surface: a layer based on silicon nitride or based on silicon oxynitride, titanium, or a mixture of at least two of said elements, optionally another intermediate layer comprising at least one element selected from silicon aluminum, titanium, or a mixture of at least two of these elements, said layer TN1, said intermediate layer comprising at least one element selected from silicon aluminum, a layer based on silicon nitride or a layer based on silicon oxynitride, and optionally a protective layer selected from oxides of titanium, zirconium or a mixture of titanium and zirconium.

12. The glass article according to claim 1, wherein the stack of layers comprises a plurality of layers comprising titanium nitride, each layer comprising titanium nitride being separated from the next one in the stack by a layer based on a dielectric material or by a set of layers based on dielectric materials, and optionally an intermediate layer comprising at least one element selected from silicon and/or aluminum.

13. The glass article according to claim 1, wherein the stack of layers does not contain any layers based on silver, platinum or gold.

14. The glass article according to claim 1, wherein the glass substrate is made of clear glass.

15. The glass article according to claim 1, wherein said glass substrate or substrates provided with said stack of layers are tempered or curved.

16. The glass article according to claim 1, wherein the module M.sub.1, the layer TN.sub.1, the module M.sub.2 and the intermediate layer are deposited successively and so as to be in contact with one another.

17. The glass article according to claim 1, wherein said thickness e.sub.1 is between 10 and 70 nm.

18. The glass article according to claim 1, wherein the thickness of the layer TN1 is between 10 and 50 nm.

19. The glass article according to claim 1, wherein the thickness e.sub.2 is between 20 and 70 nm.

20. The glass article according to claim 1, wherein the intermediate layer has a thickness of between 1 nm and 4 nm.

Description

EXAMPLE 1

[0095] According to reference example 1, the glass substrate is successively covered with a stack of layers comprising an underlayer (layer M.sub.1) based on silicon nitride (hereinafter noted for convenience as Si.sub.3N.sub.4 even if this is not necessarily the actual stoichiometry of the layer), a functional layer based on titanium nitride, and an overlayer (layer M.sub.2) also based on silicon nitride (hereinafter noted for convenience as Si.sub.3N.sub.4 even if this is not necessarily the actual stoichiometry of the layer).

EXAMPLES 2 AND 3

[0096] According to examples 2 and 3 according to the invention, an intermediate layer of aluminum (example 2) or of a silicon-aluminum alloy comprising 8% by weight of aluminum (example 3) are deposited on top of the titanium nitride layer (i.e. between the TiN layer and the Si.sub.3N.sub.4 overlayer) in the stack of reference example 1.

EXAMPLE 4

[0097] According to example 4 according to the invention, a two-nanometer intermediate layer of titanium metal is deposited between the TiN layer and the Si.sub.3N.sub.4 underlayer in the stack of reference example 1.

EXAMPLE 5

[0098] According to example 5 according to the invention, a one-nanometer intermediate layer of titanium metal is deposited between the TiN layer and the Si.sub.3N.sub.4 overlayer and another one-nanometer layer of titanium metal is inserted between the TiN layer and the Si.sub.3N.sub.4 underlayer.

EXAMPLE 6

[0099] According to comparative example 6, an intermediate layer of nickel-chromium (80% by weight nickel, 20% by weight chromium) is deposited between the TiN layer and the Si.sub.3N.sub.4 overlayer in the stack of reference example 1.

EXAMPLE 7

[0100] According to comparative example 7, a 2 nm thick intermediate layer of niobium nitride is inserted between the TiN layer and the Si.sub.3N.sub.4 overlayer in the stack of reference example 1.

EXAMPLE 8

[0101] In this example, the silicon nitride overlayer constituting the module M.sub.2 in example 2 was replaced by a layer of silicon oxynitride with a refractive index at 550 nm of 1.88.

[0102] All substrates are made of 4 mm thick clear Planiclear® glass sold by Saint-Gobain Glass France. All layers are deposited in a known manner by magnetic-field-assisted sputtering (often referred to as magnetron sputtering).

[0103] The deposition conditions were adjusted according to conventional techniques for magnetron deposition in order to obtain different stacks of which the succession of layers and the thicknesses thereof (in nanometers nm) are reported in table 1 below:

TABLE-US-00001 TABLE 1 Type of Si.sub.3N.sub.4 TiN Si.sub.3N.sub.4 deposition (M.sub.1) IL* (TN.sub.1) IL* (M.sub.2) IL Example 1 30 — 20 — 30 — (reference) Example 2 30 — 20 2 30 Al (invention) Example 3 30 — 20 2 30 Si—Al (invention) Example 4 30 2 20 — 30 Ti (invention) Example 5 30 1 20 1 30 Ti (invention) Example 6 30 — 20 2 30 NiCr (comparative) Example 7 30 — 20 2 30 NbN (comparative) Example 8 30 — 20 3  30** Al (invention) *IL: intermediate layer **silicon oxynitride SiON with a refractive index of 1.88 at 550 nm.

[0104] All the glazing units thus obtained according to examples 1 to 8 are then subjected to a heat treatment at 650° C. for 10 minutes.

[0105] A—Measuring Characteristics of the Glazing Units

[0106] The thermal and optical characteristics of the glazing units before and after tempering were measured according to the following principles and standards:)

[0107] 1°) Optical Properties:

[0108] The measurements are made in accordance with the NF EN410 (2011) standard mentioned above. More precisely, the light transmission T.sub.L is measured between 380 and 780 nm according to the illuminant D.sub.65.

[0109] 2°) Thermal Properties:

[0110] The normal emissivity ε.sub.n was measured according to the ISO 10292 standard mentioned above.

[0111] B—Results

[0112] The results obtained for the monolithic glazing units according to the examples described above are compiled in table 2 below:

TABLE-US-00002 TABLE 2 T.sub.L ε.sub.n T.sub.L/ε.sub.n Example After tempering After tempering After tempering 1 (ref.) 54.1 40.6 1.33 2 (inv.) 54.5 37.9 1.44 3 (inv.) 55.5 38.0 1.46 4 (inv.) 52.7 34.8 1.51 5 (inv.) 50.7 32.6 1.56 6 (comp.) 48.5 35.8 1.35 7 (comp.) 52.5 49 1.07 8 (inv.) 53.5 34.9 1.53

[0113] Examples 2 and 3 are examples according to the present invention. For these two examples, after tempering, a light transmission of around 55% is observed, which is surprisingly higher than that of the same stack without the intermediate layer of aluminum or of an Si-Al alloy according to the invention. According to an advantageous characteristic, the emissivity at normal incidence is also significantly reduced compared to reference example 1.

[0114] Examples 4 and 5 according to the present invention show a slight decrease in light transmission but also a much decreased emissivity compared to the reference stack.

[0115] Ultimately, the use of the intermediate layer in the stack according to the invention thus makes it possible to obtain a light transmission equal to or substantially comparable to that of the reference stack, while improving the thermal properties of the glazing unit.

[0116] Ultimately, it is observed that the selectivity of the glazing unit, as measured by the T.sub.L/ε.sub.n ratio, is significantly improved for the glazing units according to the invention, especially after tempering.

[0117] The comparative glazing unit according to example 6, comprising an intermediate layer made of an NiCr alloy, has a substantially reduced light transmission compared to the reference example and the examples according to the invention, and ultimately a selectivity that is substantially equal to the reference glazing unit.

[0118] The comparative glazing unit according to example 7, comprising an NbN intermediate layer, has a degraded selectivity compared to the reference example.

[0119] The glazing unit according to example 8, in which a silicon (and aluminum) oxynitride layer is used in contact with the intermediate layer, also has improved selectivity compared to the reference example.

[0120] When considering the T.sub.L/ε.sub.n selectivities of the glazing units according to examples 1 to 8, as reported in table 2, it can be seen that the glazing units according to the invention have the best selectivities, after having undergone a thermal treatment.

[0121] According to other complementary examples, it is sought to determine what thickness of aluminum, used to constitute the intermediate layer, is optimal for selectivity by varying said thickness in the stack described according to example 2 above. The results obtained are compiled in table 3 below:

TABLE-US-00003 TABLE 3 Al layer T.sub.L After ε.sub.n After T.sub.L/ε.sub.n After Example thickness (nm) tempering tempering tempering 1 (ref.) 0 54.1 40.6 1.33 2 2 54.5 37.9 1.44 2a 1 54.7 40.1 1.44 2b 3 54.9 34.1 1.61 2c 4 52.9 32.8 1.61 2d 5 51.3 32.9 1.56

[0122] The analysis of the data reported in table 3 shows that the best results and compromises are obtained when the thickness of the aluminum intermediate layer is between 2 and 4 nm.