LOW-EMISSIVITY MATERIAL WITH HIGH SELECTIVITY AND GLAZING COMPRISING SUCH A MATERIAL

Abstract

A material includes a transparent substrate coated with a stack including at least one silver-based functional metallic layer and at least two dielectric coatings, each dielectric coating including at least one dielectric layer, so that each functional metallic layer is positioned between two dielectric coatings, wherein the stack includes two blocking layers located in contact, below and above, with a silver-based functional metallic layer, the blocking layers being chosen from metallic layers based on a metal or a metal alloy of one or more elements chosen from titanium, nickel, chromium, tantalum, zirconium and niobium, and a titanium nitride layer located in contact with a blocking layer and separated from the silver-based functional layer by the blocking layer.

Claims

1. A material comprising a transparent substrate coated with a stack comprising at least one silver-based functional metallic layer and at least two dielectric coatings, each dielectric coating including at least one dielectric layer, so that each silver-based functional metallic layer is positioned between two dielectric coatings, wherein the stack comprises: two blocking layers located in contact, below and above, with one of the at least one silver-based functional metallic layer, the two blocking layers being chosen from metallic layers based on a metal or a metal alloy of one or more elements chosen from titanium, nickel, chromium, tantalum, zirconium and niobium, a titanium nitride layer located in contact with one of the two blocking layers and separated from the one of the at least one silver-based functional layer by said one of the two blocking layers.

2. The material according to claim 1, wherein the titanium nitride layer is located above the one of the at least one silver-based functional layer.

3. The material according to claim 1, wherein the titanium nitride layer has a thickness greater than or equal to 2 nm.

4. The material according to claim 1, wherein the titanium nitride layer has a thickness of between 5 and 15 nm.

5. The material according to claim 1, wherein the one of the two blocking layers in contact with the titanium nitride layer has a thickness less than a thickness of the other one of the two blocking layers which is not in contact with the titanium nitride layer.

6. The material according to claim 1, wherein the two blocking layers each have a thickness of between 0.1 and 5.0 nm.

7. The material according to claim 1, wherein each dielectric coating comprises a dielectric layer comprising silicon and/or aluminum selected from layers based on silicon and/or aluminum nitride or oxynitride.

8. The material according to claim 1, the wherein a sum of the thicknesses of all layers comprising silicon and/or aluminum in each dielectric coating is greater than 50% of a total thickness of the dielectric coating.

9. The material according to claim 1, the wherein a sum of thicknesses of all oxide-based layers in each dielectric coating is less than 20% of a total thickness of the dielectric coating.

10. The material according to claim 1, wherein the dielectric coating furthest from the transparent substrate comprises a protective layer chosen from a layer based on titanium, zirconium, hafnium, silicon, zinc and/or tin and mixtures thereof, metals which is/are in metallic, oxidized or nitrided form.

11. The material according to claim 1, wherein the transparent substrate coated with the stack is bent and/or tempered.

12. The material according to claim 1, wherein the transparent substrate is made of glass or of polymer organic material.

13. A glazing comprising a material according to claim 1, wherein the glazing is a monolithic, laminated and/or multiple glazing.

14. The glazing according to claim 13, wherein the glazing is a multiple glazing and comprises a material and at least one additional substrate, the material and the additional substrate being separated by at least one interlayer gas gap.

15. The glazing according to claim 14, wherein the glazing is a laminated glazing and comprises a material and at least one additional substrate, the material and the additional substrate being separated by at least one lamination interlayer.

16. The material according to claim 12, wherein the glass is soda-lime-silica glass.

Description

EXAMPLES

I. Descriptions of Materials

[0205] Stacks of thin layers defined below are deposited on substrates made of clear soda-lime glass with a thickness of 4 mm.

[0206] For these examples, the conditions of deposition of the layers deposited by sputtering (“magnetron cathode” sputtering) are summarized in table 1 below.

TABLE-US-00001 TABLE 1 Table Targets employed Pressure μbar Gas Si.sub.3N.sub.4 Si:Al 92/8% by wt 2-7 Ar 60%—O.sub.2 40% TiN Ti  1-10 Ar 85%—N2 15% NiCr Ni:Cr (80:20% at.) 2 Ar at 100% Ag Ag 6 Ar at 100% TiO.sub.2 TiOx 2 Ar 88%—O.sub.2 12% at.: atomic; wt: weight; *: at 550 nm.

[0207] The materials and the physical thicknesses in nanometers (unless otherwise indicated) of each layer or coating of which the stacks are composed are listed in table 2 below as a function of their positions with regard to the substrate bearing the stack.

TABLE-US-00002 TABLE 2 Materials Cp-1 Cp-2 Cp-3 Cp-4 Inv-1 Inv-2 Inv-3 DC TiO.sub.2 1 1 4 1 1 4 1 Si.sub.3N.sub.4 46 46 46 46 46 46 46 TiN — — — 13.52 8.5 8 — BL NiCr 2.5 2.5 2.5 — 0.8 1.3 2.5 FL Ag 13 15.5 10 13 13 10 13 BL NiCr 2.5 2.5 2.5 2.5 2.5 1.3 0.8 DC TiN — — — — — — 9 Si.sub.3N.sub.4 12 12 9 12 12 9 12 Substrate: glass DC: Dielectric coating; BL: Blocking layer; FL: Functional layer

II. Energy Performance: First Series

[0208] Table 3 below lists the optical and energy performance levels of the materials of the examples Cp-1, Cp-2, Cp-4, Inv-1 and Inv-2 in double glazing form. The double glazing has a configuration: 6-16(Ar-90%)-4, that is to say a configuration made up of a material comprising a substrate of ordinary soda-lime glass type of 4 mm and another glass substrate of soda-lime glass type of 4 mm, the two substrates are separated by an interlayer gas gap formed of 90% argon and 10% air with a thickness of 16 mm. The stacks are positioned on face 2. The material coated with the stack was not subjected to heat treatment. These results were obtained by simulation.

TABLE-US-00003 TABLE 3 Table 3 Cp-1 Cp-2 Cp-4 Inv-1 Inv-3 TL % 42 40 43 42 43 a* (T) −3.12 −3.38 −2.61 −3.04 −3.79 b* (T) −1.13 −1.07 1.76 1.99 −1.31 Rext % 28 31 31 31 25 a* (Rext) −1.42 −0.91 −3.99 −3.09 −2.06 b* (Rext) −11.63 −9.83 −7.76 −9.60 −2.94 Rint % 11 12 11 12 11 a* (Rint) 7.72 8.32 1.09 4.23 7.54 b* (Rint) −11.47 −11.28 −12.29 −14.25 −7.27 g-value 0.34 0.32 0.33 0.32 0.33 s 1.24 1.28 1.29 1.30 1.32 The comparative example Cp-1 shows the state of the art.

[0209] Example Inv-1 according to the invention has a light transmission equivalent to that of Cp-1. Its selectivity is higher than that of Cp-1 (+0.06).

[0210] This shows the advantage of the invention.

[0211] Example Inv-3 according to the invention has a light transmission equivalent to that of Cp-1. Its selectivity is higher than that of Cp-1 (+0.08). This shows the advantage of the invention.

[0212] Example Cp-2 shows that these advantageous results are not obtained using a thicker silver layer. Example Cp-2 comprises the same dielectric layers and blocking layers (natures and thicknesses) and a thicker silver layer than the comparative example Cp-1. This material has a lower light transmission and a higher external reflection than those of example Cp-1. Its selectivity is however improved relative to Cp-1 (Cp-1=1.24 and Cp-2=1.28) but remains lower than that of example 1 (Inv-1=1.30 and Cp-2=1.28). Increasing the amount of silver makes it possible to partially compensate for the selectivity but at the price of a lower light transmission.

[0213] Example Cp-4 comprising only a titanium nitride layer in contact with the functional layer has an improved selectivity. However, the selectivity remains less advantageous than that obtained with the examples according to the invention. But most importantly, such a material remains extremely scratchable. The presence of a metal blocking layer as claimed between the titanium nitride layer and the silver layer is essential in order to obtain satisfactory scratch resistance.

[0214] This shows that the introduction of a titanium nitride layer in contact with a blocking layer has a beneficial effect on the energy performance of the glazing. This beneficial effect cannot be obtained by adjusting the thickness of the silver layer.

II. Energy Performance: Second Series

[0215] These results were obtained on prototypes, that is to say that the corresponding glazings have actually been manufactured.

[0216] Table 4 lists the optical and energy performance of the materials covered by the examples: [0217] DGU-Cp-3 and DGU-Inv-2: double glazing in a 6-16(Ar-90%)-4 configuration with the stack positioned on face 2, the substrate bearing the stack has not undergone a high-temperature heat treatment, [0218] DGU TT-Cp-3 and DGU TT-Inv-2: double glazing in a 6-16(Ar-90%)-4 configuration with the stack positioned on face 2, the substrate bearing the stack has undergone a high-temperature heat treatment. [0219] Laminated-Cp-3 and Laminated-Inv-2: laminated glazing in a 4 mm Substrate/0.38 mm PVB Interlayer/4 mm Substrate configuration with the stack positioned on face 2, the substrate bearing the stack has not undergone a high-temperature heat treatment.

[0220] The high-temperature heat treatment is carried out as follows: [0221] rise in temperature to 700° C. in 300-350 s, [0222] remaining at 700° C. for 30-50 s, [0223] lowering the temperature in 100-150 s.

TABLE-US-00004 TABLE 4 DGU DGU TT Laminated Cp-3 Inv-2 Cp-3 Inv-2 Cp-3 Inv-2 TL % 42.3 43.0 43.5 47.2 42.6 44.7 a* (T) −3.5 −2.9 −3.0 −3.5 −2.9 −3.1 b* (T) 1.1 2.9 0.7 2.3 −2.1 −0.4 Rext % 29.5 31.5 27.0 29.8 26.6 27.0 a* (Rext) −4.0 −5.1 −4.5 −4.3 −1.5 −1.5 b* (Rext) −8.7 −7.4 −8.5 −8.4 −1.5 −1.1 Rint % 10.6 11.3 10.2 12.7 10.5 9.4 a* (Rint) 5.2 0.8 3.4 0.0 3.2 2.6 b* (Rint) −15.9 −14.1 −14.7 −14.4 −3.4 −0.6 g-value 0.342 0.342 0.354 0.357 0.403 0.402 s 1.24 1.26 1.23 1.32 1.06 1.11

[0224] In all cases, an improvement in selectivity is observed in the case of the invention. The effect on selectivity is more pronounced on tempered or laminated glazings.

[0225] It is also observed that the use of a titanium nitride layer, in addition to its influence on the tempered and laminated energy configuration, also partially neutralizes the internal reflection color of the glazings.