SUBSTRATE PROVIDED WITH A STACK HAVING THERMAL PROPERTIES AND AN ABSORBENT LAYER

Abstract

A substrate which is coated on one of its faces with a stack of thin layers having reflection properties in the infrared and/or in solar radiation, including two metallic functional layers, in particular based on silver. Each of the metallic functional layers is disposed between two dielectric coatings. The dielectric coating Di2 situated between the two functional layers includes at least one absorbent layer which absorbs solar radiation in the visible part of the spectrum. It has been found that for a stack for laminated glazing, some symmetry at the functional metal layers and the dielectric layers 1 and 3 is favorable.

Claims

1. A substrate coated on one face with a stack of thin layers forming a functional coating which is adapted to act on solar radiation and/or infrared radiation, said functional coating comprising two metallic functional layers, each arranged between two dielectric coatings, so as to comprise a sequence of layers, first dielectric layer Di1/first metallic functional layer F1/second dielectric layer Di2/second metallic functional layer F2/third dielectric layer Di3, starting from the substrate, each dielectric coating comprising at least one layer of dielectric material, wherein: the second dielectric coating Di2 located between the first and second metallic functional layers F1,F2 comprises at least one absorbent layer which absorbs solar radiation in the visible part of the spectrum, the first and second metallic functional layers F1, F2 have a ratio of thickness of the second metallic functional layer F2 to the first metallic functional layer F1 of between 0.5 and 1.5; the first and third dielectric coatings Di1, Di3 have a ratio of optical thickness of the third dielectric coating Di3 to the first dielectric coating Di1 of between 0.5 and 1.5.

2. The coated substrate according to claim 1, wherein, when the functional coating comprises a blocking layer located below the first metallic functional layer, a thickness of said blocking underlayer is strictly less than 1 nm.

3. The coated substrate according to claim 1, wherein the functional coating comprises a metal blocking layer deposited on at least one of the first and second metallic metallic functional layers.

4. The coated substrate according to claim 1, wherein a sum of thicknesses of all blocking layers located in contact with the functional layers in the functional coating is less than 4 nm.

5. The coated substrate according to claim 1, wherein each dielectric coating comprises a dielectric layer based on silicon and/or aluminum nitride.

6. The coated substrate according to claim 1, wherein the first dielectric coating located below the first metallic functional layer comprises: a dielectric layer based on silicon and/or aluminum nitride, a dielectric layer based on oxide, optionally a blocking layer, the oxide layer is located in contact with the first metallic functional layer or in contact with the blocking layer.

7. The coated substrate according to claim 1, wherein the absorbent layer is separated from each of the first and the second metallic functional layer F1, F2 by at least one layer of dielectric material selected from layers based on silicon and/or aluminum nitride.

8. The coated substrate according to claim 1, wherein the absorbent layer is either based on metal, nitride, oxide, or oxynitride.

9. The coated substrate according to claim 1, wherein the absorbent layer is selected from layers based on one of the following materials: Ti, NiCr, Nb, Zr, NiCuCr, NbN, TiN, ZrN, NbN, TiZrN or TiNO, NbNO, or mixtures thereof.

10. The coated substrate according to claim 1, having a light transmission that is less than 40% when the light transmission is measured in a configuration: 4 mm-thick clear glass/stack/PVB (38 mm)/4 mm-thick clear glass.

11. The coated substrate according to claim 1, having a selectivity of greater than 1.05% when the selectivity is measured in a configuration: 4 mm-thick clear glass/stack/PVB (38 mm)/4 mm-thick clear glass.

12. The coated substrate according to claim 1, wherein an uncoated face of the substrate is intended to form an outer side of a glazing, a light reflection on the outer side being less than 25% when the light reflection is measured in a configuration: 4 mm-thick clear glass/stack/PVB (38 mm)/4 mm-thick clear glass.

13. The coated substrate according to claim 1, wherein the dielectric coatings comprise a layer of nitride-based dielectric material and a layer of oxide-based dielectric material, the oxide-based layer being on a side of the metallic functional layer.

14. A laminated glazing comprising two transparent substrates, between which an adhesive interlayer is inserted, wherein one of the two transparent substrates is a coated substrate according to claim 1.

15. The laminated glazing according to claim 14, wherein the coated substrate is arranged on an outer side of the glazing.

16. The coated substrate according to claim 4, wherein the sum of thicknesses of all blocking layers located in contact with the functional layers in the functional coating is less than 3.5 nm.

17. The coated substrate according to claim 16, wherein the sum of thicknesses of all blocking layers located in contact with the functional layers in the functional coating is less than 3 nm.

18. The coated substrate according to claim 6, wherein the dielectric layer based on oxide is zinc oxide.

Description

EXAMPLES

[0086] Table 1 below shows the geometric thicknesses in nanometers of each of the layers of the stacks produced for the comparative examples (C1 to C3) and the examples according to the invention (Ex. 1 to 6).

[0087] The comparative example C1 is similar to the stacks according to the invention but does not comprise an absorbent layer.

[0088] The comparative example C2 is a stack of layers corresponding to that described in example 5bis of patent EP 1341732 B1.

[0089] The comparative example C3 is a stack of layers corresponding to that described in example 2 of application WO2018/875005.

TABLE-US-00001 TABLE 1 C1 C2 C3 Ex. 1 Ex. 2 Di3 Si.sub.3N.sub.4 38.3 20.0 39.9 31.9 36.1 AZO 4.0 12.9 / 4.0 4.0 M2 NiCr 0.9 1.0 0.3 1.0 1.0 F2 Ag 6.4 17.5 6.4 10.3 10.6 B2 NiCr / / 2.0 / / Di2b AZO 4.0 12.9 / 4.0 4.0 Si.sub.3N.sub.4 75.6 30.0 51.9 49.3 41.8 A TiN / 2.0 / 14.1 / NbN / / / / 5.3 NbZrON / / 8.4 / / Di2a Si.sub.3N.sub.4 / 30.0 43.0 51.2 37.5 AZO 4.0 12.9 / 4.0 4.0 M1 NiCr 7.3 1.0 1.4 1.0 1.0 F1 Ag 11.3 6.4 13.0 10.6 10.8 B1 NiCr / / 1.2 / / Di1 AZO 4.0 12.9 / 4.0 4.0 Si.sub.3N.sub.4 36.3 29.0 67.4 32.1 32.0 substrate Glass

[0090] Table 2 below summarizes the main optical and energy characteristics obtained in a configuration:

Outside/4mm-thick clear glass/stack/PVB (38 mm)/4 mm-thick clear glass/Inside

TABLE-US-00002 TABLE 2 C1 C2 C3 Ex. 1 Ex. 2 F2/F1 0.57 2.73 0.49 0.97 0.98 Di3/Di1 1.05 0.79 0.59 0.99 1.11 TL % 37.0 44.3 47.3 33.5 35.6 g % 29.5 34.4 24.6 28.7 31.1 S 1.25 1.4 1.16 1.17 1.14 RL.sub.ext % 29.8 15.1 27.5 20.0 17.4 RL.sub.int % 20 25.3 8.3 18.7 12.7 a* T −5.1 −7.7 −8.0 −3.9 −4.3 b* T −0.8 −3.6 +7.8 −2.8 −0.8 a* R.sub.ext +3.2 +0.7 +4.0 −6.8 −1.0 b* R.sub.ext +1.9 −9.4 −12.1 −0.7 −5.3 a* R.sub.int +0.2 +7.6 −0.6 −6.3 −0.7 b* R.sub.int +2.2 +10.9 −26.4 −3.2 −4.4 a* R.sub.ext 45 +2.1 +3.0 +5.3 −5.9 +0.1 b* R.sub.ext 45 +3.5 −7.8 −9.3 −2.7 −4.8 a* R.sub.ext 60 −3.4 +4.1 +5.0 −4.2 +0.9 b* R.sub.ext 60 −6.7 −7.2 −7.2 −4.0 −4.9 t.sub.abs. effective nm 0 5.4 Not 76.8 64.4 determined

[0091] In conclusion, it can be seen that the examples according to the invention make it possible to produce laminated glazings with a light transmission of the order of 35% while combining low solar factors (g of less than 32%) and low light reflection (RL.sub.ext of less than 20%) and while providing a desired appearance.

[0092] The comparative examples either have a higher TL or a higher RL.sub.ext, or both.

[0093] What is particularly noteworthy is that the color in reflection on the outer side was able to be kept in the neutral zones, which is not the case for the comparative examples.

[0094] The angular stability of the outer color in reflection is particularly improved with respect to the stacks of the comparative examples. Example 2, most particularly, shows a difference of less than 1 between the value of the coefficient b* at the normal (−5.3) and the value at 45° (−4.8) or 60° with respect to the normal (−4.9).

[0095] The present invention is described in the preceding text by way of example. Of course, those skilled in the art are capable of implementing different variants of the invention without departing from the scope of the patent such as defined by the claims.