Substrate provided with a stack having thermal properties

Abstract

A material includes a transparent substrate coated with a stack of thin layers successively including, starting from the substrate, an alternation of three silver-based functional metallic layers and of four dielectric coatings, referred to, starting from the substrate, as M1, M2, M3 and M4, wherein the thickness of the first functional layer is less than the thickness of the second functional layer and less than the thickness of the third functional layer, the dielectric coatings M1 and M2 each have an optical thickness Eo1 and Eo2 satisfying the following equation: Eo2<1.1 Eo1.

Claims

1. A material comprising a transparent substrate coated with a stack of layers successively comprising, starting from the substrate, an alternation of three silver-based functional metallic layers referred to, starting from the substrate, as first, second and third functional layers and of four dielectric coatings, referred to, starting from the substrate, as a first dielectric coating M1, a second dielectric coating M2, a third dielectric coating M3 and a fourth dielectric coating M4, each dielectric coating comprising at least one dielectric layer, so that each functional metallic layer is positioned between two dielectric coatings, wherein: a thickness of the first functional layer is less than a thickness of the second functional layer, a thickness of the second functional layer is less than a thickness of the third functional layer, the thickness of the third functional layer is between 13 and 20 nm, and the first and second dielectric coatings M1 and M2 each have an optical thickness Eo1 and Eo2 satisfying the following equation: Eo2<1.1 Eo1, wherein the material has a light transmission of less than 60.0% and a light reflection on the external side of greater than or equal to 20.0%.

2. The material as claimed in claim 1, wherein a ratio of the thickness of the third functional metallic layer to the thickness of the second functional layer is between 0.90 and 1.10, including these values.

3. The material as claimed in claim 1, wherein the stack also comprises at least one blocking layer located in contact with a functional layer, the at least one blocking layer being selected from the group consisting of a metallic layer based on a metal or on a metal alloy, a metal nitride layer, a metal oxide layer and a metal oxynitride layer of one or more elements selected from titanium, nickel, chromium and niobium.

4. The material as claimed in claim 3, wherein a total thickness of all the blocking layers in contact with the functional layers is between 0.1 and 2 nm, including these values.

5. The material as claimed in claim 3, wherein at least one blocking layer is Ti, TiN, TiOx, Nb, NbN, Ni, NiN, Cr, CrN, NiCr or NiCrN layer.

6. The material as claimed in claim 1, wherein the dielectric coatings satisfy the following characteristics: the optical thickness of the first dielectric coating M1 is from 85 to 150 nm, the optical thickness of the second dielectric coating M2 is from 80 to 150 nm, the optical thickness of the third dielectric coating M3 is from 135 to 220 nm, the optical thickness of the fourth dielectric coating M4 is from 65 to 120 nm.

7. The material as claimed in claim 1, wherein each of the dielectric coatings comprises at least one dielectric layer having a barrier function based on silicon and/or aluminum compounds selected from oxides, silicon nitrides Si.sub.3N.sub.4 and AlN and oxynitrides SiO.sub.xN.sub.y and AlO.sub.xN.sub.y.

8. The material as claimed in claim 7, wherein the oxides are SiO.sub.2 and Al.sub.2O.sub.3.

9. The material as claimed in claim 1, wherein each dielectric coating comprises at least one dielectric layer having a stabilizing function based on a crystalline oxide.

10. The material as claimed in claim 9, wherein the crystalline oxide is zinc oxide, optionally doped with aluminum.

11. The material as claimed in claim 1, wherein each functional layer is on top of a dielectric coating, an upper layer of which is a dielectric layer having a stabilizing function and/or underneath a dielectric coating, a lower layer of which is a dielectric layer having a stabilizing function.

12. The material as claimed in claim 11, wherein the upper layer and lower layer are zinc oxide layers.

13. The material as claimed in claim 1, wherein the stack, defined starting from the transparent substrate, comprises: the first dielectric coating comprising at least one dielectric layer having a barrier function and one dielectric layer having a stabilizing function, optionally a blocking layer, the first functional layer, optionally a blocking layer, the second dielectric coating comprising at least one lower dielectric layer having a stabilizing function, one dielectric layer having a barrier function and one upper dielectric layer having a stabilizing function, optionally a blocking layer, the second functional layer, optionally a blocking layer, the third dielectric coating comprising at least one lower dielectric layer having a stabilizing function, one dielectric layer having a barrier function and one upper dielectric layer having a stabilizing function, optionally a blocking layer, the third functional layer, optionally a blocking layer, the fourth dielectric coating comprising at least one dielectric layer having a stabilizing function, one dielectric layer having a barrier function and optionally one protective layer.

14. The material as claimed in claim 1, wherein the thickness of the first functional layer is between 6 and 12 nm, and the thickness of the second functional layer is between 13 and 20 nm.

15. A glazing comprising at least one material as claimed in claim 1.

16. The glazing as claimed in claim 15, wherein the stack is positioned in the glazing so that the incident light coming from outside passes through the first dielectric coating before passing through the first functional metallic layer.

17. The glazing as claimed in claim 15, wherein the glazing is in the form of monolithic, laminated or multiple glazing.

18. The glazing as claimed in claim 17, wherein the multiple glazing is a double glazing or triple glazing.

19. A process for obtaining a material as claimed in claim 1, comprising depositing the layers of the stack by magnetron sputtering.

Description

EXAMPLES

(1) I. Preparation of the Substrates: Stacks, Deposition Conditions and Heat Treatments

(2) Stacks, defined below, of thin layers are deposited on substrates made of clear soda-lime glass with a thickness of 6 mm.

(3) In the examples of the invention: the functional layers are layers of silver (Ag), the blocking layers are metallic layers made of nickel-chromium alloy (NiCr), the barrier layers are based on silica nitride, doped with aluminum (Si.sub.3N.sub.4:Al), the stabilizing layers are made of aluminum-doped zinc oxide (ZnO).

(4) The conditions for deposition of the layers, which were deposited by sputtering (magnetron sputtering), are summarized in table 1.

(5) TABLE-US-00001 TABLE 1 Target employed Deposition pressure Gas n 550 nm Si.sub.3N.sub.4 Si:Al at 92:8% by weight 3.2 10.sup.3 mbar Ar/(Ar + N2) at 55% 2.03 ZnO Zn:Al at 98:2% by weight 1.8 10.sup.3 mbar Ar/(Ar + O2) at 63% 1.95 TiZrO TiZrOx 2-4 10.sup.3 mbar Ar 90% - O.sub.2 10% 2.32 NiCr Ni (80 at. %):Cr (20 at. %) 2-3 10.sup.3 mbar Ar at 100% Ag Ag .sup.3 10.sup.3 mbar Ar at 100% at. = atomic

(6) Table 2 lists the materials and the physical thicknesses in nanometers (unless otherwise indicated) for each layer or coating that forms the stacks as a function of their position with respect to the substrate bearing the stack (final line at the bottom of the table). The Ref. numbers correspond to the references from FIG. 1.

(7) TABLE-US-00002 TABLE 2 Ref. Inv. 1 Inv. 2 Inv. 3 Dielectric coating M4 140 43 42 50 TiZrOx 160 2 2 2 Si.sub.3N.sub.4 144 33 32 40 ZnO 142 8 8 8 Blocking layer NiCr 130 0.1 0.1 0.4 Functional layer Ag3 120 15.5 15.4 14 Blocking layer NiCr 110 0 0 0.3 Dielectric coating M3 100 84 82 98 ZnO 108 8 8 8 Si.sub.3N.sub.4 104 68 66 82 ZnO 102 8 8 8 Blocking layer NiCr 90 0.6 0.6 0.2 Functional layer Ag2 80 15.8 15.6 15.5 Blocking layer NiCr 70 0 0 0.1 Dielectric coating M2 60 56 55 67 ZnO 68 8 8 8 Si.sub.3N.sub.4 64 40 39 51 ZnO 62 8 8 8 Blocking layer NiCr 50 0.1 0.1 0.1 Functional layer Ag1 40 7 7 7 Blocking layer NiCr 30 0 0 0.1 Dielectric coating M1 20 56 57 66 ZnO 28 8 8 8 Si.sub.3N.sub.4 24 48 49 58 Glass substrate (mm) 10 6 6 6

(8) Each dielectric coating 20, 60, 100 underneath a functional layer 40, 80, 120 comprises a final stabilizing layer 28, 68, 108 based on crystalline zinc oxide, and which is in contact with the functional layer 40, 80, 120 deposited immediately on top.

(9) Each dielectric coating 60, 100, 140 on top of a functional layer 40, 80, 120 comprises a first stabilizing layer 62, 102, 142 based on crystalline zinc oxide, and which is in contact with the functional layer 40, 80, 120 deposited immediately on top.

(10) Each dielectric coating 20, 60, 100, 140 comprises a dielectric layer having a barrier function 24, 64, 104, 144, based on silica nitride, doped with aluminum, referred to here as Si.sub.3N.sub.4.

(11) Each functional metallic layer 40, 80, 120 is underneath and in contact with a blocking layer 50, 90 and 130.

(12) Each functional metallic layer 40, 80, 120 may be on top of a blocking layer 30, 70 and 110 (not represented in FIG. 1).

(13) The stack also comprises a protective layer made of titanium zirconium oxide 160 (not represented in FIG. 1).

(14) Table 3 summarizes the characteristics linked to the thicknesses of the functional layers and of the dielectric coatings.

(15) TABLE-US-00003 TABLE 3 Inv. 1 Inv. 2 Inv. 3 Dielectric coating Ep Eo Ep Eo Ep Eo M1 56 113.04 57 115.07 66 133.34 M2 56 112.4 55 110.37 67 134.73 M3 84 169.24 82 165.18 98 197.66 M4 43 87.23 42 85.2 50 101.44 1.1*Eo1 124.34 126.58 146.67 Eo2 < 1.1*Eo1 Yes Yes Yes Ag1 < Ag2 and Ag3 Yes Yes Yes Ag3/Ag2 0.98 0.99 0.90 Ep: physical thickness (nm); Eo: optical thickness (nm).
II. Solar Control and Colorimetry Performances

(16) Table 4 lists the main optical characteristics measured when the glazings are part of double glazing having a 6/16/4 structure: 6 mm glass/16 mm interlayer space 90% filled with argon/4 mm glass, the stack being positioned on face 2 (face 1 of the glazing being the outermost face of the glazing, as is customary).

(17) For these double glazings, T.sub.L indicates: the light transmission in the visible region in %, measured according to the illuminant D65 at 2 observer; a*T and b*T indicate the a* and b* colors in transmission in the L*a*b* system measured according to the illuminant D65 at 2 observer and measured perpendicularly to the glazing; R.sub.Lext indicates: the light reflection in the visible region in %, measured according to the illuminant D65 at 2 observer on the side of the outermost face, face 1; a*R.sub.ext and b*R.sub.ext indicate the a* and b* colors in reflection in the L*a*b* system measured according to the illuminant D65 at 2 observer on the side of the outermost face and thus measured perpendicularly to the glazing, R.sub.Lint indicates: the light reflection in the visible region in %, measured according to the illuminant D65 at 2 observer on the side of the internal face, face 4; a*R.sub.int and b*R.sub.int indicate the a* and b* colors in reflection in the L*a*b* system measured according to the illuminant D65 at 2 observer on the side of the internal face and thus measured perpendicularly to the glazing.

(18) The colorimetric values at an angle a*g60 and b*g60 are measured on single glazing under an incidence of 60. This takes into account the neutrality of the colors at an angle.

(19) TABLE-US-00004 TABLE 4 Target value Inv. 1 Inv. 2 Inv. 3 Solar factors g 27.5% 25% 25% 25% Selectivity s >1.8 2.0 2.0 2.0 T.sub.L % 50% 50 50 50 a*T <0 5.0 4.9 1.7 b*T 4.5 3.0 2.5 R.sub.Lext % >25 30 30 30 a*R.sub.ext <0 1.0 1.0 3.4 b*R.sub.ext <0 4.0 2.0 3.2 R.sub.Lint % 26 25 29 a*R.sub.int <0 4.0 4.0 1.7 b*R.sub.int <0 6.4 4.7 4.2 a*g60 4.0 4.0 4.2 b*g60 4.4 3.1 2.4

(20) According to invention, it is possible to produce a glazing comprising a stack having three functional metallic layers which has a shiny silver appearance in reflection on the external side, a light transmission of around 50%, a high selectivity, a high light reflection and a low solar factor.

(21) The examples according to the invention all have a pleasant and subdued color in transmission, preferably in the range of blues or blue-greens.

(22) The glazings according to the invention have both a solar factor of less than or equal to 25% and a selectivity of greater than 1.80. These glazings additionally have an external reflection of at least greater than 25%, or even less than 27.5%. These glazings also have neutral colors in transmission.