SOLAR CONTROL GLAZING COMPRISING A LAYER OF A NiCuCr ALLOY

Abstract

A glazing that has a solar control property includes at least one glass substrate on which a stack of layers is deposited. The stack includes at least one layer consisting of an alloy comprising nickel, copper and chromium, in which alloy the atomic percentage of nickel is greater than 70% and less than 94%, the atomic percentage of copper is greater than 5% and less than 25% and in which the atomic percentage of chromium is greater than 1% and less than 15%.

Claims

1. A glazing having a solar control property comprising: at least one glass substrate on which a stack of layers is deposited, said stack comprising at least one functional layer consisting of an alloy comprising nickel, copper and chromium, in which alloy the atomic percentage of nickel is greater than 70% and less than 94%, the atomic percentage of copper is greater than 5% and less than 25% and in which the atomic percentage of chromium is greater than 1% and less than 15%.

2. The glazing as claimed in claim 1, in which the atomic percentage of copper is greater than the atomic percentage of chromium by at least 3%.

3. The glazing as claimed in claim 1, in which the atomic percentage of copper in the alloy is between 5% and 15%.

4. The glazing as claimed in claim 1, in which the atomic percentage of nickel in the alloy is between 75% and 90%.

5. The glazing as claimed in claim 1, in which the atomic percentage of chromium in the alloy is between 2% and 10%.

6. The glazing as claimed in claim 1, in which the thickness of said functional layer is between 5 and 25 nanometers.

7. The glazing as claimed in claim 1, in which the alloy is essentially composed of nickel, of copper and of chromium.

8. The glazing as claimed in claim 1, in which the alloy does not comprise a heteroatom, such as nitrogen or oxygen, or carbon.

9. The glazing as claimed in claim 1, in which the stack consists of the sequence of the following layers, starting from the surface of the glass substrate: one or more lower layers for protection of the functional layer from the migration of the alkali metal ions resulting from the glass substrate, with a geometric thickness, in total, of between 5 and 150 nm, the functional layer consisting of said alloy, one or more upper layers for protection of the functional layer from atmospheric oxygen, said layer or layers having a geometric thickness, in total, of between 5 and 150 nm.

10. The glazing as claimed in claim 9, in which the lower and upper protective layer or layers are chosen from silicon nitride doped with Al, Zr, B, aluminum nitride AlN, tin oxide, a mixed zinc tin oxide Sn.sub.yZn.sub.zO.sub.x, silicon oxide SiO.sub.2, undoped titanium oxide TiO.sub.2 or silicon oxynitrides SiO.sub.xN.sub.y.

11. The glazing as claimed in claim 1, in which the stack comprises the sequence of the following layers, starting from the surface of the glass substrate: a lower layer with a thickness of between 5 and 150 nm, of silicon nitride optionally doped with Al, Zr, B or of aluminum nitride AlN, a functional layer consisting of said alloy, an upper layer with a thickness of between 5 and 150 nm, of silicon nitride doped with Al, Zr, B or of aluminum nitride AlN.

12. The glazing as claimed in claim 1, in which the stack comprises at least two functional layers consisting of said alloy comprising or consisting of nickel, of copper and of chromium, each of said layers being separated in the stack from the following layer by at least one intermediate layer of a dielectric material.

13. The glazing as claimed in claim 12, in which said intermediate layer comprises at least one layer of a material chosen from silicon nitride doped with Al, Zr, B, aluminum nitride AlN, tin oxide, a mixed zinc tin oxide Sn.sub.yZn.sub.zO.sub.x, silicon oxide SiO.sub.2, undoped titanium oxide TiO.sub.2 or silicon oxynitrides SiO.sub.xN.sub.y.

14. The glazing as claimed in claim 13, in which the stack comprises the sequence of the following layers, starting from the surface of the glass substrate: a lower layer with a thickness of between 5 and 150 nm, of silicon nitride doped with Al, Zr, B or of aluminum nitride AlN, a first functional layer essentially composed of said alloy comprising or essentially composed of nickel, of copper and of chromium, an intermediate layer with a thickness of between 5 and 150 nm comprising at least one layer of a material chosen from silicon nitride doped with Al, Zr, B, aluminum nitride AlN, tin oxide, a mixed zinc tin oxide Sn.sub.yZn.sub.zO.sub.x, silicon oxide SiO.sub.2, undoped titanium oxide TiO.sub.2 or silicon oxynitrides SiO.sub.xN.sub.y, doped silicon nitride, a second functional layer essentially composed of said alloy comprising or essentially composed of nickel, of copper and of chromium, an upper layer with a thickness of between 5 and 150 nm, of silicon nitride doped with Al, Zr, B or of aluminum nitride AlN.

15. The glazing as claimed in claim 1, in which the stack additionally comprises protective layers of a metal chosen from the group consisting of Ti, Mo and Al or of an alloy comprising at least one of these elements, or also protective layers of an alloy of nickel and of chromium, said layers being positioned in contact with and above and below the functional layer or layers, each protective layer having a geometric thickness of between approximately 1 nm and approximately 5 nm.

16. The glazing as claimed in claim 11, in which the thickness of the lower layer is between 30 and 70 nm, and the thickness of the upper layer is between 30 and 70 nm.

17. The glazing as claimed in claim 14, in which the thickness of the lower layer is between 30 and 70 nm, and the thickness of the upper layer is between 30 and 70 nm.

Description

EXAMPLE 1 (COMPARATIVE)

[0059] In this example in accordance with the application WO2013/057425, a stack consisting of the sequence of following layers:

TABLE-US-00001 Glass /Si.sub.3N.sub.4 /NiCr /Ni.sub.80Cu.sub.20* /NiCr /Si.sub.3N.sub.4 /TiO.sub.x (60 nm) (1 nm) (8 nm) (1 nm) (34 nm) (9 nm) *80 atom % of nickel, 20 atom % of copper

[0060] was deposited, according to conventional magnetron techniques, on a substrate made of glass of the Planilux type sold by the applicant company.

[0061] The layers of oxides and of nitrides are obtained according to the techniques of the art in the magnetron frame. The functional metal layer made of NiCu is obtained by the same magnetron sputtering technique from a target consisting of an alloy comprising approximately 80 atom % of nickel and approximately 20 atom % of copper. No difficulty was observed during the deposition of the layer by the magnetic-field-assisted (magnetron) sputtering techniques.

[0062] It was confirmed by Castaing microprobe analysis (also known as EPMA or electron probe microanalysis) that the composition of the metal layer finally obtained corresponds substantially to the composition of the initial target. More specifically, the composition of the alloy layer was measured beforehand by EPMA on a single layer deposited on the same substrate.

[0063] The substrate provided with its stack is subsequently subjected to a heat treatment consisting of a heating operation at 650 C. for ten minutes, followed by a tempering operation. This treatment is representative of the conditions undergone by the glazing if the latter has to be tempered.

[0064] The light transmittance factor T.sub.L and the normal emissivity before and after the heat treatment were measured in this comparative glazing according to the standards described above.

EXAMPLE 2 (ACCORDING TO THE INVENTION)

[0065] In this example according to the invention, the same stack as for example 1 is deposited on a glass substrate of the Planilux type, except that the functional layer is deposited by cosputtering from the target used in example 1 (80/20 atomic alloy of nickel and copper) and from an additional target made of chromium, in one and the same compartment of the magnetron device. The power applied to the two cathodes is adjusted in order to obtain a functional layer of nickel and of copper and of a small percentage of chromium.

[0066] The composition of the metal alloy layer is determined by Castaing microprobe analysis (also known as EPMA or electron probe microanalysis) according to the same principles as described above.

[0067] The stack deposited consists of the sequence of following layers:

TABLE-US-00002 Glass /Si.sub.3N.sub.4 /NiCr /Ni.sub.80Cu.sub.19Cr.sub.1* /NiCr /Si.sub.3N.sub.4 /TiO.sub.x (60 nm) (1 nm) (8 nm) (1 nm) (34 nm) (9 nm) *alloy consisting of 80 atom % of nickel, 19 atom % of copper and 1 atom % of chromium

[0068] No difficulty was observed during the deposition of the layer by the magnetron techniques, despite the high concentration of nickel in the alloy.

[0069] As for example 1, the substrate provided with its stack is subsequently subjected to a heat treatment consisting of a heating operation at 650 C. for ten minutes, followed by a tempering operation.

[0070] The light transmittance factor T.sub.L and the normal emissivity before and after the heat treatment are measured on this glazing according to the invention under the same conditions as above according to the standards described above.

EXAMPLE 3 (ACCORDING TO THE INVENTION)

[0071] In this example, a procedure identical to that of example 2 is carried out in order to obtain a substantially identical stack by the magnetron sputtering technique but the powers exerted on the two targets during the cosputtering are varied so as to increase the content of chromium in the alloy.

[0072] The composition of the metal alloy layer is determined by Castaing microprobe analysis as indicated above.

[0073] The stack deposited this time consists of the sequence of following layers:

TABLE-US-00003 Glass /Si.sub.3N.sub.4 /NiCr /Ni.sub.76Cu.sub.18Cr.sub.6* /NiCr /Si.sub.3N.sub.4 /TiO.sub.x (60 nm) (1 nm) (8 nm) (1 nm) (34 nm) (9 nm) *alloy consisting of 76 atom % of nickel, 18 atom % of copper and 6 atom % of chromium

[0074] As for example 1, the substrate provided with a stack is subsequently subjected to a heat treatment consisting of a heating operation at 650 C. for ten minutes, followed by a tempering operation.

[0075] The light transmittance factor T.sub.L and the normal emissivity before and after the heat treatment are measured on this glazing according to the invention under the same conditions as above according to the standards described above.

EXAMPLE 4 (ACCORDING TO THE INVENTION)

[0076] In this example, a procedure identical to that of example 3 is carried out in order to obtain a substantially identical stack by the magnetron sputtering technique but the power exerted on the target made of chromium during the cosputtering of the two targets is further increased, so as to further increase the chromium content in the alloy.

[0077] The composition of the metal alloy layer is also determined by Castaing microprobe analysis as indicated above.

[0078] The stack deposited this time consists of the sequence of following layers:

TABLE-US-00004 Glass /Si.sub.3N.sub.4 /NiCr /Ni.sub.73Cu.sub.17Cr.sub.10* /NiCr /Si.sub.3N.sub.4 /TiO.sub.x (60 nm) (1 nm) (8 nm) (1 nm) (34 nm) (9 nm) *alloy consisting of 73 atom % of nickel, 17 atom % of copper and 10 atom % of chromium

EXAMPLE 5 (COMPARATIVE)

[0079] In this example according to the invention, the same stack as for example 1 is deposited on a glass substrate of the Planilux type, except that the functional layer is deposited by cosputtering from the target used in example 1 (80/20 atomic alloy of nickel and of copper) and from a molybdenum target, in one and the same compartment of the magnetron device. The power applied to the two cathodes is adjusted in order to obtain a functional layer of nickel and of copper and of a small percentage of molybdenum.

[0080] The composition of the metal alloy layer is here again determined by Castaing microprobe analysis.

[0081] The stack deposited consists of the sequence of following layers:

TABLE-US-00005 Glass /Si.sub.3N.sub.4 /NiCr /Ni.sub.77Cu.sub.16Mo.sub.7* /NiCr /Si.sub.3N.sub.4 /TiO.sub.x (60 nm) (1 nm) (8 nm) (1 nm) (34 nm) (9 nm) *alloy consisting of 77 atom % of nickel, 16 atom % of copper and 7 atom % of molybdenum

[0082] As for the preceding examples, the substrate that is provided with a stack is subsequently subjected to a heat treatment consisting of a heating operation at 650 C. for ten minutes, followed by a tempering operation.

[0083] The light transmittance factor T.sub.L and the normal emissivity before and after the heat treatment are measured on this glazing according to the invention under the same conditions as above according to the standards described above.

The values of the measurements carried out on the samples according to examples 2 to 4 according to the invention and according to comparative examples 1 and 5 are combined in table 1 below:

TABLE-US-00006 TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Functional layer Ni.sub.80Cu.sub.20 Ni.sub.80Cu.sub.19Cr.sub.1 Ni.sub.76Cu.sub.18Cr.sub.6 Ni.sub.73Cu.sub.17Cr.sub.10 Ni.sub.75Cu.sub.16Mo.sub.9 Active layer 8 8 8 8 8 thickness (nm) T.sub.L (%) 52 52 51 50 49 after tempering .sub.n (%) 34 34 37 41 47 after tempering SF (solar factor) 48 47 47 47 46

[0084] The results given in table 1 above indicate that the main optical and thermal (solar control) properties do not vary substantially with the incorporation in the NiCu alloy of a minor amount of chromium.

[0085] In order to confirm the chemical resistances of the functional layers deposited according to the preceding examples, the resistance to acids of the glazings described above was measured by the SO.sub.2 test according to the conditions described in the standard EN1096-2 (January 2001), Annex C.

[0086] The normal emissivity of the stack is measured before beginning the test and then after 35 test cycles. A variation in the emissivity .sub.n is thus measured and is given in table 2 below as a percentage.

[0087] The variation in color of the glazing in transmission, on conclusion of the acid treatment (35 cycles), was quantified, in the L*, a*, b* colorimetric system and under normal incidence, by using the quantity E conventionally used in the L*, a*, b* international system and defined by the relationship:

E={square root over ((a*).sup.2+(b*).sup.2+(L*).sup.2)}

[0088] The measurements are carried out using a Minolta ISO 1175 spectrometer. The values of the measurements carried out on the different samples after the 35 cycles of the SO.sub.2 test are combined in table 2 below:

TABLE-US-00007 TABLE 2 Example 1 Example 2 Example 3 Example 4 Example 5* Functional layer Ni.sub.80Cu.sub.20 Ni.sub.80Cu.sub.19Cr.sub.1 Ni.sub.76Cu.sub.18Cr.sub.6 Ni.sub.73Cu.sub.17Cr.sub.10 Ni.sub.75Cu.sub.16Mo.sub.9 .sub.n (%) 1 0.6 0.2 0.2 5.2 E 2.7 1.6 0.9 1.1 8.1 *interrupted after 25 SO.sub.2 cycles

[0089] The preceding SO.sub.2 test of durability to acid attacks shows the superiority of the stacks according to the invention, comprising an alloy of nickel, of copper and of chromium. In particular, it is demonstrated the incorporation of chromium in the initial NiCu alloy makes it possible to considerably reduce the variations in emissivity and in coloration of the glazing in acid environments, making it possible to guarantee their initial properties over a long period, whatever the conditions of use, in particular externally.

The mechanical strength properties of the glazings provided with the stacks were measured on the samples of the preceding examples 1 to 5.
The test carried out is a Taber test on the thermally treated glazings of the preceding examples 1 to 4.

[0090] The Taber test measures the resistance to abrasion of the surface of the glazing on which the stack of layers has been deposited. A 5135 Abraser abrasion tester from Taber Industries subjects the coating to continuous rubbing using an abrasive disc. More specifically, an abrasive grinding wheel of CS10F grade is rotated, with application of a force of 4.9N (500 g), over the surface of the glazing to be evaluated. After 1000 revolutions, the glazings are recovered and the mechanical strength of the tested surface is evaluated by the variation of the light transmittance and the variation in the haze before and after the test.

The light transmittance is measured according to the standards described above.
The term haze, measured as a percentage, is understood to mean, within the meaning of the present invention, the loss by scattering of the light, that is to say, conventionally, the ratio of the scattered part of the light (diffuse fraction or T.sub.d) to the light directly transmitted through the glazing (T.sub.L), generally expressed as a percentage. The diffuse transmittance thus measures the light fraction scattered by the layer deposited at the surface of the glass substrate. The haze is conventionally measured by spectroscopy techniques, the integration over the whole of the visible region (380-780 nm) making it possible to determine the normal transmittance T.sub.L and the diffuse transmittance T.sub.d. Such a measurement is obtained by the use of a haze meter. The apparatus used is a Haze-Gard device sold by BYK-Gardner.
The results obtained are given in table 3 below:

TABLE-US-00008 TABLE 3 Taber 1000 cycles Example Functional layer T.sub.L Haze 1 Ni.sub.80Cu.sub.20 3.1 4.0 2 Ni.sub.80Cu.sub.19Cr.sub.1 2 5.8 3 Ni.sub.76Cu.sub.18Cr.sub.6 0.8 5.0 4 Ni.sub.73Cu.sub.17Cr.sub.10 0.5 3.9

[0091] The results given in table 3 above demonstrate the resistance to friction of the stacks according to the invention, in particular with regard to the reference stack according to example 1.