PANE-LIKE ARTICLE AND ITS USE, AND HOUSEHOLD APPLIANCE COMPRISING THE SAME

Abstract

The present disclosure relates to pane-like articles, such as glass or glass ceramic substrates, suited for microwave-shielding applications, such as microwave oven doors or covers for electronic components. The present disclosure further relates to a household appliance comprising a pane-like article.

Claims

1. A pane-like article comprising a pane-like substrate, wherein the substrate comprises a glass or a glass ceramic material, wherein in a portion of the pane-like article, the pane-like article has a reflectance of electromagnetic radiation in a wavelength range from 1.5 μm to 10 μm of about at least 10%, and a microwave leakage of less than 80 mW/cm.sup.2, preferably less than 50 mW/cm.sup.2, more preferably less 10 mW/cm.sup.2, and most preferably less than 5 mW/cm.sup.2.

2. The article according to claim 1, wherein in said portion of the pane-like article, the pane-like article has a transmittance of electromagnetic radiation in a wavelength range from 380 nm to 780 nm of about at least 10% for a thickness of the article and/or the substrate between about 3 mm and about 4 mm.

3. The article according to claim 1, wherein in said portion of the pane-like article, the pane-like article has an electrical resistivity of less than 50 ohms/cm.sup.2, preferably of less than 30 ohms/cm.sup.2.

4. The article according to claim 1, wherein in said portion of the pane-like article, the pane-like article has a thermal stability of at least 450° C.

5. The article according to claim 1, wherein in said portion of the pane-like article, the pane-like article has a dielectric constant ϵ.sub.r of greater than 15 at a frequency of 1 GHz.

6. The article according to claim 1, wherein in said portion of the pane-like article, the pane-like article has a dielectric loss, tan δ, of less than 0.0075 at a frequency of 1 GHz and preferably about at least 0.0024 and about at most 0.0075.

7. The article according to claim 1, comprising a layer in said portion of said pane-like article, wherein the layer is a contiguous layer.

8. The article according to claim 1, wherein the substrate comprises a glass or glass ceramic material having a dielectric constant ϵ.sub.r of greater than 15 at a frequency of 1 GHz and/or a dielectric loss, tan δ, of less than 0.0075 and preferably about at least 0.0024 and about at most 0.0075 at a frequency of 1 GHz.

9. The article according to claim 8, wherein the article comprises a layer arranged on at least one of the principal surface of the pane-like substrate at least partially so that the layer covers one of the principal surfaces of the substrate at least in a portion thereof, and wherein the layer is a metal layer, wherein preferably the thickness of the layer is between 5 nm and 50 nm.

10. The article according to claim 8, wherein the layer comprises a transparent conductive oxide.

11. The article according to claim 9, comprising a further layer, wherein said further layer comprises a transparent conductive oxide.

12. The article according to claim 1, wherein the article comprises a layer arranged on at least one of the principal surface of the pane-like substrate at least partially so that the layer covers one of the principal surfaces of the substrate at least in a portion thereof, and wherein the layer comprises a glass or glass ceramic material having a dielectric constant ϵ.sub.r of greater than 15 at a frequency of 1 GHz and/or a dielectric loss, tan δ, of less than 0.0075 and preferably about at least 0.0024 and about at most 0.0075 at a frequency of 1 GHz.

13. The article according to claim 12, wherein the layer comprises a non-dielectric flux and dielectric particles.

14. The article according to claim 12, wherein the layer comprises a dielectric flux and non-dielectric particles.

15. The article according to claim 12, wherein the article comprises a further layer, wherein said further layer is a metal layer.

16. The article according to claim 12, wherein the article comprises a further layer, wherein said further layer comprises a transparent conductive oxide.

17. The article according to claim 1, wherein the article comprises a layer arranged on at least one of the principal surface of the pane-like substrate at least partially so that the layer covers one of the principal surfaces of the substrate at least in a portion thereof, and wherein the layer is a metal layer and wherein the article has a dielectric constant, ϵ.sub.r, of greater than about 15 and preferably less than about 910, preferably about at least 15 and below about 150, at a frequency of 1 GHz and/or a dielectric loss, tan δ, of less than about 0.0075 and preferably more than about 0.0024 and less than about 0.0075 at a frequency of 1 GHz.

18. The article according to claim 17, wherein the metal layer comprises nickel and/or chromium.

19. The article according to claim 17, wherein the layer has a thickness between at least 5 nm and at most 50 nm.

20. The article according to claim 17, wherein the article comprises a further layer, said further layer comprising a transparent conductive oxide.

21. The article according to claim 17, wherein the substrate comprises a glass and/or glass ceramic material with a CTE of less than 4*10.sup.−6/K.

22. The article according to claim 1, wherein the article comprises a layer arranged on at least one of the principal surface of the pane-like substrate at least partially so that the layer covers one of the principal surfaces of the substrate at least in a portion thereof, and wherein the layer comprises a transparent conductive oxide, and wherein the article has a dielectric constant, E.sub.r, of greater than about 15 and preferably less than about 910, preferably about at least 15 and below about 150, at a frequency of 1 GHz and/or a dielectric loss, tan δ, of less than about 0.0075 and preferably more than about 0.0024 and less than about 0.0075 at a frequency of 1 GHz.

23. The article according to claim 22, wherein the transparent conductive oxide comprises SnO.sub.2.

24. The article according to claim 23, wherein the transparent conductive oxide comprises an undoped SnO.sub.2 and wherein the substrate comprises a glass or glass ceramic material with a thermal expansion coefficient of less than 4*10.sup.−6/K.

25. The article according to claim 23, wherein the SnO.sub.2 is a doped SnO.sub.2.

26. The article according to claim 25, wherein the dopant comprises Cu, Sb, Ni, or F, or mixtures thereof.

27. The article according to claim 25, wherein the layer comprises a copper-doped SnO.sub.2.

28. A household appliance, preferably a microwave oven, comprising a door comprising a pane-like article according to claim 1.

29. The household appliance according to claim 28, wherein the door is metal mesh free.

30. Use of the article according to claim 1 as electromagnetic shielding or as cover glass for LED.

Description

DESCRIPTION OF DRAWINGS

[0126] The invention will now be further explained with reference to the following drawings. In the drawing, like reference numerals refer to like or corresponding elements.

[0127] FIG. 1 is a schematic and not drawn to scale depiction of a household appliance.

[0128] FIGS. 2 and 3 are schematic and not drawn to scale depictions of pane-like articles.

[0129] FIG. 4 is a schematic and not drawn to scale depiction of a pane-like article for use as a cover glass for an LED device.

DETAILED DESCRIPTION

[0130] FIG. 1 shows in a schematic and not to scale depiction a household appliance 1. The household appliance 1 has a front side comprising a door comprising a pane-like article 2 according to embodiments of the present disclosure.

[0131] FIG. 2 is a schematic and not to scale depiction of a pane-like article 2 according to an embodiment of the invention in a side view. The pane-like article 2 comprises a substrate 20 comprising in a portion 201 of principal surface 200 a first layer 202 applied, in this case, directly onto the substrate material. Further, the pane-like article 2 comprises a further layer 203 applied, in this case, on top of the first layer 201. The further layer 203 may be applied so as to completely cover the first (or base) layer 202, or, as schematically depicted in FIG. 3, may be applied so that if covers only parts of the first layer 202 and may, at least in a portion thereof, even be applied directly upon the substrate material.

[0132] Preferably, in case the article 1 comprises two layers, the base layer 202 may be a layer comprising a TCO materials according to embodiments of the present disclosure, and the further layer 203 may be a metal layer according to embodiments of the present disclosure.

[0133] However, according to the disclosure, it is possible that the article comprises only one layer 202. In that case, the layer 202 preferably is a glass layer. The layer 202 may in that case comprises a glass flux material only, or the layer may comprise a glass flux as well as glass particles.

[0134] Further, according to an embodiment, the article may be layer free. In that case, the substrate material may comprise a glass material that imparts a reflectance of electromagnetic radiation in a wavelength range from 1.5 μm to 10 μm of about at least 10%, and/or a microwave leakage of less than 80 mW/cm.sup.2, preferably less than 50 mW/cm.sup.2, more preferably less 10 mW/cm.sup.2, and most preferably less than 5 mW/cm.sup.2 to the pane-like article. The microwave leakage is preferably determined at a wattage of at least 800 watts. Further, the microwave leakage may preferably be achieved for substrate and/or article thicknesses between at least 1 mm and at most 8 mm. For example a suitable glass material is listed in Tables 1 to 4 and 16.

[0135] FIG. 4 depicts schematically and not drawn to scale LED device 3 comprising housing 30 and LED 31. As part of housing 30, pane-like article 2 according to an embodiment may be used, for example as protective cover. For example, in that case pane-like article 2 may be configured to have a translucent, glass-based layer, preferably a layer according to the second aspect of the present invention, that is, a glass flux layer. In the schematic and not drawn to scale depiction in FIG. 4, pane-like article 2 comprises a first layer arranged on principal surface 201, wherein, in the case depicted in FIG. 4, the first layer is a glass flux first layer 2021. For example, in the special embodiment of FIG. 4, it may be contemplated that layer 2021 is a translucent layer with a haze of up to 150. The microwave leakage of layer 2021 may in that case be less than 80 mW/cm.sup.2, preferably less than 50 mW/cm.sup.2 and lower still, however, in the case depicted in FIG. 4, a very low microwave leakage need not be achieved. Rather, microwave leakage is set to be low enough so that LED functionality is not affected during 5 minutes with microwave power set to 900 watts. Further, it may be preferred that the coating is a hazy, translucent coating, so that the pane-like article may also act as an anti-dazzle filter.