A glass having a single-silver low-emissivity coating

Abstract

The invention relates to a Low-E coated glass comprising a glass substrate (10) and, on the glass substrate, a multilayer stack of coatings arranged for solar control. The Low-E coated glass comprises a single metallic layer (40) that is absorptive in the visible radiation spectrum and located within the interior of the stack, at least one dielectric layer (20), and at least one nucleation layer (30), wherein the ratio of the thickness of the dielectric layer (20) to the thickness of the nucleation layer (30) is in the range of 0,05 to 8,5, and the solar transmittance (%g) of the double glazing according to EN 410 is in the range of 27% to 62%.

Description

[0001] A GLASS HAVING A SINGLE-SILVER LOW-EMISSIVITY COATING

[0002] TECHNICAL FIELD

[0003] The present invention relates to a low-emissivity (Low-E) coating suitable for use on glass surfaces that provides solar control and thermal insulation for glass, has high heat-treatment resistance, and whose mechanical, physical, and optical properties can be tuned.

[0004] BACKGROUND ART

[0005] In the relevant technical field, glass used in the architectural and automotive sectors is coated with coating materials in order to improve its optical properties. In the glass industry there exist coating materials in many different forms and functions, and work to improve the properties of these materials is ongoing. Among the most widely used coating materials in the field are low- emissivity (Low-E) coatings. Such Low-E coatings contribute to fuel and energy savings by providing solar and thermal control (e.g., by reducing UV radiation by 70% or more). In addition, Low-E coatings confer transparency to the glass surface while also providing protection against cold weather. Low-E coatings comprise layers containing metals, oxides, and nitrides, each having different functions.

[0006] Single-silver Low-E coated glass technology has long been used in both the architectural and automotive industries to increase energy efficiency and provide thermal insulation. Low-E coatings consist of metallic or oxide materials applied to the glass surface in thin layers and, by reflecting infrared (IR) radiation, reduce heat losses while allowing a large portion of visible light to pass. In single-silver Low-E coatings, the basic structure generally places a reflective silver layer between supporting dielectric layers.

[0007] In the most basic known examples of such coatings, a single silver layer is used; this structure generally balances solar heat gains and optimizes heating and cooling costs for indoor spaces. A characteristic feature of single-silver Low-E coatings is that they can be produced by relatively low-cost processes and have a comparatively simple structure. Among existing examples of single-silver Low-E glass technology, a structure in which the silver layer is surrounded by protective dielectric layers is commonly used. These dielectric layers increase the coating’s resistance to oxidation while also optimizing light transmittance.

[0008] WO2023154023A1 relates to a low-emissivity (Low-E) coating for producing glass surfaces with improved environmental durability. According to that invention, the Low-E coating material is present on the glass surface and consists of layers obtained by sputtering metal, metal oxide, and / or metal nitride / oxynitride components under a magnetic field. If desired, after the glass surface is coated the Low-E coating may be subjected to heat treatment. Low-E coated glass surfaces according to that invention successfully pass the acid, humidity, and salt tests set out in TS EN 1096-2.

[0009] BRIEF SUMMARY OF THE INVENTION

[0010] The object of the invention is to provide a low-emissivity glass comprising a multilayer stack for solar control.

[0011] In order to achieve the above objective, the invention relates to a Low-E coated glass comprising a glass substrate and, on the glass substrate, a multilayer stack of coatings arranged for solar control. The Low-E coated glass comprises a single metallic layer that is absorptive in the visible radiation spectrum and located within the interior of the stack, at least one dielectric layer, and at least one protective layer, wherein the ratio of the thickness of the dielectric layer to the thickness of the protective layer is in the range of 0,05 to 8,5, and the solar transmittance (%g) of the double glazing according to EN 410 is in the range of 27% to 65%. In this manner, while reducing heat gain the glass also preserves transparency, rendering it suitable for both architectural and automotive applications.

[0012] In a preferred embodiment of the invention, the ratio of the total thickness of layers before the silver layer to the total thickness of layers after the silver layer is in the range of 0,32 to 1. This ratio regulates the function of the silver layer and its interaction with the other layers, thereby improving the glass’s solar reflectance, energy efficiency, and thermal insulation properties.

[0013] In a preferred embodiment, the dielectric layer comprises TiOx or SixNy. Thus, while preserving the transparency of the coating it provides solar control and increases the mechanical strength of the coating. At the same time, these materials allow optical tuning of the coating and improve the energy efficiency and long-term performance of Low-E coatings.

[0014] In a preferred embodiment, the thickness of the TiOx layer is in the range of 2 to 25 nm. In this way, the light reflectance values of the Low-E coated glass can be controlled.

[0015] In a preferred embodiment, the thickness of the SixNy layer is in the range of 6 to 22 nm. In this way, the Low-E coated glass exhibits high chemical resistance and high thermal durability.

[0016] In a preferred embodiment, the metallic layer comprises silver. Thus, by reflecting infrared radiation the thermal insulation properties of the Low-E coated glass are improved.

[0017] In a preferred embodiment, the thickness of the metallic layer is in the range of 10 to 20 nm. In this way, the Low-E coated glass reflects infrared radiation while increasing transmittance in the visible region.

[0018] In a preferred embodiment, the thickness of the ZnAlOx layer is in the range of 3 to 25 nm. In this way, the electrical conductivity of the Low-E glass is optimized and, at the same time, optical properties such as visible-region transmittance are improved.

[0019] In a preferred embodiment, the stack comprises, in order, at least one dielectric layer, at least one protective layer, a single metallic layer, at least one protective layer, and at least one dielectric layer. Accordingly, the first dielectric layer is used to increase light transmittance, reduce reflectance, and optimize optical properties, while the protective layers protect the metallic layer against environmental effects. When the metallic layer is formed of a material such as silver, it reflects infrared radiation and provides thermal insulation and energy efficiency. The second protective layer maintains the performance of the metallic layer, and the final dielectric layer controls transmittance at desired wavelengths to increase optical efficiency.

[0020] In a preferred embodiment, the daylight transmittance is in the range of 43% to 80%. Thus, the Low-E coated glass can be used in different applications in terms of both optical performance and energy savings. In a preferred embodiment, the external reflectance is in the range of 10% to 35%. In this way, the optical performance of the Low-E coated glass can be adjusted to desired reflectance levels, enabling its use in various applications.

[0021] In a preferred embodiment, the internal reflectance is in the range of 11% to 26%. In this way, the optical performance of the Low-E coated glass can be adjusted to desired reflectance levels, enabling its use in various applications.

[0022] In a preferred embodiment, the glass is blue in color. This allows it to be preferred for different uses.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 shows an example embodiment of the Low-E coated glass according to the invention.

[0025] DETAILED DESCRIPTION OF THE INVENTION

[0026] In this detailed description, the invention is explained without limitation and only for better understanding, with reference to examples.

[0027] Figure 1 shows an example embodiment of the Low-E coated glass according to the invention. A Low-E coating comprising a multilayer stack for solar control is formed on a glass substrate (10). A dielectric layer (20) is applied on the glass substrate (10). The dielectric layer (20) comprises SixNy or TiOx. The thickness of the dielectric layer (20) remains within the range of 2 to 25 nm. A nucleation layer (30) containing ZnAlOx is applied on the dielectric layer (20). The thickness of the nucleation layer (30) is in the range of 3 to 25 nm. A functional metallic layer (40), in particular a metallic layer (40) comprising silver, is applied on the nucleation layer (30). The thickness of the metallic layer (40) varies from 10 to 20 nm. At least one protective layer (50) is applied on the metallic layer (40). The protective layer (50) comprises ZnAlOx. The thickness of the protective layer is in the range of 2 to 25 nm. At least one second dielectric layer (60) is applied on the second protective layer (50). While the dielectric layer (20) is used to increase light transmittance, reduce reflectance, and optimize optical properties, the protective layer (50) protects the metallic layer (40) against environmental effects. When the metallic layer (40) is formed from a material such as silver, it reflects infrared radiation and provides thermal insulation and energy efficiency. While the protective layer (50) maintains the performance of the metallic layer (40), the second dielectric layer (60) controls transmittance at desired wavelengths, thereby increasing optical efficiency.

[0028] The coating materials and thickness values used in the examples are shown in the table above.

[0029] In Example 1 shown in the table, the glass substrate (10) is coated with an adjacent TiOx layer. The TiOx layer thickness is in the range of 2-25 nm. Adjacent to the TiOx layer, ZnAlOx is deposited. The ZnAlOx layer thickness is in the range of 3-25 nm. A silver layer is deposited on the ZnAlOx layer as a functional metallic layer. The silver layer thickness is in the range of 10-15 nm. The silver layer is then coated with ZnAlOx so as to form a second ZnAlOx layer. The thickness of the second ZnAlOx layer is in the range of 2-5 nm. The second ZnAlOx layer is then coated with TiOx so as to form a second TiOx layer. The thickness of the second TiOx layer is in the range of 5-15 nm. A ZnSnOx layer is obtained by depositing ZnSnOx on the second TiOx layer. The thickness of the ZnSnOx layer is in the range of 25-30 nm. SixNy is deposited on the ZnSnOx layer to form a SixNy layer. The thickness of the SixNy layer is in the range of 5-10 nm. When the optical properties of the Low-E coated glass having the Example-1 Low-E sequence were tested, the daylight transmittance was determined to be 77,8%. The external reflectance was determined to be 11 ,9%, and the internal reflectance 11 ,5%. The solar energy transmittance (%g) according to EN 410 was determined to be 56%. For the Low-E coated glass having the Example- 1 Low-E sequence, the thickness ratio between the nucleation layer (30) and the dielectric layer (20) was determined to be 0,12, and the ratio of the total thickness of layers prior to the silver layer to the total thickness of layers after the silver layer was determined to be 0,66. The Example-1 Low-E coated glass is blue in color. In Example 2 shown in the table, the glass substrate (10) is coated with an adjacent TiOx layer. The thickness of the TiOx layer is in the range of 2-25 nm. Adjacent to the TiOx layer, ZnAlOx is deposited. The thickness of the ZnAlOx layer is in the range of 3-25 nm. A silver layer is deposited on the ZnAlOx layer as a functional metallic layer. The silver layer thickness is in the range of 10-15 nm. The silver layer is then coated with ZnAlOx so as to form a second ZnAlOx layer. The thickness of the second ZnAlOx layer is in the range of 3-25 nm. The second ZnAlOx layer is then coated with TiOx so as to form a second TiOx layer. The thickness of the second TiOx layer is in the range of 10-20 nm. A ZnAlOx layer is obtained by depositing ZnAlOx on the second TiOx layer. The thickness of the ZnAlOx layer is in the range of 3-10 nm. SixNy is deposited on the ZnAlOx layer to form a SixNy layer. The thickness of the SixNy layer is in the range of 20-25 nm. When the optical properties of the Low-E coated glass having the Example-2 Low-E sequence were tested, the daylight transmittance was determined to be 77,8%. The external reflectance was determined to be 11 ,9%, and the internal reflectance 11 ,5%. The solar energy transmittance (%g) according to EN 410 was determined to be 61 ,8%. For the Low-E coated glass having the Example-2 Low-E sequence, the thickness ratio between the nucleation layer (30) and the dielectric layer (20) was determined to be 0,16, and the ratio of the total thickness of layers prior to the silver layer to the total thickness of layers after the silver layer was determined to be 0,67. The Example-2 Low-E coated glass is blue in color.

[0030] REFERENCE NUMERALS

[0031] 10 Glass Substrate

[0032] 20 Dielectric Layer 30 Nucleation Layer 40 Metallic Layer 50 Protective Layer 60 Second Dielectric Layer

Claims

CLAIMS1. A Low-E coated glass comprising a glass substrate (10) and, on the glass substrate, a multilayer stack of coatings arranged for solar control, characterized by a single metallic layer (40) that is absorptive in the visible radiation spectrum and located within the interior of the stack, at least one dielectric layer (20), and at least one nucleation layer (30), wherein the ratio of the thickness of the dielectric layer (20) to the thickness of the nucleation layer (30) is in the range of 0,05 to 8,5, and the solar transmittance (%g) of the double glazing according to EN 410 is in the range of 27% to 62%.

2. The glass according to claim 1 , wherein the ratio of the total thickness of layers before the silver layer to the total thickness of layers after the silver layer is in the range of 0,32 to 1.

3. The glass according to any of the preceding claims, wherein the dielectric layer (20) comprises TiOx or SixNy.

4. The glass according to claim 3, wherein the thickness of the TiOx layer is in the range of 2 to 25 nm.

5. The glass according to claim 3, wherein the thickness of the SixNy layer is in the range of 6 to 22 nm.

6. The glass according to any of the preceding claims, wherein the metallic layer (40) comprises silver.

7. The glass according to claim 6, wherein the thickness of the metallic layer (40) is in the range of 10 to 20 nm.

8. The glass according to any of the preceding claims, wherein the nucleation layer (30) comprises ZnAlOx.

9. The glass according to any of the preceding claims, wherein the thickness of the ZnAlOx layer is in the range of 3 to 25 nm.

10. The glass according to any of the preceding claims, further comprising sequentially at least one dielectric layer (20), at least one nucleation layer (30), a single metallic layer (40), at least one protective layer (50), and at least one second dielectric layer (60).11 . The glass according to any of the preceding claims, wherein the daylight transmittance is in the range of 43% to 80%.

12. The glass according to any of the preceding claims, wherein the external reflectance is in the range of 10% to 35%.

13. The glass according to any of the preceding claims, wherein the internal reflectance is in the range of 11 % to 26%.

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