TRANSPARENT SUBSTRATE WITH A MULTILAYER THIN FILM coating AND MULTYPLE GLAZING UNIT COMPRISING THE SAME

Abstract

A transparent substrate having a thin film multilayer coating according to one embodiment of the present invention comprises a plate glass having a tin surface, a first thin film multilayer coating formed on the tin surface, and a wrinkle-preventing layer formed between the tin surface and the first thin film multilayer coating and in direct contact with the tin surface, wherein the first thin film multilayer coating comprises an anti-oxidation layer located closest to the plate glass, at least one metal functional layer formed on the anti-oxidation layer and having an infrared reflection function, and an overcoat layer formed on the metal functional layer, wherein the wrinkle-preventing layer comprises a metal oxide comprising tin as a first metal and a second metal having a higher ionization tendency than tin.

Description

Technology Field

[0001] The present invention relates to a transparent substrate equipped with a thin film multilayer coating and a multi-glazing unit including the same. Specifically, the invention relates to a transparent substrate equipped with a thin film multilayer coating with improved durability without distinction between a tin surface and an air surface, and a multi-glazing unit including the same. Background Technology

[0002] Low-emissivity (Low-E) glass is glass in which a thin film of a low-emissivity layer containing a metal with high reflectivity in the infrared region, such as silver (Ag), is deposited. This low-emissivity glass is a functional material that brings about energy savings in buildings by reflecting infrared radiation; it blocks solar radiation from the outside into the inside during the summer and preserves heating radiation escaping from the inside to the outside during the winter. In glass, emissivity refers to the degree to which the glass reflects infrared energy of long wavelengths (2,500 to 40,000 nm). The lower the emissivity, the better the reflection, reflecting more infrared energy. Consequently, heat transfer is reduced, resulting in a lower thermal transmittance value and greater thermal insulation. For example, ordinary uncoated glass has an emissivity of approximately 0.84, but emissivity decreases as coating is applied. Glass with a low-emissivity coating layer can, for instance, have an emissivity of 0.10. Lower emissivity also results in a lower shading factor.

[0003] Meanwhile, coatings on low-emissivity glass generally consist of multiple layers, including a dielectric material layer. When such a coating is deposited on a transparent substrate (glass substrate), it reduces light reflection and increases transmission, thereby improving the visibility of objects behind the substrate.

[0004] These low-emissivity glasses are fabricated by depositing multilayer thin films onto plate glass through a sputtering process. The most common method in this plate glass production process is the float method, which involves melting the glass in a furnace and then floating the liquid glass over molten tin. Tin, upon which the liquid glass floats, is the optimal material because it has a low melting point (231.93°C) and a higher specific gravity than glass, allowing the molten glass to spread widely and reach equilibrium thickness. In the case of float glass produced through this process, a difference in composition occurs between the two sides; the side in contact with the molten tin is called the tin side, and the opposite side is called the air side. At the interface between the molten glass on the tin side and the molten tin, Fe within the glass components 2+ , Ca 2+ , Na+ and tin-like Sn 2+ Ion exchange occurs continuously. Consequently, tin ions of about 10 µm to 20 µm are diffused into the tin surface. Because of this, among the two sides of the commonly used plate glass, the air surface follows the glass composition, but the tin surface contains tin ions, so they actually have surfaces with different properties.

[0005] In the case of such tin surfaces, wettability is poor compared to air surfaces, and surfaces with poor wettability are difficult to clean, which increases the likelihood of residues remaining. Consequently, if a coating is applied to such surfaces, it is highly likely to cause adhesion problems between the surface and the coating. Therefore, since the probability of delamination increases when coating tin surfaces, low-emissivity coatings are also applied to air surfaces.

[0006] Furthermore, during heat treatments such as strengthening processes, the tin surface exhibits a bloom phenomenon in which fine irregularities are formed. This is due to the oxidation caused by heat treatment, which affects the Sn contained in the tin surface. 2+a. Sn acting as a former of the glass network 4+ This phenomenon occurs because it is converted. Consequently, the physical properties of the glass on the tin surface differ from those of the air surface. In particular, during heat treatment, differences in residual stress arise due to the difference in thermoelasticity between the interior of the glass and the surface of the tin, and this phenomenon manifests as fine wrinkles on the surface. Such surface irregularities can cause clouding issues, where the glass becomes hazy when a coating is formed on top, and can lead to coating defects. Specifically, when applying low-emissivity coatings using functional metals such as silver (Ag) to the tin surface, white dot defects occur due to the reaction between silver and Sn during the heat treatment process, which can cause serious quality issues. Therefore, coating on the tin surface of plate glass is limited, and it is common practice to apply it to the air surface.

[0007] In architectural window glass, low-emissivity coated glass is used to improve thermal insulation performance. In particular, to maximize insulation performance and block heat conduction, double-glazed systems have been introduced. To further enhance this, triple-glazed, double-pane, or vacuum double-glazed glass systems utilizing three panes of glass are being utilized. As such, using multiple panes of low-emissivity coated glass in double-glazed windows maximizes insulation performance; recently, the application of two or more panes of low-emissivity coated glass in triple-glazed and double-pane windows has become common practice. Particularly in cold climates where heating loads exceed cooling loads, or during winters when temperatures drop sharply, securing insulation performance while simultaneously achieving high solar heat gain during the day is crucial for saving heating energy and ensuring thermal comfort. However, while applying multiple panes of low-emissivity coated glass can improve insulation performance, it may actually reduce solar heat gain. Conversely, applying low-emissivity coated glass to both sides can yield higher solar heat gain at the same level of insulation performance. Furthermore, if coatings with different functions can be applied to both sides of a single pane of glass in addition to the low-emissivity coating, it presents an opportunity to expand the glass's performance capabilities. Despite the advantages of such double-sided coated glass, as previously explained, the quality of the coating deteriorates significantly on the tin side of the glass sheet; consequently, the current practice involves using multiple sheets of single-sided coated glass with the coating formed only on the air side. Therefore, there is a need for the development of technology that can form a good coating on the tin side without compromising coating quality. The problem to be solved

[0008] The present invention aims to solve these problems by providing a transparent substrate including a thin film multilayer coating that enables coating even on tin surfaces where problems occur during coating and heat treatment, and further enables the coating quality to be at the same level as that of air surfaces, and a multi-glazing unit including the same.

[0009] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention. means of solving the problem

[0010] A transparent substrate having a thin film multilayer coating according to one embodiment of the present invention comprises a plate glass having a tin surface, a first thin film multilayer coating formed on the tin surface, and a wrinkle-preventing layer formed between the tin surface and the first thin film multilayer coating and in direct contact with the tin surface, wherein the first thin film multilayer coating comprises an anti-oxidation layer located closest to the plate glass, at least one metal functional layer formed on the anti-oxidation layer and having an infrared reflection function, and an overcoat layer formed on the metal functional layer, wherein the wrinkle-preventing layer comprises a metal oxide comprising tin as a first metal and a second metal having a higher ionization tendency than tin.

[0011] The second metal mentioned above may be at least one selected from zinc, magnesium, and aluminum.

[0012] The above metal oxide may be tin-zinc oxide (SnZnO).

[0013] The thickness of the above anti-wrinkle layer may be 15 nm to 40 nm.

[0014] The molar ratio of the second metal to the first metal may be 0.7 to 1.3.

[0015] The above-mentioned antioxidant layer can be in direct contact with the above-mentioned anti-wrinkle layer.

[0016] The above-mentioned antioxidant layer may include Si3N4.

[0017] The device further includes a lower metal protective layer formed below the metal functional layer and an upper metal protective layer disposed above the metal functional layer, wherein each of the lower metal protective layer and the upper metal protective layer may include NiCr.

[0018] It may further include an anti-reflection layer comprising Si3N4 disposed between the metal functional layer and the overcoat layer.

[0019] The above at least one metal functional layer comprises a first metal functional layer and a second metal functional layer, and may further include a first anti-reflection layer disposed between the first metal functional layer and the second metal functional layer and a second anti-reflection layer disposed on the second metal functional layer.

[0020] The first anti-reflection layer and the second anti-reflection layer may include Si3N4.

[0021] The above overcoat layer may comprise one or more selected from zirconium-doped titanium oxide, zirconium oxide, zirconium-doped titanium oxynitride, or zirconium oxynitride.

[0022] The above-mentioned glass plate may include an air surface located on the opposite side of the tin surface and may further include a second thin film multilayer coating formed on the air surface.

[0023] The anti-wrinkle layer may not be formed on the air surface mentioned above.

[0024] The above transparent substrate may be heat-treated in a state where the anti-wrinkle layer and the first thin film multilayer coating are formed on the tin surface of the above plate glass.

[0025] A multi-glazing unit according to one embodiment of the present invention is a multi-glazing unit comprising two or more transparent substrates spaced apart from each other with a spacer in between, wherein at least one of the two or more transparent substrates is a transparent substrate having the aforementioned thin film multilayer coating.

[0026] One of the above two or more transparent substrates is a transparent substrate having a thin film multilayer coating that further includes a second thin film multilayer coating formed on the air surface, and the other of the above two or more transparent substrates may be a plate glass that does not have a thin film multilayer coating.

[0027] A transparent substrate equipped with a thin film multilayer coating, further comprising a second thin film multilayer coating formed on the air surface, can be placed on the indoor side. Effects of the invention

[0028] According to one embodiment of the present invention, a transparent substrate having a thin film multilayer coating having excellent durability without wrinkles even on a tin surface can be provided. Brief explanation of the drawing

[0029] FIG. 1 is a cross-sectional view of a transparent substrate having a thin film multilayer coating according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of a transparent substrate having a thin film multilayer coating according to another embodiment of the present invention. FIG. 3 is a cross-sectional view of a transparent substrate having a thin film multilayer coating according to another embodiment of the present invention. FIG. 4 is a cross-sectional view of a multi-glazing unit according to one embodiment of the present invention. FIG. 5 is a figure showing the results of measuring roughness for Example 1 and Comparative Example 2. FIG. 6 is a diagram showing the results of a scratch evaluation performed on Example 1 and Comparative Example 2 and a photograph of the scratched area. Figure 7 is a diagram showing the results of microscopic observation after evaluating moisture resistance for Example 1 and Comparative Example 2. Specific details for implementing the invention

[0030] All technical and scientific terms used in this specification have the meaning generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. All terms used in this specification are selected for the purpose of further explaining the present invention and are not selected to limit the scope of the rights of the present invention.

[0031] Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited thereto. These terms are used solely to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, the first part, component, region, layer, or section described below may be referred to as the second part, component, region, layer, or section without departing from the scope of the present invention.

[0032] The technical terms used herein are for the reference of specific embodiments only and are not intended to limit the invention. The singular forms used herein include plural forms unless phrases clearly indicate otherwise. As used in the specification, the meaning of "comprising" specifies certain characteristics, areas, integers, steps, actions, elements, and / or components, and does not exclude the presence or addition of other characteristics, areas, integers, steps, actions, elements, and / or components.

[0033] When it is stated that one part is "above" or "on" another part, it may be directly above or on the other part, or other parts may be involved in between. In contrast, when it is stated that one part is "directly above" another part, no other parts are interposed in between.

[0034] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined.

[0035] In this invention, the terms "emissivity" and "transmittance" are used as commonly known in the art. "Emissivity" is a measure indicating how much light at a given wavelength is absorbed and reflected. Generally, it satisfies the following equation.

[0036] (Emissivity) = 1 - (Reflectivity)

[0037] For architectural purposes, the emissivity value of approximately 2500–50000 nm in the infrared spectrum is important.

[0038] In this specification, the term "transmittance" means visible light transmittance.

[0039] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined.

[0040] Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0041] FIG. 1 is a cross-sectional view of a transparent substrate (1000) having a thin film multilayer coating according to an embodiment of the present invention. The transparent substrate (1000) having a thin film multilayer coating of FIG. 1 is merely for illustrating the present invention and is not limited thereto. Accordingly, the transparent substrate (1000) having a thin film multilayer coating of FIG. 1 can be modified into various forms.

[0042] Referring to FIG. 1, a transparent substrate (1000) having a thin film multilayer coating according to one embodiment of the present invention comprises a plate glass (100), a first thin film multilayer coating (210) formed on the plate glass (100), and a wrinkle-preventing layer (200) formed between the first thin film multilayer coating (210) and the plate glass (100).

[0043] Plate glass (100) may be glass made of hard inorganic material or organic material based on a polymer, although it is not specifically limited. Plate glass (100) may be glass formed by a float method. That is, it may be glass formed by a method in which raw materials are melted in a furnace and then liquid glass is floated on molten tin. Accordingly, when plate glass (100) is manufactured by the float method, it includes a tin surface (101) in contact with molten tin and an air surface (102) which is the opposite side of the tin surface (101).

[0044] The first thin film multilayer coating (210) is formed in a structure in which a plurality of thin film layers are stacked on the plate glass (100) to impart various optical and chemical properties. This first thin film multilayer coating (210) can be formed by depositing it on the plate glass (100) using a physical vapor deposition (PVD) process, such as a sputtering process.

[0045] Between the first thin film multilayer coating (210) and the tin surface (101) of the plate glass (100), a wrinkle prevention layer (200) in direct contact with the tin surface (101) is formed. By forming the wrinkle prevention layer (200), even if the first thin film multilayer coating (210) is formed on the tin surface (101) and heat treatment is performed, an excellent coating with good adhesion and the ability to prevent unevenness can be obtained. The specific composition of this wrinkle prevention layer (200) will be described later.

[0046] The first thin film multilayer coating (210) includes an anti-oxidation layer (10) located closest to the plate glass (100), at least one metal functional layer (30) formed on the anti-oxidation layer (10) and having an infrared reflection function, and an overcoat layer (60) formed on the metal functional layer (30). In this embodiment, each layer is described with an example configuration including one metal functional layer (30).

[0047] The anti-oxidation layer (10) includes at least one dielectric layer. The dielectric layer may include a metal oxide, a metal nitride, or a metal oxynitride. The metal may include one or more of titanium (Ti), hafnium (Hf), zirconium (Zr), zinc (Zn), indium (In), tin (Sn), and silicon (Si).

[0048] The anti-oxidation layer (10) may be a single layer or may be formed as a laminate of two or more layers. The anti-oxidation layer (10) may be formed in direct contact with the anti-wrinkle layer (200) and may prevent oxidation of the metal functional layer (30). That is, by forming the anti-oxidation layer (10) between the anti-wrinkle layer (200) and the metal functional layer (30), excess oxygen may be prevented from oxidizing the metal functional layer (30). To this end, the anti-oxidation layer (10) may preferably include silicon nitride (Si3N4). In addition, the thickness of the anti-oxidation layer (10) may be 10 nm to 50 nm.

[0049] Meanwhile, the upper portion of the metal functional layer (30) may further include an anti-reflection layer (50). The anti-reflection layer (50) includes at least one dielectric layer. The dielectric layer may include a metal oxide, a metal nitride, or a metal oxynitride. The metal may include one or more of titanium (Ti), hafnium (Hf), zirconium (Zr), zinc (Zn), indium (In), tin (Sn), and silicon (Si). Preferably, the anti-reflection layer (50) may include silicon nitride (Si3N4). Additionally, as shown in FIG. 1, it may be formed as a single layer or as a laminate of two or more layers, and is not particularly limited. The thickness of the anti-reflection layer (50) may be 5 nm to 15 nm. Furthermore, the anti-reflection layer (50) may be additionally doped with aluminum, etc. By doping with aluminum, the dielectric layer can be smoothly formed during the manufacturing process. In addition, various doping agents, such as fluorine, carbon, nitrogen, boron, and phosphorus, can be used in addition to zirconium and aluminum to improve not only the optical properties of the film but also the rate of formation of the dielectric layer by sputtering.

[0050] The metal functional layer (30) has infrared (IR) reflection properties. The metal functional layer (30) may include one or more of gold (Ag), copper (Cu), palladium (Pd), aluminum (Al), and silver (Ag). Specifically, it may include silver or a silver alloy. Silver alloys may include a silver-gold alloy or a silver-palladium alloy. The thickness of the metal functional layer (30) may be 7 nm to 18 nm, and more preferably 12 nm to 15 nm. If the thickness is too thin, the solar heat gain coefficient (SHGC) may increase. If the thickness is too thick, the color coordinates of the transmitted color may move away from blue.

[0051] A lower metal protective layer (20) and an upper metal protective layer (40) may be further formed on the lower surface and the upper surface, respectively, of the metal functional layer (30). That is, the lower metal protective layer (20) located between the anti-oxidation layer (10) and the metal functional layer (30), and the upper metal protective layer (40) located between the anti-reflection layer (50) and the metal functional layer (30) are included. The lower metal protective layer (20) and the upper metal protective layer (40) can prevent the metal functional layer (30) from oxidizing or corroding. For example, the lower metal protective layer (20) and the upper metal protective layer (40) can perform the function of preventing oxygen from entering the functional layer and damaging the functional layer during a deposition process or a heat treatment process. These lower metal protective layer (20) and upper metal protective layer (40) may be configured to be formed in direct contact with the lower surface and the upper surface, respectively, of the metal functional layer (30).

[0052] Meanwhile, to maximize the anti-oxidation effect, the thickness of the lower metal protective layer (20) and the upper metal protective layer (40) may be increased, but this is not desirable because the transmittance of the transparent substrate (1000) equipped with the thin film multilayer coating decreases and the emissivity increases. Accordingly, in one embodiment of the present invention, the thickness of the lower metal protective layer (20) may be 0.5 nm to 1.5 nm, and the thickness of the upper metal protective layer (40) may be 0.5 nm to 1.5 nm. The lower metal protective layer (20) and the upper metal protective layer (40) may each include one or more of titanium, nickel, chromium, and niobium. More specifically, they may include a nickel-chromium alloy (NiCr).

[0053] Additionally, the uppermost portion of the first thin film multilayer coating (210) may include an overcoat layer (60). That is, the overcoat layer (60) is included on the upper portion of the upper anti-reflection layer (50), i.e., on one side away from the plate glass (100). The overcoat layer (60) may include one or more selected from titanium oxide (TiO), titanium nitride (TiN), titanium oxynitride (TiON), zirconium oxide (ZrO), zirconium nitride (ZrN), zirconium oxynitride (ZrON), and titanium-zirconium oxides, nitrides, and oxynitrides.

[0054] By including such an overcoat layer (60), damage to the layers included in the first thin film multilayer coating (210) can be prevented. The thickness of the overcoat layer (60) may be 1 nm to 5 nm, preferably 1 nm to 3 nm.

[0055] In order to ensure that this first thin film multilayer coating (210) is formed well on the tin surface (101) and coated with excellent quality, a wrinkle-preventing layer (200) is formed between the first thin film multilayer coating (210) and the tin surface (101). When forming a coating on the tin surface (101), wrinkles occur because Sn present on the tin surface diffuses onto the surface when the tin surface (101) is heat-treated. 2+ This Sn 4+ As it oxidizes, the difference in thermoelasticity can be seen as the cause. In other words, wrinkles occur because the viscosity decreases and the thermal expansion increases compared to conventional glass. Accordingly, by forming a wrinkle-preventing layer (200) by mixing a metal element with a higher ionization tendency than tin into an oxide (SnO2) containing tin, the oxidation of tin ions contained in the tin surface can be prevented, thereby suppressing the occurrence of wrinkles.

[0056] Accordingly, the anti-wrinkle layer (200) may include a metal oxide comprising tin as a first metal and, in addition, a second metal having a higher ionization tendency than tin. Here, at least one selected from zinc, magnesium, and aluminum may be applied as the second metal. Preferably, the metal oxide may be tin-zinc oxide (SnZnO). Also, at this time, the molar ratio of the second metal to the first metal may be 0.7 to 1.3. If the value is less than 0.7, the Zn content is insufficient and wrinkles may occur during the heat treatment process, and if it is greater than 1.3, chemical resistance or moisture resistance deteriorates and is undesirable.

[0057] Meanwhile, the thickness of the anti-wrinkle layer (200) may be 15 nm to 40 nm. If the thickness of the anti-wrinkle layer (200) is too thin, the effect of preventing wrinkles cannot be sufficiently obtained, and if the thickness of the anti-wrinkle layer is too thick, the peeling or moisture resistance of the coating surface is reduced, which is undesirable.

[0058] This anti-wrinkle layer (200) is formed in direct contact with the tin surface (101) at the bottom. By being formed in this way, the oxidation of tin ions inside the tin surface (101) is prevented, thereby preventing the occurrence of wrinkles. Additionally, an anti-oxidation layer (10) is formed in direct contact with the upper surface of the anti-wrinkle layer (200). Through this, the oxidation of the metal functional layer (30) can be prevented. That is, if there is no anti-oxidation layer (10), the metal functional layer (Ag) may oxidize due to the metal oxide of the anti-wrinkle layer (200), which can reduce the durability of the coating film; however, by forming the anti-oxidation layer (10), the excess oxygen of the anti-wrinkle layer (200) can be prevented from oxidizing the functional layer.

[0059] Meanwhile, in addition to the layer shown in the drawing, the first thin film multilayer coating (210) may further include various functional layers to improve the quality of the coating layer, such as a wetting layer to improve interlayer adhesion, or a stress relief layer to alleviate the difference in interlayer stress in a multilayer structure, and is not particularly limited.

[0060] As described above, according to one embodiment of the present invention, by providing a wrinkle prevention layer (200) between the first thin film multilayer coating (210) and the tin surface (101), a thin film multilayer coating with excellent durability and reduced wrinkle occurrence can be formed on the tin surface (101) of the plate glass (100).

[0061] Next, with reference to FIG. 2, a transparent substrate having a thin film multilayer coating according to another embodiment of the present invention will be described.

[0062] FIG. 2 is a cross-sectional view of a transparent substrate having a thin film multilayer coating according to another embodiment of the present invention.

[0063] Referring to FIG. 2, in the case of a transparent substrate (1001) equipped with a thin film multilayer coating according to another embodiment of the present invention, there is a difference from the previously described embodiment in that it further includes a second metal functional layer (31) in addition to the metal functional layer (30) provided in the first thin film multilayer coating (211), and the resulting additional laminated structure, while the remaining configuration is the same. Therefore, only the configuration that differs will be described.

[0064] First, as illustrated in FIG. 2, the first thin film multilayer coating (211) may include two metal functional layers, a first metal functional layer (30) and a second metal functional layer (31). However, it is not limited thereto, and additional metal functional layers (30, 31) may be added and are not specifically limited. The composition and characteristics of the first and second metal functional layers (30, 31) are the same as those of the metal functional layers described above, so they are omitted.

[0065] Below the first metal functional layer (30), a wrinkle-prevention layer (200), an oxidation-prevention layer (10), and a lower metal protective layer (20) are sequentially arranged in the same manner as in the previous embodiment, and above, an upper metal protective layer (40) and an anti-reflection layer (50) are sequentially arranged in the same manner as in the previous embodiment.

[0066] A second metal functional layer (31) is disposed on top of the anti-reflection layer (50). At this time, to protect the second metal functional layer (31), a second lower metal protective layer (21) and a second upper metal protective layer (41) are disposed on the lower and upper sides, respectively, of the second metal functional layer (31). The characteristics of these second lower metal protective layer (21) and second upper metal protective layer (41) are the same as those of the upper metal protective layer (40) and lower metal protective layer (20) disposed on the upper and lower sides of the first metal functional layer (30).

[0067] Additionally, a second anti-reflection layer (51) may be disposed on the second upper metal protective layer (41), and since the characteristics of the layer are the same as the characteristics of the anti-reflection layer (50), it is omitted. However, when actually forming each layer, the composition and components of each layer may be the same or different from each other and are not particularly limited.

[0068] Next, with reference to FIG. 3, a transparent substrate equipped with a thin film multilayer coating according to another embodiment of the present invention will be described.

[0069] FIG. 3 is a cross-sectional view of a transparent substrate having a thin film multilayer coating according to another embodiment of the present invention.

[0070] Referring to FIG. 3, in the case of a transparent substrate (1002) equipped with a thin film multilayer coating according to another embodiment of the present invention, compared with the previously described embodiment, the thin film multilayer coating is formed not only on the tin surface (101) but also on the air surface (102), and the remaining configuration is the same, so only the configuration that differs will be described.

[0071] As illustrated in FIG. 3, a transparent substrate (1002) having a thin film multilayer coating according to another embodiment of the present invention further includes a second thin film multilayer coating (220) formed on an air surface (102) in addition to a first thin film multilayer coating (210) formed on a tin surface (101).

[0072] The detailed layer composition of the first and second thin film multilayer coatings (210, 220) is the same as that of the thin film multilayer coating described above, and is schematically illustrated as a single layer. That is, a transparent substrate (1002) is obtained by forming a low-emissivity coating layer containing at least one metal functional layer on both the tin surface (101) and the air surface (102) of a plate glass (100). At this time, the tin surface (101) further includes a wrinkle-prevention layer (200) on the lower part of the first thin film multilayer coating (210) in contact with the tin surface (101). In the case of the air surface (102), since there is no degradation in coating quality, the second thin film multilayer coating (220) is formed directly on the air surface (102) without forming the wrinkle-prevention layer (200).

[0073] In the case of the transparent substrate (1002) equipped with the thin film multilayer coating obtained in this way, since both sides of a single plate glass (100) are equipped with low-emissivity coating layers, improved low-emissivity performance can be obtained, and at the same time, excellent coating quality can be obtained for the coating layer formed on the tin surface (101), so that a double-sided coated glass with excellent durability and coating quality can be obtained.

[0074] FIG. 4 is a cross-sectional view of a multi-glazing unit (2000) according to one embodiment of the present invention.

[0075] The multi-glazing unit (2000) of FIG. 4 is merely for illustrating the present invention and is not limited thereto. Accordingly, the multi-glazing unit (2000) of FIG. 4 can be modified in various forms.

[0076] As illustrated in FIG. 4, a multi-glazing unit (2000) according to one embodiment of the present invention is a multi-glazing unit (2000) comprising two glass plates (100) spaced apart from each other. That is, the multi-glazing unit (2000) comprises two or more transparent substrates held by a spacer (500), and one or more gas separation interfaces (300) are disposed between the two substrates. At this time, at least one of the two glass plates (100) is provided with the aforementioned first thin film multilayer coating (210). In particular, as illustrated in FIG. 4, a second thin film multilayer coating (220) is formed on one side of the glass plate (100) disposed on the indoor side, and by applying a double-sided coated transparent substrate having a wrinkle-prevention layer (200) and a first thin film multilayer coating (210) formed on the other side, the thermal insulation performance can be improved with two low-emissivity coating layers, and the solar heat gain rate can also be improved. In addition, by placing double-sided coated glass on the interior side, exposure to the external environment that could reduce the lifespan of the coating layer can be minimized.

[0077] In FIG. 4, it is shown that no separate thin film is formed on the transparent substrate other than the indoor side transparent substrate equipped with the first thin film multilayer coating (210) and the second thin film multilayer coating (220); however, a thin film multilayer coating may be formed on the upper surface, the lower surface, or both surfaces, and it is also possible to form a thin film different from this. In particular, according to the present embodiment, a coating layer can be formed by providing a wrinkle-prevention layer on the tin surface as well, so that coating layers of various functions can be designed as needed and appropriately formed on each surface of the transparent substrate.

[0078] The present invention will be explained in more detail below through experimental examples. However, these experimental examples are merely for illustrating the present invention and are not limited thereto.

[0080] Experimental Example

[0081] - Manufacturing example

[0082] Examples 1 and 2 and Comparative Example 2 were prepared by forming a thin film multilayer coating containing a laminated structure and materials as shown in Table 1 on a transparent substrate. A 5 mm thick glass substrate (product name: Hanlight Clear, manufactured by Hankook Glass Industry Co., Ltd.) was used as the transparent substrate. In each glass substrate, the surface on which the thin film multilayer coating was formed was an air surface only in Comparative Example 1, and was formed on a tin surface in the remaining Examples 1 and 2 and Comparative Examples 2 to 5.

[0083] ingredient Comparative Example 1 [nm] Comparative Example 2 [nm] Comparative Example 3 [nm] Comparative Example 4 [nm] Comparative Example 5 [nm] Example 1 [nm] Example 2 [nm] Overcoat layer TiZrO 2 2 2 2 2 2 2 Second anti-reflective layer Si3N4 40 moist layer ZnO 5 Second upper metal protective layer NiCr 1 Second metal functional layer Ag 20 Second lower metal protective layer NiCr 1 moist layer ZnO 5 Anti-reflective layer Si3N4 40 40 40 40 40 40 70 moist layer ZnO 5 5 5 5 5 5 5 Upper metal protective layer NiCr 1 1 1 1 1 1 1 First metal functional layer Ag 15 15 15 15 15 15 15 Lower metal protective layer NiCr 1 1 1 1 1 1 1 moist layer ZnO 5 5 5 5 5 5 5 Antioxidant layer Si3N4 35 35 30 0 5 15 15 Anti-wrinkle layer SnZnO(Sn:Zn=1:1) 0 0 5 35 30 20 30 Plate glass (surface with a coating layer) glass substrate (5mm) air surface Commentary Commentary Commentary Commentary Commentary Commentary

[0084] For the transparent substrates of the above examples and comparative examples, heat treatment was performed at 700°C for 10 minutes, and then the following evaluation was conducted.

[0086] - Evaluation 1: Surface Wrinkle Evaluation

[0087] Measuring device: Atomic Force Microscopy (AFM), Parksystem XE100

[0088] Measurement area: 20x20um 3 point average

[0089] Measurement method: The surface wrinkling phenomenon was quantified by measuring the roughness of the measurement area. The measured roughness values ​​are listed in Table 2.

[0090] In addition, the results of measuring the roughness of Example 1 and Comparative Example 2 using AFM are shown in FIG. 5. As shown in FIG. 5, it was confirmed that in Example 1, despite being a tin surface coating, the wrinkle shape was minimal.

[0092] -Evaluation 2: Number of surface defects

[0093] Measuring device: Atomic Force Microscopy (AFM), Parksystem XE100

[0094] Measurement area: 20x20um 3 point average

[0095] Measurement method: The number of defects, such as micron-sized pinholes, occurring within the measurement area was measured. The number of measured defects is listed in Table 2.

[0097] - Evaluation 3: Haze Evaluation

[0098] Measuring device: Haze meter Product name KTH 100

[0099] The results measured using a haze meter are listed in Table 2. The haze value represents the phenomenon of refraction of transmitted light caused by surface wrinkles and surface defects, and a higher haze value indicates that there are more surface wrinkles and surface defects.

[0101] - Evaluation 4: White spot defect evaluation

[0102] Measurement method: The total number of defects with a diameter of 0.5 mm or more within a 30x30 cm area was counted. The results are listed in Table 2.

[0104] - Evaluation 5: Coating peeling evaluation (scratch evaluation)

[0105] Measurement method: Using an Ericshen scratch tester, the scratch width generated after applying 5N to the surface was measured. The results are shown in Table 2.

[0106] In addition, a scratch evaluation was performed on Example 1 and Comparative Example 2, and the results of photographing the scratched parts are shown in FIG. 6. As shown in FIG. 6, it was confirmed that Example 1 has excellent scratch resistance even though a coating layer was formed on the tin surface.

[0108] - Evaluation 6: Moisture Resistance Evaluation

[0109] Measurement method: The condition was observed after aging for 120 hours in an environment of 40℃ and RH 100%. At this time, the color difference was measured, and the condition was observed under a microscope.

[0110] Color difference measurement: The color difference (L*a*b*) of the coating surface reflection before and after aging was measured.

[0111] Microscope: Observed at 50x magnification.

[0112] The color difference measurements are listed in Table 1. In addition, the results of microscopic observation of Example 1 and Comparative Example 2 are shown in Figure 7. As shown in Figure 7, in the case of Example 1, surface defects hardly occurred even in a high-temperature and high-humidity environment for a long time, confirming that long-term durability and moisture resistance are also excellent.

[0114] The results of the above evaluations 1 to 6 are shown in Table 2 below.

[0115] characteristic unit Comparative Example 1 [nm] Comparative Example 2 [nm] Comparative Example 3 [nm] Comparative Example 4 [nm] Comparative Example 5 [nm] Example 1 [nm] Example 2 [nm] Surface wrinkles [Ra] nm 0.5 4.4 3.5 3.0 0.7 0.6 0.8 Number of surface defects Dog [20x20um] 0 16 9 4 0 0 0 Haze % 0 5 2.5 1.5 0 0 5 white spot defect Dog [30x30cm] 5 135 53 20 15 4 11 Coating peeling [scratch test] um 21 56 48 63 40 16 35 Moisture resistance [color difference] ΔE 0.5 2.5 1.0 3.2 3.5 0.8 0.5

[0116] As shown in Table 2 above, it was confirmed that in the case of Example 1, even though a coating was formed on the tin surface, it exhibited characteristics that were nearly equivalent to or superior to Comparative Example 1, in which a coating was formed on the air surface. In addition, it was confirmed that in the case of Example 2, in which a thick coating layer including two metal functional layers was formed on the tin surface, generally good characteristics were exhibited. On the other hand, in the case where a wrinkle-prevention layer is included but an oxidation-prevention layer is not formed, it was confirmed that the peeling characteristics were particularly poor, as in Comparative Example 4.

[0117] Based on the comprehensive evaluation results above, it was confirmed that according to the embodiment of the present invention, even when a coating layer is formed on the tin surface of plate glass, wrinkle prevention can be suppressed and a coating layer with excellent durability can be obtained.

[0118] The present invention is not limited to the above embodiments but can be manufactured in various different forms, and those skilled in the art will understand that the invention can be implemented in other specific forms without changing the technical concept or essential features of the invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0119] 1000, 1001, 1002: Transparent substrate equipped with a thin film multilayer coating 100: Plate glass 101: Commentary 102: Air surface 200: Anti-wrinkle layer 10: Antioxidant layer 20: Lower metal protective layer 30: Metal functional layer 40: Upper metal protective layer 50: Anti-reflective layer 60: Overcoat layer 210, 211: First thin film multilayer coating 220: Second thin film multilayer coating 2000: Multi-glazing unit

Claims

Claim 1 A transparent substrate comprising a plate glass including a tin surface, a first thin film multilayer coating formed on the tin surface, and a wrinkle-prevention layer formed between the tin surface and the first thin film multilayer coating and in direct contact with the tin surface, wherein the first thin film multilayer coating comprises an anti-oxidation layer located closest to the plate glass, at least one metal functional layer formed on the anti-oxidation layer and having an infrared reflection function, and an overcoat layer formed on the metal functional layer, wherein the wrinkle-prevention layer comprises a metal oxide including tin as a first metal and a second metal having a higher ionization tendency than tin, wherein the plate glass includes an air surface located opposite to the tin surface and further comprises a second thin film multilayer coating formed on the air surface, and wherein a thin film multilayer coating is provided on the air surface in which the wrinkle-prevention layer is not formed. Claim 2 In claim 1, the second metal is a transparent substrate having a thin film multilayer coating that is at least one selected from zinc, magnesium, and aluminum. Claim 3 In paragraph 2, the transparent substrate having a thin film multilayer coating in which the metal oxide is tin-zinc oxide (SnZnO). Claim 4 A transparent substrate having a thin film multilayer coating, wherein the thickness of the anti-wrinkle layer is 15 nm to 40 nm, in accordance with claim 1. Claim 5 A transparent substrate having a thin film multilayer coating, wherein the molar ratio of the second metal to the first metal in claim 1 is 0.7 to 1.

3. Claim 6 In claim 1, the oxidation prevention layer is a transparent substrate having a thin film multilayer coating in direct contact with the wrinkle prevention layer. Claim 7 In claim 1, the antioxidant layer is a transparent substrate having a thin film multilayer coating comprising Si3N4. Claim 8 A transparent substrate having a thin film multilayer coating, further comprising, in claim 1, a lower metal protective layer formed below the metal functional layer and an upper metal protective layer disposed above the metal functional layer. Claim 9 In claim 8, the lower metal protective layer and the upper metal protective layer each are a transparent substrate having a thin film multilayer coating comprising NiCr. Claim 10 A transparent substrate having a thin film multilayer coating, wherein, in claim 1, the thin film multilayer coating further comprises an anti-reflective layer comprising Si3N4 disposed between the metal functional layer and the overcoat layer. Claim 11 A transparent substrate having a thin film multilayer coating, wherein the at least one metal functional layer comprises a first metal functional layer and a second metal functional layer, and further comprises a first anti-reflective layer disposed between the first metal functional layer and the second metal functional layer and a second anti-reflective layer disposed on the second metal functional layer. Claim 12 In claim 11, the first anti-reflection layer and the second anti-reflection layer are a transparent substrate having a thin film multilayer coating comprising Si3N4. Claim 13 In claim 1, the transparent substrate having a thin film multilayer coating comprising one or more selected from zirconium-doped titanium oxide, zirconium oxide, zirconium-doped titanium oxynitride, or zirconium oxynitride, wherein the overcoat layer comprises a thin film multilayer coating. Claim 14 delete Claim 15 delete Claim 16 In claim 1, the transparent substrate is a transparent substrate that has been heat-treated in a state where the anti-wrinkle layer and the first thin film multilayer coating are formed on the tin surface of the plate glass. Claim 17 A multi-glazing unit comprising two or more transparent substrates spaced apart from each other with a spacer in between, wherein at least one of the two or more transparent substrates is a transparent substrate having a thin film multilayer coating according to claim 1. Claim 18 A multi-glazing unit according to claim 17, wherein one of the two or more transparent substrates is a transparent substrate having a thin film multilayer coating according to claim 1, and the other of the two or more transparent substrates is a plate glass not having a thin film multilayer coating. Claim 19 In claim 18, a multi-glazing unit having a transparent substrate equipped with a thin film multilayer coating according to claim 1 placed on the indoor side.

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