KR101714390B1 - Temperable low-emissivity glass with improved durability and method for preparing the same - Google Patents

Abstract

More particularly, the present invention relates to a low-emission glass having a high visible light transmittance and a low emissivity while exhibiting excellent durability before and after a heat treatment, and a method of manufacturing the same. will be.

Description

TECHNICAL FIELD [0001] The present invention relates to a low-emission glass which can be heat-treated with improved durability and a method of manufacturing the same.

More particularly, the present invention relates to a low-emission glass having a high visible light transmittance and a low emissivity while exhibiting excellent durability before and after a heat treatment, and a method of manufacturing the same. will be.

Low-emission glass, such as silver (Ag), etc., is deposited on transparent glass in the infrared region to keep the transparency of the glass, while preventing the indoor heating heat from flowing out to the outside in the winter, Refers to functional building materials that reflect radiant heat. Low emissivity glass was used only for non - residential buildings with large glass construction area in the beginning. However, recently, as the need for energy saving increases, the number of applications for residential buildings is increasing, and the demand for low emission glass with the characteristic is increasing.

Low-emission glass used in non-residential buildings preferentially requires superior insulation / shielding performance and beautiful appearance instead of high transmittance, whereas low-emission glass used in residential buildings requires high transmittance for visibility. Also, because of the high usage rate compared to the low-radiation glass used in non-residential buildings, high durability should be ensured that can be used by many processing agencies.

The structure of the low emission glass manufactured by the sputtering method includes an infrared reflective metal layer and has a dielectric layer at the upper and lower portions of the metal layer to protect the metal layer. However, since a metal is used as a target raw material in an oxygen or nitrogen atmosphere when depositing a dielectric layer on an infrared reflecting metal layer, the infrared reflecting metal layer is oxidized or nitrified by oxygen or nitrogen injected into the chamber to form an interlayer boundary between the infrared reflecting metal layer and the dielectric layer There is a problem that the emissivity value is increased and the characteristics of the low-emission glass is lost.

The membrane structure proposed in EP-A-0718250 introduces an oxygen barrier diffusion layer, in particular a layer based on silicon nitride (SixNy), on top of the silver-based functional layer or layers and a priming layer Alternatively, a silver layer is placed directly over the underlying dielectric coating without inserting a protective metal layer. However, such a film structure is difficult to handle because the functional layer is easily damaged due to external friction and moisture, and after the heat treatment, the Ag coating film deteriorates or fogging phenomenon becomes severe, and the Ag film loses the function of reflecting the infrared region, It is not suitable for use as

WO 97/48649 describes a multi-layer structure with two thin metal "barrier" layers based on niobium and having a thickness of 0.7 to 2 nm. However, it is very difficult for such a structure to satisfy the transmittance of 70% or more after heat treatment.

U.S. Patent No. 6,804,048 discloses a heat-treatable low emissivity glass having a glass / SnO ₂ / ZnO / Ag / Nb / Si ₃ N ₄ multilayer structure. However, this low-emission glass has a disadvantage in that the coating film is easily damaged due to its low chemical durability and fogging occurs in the coating film during the heat treatment or bending process.

Korean Patent No. 1015072 and Korean Patent Laid-Open Publication No. 1998-69748 disclose a film structure having a fog preventing layer and a metal protective layer including Zn-based oxides on the upper and lower portions of an Ag layer to reduce fogging during heat treatment. However, this film structure is disadvantageous in that the functional layer damage may occur when the long-term coating film is exposed to the outside due to the weak durability of the Zn-based oxide.

An object of the present invention is to provide a low-emission glass having a high visible light transmittance and a low emissivity while exhibiting excellent durability before and after heat treatment, and a method for producing the same.

The low emission glass of the present invention comprises a glass substrate, a first dielectric layer coated on the glass substrate, a first metal barrier layer coated on the first dielectric layer, an infrared reflective metal layer coated on the first metal barrier layer, A second metal barrier layer coated on the infrared reflective metal layer, a second dielectric layer coated on the second metal barrier layer, and an overcoat layer coated on the second dielectric layer.

A method of manufacturing a low emissivity glass of the present invention comprises the steps of: coating a first dielectric layer on a glass substrate; coating a first metal barrier layer on the first dielectric layer; coating an infrared reflective metal layer on the first metal barrier layer Coating a second metal barrier layer on the infrared reflective metal layer, coating a second dielectric layer on the second metal barrier layer, and coating the overcoat layer on the second dielectric layer.

According to the present invention, it is possible to produce a low-emission glass having a visible light transmittance of 70% or more and an emissivity of 0.2 or less, while exhibiting excellent durability before and after heat treatment.

Hereinafter, the present invention will be described in detail.

In the present invention, as the glass substrate, for example, ordinary glass such as soda lime glass used for construction or automobile may be used. Depending on the intended use, glass having a thickness of 2 to 12 mm can be freely used. For example, transparent soda lime glass having a thickness of 5 mm or 6 mm can be used.

In the present invention, the first and second dielectric layers function to protect the infrared reflecting metal layer from ions or oxygen during heat treatment and to control optical properties. To prevent the transmittance decrease, the first and second dielectric layers have a refractive index of 1.8 or more and an absorption coefficient of 0.1 or less . ≪ / RTI >

As the first and second dielectric layers, metal nitrides, metal oxides or metal oxides can be used independently, and for example, oxides of Zn, Ti, Si, Nb, Sn, Al, Zr, Ta, Nitride or nitrate can be used. According to one embodiment of the present invention, Si-containing nitride (e.g., Si ₃ N ₄ ) may be used as the first and second dielectric layers.

The thicknesses of the first and second dielectric layers may be independently 20 to 50 nm. If the thickness of each of the first and second dielectric layers is less than 20 nm, the durability may be poor. If the thickness is more than 50 nm, the transmittance may be decreased.

In the present invention, the first and second metal barrier layers function to improve the adhesion between the infrared reflective metal layer and the dielectric layer, and prevent diffusion of Na and O _{2 in} the air during heat treatment such as strengthening and bending. And serves to help fusion of the infrared reflective metal so that the infrared reflecting metal layer can stably behave even at a high heat treatment temperature and ultimately helps to maintain the low radiation performance by absorbing the O ₂ penetrating into the infrared reflecting metal layer .

The first and second metal barrier layers may be independently selected from Ni, Cr, and Ni-Cr alloys. When a Ni-Cr alloy is used, the alloy composition may be Ni To 85 wt%, and Cr of 15 to 25 wt%. According to one embodiment of the present invention, a Ni-Cr alloy may be used for the first and second metal barrier layers.

The thickness of the first and second metal barrier layers may be independently from 2 to 6 nm. If the thickness of each of the first and second metal barrier layers is less than 2 nm, the durability may be deteriorated and the fogging of the coating film may increase after the heat treatment and the bending process. If the thickness exceeds 6 nm, the transmittance may be lowered, There may be a problem that the fog of the coating film also increases after the process.

In the present invention, the infrared reflective metal layer selectively reflects sun rays to provide a high shielding performance and low emission.

As the infrared reflective metal layer, a metal having excellent conductivity may be used. For example, at least one metal selected from gold, silver, platinum, aluminum and copper may be used. According to one embodiment of the present invention, silver (Ag) may be used as the infrared reflecting metal layer.

The thickness of the infrared reflecting metal layer may be 5 to 10 nm. If the thickness of the infrared-reflective metal layer is less than 5 nm, the reflective metal layer may not be normally formed, resulting in insufficient low-emission performance. If the thickness exceeds 10 nm, the transmittance may decrease and the reflectance may increase.

In the present invention, the overcoat layer protects the dielectric layer and the infrared reflective metal layer.

As the overcoat layer, a material having a high mechanical strength, a small surface roughness and a high transmittance may be used. For example, oxides, nitrides or nitrides of Si, Nb, Ti, Zr, Ta or an alloy thereof may be used. According to one embodiment of the present invention, a Ti-containing oxide or a nitrate (e.g., TiO _x N _y ) may be used as the overcoat layer, wherein x: y is 100 Mol%: 0 mol% to 75 mol%: 25 mol%.

The thickness of the overcoat layer may be between 2 and 15 nm. If the thickness of the overcoat layer is less than 2 nm, the durability may be deteriorated. If the thickness of the overcoat layer is more than 15 nm, the transmittance may be decreased or fog may be caused.

The low-emission glass of the present invention can exhibit a visible light transmittance of 70% or more or 75% or more when measured after heat treatment with a D65 standard light source of 380 to 780 nm on the basis of a transparent glass substrate thickness of 6 mm, Or an emissivity of 0.1 or less.

The low-emission glass of the present invention can be produced by using a vacuum sputtering method as a thin film forming method for forming a laminate of each coating film. That is, in the low-emission glass manufacturing method of the present invention, the formation of each layer can be performed by a sputtering deposition method.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the scope of the present invention is not limited to these examples.

[ Example  And Comparative Example ]

Low-emission glass in which a multilayer coating film having the composition and thickness shown in Table 1 below was formed as an example on a 6 mm transparent glass substrate using a magnetron sputter coater and a low-emission glass having a composition and thickness shown in the following Table 2 And low-emission glass in which a multilayer coating film was formed.

Examples In the glass, SiAlNx layer is a nitrogen / argon: was coated under (nitrogen ratio of 45 to 60% by volume) atmosphere, NiCr alloy layer and the Ag metal layer was coated under argon 100% atmosphere, TiO _x N _y (x: y = 3: 1) layer was coated using a TiO _x ceramic target under a nitrogen / argon (nitrogen ratio: 45-60 vol%) atmosphere.

In the comparative glass, the SiAlN _x layer (dielectric layer) was coated in an atmosphere of nitrogen / argon (nitrogen ratio: 45 to 60 vol%), and the ZnAlO layer (crystal nucleation layer) was coated with oxygen / argon Vol.%). The NiCr alloy layer, the Ag metal layer and the TiO _x N _y (x: y = 3: 1) layer were coated in the same manner as in Example.

The thickness of the infrared reflective metal layer was adjusted so that the emissivity was 0.2 or less in both Examples and Comparative Examples.

The glass samples prepared in the examples and comparative examples were subjected to a heat treatment under the condition that upper and lower temperatures were passed through the general reinforcing furnace used for producing the tempered glass at about 720 ° C in an advantageous state and heated for about 10 minutes and then slowly cooled. Optical properties and durability were measured using the following equipment.

- Visible light transmittance, solar radiation transmittance: Measured according to KS L 2514 and ISO 9050 using a Lambda 950 spectrophotometer from Perkinelmer.

- Surface resistance: Measures the surface resistance of the low radiation coated surface using a 4 point probe type surface resistance meter.

- Scratch resistance: After distilled water was sprayed on the coated surface, the nylon brush of 0.5 mm in thickness was reciprocated 200 times horizontally to the low radiated coated surface, and the number of scratches on the coated surface was evaluated.

- Emissivity: Measured according to KS L 2514 standard using FT-IR from Nicolet.

- Moisture resistance: Measure the number of pinholes on the surface of the aftercoat after storage for 7 days at 30 ℃ and 80% relative humidity.

The measurement and evaluation results are shown in Table 3 below.

As can be seen from the results of Table 3, the low-emission glass of Examples had higher scratch resistance and moisture resistance than the glass of the comparative example of the prior art, thereby remarkably improving durability and handling.

Also, as the thickness of Ag increases, the reflection characteristics of infrared rays are improved, but the durability is degraded. In addition, when the thickness of the upper NiCr on the Ag is increased, the moisture resistance and scratch resistance are improved, but a clouding phenomenon occurs after the heat treatment.

Claims (11)

A liquid crystal display device comprising: a glass substrate; a first dielectric layer coated on the glass substrate; a first metal barrier layer coated on the first dielectric layer; an infrared reflective metal layer coated on the first metal barrier layer; A second metal barrier layer, a second dielectric layer coated on the second metal barrier layer, and an overcoat layer coated on the second dielectric layer,
The first and second dielectric layers are SiAlNx,
Wherein the overcoat layer is a Ti-containing oxide (TiO _x N _y ), wherein x: y is from 75 mol% to less than 100 mol%, from 0 mol% to 25 mol%, based on 100 mol% ,
Low radiation glass. delete The low emissivity glass according to claim 1, wherein the thicknesses of the first and second dielectric layers are independently 20 to 50 nm. The low radiant glass according to claim 1, wherein the first and second metal barrier layers are each independently selected from Ni, Cr and Ni-Cr alloys. The low emissivity glass according to claim 4, wherein the thickness of the first and second metal barrier layers is independently from 2 to 6 nm. 6. The low radiant glass according to claim 5, wherein the thickness of the overcoat layer is 2 to 15 nm. The low emissivity glass according to claim 1, wherein the thickness of the infrared reflecting metal layer is 5 to 10 nm. delete delete delete delete