KR20170083897A - Second surface mirror having multiple coating and producing method thereof - Google Patents

Abstract

The present invention relates to a transparent substrate, a dielectric film layer coated on the transparent substrate, and an aluminum layer coated on the dielectric film layer, the dielectric film layer comprising a high refractive index dielectric film and a low refractive index dielectric film coated alternately on the transparent substrate, Lt; RTI ID = 0.0 > 2-sided < / RTI >

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a double-

The present invention relates to a multilayer coated two-sided mirror and a method of manufacturing the same.

A two-sided mirror is a mirror coated with silver (Ag) on the rear side of the glass for the reflection of light, that is, a common mirror corresponds to such a two-sided mirror. In the manufacture of a two-sided mirror, a technique such as a wet chemical process (precipitation of silver from silver nitrate solution) or a vacuum deposition process of silver is used to deposit silver from a silver nitrate solution for silver coating on a glass substrate.

Although silver has a high reflectance in a visible light region as compared with other metals such as aluminum, it has a problem of low durability such as flame resistance and abrasion resistance. Also, since the cleaning water resulting from the silver deposition process in wet chemical processes of the prior art for such silver deposition contains substances such as medicines, silver, copper and tin, it must be disposed of in an environmentally friendly manner in addition to the solution used . Furthermore, since silver has poor adhesion to the substrate, there is a problem that it is liable to cause damage such as discoloration due to sulfur compounds such as SO _{2 in the} atmosphere and moisture, degradation of mirror quality, and the manufacturing process cost is high.

As a conventional technique for solving these problems, Japanese Unexamined Patent Application Publication No. 2003-4919 discloses a technique of coating an Al ₂ O ₃ thin film layer between a glass substrate and silver, and Japanese Laid-Open Patent Application No. 2002-226927 Discloses a technique of coating a reflective film obtained by mixing Ce and Nd, and JP-A-2000-81505 discloses a technique of coating chromium oxide (CrO ₂ ) between a substrate and silver, Publication No. 2001-74922 discloses a technique of forming a coating layer composed of silicon oxide (SiO ₂ ) between a substrate and silver, and Japanese Patent Publication No. 2831932 discloses a technique in which sodium ions contained in a glass substrate contaminate a silver reflection film (SiO ₂ ) is used in order to prevent the oxidation of titanium oxide (TiO ₂ ), and Korean Patent No. 10-1286832 discloses a technique of coating titanium oxide (TiO ₂ ).

However, these reflective films have a disadvantage in that the reflectance of the visible light region is lower than that of directly coating the silver on the substrate, or the coating layer is further formed between the silver and the substrate, thereby increasing the cost of the manufacturing process. Therefore, there is still a need for a method of manufacturing a two-sided mirror having an excellent reflectance at low cost.

The present invention includes a dielectric film layer coated on a substrate with a multilayer coated two-sided mirror, and an aluminum layer coated on the dielectric film layer, wherein the dielectric film layer includes a high-refractive-index dielectric film and a low- And to provide a two-sided mirror having excellent reflectance and a two-sided mirror manufactured thereby.

The multi-layer coated two-sided mirror of the present invention comprises a transparent substrate, a dielectric film layer coated on the transparent substrate, and an aluminum layer coated on the dielectric film layer, wherein the dielectric film layer is alternately coated on the transparent substrate A refractive index dielectric film and a low refractive index dielectric film.

The method of manufacturing a multilayer coated two-sided mirror of the present invention comprises the steps of forming a dielectric film layer comprising a high refractive index dielectric film and a low refractive index dielectric film alternately coated on a transparent substrate, and coating an aluminum layer on the dielectric film layer .

The present invention relates to a two-sided mirror fabrication technique using aluminum having a lower reflectance than that of silver but having a reflectance similar to or superior to that of silver, wherein the high-refractive index dielectric layer and the low-refractive index dielectric layer are alternately coated, And coating the aluminum layer. The multilayer coated two-sided mirror of the present invention can achieve a reflectance comparable to or better than that of a silver-coated mirror, and can be made more economical and environmentally friendly because of the use of aluminum.

Since the multilayered coated double-sided mirror of the present invention includes aluminum, it can have a lower material cost than conventional silver-coated double-sided mirrors, and has better chemical, mechanical, and external environment durability than silver. Further, unlike the prior art in which a zinc oxide film, a nickel-containing oxide film, or a nickel-chromium oxide film or the like had to be used as a seed layer due to poor adhesion between the silver and the glass substrate, Aluminum is similar in composition to a glass substrate, so that the adhesion to a glass substrate coated with a thin film layer containing silicon excellent in adhesion to glass can be further improved.

1 is a cross-sectional view of a multilayer coated two-sided mirror according to one embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

The multi-layer coated two-sided mirror of the present invention comprises a transparent substrate, a dielectric film layer coated on the transparent substrate, and an aluminum layer coated on the dielectric film layer, wherein the dielectric film layer is alternately coated on the transparent substrate A refractive index dielectric film and a low refractive index dielectric film.

1 is a cross-sectional view of a multilayer coated two-sided mirror according to one embodiment of the present invention. 1, a low refractive index dielectric film 20, 40, 60 and a high refractive index dielectric film 30, 50 are alternately laminated on a transparent substrate 10, and a reflective metal layer 70 such as aluminum is laminated thereon .

The thickness of the aluminum layer coated on the dielectric film layer of the multilayer-coated two-sided mirror of the present invention is preferably 50 to 60 nm, more preferably 53 to 57 nm. When the thickness is out of the above range, the reflectance Rg of the mirror may be lowered.

The low refractive index dielectric layer of the multilayer coated two-sided mirror of the present invention can include, but is not limited to, silicon-containing oxides, aluminum-containing oxides, silicon and aluminum-containing oxides, magnesium-containing fluorides and combinations thereof . For example, the silicon-containing oxide may be silicon oxide (SiO ₂ ), the aluminum-containing oxide may be aluminum oxide (Al ₂ O ₃ ), and the magnesium-containing fluoride may be magnesium fluoride (MgF ₂ ).

The thickness of the low refractive index dielectric layer of the multilayer coated two-sided mirror of the present invention is preferably 75 to 230 nm, and when the thickness is out of the above range, the reflectance Rg of the mirror may be lowered.

The low refractive index dielectric layer of the multilayer coated two-sided mirror of the present invention may have a refractive index ranging from 1.3 to 1.6, but may not be limited thereto.

The transparent silicon-containing oxide can further increase the reflectance of aluminum. For example, when a high-refractive-index oxide film or a nitride film is laminated on the silicon-containing oxide layer and further a low-refractive-index oxide film layer containing a silicon-containing oxide is alternately laminated thereon, Coated two-sided mirrors can be produced.

The high refractive index dielectric film of the multilayered coated two-sided mirror of the present invention may include at least one selected from the group consisting of oxides and nitrides containing titanium, zirconium, hafnium, aluminum, zinc or niobium, and silicon-containing nitrides, But may not be limited. For example, the high refractive index dielectric layer may comprise titanium oxide (TiO ₂ ), silicon nitride (Si ₃ N ₄ ), niobium oxide (Nb ₂ O ₅ ), zirconium oxide (ZrO ₂ ), or ZnAlO.

The thickness of the high-refractive-index dielectric layer of the multilayer-coated two-sided mirror of the present invention is preferably 50 to 75 nm, and when the thickness is out of the range, the reflectance Rg of the mirror may decrease.

The high refractive index dielectric layer of the multi-layer coated two-sided mirror of the present invention may have a refractive index ranging from 1.9 to 2.6, but may not be limited thereto.

The dielectric film layer of the multilayer-coated two-sided mirror of the present invention may include, but is not limited to, a plurality of dielectric films formed by alternately coating one to ten times of a high refractive index dielectric film and a low refractive index dielectric film.

The multi-layer coated two-sided mirror of the present invention may have a reflectance of at least 86%, but may not be limited thereto.

The transparent substrate of the multi-layer coated two-sided mirror of the present invention may be selected from glass, polycarbonate, polymethylmethacrylate, polyethylene terephthalate, polybutylene terephthalate, polyimide, bakelite and combinations thereof, .

The multi-layer coated two-sided mirror of the present invention may further include, but is not limited to, one or more protective layers selected from a metal protective layer and an inorganic protective layer coated on the aluminum layer.

The metal protective layer and the inorganic protective layer may be coated for the purpose of improving durability such as chemical resistance and scratch resistance in the coated surface. For example, a metal protective layer including nickel-chromium or nickel-chromium nitride and / or an inorganic protective layer such as silicon-containing nitride or oxide may be laminated, but the present invention is not limited thereto.

The method of manufacturing a multilayer coated two-sided mirror of the present invention comprises the steps of forming a dielectric film layer comprising a high refractive index dielectric film and a low refractive index dielectric film alternately coated on a transparent substrate, and coating an aluminum layer on the dielectric film layer . For example, the dielectric layer and the aluminum layer may be formed by a physical vapor deposition (PVD) method or a magnetron sputtering method, but the present invention is not limited thereto. Can be used.

For example, the method of making a multilayer coated two-sided mirror of the present invention may include first coating a low refractive index dielectric layer on a transparent substrate, and then coating the high refractive index dielectric layer and the low refractive index dielectric layer alternately to form a dielectric layer. However, the present invention is not limited thereto. For example, the method of making a multilayer coated two-sided mirror of the present invention can include but is not limited to forming a dielectric film layer by alternately coating a high refractive index dielectric film and a low refractive index dielectric film on a transparent substrate .

The step of forming the dielectric film layer of the multilayer coated two-sided mirror manufacturing method of the present invention may include, but not limited to, coating one to ten times alternating high and low refractive index dielectric films.

Hereinafter, the present invention will be described more specifically by way of examples. However, these examples are provided only for the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

[ Example ]

The multilayer coated double-sided mirrors of Comparative Examples 1 to 4 and Examples 1 to 10 were made into compositions as shown in Tables 1 and 2 below and the reflectance was measured. Physical vapor deposition (PVD) or magnetron sputtering was used to coat the dielectric layer.

The thicknesses of the high-refractive-index dielectric layers or low-refractive dielectric layers of the two-sided mirrors according to the comparative examples and embodiments of Tables 1 and 2 are shown in nanometers (nm) The reflectance Rg is expressed in units of%. The reflectance was measured in the visible region (380 to 780 nm) using a Perkin elmer Lambda 950 instrument and calculated on the basis of KS L 2514.

[Table 1]

[Table 2]

Comparative Example  One

The reflectance of 5 mm soda lime glass was measured.

Comparative Example  2

The reflectance of a glass surface deposited with silver at a thickness of 100 nm on 5 mm soda lime glass was measured. The reflectance in the visible region (380 to 780 nm) was measured to be 89.2%.

Comparative Example  3

The reflectance of the glass surface on which aluminum was deposited to a thickness of 55 nm on 5 mm soda lime glass was measured. The reflectance in the visible light region (380 to 780 nm) was measured to be 82.6%, which was 6.6% lower than that of Comparative Example 2.

Comparative Example  4

After depositing silicon oxide (SiO ₂ ) and aluminum (Al) on 5 mm soda lime glass in order, the reflectance was measured. The measured reflectance was found to be more than 83%, which is the desirable reflectance value of a commercially available two-sided mirror.

Example  1 and 3

After depositing titanium oxide (TiO ₂ ) and silicon oxide (SiO ₂ ) in 5 mm soda lime glass in order (Example 1) or twice repeated deposition (Example 3), aluminum (Al) Respectively. The measured reflectance was about the same as or higher than the reflectance value of the two-sided mirror in which silver of the comparative example 2 was deposited.

Example  2 and 4

After depositing silicon oxide (SiO ₂ ) on 5 mm soda lime glass, titanium oxide (TiO ₂ ) and silicon oxide (SiO ₂ ) were sequentially deposited (Example 2) or twice repeated deposition ) And then aluminum (Al) was vapor deposited to measure the reflectance. The measured reflectance was about the same as or higher than the reflectance value of the two-sided mirror in which silver of the comparative example 2 was deposited.

Example  5 and 7

(Si ₃ N ₄ ) and silicon oxide (SiO ₂ ) were sequentially deposited (Example 5) or twice repeatedly (Example 7) in 5 mm soda lime glass and then aluminum (Al) Were measured. The measured reflectance was found to be equal to or higher than 83%, which is the preferred reflectance value of commercially available two-sided mirrors, or equal to or higher than the reflectance value of the two-sided mirror deposited with silver of Comparative Example 2. [

Example  6 and 8

(Si ₃ N ₄ ) and silicon oxide (SiO ₂ ) were sequentially deposited (Example 6) or twice (Example 8) after depositing silicon oxide (SiO ₂ ) on a 5 mm soda lime glass, And aluminum (Al) was deposited thereon to measure the reflectance. The measured reflectance was similar to or higher than the reflectance value of the two-sided mirror in which silver of Comparative Example 2 was deposited.

Example  9

Silicon nitride (Si ₃ N ₄ ) was deposited on 5 mm soda lime glass, and silicon oxide (SiO ₂ ) and titanium oxide (TiO ₂ ) were repeatedly deposited, and the reflectance was measured. The measured reflectance was found to be equal to or higher than 83%, which is the preferred reflectance value of commercially available two-sided mirrors, or equal to or higher than the reflectance value of the two-sided mirror deposited with silver of Comparative Example 2. [

Example  10

Silicon dioxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), and silicon oxide (SiO ₂ ) were sequentially deposited on a 5 mm soda lime glass, Al) was deposited thereon to measure the reflectance. The measured reflectance was similar to or higher than the reflectance value of the two-sided mirror in which silver of Comparative Example 2 was deposited.

As can be seen from the comparative examples and examples shown in Tables 1 and 2, the multilayered coated double-sided mirror of the present invention exhibited a lower reflectance than silver, It has been confirmed that the courtesy reflects a reflectance similar to or better than that of the two-sided mirror.

Claims (8)

Transparent substrate;
A dielectric film layer coated on the transparent substrate; And
An aluminum layer coated on the dielectric film layer
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Wherein the dielectric film layer comprises a high refractive index dielectric film and a low refractive index dielectric film alternately coated on the transparent substrate. The method according to claim 1,
Wherein the low refractive index dielectric film comprises a material selected from the group consisting of silicon containing oxides, aluminum containing oxides, silicon and aluminum containing oxides, magnesium containing fluorides, and combinations thereof. The method according to claim 1,
Wherein the low refractive index dielectric layer has a refractive index in the range of 1.3 to 1.6. The method according to claim 1,
Wherein the high refractive index dielectric layer comprises at least one selected from the group consisting of oxides and nitrides containing titanium, zirconium, hafnium, aluminum, zinc or niobium, and silicon containing nitrides. The method according to claim 1,
Wherein the high refractive index dielectric layer has a refractive index in the range of 1.9 to 2.6. The method according to claim 1,
Wherein the dielectric film layer comprises a plurality of dielectric films formed by coating a high refractive index dielectric film and a low refractive index dielectric film alternately one to ten times. The method according to claim 1,
A multilayer coated two-sided mirror with a reflectance of at least 86%. Forming a dielectric film layer comprising a high refractive index dielectric film and a low refractive index dielectric film alternately coated on a transparent substrate; And
And coating an aluminum layer on the dielectric film layer.

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