JPH0725647A - Heat rays screening glass having reduced film surface reflection - Google Patents

Abstract

PURPOSE:To reflect and absorb visible light rays, etc., and improve screening properties of heat rays by coating a thin film of Cr (alloy), etc., formed on a glass substrate with a thin film of titanium dioxide, etc., further making a thin film of specified conditions on the applied thin film. CONSTITUTION:A transparent glass substrate 2 is coated with a thin film selected from a Fe-Cr-Ni alloy, a Ni-Cu alloy, Ti metal and Cr metal as a first layer 3 and the thickness of the first layer is 3-10nm. The surface of the first layer 3 is coated with a thin film of titanium dioxide or chromic oxide as a second layer 4 and the thickness of the second layer is 20-60nm. Further the surface of the second layer 4 is coated with a film which has <=1.8 refractive index at 500nm wave length and is transparent in a visible light wavelength as a third layer 5 and the thickness of the third layer is 40-100nm. Consequently, visibility of the interior from the exterior is reduced, privacy of persons in a room can be maintained and see-through from the interior to the exterior is raised.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when used as a window glass of a building or an automobile, reflects visible light or near infrared rays from the outside of the building or the automobile and absorbs the visible light when the inside is seen from the outside. Glass suitable for reducing the load required for cooling by suppressing the inflow of energy while securing the privacy of the person in the room by reducing the property, and in particular, while maintaining such characteristics, the building And glass from the inside of a car with improved transparency to the outside.

[0002]

2. Description of the Related Art Conventionally, as such a glass, a glass having a high reflectance of visible light when it is coated with a thin film and viewed from the outside of a building or an automobile is well known. In this glass, the visibility of the inside is reduced by making the reflection of light incident from the outside larger than the amount of light transmitted from the inside through the glass. At the same time as increasing the reflectance of visible light, the reflectance of near infrared rays, so-called heat rays, is also increased, so that the inflow of energy into the interior is suppressed, and heat ray reflection glass that is effective in reducing the cooling load (for example, manufactured by Nippon Sheet Glass It has become widely used for construction purposes under the product name of Lefshine. In the above glass, a nitride film such as titanium nitride or chromium nitride or a metal film such as stainless steel or chromium is used as a single layer or as a multilayer with an oxide film such as tin oxide or titanium oxide. By adjusting, the desired visible light reflectance and color tone are obtained by the optical interference effect.

[0003]

However, in the above-mentioned conventional glass, when the window surface of a building or an automobile is used with the film surface facing the room, the visible light reflectance from the outside is increased to improve the visibility of the inside. At the same time, since the visible light reflectance from the inside of the room is increased, there is a problem in that it is not possible to secure the necessary transparency when the outside of the building or automobile is viewed. To give a concrete example, it is important to ensure the view to the outside as much as reducing the inflow of energy for the application of the window of the prospective restaurant that uses a large area of glass. For such applications, the conventional glass has a high visible light reflectance of light incident from the inside of the room, and it is difficult to secure a view to the outside. In particular, since the amount of external light decreases from the evening to the night, the reflection of the internal illumination light becomes more dominant, and the transparency from the inside is significantly reduced. Similarly, there was a similar problem with the window glass of a sightseeing bus, which has passengers' desire to enjoy the scenery outside. Even if the inflow of energy can be prevented, if the internal visible light reflectance is high, the transparency to the outside is reduced, which is not preferable. In addition, such a glass had a predetermined reflection color tone or transmission color tone from the viewpoint of design,
In recent years, vividly colored glass has tended to be disliked, and in particular, the phenomenon in which the interior of the window glass of a building is colored and reflected at night, which impairs comfort, has been desired to be improved. Also in automobile window glass, it is desired that the transmitted color tone is neutral (neutral color) in view of the balance with the color tone of the interior material. in this way,
An object of the present invention is to reduce the visibility from the outside to the inside of a building or automobile to ensure the privacy of the person inside the room,
Another object of the present invention is to provide a glass that enhances the heat ray shielding property and reduces the cooling load while maintaining high visibility from the inside to the outside of the room, and yet another purpose is to provide neutral glass without exhibiting a vivid color tone. It is to provide glass having various color tones.

[0004]

According to the present invention, an Fe-Cr-Ni alloy or Ni-Cr alloy is formed on one surface of a transparent glass substrate.
A film made of at least one selected from the group consisting of alloys, Ti metals and Cr metals has a thickness of 3 to 10 nm
Coated as a layer, a film of titanium dioxide or chromic oxide on the first layer is coated as a second layer with a thickness of 20 to 60 nm, and a refractive index at a wavelength of 500 nm is 1. 8 or less and 4 transparent films in the visible light wavelength range
A heat ray-shielding glass with reduced film surface reflection, which is coated as a third layer with a thickness of 0 to 100 nm.

3 formed as a first layer on a glass substrate
A layer made of at least one metal selected from the group consisting of Fe-Cr-Ni alloy, Ni-Cr alloy, and Ti or Cr having a thickness of -10 nm reduces visible light and near-infrared rays transmitted through this glass, and inflows energy. Lower. In addition, these alloy films or metal films have similar transmittances over the entire range of visible light, and the visible light transmitted through these films does not exhibit a selective color tone, and a neutral transmitted color tone is obtained. Similarly, these alloy films or metal films have similar reflectance over the entire range of visible light, and the visible light reflected by these films does not exhibit a selective color tone, and a neutral reflection color tone is obtained. To be It is important for the comfort of human beings in buildings and automobiles that the light transmitted through or reflected by the glass does not have a color tone, and the use of these alloy films or metal films also from this viewpoint. preferable. Further, it is considered that these alloy films or metal films have a large adhesion to the glass substrate and have excellent durability against mechanical abrasion.

A layer of titanium dioxide or chromic oxide having a thickness of 20 to 50 nm formed as a second layer and a layer of 40 to 100 nm formed as a third layer are formed on the above-mentioned alloy film or metal film. The transparent layer having a refractive index of 1.8 or less in the visible region is laminated with the first layer,
The reflectance of visible light and near-infrared rays from the glass surface side where these films are not formed is increased, and the reflectance of visible light from the side where these films are formed is made lower than that of the glass used alone. By adjusting the thickness of each of the first, second, and third layers within the above range, the visible light transmittance is 30%.
The reflectance of visible light and near-infrared rays from the glass surface side where the thin film is not formed is 25% or more, and the reflectance of visible light from the side where the thin film is formed is about 50% to the reflectance of the glass alone. Can be made smaller than 8%. further,
It is possible to control the transmission color tone and the reflection color tone to be a neutral color tone. The neutral color tone is a color tone that is difficult to recognize as a specific color when looking at the glass with eyes, and when the color tone is represented by (L ^* , a ^* , b ^* ) of Hunter chromaticity coordinates, the film surface is When the absolute values of a ^* and b ^* on the side are both 5 or less, it is difficult to recognize as a specific color.

A visible light transmittance of 30% or more is important for ensuring the transparency to the outside. Setting the transmittance of visible light to 50% or less is important for reducing the visibility of the inside from the outside, together with setting the reflectance of visible light from the glass surface side to 25% or more. . The visible light reflectance of the glass on the side covered with the thin film, that is, the glass inside the room when used as a window glass of a building or an automobile is 8
It is extremely important to keep the percentage below% in order to prevent the external visibility from being hindered by the reflection of internal light when the external light amount decreases at night and the internal light amount becomes dominant. Is. In the glass of the present invention,
The visible light reflectance on the film surface side is smaller than the reflectance of the glass that does not cover the film. That is, the three-layer film has a characteristic of being an antireflection film.

500n used as the third layer of the present invention
For a film having a refractive index n of 1.8 or less at a wavelength of m,
It is not particularly limited as long as it has a low visible light absorption and is substantially transparent, but has excellent adhesiveness with the second layer of the base,
It is desirable that it has excellent wear resistance and chemical resistance. Examples of such a film material include oxynitride films of silicon dioxide, aluminum oxide, and titanium silicide.

In the most preferable embodiment of the present invention, the visible light reflectance from the film surface side can be suppressed to an extremely low value of 2% or less. Therefore, the thickness ranges of the first layer, the second layer, and the third layer are 3 to 8 nm and 3 respectively.
It is 0 to 60 nm and 70 to 90 nm. When the visible light reflectance is 2% or less, it is close to the reflection characteristics commercially available as low reflection glass or non-reflection glass, and the reflection from the film surface side is reduced to a negligible level. When such glass is used as a window glass for buildings and automobiles, the visibility from the inside to the outside is secured while the visibility from the outside to the inside is reduced in the daytime, and the light inside is dominant from the evening to the night. In that case, the visibility from the outside to the inside is slightly increased, but the reflection of light from the inside of the room is suppressed, so there is no discomfort that the window becomes a mirror, and there is a perspective to the outside. To some extent.

[0010]

The three-layer laminated film coated on one side of the glass according to the present invention has a function of reducing the visibility of the inside when the inside is seen from the outside when the film-coated side is used as the inside. It also has a cooling load reducing function for shielding heat rays and an antireflection function for reflecting the internal light on the film surface.

[0011]

EXAMPLES The present invention will be described in detail below based on examples. FIG. 1 is a partial cross-sectional view of a heat ray-shielding glass 1 of the present invention with reduced visibility, in which a first layer 3, a second layer 4 and a third layer 5 are laminated on a glass substrate 2. Example 1 A stainless alloy (Fe-N) was used for the first cathode of an in-line type sputtering apparatus having three sputtering cathodes.
An i-Cr alloy, SUS316) was used as a target, Ti was used as a target for the second cathode, and quartz glass was used as a target for the third cathode. The washed 5 mm-thick float plate glass was set as a substrate on the substrate carrier in the sputtering apparatus, and then it was evacuated to a pressure of 5 × 10 ⁻⁴ Pa by a vacuum pump. Next, argon (Ar) gas is introduced into the sputtering chamber in which SUS316 is set as a target,
The pressure was adjusted to 0.3 Pa. Electric power was applied to the first cathode from a DC power source to start sputter discharge, and the current was adjusted to 2 A. A carrier on which the substrate was set was passed over the SUS316 target at a predetermined speed to form a stainless alloy film having a thickness of about 5 nm on the glass substrate. Subsequently, oxygen gas was introduced into the sputtering chamber in which Ti was set as a target, and a titanium dioxide film having a thickness of about 37 nm was formed on the stainless alloy film by the same procedure. Next, a mixed gas of 90% Ar gas and 10% oxygen gas was introduced into a sputtering chamber in which quartz glass was set as a target, and the pressure was 0.3 Pa.
Adjusted to. Electric power was applied to the third cathode from a high frequency power source to start sputter discharge, and the electric power was adjusted to 3 kw. Then, in the same procedure, on the titanium dioxide film,
A film of silicon dioxide with a thickness of about 85 nm is formed, and finally a stainless alloy (5 nm) and titanium oxide (37 n
m) and a glass having a three-layer coating made of silicon oxide (85 nm) were obtained. When the optical characteristics of this sample 1 were measured, the visible light transmittance was 47.0% and the solar radiation transmittance was 41.9%, which was an excellent heat ray-shielding property, and the glass surface side (the side on which no film was formed) ) Has a visible light reflectance of 26.5.
%, The visible light reflectance on the film surface side (on which the film was formed) was a low value of only 1.3%. The transmitted color, the reflection color on the film surface, and the reflection color on the glass surface are all in neutral gray system (L ^* a ^* b ^* color system, both a ^* value and b ^* value are within the range of -2 to +2) I wasn't wearing it. The characteristics of the obtained sample are summarized in Table 1.

[0012]

[Table 1]

Example 2 Using the same sputtering apparatus as in Example 1, Cr was set as a target on the second cathode. The procedure of Example 1 was repeated except that chromic oxide was formed instead of titanium dioxide.
m), chromic oxide (41 nm), and silicon dioxide (50 nm). When the optical characteristics of the glass sample 2 thus obtained were measured, the visible light transmittance was 44.1% and the solar radiation transmittance was 42.
It shows an excellent heat ray shielding property of 2%, and the visible light reflectance on the glass surface side (the side on which the film is not formed) is 28.2%, whereas the film surface side (the side on which the film is formed). The visible light reflectance of was as low as 6.2%. The transmitted color was a little bronze (b ^* value was about 6) and the glass surface reflection color was a little green (a ^* value was about -3), but it was not a vivid tone and the reflection color on the film surface was It was a neutral gray series. The characteristics of the obtained sample are shown in Table 1. Examples 3 to 13 In the same procedure as in Examples 1 and 2, the film configurations and the optical characteristics are summarized in Table 1 for Examples in which a stainless alloy, a Ni-Cr alloy, Ti, and Cr are used as the metal layer. Showed. As the glass substrate, 5 mm thick float glass was used. The refractive index n of the aluminum oxide used in Example 11 was about 1.63 in the visible light region, and that of the oxynitride of titanium silicide used in Example 12 was about 1.7.
That of the titanium silicide oxynitride used in Example 13 is about 1.8. The oxynitride refractive index of titanium silicide can be controlled by the amount of oxygen contained. All samples have a visible light transmittance of 30% to 50%.
%, The solar radiation transmittance is smaller than the visible light transmittance and has excellent heat ray shielding properties, and the visible light reflectance from the glass surface (the side on which the thin film is not formed) is 25% or more. However, the visible light reflectance from the film surface (the side on which the thin film was formed) was suppressed to 8% or less, and especially in Sample 7,
9 and 10 have an excellent low reflection property of 2% or less. All the samples were neutral in both transmission color tone and reflection color tone. Sample 12 had a bronze-based transmission color to the same extent as Sample 2, but had a natural feel. The glass surface reflection color was all a silver gray neutral color, and the film surface reflection color was slightly bluish in Sample 9, but it was a level that was hardly noticeable because the film surface reflectance was small. The characteristics of the obtained sample are summarized in Table 1. Comparative Examples 1 to 12 Comparative Samples 1 to 12 in the same manner as in Example 1 except that the film materials of the first layer, the second layer and the third layer and the thickness thereof were changed.
It was created. Since the first layer of metal partially absorbs light in the visible region, if the film thickness is thin, the visible light transmittance is high and the visible light reflectance is low, which impairs the privacy protection function. (Comparative Examples 1 to 3). On the contrary, when the film thickness of the metal layer is increased, the visible light transmittance is decreased, and the transparency from the inside to the outside is decreased (Comparative Sample 1).
3). The results are summarized in Table 2.

[0014]

[Table 2]

Comparative Examples 4 to 7 show the results that, in the film structure shown in Example 1, the optical characteristics deteriorated when the film thicknesses of the second layer and the third layer deviate from the predetermined ranges. When the film thickness of the second layer is less than 20 nm, the reflectance of the glass surface decreases, the glass surface reflection color becomes yellow green, and the film surface reflection color becomes purple. Conversely, the thickness of the second layer is 60 nm
Even if it is thicker, the reflection color of the film surface becomes purple. When the thickness of the third layer is less than 40 nm, the reflectance on the film surface increases and the purple reflected color becomes noticeable. On the contrary, when the film thickness of the third layer is more than 100 nm, the reflectance of the glass surface is lowered, and the purple reflection color becomes remarkable on both the glass surface and the film surface. Comparative Example 8 is an example in which all three layers are close to or slightly off the limits of a predetermined range, but the visible light transmittance is decreased, the film surface reflectance is increased, and the glass surface reflection color is colored (green). ) Has been shown to occur. Comparative Example 9 is an example in which copper (Cu) was used as the metal layer, but the film surface reflectance, visible light transmittance, glass surface reflectance, and color tone were extremely insufficient values.
Comparative Examples 10 and 11 are cases where titanium oxide was used as the second layer and tin oxide was used instead of chromium oxide, but the film surface reflectance was set to a small value and the visible light transmittance and the glass surface reflectance were set to privacy. It cannot be adjusted within the range suitable for protection, and the reflected color becomes noticeable. Comparative Example 12 is
This is an example in which tin oxide having a refractive index n larger than 1.8 is used for the third layer, and the film surface reflectance is 8% which is the glass reflectance.
It cannot be suppressed below.

[0016]

According to the present invention, the visible light reflectance from the film surface side can be reduced while maintaining the privacy protection function and the excellent heat ray shielding function, so that the transparency from the indoor side to the outside can be reduced. Can be improved. In particular, since it is possible to avoid the discomfort that the room is reflected on the window glass from the evening to the night, it is suitable for the application such as the window glass of the view restaurant. Further, since the glass of the present invention has a neutral color tone, it can be used without impairing the harmony of colors with the window glass and various interior and exterior materials.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an embodiment of the present invention.

[Explanation of symbols]

1 ... Heat ray shielding glass with reduced film surface reflection of the present invention, 2
... Transparent glass substrate, 3 ... First layer, 4 ... Second layer, 5 ... Third layer.

Claims (4)

[Claims] 1. Fe-C on one surface of a transparent glass substrate.
A film made of at least one selected from the group consisting of r-Ni alloys, Ni-Cr alloys, Ti metals and Cr metals is coated as a first layer with a thickness of 3 to 10 nm, and titanium dioxide is provided on the first layer. Or the film of chromic oxide is 20 to 6
Coated as a second layer with a thickness of 0 nm, 5 on top of the second layer
A heat ray-shielding glass with reduced film surface reflection, which has a refractive index of 1.8 or less at a wavelength of 00 nm and is covered with a transparent film in the visible light wavelength region as a third layer with a thickness of 40 to 100 nm. 2. The visible light reflectance of light incident from the surface opposite to one surface of the transparent glass substrate is 25% or more,
The visible light reflectance of light incident from the film surface side is made smaller than the visible light reflectance of the transparent glass substrate itself, and the visible light transmittance is set to 30 to 50%. A heat-shielding glass having reduced film surface reflection as described in 1. 3. When the reflected color of light incident from the film surface side is represented by Hunter chromaticity coordinates a ^* and b ^* , the absolute values of a ^* and b ^* are both 5 or less. The heat ray-shielding glass with reduced film surface reflection according to any one of claims 1 to 2. 4. The transparent film in the visible light wavelength region is a film made of at least one selected from the group consisting of silicon dioxide, aluminum oxide and oxynitride of titanium silicide. Item 5. A heat ray-shielding glass having reduced film surface reflection according to items 1 to 3.