JPH0550548A - Thermal ray-reflecting glass with radio wave-low reflecting property - Google Patents

Abstract

PURPOSE:To obtain thermal ray-reflecting glass excellent in heat-insulating property while radio wave-obstruction is remarkably reduced by a method in which the membrane part which has relatively high radio wave-reflectance and lower surface resistivity than a specified value, is divided, and the length of the side parallel to the direction of the electric field of approaching radio wave is kept at most specified times of the wave length of radio wave, and then the penetration ratio of sun light- radiation is limited. CONSTITUTION:The surface resistivity of a membrane, a film or a platelike object 2 is at most 5000OMEGA/?. While the length L of the side parallel to the direction of the electric field of the approaching radio wave of the membrane, the film or the platelike object 2, is divided so that the length L is kept at most 1/20 times the wave length of radio wave, and a dividing groove 3 is formed, the penetration ratio of sun light- radiation is kept at most 50%. In the dividing groove 3, the width of the groove parallel to the direction of the electric field of the approaching radio wave is 0-5mm, and the width of the groove perpendicular thereto is 0.5-5mm, and further said divided shape is made into stripe shape or lattice work. Consequently, the thermal ray- reflecting glass which has sufficient heat insulation and radio wave-low reflecting property may be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat ray reflective glass which prevents radio waves from being obstructed by a building or the like and transmits radio waves efficiently.

[0002]

2. Description of the Related Art In recent years, when receiving television radio waves, ghost damage due to building reflection has become a problem, and it is becoming practical to install a ferrite radio wave absorber on a concrete wall of a building.

On the other hand, as window glass is gradually thicker, more and more glass is coated with a film of metal, metal oxide or the like, or a film having such a film is attached to the glass, which has functions such as heat insulation. Tend to. The effect of the thickness is not so great, but if a film that has a higher reflectivity for radio waves than glass is coated or a film is attached, the reflectivity will be quite high, for example, and there is a possibility that radio interference will be unavoidable. It was Therefore, in such a case, the window in the direction of arrival of radio waves had to be provided with uncoated glass, and it was impossible to avoid the incongruity that the color tone was different in the same building. It was sometimes necessary to reduce the heat insulation effect on the windows of the entire building.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made in view of the above circumstances, and it can be said that the reflectance is reduced for radio waves such as TV broadcast waves so that no radio interference occurs. It is an object of the present invention to provide a heat ray reflective glass having a radio wave low reflection characteristic, which has a radio wave reflectance value as close as possible to a bare sheet glass not covered with and has sufficient heat insulation performance.

[0005]

[Means for Solving the Problems] That is, the present invention is
A heat ray reflective glass comprising a substrate, and a film, a film or a plate having a high heat ray reflectance laminated on the substrate, wherein the film, the film or the plate has a surface resistivity of 500 Ω / port or less, and the film or the film. Alternatively, the length of the side parallel to the electric field direction of the incoming radio wave of the plate-shaped body is 1/2 of the wavelength λ of the radio wave.
A heat ray reflective glass having low radio wave reflection characteristics, characterized in that it is divided into 0 times or less to form division grooves and has a solar radiation transmittance of 50% or less. In addition, the split grooves have the above-described low radio wave reflection characteristics, characterized in that the width of the parallel groove is 0 to 5 mm and the width of the orthogonal groove is 0.05 to 5 mm in the electric field direction of the incoming radio wave. Heat ray reflective glass. Further, the present invention provides the heat ray reflective glass having the above-described radio wave low reflection characteristic, wherein the divided shape is a stripe shape or a lattice shape.

Here, the reason why the surface resistivity of the film, film or plate having the high heat ray reflectance is 500 Ω / port or less is that the surface resistivity is 1 kΩ / port or more. Although the reflectance is low, the heat insulation performance is deteriorated. Therefore, if the surface resistivity is 1 kΩ / mouth or less, the reflectance of radio waves is gradually increased and the heat insulation performance is increased. On the other hand, both the radio wave reflectance and the solar radiation transmittance have good values of 500Ω.
/ It was below the mouth. It is preferably 400 Ω / mouth or less, more preferably 350 Ω / mouth or less. For example, in the case of highly insulating glass including not only the blocking of sunlight but also the heat insulation by reflection of infrared rays, the reflection of infrared rays is due to plasma vibration. Therefore, since the reflectance is controlled by the surface resistance of the film, the surface resistance of the sputtered film needs to be 500 Ω / hole or less.

Particularly, in LOW-E glass having a surface resistivity of several Ω / neck, a reflection problem becomes a serious problem, and in LOW-E glass mainly used in cold regions, daytime sunlight is positively incorporated. Therefore, the solar radiation transmittance is smaller than that of ordinary heat insulating glass (for example, product name: Skycool), but the infrared reflectance is extremely high. The film, film or plate having a high heat ray reflectance may be a single layer or a multilayer, and the thickness thereof is about 1000 Å or less, preferably about 800.
It is about Å or less, more preferably about 500 Å or less.

Further, the reason why the solar radiation transmittance is set to 50% or less is that the heat insulating effect is not always sufficient when it exceeds 50%, preferably about 40% or less, and more preferably about 40% or less. It is about 5 to 30%, which is almost the same as that of ordinary insulating glass (for example, product name: Sky Cool).

Next, the division groove is formed by dividing the length of the side parallel to the electric field direction of the incoming radio wave of the film, film or plate so as to be 1/20 times or less the wavelength λ of the radio wave. This is done by, for example, as already proposed by the applicant, 1/3 times or less of the wavelength λ of the radio wave, preferably 1
The length of the side is not more than / 4 times, but it is necessary to achieve the intended purpose described above even under more severe environment or conditions, and preferably not more than 1/30 times. For example, the thickness of the sputtered film is about 300Å
With a thin film of a certain degree, the absorption of radio waves can be ignored, and the decrease in the shielding effect is a phenomenon that occurs as a result of a decrease in radio wave reflectance.

Further, the division groove (slit)
The width of the groove parallel to the electric field direction of the incoming radio wave is 0-5 m
m, the width of the orthogonal groove is 0.05 to 5 mm, the larger the width of the dividing groove is, the less the radio interference is. In the case of using the heat insulating film, the surface resistivity is about 50Ω / mouth, the solar radiation transmittance is about 6 to 7%, and the radio wave reflectance is about 56% (at a frequency of 200 MHz). The deterioration of heat insulation performance due to the division of, for example, from about 7% to 19% within about 3 times, if possible about 14
%, It is desirable to stop within about 2 times, and in addition, if the width of the groove becomes 5 mm or more, the designability and the like tend to be easily lost. 5 mm or less, preferably about 3 mm
It is about the following or less, and more preferably 1 of the wavelength λ of the incoming radio wave.
/ 1500 mm times or less (corresponding to about 1 mm or less at 200 MHz).

That is, preferably, the width of the groove parallel to the electric field direction of the incoming radio wave is 0 to 3 mm, and the width of the groove orthogonal thereto is 0.
1 to 3 mm, more preferably the width of the parallel grooves is 0 to
The width of the groove is 3 mm and the orthogonal groove is 0.3 to 3 mm. In the case of horizontal polarization, the width of the horizontal groove may be zero,
In the case of vertically polarized waves, the width of the groove in the vertical direction may be zero, and may be stripe or lattice.

Further, with respect to the lower limit of the stripe width, for example, in the case of the above-mentioned ordinary high heat insulating product,
When the solar radiation transmittance is about 5 to 30% and the frequency of the radio wave is 200 MHz, if the width of the groove is 0.5 mm, a heat insulating effect can be expected up to a stripe width of about 3 mm. The range of the division width is about 2/1000 to 1/30 of the wavelength λ. If the width of the groove is made smaller, this lower limit becomes smaller. On the other hand, if the width of the groove is too small, the TV broadcasting band has a high frequency, so the current jumps over the gap of the groove due to the displacement current defined by Maxwell, and the insulating film electrically becomes a continuous body. There is a phenomenon of being lost. However, the groove width that can be processed by laser is about 0.05m
At about m, for example, even when the incoming radio wave has a high frequency of 10 GHz, it functions as the groove and transmits the incoming radio wave.

[0013]

The inventors of the present invention have made earnest studies to reduce the radio wave interference caused by a plate having a high reflectance for radio waves such as a heat insulating glass, and as a result, as a result, a specific high heat ray reflective film or film for coating a substrate. Alternatively, the present invention is made paying attention to the unique division of the plate-shaped body. As described above, by dividing the length (L) of the side parallel to the electric field direction of the incoming radio wave to 1/20 times or less of the wavelength λ of the radio wave, a low radio wave reflectance glass having a value closer to that of the base plate glass is obtained. It is found that the amount of reflection is significantly reduced, and there is a similar tendency from the TV broadcast wave VHF band of 90 MHz to the entire TV broadcast wave UHF band of 770 MHz.

This is considered to be due to the following reasons. That is, when a plane wave is incident on an arbitrary scatterer, a conductive current or a polarization current flows through the scatterer, which serves as a secondary radiation source to generate an electromagnetic wave and reflect the electromagnetic wave. Actually, the electrons do not move from end to end of the scatterer, but only tuned to the frequency of the incident electromagnetic wave and the electrons oscillate at a certain point. A site having a high electron concentration generated by such electron vibration moves. This is a factor that reflects electromagnetic waves, and by dividing the plate-like body or the like to reduce L / λ, the region where electrons can move freely becomes narrower, and as a result, the amount of reflection per unit area decreases. It is estimated that

When a radio wave having a frequency of f is vertically radiated to a conductive film or film having a thickness of x (m), the radio wave transmittance E becomes E = exp (-αx). Here, α is the attenuation constant of the conductive film, and α = 4.82 · π ·
Since it is expressed as f ^1/2 , for example, x is 500Å and f is 10
When the frequency is 0 MHz, the transmittance E is 0.93, which is hardly absorbed, and the amount of reflection is reduced by dividing, so that it is understood that the radio waves are efficiently transmitted. By these, the radio wave reflectance of the incoming radio wave becomes closer to that of the base glass.

On the other hand, as for the heat insulating performance, a unique thin film having a relatively high radio wave reflectance and a specific surface resistivity is used so as to exhibit a heat insulating effect as close as possible to the existing high-performance heat insulating glass. In addition, it will be possible to achieve the same quality as the current high-performance insulating glass. In other words, with the current high-performance insulating glass, it is possible to solve problems that are difficult to solve radio interference, eliminate the ghost phenomenon in TV images, reduce the load on cooling and heating, and use the thin film of the current high-performance insulating glass as it is. The present invention provides a heat ray reflective glass which has the same color tone, is environmentally friendly, and has excellent habitability and low radio wave reflection characteristics.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 and 2 are perspective views showing a part of a heat ray reflective glass having a radio wave low reflection characteristic embodying the present invention.

That is, the substrate 1 is about 520 mm square,
An example will be described in which a float glass having a plate thickness of about 10 mm is used, and the plate glass is coated with a film having a heat insulating property by a DC magnetron sputtering method. In addition,
The coating film having the heat insulating property is a nitrogen gas whose target is metallic titanium and is depressurized to about 10 ⁻³ Torr (however, the flow rate ratio of the argon gas to the nitrogen gas is 0/1.
The surface resistivity of the film is about 3 Ω / port,
About 50Ω / mouth, about 100Ω / mouth, about 350Ω / mouth, about 5
Six types of heat ray-reflecting glass having 00 Ω / mouth and about 1000 Ω / mouth were produced.

Next, the above-mentioned sputtered film is cut by a YAG laser with a slit width which is a dividing groove (D) of about 0.5 mm, and as shown in FIG. 1, the stripe width (L +
D) is about 25 mm, about 50 mm, about 100 mm, about 15
Each heat ray reflective glass plate composed of a 0 mm striped patch was produced. The heat ray reflecting glass plate is fixed in a state in which a window of about 500 mm square is hollowed out in a wall shared by adjacent shield rooms, and about 25 mm (for example, 20 to 30 mm) around the heat ray reflecting glass plate is insulated and made vertical. I installed it. In the attached state, each of the above-mentioned heat ray reflective glass plates was irradiated with horizontal polarized waves having a frequency of 200 MHz and the shield effect was measured, and the effects as shown in Table 1 were obtained.

[Table 1]

As is clear from Table 1, the shielding effect of the glass obtained by dividing the heat ray reflective film having a surface resistivity of about 50 Ω / port into stripes was obtained by coating the entire surface with the heat ray reflective film having a surface resistivity of about 500 Ω / port. It is almost the same as the one. That is, for example, according to the present embodiment, by dividing the film into stripes, while maintaining the solar radiation transmittance of about 6% with a film having a relatively low surface resistance, the solar radiation transmittance coated on the entire surface is about 50%.
The amount of radio wave reflection can be reduced to a level corresponding to a relatively high surface resistance. Furthermore, as mentioned above,
For example, in heat ray reflective glass for construction, in order to efficiently shield heat rays, at least about 30 to 40% is required as the solar radiation transmittance due to the restriction of thermal properties such as solar radiation transmittance. Is reflected by the plasma oscillation of free electrons in the thin film, so the solar radiation transmittance is also governed by the surface resistance of the thin film. To secure the solar radiation transmittance of about 30%, the surface resistivity of the coating film is It is sufficiently satisfied that it is required to be about 350 Ω / port or less.

The thickness of the sputtered film in this embodiment is about 300Å, the absorption of radio waves is almost negligible in the thin film, and the reduction of the shield effect is caused by the reduction of the radio wave reflectance. It is a phenomenon. Furthermore, the present invention is not limited to the preferred embodiments described above, and various applications are possible.

The film or film laminated on the substrate of the present invention has a surface resistivity of 1 if only low reflection of radio waves is present.
An effect can be expected if it is less than or equal to kΩ / port, but a material having a sufficient heat insulating property has a surface resistivity of 50.
Various known films, films and the like having a resistance of 0 Ω / port or less, preferably about 400 Ω / port or less, and more preferably 350 Ω / port or less can be used. Further, the plate-like body laminated on the substrate may be plate glass, plastic or the like, or a building material such as ceramics or concrete, or a metal having a high reflectance. Furthermore, for example, the high heat ray reflective film is divided into a low radio wave reflection surface, and a high surface resistance (for example, a surface resistivity of 1 kΩ / port or more, preferably 20 kΩ
It is needless to say that a thin film (/ port or more) may be coated as a protective film.

The length of the side parallel to the electric field direction of these incoming radio waves depends on the frequency of the radio waves whose reflectance is to be reduced, and the TV broadcast wave VHF band (90 MHz to 220 MH).
up to z), for example, at a frequency of 90 MHz and a wavelength (3333 mm) / 20, it is about 167 mm, and a wavelength (3333 mm) / 30 is about 111 mm,
At a frequency of 220 MHz and a wavelength (1364 mm) / 20, the distance is about 68 mm, and at a wavelength (1364 mm) / 30, the distance is about 45 mm. Further, the TV broadcast wave UHF band (47
In the case of 0 MHz to 770 MHz), for example, at a frequency of 470 MHz, a wavelength (638 mm) / 20 is about 32 mm, and a wavelength (638 mm) / 30 is about 21 m.
m, the frequency is 770 MHz and the wavelength is (390 mm) /
If it is 20, it may be about 19 mm, and if it is a wavelength (390 mm) / 30, it may be about 13 mm.

The substrate may be colorless or colored, and may be flat glass, bent glass, or various types of glass such as strengthened or strengthened glass, and may have a lower radio wave reflectance than a divided film, film or plate. Any material may be used, and various materials such as organic materials such as plastics and inorganic materials can be adopted.

[0025]

The heat ray reflective glass of the present invention having a low radio wave reflection characteristic has a relatively high radio wave reflectance and a surface resistivity of 5.
Divide a part such as a film having a relatively low surface resistivity of 00 Ω / port or less, and set the length of the side parallel to the electric field direction of the incoming radio wave to 1/20 times the wavelength λ of the radio wave or less, and the solar radiation transmittance to 50 % Or less, the radio wave reflectance is reduced, and the radio wave reflectance is as close as possible to the bare plate glass to minimize radio wave interference, and the heat insulation effect is as close as possible to the current high heat insulation product. In addition, it is possible to have the same color tone. Therefore, in a window or the like of a building such as a building, a heat ray reflective glass of the present invention, which has a low radio wave reflection characteristic having, for example, heat insulation performance, is disposed on the window surface from which radio waves arrive, and the same type of heat ray that is not divided When the reflective glass is provided, the entire building exhibits a higher heat insulating effect and the same color tone can be obtained, which is aesthetically preferable.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a heat ray reflective glass having a radio wave low reflection characteristic with a striped patch film according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a part of a heat ray reflection glass having a radio wave low reflection characteristic with a square patch film according to another embodiment of the present invention.

[Explanation of symbols]

 1 substrate 2 film 3 slit

Claims (3)

[Claims] 1. A heat-reflecting glass comprising a substrate, a film having a high heat-reflecting rate, a film, or a plate-shaped body laminated on the substrate,
The surface resistivity of the film, film or plate is 500Ω.
The length of a side of the film, film or plate which is parallel to the electric field direction of the incoming radio wave is divided by dividing it into 1/20 times or less of the wavelength λ of the radio wave. A heat ray reflective glass having a low radio wave reflection characteristic, which is characterized by forming a groove and having a solar radiation transmittance of 50% or less. 2. The division groove is characterized in that the width of the parallel groove is 0 to 5 mm and the width of the orthogonal groove is 0.05 to 5 mm in the electric field direction of the incoming radio wave. Heat ray reflection glass with low radio wave reflection characteristics. 3. The heat ray reflective glass having low radio wave reflection characteristics according to claim 1, wherein the divided shape is a stripe shape or a lattice shape.