JPH06302988A - Electromagnetic wave shielding body - Google Patents

Abstract

PURPOSE:To improve the transparency of an electromagnetic wave shielding body without deteriorating the intrinsic important function of the shielding body by respectively coating counterposed transparent substrates with fluorine- doped tin oxide films having specific surface resistances. CONSTITUTION:The shielding body 30 is constituted by putting together two transparent substrates 10 at least one surfaces of which are with fluorine-doped tin oxide films 12 with an intermediate 14 composed of polyvinyl butyral (PVB), etc., in between so that the shielding body can exert the function of an electromagnetic wave shielding body. In addition since the difference in refractive index between the film 14 and film 12 is relatively small, because the film 14 is deformed and fill up the rugged surface of the films 12 when the film 14 is stuck to the films 12, the haze value becomes smaller and the transparency of the shielding body can be improved. When the films 12 are constituted so that the surface resistance of the films 12 can fall with the range of 8-12OMEGA/square, especially, the function of the shielding body 30 can be further improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shield having a mating structure. This electromagnetic shield is
It has excellent durability and transparency and is useful, for example, as a window glass for construction.

[0002]

2. Description of the Related Art Electromagnetic wave shielding glasses currently on the market include a multi-layer type using a silver (Ag) film and a laminated type using a conductive mesh. Electromagnetic wave shielding glass using a silver film needs to have a double-layered glass structure due to poor durability of the silver film, and since the sash becomes thicker, a normal sash cannot be used, which is expensive. . In addition, the electromagnetic wave shielding glass using the conductive mesh has some difficulties in terms of transparency because of the mesh.

Therefore, in recent years, a transparent conductive film (indium oxide containing tin, tin oxide containing fluorine or aluminum, zinc oxide containing fluorine or aluminum) is formed on a glass substrate, and a protective film (nitride film containing chromium and boron) is formed thereon. )
A transparent conductive glass having a film formed thereon has been developed (Japanese Patent Application Laid-Open No. HEI 2)
-217,339 gazette). Alternatively, an electromagnetic wave shielding body in which a layer having a conductive film of titanium, zirconium, hafnium nitride, boronitride, carbide, or borocarbide is formed on a transparent substrate has been proposed (Japanese Patent Laid-Open No. 4-585).
98 gazette). These can be used as a single plate and have excellent heat ray reflection performance.

[0004]

However, in the former transparent conductive glass, it is necessary to form a transparent conductive film having a thickness of several thousand A or more in order to exhibit the minimum electromagnetic wave shielding performance. However, forming such a transparent conductive film having a thickness of several thousand Å or more has a drawback that the film forming cost becomes high, and there is a problem that a special high-speed film forming equipment is required. Further, the latter electromagnetic wave shield can be made thin, but the disclosed conductive film can only provide an electromagnetic wave shield performance of about 20 dB.

By the way, in recent years, in an online manufacturing facility for float glass, glass having a fluorine-doped tin oxide (SnO ₂ : F) film formed by a thermal decomposition method has been manufactured. The fluorine-doped tin oxide film has excellent durability as compared with a silver film. For example, when a film having a thickness of about 1500 to 2500 A is formed on glass,
A surface resistance value of 20 Ω / □ is obtained, and a haze value is 3 or less, and transparency is good.

In order to develop the shielding performance as the electromagnetic wave shielding glass, the fluorine-doped tin oxide film formed on the glass must have a surface resistance value of 10 Ω / □ or less. To obtain a film having
The fluorine-doped tin oxide film may be formed to have a film thickness of about several thousand.

However, as the film thickness increases, the crystal grains of the fluorine-doped tin oxide film increase, and the film surface becomes rough. For this reason, a film thickness of about several thousand A has a large haze value and becomes cloudy and remarkably impairs the aesthetic appearance, which is unsuitable as a window glass for construction.

An object of the present invention is to effectively utilize the transparent substrate on which the film having the low resistance value is formed, to ensure the original important function of the electromagnetic wave shield, and to improve the transparency. An object is to provide an electromagnetic wave shield having a combined structure that can be manufactured at low cost.

[0009]

The present invention is an electromagnetic wave shield in which an intermediate film is sandwiched between a pair of transparent substrates, and a fluorine-doped tin oxide film is deposited on at least one of the opposing transparent substrates. The electromagnetic wave shield is characterized in that In the present invention, the surface resistance value of the fluorine-doped tin oxide film is preferably in the range of 8 to 12 Ω / □. The thickness of the fluorine-doped tin oxide film formed on the transparent substrate is preferably about 4000 to 5000A.

The present invention may also be an electromagnetic wave shield in which the above-mentioned electromagnetic wave shield and another transparent substrate coated with a metal oxide film are laminated via an intermediate film.

Further, the above-mentioned electromagnetic wave shield and another transparent substrate in which one or more layers of a metal film, a nitride film or an oxide film are adhered on the surface facing the electromagnetic wave shield. May be an electromagnetic wave shield laminated with an intermediate film interposed therebetween.

The transparent substrate according to the present invention is not particularly limited, but a glass substrate such as a transparent float glass plate is preferable.

The intermediate film is also not particularly limited, and for example, polyvinyl butyral (PVB), ethylene vinyl acetate resin film or the like is used, and a fluorine-doped tin oxide film is adhered to integrally bond the transparent substrates. It has a function and a scattering prevention function when the transparent substrate is damaged.

As the metal oxide film, for example, an oxide film of tin, titanium, chromium or the like can be used, and the film thickness thereof is preferably in the range of 300 to 800A, and more preferably in the range of 400 to 600A. desirable. The metal film is, for example, chromium, stainless steel, tantalum, or the like, the nitride is, for example, titanium, a nitride film of chromium, tantalum, or the like, or the oxide is, for example, oxide of titanium, tin, zirconium, tantalum, or the like. A film can be used, and one kind or two or more kinds can be selected from these groups to form one layer or two or more layers. The film thickness is preferably in the range of 200 to 1000 A as a whole in both cases of single layer and plural layers.

[0015]

The fluorine-doped tin oxide film formed on the transparent substrate has excellent durability. However, in order to obtain high shielding performance, it is necessary to increase the film thickness, which increases the haze value and impairs transparency.

As in the present invention, two transparent substrates each having a fluorine-doped tin oxide film coated on at least one surface thereof are combined together with an intermediate film interposed therebetween, thereby exhibiting a function as an electromagnetic wave shield. At the same time, the intermediate film is deformed by the adhesion with the intermediate film to fill the irregularities on the surface of the fluorine-doped tin oxide film, and since the difference in the refractive index between the intermediate film and the fluorine-doped tin oxide film is relatively small, the haze value is small It is possible to improve transparency. Particularly, when the surface resistance value of the fluorine-doped tin oxide film is configured to be in the range of 8 to 12 Ω / □, a more excellent function as an electromagnetic wave shield is exhibited.

Further, the electromagnetic wave shield and the metal oxide film,
Since the transparent substrate to which the metal film, the nitride film or the oxide film is adhered is combined, it is possible to further impart the heat ray reflection performance.

[0018]

EXAMPLES The present invention will be described below based on examples. FIG. 2 is a cross-sectional view of the electromagnetic wave shield of the present invention, in which fluorine-doped tin oxide films 12 and 12 are deposited on the facing surfaces of a pair of transparent glass substrates 10 and 10, respectively, and are laminated via a PVB film 14. Has been done.

(Example 1) A fluorine-doped tin oxide film 12 having a thickness of 5000 A was formed on the surface of a transparent glass substrate 10 (thickness: 3 mm) by a pyrolysis method in a float plate glass production line. The surface resistance value of the formed fluorine-doped tin oxide film 12 was 10 Ω / □. In addition, the transparent glass substrate 1 on which the fluorine-doped tin oxide film 12 is formed
When the haze value of 0 was measured, it was 5.4.

A pair of transparent glass substrates 10 and 10 are bonded to each other with the fluorine-doped tin oxide films 12 and 12 facing each other with a PVB film 14 interposed therebetween, and they are thermocompression bonded in an autoclave to form an electromagnetic wave shield 30. Obtained.

FIG. 3 shows the measurement result of the electromagnetic wave shielding effect of the plane wave of this electromagnetic wave shielding body 30. The measurement is MIL-S
It was performed by the TD-285 method. From this result, the electromagnetic wave shield 30 is 29.0 at a frequency of 100 to 1000 MHz.
It was found to have an electromagnetic wave shielding effect of 35.0 dB.

The haze value of the electromagnetic wave shield 30 was measured and found to be 2.4. The haze value of the transparent glass substrate 10 was significantly smaller than the haze value of 5.4, and it was confirmed that the transparency was improved.

(Embodiment 2) FIG. 4 shows another embodiment of the electromagnetic wave shield according to the present invention. With the equipment used in Example 1, a fluorine-doped tin oxide film 12 having a thickness of 4500 A was formed on the surface of the transparent glass substrate 10. Next, the fluorine-doped tin oxide films 12 and 12, a pair of transparent glass substrates 10 and 10 facing each other, and a titanium oxide film 18 having a thickness of 500A.
And the transparent glass substrate 16 on which the above is formed, respectively, are bonded via a PVB film, and thermocompression bonded to form a laminated glass structure.
The electromagnetic wave shield 40 was obtained.

When the electromagnetic wave shielding effect of this electromagnetic wave shielding body 40 was measured, almost the same results as in Example 1 shown in FIG. 3 were obtained. The haze value of the electromagnetic wave shield 40 is 2.
Was 5. This is significantly smaller than the haze value of 5.4 in the state where the fluorine-doped tin oxide film 12 of the transparent glass substrate 10 is formed, and it was confirmed that the transparency was improved.

Although the titanium oxide film 18 is formed on the outermost surface of the electromagnetic wave shield 40 in this embodiment, it may be formed on the inner surface of the transparent glass substrate 16.

(Embodiment 3) FIG. 5 shows still another embodiment of the electromagnetic wave shield according to the present invention. First, a 300 A thick titanium nitride film 20 was formed on the surface of the transparent glass substrate 16 by a sputtering method. Then, the titanium nitride film 22 of the transparent glass substrate 16 and the electromagnetic wave shield 30 obtained in Example 1 were opposed to each other, and were pasted together with the PVB film 14 interposed therebetween, and heat-pressed to obtain an electromagnetic wave shield 50.

When the electromagnetic wave shielding effect of this electromagnetic wave shielding body 50 was measured, almost the same results as in Example 1 shown in FIG. 3 were obtained. The haze value of the electromagnetic wave shield 50 is 2.
It was 6. This is significantly smaller than the haze value of 5.4 in the state where the fluorine-doped tin oxide film 12 of the transparent glass substrate 10 is formed, and it is confirmed that the transparency is improved as in Example 2. Was done.

In the present embodiment, the nitride film formed on the surface of the transparent glass substrate 16 is composed of only one layer of titanium nitride film, but a plurality of layers may be formed.

[0029]

As described above in detail, according to the present invention, a fluorine-doped tin oxide film having a surface resistance value of 8 to 12 Ω / □ is adhered to the opposing surfaces of a pair of transparent substrates, and an intermediate film is interposed therebetween. Since it is a laminated laminated structure, it exhibits excellent electromagnetic wave shielding performance and transparency. Moreover, in order to realize this performance, since it can be manufactured by a thermal decomposition method using a normal float glass online manufacturing facility, the manufacturing is easy and no special film deposition facility is required, and the manufacturing cost is reduced. it can.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an electromagnetic wave shield according to the present invention.

FIG. 2 is a sectional view showing an embodiment of an electromagnetic wave shield according to the present invention.

FIG. 3 is a graph showing the electromagnetic wave shielding effect of plane waves of the electromagnetic wave shielding body shown in FIG.

FIG. 4 is a sectional view showing another embodiment of the electromagnetic wave shield according to the present invention.

FIG. 5 is a sectional view showing another embodiment of the electromagnetic wave shield according to the present invention.

[Explanation of symbols]

 10 Transparent Glass Substrate 12 Fluorine Doped Tin Oxide Film 14 PVB Film 16 Transparent Glass Substrate 18 Metal Oxide Film 20 PVB Film 22 Titanium Nitride Film 30, 40, 50 Electromagnetic Wave Shield

Claims (4)

[Claims] 1. An electromagnetic wave shield having an intermediate film sandwiched between a pair of transparent substrates, wherein a fluorine-doped tin oxide film is deposited on at least one of the opposing transparent substrates. Electromagnetic wave shield. 2. The electromagnetic wave shield according to claim 1, wherein the fluorine-doped tin oxide film has a surface resistance value in the range of 8 to 12 Ω / □. 3. An electromagnetic wave shield comprising: the electromagnetic wave shield according to claim 1 or 2; and another transparent substrate coated with a metal oxide film, with an intermediate film interposed therebetween. body. 4. The electromagnetic wave shield according to claim 1 or 2, and one or more layers of a metal film, a nitride film or an oxide film deposited on a surface facing the electromagnetic wave shield. Another transparent substrate is laminated via an intermediate film, and an electromagnetic wave shield is provided.