JP4820738B2 - Electromagnetic wave shielding laminate and display device using the same - Google Patents

Description

  The present invention relates to an electromagnetic wave shielding laminate in which a plurality of layers are laminated on a base material, and a display device including the electromagnetic wave shielding laminate.

  Electromagnetic waves are radiated from the light emitting surface of the plasma display panel (PDP). This electromagnetic wave affects nearby electronic equipment and may cause malfunction. For this reason, it is conventionally known that a transparent conductive film coated on a substrate such as glass is installed on the front surface of the light emitting surface for the purpose of shielding electromagnetic waves.

  For example, from the base material side, an oxide layer containing zinc oxide (ZnO) containing one or more metals as a main component and a metal layer containing silver (Ag) as a main component alternately, total (2n + 1, n Has been proposed (Patent Documents 1 and 2), such as a protective plate for PDP covered with a multi-layered conductive film laminated, and a laminate in which titanium oxide and metal layers are alternately laminated (Patent Documents 1 and 2). reference.).

Such an electromagnetic wave shielding film is generally required to have a high visible light transmittance and a low resistance value. In an electromagnetic wave shielding film in which oxide layers and metal layers are alternately laminated, it is generally known that the number of metal layers is increased or the metal layers are thickened in order to reduce the resistance value.
International Publication No. 98/13850 Pamphlet JP 2000-246831 A

  In the prior art related to Patent Document 1, palladium is added to the silver layer in order to improve the moisture resistance of silver. Therefore, there is a problem that the resistance value becomes large. Further, when the number of metal layers is increased in order to reduce the resistance value, there is a problem that the visible light transmittance is lowered.

  Moreover, in the prior art which concerns on patent document 2, the titanium oxide which is a material with a high refractive index is used as an oxide layer. When a material having a high refractive index such as titanium oxide is used, there is an advantage that a decrease in transmittance is small even when the number of stacked layers is increased. However, a laminate in which titanium oxide and silver are alternately laminated has a problem of poor moisture resistance. Although the moisture resistance can be improved by adding palladium to silver, there is a problem that the resistance value is increased by adding palladium.

  The present invention provides a low-cost electromagnetic wave shielding laminate having a low resistance value and a high moisture resistance as well as a high visible light transmittance, and a display device using the same, in view of the above-described problems of the prior art.

The present invention is an electromagnetic wave shielding laminate in which three or more electromagnetic wave shielding films are laminated on a transparent substrate, wherein the electromagnetic wave shielding film has a refractive index of 2.0 or more in order from the substrate side. A first high-refractive index layer made of, a first oxide layer mainly composed of zinc oxide, a conductive layer composed mainly of silver, and a second high-refractive index composed of a substance having a refractive index of 2.0 or more. The first and second high refractive index layers are layers mainly composed of niobium oxide, and a second oxidation layer is provided between the conductive layer and the second high refractive index layer. has an object layer, the geometrical thickness of the first oxide layer, said second rather larger than the geometrical thickness of the oxide layer, the geometrical film of the first oxide layer A thickness is 2 nm or more and 10 nm or less, and an electromagnetic wave shielding laminate is provided.

The present invention is an electromagnetic wave shielding laminate in which three or more electromagnetic wave shielding films are laminated on a transparent substrate, wherein the electromagnetic wave shielding film has a refractive index of 2.0 or more in order from the substrate side. A first high-refractive index layer made of, a first oxide layer mainly composed of zinc oxide, a conductive layer composed mainly of silver, and a second high-refractive index composed of a substance having a refractive index of 2.0 or more. The first high-refractive index layer and the second high-refractive index layer, which have a refractive index layer and are in direct contact between the electromagnetic wave shielding films, are formed as a single layer, and 2 having a high refractive index layer containing niobium oxide as a main component, and having a second oxide layer between the conductive layer and the second high refractive index layer, the first oxidation layer geometrical film thickness of the object layer, the second rather larger than the geometrical thickness of the oxide layer, the geometrical thickness of the first oxide layer, 2 nm or more Providing an electromagnetic wave shielding laminate, wherein 0nm or less.

  Moreover, this invention provides the display apparatus characterized by including the display screen for displaying an image, and the electromagnetic wave shielding laminated body of this invention provided in the visual recognition side of this display screen.

  The electromagnetic wave shielding laminate and the display device of the present invention are a low-cost electromagnetic shielding laminate having a low visible light transmittance, a low resistance value and a high moisture resistance, and a display device using the same.

<Electromagnetic wave shielding laminate>
Hereinafter, an example of an electromagnetic wave shielding laminate according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 shows an electromagnetic wave shielding laminate 1 according to the first embodiment of the present invention. 1 are different from actual ones for convenience of explanation. In this electromagnetic wave shielding laminate 1, an electromagnetic wave shielding film 100,... Is provided on a transparent substrate 2.
In the present embodiment, four electromagnetic wave shielding films 100 are stacked.

(Base material)
The material of the substrate 2 may be any material that is smooth and transparent and can transmit visible light. For example, a plastic, glass, etc. are mentioned.
Examples of the plastic include polyethylene terephthalate, polycarbonate, triacetyl cellulose, polyether sulfone, and polymethyl methacrylate.
The thickness of the base material 2 is appropriately selected according to the application. For example, it may be a film or a plate. Moreover, the base material 2 may be comprised with a single layer, and is good also as a laminated body of a several layer.
The base material 2 may be used by sticking to another glass plate, plastic plate or the like with an adhesive or the like. For example, the thin film-like plastic substrate 2 may be attached to another plastic plate, a glass plate, or the like, or the glass plate substrate 2 may be attached to another glass plate, a plastic plate, or the like.

(Electromagnetic wave shielding film)
The electromagnetic wave shielding films 100,... Provided on the substrate 2 are respectively a first high refractive index layer 31 and a first oxide layer 32 provided on the first high refractive index layer 31. And a conductive layer 33 provided on the first oxide layer 32 and a second high refractive index layer 35 provided on the conductive layer 33. In the present embodiment, a second oxide layer 34 is further provided between the conductive layer 33 and the second high refractive index layer 35, and the first high refractive index layer 31 and the first oxide are respectively provided. The electromagnetic wave shielding film 100,... Is composed of the layer 32, the conductive layer 33, the second oxide layer 34, and the second high refractive index layer 35.

(High refractive index layer)
The first high refractive index layers 31,..., And the second high refractive index layers 35,... Are made of a material having a refractive index of 2.0 or more. The refractive index is preferably 2.0 or more and 2.7 or less. By setting the refractive index of the first high refractive index layer 31,..., Or the second high refractive index layer 35 to be 2.0 or more, the electromagnetic wave shielding film 100,. The visible light transmittance can be kept high even if the number of stacked layers is increased.
In addition, the refractive index (n) in this specification means the refractive index in wavelength 550nm.

As the material of the first high refractive index layer 31,..., Or the second high refractive index layer 35,..., For example, niobium oxide (n: 2.35), titanium oxide (n : 2.45), tantalum oxide (n: 2.1 to 2.2), and the like. Among these, niobium oxide and titanium oxide are preferable, and niobium oxide is more preferable. In the electromagnetic wave shielding laminate of the present invention, the first and second high refractive index layers are layers mainly composed of niobium oxide. The first high refractive index layer 31, ·, ·, · and the second high refractive index layer 35, ·, · by the · a layer mainly composed of niobium oxide reduces the penetration of water, The moisture resistance of the electromagnetic wave shielding film 100 can be improved .

  In addition, the first high refractive index layer 31,..., Or the second high refractive index layer 35 may be crystalline or in an amorphous state. . Among these, an amorphous state is preferable. By making the first high refractive index layer 31,..., Or the second high refractive index layer 35,... Amorphous, the penetration of water through the crystal grain boundary is reduced. The moisture resistance of the electromagnetic wave shielding film 100,... Can be further improved.

  The geometrical film thickness of the first high refractive index layer 31,... Is preferably 20 to 50 nm, and more preferably 30 to 40 nm. Moreover, 20-50 nm is preferable and, as for the geometric film thickness of the 2nd high refractive index layer 35, ..., ..., 30-40nm is more preferable.

In the present embodiment, four electromagnetic wave shielding films 100 are laminated on the transparent base material 2, and therefore, on the second high refractive index layer 35 in the first electromagnetic wave shielding film 100. The first high refractive index layer 31 in the second electromagnetic wave shielding film 100 is directly laminated. In this case, the second high refractive index layer 35 and the first high refractive index layer 31, all SANYO having the same composition with each other, Ru layers der mainly containing respectively niobium oxide. In FIG. 1, the second high refractive index layer 35 and the first high refractive index layer 31 are collectively shown as high refractive index layers 200,. If necessary, the first high refractive index layer 31 and the second high refractive index layer 35 may be formed by two or more operations.

  Each film of the first high refractive index layer 31 in the first layer stack and the second high refractive index layer 35 in the last layer stack from the viewpoint of reducing the visible light reflectance and expanding the wavelength band in which the low reflectance can be obtained. The thickness is preferably thinner than the high refractive index layers 200,... Moreover, the film thickness of each layer is appropriately adjusted in order to adjust the overall optical characteristics including the base material.

  As a method for forming the first high refractive index layer 31,..., Or the second high refractive index layer 35,..., For example, a sputtering method using a metal oxide reducing target. The method of forming by, an ion plating method, a vapor deposition method, a CVD method etc. are mentioned. Among these, the method of forming by sputtering using a niobium oxide reducing target is the conductive layer 33 when the niobium oxide layer is formed on the conductive layer 33,. This is advantageous in that it can be prevented from being oxidized and can be uniformly formed in a large area at a high speed.

The reducing target of niobium oxide used here is a target that is deficient in oxygen with respect to the stoichiometric composition of niobium oxide. Specifically, a material having a composition represented by the formula Nb ₂ O _X (0 <X <5), having conductivity and capable of being discharged and formed by a direct current sputtering method is more preferable. Alternatively, a method of sputtering in an oxygen atmosphere using metallic niobium as a target can be employed.

  When a reducing target is used, it is preferable to use an inert gas containing 5 to 20% by volume of oxidizing gas as the sputtering gas. As the oxidizing gas, oxygen gas can be generally used, but nitrogen monoxide, nitrogen dioxide, carbon monoxide, carbon dioxide, ozone and the like can also be used.

(Oxide layer)
<First oxide layer>
The first oxide layers 32,... Are made of a material whose main component is zinc oxide. The substance mainly composed of zinc oxide has a crystal structure close to that of silver constituting the conductive layers 33,. Therefore, when silver is laminated on an oxide layer made of a material containing zinc oxide as a main component, silver with good crystallinity can be obtained. It is considered that silver having good crystallinity can reduce the occurrence of migration. From the above, by making the first oxide layer 32,..., A material mainly composed of zinc oxide, silver migration is suppressed, and the first oxide layer 32,. And the conductive layer 33,... Can be maintained. By maintaining the adhesion, moisture can be prevented from entering the interface, and the moisture resistance of silver is improved. When the electromagnetic wave shielding film 100 in the present invention includes a second oxide layer (made of a material containing zinc oxide as a main component), the conductive layer 33 made of silver with good crystallinity,. ,. (And made of a material containing zinc oxide as a main component) can be maintained in the same manner at the interface with the second oxide layer 34,..., And the moisture resistance is further improved. Become.

  Here, silver migration means that silver diffuses and aggregates. When silver aggregates, the moisture resistance becomes poor, and at the same time, the aggregated portion becomes white and the appearance becomes poor.

The substance containing zinc oxide as a main component means that zinc oxide is contained at 80 atomic% or more, preferably 90 atomic% or more. Specifically, it may consist essentially of zinc oxide (ZnO), or an oxide containing zinc oxide as a main component and containing aluminum oxide (Al ₂ O ₃ ) (hereinafter referred to as AZO). ) And an oxide containing zinc oxide as a main component and containing gallium oxide (Ga ₂ O ₃ ) (hereinafter referred to as GZO). Among them, AZO and GZO are preferable from the viewpoint of durability of the oxide layer, and AZO is most preferable because it is closer to the crystal structure of silver.

  Aluminum contained in the deposited AZO is preferably 1 to 10 atomic%, and more preferably 2 to 6 atomic%, based on the total amount of aluminum oxide and zinc oxide. In general, a film formed of zinc oxide alone has a large internal stress. When the internal stress is large, the first oxide layer 32,... Is easily cracked, and moisture easily enters through this portion.

  By setting the aluminum oxide content to 1 atomic% or more, the internal stress of the first oxide layer 32,... Can be reduced, and the possibility of cracking can be reduced. By setting the aluminum oxide content to 10 atomic% or less, the crystal structure of zinc oxide can be maintained.

The first oxide layer 32, ·, ·, geometrical film thickness of the-is state, and are more 10nm or less 2 nm, more preferably 3nm or more 6nm or less. Because the geometric thickness of the first oxide layer 32,... Is 10 nm or less, the effects of the adjacent first high refractive index layers 31,. preferable.

In order to obtain silver with good crystallinity in the conductive layers 33,..., The influence of the base is large, so the geometric thickness of the first oxide layer 32,. It is preferable. The electromagnetic wave shielding laminate of the present invention has a second oxide layer, and the geometric thickness of the first oxide layer 32,... Is the second oxide layer 34,. , not greater than the geometric thickness of the -.

  As the formation method of the first oxide layer 32,..., Physical vapor deposition methods such as vacuum deposition method, reactive deposition method, ion beam assisted deposition method, sputtering method, ion plating method, Examples thereof include a chemical vapor deposition method such as a plasma CVD method. Among them, the DC sputtering method is relatively easy to control the film thickness, can provide a practical film strength even when formed on a low-temperature substrate, and can easily increase the area, so-called in-line. Use of a mold facility is preferable from the viewpoint of easy formation of a laminated film.

<Second oxide layer>
The second oxide layers 34,... Are made of a material whose main component is a metal oxide. Preferred examples of the metal oxide include a material mainly composed of zinc oxide, a material mainly composed of titanium oxide, and a material mainly composed of indium oxide. When a substance mainly composed of zinc oxide is used for the second oxide layer 34,..., The interface between the first oxide layer and the conductive layer 33 made of silver,. As in the case, at the interface between the conductive layer 33 made of silver with good crystallinity, and the second oxide layer 34 made of a material mainly composed of zinc oxide, Adhesion can be maintained, and moisture resistance is further improved, which is preferable.

As the second oxide layer 34,..., An oxide containing titanium oxide, AZO, GZO, and indium oxide as a main component and containing tin oxide (SnO ₂ ) is more preferable. Among them, AZO and GZO are preferable from the viewpoint of durability of the oxide layer, and AZO is most preferable because it is closer to the crystal structure of silver.

  Aluminum contained in the deposited AZO is preferably 1 to 10 atomic%, and more preferably 2 to 6 atomic%, based on the total amount of aluminum oxide and zinc oxide. In general, a film formed of zinc oxide alone has a large internal stress. If the internal stress is large, the second oxide layer 34 is easily cracked, and moisture easily enters through this portion.

  By setting the aluminum oxide content to 1 atomic% or more, the internal stress of the second oxide layer 34,... Can be reduced, and the possibility of cracking can be reduced. By setting the aluminum oxide content to 10 atomic% or less, the crystal structure of zinc oxide can be maintained.

  The geometric film thickness of the second oxide layer 34 is preferably 1 nm or more and 6 nm or less, and more preferably 2 nm or more and 4 nm or less.

  As the formation method of the second oxide layer 34,..., Physical vapor deposition methods such as vacuum deposition method, reactive deposition method, ion beam assisted deposition method, sputtering method, ion plating method, Examples thereof include a chemical vapor deposition method such as a plasma CVD method. Among them, the DC sputtering method is relatively easy to control the film thickness, can provide a practical film strength even when formed on a low-temperature substrate, and can easily increase the area, so-called in-line. Use of a mold facility is preferable from the viewpoint of easy formation of a laminated film.

(Conductive layer)
The conductive layers 33,... Are made of a material containing silver as a main component. Here, the substance containing silver as a main component means that the silver content is 99.8 atomic% or more with respect to all metals contained in the substance. Examples of the substance containing silver as a main component include silver alone and alloys in which at least one metal selected from palladium, platinum, gold, iridium, rhodium, copper and bismuth is mixed in silver. When the silver content is 99.8 atomic% or more, the resistance value of the electromagnetic wave shielding laminate 1 can be reduced even if the conductive layers 33,. Furthermore, since the resistance value can be lowered even if the number of laminated layers of the electromagnetic wave shielding films 100,... Is small, the electromagnetic wave shielding laminated body 1 having a low resistance value and a high visible light transmittance can be obtained.

The silver content in the conductive layers 33,... Is preferably 99.8 atomic% or more, and more preferably 99.9 atomic% or more in terms of cost.
The geometrical film thickness of the conductive layers 33,. The geometric film thickness of each conductive layer 33 may be the same or different.
The conductive layers 33,... Can be formed according to various methods such as sputtering and vapor deposition. In particular, it is preferable to form by a direct current sputtering method from the viewpoint that the film forming speed is high and a uniform layer having a uniform thickness and a large thickness can be formed.

  The number of electromagnetic wave shielding films 100 laminated on the substrate 2 is preferably 2 or more in order to have sufficient electromagnetic wave shielding ability. By setting it to 2 or more, sufficient electromagnetic wave shielding performance can be obtained. Furthermore, it is preferable that three or more layers are laminated. Moreover, since the high visible light transparency can be maintained, it is preferable that the number of lamination | stacking of the electromagnetic wave shielding film 100 is 8 or less. From the above viewpoint, the number of stacked layers is most preferably 3 or more and 6 or less.

<Display device>
Hereinafter, a display device according to an embodiment of the present invention will be described in detail.

[Second Embodiment]
A display device according to a second embodiment of the present invention includes a display screen for displaying an image, and an electromagnetic wave shielding laminate provided on the viewing side of the display screen.
Examples of the display device include a plasma display panel (PDP), a liquid crystal display device (LCD), an electroluminescence display (ELD), and a cathode ray tube display device (CRT).

  The viewing side of the display screen for displaying an image is generally composed of a transparent substrate such as a glass substrate or a plastic substrate. The electromagnetic wave shielding laminate is not particularly limited as long as it is an electromagnetic wave shielding laminate of the present invention. For example, the electromagnetic wave shielding laminate 1 of the first embodiment can be used.

  The electromagnetic wave shielding laminate may be directly attached to the surface on the viewing side of the display screen using an adhesive or the like, or may be installed with a gap between the display screen and the display screen.

  Further, a front plate made of glass, plastic or the like may be newly installed on the viewing side of the display screen, and the electromagnetic wave shielding laminate may be directly attached to the viewing side or display side of the front plate. Moreover, you may install an electromagnetic wave shielding laminated body on the visual recognition side or display side of a front board, leaving a clearance gap between front boards.

[Third embodiment]
The display device according to the third embodiment of the present invention includes a display screen for displaying an image, and an electromagnetic wave shielding film provided on the viewing side surface of the display screen.

As such a display device, for example,
(1) A first high-refractive-index layer made of a material having a refractive index of 2.0 or more, in order from the surface on the viewing side of the display screen, the electromagnetic wave shielding film, a first oxidation mainly composed of zinc oxide A material layer, a conductive layer mainly composed of silver, and a second high refractive index layer made of a material having a refractive index of 2.0 or more, wherein the first and second high refractive index layers are made of niobium oxide. It is a layer having a main component, and has a second oxide layer between the conductive layer and the second high refractive index layer, and the geometric thickness of the first oxide layer is: Larger than the geometric thickness of the second oxide layer, the geometric thickness of the first oxide layer is 2 nm or more and 10 nm or less, and a display device in which three or more layers are stacked,
(2) A first high-refractive-index layer made of a material having a refractive index of 2.0 or more, in order from the surface on the viewing side of the display screen, the electromagnetic wave shielding film, a first oxidation mainly composed of zinc oxide A first high refractive index having a physical layer, a conductive layer mainly composed of silver, and a second high refractive index layer made of a material having a refractive index of 2.0 or more, and in direct contact between the electromagnetic wave shielding films And the second high-refractive-index layer is a single layer formed in a lump, and the first and second high-refractive-index layers are layers mainly composed of niobium oxide, and the conductive layer And a second oxide layer between the second high-refractive index layer, and the geometric thickness of the first oxide layer is the geometrical thickness of the second oxide layer. The geometrical thickness of the first oxide layer is greater than 2 nm and less than or equal to 2 nm and less than or equal to 10 nm. ,
(3) a display device in which the silver content in the conductive layer of the electromagnetic wave shielding film is 99.8 atomic% or more;
(4) A display device in which the second oxide layer of the electromagnetic wave shielding film is an oxide layer containing zinc oxide as a main component can be used.
In this case, the viewing side of the display screen is generally composed of a transparent substrate such as a glass substrate or a plastic substrate.

As the electromagnetic wave shielding film, for example, the electromagnetic wave shielding film 100 of the first embodiment,... Can be used. In this case, the first high refractive index layer 31, the first oxide layer 32, the conductive layer 33, the second oxide layer 34, and the second high refractive index layer 35 are provided on the viewing side surface of the display screen. Laminate in this order.
The electromagnetic wave shielding film can be directly formed on the viewing side surface of the display screen by vapor deposition, sputtering, or the like.

  Hereinafter, the present invention will be described in more detail by way of examples.

[Example 1]
As the transparent substrate, a polyethylene terephthalate film (hereinafter referred to as PET, thickness 100 μm), which is a film with high transmittance for optical applications, was used.
For the sputtering film formation, a Web coater film formation apparatus (Hirano Kotone Co., Ltd.) was used. The size of the target is 50 mm x 195 mm, and the substrate is transported by a roll-to-roll method in which a long film substrate is fed out, sputtered at the can roll position via the guide roll, and wound again via the guide roll went. The sputtering power source was formed by DC discharge (AE company MDX-10K, ENI company RPG-100).

  High refractive index layer (1) / oxide layer (1) / conductive layer / oxide layer (2) / high refractive index layer (2) / oxide layer (1) / Conductive layer / oxide layer (2) / high refractive index layer (2) / oxide layer (1) / conductive layer / oxide layer (2) / high refractive index layer (2) / oxide layer (1) / Four electromagnetic wave shielding films were formed in the order of conductive layer / oxide layer (2) / high refractive index layer (1). Detailed film forming conditions are shown in Table 1.

  The high refractive index layer (1) and the high refractive index layer (2) were formed by DC discharge using niobium oxide (NS-NBO manufactured by Asahi Glass Ceramics Co., Ltd.) as a target. The oxide layer (1) and the oxide layer (2) were formed by DC discharge with a target obtained by adding 3% by mass of aluminum oxide to zinc oxide (manufactured by Asahi Glass Ceramics). The conductive layer was formed by DC discharge using 99.9 atomic% of silver as a target.

  In addition, the content rate of zinc and aluminum in the oxide layer of the obtained electromagnetic wave shielding laminate is substantially the same as the content rate of zinc and aluminum contained in the target.

The film formation speed was adjusted by the conveyance speed of the base material. In the case of a material having a low film formation speed, the reciprocal film formation was repeated several times to obtain a desired film thickness. The film thickness was measured using a stylus- ^type film thickness meter (Dektak ^3st ULVAC agency). Table 1 shows the obtained film thickness results.

<Evaluation>
(1) Visible light transmittance The visible light transmittance of the obtained electromagnetic wave shielding laminate was measured using a Model 304 transmittance meter manufactured by Asahi Spectroscopic Co., Ltd. The measurement results of visible light transmittance are shown in Table 2 below.
(2) Resistance Value The resistance value of the obtained electromagnetic wave shielding laminate was measured using a 717 conductance monitor manufactured by DELCOM. The measurement results of the resistance value are shown in Table 2 below.
(3) Moisture resistance The NaCl test was used for moisture resistance evaluation. First, 1 μl of a 2 mass% NaCl aqueous solution was dropped on the electromagnetic wave shielding film of the electromagnetic wave shielding laminate, and then dried. Then, a PET film (thickness 100 μm) with an adhesive (ADC2 made by Polatechno Co., Ltd. or PTR2500 made by Arisawa Manufacturing Co., Ltd., thickness 25 μm) is laminated on the electromagnetic shielding film, and 100 ° C. in a constant temperature and humidity chamber with a temperature of 60 ° C. and a relative humidity of 95%. After storing for a period of time, it was taken out and the PET film was peeled off. The area of the part which deteriorated and peeled was measured with calipers. The measurement results of the deteriorated area are shown in Table 2 below.

[Comparative Example 1]
Without forming the oxide layer (1) on the high refractive index layer (1), a conductive layer was formed directly on the high refractive index layer (1) under the same film forming conditions as in Example 1. Other than that was carried out similarly to Example 1, and produced the electromagnetic wave shielding laminated body.
With respect to the obtained electromagnetic wave shielding laminate, the visible light transmittance, resistance value, and moisture resistance were evaluated in the same manner as in Example 1. The measurement results of visible light transmittance, resistance value, and moisture resistance are shown in Table 2 below.

[Comparative Example 2]
Without forming the oxide layer (1) and the oxide layer (2), a conductive layer is formed directly between the high refractive index layer (1) and the high refractive index layer (2) as in Example 1. Formed under conditions. Other than that was carried out similarly to Example 1, and produced the electromagnetic wave shielding laminated body.
With respect to the obtained electromagnetic wave shielding laminate, the visible light transmittance, resistance value, and moisture resistance were evaluated in the same manner as in Example 1. The measurement results of visible light transmittance, resistance value, and moisture resistance are shown in Table 2 below.

  When the results of Example 1 and Comparative Example 1 were compared, it was confirmed that Example 1 was a good electromagnetic wave shielding laminate, with visible light transmittance and resistance almost the same as Comparative Example 1. Moreover, about the deterioration area by a NaCl test, the deterioration area of Example 1 is 1/6 of the deterioration area of the comparative example 1, and it was confirmed that Example 1 is excellent in moisture resistance. Moreover, from this result, it was confirmed that the moisture resistance of the electromagnetic wave shielding film is improved by forming the oxide layer (1) between the high refractive index layer (1) and the conductive layer.

  Next, when the results of Example 1 and Comparative Example 2 were compared, Example 1 had substantially the same visible light transmittance and resistance value as Comparative Example 2, but the deterioration area by the NaCl test The deterioration area of 1 was 1/38 of the deterioration area of Comparative Example 2, and it was confirmed that Example 1 was excellent in moisture resistance. From this result, it was confirmed that the presence of the oxide layer (1) and the oxide layer (2) greatly contributes to the improvement of the moisture resistance of the electromagnetic wave shielding film.

  From the above results, it was confirmed that the electromagnetic wave shielding laminate obtained in Example 1 was an electromagnetic shielding laminate having high visible light transmittance, low resistance, and excellent moisture resistance.

[Example 2]
An electromagnetic wave shielding laminate was produced in the same manner as in Example 1 except that the film formation conditions were as shown in Table 3.
The obtained electromagnetic wave shielding laminate was evaluated for moisture resistance in the same manner as in Example 1. Table 6 shows the measurement results of moisture resistance.

[ Reference Example 1 ]
An electromagnetic wave shielding laminate was produced in the same manner as in Example 1 except that the film formation conditions were as shown in Table 4.
The high refractive index layers (1) and (2) were formed by DC discharge using a reduced titanium oxide (TXO) target (manufactured by Asahi Glass Ceramics).
The obtained electromagnetic wave shielding laminate was evaluated for moisture resistance in the same manner as in Example 1. Table 6 shows the measurement results of moisture resistance.

[Comparative Example 3]
Example 1 except that the film formation conditions are as shown in Table 5 and AZO layers (refractive index: 1.93) (1) and (2) are used instead of the high refractive index layers (1) and (2). In the same manner, an electromagnetic wave shielding laminate was prepared.
The AZO layers (1) and (2) were formed by DC discharge using a target obtained by adding 3% by mass of aluminum oxide to zinc oxide (manufactured by Asahi Glass Ceramics).
In addition, the content rate of zinc and aluminum in the oxide layer of the obtained electromagnetic wave shielding laminate is substantially the same as the content rate of zinc and aluminum contained in the target.
The obtained electromagnetic wave shielding laminate was evaluated for moisture resistance in the same manner as in Example 1. Table 6 shows the measurement results of moisture resistance.

In Example 2 using niobium oxide as the material for the high refractive index layer and Reference Example 1 using titanium oxide as the material for the high refractive index layer, only the periphery where NaCl was dropped was deteriorated and the deterioration area was small. . When niobium oxide and titanium oxide were compared, the degradation area was smaller in niobium oxide and the durability was better. In Comparative Example 3 in which an AZO layer was used instead of the high refractive index layer, not only the periphery where NaCl was dropped was deteriorated, but also cracks were generated over a wide area of the film formation surface from the dropped portion, and the deterioration area was increased.

  The electromagnetic wave shielding laminate of the present invention is useful as a filter for a display device or the like.

It is a schematic sectional drawing which concerns on one Embodiment of the electromagnetic wave shielding laminated body of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic wave shielding laminated body 2 Base material 31 1st high refractive index layer 32 1st oxide layer 33 Conductive layer 34 2nd oxide layer 35 2nd high refractive index layer 100 Electromagnetic wave shielding film 200 Collectively Filmed high refractive index layer

Claims (7)

An electromagnetic wave shielding laminate in which three or more electromagnetic wave shielding films are laminated on a transparent substrate,
The electromagnetic wave shielding film is a first high refractive index layer made of a material having a refractive index of 2.0 or more in order from the base material side,
A first oxide layer mainly composed of zinc oxide;
Having a conductive layer mainly composed of silver and a second high refractive index layer made of a material having a refractive index of 2.0 or more,
The first and second high refractive index layers are layers mainly composed of niobium oxide;
A second oxide layer between the conductive layer and the second high refractive index layer;
Geometrical film thickness of the first oxide layer is much larger than the geometrical thickness of the second oxide layer,
The electromagnetic wave shielding laminate, wherein the geometric thickness of the first oxide layer is 2 nm or more and 10 nm or less . 2. The electromagnetic wave shielding laminate according to claim 1, wherein the geometric thickness of the second oxide layer is 1 nm or more and 6 nm or less. The electromagnetic wave shielding laminate according to claim 1 or 2, wherein a silver content in the conductive layer is 99.8 atomic% or more. The electromagnetic wave shielding laminate according to any one of claims 1 to 3, wherein the second oxide layer is an oxide layer containing zinc oxide as a main component. An electromagnetic wave shielding laminate in which three or more electromagnetic wave shielding films are laminated on a transparent substrate,
The electromagnetic wave shielding film is a first high refractive index layer made of a material having a refractive index of 2.0 or more in order from the base material side,
A first oxide layer mainly composed of zinc oxide;
A conductive layer mainly composed of silver and a second high-refractive-index layer made of a material having a refractive index of 2.0 or more, and the first high-refractive-index layer in direct contact with the electromagnetic wave shielding film, The second high refractive index layer consists of one layer formed in a batch,
The first and second high refractive index layers are layers mainly composed of niobium oxide;
A second oxide layer between the conductive layer and the second high refractive index layer;
Geometrical film thickness of the first oxide layer is much larger than the geometrical thickness of the second oxide layer,
The electromagnetic wave shielding laminate, wherein the geometric thickness of the first oxide layer is 2 nm or more and 10 nm or less . 6. The electromagnetic wave shielding laminate according to claim 5 , wherein the geometric thickness of the second oxide layer is 1 nm or more and 6 nm or less. A display screen for displaying images,
Display device, characterized in that it comprises an electromagnetic wave shielding laminate according to any one of claims 1 to 6 provided on the viewing side of the display screen.

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