JP2000329934A - Transparent electrically conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film having excellent durability and an electromagnetic wave shielding property. SOLUTION: In this transparent electrically conductive film, a transparent electrically conductive thin film layer comprising a transparent thin film layer B having high refractive index and a metallic thin film layer C including at least silver is laminated 3-5 times repeatedly by using B/C as a repeating unit on one main surface of a transparent base body and, further, the transparent electrically conductive thin film layer B having high refractive index is formed on the uppermost layer. Therein, the metallic thin film layer C1, at least, nearest to a base body is made to be a metallic thin film containing >=99 wt.% silver and the metallic thin film layer C2, at least, most remote to the base body is made to be a silver alloy thin film layer containing 60-95 wt.% silver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a transparent conductive film. For details, see Plasma Display (PD
P), cathode ray tube (CRT), liquid crystal display (LCD)
The present invention relates to a transparent conductive film useful as an electromagnetic wave filter capable of efficiently reducing electromagnetic waves generated from a display such as a display.

[0002]

2. Description of the Related Art In recent years, society has become highly computerized. As a result, the technology for information-related equipment and related parts has remarkably advanced and spread.
Among them, display devices are used for televisions, personal computers, for displaying guidance at stations and airports, and for providing various other types of information. Display devices have been required to have various characteristics in order to be used for such various applications, and in particular, have been required to be large and thin. In these demands, a plasma display has attracted attention as a large and thin display. However, the plasma display has a problem of generating a strong leakage electromagnetic field due to a problem in principle. In recent years, the influence of the leaked electromagnetic field has been particularly concerned, and it is particularly necessary to prevent the influence on the human body and other electronic devices. Further, from the plasma display device, there is a possibility that near infrared light generated from excited atoms in the plasma acts on electronic devices such as a cordless phone and a remote controller to cause a malfunction.

For this reason, display devices, especially PDPs
Uses a filter (electromagnetic wave filter) for shielding a leakage electromagnetic field and near-infrared light. In general, as a configuration of the electromagnetic wave filter, an electromagnetic wave shielding layer is formed on one side of the support plate, and further, the other side of the support plate,
And an antireflection layer formed on the surface of a plastic film on which an electromagnetic wave shielding layer is formed. These members are bonded together and combined by a method such as coating to form a P
Used as DP optical filter.

At present, the near-infrared ray and the electromagnetic field shielding material of the electromagnetic wave filter are roughly classified into a grounded metal mesh or a mesh of synthetic resin or metal fiber coated with a metal, and a near infrared ray absorbing material. There are a combination of a dye and a combination of a transparent conductive thin film typified by indium tin oxide (ITO) and a dye that absorbs near infrared rays (in some cases).

[0005] For example, Japanese Patent Application Laid-Open No. 9-33
Japanese Patent No. 0667 discloses an electromagnetic wave shield plate formed by applying a conductive paste in a mesh shape on a transparent resin plate and drying the paste. In addition, as an example of
A high refractive index transparent thin film layer (D) and a metal thin film layer (E) are sequentially formed on one main surface of a transparent polymer film described in JP-A No. 0-73719 (D) / (E). An optical filter for a display in which a light control film in which a high refractive index transparent thin film layer (D) and a transparent resin layer are further laminated thereon, which are repeatedly laminated four or more times as a repeating unit, is exemplified. When these electromagnetic wave shielding layers are used, it is possible to efficiently shield electromagnetic waves and near infrared rays generated from the housing. In particular, in the latter example, a transparent conductive thin film is used as the electromagnetic wave shielding layer, and there is no generation of a light-shielding portion or moiré by the mesh as compared with the former, which is particularly preferable. These electromagnetic wave shielding layers themselves are used together with a supporting plate such as a glass plate or a plastic plate due to insufficient mechanical strength.

[0006] Of these, a laminate of a high refractive index thin film layer represented by a metal oxide such as ITO and a metal thin film layer containing silver as a main component has high transparency and high surface resistivity. And has a good electromagnetic wave shielding function. However, in the case of a substrate in which the high-refractive-index thin film layer and the metal thin film layer are laminated, the occurrence of reflective defects mainly due to the deterioration of the silver layer, and the surface resistance value is one or more orders of magnitude higher than the metal mesh. However, problems such as insufficient electromagnetic wave shielding performance have occurred.

Various studies have been made to solve this problem, but no sufficient effect has been obtained. To solve the former problem, for example, Japanese Patent Publication No. 59-4499
As shown in Japanese Patent Publication No. 3 (1993), deterioration of the silver layer could be improved by using the silver thin film layer as a silver-gold thin film layer. However, in this case, since the resistivity of the silver-gold alloy is higher than that of silver, the surface resistivity increases, and a new problem that the electromagnetic wave shielding ability decreases is newly generated.

On the other hand, in order to solve the latter problem, the present inventors have disclosed in Japanese Patent Application Laid-Open No. 10-73718 a patent application for a transparent conductive layer comprising a laminate of a high refractive index transparent thin film layer and a metal thin film layer. It has been proposed that the surface resistivity can be further reduced while maintaining transparency by reducing the thickness of each metal thin film layer and increasing the number of repetitions of lamination. However, even in this case, the problem of deterioration of the silver layer has not been completely solved. Also,
In the present invention, it has been proposed that the deterioration of the silver layer can be prevented by protecting the peripheral end of the transparent conductive layer, but most of the deterioration of the silver layer can be suppressed by protecting the peripheral end. However, it was not always sufficient, and there was a problem of deterioration occurring from portions other than the peripheral end.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a transparent conductive film which has excellent durability and electromagnetic wave shielding properties and can be used as an electromagnetic wave shielding filter.

[0010]

Means for Solving the Problems In order to solve the above problems, the present inventors have conducted intensive studies and as a result, it has been found that the deterioration of the silver layer of the transparent conductive film in the optical filter is caused by the transparent conductive thin film at the time of lamination and coating. When the layer is exposed, dust containing substances that cause deterioration, such as chlorine, which is tiny and floats in the air when it comes into contact with the outside air, adheres to the transparent conductive layer and degrades based on the minute dust. It has been found that this problem can be solved by improving the durability of the metal thin film layer closest to the atmosphere in order to prevent the occurrence and progress of deterioration. In addition, the present invention has been found to be able to achieve low resistance which leads to good electromagnetic wave shielding ability by using other metal thin film layers, particularly the metal thin film layer closest to the transparent substrate, as a silver thin film layer. completed.

That is, the present invention provides a transparent conductive thin film layer comprising a high refractive index transparent thin film layer (B) and a metal thin film layer containing at least silver (C) on one main surface of a transparent substrate (A). Is a transparent conductive film obtained by repeatedly laminating 3 to 5 times with (B) / (C) as a repeating unit and further forming a high refractive index transparent thin film layer (B) on the uppermost layer thereof,
At least the metal thin film layer (C1) closest to the substrate is a metal thin film containing at least 99% by weight of silver, and at least the metal thin film layer (C2) farthest from the substrate is a silver alloy containing 60 to 95% by weight of silver. The transparent conductive film is a thin film layer.

In a preferred embodiment of the transparent conductive film according to the present invention, the transparent substrate (A) has a thickness of 25 to 25.
0 μm, a transparent plastic film having a total light transmittance of at least 70%, a high refractive index transparent thin film layer (B)
Is a thin film layer formed of a metal oxide or metal sulfide, and the thickness of each high refractive index transparent thin film layer (B) is 5 to 2
00 nm, and the metal thin film layer (C2)
Weight percent gold, platinum, palladium and the silver alloy thin film layer containing at least one metal selected from copper,
The thickness of each metal thin film layer (C) is 4 to 30 nm;
The surface resistivity of the transparent conductive thin film layer is 0.5 to 8 Ω / □, and the total light transmittance is at least 50%. The transparent conductive film according to the present invention has a thickness of 25 to 250 μm and a surface resistivity of 0.5 to 8 Ω / □.
It is preferred that

The transparent conductive film according to the present invention has high electromagnetic wave shielding ability and excellent environmental resistance. Therefore, plasma display (PDP), CRT (C
RT) and a filter for shielding electromagnetic waves of a display such as a liquid crystal display (LCD).

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The transparent conductive film of the present invention comprises a transparent substrate (A)
A transparent conductive thin film layer composed of a high refractive index transparent thin film layer (B) and a metal thin film layer containing at least silver (C) is formed on one main surface of the base material by using (B) / (C) as a repeating unit. It is manufactured by repeatedly laminating five times, and further laminating a high refractive index transparent thin film layer (B) on the uppermost layer.

The transparent substrate (A) used in the present invention includes a glass plate and a transparent plastic film. In the present invention, a transparent plastic film is preferably used. The transparent plastic film is not particularly limited as long as it is transparent. For example, polyethylene terephthalate, polyether sulfone, polyarylate,
Examples include a homopolymer such as polyacrylate, polycarbonate, polyetheretherketone, polyethylene, polyester, polypropylene, polyamide, and polyimide, and a polymer film composed of a copolymer of a monomer of these resins with a copolymerizable monomer.

As a method for forming the transparent plastic film, a known plastic film manufacturing method such as a melt extrusion method, a casting method, and a calendar method can be used. In general, the transparent conductive thin film layer is colored in both the transmission color and the reflection color, and may have an undesirable color. In order to correct the color at that time, the transparent plastic film can be colored. As a method of coloring, a method of forming a film after previously mixing with a dye when forming the plastic film, a method of dispersing the dye in a resin to form an ink, coating and drying, a method of bonding a colored plastic film, and the like Is mentioned.

The total light transmittance of the transparent plastic film is preferably 70% or more. It is more preferably at least 75%, most preferably at least 80%. Although there is no particular limitation on the thickness of the transparent plastic film, 25 to 2
It is preferably 50 μm. For the purpose of improving the adhesion with the electromagnetic wave shielding layer, on the surface on which the transparent conductive thin film layer is formed as the electromagnetic wave shielding layer, for example, to improve the adhesion of an aqueous polyurethane-based or silicon-based coating agent, etc. It is also possible to form an underlayer.

In the present invention, it is preferable to use a transparent conductive thin film as the electromagnetic wave shielding layer. Unlike a metal mesh, the transparent conductive thin film covers the entire electromagnetic wave shielding surface, and does not reduce the display resolution of the display. It also has near-infrared reflectivity,
Furthermore, it has many excellent features such as being able to be processed in a roll shape, and can be an electromagnetic wave shielding layer that well matches the purpose of the present invention.

Usually, as the electromagnetic wave shielding layer, in addition to the above, there is a metal mesh or a material in which a conductive paste in which a metal is dispersed in a resin is applied in a mesh shape and dried.
However, the metal mesh itself is not preferable because it does not transmit light, so that a portion that does not transmit light appears, moire occurs, a disconnection portion occurs when forming the mesh, and the yield deteriorates.

The transparent conductive thin film as the electromagnetic wave shielding layer is preferably formed on one surface of a transparent plastic film. If it is formed on both surfaces, it is difficult to ground the electromagnetic wave shielding layer, which is not preferable. The transparent conductive thin film used in the present invention preferably comprises a high refractive index thin film layer (B) and a metal thin film layer (C). Indium-tin oxide (ITO) generally known as a transparent conductive thin film
When a metal oxide-based transparent conductive thin film layer such as zinc oxide (ZnO) or the like is used alone, it is necessary to increase the thickness of the thin film layer in order to lower the surface resistance, in which case the total light transmittance is greatly reduced. Not preferred. Further, a high refractive index transparent thin film layer (B)
And the metal thin film layer (C) are preferably repeatedly laminated. In this case, the outermost layer (the layer farthest from the transparent substrate)
Is preferably a high refractive index transparent thin film layer (B). When the outermost surface layer is a metal thin film layer (C), a direct reflection interface is formed between the air layer or the resin layer and the metal layer, so that light reflection is increased and light transmittance is greatly reduced. Not preferred. In addition, the metal layer is directly exposed to the outside air, and the deterioration of the metal layer proceeds, which is not preferable from this viewpoint.

First, a high-refractive-index transparent thin film layer (B) is formed on one main surface of the transparent plastic film.
A metal thin film layer (C) is formed on the surface of the high refractive index transparent thin film layer (B). (B) / (C) are sequentially formed as a repeating unit. The number of repetitions is preferably 3 to 5 times. If the number of repetitions is more than the above range,
An error in the thickness of each layer greatly affects the accuracy of the entire optical characteristics, and furthermore, the productivity is deteriorated, which is not preferable. If the number of repetitions is less than the above range, the thickness of each metal thin film layer must be increased in order to effectively shield electromagnetic waves. In this case, since the reflection intensity is increased, the total light transmittance is significantly reduced, and it is difficult to achieve the required optical characteristics, which is not preferable.

The transparent conductive thin film layer used in the present invention preferably has a surface resistivity of 0.5 to 8 Ω / □. 0.7
More preferably, it is 4 Ω / □. When the surface resistivity is within the above range, it is possible to achieve both good shield characteristics and optical characteristics. If the surface resistivity is lower than the above range, the electromagnetic wave shielding characteristics themselves are good, but the light transmittance is undesirably reduced, which is not preferable. If the surface resistivity is higher than the above range,
Although the optical characteristics are improved, the electromagnetic wave shielding characteristics are deteriorated, which is not preferable.

The total light transmittance of the transparent conductive thin film layer is preferably 50% or more. It is more preferably at least 60%, most preferably at least 65%. It is not preferable to mount an electromagnetic wave filter using a transparent conductive thin film layer having a total light transmittance lower than the above value on a display because a screen becomes dark.

As described above, in the present invention, the metal thin film layer (C) is partially used as the transparent conductive thin film layer. Therefore, even if the thicknesses of the metal thin film layer (C) and the high-refractive-index transparent thin film layer (B) are optically optimized, the absorption and reflection of metal light by the metal thin film layer (C) cannot be avoided. Therefore, the total light transmittance of the transparent conductive thin film layer used in the present invention is 80%.
Is generally not exceeded.

High refractive index transparent thin film layer (B) used in the present invention
The material is not particularly limited, but is preferably a material having a refractive index of 1.6 or more, more preferably 1.8 or more. Specific materials that can form such a high-refractive-index transparent thin film layer (B) include indium, titanium, zirconium, bismuth, tin, zinc, antimony, tantalum, cerium, neodymium, lanthanum,
Oxides such as thorium, magnesium, and gallium, mixtures of these oxides, composite oxides, zinc sulfide, and the like can be given. These oxides or sulfides may have a difference in the stoichiometric composition between the metal and oxygen or sulfur as long as the optical characteristics are not significantly changed. Among these materials, indium oxide, indium-tin oxide (IT
O) and tin oxide can be preferably used because they have high transparency and a high refractive index, and also have a high film-forming speed and good adhesion to a metal thin film layer.

The thickness of the high-refractive-index transparent thin film layer (B) is determined from the required optical characteristics and is not particularly limited, but the thickness of each layer is preferably 5 to 200 nm. 10-100 nm is more preferred. As described above, the high-refractive-index transparent thin film layer (B) is repeatedly laminated and used with the metal thin-film layer (C), but each high-refractive-index transparent thin film layer (B) needs to be made of the same material. There is no need to have the same thickness. As a method for forming the high-refractive-index transparent thin film layer (B), known methods such as a sputtering method, an ion plating method, an ion beam assist method, a vacuum evaporation method, and a wet coating method can be used. Of these, the sputtering method is preferred.

Further, as the material of the metal thin film layer (C),
It is preferable that the metal layer be a single silver metal or a metal layer containing at least silver. Silver can be preferably used because of its low surface resistivity, good infrared reflection characteristics, and excellent visible light transmission characteristics when laminated with the high refractive index transparent thin film layer (B). However, since silver has poor chemical and physical stability, it is easily degraded by environmental pollutants, moisture, heat and light. When a silver thin film layer is repeatedly laminated and used as used in the present invention, the metal layer farthest from the base is preferably formed of a silver alloy.
By using at least the metal thin film layer (C2) farthest from the substrate as the silver alloy layer, it is possible to suppress the deterioration of the previously extended silver layer. When the deterioration of the metal thin film layer (C2) farthest from the substrate is suppressed, the deterioration of the metal thin film layer (C) closer to the substrate than (C2) does not progress, so that the entire transparent conductive thin film does not deteriorate.

The silver alloy is preferably an alloy of silver and one or more environmentally stable metals such as gold, platinum, palladium and copper. The composition of the silver alloy affects the surface resistivity, environmental resistance, and the like of the metal thin film layer (C2). That is, if the proportion of silver is too low, the surface resistivity increases. If the proportion of silver is too high, the environmental resistance decreases. In view of this, in the present invention, a silver alloy having a silver content of 60 to 95% by weight is preferable. In this case, the other component of the silver alloy is preferably gold, platinum, palladium, copper, or the like, or a mixed metal thereof. And their composition ratio is 5
Preferably it is 40% by weight.

On the other hand, it is preferable that at least the metal thin film layer (C1) closest to the base is made of silver metal alone. Silver alone refers to a case containing 99% by weight or more of silver. As is generally known, it is impossible to refine the silver content to 100% by weight, and the silver content does not exceed 99.9999% by weight. Since the silver thin film has a low surface resistivity as described above, it is possible to achieve a low surface resistivity that leads to a good electromagnetic wave shielding ability even when used as a transparent conductive thin film layer in the present invention. Become. By forming the metal thin film layer (C1) closest to the base with silver alone, it can be used without any problem in durability.

When all the metal thin film layers (C) are made of a silver alloy in the same manner as the (C2) layer, the surface resistivity is too high. Therefore, in order to obtain a transparent conductive thin film having a desired surface resistivity, each metal thin film is required. The thickness of the layers must be increased or the number of repeated laminations must be increased. When the thickness of each metal thin film layer is increased, the transparency becomes poor, and when the number of repetitions is increased, it is not preferable for the above-mentioned reason. (C1) layer and (C
2) The other metal thin film layer (CX) other than the layer may be preferably made of either silver alone or an alloy containing at least silver.

The thickness of each metal thin film layer (C) is preferably not less than 4 nm because it is preferably not an island structure. From the viewpoint of transparency, the thickness is preferably 30 nm or less. However, even if the thickness exceeds this range, the filter can be used without any problem when the total light transmittance of the filter is 40% or more. As in the case of the high-refractive-index transparent thin-film layer (B), the thickness of each metal thin-film layer (C) does not need to be the same, and the thickness of each metal thin-film layer (C) does not need to be the same. The metal thin film layer (CX) does not need to be made of the same material.

As the method for forming the metal thin film layer (C), the above-described method for forming the high refractive index transparent thin film layer (B) can be used as it is. Further, it is also possible to seal the peripheral end portion of the transparent conductive thin film layer for the purpose of preventing deterioration of the transparent conductive thin film layer, particularly, the metal thin film layer. For example, a triazineamine-based compound, a thiodipropionate-based compound, a benzimidazole-based compound alone, or a transparent resin containing these compounds can be used for the above purpose.

The transparent conductive film according to the present invention produced as described above preferably has a total light transmittance of 40% or more. It is more preferably at least 50%, most preferably at least 60%. When the total light transmittance is lower than the above value, when this is used as a filter for shielding electromagnetic waves, the display screen becomes dark, which is not preferable. In addition, since a metal thin film layer is used for the transparent conductive thin film used in the present invention, the total light transmittance does not generally exceed 78%. The overall thickness is about 25 to 250 μm, and the surface resistivity is 0.5 to 8
It is about Ω / □.

[0034]

The present invention will be described below with reference to examples. Evaluation items and evaluation methods were performed as follows.

(1) Total light transmittance (%) Using a spectrophotometer [manufactured by Hitachi, Ltd., product name: U-3500 type], arbitrary five points of each of the obtained samples were measured. The average value was used.

(2) Surface resistivity (%) Using a four-probe surface resistivity measuring device [manufactured by Mitsubishi Chemical Corporation, product name: Loresta SP], arbitrary 10 points of each sample obtained were measured. It measured and the average value was used.

(3) Environmental resistance (hr) The time until a reflective defect occurred in salt water was measured. The salt water is sodium chloride (manufactured by Wako Pure Chemical Industries) 1.8
g was dissolved in 1000 ml of pure water. Each of the obtained samples was cut out to 100 mm × 100 mm, and 23
The sample was stored in the above-mentioned salt water at ℃, and the time until the occurrence of a defect having a diameter of 0.1 mm or more was measured.

Example 1 Polyethylene terephthalate (PET) having a thickness of 75 μm
Film (Toyobo Co., Ltd., product name: A-410
0) has a laminated structure of indium oxide thin film / silver thin film / indium oxide thin film / silver thin film / indium oxide thin film / silver-gold alloy thin film / indium oxide thin film on one main surface from the PET film side. 40/10/8
A transparent conductive thin film layer having a thickness of 0/10/80/10/40 nm was laminated to obtain a transparent conductive film. The total light transmittance, surface resistivity, and environmental resistance of the obtained transparent conductive film were measured by the above methods, and the results are summarized in [Table 1].
The indium oxide thin film was formed by using metal indium as a target, evacuating to a pressure of 0.01 Pa, introducing argon gas until the total pressure reached 0.18 Pa, and further reducing the total pressure to 0.1 Pa. Oxygen gas was introduced at 26 Pa. In this state, a magnetron DC sputtering method was used. The silver thin film was formed by using a simple substance of silver (silver content: 99.99% by weight) as a target, evacuating to a pressure of 0.01 Pa, and then reducing the total pressure to 0.1 Pa.
Argon gas was introduced until the pressure became 18 Pa. In this state, a magnetron DC sputtering method was used. Further, the silver-gold alloy thin film was formed in the same manner as the silver thin film except that an alloy target having a silver content of 90% by weight and a gold content of 10% by weight was used.

Example 2 The transparent conductive layer had a laminated structure of indium oxide thin film / silver thin film / indium oxide thin film / silver-gold alloy thin film / indium oxide thin film / silver-gold alloy thin film / indium oxide thin film from the PET film side. Each thickness is 40/10/8
A transparent conductive film was obtained in the same manner as in Example 1, except that the thickness was changed to 0/10/80/10/40 nm. Silver used-
The contents of silver and gold in the gold alloy thin film are the same as in Example 1. Total light transmittance of the obtained transparent conductive film,
Surface resistivity. The environmental resistance was measured in the same manner as in Example 1. The results are shown in Table 1.

Example 3 The transparent conductive layer had a laminated structure of indium oxide thin film / silver thin film / indium oxide thin film / silver thin film / indium oxide thin film / silver-palladium thin film / indium oxide thin film from the PET film side. 40/10/80 /
A transparent conductive film was obtained in the same manner as in Example 1 except that the thickness was 10/80/10/40 nm. The total light transmittance, surface resistivity, and environmental resistance of the obtained transparent conductive film were measured in the same manner as in Example 1. The results are shown in Table 1. The formation of the silver-palladium thin film was performed in the same manner as the formation of the silver thin film, except that an alloy target containing 75% by weight of silver and 25% by weight of palladium was used as the target.

Comparative Example 1 The transparent conductive layer had a laminated structure of indium oxide thin film / silver thin film / indium oxide thin film / silver thin film / indium oxide thin film / silver thin film / indium oxide thin film from the PET film side. 10/80/10/80 /
A transparent conductive film was obtained in the same manner as in Example 1 except that the thickness was changed to 10/40 nm. The total light transmittance, surface resistivity, and environmental resistance of the obtained transparent conductive film were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 The transparent conductive layer was formed from the PET film side in a laminated structure of indium oxide thin film / silver-gold alloy thin film / indium oxide thin film / silver-gold alloy thin film / indium oxide thin film / silver-alloy gold thin film / indium oxide thin film. Consisting of 40 /
A transparent conductive film was obtained in the same manner as in Example 1, except that the thickness was 10/80/10/80/10/40 nm.
The silver and gold contents of the silver-gold alloy thin film are the same as in Example 1. The total light transmittance, surface resistivity, and environmental resistance of the obtained transparent conductive film were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 A transparent conductive material was prepared in the same manner as in Example 1 except that the silver content was 97% by weight and the gold content was 3% by weight. A functional film was obtained.
The total light transmittance, surface resistivity, and environmental resistance of the obtained transparent conductive film were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 4 A transparent conductive material was prepared in the same manner as in Example 1 except that the target used in forming the silver-gold alloy thin film layer was 50% by weight of silver and 50% by weight of gold. A functional film was obtained.
The total light transmittance, surface resistivity, and environmental resistance of the obtained transparent conductive film were measured in the same manner as in Example 1. The results are shown in Table 1.

[0045]

[Table 1]

[0046]

The transparent conductive film according to the present invention comprises:
High electromagnetic wave shielding performance and excellent environmental resistance. Therefore, a plasma display (PDP), a cathode ray tube (C
RT), useful as a filter for shielding electromagnetic waves of a display such as a liquid crystal display (LCD).

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Suzuki 2-1-1 Tango-dori, Minami-ku, Nagoya-shi, Aichi Prefecture Inside Mitsui Chemicals, Inc. (72) Inventor Akemi Nakajima 2-1-1, Tango-dori, Minami-ku, Nagoya-shi, Aichi Prefecture Mitsui Chemicals Co., Ltd. AA16 BB02 BB06 BB12 GG33 HH02 HH12 KK07

Claims (9)

[Claims] 1. A transparent conductive thin film layer comprising a high-refractive-index transparent thin film layer (B) and a metal thin film layer containing at least silver (C) on one main surface of a transparent substrate (A). / (C)
Is a transparent conductive film formed by repeatedly laminating 3 to 5 times as a repeating unit and further forming a high refractive index transparent thin film layer (B) on the uppermost layer, wherein the metal thin film layer (C1) is at least closest to the substrate. Is a metal thin film containing 99% by weight or more of silver, and at least the metal thin film layer (C2) farthest from the substrate is a silver alloy thin film layer containing 60 to 95% by weight of silver. Film. 2. The transparent substrate (A) has a thickness of 25 to 250.
The transparent conductive film according to claim 1, wherein the transparent conductive film is a transparent plastic film having a total light transmittance of at least 70%. 3. The transparent conductive film according to claim 1, wherein the high refractive index transparent thin film layer (B) is a thin film layer formed of a metal oxide or a metal sulfide. 4. The transparent conductive film according to claim 3, wherein the metal oxide is at least one metal oxide selected from indium-tin oxide, indium oxide, and tin oxide. 5. The thickness of each high refractive index transparent thin film layer (B) is 5
The transparent conductive film according to claim 1, wherein the thickness is from 200 to 200 nm. 6. The metal thin film layer (C2) is 5 to 40% by weight.
The transparent conductive film according to claim 1, wherein the transparent conductive film is a silver alloy thin film layer containing at least one metal selected from the group consisting of gold, platinum, palladium, and copper. 7. The thickness of each metal thin film layer (C) is 4 to 30 n.
2. The transparent conductive film according to claim 1, wherein m is m. 8. The transparent conductive thin film layer has a surface resistivity of 0.5.
The transparent conductive film according to claim 1, wherein the total light transmittance is at least 50%. 9. The transparent conductive film has a thickness of 25 to 25.
The transparent conductive film according to claim 1, wherein the transparent conductive film has a surface resistivity of 0.5 to 8 Ω / □.