JP2003178626A - Transparent conductive film and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent conductive film not only having high transparency and excellent in electromagnetic wave shielding effect and antistatic effect but also having natural hue of a transmitted image and excellent in durability represented by saline water resistance, and to provide a display device with the transparent conductive film formed on the screen thereof. <P>SOLUTION: This transparent conductive film formed on the screen of the display device is formed by applying and drying a paint containing at least platinum group metal fine particles having an average particle diameter of 50 nm or less and thereafter burning it at a burning temperature of 300-1,000°C, and has a transparent conductive layer formed by converting at least a part of the platinum metal into a platinum group metal oxide. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a transparent and excellent antistatic effect and electromagnetic wave shielding effect, particularly when used for a display surface such as a cathode ray tube or a plasma display, and has a large film strength, salt water resistance and oxidation resistance. The present invention relates to a transparent conductive film which has good durability such as heat resistance and ultraviolet resistance, has a natural hue of a transmitted image and good visibility, and a display device having the transparent conductive film formed on a display surface.

[0002]

2. Description of the Related Art Currently, cathode ray tubes used as TV cathode ray tubes and computer displays display characters and images on a display surface by projecting an electron beam onto a fluorescent surface that emits red, green and blue light. Since the static electricity generated on the display surface causes dust to adhere to the display surface, the visibility is deteriorated and electromagnetic waves may be emitted to affect the environment. In addition, the possibility of static electricity generation and electromagnetic wave radiation has been pointed out in plasma displays, which are recently being applied as wall-mounted televisions.

In order to solve these problems of static electricity generation and electromagnetic radiation, conventionally, a transparent metal thin film is formed on the display surface of a display device by a sputtering method or a vapor deposition method, or fine particles of silver, gold or the like. The coating liquid in which is dispersed in the liquid is applied to the display surface to form a transparent conductive film, whereby antistatic property and / or electromagnetic wave shielding is achieved. In addition, when these thin films are formed on the display surface, interface reflection occurs and visibility deteriorates. Therefore, in order to prevent this, an upper layer and / or a lower layer of the transparent conductive film has a different refractive index from this. Lamination of transparent thin films is also practiced.

For example, Japanese Patent Laid-Open No. 8-77832 discloses that
As a transparent conductive film having an excellent electromagnetic wave shielding effect and an antireflection effect, there has been proposed a transparent conductive thin film made of metal fine particles having an average particle diameter of 2 to 200 nm and containing at least silver, and a transparent coating film having a different refractive index. There is.

[0005]

According to these methods, although antistatic effect and electromagnetic wave shielding effect can be expected, when silver is used as a metal, absorption at a specific wavelength of transmitted light depends on its light transmission spectrum. Occurs, the conductive film is colored and the hue of the transmitted image looks unnatural, the film is soft and scratches are likely to occur, and silver is altered when exposed to salt water, and the surface of the conductive film Since the resistance value increases and the electromagnetic wave shielding effect decreases, there is a problem such as poor durability particularly in a place exposed to salt fog such as the coast, which makes practical application difficult. The present invention has been made to solve the above problems, and therefore the object is to have a transparent and excellent antistatic effect and electromagnetic wave shielding effect, and has a large film strength and is represented by salt water resistance. Another object of the present invention is to provide a transparent conductive film which has good durability and good transparency, and which has a natural hue of a transmitted image and good visibility, and a display device having the transparent conductive film formed on a display surface.

[0006]

In order to solve the above-mentioned problems, the present invention provides a method according to claim 1, wherein the average particle size is 50 nm.
The following coating material containing at least platinum group metal fine particles is applied,
Provided is a transparent conductive film having a transparent conductive layer formed by baking at a baking temperature in the range of 300 ° C. to 1000 ° C. after being dried, and having at least a part of the platinum group metal converted to a platinum group metal oxide. To do. In the above, the transparent conductive layer is composed of a platinum group metal and a platinum group metal oxide in a total amount of 10
It is preferable that the content is at least wt%. The platinum group metal is preferably at least ruthenium.
The platinum group metal oxide is preferably at least ruthenium oxide. In the above, at least one transparent thin film having a refractive index different from the refractive index of the transparent conductive layer is preferably provided in the upper layer and / or the lower layer of the transparent conductive layer. The outermost layer of the transparent conductive film is preferably provided with a transparent thin film having irregularities. It is preferable that at least one layer of the transparent conductive film contains a coloring material. The present invention also provides the display device according to claim 8, wherein any one of the above transparent conductive films is formed on a display surface.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below. The present inventors have been earnestly researching for a transparent conductive film which can be used for a display surface of a display device and is transparent, which has an excellent antistatic effect and an electromagnetic wave shielding effect and also has excellent durability, Ruthenium having an average particle size of 50 nm or less,
By applying a coating material containing fine particles of a platinum group metal consisting of palladium, platinum, rhodium, iridium or osmium to a substrate, drying and baking at a firing temperature in the range of 300 ° C to 1000 ° C, the above object is achieved. The inventors have found what can be achieved and have reached the present invention.

A coating material containing the platinum group metal fine particles having an average particle diameter of 50 nm or less is applied on a substrate, and after drying, the temperature is 300 ° C.
When baked at a temperature of up to 1000 ° C. to form a film, the total surface area of the fine particles is sufficiently large due to the small particle size of the metal fine particles, and part or all of the platinum group metal is converted to an oxide at the above baking temperature. . The platinum group metal oxide not only has a higher chemical stability represented by salt water resistance than the platinum group metal, but also does not impair the conductivity of the transparent conductive film even if an oxide is formed. If the baking temperature is less than 300 ° C., the formation of platinum group metal oxide is insufficient,
If the temperature exceeds 0 ° C, problems such as damage to the base material and deterioration of the film components occur.

Simultaneously with the formation of the oxide, in the transparent conductive film obtained by baking in the above temperature range, at least some of the metal fine particles are fused with each other to form an at least partially continuous metal thin film and / or metal oxide. A thin film is formed. Therefore, in the transparent conductive film of the present invention,
Much higher conductivity than that obtained by simply contacting the metal fine particles is obtained. As a result, not only the antistatic effect and electromagnetic wave shielding effect are excellent, but also the transparent conductive film having high transparency and durability. Is obtained. If the average particle diameter of the platinum group metal fine particles exceeds 50 nm, the oxides are not produced and the particles are not fused sufficiently, and the light absorption becomes large, and the transparency is lost when sufficient conductivity is obtained, Practicality is reduced.

The transparent conductive film preferably contains platinum group metal and platinum group metal oxide in an amount of 10% by weight or more. Generally, the conductive performance of the transparent conductive film required to exert the electromagnetic wave shielding effect in addition to the antistatic function is represented by the following formula 1. S = 50 + 10log (1 / ρf) + 1.7t√ (f / ρ) ... Formula 1 In the formula, S (dB); Electromagnetic wave shielding effect ρ (Ω-cm); Volume resistivity of conductive film f (MHz); Electromagnetic wave Frequency t (cm): The thickness of the conductive film. Here, the film thickness t is 1 μm from the viewpoint of ensuring transparency.
Since it is preferably about (1 × 10 ⁻⁴ cm) or less, the electromagnetic wave shielding effect S can be approximately represented by the following equation 2 if the term including the film thickness t in equation 1 is ignored. S = 50 + 10log (1 / ρf) ... Equation 2

Here, the larger the value of S (dB), the greater the electromagnetic wave shielding effect. Generally, the electromagnetic wave shielding effect is S>
30 dB is considered valid, and S> 60 dB is considered excellent. Further, since the frequency of electromagnetic waves to be regulated is generally in the range of 10 kHz to 1000 MHz, the volume resistivity value (ρ) of 10 ³ Ω-cm or less is required as the conductivity of the transparent conductive film. That is, the lower the volume specific resistance value (ρ) of the transparent conductive film, the more effectively electromagnetic waves in a wider range of frequencies can be shielded. In order to satisfy this condition, it is necessary that the transparent conductive film contains the platinum group metal and the platinum group metal oxide in a total amount of 10% by weight or more. When the content is less than 10% by weight, the conductivity is lowered and it becomes difficult to obtain a substantial electromagnetic wave shielding effect.

After satisfying the above conditions, the transparent conductive film has a thickness of 200 in consideration of transparency and antireflection property.
It is preferably not more than nm. The obtained transparent conductive film may be a smooth film or a film having an uneven mesh structure.

The platinum group metal used in the transparent conductive film of the present invention may be any one kind of ruthenium, palladium, platinum, rhodium, iridium and osmium, or two or more kinds, but ruthenium is particularly preferable. Among the platinum group metals, ruthenium is relatively inexpensive, has high conductivity, high chemical stability, and since metal fine particles easily fuse during film formation, it further improves conductivity while maintaining high transparency. be able to. Furthermore, ruthenium
It is easily converted to RuO ₂ by baking in the range of 300 ° C to 1000 ° C. This RuO ₂ has extremely high chemical stability and conductivity represented by salt water resistance, and since there is no light absorption peak of a specific wavelength in the visible light region of 400 nm to 700 nm in hue, the transmitted image looks unnatural. It has the advantage of not being colored. Further, the transparent conductive film formed by converting at least ruthenium oxide has an optimized refractive index, which is preferable in terms of antireflection performance. The existing state of ruthenium and ruthenium oxide in the transparent conductive film may be in the form of fine particles, or may be a state in which particles are fused with each other and are at least partially continuous.

The transparent conductive film of the present invention contains, in addition to the above-mentioned platinum group metal and platinum group metal oxide, other components, if necessary, for the purpose of further improving film strength, conductivity and transparency.
For example, fine particles of oxides or complex oxides of silicon, aluminum, zirconium, cerium, titanium, yttrium, zinc, magnesium, indium, tin, antimony, gallium, etc., metal fine particles of silver, gold, copper, nickel, etc., and silicon. A hydrolyzate of a metal alkoxide such as titanium or zirconium, an inorganic binder component such as a silicone monomer or a silicone oligomer, and the like may be appropriately contained.

The above-mentioned coating material containing at least platinum group metal fine particles is mixed with the above-mentioned platinum group metal aqueous sol and, if necessary, other component aqueous sol, preferably together with alcohol, and the resulting mixed solution is subjected to an ultrasonic dispersion machine. It can be easily prepared by dispersing using, for example. To apply this paint on a substrate, any ordinary thin film coating technique such as spin coating, roll coating, spraying, bar coating, dipping, meniscus coating, or gravure printing can be used. is there. Among them, the spin coating method is a particularly preferable coating method because a thin film having a uniform thickness can be formed in a short time. After coating, dry the coating film at 300 ℃
By baking at a baking temperature in the range of up to 1000 ° C., a transparent conductive film formed by converting at least a part of the platinum group metal into a platinum group metal oxide can be formed on the surface of the base material.

In the transparent conductive film of the present invention, the transparent conductive film is used as a transparent conductive layer, and one or more transparent thin films having a refractive index different from the refractive index of the transparent conductive layer are provided on the upper layer and / or the lower layer. It is preferably provided. Thereby, external light reflection at the interface of the transparent conductive film can be removed or reduced.

This transparent thin film is expected not only to prevent interfacial reflection in a multilayer thin film, but also to protect the surface from external force when used as a display surface of a display device.
It is preferable to provide a transparent thin film having a practically sufficient strength on the transparent conductive layer.

Suitable transparent thin film materials include silicon,
Examples thereof include aluminum, zirconium, cerium, titanium, yttrium, zinc, magnesium, indium, tin, antimony, gallium, and other oxides, complex oxides, or nitrides. In particular, the following formula: M (OR) _m R _n (wherein M is Si, Ti or Zr, and R is C ₁
To a C ₄ alkyl group, m is an integer of 1 to 4, and n is 4-m), or a mixture of one or more partial hydrolysates thereof. Transparent thin films are preferred. More specifically, tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ) is used as a material capable of forming a transparent thin film of SiO ₂ having a high surface hardness and a relatively low refractive index. transparency,
It is preferably used from the viewpoint of the bondability with the transparent conductive layer, the film strength and the antireflection performance.

The transparent thin film is formed by a method in which a coating liquid (coating for transparent thin film) containing the above components is uniformly applied to a substrate to form a film, as in the method used to form the transparent conductive film. be able to. For coating, any ordinary thin film coating technique such as spin coating, roll coating, spraying, bar coating, dipping, meniscus coating, and gravure printing can be used. Among them, the spin coating method is a particularly preferable coating method because a thin film having a uniform thickness can be formed in a short time. After coating, the coating film is dried and baked to obtain a transparent thin film.

In general, the interfacial antireflection ability of a multilayer thin film is determined by the refractive index and film thickness of the thin film, and the number of laminated thin films. Therefore, even in the transparent conductive film of the present invention, the number of laminated films is taken into consideration. An effective antireflection effect can be obtained by appropriately designing the thickness of the film and the transparent thin film. In the case of a multilayer film having an antireflection function, when the wavelength of the reflected light to be prevented is λ, if the antireflection film has a two-layer structure, the high refractive index layer and the low refractive index layer are respectively λ from the base material side. /
Reflection can be effectively prevented by setting the optical film thickness to 4, λ / 4, or λ / 2, λ / 4. In the case of a three-layered antireflection film, λ / 4 and λ / in the order of the medium refractive index layer, the high refractive index layer and the low refractive index layer from the substrate side.
It is effective to set the optical film thickness to 2, λ / 4.

In particular, in consideration of ease of production and economy, a SiO ₂ film (refractive index 1.46) having a relatively low refractive index and a hard coat property is formed on the transparent conductive layer.
Is preferably formed with a film thickness of λ / 4.

In the transparent conductive film of the present invention comprising two or more layers including the transparent conductive layer, the transparent conductive layer and the transparent thin film may be baked sequentially or simultaneously. For example, the transparent conductive film coating material is applied to the display surface of the display device, the transparent thin film coating material is applied to the upper layer thereof, and after drying,
The low-reflection transparent conductive film may be formed by simultaneously baking the transparent conductive layer and the transparent thin film by baking at a temperature of 0 ° C to 1000 ° C.

A transparent thin film having irregularities is preferably provided on the outermost layer of the transparent conductive film. The transparent thin film having the irregularities has an effect of scattering the surface reflected light of the transparent conductive film and giving an excellent antiglare property to the display surface.

At least one of the transparent conductive films of the present invention
The layer may contain a coloring material. This coloring material is used for improving the contrast of a transmitted image and adjusting the colors of transmitted light and reflected light. As this coloring material,
For example, monoazo pigment, quinacridone, iron oxide yellow, disazo pigment, phthalocyanine green, phthalocyanine blue, cyanine blue,
Flavanslon Yellow, Gianthra Quinolyl Red, Indanthrone Blue, Thioindigo Bordeaux, Perinone Orange, Perylene Scarlet, Perylene Red 17
8, perylene maroon, dioxazine violet, isoindoline yellow, nickel nitroso yellow, madder lake, copper azomethine yellow, aniline black, alkali blue, zinc white, titanium oxide, rouge, chromium oxide,
Iron black, titanium yellow, cobalt blue, cerulean blue, cobalt green, alumina white, viridian, cadmium yellow, cadmium red, vermilion, lithopone, yellow lead, molybdate orange, zinc chromate, calcium sulfate, barium sulfate, calcium carbonate, lead. Organic and inorganic pigments such as white, ultramarine, manganese violet, cobalt violet, emerald green, navy blue, carbon black, and azo dyes, anthraquinone dyes, indigoid dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, quinoline dyes, nitro. Examples thereof include dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes and perinone dyes. These colorants can be used alone or in combination of two or more kinds.

The type and amount of the coloring material to be used should be appropriately selected according to the optical film characteristics of the corresponding transparent conductive film. The absorbance A of the transparent thin film is generally represented by the following formula. A = log ₁₀ (I ₀ / I) = εCD In the formula, I ₀ ; incident light, I; transmitted light, C; color density, D;
Light distance, ε; molar extinction coefficient.

In the transparent conductive film of the present invention, a coloring material having a molar absorption coefficient of ε> 10 is generally used. Further, the blending amount of the colorant varies depending on the molar extinction coefficient of the colorant used, but generally, the absorbance A of the laminated film and the single layer film containing the colorant is within the range of 0.0004 to 3 abs. The amount is preferably such that If these conditions are not satisfied, the transparency and / or the antireflection effect will decrease. When the above-mentioned coloring material is compounded in the transparent conductive layer, the compounding amount thereof is 20% by weight or less, particularly 10% by mass relative to the metal content.
It is preferable to set the content to be not more than weight%. When it exceeds 10% by weight, a decrease in conductivity is recognized, and when it exceeds 20% by weight,
This will interfere with the electromagnetic wave shielding effect.

In the display device of the present invention, any one of the transparent conductive films described above is formed on the display surface. In this display device, since the display surface is prevented from being charged, dust or the like does not adhere to the image display surface, electromagnetic waves are blocked and various electromagnetic interference is prevented, and the image is excellent in light transmission. It is bright, the hue of the transmitted image is natural, the film thickness is uniform, the appearance of the display surface is good, the scratch resistance is good, and the salt water resistance is high, so it is exposed to salt fog. However, it has high durability. If the transparent thin film and / or the transparent thin film having irregularities is formed in addition to the transparent conductive layer, an antireflection effect and / or an antiglare effect against external light can be obtained.

[0028]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. The following stock solutions were prepared as common stock solutions for Examples and Comparative Examples. (Aqueous sol of ruthenium) An aqueous solution containing 0.15 mmol / l of ruthenium chloride and an aqueous solution of 0.024 mmol / l of sodium borohydride were mixed, and the obtained colloidal dispersion was concentrated to give 0.198 An aqueous sol containing mol / l of ruthenium fine particles was obtained. The average particle diameter of the ruthenium fine particles was 20 nm. (Silver aqueous sol) sodium citrate dihydrate (14
g), an aqueous solution (6) in which ferrous sulfate (7.5 g) is dissolved.
0g) was kept at 5 ° C, and silver nitrate (2.5g)
An aqueous solution (25 g) in which g) was dissolved was added to obtain a reddish brown silver sol. This silver sol was washed with water by centrifugation to remove impurity ions, and then pure water was added to obtain 0.185 mol / l.
An aqueous sol containing silver fine particles was obtained. The average particle size of the silver fine particles was 10 nm. (Transparent thin film paint A) Tetraethoxysilane (0.8g)
And 0.1N hydrochloric acid (0.8g) and ethyl alcohol (9
8.4 g) was mixed to form a uniform solution.

(Example 1) Preparation of transparent conductive film paint : Ruthenium aqueous sol 40 g Isopropyl alcohol 10 g Ethyl alcohol 50 g The above components were mixed, and the resulting mixture was mixed with an ultrasonic disperser (“SONIFIER manufactured by BRANSON ULTRASONICS”). 45
0 ") for dispersion to prepare a transparent conductive film paint.

Film formation : The above-mentioned transparent conductive film paint is applied on the display surface of a cathode ray tube by using a spin coater, and after drying, the above-mentioned transparent thin film paint A is applied on this applied surface by using a spin coater in the same manner. , Put this cathode ray tube in the dryer,
A cathode ray tube of Example 1 having an antireflection and high conductive film was prepared by forming a low reflective transparent conductive film by baking at 450 ° C. for 1 hour.

(Example 2) Preparation of transparent conductive film paint : Ruthenium aqueous sol 40 g Isopropyl alcohol 10 g Ethyl alcohol 50 g The above components were mixed and treated in the same manner as in Example 1 to prepare a transparent conductive film paint.

Film formation : A cathode ray tube of Example 2 having an antireflection and high conductive film was prepared by using the above-mentioned transparent conductive film coating material and treating in the same manner as in Example 1 except that the baking temperature was 600 ° C. did.

(Comparative Example 1)Preparation of transparent conductive film paint : Ruthenium aqueous sol 40g Isopropyl alcohol 10g Ethyl alcohol 50g The above components were mixed and treated in the same manner as in Example 1 to give a transparent conductive material.
An electrolytic coating was prepared. Deposition : Using the above transparent conductive film paint, the baking temperature is 15
The same treatment as in Example 1 was carried out except that the temperature was 0 ° C. to prevent reflection.
A cathode ray tube of Comparative Example 1 having a high conductive film was prepared.

(Comparative Example 2)Preparation of transparent conductive film paint : Silver aqueous sol 40g Isopropyl alcohol 10g Ethyl alcohol 50g The above components were mixed and treated in the same manner as in Example 1 to give a transparent conductive material.
An electrolytic coating was prepared. Deposition : Same as Comparative Example 1 using the above transparent conductive film paint
Cathode ray of Comparative Example 2 which has been treated to have antireflection and a high conductive film
Created a tube.

(Evaluation measurement) The performance of the low-reflection transparent conductive film formed on the cathode ray tube was measured by the following device or method,
The appearance was visually evaluated. X-ray diffraction analysis: "PW1710" manufactured by Philips Surface resistance: "Loresta AP" manufactured by Mitsubishi Petrochemicals (4-terminal method) Electromagnetic wave shielding property: Calculated by the above formula 1 based on 0.5 MHz Salt water resistance: After 3 days immersion in salt water 0.5 MHz electromagnetic wave shielding scratch test: Under a load of 1 kg, the metal surface of the mechanical pencil was rubbed on the film surface to visually evaluate the degree of scratches. ○: No scratch △: Slightly scratched ×: Scratched transmittance: Tokyo Denshoku “Automatic Haze Meter H
III DP ”Haze:“ Automatic Haze meter HII ”made by Tokyo Denshoku Co., Ltd.
I DP "Transmittance difference: The difference between the maximum transmittance and the minimum transmittance in the visible light region was obtained using a Hitachi U-3500 type self-recording spectrophotometer. (The smaller the maximum-minimum transmittance difference in the visible light region, the flatter the transmittance becomes, and the clearer the hue of the transmitted image becomes. In particular, at 10% or less, the color of the transmitted image becomes closer to black, and a higher level of sharpness is obtained. Luminous reflectance: EG & G GAMMAS CIENTIFIC “MODEL C-11” Reflective color: Minolta Camera “CR-300” (using the CIE color system, white in the CIE chromaticity diagram) Point (x =
The distance of the deviation from 0.3137, y = 0.3198) was expressed as √ (Δx ² + Δy ² ) using Δx and Δy. As a result, the closer the value of √ (Δx ² + Δy ² ) is to “0”, the closer the reflected color is to white, that is, the closer to natural light that is gentle to the eyes. ) Visibility: Comprehensive evaluation including low reflection performance, reflected color, and transmitted color ○; Good ○ △; Fair ○ △; Fair △ ×; Poor Bad ×; 1 and Table 2 shows the optical test results.

[0036]

[Table 1]

[Table 2]

From the results shown in Table 1, the cathode ray tubes of Examples 1 and 2 which were coated with a coating material containing ruthenium fine particles according to the present invention and baked at 450 ° C. or 600 ° C. showed a transparent conductivity as a result of X-ray diffraction analysis. The presence of ruthenium oxide was confirmed in the film, and in Comparative Example 1 where the firing temperature was 150 ° C., the presence of ruthenium oxide was not observed. Comparing this Example 1 and Example 2 with Comparative Example 1, it can be seen that there is no great difference in the surface resistance in the physicochemical properties (Table 1), and the electromagnetic wave shielding properties, salt water resistance and scratch resistance are greatly improved. . As for the optical characteristics (Table 2), the luminous reflectance was reduced and the visibility was excellent, the reflected color was close to the white point, and the transmitted image was improved to look natural. As a total of these optical characteristics, the visibility evaluations of Example 1 and Example 2 were clearly superior to Comparative Example 1. In Comparative Example 2, silver was used as the conductive material, but it was judged to be poor in terms of visibility because not only the salt water resistance was poor and the durability was poor, but also the luminous reflectance was large and the deviation of the reflected color was large.

[0038]

The transparent conductive film of the present invention has an average particle size of 50.
It is formed by applying a coating material containing at least platinum group metal fine particles having a particle size of nm or less, drying it, and then baking it at a firing temperature in the range of 300 ° C to 1000 ° C. Since it has a transparent conductive layer formed by conversion, it has an excellent antistatic effect and electromagnetic wave shielding effect, and has high salt water resistance and scratch resistance.
Further, the display device having this transparent conductive film has a highly transparent display surface, and the hue of the transmitted image is natural and clear. If the transparent conductive layer contains at least ruthenium, it can be easily converted into RuO ₂ at the above-mentioned baking temperature, and the salt water resistance, chemical stability, and scratch resistance are further improved while being relatively inexpensive. There is also an advantage that the transmission image becomes more natural in terms of hue. If one or more transparent thin films having a refractive index different from the refractive index of the transparent conductive layer are provided on the upper layer and / or the lower layer of the transparent conductive layer, a low reflective transparent conductive film can be obtained. Since the display device of the present invention is one in which the transparent conductive film is formed on the display surface, it has excellent antistatic effect and electromagnetic wave shielding effect, good salt water resistance and durability, High scratch resistance,
The display surface has high transparency, and the hue of the transmitted image is natural and clear, which makes the display device highly practical.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09F 9/00 309 G09F 9/00 309A 313 313 H01J 29/88 H01J 29/88 29/89 29/89 ( 72) Inventor Kazunori Mori 28-6, Rokubancho, Chiyoda-ku, Tokyo Sumitomo Osaka Cement Co., Ltd. F term (reference) 4J038 AA011 HA066 HA146 HA216 NA19 NA20 PA19 PB08 5C032 AA02 DD02 DE01 DF01 DF03 DG01 DG02 DG04 EE03 EE08 EF01 EF02 EF05 5G307 FA01 FB01 FB02 FC02 FC09 5G435 AA02 AA04 AA09 AA14 BB02 BB06 GG32 GG33 HH02 HH03 HH12 HH18 HH20 KK07

Claims (8)

[Claims] 1. A coating material containing at least platinum group metal fine particles having an average particle diameter of 50 nm or less is applied and dried, and then 300
A transparent conductive film having a transparent conductive layer formed by baking at a baking temperature in the range of 100 to 1000 ° C. and having at least a part of the platinum group metal converted to a platinum group metal oxide. 2. The transparent conductive film according to claim 1, wherein the transparent conductive layer contains platinum group metal and platinum group metal oxide in an amount of 10 wt% or more in total. 3. The transparent conductive film according to claim 1, wherein the platinum group metal is at least ruthenium. 4. The transparent conductive film according to claim 1, wherein the platinum group metal oxide is at least ruthenium oxide. 5. The transparent thin film having one or more transparent thin films having a refractive index different from that of the transparent conductive layer is provided on the upper layer and / or the lower layer of the transparent conductive layer. Transparent conductive film. 6. The transparent conductive film according to claim 1, wherein a transparent thin film having irregularities is provided on the outermost layer of the transparent conductive film. 7. The transparent conductive film according to claim 1, wherein at least one layer of the transparent conductive film contains a coloring material. 8. A display device, wherein the transparent conductive film according to any one of claims 1 to 7 is formed on a display surface.