JPH1125759A - Transparent conductive film and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase transparency, enhance electromagnetic wave shielding effect and a charge preventing effect, achieve a natural hue of a transparent image picture with high degree of clearness and improve salt water resistance and scratch strength by applying a coating containing at least platinum-group metallic particles having an average particle diameter of a specific value or lower, and including a specific weight per percent of the platinum metal to a screen of a display, so as to form a transparent conductive film. SOLUTION: A solution having platinum-group metallic particles dispersed in a colloidal state is applied to the screen of a display, thereby forming a transparent conductive film having a uniform thickness. In this case, the particles of platinum-group metal such as ruthenium, palladium, platinum, rhodium, iridium, osmium or the like is used as the metallic particles. The transparent conductive film containing 10 wt.% or more of the platinum metal is formed on the screen with the application of a coating, containing at least the platinum- group metallic particles having an average particle diameter of 50 nm or less. Inclusion of silica particles enhances the film strength. Lamination of one or more transparent conductive films, each having a different refractive index can yield low reflection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an excellent antistatic effect and an excellent electromagnetic wave shielding effect particularly when used on a display surface of a cathode ray tube, a plasma display or the like, and has a natural hue of a transmitted image, a salt water resistance and an acid resistance. TECHNICAL FIELD The present invention relates to a transparent conductive film having excellent durability such as chemical resistance and ultraviolet light resistance, and a display device having the transparent conductive film formed on a display surface.

[0002]

2. Description of the Related Art At present, a cathode ray tube used as a TV cathode ray tube or a computer display projects characters and images on a display surface by projecting an electron beam on a phosphor screen emitting red, green and blue light. Therefore, there is a fear that dust adheres to the display surface due to static electricity generated on the display surface to lower visibility, and that the environment is affected by radiating electromagnetic waves. Recently, it has been pointed out that a plasma display, which is being applied to a wall-mounted television or the like, may generate static electricity or emit electromagnetic waves.

In order to solve these problems, conventionally, a coating liquid in which fine particles such as silver and gold are dispersed in a liquid is applied to a display surface of a display device and dried, or a sputtering method or a vapor deposition method is used. Thus, a conductive transparent metal thin film is formed, and a transparent thin film having a different refractive index from that of the transparent metal thin film is laminated on the upper and / or lower layers of the transparent metal thin film so as to shield electromagnetic waves, prevent charging, and prevent reflection. .

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

[0005]

However, in these methods, although an electromagnetic wave shielding effect can be expected, absorption occurs at a specific wavelength of the transmitted light depending on the light transmission spectrum of the metal, and the conductive film is colored, and The problem that the color of the image changes unnaturally, the problem that the film surface is easily scratched by a scratch strength test in which the film surface is rubbed with a metal piece, and the surface resistance of the conductive film increases when immersed in salt water for 3 days or more. However, since the electromagnetic wave shielding effect is reduced, the problem that attention must be paid to use in a place susceptible to salt fog, such as a seashore, has not been solved. The present invention has been made in order to solve the above-described problems, and therefore, the object thereof is to have high transparency and excellent electromagnetic wave shielding effect and antistatic effect,
Provided is a transparent conductive film in which the hue of a transmitted image is natural, excellent in durability represented by salt water resistance, and further improved in scratch strength, and a display device in which the transparent conductive film is formed on a display surface. It is in.

[0006]

According to the present invention, in order to solve the above-mentioned problems, the present invention is characterized in that the average particle size is 50 nm.
Provided is a transparent conductive film having a transparent conductive layer formed by applying the following paint containing at least platinum group metal fine particles and containing 10% by weight or more of a platinum group metal. In the above, it is preferable that the platinum group metal is at least ruthenium. Alternatively, the platinum group metal is preferably at least palladium. In the above, the transparent conductive layer is formed by applying a paint containing silica fine particles having an average particle diameter of 100 nm or less with respect to the platinum group metal fine particles in a range of 1% by weight to 60% by weight. Is preferred. In the above, the upper layer of the transparent conductive layer and / or
Alternatively, it is preferable that one or more transparent thin films having a refractive index different from that of the transparent conductive layer are provided in the lower layer. It is preferable that a transparent thin film having irregularities is provided on the outermost layer of the transparent conductive film. It is preferable that at least one layer of the transparent conductive film contains a coloring material. The present invention also relates to claim 8,
There is provided a display device in which any of the above transparent conductive films is formed on a display surface.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. The present inventors have conducted intensive studies on a transparent conductive film formed by applying a paint containing metal fine particles to impart an excellent antireflection effect and an electromagnetic wave shielding effect to the display surface of the display device, The use of platinum group metals such as ruthenium, palladium, platinum, rhodium, iridium, and osmium as metal fine particles is extremely important in terms of naturalness of the hue of transmission images, chemical stability represented by salt water resistance, and economic efficiency. The present invention has been found to be effective. These platinum group metal fine particles
A transparent conductive film having a uniform thickness can be easily formed by applying a colloidal aqueous liquid to a display surface of a display device.

According to the present invention, there is provided a transparent conductive film, which is obtained by applying a coating material containing at least the platinum group metal fine particles having an average particle size of 50 nm or less and contains a platinum group metal of 10% by weight or more, on a display surface. The display device of the present invention has an excellent antistatic effect and electromagnetic wave shielding effect, which are the objects of the present invention, and has little absorption at a specific wavelength of visible light, so that there is no disturbance in hue given to a transmitted image, and also against salt water. It was found to have a practically sufficient level of resistance.

A coating material containing the above-mentioned platinum group metal fine particles having an average particle size of 50 nm or less is applied on a substrate, dried and then dried at 150 ° C.
When the film is formed by baking at a temperature of about 250 ° C., the metal particles fuse with each other and have at least partly, despite the low baking temperature, because the average particle diameter of the metal fine particles is 50 nm or less. A continuous metal thin film is formed. For this reason, in the transparent conductive film of the present invention, much higher conductivity than that obtained by simply contacting the metal fine particles is obtained, and as a result, the antistatic effect and the electromagnetic wave shielding effect are excellent. Instead, a transparent conductive film having high transparency can be obtained.

The conductive property of the transparent conductive film required to exhibit an electromagnetic wave shielding effect in addition to the antistatic function is represented by the following equation (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 the conductive film, f (MHz) Electromagnetic wave frequency, and t (cm); thickness of conductive film. Here, the thickness t is 1 μm from the viewpoint of light transmittance.
(1 × 10 ⁻⁴ cm) or less, the electromagnetic wave shielding effect S can be approximately expressed by the following expression 2 if the term including the film thickness t is ignored in the expression 1. S = 50 + 10log (1 / ρf) Equation 2

Here, as the value of S (dB) increases, the electromagnetic wave shielding effect increases. Generally, the electromagnetic wave shielding effect is S>
If it is 30 dB, it is considered to be effective, and if S> 60 dB, it is considered to be excellent. In addition, since the frequency of the electromagnetic wave to be regulated is generally in the range of 10 kHz to 1000 MHz, the conductivity of the transparent conductive film needs to have a volume resistivity (ρ) of 10 ³ Ω-cm or less. That is, the lower the volume specific resistance value (ρ) of the transparent conductive film, the more effectively electromagnetic waves of a wider range of frequencies can be shielded. In order to satisfy this condition, the transparent conductive film must contain the platinum group metal in an amount of 10% by weight or more. When the content of the platinum group metal is less than 10% by weight, the conductivity is lowered, and it is difficult to obtain a substantial electromagnetic wave shielding effect.

After satisfying the above conditions, the thickness of the transparent conductive film should be 200 in consideration of transparency and antireflection properties.
nm or less is preferable. The obtained transparent conductive film may be a smooth film or a film having an uneven network structure.

The platinum group metal used for the transparent conductive film of the present invention is particularly preferably ruthenium or palladium. Among the platinum group metals, ruthenium and palladium are relatively inexpensive, have high chemical stability and sufficient salt water resistance for practical use, and also have a hue of 400 nm to 700 nm.
Since there is no light absorption peak of a specific wavelength in the visible light region of nm, the transmitted image is not unnaturally colored, and the metal fine particles are easily fused at the time of film formation, so that the conductivity is further improved while maintaining high transparency. Can be improved.

The transparent conductive film of the present invention may contain other metals such as silver, gold, copper, nickel and the like in addition to the above platinum group metals. In particular, silver is relatively easily and inexpensively available as a colloidal dispersion, and has high conductivity and excellent antistatic properties and electromagnetic wave shielding properties. It is effective when you want to lower. Silver is not durable due to poor salt water resistance when used alone as a conductive material of the transparent conductive film, but when used with a platinum group metal, it alloys at the baking temperature during film formation,
It becomes a chemically stable conductive material.

When a metal other than the platinum group metal is used together with the platinum group metal, it may be used as a coating containing both platinum group metal fine particles and the above-mentioned metal fine particles, or separately from a coating containing platinum group metal fine particles. A transparent conductive film can be formed by applying a coating material containing the metal fine particles having an average particle diameter of 50 nm or less to the base material.

In addition to the above-mentioned platinum group metal fine particles, a coating material containing silica fine particles having an average particle diameter of 100 nm or less in the range of 1% by weight to 60% by weight based on the platinum group metal fine particles is obtained. The film strength of the transparent conductive film thus improved is remarkably improved, and a transparent conductive film having high scratch strength can be obtained. When the transparent conductive film contains silica fine particles, when one or more transparent thin films having a refractive index different from the refractive index of the transparent conductive film are provided in an upper layer and / or a lower layer thereof, a silica-based transparent thin film is used. Since the compatibility with the binder component is good, there is also an advantage that the adhesion between both films is improved, and the scratch strength is further improved. Silica fine particles, from the viewpoint of both improving the film strength and conductivity,
It is preferable that the content is contained in the range of 20% by weight to 40% by weight based on the platinum group metal fine particles.

In the transparent conductive film of the present invention, in addition to the above-mentioned components, other components such as silicon, aluminum, zirconium, cerium, titanium, yttrium, zinc, and the like may be used for the purpose of improving the film strength and conductivity. magnesium,
Oxides such as indium, tin, antimony and gallium,
Composite oxides or nitrides, especially oxides of indium or tin, inorganic fine particles mainly composed of composite oxides or nitrides, polyester resins, acrylic resins, epoxy resins, melamine resins, urethane resins, butyral resins , Organic synthetic resins such as ultraviolet curable resins, silicon, titanium,
It may contain a hydrolyzate of a metal alkoxide such as zirconium, or an organic / inorganic binder component such as a silicone monomer or silicone oligomer.

The above-mentioned paint containing at least platinum group metal fine particles can be applied to a substrate by spin coating, roll coating, spraying, bar coating, dipping, meniscus coating, gravure printing, etc. Any conventional thin film coating technique can be used. Of these, spin coating is a particularly preferred coating method because a thin film having a uniform thickness can be formed in a short time. After the application, the coating film is dried and baked at 150 ° C. to 250 ° C. to form a transparent conductive layer on the surface of the substrate.

The transparent conductive film of the present invention is preferably provided with at least one transparent thin film having a refractive index different from that of the transparent conductive layer in the upper and / or lower layer of the transparent conductive layer. . Thus, external light reflection at the interface of the transparent conductive film can be removed or reduced.

The transparent thin film is expected to not only prevent interfacial reflection in the multilayer thin film, but also to protect the surface from external force when used for the display surface of a display device. Preferably, a thin film is provided on the transparent conductive layer.

Materials for forming the transparent thin film include, for example, thermoplastic, thermosetting, or photo and electron beam curable resins such as polyester resin, acrylic resin, epoxy resin, and butyral resin; silicon, aluminum, titanium, zirconium, etc. Hydrolyzate of metal alkoxide; silicone monomer or silicone oligomer alone,
Alternatively, they are used in combination.

A particularly preferred transparent thin film is a SiO ₂ thin film having a high surface hardness and a relatively low refractive index. As an example of a material that can form this SiO ₂ thin film, for example, the following formula: M (OR) _m R _n (where M is Si, R is a C ₁ -C ₄ alkyl group, and m is 1 And n is an integer of 0 to 3, and m + n is 4.) or a mixture of one or more partial hydrolysates thereof. As an example of this compound, particularly, tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ) is suitably used from the viewpoints of thin film formation, transparency, bonding with a transparent conductive layer, film strength, and antireflection performance. .

The above-mentioned transparent thin film can be made of various resins, metal oxides,
It may contain a composite oxide, a nitride, or the like, or a precursor capable of producing them by baking.

The formation of the transparent thin film can be carried out by a method of uniformly applying a coating liquid (paint for a transparent thin film) containing the above-mentioned components and forming a film in the same manner as the method used for forming the transparent conductive film. . For coating, any of ordinary thin film coating techniques such as spin coating, roll coating, spraying, bar coating, dipping, meniscus coating, and gravure printing can be used. Of these, spin coating is a particularly preferred 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 at 150 ° C. to 250 ° C. to obtain a transparent thin film.

In general, the antireflection ability at the interface of a multilayer thin film is determined by the refractive index and thickness of the thin film and the number of laminated thin films. By appropriately designing the thickness of the film and the transparent thin film, an effective antireflection effect can be obtained. In a multilayer film having antireflection ability, when the wavelength of 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 substrate side. /
By setting the optical film thickness to 4, λ / 4, or λ / 2, λ / 4, reflection can be effectively prevented. In the case of a three-layered antireflection film, λ / 4, λ /
An optical film thickness of 2, λ / 4 is effective.

In particular, considering the ease of manufacture and economy, an SiO ₂ film (refractive index: 1.46) having a relatively low refractive index and having a hard coat property is formed on the transparent conductive layer at λ / 4. It is preferable that the film is formed to have a film thickness.

In the transparent conductive film of the present invention comprising two or more layers including a transparent conductive layer, the baking of the transparent conductive layer and the transparent thin film may be performed sequentially or simultaneously. For example, a paint for a transparent conductive film is applied to the display surface of a display device, a paint for a transparent thin film is applied thereon, and after drying, 15
By baking at a temperature of 0 ° C to 250 ° C,
The transparent conductive layer and the transparent thin film may be simultaneously formed to form a low-reflection transparent conductive film.

It is preferable to provide a transparent thin film having irregularities on the outermost layer of the transparent conductive film. The transparent thin film having the irregularities scatters light reflected on the surface of the transparent conductive film, and has an effect of giving excellent antiglare properties 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 color 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,
Flavanthrone yellow, dianthraquinolyl 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, red iron oxide, chrome oxide,
Iron black, titanium yellow, cobalt blue, cerulean blue, cobalt green, alumina white, viridian, cadmium yellow, cadmium red, vermilion, lithopone, graphite, 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, and carbon black, as well as azo dyes, anthraquinone dyes, indigoid dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, quinoline dyes, and nitro dyes Dyes such as dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes and perinone dyes can be mentioned. These coloring materials can be used alone or in combination of two or more.

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 equation. A = log ₁₀ (I ₀ / I) = εCD where I _{0 is} incident light, I is transmitted light, C is color density, D is light distance, and ε is molar extinction coefficient.

In the transparent conductive film of the present invention, a coloring material having a molar absorption coefficient ε> 10 is generally used. The amount of the coloring material varies depending on the molar extinction coefficient of the coloring material used. Generally, the absorbance A of the laminated film and the single-layer film containing the coloring material is in the range of 0.0004 to 3 abs. Preferably, the amount is such that If these conditions are not satisfied, the transparency and / or the antireflection effect will decrease. When the coloring material is blended with the transparent conductive layer, the blending amount is 20% by weight or less, particularly 10
% By weight or less. If it exceeds 10% by weight, a decrease in conductivity is observed.
This will hinder 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 a display surface. This display device prevents the charging of the display surface, so that dust and the like do not adhere to the image display surface, shields electromagnetic waves, prevents various types of electromagnetic wave interference, and is excellent in light transmissivity. It is bright, the hue of the transmitted image is natural, the film thickness is uniform, the appearance of the display surface is good, and the salt water resistance is high, so the durability is high even in an environment exposed to salt fog. If the transparent thin film and / or the transparent thin film having irregularities are formed in addition to the transparent conductive layer, an antireflection effect and / or an antiglare effect for external light can be obtained.

[0033]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. The following were prepared as stock solutions common to Examples and Comparative Examples. (Ruthenium aqueous sol) An aqueous solution containing 0.15 mmol / l ruthenium chloride and a 0.024 mmol / l aqueous sodium borohydride solution were mixed, and the obtained colloidal dispersion was concentrated to 0.198 mmol / l. An aqueous sol containing mol / l of ruthenium fine particles was obtained. The average particle size of the ruthenium fine particles was 20 nm. (Palladium aqueous sol) An aqueous solution containing 0.15 mmol / l palladium chloride and a 0.024 mmol / l aqueous sodium borohydride solution were mixed, and the obtained colloidal dispersion was concentrated to 0.189 mmol / l. An aqueous sol containing mol / l palladium fine particles was obtained. The average particle size of the palladium fine particles was 10 nm. (Silver aqueous sol) sodium citrate dihydrate (14
g) and an aqueous solution (6 g) in which ferrous sulfate (7.5 g) is dissolved.
0 g) was kept at 5 ° C., and silver nitrate (2.5 g) was added thereto.
An aqueous solution (25 g) in which g) was dissolved was added to obtain a red-brown silver sol. The silver sol was washed with water by centrifugation to remove impurity ions, and then added with pure water 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. (Colloidal silica) "Silica Doll 30" manufactured by Nippon Chemical Industry Co., Ltd. (Transparent thin film coating A) Tetraethoxysilane (0.8 g)
And 0.1 N hydrochloric acid (0.8 g) and ethyl alcohol (9
8.4 g) to obtain a uniform solution. (Uneven transparent thin film paint B) tetraethoxysilane (3.0
g), 0.1 N hydrochloric acid (10 g) and ethyl alcohol (8
7.0 g) to obtain a uniform solution.

(Example 1) Preparation of transparent conductive film paint : Ruthenium aqueous sol 40 g Isopropyl alcohol 10 g Colloidal silica 0.8 g Ethyl alcohol 49.2 g The above components were mixed, and the resulting mixture was mixed with an ultrasonic disperser ( "Sonifire 45" manufactured by BRANSON ULTRASONICS
0 ") to prepare a transparent conductive film paint. The SiO ₂ / Ru weight ratio in the paint was 30/100.

Film formation : The above-mentioned transparent conductive film paint A is applied to the display surface of a cathode ray tube using a spin coater, and after drying, the above-mentioned transparent thin film paint A is applied to the display surface of the cathode ray tube similarly using a spin coater. , Put this CRT in the dryer,
By baking at 150 ° C. for 1 hour to form a low-reflection transparent conductive film, the cathode ray tube of Example 1 having an antireflection and high-conductive film was prepared.

(Example 2) Preparation of transparent conductive film paint : Ruthenium aqueous sol 40 g Isopropyl alcohol 10 g Colloidal silica 0.8 g Ethyl alcohol 49.2 g The above components were mixed and treated in the same manner as in Example 1 to obtain a transparent conductive film. A membrane coating was prepared. The SiO ₂ / Ru weight ratio in the paint was 30/100.

Film formation : The above-mentioned transparent conductive film paint is applied to the display surface of a cathode ray tube using a spin coater, and after drying, the above-mentioned transparent thin film paint A is applied to this display surface similarly using a spin coater. Further, in order to form a transparent uneven layer, the above-mentioned uneven transparent thin film paint B is sprayed and laminated by a spray, and the cathode ray tube is placed in a drier and baked at 150 ° C. for 1 hour to obtain a transparent outermost layer. 3 with uneven layer formed
By forming a transparent conductive film having a layer structure, a cathode ray tube of Example 2 having an antiglare property, antireflection, and a high conductive film was prepared.

(Example 3) Preparation of transparent conductive film paint : aqueous palladium sol 40 g isopropyl alcohol 10 g colloidal silica 0.8 g ethyl alcohol 49.2 g The above components were mixed and treated in the same manner as in Example 1 to obtain a transparent conductive film. A membrane coating was prepared. The SiO ₂ / Pd weight ratio in the paint was 30/100. Film formation : Using the above-mentioned transparent conductive film paint, the same treatment as in Example 1 was carried out to prepare a cathode ray tube of Example 3 having an antireflection and high conductive film.

Example 4 Preparation of Transparent Conductive Paint : Ruthenium Aqueous Sol 38 g Silver Aqueous Sol 2 g Isopropyl Alcohol 10 g Colloidal Silica 0.8 g Ethyl Alcohol 49.2 g The above components were mixed and treated in the same manner as in Example 1. Thus, a transparent conductive film paint was prepared. SiO ₂ / (Ru + A) in paint
g) The weight ratio was 30/100. Film formation : Using the above-mentioned transparent conductive film paint, the same treatment as in Example 1 was carried out to prepare a cathode ray tube of Example 4 having an antireflection and high conductive film.

(Embodiment 5)Preparation of transparent conductive film paint : Aqueous ruthenium sol 40 g isopropyl alcohol 10 g ethyl alcohol 50 g
An electrocoat was prepared. Film formation : Using the above transparent conductive film paint, as in Example 1.
Cathode ray of Example 5 having anti-reflection and high conductive film by processing
A tube was created.

(Comparative Example 1)Preparation of transparent conductive film paint : Aqueous silver sol 40 g isopropyl alcohol 10 g ethyl alcohol 50 g
An electrocoat was prepared. Film formation : Using the above transparent conductive film paint, as in Example 1.
Cathode ray of Comparative Example 1 having anti-reflection and high conductive film after treatment
A tube was created.

(Comparative Example 2) Preparation of transparent conductive film paint : silver aqueous sol 40 g colloidal silica 0.8 g isopropyl alcohol 10 g ethyl alcohol 49.2 g The above components were mixed and treated in the same manner as in Example 1 to obtain a transparent conductive film. A membrane coating was prepared. The SiO ₂ / Ag weight ratio in the paint was 30/100. Film formation : Using the above-mentioned transparent conductive film paint, the same treatment as in Example 1 was carried out to prepare a cathode ray tube of Comparative Example 2 having an anti-reflection and high conductive film.

(Comparative Example 3)Preparation of transparent conductive film paint : Antimony-doped tin oxide fine powder 1.5 g (Sumitomo Osaka Cement Co., Ltd., average particle size 0.01 μm) Carbon black 0.3 g (Mitsubishi Chemical Co., Ltd., “MA-100”) Isopropyl alcohol 10 g Butyl cellosolve 10 g Pure water 78. 2g The above components were mixed, treated in the same manner as in Example 1, and
An electrocoat was prepared. Film formation : Using the above transparent conductive film paint, as in Example 1.
Cathode ray of Comparative Example 3 having anti-reflection and high conductive film by processing
A tube was created.

(Evaluation Measurement) The performance of the low-reflection transparent conductive film formed on the cathode ray tube was measured by the following apparatus or method.
The appearance was visually evaluated. Surface resistance: "Loresta AP" (manufactured by Mitsubishi Yuka Co., Ltd.) (4-terminal method) Electromagnetic wave shielding property: Calculated by the above formula 1 based on 0.5 MHz. Under load, the membrane surface was rubbed with the metal part of the tip of a mechanical pencil, and the degree of scratching was visually evaluated. ○: no scratch △: slightly scratched ×: scratched Transmittance: "Automatic Haze Meter HII" manufactured by Tokyo Denshoku
IDP ”Haze:“ Automatic Haze meter HII manufactured by Tokyo Denshoku Co., Ltd.
IDP "Gross: Variable angle gloss meter" MODEL TC-1 "manufactured by Tokyo Denshoku Co., Ltd.
08D "Incident angle 60 ° Transmittance difference: The difference between the maximum transmittance and the minimum transmittance in the visible light region was determined using a" U-3500 "type self-recording spectrophotometer manufactured by Hitachi, Ltd. (The smaller the maximum-minimum transmittance difference in the visible light region, the flatter the transmittance and the sharper the hue of the transmitted image. Particularly, when the difference is 10% or less, the color of the transmitted image approaches black, and the higher the sharpness. Luminous reflectance: "MODEL C-11" manufactured by EG & G GAMMASCIENTIFIC Inc. Reflection color: "CR-300" manufactured by Minolta Camera (CIE colorimetric system, white in CIE chromaticity diagram Point (x =
0.3137, y = 0.3198), and Δ (Δx ² + Δy ² ) using Δx and Δy. Thus, the closer the value of √ (Δx ² + Δy ² ) is to “0”, the whiter the reflection color becomes, that is, the closer to the natural light that is easy on the eyes. ) Visibility: Comprehensive evaluation including low reflection performance, reflection color, and transmission color ○: good ○ △; somewhat good △: acceptable △ ×; somewhat poor ×: poor Among the above evaluation tests, the physicochemical test results are shown. Table 1 shows the optical test results.

[0045]

[Table 1]

[Table 2]

From the results shown in Table 1, the cathode ray tubes of Examples 1 to 5 having a transparent conductive film containing ruthenium or palladium as a platinum group metal according to the present invention have excellent antistatic properties because their surface resistance is sufficiently small. Has an effect and
Since the 5 MHz electromagnetic wave shielding property is sufficiently high, it has an excellent electromagnetic wave shielding effect. High durability against salt water. In Example 4, although silver was contained, an alloy with ruthenium was formed during film formation, and the salt water resistance did not decrease. Example 1
In Example 4, since the transparent conductive layer contains fine silica particles, the scratch strength is also good.

From the results shown in Table 2, the cathode ray tubes of Examples 1 to 5 have a practically sufficient light transmittance, so that the transmitted images are bright. The haze is also at a satisfactory level, and the contrast of the transmitted image is not impaired. In Example 2, since the uneven layer is formed on the outermost layer, the gloss value is low, surface reflection is suppressed, and reflection of external light is reduced.
Because the difference in transmittance due to wavelength is small, it looks black
The hue of the transmitted image is clear. In Examples 1 to 5, the luminous reflectance is low and the visibility is excellent because the transparent thin film for anti-reflection is formed. Since the reflection color is close to the white point, the transmitted image looks natural. The visibility evaluation as a total of these optical characteristics was clearly superior to the comparative example.

On the other hand, Comparative Example 3 using antimony-doped tin oxide as the conductive material is inferior in both antistatic effect and electromagnetic wave shielding effect. In Comparative Examples 1 and 2, since silver was used as the conductive material, the initial antistatic effect and the electromagnetic wave shielding effect were good, but the salt water resistance was low and the durability was not high. In Comparative Examples 1 and 2, the transmittance difference is large due to silver, and the clearness of the transmitted image is insufficient. Further, since the reflected color is also biased, the transmitted image looks unnatural hue. As an overall result, the visibility evaluation of Comparative Examples 1 to 3 was inferior to Examples 1 to 5.

[0049]

The transparent conductive film of the present invention includes a transparent conductive layer formed by applying a paint containing fine particles of platinum group metal, and the transparent conductive layer contains at least 10% by weight of platinum group metal. It has excellent antistatic effect and electromagnetic wave shielding effect, and has high salt water resistance. Further, the display device on which the transparent conductive film is formed has high transparency of the display surface, and the hue of the transmitted image is natural and clear. If the transparent conductive layer contains fine silica particles, a transparent conductive film having high film strength can be obtained. If at least one transparent thin film having a refractive index different from the refractive index of the transparent conductive layer is provided on the upper layer and / or the lower layer of the transparent conductive layer, a transparent conductive film having low reflection can be obtained. In addition, when a transparent thin film having irregularities is provided on the outermost layer, a transparent conductive film with high contrast and high visibility can be obtained by suppressing surface reflection. Since the display device of the present invention is one in which the transparent conductive film is formed on a display surface, it has an excellent antistatic effect and an electromagnetic wave shielding effect, and has good salt water resistance and durability. In addition, the display device has high transparency on the display surface, the hue of the transmitted image is natural and clear, and the display device has high practicality.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09D 7/12 C09D 7/12 Z G02B 1/10 H01B 1/08 H01B 1/08 H01J 11/02 Z H01J 11/02 29 / 28 29/28 G02B 1/10 Z

Claims (8)

[Claims] 1. A transparent conductive film formed by applying a paint containing at least platinum group metal fine particles having an average particle size of 50 nm or less, and having a transparent conductive layer containing 10% by weight or more of a platinum group metal. 2. The transparent conductive film according to claim 1, wherein said platinum group metal is at least ruthenium. 3. The transparent conductive film according to claim 1, wherein said platinum group metal is at least palladium. 4. The transparent conductive layer has an average particle diameter of 100 n.
m or less of silica fine particles with respect to the platinum group metal fine particles.
2. The transparent conductive film according to claim 1, wherein the transparent conductive film is formed by applying a coating material contained in a range of from 60 wt% to 60 wt%. 3. 5. The transparent conductive layer according to claim 1, wherein 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 and / or lower layers 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 an 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 claim 1 is formed on a display surface.