JP3501942B2 - Paint for forming transparent conductive film, transparent conductive film, and display device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive film-forming coating material, a transparent conductive film, and a display device. With the effect, the visible light average transmittance of the film is very high and the hue of the transmitted image is natural,
Moreover, the present invention relates to a transparent conductive film having excellent durability such as salt water resistance, oxidation resistance, and ultraviolet resistance, and a display device having the transparent conductive film formed on a display surface.

[0002]

2. Description of the Related Art Cathode ray tubes currently used as TV cathode ray tubes and computer displays are red,
Characters and images are projected on the display surface by projecting an electron beam on the fluorescent surface that emits green and blue light, so that static electricity generated on this display surface causes dust to adhere and reduces visibility. There is a risk of radiating electromagnetic waves and affecting the environment. In addition, even in plasma displays, which are being applied as wall-mounted televisions recently,
It has been pointed out that the generation of static electricity and electromagnetic radiation are possible.

In order to solve these problems, conventionally, a coating liquid in which fine particles such as silver and gold are uniformly dispersed in a liquid is applied and dried on the display surface of a display device, or by a sputtering method or vapor deposition. A conductive transparent metal thin film is formed by a method, and a transparent layer having a refractive index different from that of the transparent metal thin film is laminated on the upper layer and / or the lower layer of the transparent metal thin film for electromagnetic wave shielding, antistatic, and antireflection. .

For example, in Japanese Unexamined Patent Publication (Kokai) No. 8-77832, a transparent conductive film having an excellent electromagnetic wave shielding effect and an antireflection effect is provided with a conductive layer made of metal fine particles containing at least silver having an average particle size of 2 nm to 200 nm. , A transparent layer having a different refractive index is proposed.

[0005]

However, in these methods, although the electromagnetic wave shielding effect can be expected, absorption occurs in the transmitted light of 400 nm to 500 nm depending on the light transmission spectrum of silver, and the conductive film is colored yellow. However, the problem that the hue of the transmitted image changes unnaturally, the problem that the unevenness of the transmitted color due to the film thickness distribution is conspicuous because the average visible light transmittance of the film is low, and the productivity deteriorates, and the salt fog environment Then, since the surface resistance of the conductive film increases and the electromagnetic wave shielding effect decreases,
Problems such as deterioration of durability were not solved in places such as the coast, which are easily affected by salt fog. The present invention has been made in order to solve the above problems, and therefore an object thereof is that the film has a high average visible light transmittance, an excellent electromagnetic wave shielding effect and an antistatic effect, and the hue of a transmitted image is An object of the present invention is to provide a transparent conductive film which is natural and has excellent durability represented by salt water resistance, 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 the following coating composition for forming a transparent conductive film and transparent conductive film.
An electric film and a display device are provided. That is, the transparency of the present invention
The conductive film-forming coating material contains an aggregate of fine metal particles as a conductive material, and the particle diameter of the aggregate is in the range of 5 nm to 50 nm.
It is characterized by being inside. It is preferable that the metal fine particles include at least gold fine particles. Formation of this transparent conductive film
The coating material is silica fine particles with an average particle size of 100 nm or less.
It is preferable to include. The transparent conductive film of the present invention is characterized by having a conductive layer formed by applying the above-mentioned transparent conductive film-forming coating material . The thickness of the conductive layer is 1
It is preferably in the range of 0 nm to 50 nm. The above
On the upper layer of the conductive layer, or the lower layer, or the upper layer and the lower layer,
It is preferable that at least one transparent layer having a refractive index different from that of the conductive layer is laminated. A transparent layer having irregularities is preferably laminated on the outermost layer of the transparent conductive film. The transparent conductive film has an average visible light transmittance of 80.
% And the surface resistance is preferably 1 × 10 5 Ω / □ or less. The display device of the present invention has the above-mentioned transparency.
A conductive film is formed on the display surface.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to preferred specific examples. FIG. 1 is a partial sectional view of a preferred display device of the present invention. In this display device, a conductive layer 2, a transparent layer 3, and a transparent layer (hereinafter, referred to as “concavo-convex layer”) 4 having irregularities on the outermost layer are sequentially laminated on a display surface 1 of the conductive layer. 2, transparent layer 3, and uneven layer 4
Form the transparent conductive film 5 of the present invention.

The inventors of the present invention have keenly studied a transparent conductive film formed by applying a coating material containing metal fine particles in order to impart an excellent antireflection effect and electromagnetic wave shielding effect to the display surface 1 of a display device. As a result of research, in particular, when the conductive layer 2 is formed by using a coating material containing an aggregate of metal fine particles as a conductive material, it is transparent and has a high conductive performance as compared with the case where the metal fine particles are uniformly dispersed. Membrane 5
The present invention has been arrived at by the finding that the above can be produced.

The present invention will be described in more detail below. As the metal fine particles used for the conductive layer 2, generally,
Fine particles of precious metals such as gold, silver, palladium, ruthenium, platinum, rhodium, iridium and osmium can be effectively used. In particular, when gold fine particles are the main component, the light transmittance and the conductivity are remarkably high, and they are chemically stable. When this aggregate is applied to the display surface 1 of the display device, the brightness of the transmitted image is reduced. It has been found that excellent electromagnetic wave shielding properties and chemical stability represented by salt water resistance can be obtained without impairing the hue and hue, and that the light transmittance is so high that unevenness of the film thickness of the coating film is inconspicuous. . As a result, it has been possible to significantly improve the non-defective rate in the film forming process, which has been particularly problematic up to now, and to improve the economical efficiency.

The transparent layer 2 preferably contains gold as a main component of the metal for the conductive material, but in addition to this, other metals such as silver, copper, platinum, palladium, ruthenium, rhodium, It may include iridium, rhenium, osmium and the like. In particular, silver is relatively easily and cheaply available as a colloidal dispersion liquid, and has high conductivity and excellent antistatic property and electromagnetic wave shielding property, so that the cost of the transparent conductive film can be further improved while maintaining the conductivity. This is effective when you want to lower the price. When silver is used alone as the conductive material of the transparent conductive film, it has poor durability due to poor salt water resistance, but when it is used as a mixture containing gold as the main component, chemical stability increases and practically sufficient durability is obtained. To be

In the coating composition for forming a transparent conductive film of the present invention,
It is particularly important that the metal fine particles are not uniformly dispersed independently but form an aggregate. A conductive layer obtained by applying a transparent conductive film-forming coating material containing an aggregate of metal fine particles (hereinafter, simply referred to as “aggregate”) on a base material and baking it after drying is The contact resistance between the particles in the layer is smaller than that in the case of using the metal particles that are uniformly dispersed independently. As a result, even if the conductive layer 2 is formed as an extremely thin layer of 10 nm to 50 nm, the surface resistance of the obtained transparent conductive film is 1 × 1.
It is less than 0 ⁵ Ω / □ and has an excellent antistatic effect and electromagnetic wave shielding effect, and an average visible light transmittance of 80.
%, The transparency is as high as 10% or more, and the unevenness of the film thickness is not noticeable. This effect is particularly remarkable when the particle size of the aggregate is within the range of 5 nm to 50 nm, more preferably within the range of 20 nm to 40 nm.

There are various methods for forming the above-mentioned aggregates. For example, water-soluble salts such as sodium salt, potassium salt, calcium salt and ammonium salt in the process of producing metal fine particles or in a uniform dispersion liquid of metal fine particles; An acid such as hydrochloric acid, nitric acid, phosphoric acid or acetic acid; an alkali such as caustic soda or ammonia; or a method of adding a water-soluble solvent having a relatively weak polarity, a method of heat treatment, or the like can be applied.

It is obtained by applying a coating material for forming a transparent conductive film containing at least the above-mentioned agglomerates and has a film thickness of 10 nm to 50 nm.
The display device of the present invention in which the transparent conductive film 5 having the conductive layer 2 in the range of nm is formed on the display surface 1 has an average visible light transmittance of the transparent conductive film 5 of 80% or more and Since the absorption at the wavelength is small, the hue of the transmitted image is not impaired, and the excellent antistatic effect and electric field shielding effect, which are the objects of the present invention, are obtained, and practically sufficient resistance to salt water is also provided. In addition, due to its high light transmittance, the unevenness of the film thickness of the coating film becomes inconspicuous.

The conductive layer 2 may contain silica fine particles having an average particle diameter of 100 nm or less within a range of 1% by weight to 60% by weight based on the aggregate, in addition to the above aggregate.
The conductive layer 2 obtained by applying the transparent conductive film-forming coating material containing silica fine particles to form a film has significantly improved film strength,
Scratch strength is improved. In addition, by including fine silica particles in the conductive layer 2, an upper layer or a lower layer is formed.
When at least one transparent layer 3 having a refractive index different from that of the conductive layer is provided in the layer, or in the upper layer and the lower layer, both of the transparent layers 3 have good wettability with the silica-based binder component. It also has the advantage of improving the adhesion of the layer, and can further improve the scratch strength. The silica fine particles are more preferably contained in the range of 20% by weight to 40% by weight based on the aggregate, from the viewpoint of achieving both improved film strength and conductivity.

In the transparent conductive film 5 of the present invention, the conductive layer 2
In addition to the above components, for the purpose of improving the film strength and conductivity, other components such as silicon, aluminum, zirconium, cerium, titanium, yttrium, zinc, if necessary,
Oxides of magnesium, indium, tin, antimony, gallium, etc., complex oxides, or nitrides, especially fine particles of inorganic substances containing indium or tin oxides, complex oxides or nitrides as main components, polyester resin, acrylic Resin, epoxy resin, melamine resin, urethane resin, butyral resin, organic synthetic resin such as UV curable resin, hydrolyzate of metal alkoxide such as silicon, titanium, zirconium,
Alternatively, an organic / inorganic binder component such as a silicone monomer or a silicone oligomer may be included.

To apply the above-mentioned coating material for forming a transparent conductive film containing at least an aggregate of fine metal particles on a substrate, spin coating, roll coating, spray coating, bar coating, dip coating, meniscus coating, gravure coating Any of the usual thin film coating techniques such as can be used. Among them, spin coating 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 at 100 ° C to 1000 ° C to form the conductive layer 2 on the surface of the base material.

Fine metal particles (aggregates) in the conductive layer 2
When determining the content and film thickness of the, it is necessary to consider the requirement of the electromagnetic wave shielding effect. Generally, the conductive performance of the conductive layer required to exert the electromagnetic wave shielding effect in addition to the antistatic effect is represented by the following formula (1) . S = 50 + 10log (1 / ρf) + 1.7t√ (f / ρ) ... in (1) (1), S (dB): electromagnetic shielding effect, ρ (Ω-cm): the volume of the conductive layer 2 resistivity , F (MHz) : electromagnetic wave frequency, t (cm) : film thickness of the conductive layer 2. Here, the film thickness t is 1 μm from the viewpoint of light transmittance.
Since it is about (1 × 10 ⁻⁴ cm) or less and is extremely small, the electromagnetic wave shielding effect S is approximately represented by the following formula (2) if the term including the film thickness t in the formula (1) is ignored. be able to. S = 50 + 10 log (1 / ρf) (2) Here, the larger the value of S (dB), the greater the electromagnetic wave shielding effect.

Generally, the electromagnetic wave shielding effect is effective if S> 30 dB, and is excellent if S> 60 dB. In addition, the frequency of electromagnetic waves to be regulated is generally 10
Since it is within the range of kHz to 1000MHz, the transparent conductive film 5
For the conductivity of, the volume resistivity (ρ) of 10 ³ Ω-cm or less is required. That is, if the volume resistivity (ρ) of the transparent conductive film 5 is as low as possible, electromagnetic waves in a wider range of frequencies can be effectively shielded. In order to satisfy this condition, the film thickness of the conductive layer 2 in the transparent conductive film 5 is 10
It is preferable that the thickness is not less than nm and that the gold is contained in an amount of 10% by weight or more. When the thickness of the conductive layer 2 is less than 10 nm or the gold 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 film thickness of the conductive layer 2 in the transparent conductive film 5 is
Considering transparency, the thickness is preferably 50 nm or less.

In the transparent conductive film 5 of the present invention, it is preferable that at least one transparent layer 3 is laminated on the conductive layer 2 as an upper layer, a lower layer, or an upper layer and a lower layer (the upper layer in FIG. 1). . The transparent layer 3 preferably has a refractive index different from that of the conductive layer 2. This not only protects the conductive layer 2, but also
External light reflection at the interlayer interface of the obtained transparent conductive film 5 can be effectively removed or reduced. Further, the transparent layer 3 is expected to have an effect of not only preventing interfacial reflection in the multilayer thin film but also protecting the surface from external force when it is used as a display surface of a display device, and therefore has a practically sufficient hard coat property. It is more preferable to have

As a material for forming the transparent layer, for example, a thermoplastic resin such as polyester resin, acrylic resin, epoxy resin, butyral resin, thermosetting resin, or photo-electron beam curable resin; silicon, aluminum, titanium, zirconium, etc. The hydrolyzate of the metal alkoxide; silicone monomer or silicone oligomer can be used alone or in combination.

A particularly preferred transparent layer has a high surface hardness.
SiO with a relatively low refractive index₂ Is a thin film of. This S
iO₂ As an example of a material capable of forming a thin film, for example, the following formula M (OR)_mR_n (In the formula, M is Si and R is C₁~ C_FourWith an alkyl group of
Yes, m is an integer of 1 to 4, and n is an integer of 0 to 3.
And m + n is 4), or
Include one or more mixtures of the partial hydrolysates
You can As an example of a compound of the above formula, especially the
Traethoxysilane (Si (OC₂H_Five) _Four) Is the thin film type
Performance, transparency, bondability with conductive layer, film strength and anti-reflection
It is preferably used from the viewpoint of performance.

The transparent layer may be made of various resins, metal oxides, composite oxides, nitrides, etc., or precursors capable of forming these by baking, so long as they can be set to have a refractive index different from that of the conductive layer. May be included.

The transparent layer can be formed by a method similar to the method used for forming the conductive layer, in which a coating liquid (transparent layer-forming coating material) containing the above components is uniformly applied to form a film. . Application is spin coating, roll coating, spray coating, barcode coating,
Any ordinary thin film coating technique such as dip coating, meniscus coating or gravure coating can be used. Among them, spin coating 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 100 ℃
The transparent layer 3 is obtained by baking at ~ 1000 ° C.

Generally, the antireflection property at the interface between layers in a multilayer thin film is determined by the refractive index and film thickness of the thin film, and the number of laminated thin films. An effective antireflection effect can be obtained by designing the thickness of each conductive layer and transparent layer in consideration of the number of laminated layers. In the multilayer film having antireflection ability,
When the wavelength of the reflected light to be prevented is λ, in the case of an antireflection film having a two-layer structure, the high refractive index layer and the low refractive index are respectively λ / 4, λ / 4, or λ / from the base material side. Reflection can be effectively prevented by setting the optical film thickness to 2, λ / 4. In the case of a three-layer antireflection film, λ is formed in the order of the medium refractive index layer, the high refractive index layer, and the low refractive index layer from the base material side.
It is effective to set the optical film thickness to / 4, λ / 2, λ / 4.

In particular, considering the ease of manufacture and the economical efficiency, as shown in FIG. 1, a SiO ₂ film (refractive index 1 having a relatively low refractive index and a hard coat property is formed on the upper layer of the conductive layer 2. .46) with a film thickness of λ / 4.

In the transparent conductive film of the present invention containing a conductive layer and one or more transparent layers, the conductive layer and the transparent layer may be baked sequentially or simultaneously. For example, a transparent conductive film-forming coating material is applied to the display surface of a display device, a transparent layer-forming coating material is applied to the upper surface of the display surface, and after drying, 100 ° C.
By collectively baking at a temperature of 0 ° C., a conductive layer and a transparent layer can be formed at the same time, and a low reflective transparent conductive film can be formed.

The outermost layer of the transparent conductive film 5 is preferably provided with a transparent layer (uneven layer) 4 having irregularities. The concavo-convex layer 4 has an effect of scattering the surface reflected light of the transparent conductive film 5 and giving an excellent antiglare property to the display surface. Silica is preferable as the material of the uneven layer 4 from the viewpoint of surface hardness and refractive index. The concavo-convex layer 4 is formed by applying a concavo-convex layer forming coating as the outermost layer of the transparent conductive film 5 by the above-mentioned various coating methods, and after drying, simultaneously with the conductive layer 1 and the transparent layer 2 or separately from 100 ° C. It can be formed by baking at a temperature of 1000 ° C. In particular, spray coating is suitable as a method for applying the uneven layer 4. The height difference between the concave and convex portions of the unevenness is preferably 5 nm or more and 500 nm or less.

At least one layer of the transparent conductive film 5 of the present invention 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, Perylene Orange, Perylene Scarlet, Perylene Red 17
8, perylene maroon, dioxazine violet, isoindoline yellow, Nikkell 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 white , Organic and inorganic pigments such as ultramarine, manganese violet, emerald green, dark blue, carbon black, and azo dyes, anthraquinone dyes, indigoid dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, quinoline dyes, nitro dyes, nitroso dyes , Benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes, perinone dyes and the like. These coloring materials can be used alone or in combination of two or more kinds.

When a coloring material is used, its type and amount are
It 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 (3) . A = log ₁₀ (I ₀ / I) = εCD (3) In formula (3) , I ₀ : incident light, I : transmitted light, C : color density,
D : light distance, ε : molar extinction coefficient.

When a colorant is used in the transparent conductive film of the present invention, a colorant having a molar absorption coefficient of ε> 10 is generally used. The blending amount of the coloring material changes depending on the molar extinction coefficient of the coloring material to be used, but the absorbance A of the laminated film or the single layer film containing the coloring material is 0.0004 to 0.0969abs.
It is preferable that the amount be within the range. If these conditions are not met , the transparency or antireflection effect
Or the transparency and antireflection effect are reduced. When the coloring material is blended in the conductive layer 2, the blending amount is preferably 20% by weight or less, and particularly preferably 10% by weight or less with respect to the metal content. If it exceeds 10% by weight, a decrease in conductivity is recognized, and if it exceeds 20% by weight, the electromagnetic wave shielding effect is impaired.

In the display device of the present invention, any one of the transparent conductive films 5 described above is formed on the display surface 1. In this display device, since the display surface 1 is prevented from being charged, dust or the like does not adhere to the display surface, electromagnetic waves are shielded to prevent various electromagnetic interference, and the image is excellent in light transmission. It is bright, the hue of the transmitted image is natural, the coating thickness is uniform, and the coating unevenness on the display surface is inconspicuous. Moreover, since the salt water resistance is high, the durability is high even in an environment exposed to salt fog. In addition to the conductive layer 2, the transparent layer 3 or the unevenness
When the layer 4, or the transparent layer 3 and the uneven layer 4 are formed, an excellent antireflection effect against external light or an antiglare effect is obtained.
The fruit, or the antireflection effect and the antiglare effect are also obtained.

[0032]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. As a stock solution common to Examples and Comparative Examples,
The following was adjusted. (Aqueous gold sol) An aqueous solution containing 0.15 mmol / l of chloroauric acid and 0.024 mmol / l of sodium borohydride were mixed, and the obtained colloidal dispersion was concentrated to give 0.102. An aqueous sol containing mol / l of fine gold particles was obtained. The average particle size of the fine gold particles was 6 nm. (Silver aqueous sol) sodium citrate dihydrate (14 g)
And an aqueous solution (60 g) in which ferrous sulfate (7.5 g) was dissolved.
While maintaining g) at 5 ° C., an aqueous solution (25 g) in which silver nitrate (2.5 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 an aqueous sol containing 0.185 mol / l of silver fine particles. The average particle size of fine silver particles is 10
was nm. (Colloidal silica) "Silica Doll 30" manufactured by Nippon Kagaku Kogyo Co., Ltd. was used. (Coating A for forming transparent layer) Tetraethoxysilane (0.8
g), 0.1 N hydrochloric acid (0.8 g) and ethyl alcohol (98.4 g) were mixed to form a uniform solution. (Coating for forming uneven layer B) Tetraethoxysilane (3.0
g), 0.1N hydrochloric acid (10 g) and ethyl alcohol (8
7.0 g) was mixed to form a uniform solution.

(Example 1) Preparation of coating material for forming transparent conductive film : Gold aqueous sol 23 g 1/100 N-NaOH 0.01 g Isopropyl alcohol 10 g Ethyl alcohol 66.99 g The obtained mixed solution was ultrasonically dispersed (BRANSON ULTRASONlCS).
"Sonifire 450" manufactured by the company) was dispersed to prepare a coating material for forming a transparent conductive film. In this paint, fine gold particles are Na
Almost all of them were aggregated by the addition of OH, and they were aggregates having a particle size in the range of 20 nm to 25 nm as observed by TEM.

Film formation : The above-mentioned coating material for forming a transparent conductive film is applied to the display surface of a cathode ray tube using a spin coater, and after drying, the above-mentioned coating material A for forming a transparent layer and a spin coater are similarly applied to this application surface. The cathode ray tube of Example 1 having an antireflection transparent conductive film was prepared by applying the above-mentioned composition, placing the cathode ray tube in a drier, and baking it at 150 ° C. for 1 hour to form a transparent conductive film.

(Example 2) Preparation of coating material for forming transparent conductive film : Gold aqueous sol 23 g 1/100 N-NaOH 0.01 g Isopropyl alcohol 10 g Colloidal silica 0.46 g Ethyl alcohol 66.53 g The above components were mixed and carried out. The same treatment as in Example 1 was carried out to prepare a transparent conductive film-forming coating material. Most of the gold fine particles in this paint were aggregates having a particle size in the range of 20 nm to 25 nm. The weight ratio of SiO ₂ / Au in the paint is 30.
It was / 100.

Film formation : Using the above-mentioned transparent conductive film forming coating material and transparent layer forming coating material A, a cathode ray tube of Example 2 having an antireflection transparent conductive film was processed in the same manner as in Example 1. Created.

(Example 3) Preparation of coating material for forming transparent conductive film : Gold aqueous sol 17 g Silver aqueous sol 1 g 1/100 N-NaOH 0.01 g Isopropyl alcohol 10 g Colloidal silica 0.36 g Ethyl alcohol 71.63 g The mixture was mixed and treated in the same manner as in Example 1 to prepare a transparent conductive film-forming coating material. Most of the gold fine particles and silver fine particles in this paint were aggregates having a particle size in the range of 20 nm to 25 nm. In addition, SiO ₂ / Ag / in the paint
The weight ratio of Au was 30/6/94.

Film formation : The cathode ray tube of Example 3 having an antireflection transparent conductive film was processed by using the above-mentioned transparent conductive film forming coating material and transparent layer forming coating material A in the same manner as in Example 1. Created.

(Example 4) The transparent conductive film-forming coating material used in Example 3 was applied to the display surface of a cathode ray tube using a spin coater, and after drying, the transparent layer-forming coating material A was applied to this coated surface. Similarly, it is applied by using a spin coater, and further, in order to form an uneven layer, the above-mentioned coating material B for forming an uneven layer is sprayed and laminated, and this cathode ray tube is put in a dryer and baked at 150 ° C. for 1 hour. Example 4 having a transparent conductive film having an antiglare property and an antireflection property by being buried and forming a transparent conductive film having a three-layer structure in which a concavo-convex layer was formed on the outermost layer.
The cathode ray tube of

Comparative Example 1 Preparation of a coating for forming a transparent conductive film : Silver 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 obtain a transparent conductive film forming coating. Prepared. In the coating material of Comparative Example 1, silver microparticles were uniformly dispersed and almost no agglomerates were observed by TEM.

Film formation : A cathode ray tube of Comparative Example 1 having an antireflection transparent conductive film was prepared by the same procedure as in Example 1 using the above-mentioned transparent conductive film forming coating material and transparent layer forming coating material A. Created.

(Comparative Example 2) Preparation of transparent conductive film forming coating material : Gold aqueous sol 50 g Isopropyl alcohol 10 g Ethyl alcohol 40 g The above components were mixed and treated in the same manner as in Example 1 to obtain a transparent conductive film forming coating material. Prepared. In the coating material of Comparative Example 2, fine gold particles were uniformly dispersed and almost no agglomerates were observed by TEM.

Film formation : A cathode ray tube of Comparative Example 2 having an antireflection transparent conductive film was prepared by using the above-mentioned transparent conductive film-forming coating material and transparent layer-forming coating material A and treating in the same manner as in Example 1. Created.

(Comparative Example 3) Preparation of transparent conductive film-forming coating material : Antimony-doped tin oxide fine powder 1.5 g (Sumitomo Osaka Cement Co., 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 78.2 g The above components were mixed and treated in the same manner as in Example 1 to prepare a transparent conductive film-forming coating material.

Film formation : A cathode ray tube of Comparative Example 3 having an antireflection transparent conductive film was processed by using the above-mentioned transparent conductive film forming coating material and transparent layer forming coating material A in the same manner as in Example 1. Created.

(Evaluation Measurement) The performance of the transparent conductive film formed on the cathode ray tube was measured by the following device or method, and the appearance was visually evaluated. Film thickness: Measured by SEM observation Surface resistance: "Loresta AP" manufactured by Mitsubishi Chemical (4
Terminal method) Electromagnetic wave shielding property: Calculated according to the above formula (1) based on 0.5 MHz salt water resistance: 0.5 MHz electromagnetic wave shielding effect after 3 days of salt water immersion scratch test Scratch test: under load of 1 kg, film at metal part of mechanical pencil tip Scratch the surface and visually evaluate the degree of scratches ○ : No scratch △ : Slightly scratched × : Scratched transmittance ： Tokyo Denshoku “Automatic Haze Met
er H III DP "Haze:" Automatic Haze Met "made by Tokyo Denshoku Co., Ltd.
er H III DP ”Gross: Variable angle gloss meter“ MODE ”made by Tokyo Denshoku Co., Ltd.
"LTC-108D" Incident angle 60 ° Transmittance difference: The difference between the maximum transmittance and the minimum transmittance in the visible light region was calculated using a Hitachi U-3500 type self-recording spectrophotometer (visible light The smaller the maximum - minimum transmittance difference in the region, the flatter the transmittance becomes, and the clearer the hue of the transmitted image becomes.
The color of the transmitted image becomes closer to black, and it becomes more vivid. ) Luminous reflectance: EG & G GAMMASCIENTIFIC “MODEL
"C-11" Reflective color: "CR-300" (C
White point in CIE chromaticity diagram using IE color system
The deviation distance from x = 0.3137, y = 0.3198 was expressed by √ (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 ○ △ : Slightly good, △ : Acceptable △ × : Slightly bad × : Bad film unevenness: Visual appearance uniformity evaluation ○ : Good ○ △ : Slightly good △ : Acceptable △ × : Slightly bad × : Bad The evaluation test results above are shown in Tables 1 and 2.

[0047]

[Table 1]

[Table 2]

From the results of Tables 1 and 2 above, the cathode ray tube of the present invention in which the transparent conductive film containing the agglomerates of the metal fine particles was formed was the conventional Comparative Examples 1 and 2 containing the uniformly dispersed metal fine particles. In comparison with Comparative Example 3 of the antimony-doped tin oxide system, the surface resistance and the electromagnetic wave shielding property are equal to or more than the value even if the film thickness is 1/2 or less, and the salt water resistance,
Excellent scratch resistance, excellent transparency, high transparency, and a small difference in transmittance so that the hue of the transmitted image is not impaired, there is less reflection, less coloring of reflected colors, and good visibility and uneven film. It can be seen that it is. In Example 4, since the uneven layer is formed as the outermost layer, the gloss is reduced, the reflection of external light is suppressed, and the transmitted image is easier to see.

[0049]

The transparent conductive film of the present invention is made of gold as a conductive material.
Containing agglomerates of metal particles, the agglomerates having a particle size of 5 nm
Since it has a conductive layer formed by applying a coating for forming a transparent conductive film having a thickness of ˜50 nm, the formed transparent conductive film has an extremely thin conductive layer and therefore has a visible light average. Despite its high transmittance, it has excellent electromagnetic wave shielding effect and antistatic effect. In particular, when an aggregate of fine gold particles is used, the hue of the transmitted image is natural, and durability is represented by salt water resistance. Is also excellent. Therefore, the display device of the present invention in which this transparent conductive film is formed on the display surface does not impair the hue of the transmitted image, has excellent antistatic properties, electromagnetic wave shielding properties, and chemical stability, and has a light transmission property. Since it is high, the transmitted image is bright and the unevenness of the film thickness of the coating film is not noticeable.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of a display device of the present invention.

[Explanation of symbols]

1: Display surface 2: Conductive layer 3: Transparent layer 4: uneven layer 5: Transparent conductive film

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-10-110123 (JP, A) JP-A-10-182191 (JP, A) JP-A-10-188680 (JP, A) International Publication 97/048107 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01B 1/22 H01B 5/14 C09D 5/24 H05K 9/00

Claims (9)

(57) [Claims] 1. A conductive material containing an aggregate of fine metal particles
However, the particle diameter of the aggregate is within the range of 5 nm to 50 nm.
A transparent conductive film forming coating, characterized in that that. 2. The coating material for forming a transparent conductive film according to claim 1, wherein the metal fine particles contain at least gold fine particles. 3. Fine silica particles having an average particle size of 100 nm or less
The transparent body according to claim 1 or 2, wherein the transparent body includes a child.
Paint for forming conductive film. 4. A transparent conductive film having a conductive layer formed by applying the transparent conductive film-forming coating composition according to claim 1, 2, or 3 . 5. The film thickness of the conductive layer is 10 nm to 50 nm.
5. The transparent conductor according to claim 4 , characterized in that
Electric membrane. 6. An upper layer or a lower layer of the conductive layer, or
The upper and lower layers, transparent layers of different at least one layer having a refractive index and said conductive layer is characterized in that it is laminated 請
The transparent conductive film according to claim 4 or 5. 7. A transparent layer having irregularities is laminated on the outermost layer.
The transparent conductive film according to claim 6, wherein the are. 8. The average visible light transmittance is 80% or more,
8. The transparent conductive material according to claim 4, wherein the surface resistance is 1 × 10 ⁵ Ω / □ or less.
film. 9. The method according to any one of claims 4 to 8.
A display device having a transparent conductive film formed on a display surface.