JP3302186B2 - Substrate with transparent conductive film, method for producing the same, and display device provided with the substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate having a transparent conductive film and a display device having the substrate as a front plate, and more particularly, to a transparent conductive film having excellent antireflection performance and excellent electromagnetic shielding effect. The present invention relates to a coated substrate, a method for manufacturing the same, and a display device including a front plate formed of such a transparent conductive coated substrate.

[0002]

BACKGROUND OF THE INVENTION Hitherto, for the purpose of preventing the surface of a transparent substrate such as a display panel such as a cathode ray tube, a fluorescent display tube, and a liquid crystal display panel from being charged and anti-reflective, an antistatic function has been provided on these surfaces. 2. Description of the Related Art A transparent film having an antireflection function has been formed.

As a method for obtaining a transparent substrate having such antistatic and antireflection functions, a conductive film having a high refractive index having an antistatic function is first formed on the surface of a transparent substrate. There is known a method of forming a transparent film having a lower refractive index than this film on the film.

For example, JP-A-5-290634 discloses a method in which a transparent conductive film is formed on a substrate, and then a transparent film having a lower refractive index than the transparent conductive film is formed on the transparent conductive film. A method for producing a substrate with a transparent conductive film to be formed and a substrate with an antistatic / antireflection film obtained by such a method are disclosed. Of these, the transparent conductive film is formed from a coating solution containing fine powder of tin oxide doped with antimony as a conductive substance.

Japanese Patent Application Laid-Open No. 5-341103 discloses a conductive coating containing a conductive substance formed on a base material, and an antireflection coating derived from a specific silicon compound on the conductive coating. Discloses a substrate with a conductive coating having excellent antireflection properties and antistatic properties obtained by forming the same.
Further, in this publication, as the conductive material, perchlorates such as alkali metals, alkaline earth metals, and transition metals;
Examples of the electrolyte include inorganic electrolytes such as thiocyanate, trifluoromethyl sulfate, and halide salts, and transparent conductive inorganic oxide fine particles such as tin oxide-based fine particles and indium oxide-based fine particles. It is stated that inorganic oxide fine particles are preferred.

[0006] Recently, the effect of electromagnetic waves emitted from a cathode ray tube (CRT) or the like on the human body has become a problem, and in addition to the conventional antistatic and antireflection functions, these electromagnetic waves and the emission of the electromagnetic waves are accompanied. It is desired to shield the electromagnetic field formed.

As one of the methods of shielding these, a method of forming a conductive film similar to the above-described antistatic film on the surface of a front panel of a display panel such as a cathode ray tube is known.

However, a conventional conductive film for the purpose of preventing static electricity only needs to have a surface resistance of at least about 10 ⁵ Ω / □, whereas a conductive film for electromagnetic shielding is sufficient. It is necessary to have a low surface resistance such as 10 ² to 10 ⁴ Ω / □.

When an attempt is made to form a conductive film having a low surface resistance using a conventional coating solution containing a conductive oxide such as Sb-doped tin oxide or Sn-doped indium oxide, the conventional antistatic coating is required. In this case, the film thickness must be larger than in the case of (1).

Therefore, a conductive film having an electromagnetic shielding effect is formed on the surface of the transparent substrate using a coating solution containing such Sb-doped tin oxide or Sn-doped indium oxide as a conductive material, and further formed thereon. In order to form a transparent laminated film having a function of electromagnetic shielding and anti-reflection, the conductive film formed from the coating solution as described above is 1.5 to Since it has a high refractive index of 2.0, it is necessary to design the optical film thickness of the conductive film so as to exhibit an antireflection effect in combination with a low refractive index film laminated thereon. The actual thickness of the conductive film must be about 100 to 200 nm. However, with such a film thickness, it is not possible to obtain a sufficient surface resistance to exhibit the electromagnetic shielding effect.

[0011] Also in the above-mentioned JP-A-5-290634 and JP-A-5-341103, the thickness of the conductive film is as small as, for example, about 0.1 μM (100 nm). It is about ⁷ Ω / □, and it is difficult to say that it has a function of electromagnetic shielding.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, has excellent antireflection performance, and has a resistance of 10 ² to 10 ⁴ Ω /.
Provided is a substrate with a transparent conductive film having a surface resistance of □ and excellent in electromagnetic shielding effect, a method for producing the same, and a display device provided with a front plate composed of such a substrate with a transparent conductive film. It is intended to be.

[0013]

SUMMARY OF THE INVENTION The substrate with a transparent conductive film according to the present invention comprises:
A transparent conductive fine particle layer made of metal fine particles having an average particle diameter of 2 to 200 nm is formed on a substrate, and a transparent film having a lower refractive index than the fine particle layer is formed on the fine particle layer. .

The method for producing a substrate with a transparent conductive film according to the present invention is a method for forming a transparent conductive fine particle layer comprising dispersing metal fine particles having an average particle size of 2 to 200 nm in water and / or an organic solvent. The liquid is applied on a substrate and dried to form a transparent conductive fine particle layer, and then a transparent film having a lower refractive index than the fine particle layer is formed on the fine particle layer.

[0015] A display device according to the present invention is characterized in that it has a front plate made of the above-mentioned substrate with a transparent conductive film.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Substrate with a transparent conductive film First, the substrate with a transparent conductive film according to the present invention will be specifically described.

In the substrate with a transparent conductive film according to the present invention,
A transparent conductive fine particle layer made of metal fine particles having an average particle size of 2 to 200 nm, preferably 5 to 100 nm is formed on a substrate such as a flat plate, a three-dimensional object, or a film made of glass, plastic, metal, ceramic, or the like. .

The metal fine particles used in the present invention include:
There is no particular limitation as long as the average particle size is within the above range. For example, Au, Ag, Pt, Pd, Rh, Cu, Fe, Ni, C
fine particles of metal such as o, Sn, In, Ti, Al, and Ta.

The average particle diameter of these metal fine particles is 200 nm.
If it exceeds, the absorption of light by the metal increases,
For this reason, the light transmittance of the particle layer is reduced, and at the same time, the haze is increased. When such a coated substrate is used, for example, as a front plate of a cathode ray tube, the resolution of a displayed image is reduced.

The average particle diameter of these metal fine particles is 2n.
If it is less than m, the surface resistance of the particle layer increases rapidly, and it is not possible to obtain a coating having a low resistance enough to achieve the object of the present invention.

In the present invention, the transparent conductive fine particle layer may be composed of only metal fine particles having an average particle diameter within the above range, and in addition to such metal fine particles, a conductive material other than metal fine particles may be used. It may contain fine particles, small amounts of additives such as organic or inorganic dyes or pigments.

Examples of the conductive fine particles other than the metal fine particles include:
Known transparent conductive inorganic oxide fine particles or colored conductive fine particles such as carbon can be used. Examples of the transparent conductive inorganic oxide fine particles include tin oxide, Sb, F
Or tin oxide, indium oxide doped with P,
Examples thereof include indium oxide, antimony oxide, and lower titanium oxide doped with Sn or F.

When the transparent conductive fine particle layer contains conductive fine particles other than metal fine particles, similar to the above metal fine particles,
The average particle size of these conductive fine particles is preferably 2 to 200 nm.

In particular, when the transparent conductive fine particle layer contains transparent conductive inorganic oxide fine particles in addition to the metal fine particles, the transparent conductive fine particle layer has excellent transparency compared to the case where the transparent conductive fine particle layer is composed of only the metal fine particles. The conductive fine particle layer can be formed on the substrate. In addition, when the transparent conductive fine particle layer contains conductive fine particles other than metal fine particles as described above, the transparent conductive fine particle layer is less expensive than the case where the transparent conductive fine particle layer is composed of only expensive metal fine particles. A coated substrate can be manufactured.

These transparent conductive fine particle layers may include a matrix that functions as a binder for the conductive fine particles. As such a matrix, a known matrix can be employed, and examples thereof include silica obtained from a polycondensate obtained by hydrolyzing an organosilicon compound such as alkoxysilane. Further, a synthetic resin for paint can be used as the matrix.

The amount of the conductive fine particles other than the metal fine particles and the matrix contained in the transparent conductive fine particle layer is determined to be 10 ¹⁰ Ω / cm depending on whether only the antistatic function is provided or the electromagnetic shielding function is provided. □ Arbitrarily adjusted within the range where the following surface resistance can be obtained, and each type, metal type of metal fine particles contained in the transparent conductive fine particle layer, average particle diameter, thickness of the transparent conductive fine particle layer, It depends on the material and thickness of the transparent coating formed on the transparent conductive fine particle layer,
It cannot be specified unambiguously. However, when obtaining a substrate with a transparent conductive film having a surface resistance of 10 ² to 10 ⁴ Ω / □ capable of exhibiting an electromagnetic shielding effect, the conductive material other than the metal fine particles contained in the transparent conductive fine particle layer is required. The fine particles are desirably 4 parts by weight or less per 1 part by weight of metal fine particles, and the content of the matrix is desirably 0.2 parts by weight or less per 1 part by weight of all the conductive fine particles.

The film thickness of the transparent conductive fine particle layer is excellent in consideration of the fact that the refractive index of the transparent conductive fine particle layer is usually 1.6 to 2.5. In order to exhibit the antireflection effect, it is desirable that the thickness be in the range of 50 to 200 nm.

The substrate with a transparent conductive film having the above-described transparent conductive fine particle layer has a wide range of surface resistance of 10 ¹⁰ Ω / □ or less, and among them, 10 ² to 10 ⁴ Ω. /
The substrate with a transparent conductive film having a surface resistance of □ has an excellent electromagnetic shielding effect. Therefore, this 10 ² to 10 ⁴ Ω
When the front plate or the like of a cathode ray tube is composed of a substrate having a transparent conductive film having a surface resistance of / □, the electromagnetic wave emitted from the front plate or the like, and the emission of such an electromagnetic wave, The resulting electromagnetic field can be shielded.

In the substrate with a transparent conductive film according to the present invention, a transparent film having a lower refractive index than the fine particle layer is further formed on the transparent conductive fine particle layer. This transparent film can be formed of, for example, silica having a refractive index of 1.45 after the film is formed, similarly to the matrix. The transparent coating is made of fine particles composed of a material having a low refractive index such as magnesium fluoride, and, if necessary, a small amount of conductive fine particles and / or added to such an extent that the transparency and antireflection performance of the transparent coating are not impaired. Agents such as dyes or pigments may be included.

The transparent coating as described above has a refractive index smaller than that of the transparent conductive fine particle layer, and is sufficiently large to provide a substrate with a transparent conductive coating excellent in antireflection performance. It has a refractive index difference from the layer.

The thickness of the transparent coating is preferably 100 to 100% for the substrate with a transparent conductive coating to exhibit an excellent antireflection effect.
It is desirable to be in the range of 300 nm. The substrate with a transparent conductive film according to the present invention includes a transparent conductive fine particle layer and a transparent coating as described above, a transparent conductive fine particle layer is formed on the substrate, and the transparent conductive fine particle layer is formed on the transparent conductive fine particle layer. and a transparent film is formed, ² 10 necessary for electromagnetic shielding 10 ⁴
It can be adjusted to have a surface resistance of Ω / □ and to have sufficient antireflection performance in the visible light region and the near infrared region. When a substrate with a transparent conductive film whose surface resistance and antireflection performance are adjusted as described above is used for a front plate of a display device such as a cathode ray tube from which an electromagnetic wave is emitted, the electromagnetic wave is generated with the emission of the electromagnetic wave. Electromagnetic fields can be shielded, and reflected light from the front panel can be prevented.

Method for Producing a Substrate with a Transparent Conductive Film Next, a method for producing the substrate with a transparent conductive film according to the present invention as described above will be described.

In the substrate with a transparent conductive film as described above, a transparent conductive fine particle layer composed of metal fine particles having an average particle size of 2 to 200 nm is formed on the substrate, and then the fine particle layer is formed on this fine particle layer. Is also produced by forming a transparent film having a low refractive index.

The transparent conductive fine particle layer as described above has an average particle size of 2 to 200 nm, preferably 5 to 100 nm on the substrate.
It can be formed by applying and drying a coating liquid for forming a transparent conductive fine particle layer formed by dispersing metal fine particles of nm in water and / or an organic solvent.

In the coating liquid for forming the transparent conductive fine particle layer, if necessary, conductive fine particles other than the above-mentioned metal fine particles and / or matrix forming components, and if necessary, a small amount of additives, for example, Contains dyes or pigments.

Among these, the conductive fine particles are used in the form of powder including metal fine particles or in a sol state dispersed in a dispersion medium such as water. Metal fine particles, conductive fine particles other than metal fine particles, the compounding amount of the matrix forming component,
As described above. That is, the amount of the conductive fine particles other than the metal fine particles is 4 parts by weight or less per 1 part by weight of the metal fine particles contained in the transparent conductive fine particle layer formed on the base material, and the content of the matrix is all the conductive fine particles. 1
In such an amount as to be 0.2 parts by weight or less per part by weight, metal fine particles, conductive fine particles other than metal fine particles, matrix forming components and additives are contained in the coating liquid for forming a transparent conductive fine particle layer used in the present invention. It is desirable to be included.

In the present specification, the matrix-forming component refers to a component that functions as a binder for a particulate component such as conductive fine particles. For example, when the matrix is silica, a hydrolytic polycondensable organic silicon compound or a silica sol is used. And so on.

Further, as the hydrolysis polycondensable organic silicon compounds, alkoxysilane represented by the following formula [I]: wherein _{R a Si (OR ') 4} -a ... [I] (wherein, R is vinyl Group, an aryl group, an acryl group, an alkyl group having 1 to 8 carbon atoms, a hydrogen atom or a halogen atom, and R ′ is a vinyl group, an aryl group, an acryl group, an alkyl group having 1 to 8 carbon atoms,- C ₂ H ₄ OC _n
H _{2n + 1} (n = 1 to 4) or a hydrogen atom, and a is 0
To 3).

Specific examples of such alkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraoctylsilane, methyltrimethylsilane,
Examples include methyltriethoxysilane, ethyltriethoxysilane, methyltriisopropoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, and the like.

As the matrix-forming component, for example, one or more of the above-mentioned alkoxysilanes can be used. When the alkoxysilane is hydrolyzed in a mixed solvent such as water-alcohol in the presence of an acid such as nitric acid, hydrochloric acid, or acetic acid, a silica polymer obtained by polycondensation of a hydrolyzate of alkoxysilane is obtained.

The hydrolysis of the alkoxysilane as described above is carried out by acid / SiO ₂ = 0.0001 to 0.05 (weight / weight) and water / SiO ₂ = 4 to 16 (mol / mol) (in the above formula, SiO ₂ is obtained by converting alkoxysilane to SiO ₂
It is the value converted to. It is preferable to carry out under the condition of).

In preparing the coating liquid for forming the transparent conductive fine particle layer used in the present invention, water and / or an organic solvent is used as a dispersion medium of the metal fine particles. Fine particles, and if necessary, conductive fine particles other than metal fine particles, other additives, and matrix forming components are added.

Among them, examples of the organic solvent include alcohols such as methanol, ethanol, propanol, butanol, diacetone alcohol, furfuryl alcohol, ethylene glycol and hexylene glycol;
Methyl acetate, esters such as ethyl acetate, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,
Examples thereof include ethers such as ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, acetylacetone, and acetoacetate; and one or more of these are used.

The solid content concentration in the coating liquid for forming the transparent conductive fine particle layer used in the present invention, ie, the concentration of the components forming the transparent conductive fine particle layer, depends on the fluidity of the coating liquid, the fine metal particles in the coating liquid, and the like. From the viewpoint of the dispersibility of the particulate component as described above, the content is preferably 15% by weight or less. When the coating liquid for forming a transparent conductive fine particle layer contains a matrix forming component, the concentration of the matrix forming component is a part of the solid content concentration. For example, when the matrix forming component is tetraethoxysilane In the case of, the concentration of the matrix forming component is a value converted into the SiO ₂ concentration.

In the coating liquid for forming a transparent conductive fine particle layer used in the present invention, cations such as alkali metal ions, ammonia ions and polyvalent metal ions, and inorganic anions such as mineral acids, which are present in the coating liquid. Ion, acetic acid,
It is preferable that the total amount of ion concentrations of organic anions such as formic acid is 10 mmol or less per 100 g of the total solids contained in the coating solution. In such a coating liquid for forming a transparent conductive fine particle layer, the granular component contained in the coating liquid,
In particular, the dispersion state of the conductive fine particles is improved, and a coating liquid containing almost no aggregated particles can be obtained. The monodispersed state of the particulate component in the coating liquid is maintained during the process of forming the transparent conductive fine particle layer. As a result, a transparent conductive fine particle layer in which the particulate component is monodispersed can be formed on the substrate. That is, no aggregated particles are observed in the transparent conductive fine particle layer formed from the coating solution having a low ion concentration as described above.
As described above, in the transparent conductive fine particle layer formed from the coating solution having a low ion concentration as described above, conductive fine particles such as metal fine particles can be dispersed well. It is possible to provide a transparent conductive fine particle layer having the same conductivity with less conductive fine particles as compared with the case where is aggregated. Further, a transparent conductive fine particle layer free from point defects and uneven thickness, which is considered to be caused by aggregation of the particulate components, can be formed on the substrate.

The deionizing method for obtaining a coating solution having a low ion concentration as described above may be a method in which the ion concentration finally contained in the coating solution falls within the above range. The method of the deionization treatment is not particularly limited, but a preferred method of the deionization treatment is any one of a dispersion liquid containing a particulate component used as a raw material of a coating liquid and / or a liquid containing a matrix forming component, and a coating liquid prepared from each liquid. With an cation exchange resin and / or an anion exchange resin, or a method of subjecting any of these liquids to a washing treatment using an ultrafiltration membrane.

When the transparent conductive fine particle layer is formed on the substrate, the above-mentioned coating liquid for forming a transparent conductive fine particle layer is applied to the substrate and dried to form the transparent conductive fine particle layer. Any method available can be employed. For example, as such a method, a coating solution for forming a transparent conductive fine particle layer is applied on a substrate by a method such as a dipping method, a spinner method, a spray method, a roll coater method, and a flexographic printing method.
Next, a method of drying the obtained coating film and the like can be mentioned.
The coating is usually dried at room temperature to 90 ° C., and when the coating solution contains a matrix-forming component, it is preferable to heat the dried coating to 150 ° C. or higher.

Further, when the coating solution contains a matrix-forming component, if necessary, after the coating step or the drying step, or during the drying step, the transparent liquid containing the uncured matrix-forming component may be used. By irradiating the conductive fine particle layer with electromagnetic waves having a shorter wavelength than visible light, or by exposing the transparent conductive fine particle layer to a gas atmosphere that promotes the curing reaction of the matrix forming component, the transparent conductive fine particle layer Curing of the contained matrix forming component is promoted, and the hardness of the transparent conductive fine particle layer may be increased. This gas treatment may be performed after the heat treatment.

As the electromagnetic wave to be applied to accelerate the curing of the matrix-forming component, ultraviolet rays, electron beams, X-rays, γ-rays and the like are used according to the type of the matrix-forming component. For example, in order to accelerate the curing of the UV-curable matrix-forming component, for example, a high-pressure mercury lamp having an emission intensity of about 250 nm and 360 nm and a light intensity of 10 mW / m ² or more is used as an ultraviolet light source, and UV rays having an energy amount of / cm ² or more are applied.

Further, among the matrix forming components,
There is a matrix-forming component whose curing is promoted by an active gas such as ammonia or ozone. A transparent conductive fine particle layer containing such a matrix-forming component is formed with a gas concentration of 10%.
0-100,000 ppm, preferably 1000-1
By performing the treatment for 1 to 60 minutes in a curing accelerating gas atmosphere having a concentration of 000 ppm, the curing of the matrix forming component can be greatly promoted.

In the present invention, after the transparent conductive fine particle layer is formed on the substrate as described above, a transparent film having a lower refractive index than this layer is further formed on the transparent conductive fine particle layer. .

The method for forming the transparent film is not particularly limited, and may be a vacuum deposition method,
A dry thin film forming method such as a sputtering method or an ion plating method, or a wet thin film forming method such as a dipping method, a spinner method, a spray method, a roll coater method, or a flexographic printing method as described above can be employed.

When the above transparent film is formed by a wet thin film forming method, a coating liquid for forming a transparent film in which the above-mentioned matrix forming component is dissolved or dispersed in water or an organic solvent as a transparent film forming component is used. be able to.

Further, the coating liquid for forming a transparent film contains fine particles composed of a low refractive index material such as magnesium fluoride as described above, and, if necessary, does not impair the transparency and antireflection performance of the transparent film. It may contain a relatively small amount of conductive fine particles and / or additives such as dyes or organic or inorganic pigments.

In this case, when the above-described deionization treatment is applied to the coating solution for forming a transparent film to reduce the ion concentration contained in the coating solution to within the above-mentioned range, the granular component of the transparent film is reduced. Dispersibility is good, and it is possible to provide a transparent film having an even thickness.

When the above-mentioned transparent film is formed by the wet thin film forming method, the transparent conductive fine particle layer is formed in the same manner as when the transparent conductive fine particle layer is formed from the coating liquid for forming the transparent conductive fine particle layer containing the matrix forming component. Can be formed on the conductive fine particle layer.

Further, the transparent conductive fine particle layer formed on the base material is preheated to about 40 to 90 ° C., and the coating liquid for forming a transparent film is sprayed on the transparent conductive fine particle layer while maintaining this temperature. Applying, after that, when the above-described heat treatment is performed, ring-shaped irregularities are formed on the surface of the coating,
An antiglare substrate with a transparent conductive coating with less glare is obtained.

Display Device Among the substrates with a transparent conductive film produced as described above, they have a surface resistance of 10 ² to 10 ⁴ Ω / □ required for electromagnetic shielding and a visible light range. A substrate with a transparent conductive film having sufficient antireflection performance in the near infrared region is used as a front plate of a display device.

The display device according to the present invention comprises a cathode ray tube (C
RT), a fluorescent display tube (FIP), a plasma display (PDP), a liquid crystal display (LCD), etc., which electrically displays an image, and is composed of a substrate with a transparent conductive film as described above. Equipped with a front plate.

When a display device having a conventional front panel is operated, an electromagnetic wave is emitted from the front panel at the same time that an image is displayed on the front panel, and this electromagnetic wave affects the human body of the observer. in the display device according to the front plate 10 ² -
Since it is composed of a substrate with a transparent conductive film having a surface resistance of 10 ⁴ Ω / □, it is possible to effectively shield such an electromagnetic wave and an electromagnetic field generated by emission of the electromagnetic wave.

When reflected light is generated on the front panel of the display device, the reflected image makes it difficult to see a displayed image. However, in the display device according to the present invention, the front panel is sufficiently in the visible light region and the near infrared region. Since it is composed of a substrate with a transparent conductive film having an excellent antireflection performance, such reflected light can be effectively prevented.

Further, the front plate of the cathode ray tube is composed of the substrate with a transparent conductive film according to the present invention, and among the transparent conductive films, at least one of the transparent conductive fine particle layer and the transparent film formed thereon. On the other hand, when a small amount of dye or pigment is contained, the dye or pigment absorbs light having a wavelength unique to each of them, thereby improving the contrast of a display image projected from the CRT.

[0063]

The substrate with a transparent conductive film according to the present invention comprises:
A transparent conductive fine particle layer is formed on a transparent substrate, and a transparent coating having a lower refractive index than that of the transparent conductive fine particle layer is formed on the transparent conductive fine particle layer.

According to the present invention, the transparent conductive fine particle layer contains fine metal particles as a conductive substance.
Even if the film thickness is reduced, a fine particle layer having a lower surface resistance than a conventional film containing only a conductive oxide can be formed. Therefore, a transparent film having a low refractive index is formed on the conductive fine particle layer. By forming, a substrate with a transparent conductive film having an excellent electromagnetic shielding effect and an excellent antireflection effect can be provided.

Further, when the ion concentration of cations and anions contained in the coating liquid for forming the transparent conductive fine particle layer used in the present invention is adjusted to a very small amount, the conductive fine particles in the coating liquid may be reduced. The dispersed state becomes extremely good, and this favorable dispersed state of the conductive fine particles is maintained even in the process of forming the conductive fine particle layer, and the fine particles do not aggregate.

As a result, a fine particle layer in which conductive fine particles are uniformly dispersed can be formed, so that even if the concentration of the conductive fine particles in the coating solution is made lower than before, a fine particle layer having the same conductivity can be obtained. be able to.

Thus, according to the present invention, 10 ²
A substrate with a transparent conductive film having a surface resistance of from 10 ⁴ Ω / □ to an anti-reflection property can be provided. Further, the display device according to the present invention, since the base material with a transparent conductive film having excellent surface resistance and anti-reflection performance as described above is used for the front plate, the anti-reflection effect is excellent, and at the same time, electromagnetic waves and Excellent electromagnetic field shielding effect.

[0068]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0069]

Production Examples a) Conductive Fine Particle Dispersion The colloidal solution of metal fine particles and the dispersion of conductive fine particles other than metal fine particles used in this example are shown in Table 1 below.

Among these, the colloidal solutions of Au, Ag, and Pd are each a colloidal solution manufactured by Vacuum Metallurgy Co., Ltd. The colloidal solution of Rh was prepared by the following method. Rhodium trichloride was added to a methanol / water mixed solvent (40 parts by weight of methanol / 60 parts by weight of water) so as to be 2% by weight in terms of metal Rh, and polyvinyl alcohol was added to metal Rh1.
0.01 part by weight per part by weight was added, and the mixture was heated at 90 ° C. for 5 hours in a flask equipped with a reflux condenser to obtain a Rh colloid solution.

Using Sb-doped tin oxide (Sb-SnO ₂ ) fine particles, Sn-doped indium oxide (Sn-In ₂ O ₃ ) fine particles and conductive carbon (manufactured by Tokai Carbon Co., Ltd.), mixed fine particles shown in Table 1 below A dispersion was prepared.

Of these, Sb-doped tin oxide fine particles, Sn
The doped indium oxide fine particles were prepared as follows. 333 g of Sb-doped tin oxide fine particles of potassium stannate and 69.5 g of tartar were added to pure water 101
An aqueous solution dissolved in 9 g was prepared. This aqueous solution is
The solution was added to 1876 g of pure water maintained at 0 ° C over 12 hours. During this time, the pH in the system was maintained at 10. From the obtained Sb-doped tin oxide hydrate dispersion, the Sb-doped tin oxide hydrate was filtered through an ultramembrane, washed, dried, and then calcined in air at 550 ° C. for 3 hours. S
b-doped tin oxide fine particles were obtained. A solution obtained by dissolving 79.9 g of Sn-doped indium oxide indium nitrate in 686 g of water and a solution obtained by dissolving 12.7 g of potassium stannate in a 10 wt% potassium hydroxide solution were prepared.

The solutions were kept at 10 ° C.
It was added to 00 g of pure water over 2 hours. During this time, the pH in the system was maintained at 11. The Sn-doped indium oxide hydrate dispersion was filtered and washed from the obtained Sn-doped indium oxide hydrate dispersion, dried, and then dried in air in air.
By firing at a temperature of 600 ° C. for 3 hours and further firing at a temperature of 600 ° C. for 2 hours in air, Sn-doped indium oxide fine particles were obtained.

[0074]

[Table 1]

B) Preparation of Liquid Containing Matrix-Forming Component A mixed solution of 50 g of ethyl orthosilicate (SiO ₂ : 28% by weight), 194.6 g of ethanol, 1.4 g of concentrated nitric acid and 34 g of pure water was stirred at room temperature for 5 hours. 5% by weight of SiO ₂
A liquid containing a matrix-forming component was prepared. c) Preparation of coating liquid for forming transparent film (upper layer) To a liquid containing the above matrix-forming component, a mixed solvent of ethanol / butanol / diacetone alcohol / isopropanol (2: 1: 1: 5 weight mixing ratio) was added, and Si was added.
A coating liquid for forming a transparent film having an O ₂ concentration of 1% by weight was prepared. d) Preparation of a coating liquid for forming a transparent conductive fine particle layer A transparent conductive fine particle layer shown in Table 2 was prepared from a colloidal solution of metal fine particles shown in Table 1, a dispersion of a conductive fine particle mixture, and a liquid containing a matrix forming component. Coating Solutions C-1 to C
-8 was prepared.

Each coating solution shown in Table 2 was applied to an amphoteric ion exchange resin (Diaion SM manufactured by Mitsubishi Kasei Co., Ltd.).
The ion concentration in each coating solution was adjusted by performing deionization treatment with NUPB).

The ion concentration in the coating solution was measured as follows. Alkali metal ion concentration and alkaline earth metal ion concentration were measured by atomic absorption spectrometry, other metal ion concentrations were measured by emission spectroscopy, and ammonium ion and anion ion concentrations were measured by potentiometric titration.

[0078]

[Table 2]

[0079]

EXAMPLES 1 TO 7 AND COMPARATIVE EXAMPLE 1 While maintaining the surface of a CRT panel glass (14 ") at a temperature of 40 DEG C., the spinner method was applied at 100 rpm for 90 seconds to form the transparent conductive fine particle layer. Liquids C-1 to C-8 were applied respectively.

Next, on the transparent conductive fine particle layer thus formed, the coating liquid for forming a transparent film was applied in the same manner as described above, and then fired under the conditions shown in Table 3 to obtain Examples 1 to 3. 7. A substrate with a transparent conductive film of Comparative Example 1 was obtained.

The surface resistance of these substrates having a transparent conductive film was measured with a surface resistance meter (LORESTA manufactured by Mitsubishi Yuka Co., Ltd.), and the reflectance was measured with a spectrophotometer (manufactured by Hitachi, Ltd.). And haze were measured with a haze computer (manufactured by Suga Test Instruments Co., Ltd.).

Table 3 shows the results.

[0083]

[Table 3]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H05K 9/00 H05K 9/00 V (56) References JP-A-5-290634 (JP, A) JP-A-5-190089 ( JP, A) JP-A-4-17398 (JP, A) JP-A-4-323309 (JP, A) JP-A-3-34211 (JP, A) JP-A-3-281784 (JP, A) Hei 6-212125 (JP, A) Japanese Patent Laid-Open No. 5-190091 (JP, A) Chihiro Kawashima, edited by "Science of New Industrial Materials B13. Inorganic Pigments", Kanehara Publishing, September 20, 1968, first edition, p. 25-37 (58) Field surveyed (Int.Cl. ⁷ , DB name) H01B 5/14 H01B 13/00 503 G02F 1/1333 500 G09F 9/30 370 H04N 5/65 H05K 9/00

Claims (8)

(57) [Claims] 1. A transparent conductive fine particle layer composed of metal fine particles having an average particle diameter of 2 to 200 nm is formed on a substrate, and a transparent film having a lower refractive index than the fine particle layer is formed on the fine particle layer. A substrate with a transparent conductive film, characterized by comprising: 2. The fine particle layer further comprises conductive fine particles other than metal fine particles.
The substrate with a transparent conductive film according to the above. 3. The substrate with a transparent conductive film according to claim 1, wherein the fine particle layer further contains a matrix. 4. The substrate with a transparent conductive film according to claim 3, wherein the matrix is made of silica. 5. A coating solution for forming a transparent conductive fine particle layer formed by dispersing metal fine particles having an average particle size of 2 to 200 nm in water and / or an organic solvent is coated on a substrate and dried to form a transparent liquid. A method for producing a substrate with a transparent conductive film, comprising: forming a conductive fine particle layer; and then forming a transparent coating having a lower refractive index than the fine particle layer on the fine particle layer. 6. The coating liquid according to claim 5, further comprising conductive fine particles other than metal fine particles.
3. The method for producing a substrate with a transparent conductive film according to item 1. 7. The coating liquid according to claim 5, wherein the coating liquid further contains a matrix forming component.
3. The method for producing a substrate with a transparent conductive film according to item 1. 8. A front plate comprising the substrate with a transparent conductive film according to claim 1, wherein a transparent conductive film is formed on an outer surface of the front plate. A display device characterized by the above-mentioned.