JPH10110123A - Coating material for forming transparent conductive membrane and its production, transparent conductive low reflective membrane and its production, and display with the transparent conductive low reflective membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating material for forming a transparent conductive membrane capable of providing an excellent conductivity, transparency, low discoloring properties and useful as a transparent, conductive and low reflective membrane by including a colloidal metal fine powder, a dispersed stabilizer adsorbed thereon, an aggregation inducer and water. SOLUTION: This coating material for forming a transparent conductive membrane comprises (A) a colloidal metal fine powder (e.g. the one made of gold, silver, copper, aluminum, etc., and containing fine particles having <=0.1μm average particle diameter and <=0.005μm first particle diameter), (B) a dispersion stabilizer adsorbed on the component A (e. g. a water-soluble polymer compound such as a carboxylic acid, a sulfonic acid, polyvinyl alcohol, etc.), (C) an aggregation inducer (e.g. an alkali metal ion or ammonium ion) for aggregating the component A when being dried and (D) water, and if necessary (E) a water-soluble solvent such as alcohols or cellosolves having a boiling point higher than that of the water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint for forming a transparent conductive film capable of forming a transparent conductive film having high transparency and conductivity and having excellent antistatic effects, electromagnetic wave shielding effects and antireflection effects. The present invention relates to a manufacturing method, a transparent conductive low-reflection film, a method for manufacturing the same, and a display device with a transparent conductive low-reflection film.

[0002]

2. Description of the Related Art In recent years, a paint for forming a transparent conductive film has been required to prevent electrostatic charge and shield electromagnetic waves. For example, it is widely used for the display surfaces of display devices such as cathode ray tubes and liquid crystal display devices, their surface covering materials, and the coating of window glass surfaces of buildings and automobiles. It has come to be widely used for the protection of electrical products.

Generally, it is known that a transparent substrate having a large dielectric constant, such as glass or plastic, is easily charged with static electricity. Therefore, on the display surface or window glass surface of a display device using such a transparent base material, there is known a problem that dust and dirt adhere to the display surface due to the static electricity, thereby deteriorating display quality and transparency. In addition, it has been found that electromagnetic waves generated from various electrical products have a negative effect on the human body and cause malfunctions of surrounding electric and electronic devices.Therefore, it is necessary to shield electromagnetic waves to prevent electrical leakage. Is growing.

For this reason, it is known that the above-mentioned various problems can be reduced by forming a transparent conductive film on the surface of a transparent substrate by coating the same with a transparent conductive film. A substrate with a transparent conductive film using a paint for use is being studied.
No. 7832 discloses a transparent conductive fine particle layer comprising metal fine particles having an average particle diameter of 2 to 200 nm formed on a substrate, and a transparent film having a lower refractive index than the fine particle layer formed on the fine particle layer. A substrate with a conductive coating has been proposed.

However, a transparent conductive fine particle layer composed of metal fine particles, such as a substrate with a transparent conductive film, does not always have sufficient conductivity, and has a plasma resonance absorption on the surface of the metal fine particles. Since the plasma resonance absorption of metals with good conductivity such as gold, silver, and copper exists in the visible light region (wavelength 400 to 700 nm), only strongly colored films unique to metal fine particles can be obtained. Met. The transparent conductive fine particle layer has a thickness of 50 to 200 nm.
, It was difficult to obtain sufficient transparency, and it was difficult to use it for applications requiring high transparency, such as display devices.

For this reason, it is possible to form a transparent conductive film having a function of preventing electrostatic charge, shielding electromagnetic waves including ultraviolet rays and infrared rays, and having excellent transparency and conductivity, and the transparent conductive film is strongly colored. It has been strongly desired to develop a paint for forming a transparent conductive film, which does not have any, and a transparent conductive low-reflection film using the paint for forming a transparent conductive film.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made of a transparent conductive material which is excellent in conductivity (antistatic property, electromagnetic wave shielding property), transparency and weak coloring property. It is an object of the present invention to provide a coating material for forming a film, a method for manufacturing the same, a transparent conductive low-reflection film, a method for manufacturing the same, and a display device with a transparent conductive low-reflection film.

[0008]

In order to achieve the above object, according to the present invention, a paint for forming a transparent conductive film according to claim 1 comprises a colloidal metal fine particle and a surface of the colloidal metal fine particle. A dispersion stabilizing agent, an aggregation inducer that aggregates the colloidal metal fine particles when the paint is dried, and at least water.

Further, the paint for forming a transparent conductive film according to the second aspect is characterized in that it contains at least one water-soluble solvent such as alcohols or cellosolves having a higher boiling point than water.

In a third aspect of the present invention, the dispersion stabilizing agent is a carboxylic acid or a sulfonic acid, or a water-soluble polymer compound such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyethylene glycol. It is characterized by.

[0011] The coating material for forming a transparent conductive film according to claim 4 is characterized in that the aggregation attractant is at least one of an alkali metal ion and an ammonium ion.

Further, in the paint for forming a transparent conductive film according to claim 5, the colloidal metal fine particles have an average particle diameter of 0.1 μm.
And at least fine particles having a primary particle diameter of 0.005 μm or less.

According to a sixth aspect of the present invention, in the coating material for forming a transparent conductive film, the colloidal metal fine particles may be at least one of gold, silver, copper, aluminum, nickel, iron, tin, indium and lead. Metal fine particles.

Further, in the paint for forming a transparent conductive film according to claim 7, the colloidal metal fine particles are silver colloidal metal fine particles.

According to a eighth aspect of the present invention, there is provided a method for producing a transparent conductive film-forming paint according to any one of the first to seventh aspects, wherein the metal salt is dissolved. A dispersion stabilizer and a reducing agent are introduced into the dispersion dispersed in a solution or slurry to form a dispersion of the colloidal metal fine particles having the dispersion stabilizer adsorbed on the surface, and the dispersion is aggregated in the dispersion. It is characterized by having an attractant coexist.

In a preferred embodiment of the present invention, the reducing agent comprises a divalent iron salt, a divalent tin salt, a trivalent cerium salt, or a trivalent titanium salt. It is characterized by being at least one selected.

Further, the transparent conductive low-reflection film according to claim 10 is a continuous metal film that is fused and continuous, and the cross-sectional shape of the metal film is uneven. And a low refractive index transparent film coated thereon.

Further, the transparent conductive low-reflection film according to the eleventh aspect is characterized in that the maximum height of the projections of the metal film formed in the uneven shape from the substrate surface is 30 nm or less.

The method for producing a transparent conductive low-reflection film according to claim 12 is the method for producing a transparent conductive low-reflection film according to claim 10 or 11, wherein the method comprises the steps of: The coating material for forming a transparent conductive film according to the above is applied and dried to form an agglomerated layer composed of agglomerated particles of metal fine particles. Then, the aggregated particles of the metal fine particles are melted, and the coating material for forming a low-refractive-index transparent film is cured.

Further, in the method for producing a transparent conductive low-reflection film according to claim 13, the heating temperature is 250 ° C. or less.

Further, in the method of manufacturing a transparent conductive low-reflection film according to claim 14, the aggregated particles of the metal fine particles have a particle size of
It is characterized by being at least 0.3 μm.

According to a fifteenth aspect of the present invention, there is provided a display device with a transparent conductive low-reflection film, wherein the transparent conductive low-reflection film according to the tenth or eleventh aspect is provided on the surface of a transparent substrate.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The transparent conductive film forming paint of the present invention comprises a colloidal metal fine particle, a dispersion stabilizer adsorbed on the surface of the colloidal metal fine particle, and the colloidal metal fine particle when the paint is dried. An aggregation inducer for aggregation,
Contains at least water. That is, the dispersion stabilizer is adsorbed on the surface of the colloidal metal fine particles to be dispersed, so that the colloidal metal fine particles are stably dispersed, and when the paint for forming the transparent conductive film is dried, the colloidal metal fine particles are dried. In order to make the particles aggregate, an aggregation inducer is mixed.

For the purpose of complementarily controlling the aggregation of the colloidal metal fine particles, it is preferable to incorporate a water-soluble solvent such as alcohols or cellosolves having a boiling point higher than that of water into the paint for forming a transparent conductive film. Examples of the water-soluble solvent having a higher boiling point than water include n-butanol, 2-butanol, pentanol, amyl alcohol, benzyl alcohol, cyclohexanol, furfuryl alcohol, tetrahydrofurfuryl alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, -At least one compound of methoxymethoxyethanol, 2-isopropoxyethanol, isoamyl cellosolve, hexyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether and the like is blended. The amount of the water-soluble solvent having a boiling point higher than that of water is not particularly limited, but varies depending on the drying temperature and the drying method of the coating film. Usually, it is preferable to add 0.5 to 30% by weight in the paint for forming a transparent conductive film.

Examples of the dispersion stabilizer used for stably dispersing the colloidal metal fine particles in the paint for forming a transparent conductive film include carboxylic acids such as citric acid, stearic acid, lauric acid and oleic acid, and phenyldiazoic acid. Sulfonic acid,
It is preferable to use a sulfonic acid such as dodecylbenzenesulfonic acid or a water-soluble polymer compound such as polyvinyl alcohol, polyvinylpyrrolidone, or polyethylene glycol. Further, it is preferable to use a basic water-soluble solvent such as N-methylpyrrolidone or methylformamide in order to further improve the dispersion stability of the colloidal metal fine particles.

Among them, citric acid has three carboxyl groups, and therefore, when adsorbed on the surface of the colloidal metal fine particles, the particle surface potential in the liquid is large and the citric acid in the paint for forming a transparent conductive film is used. The dispersion stability of the colloidal metal fine particles becomes the best.

In order to obtain high transparency and conductivity, it is necessary to agglomerate the colloidal metal fine particles when the transparent conductive film forming coating is dried on the substrate. For this reason, a component that causes an aggregating action is blended in the paint for forming a transparent conductive film. As an aggregation inducer for this purpose, sodium (N
a) It is preferable to use at least one of alkali metal ions such as potassium (K) and ammonium ions.

The compounding ratio of the aggregation inducer, such as an alkali metal ion or an ammonium ion, in the paint for forming a transparent conductive film is preferably about 30 to 300 ppm. If it is less than 30 ppm, the aggregation of the colloidal metal fine particles hardly occurs during drying, so that the effect of improving the transparency is hardly observed. On the other hand, if it exceeds 300 ppm, agglomeration becomes remarkable during drying, and the distance between the agglomerated metal fine particles becomes too large. Is difficult to obtain. Therefore, the conductivity is deteriorated, which is not preferable.

As the colloidal metal fine particles dispersed in the paint for forming a transparent conductive film, gold (Au), silver containing at least fine particles having an average particle diameter of 0.1 μm or less and a primary particle diameter of 0.005 μm or less are used. (Ag), aluminum (Al), nickel (Ni), iron (Fe), tin (S
n), indium (In) and lead (Pb) are preferred. Among them, the electric conductivity is good and the visible light region (wavelength
Silver (Ag) having no transition between bands at 400 to 700 nm) and having no metallic color is most preferred. The primary particle size is 0.0
When the fine particles having a particle size of not more than 05 μm are not contained, the fusion of the colloidal metal fine particles hardly occurs. As a result, a problem occurs in which a colored film is formed or sufficient conductivity cannot be obtained.

The mechanism of agglomeration of the colloidal metal fine particles occurring when the transparent conductive film forming paint is dried will be described below. When, for example, an alkali metal ion is added to a solution in which the colloidal metal fine particles having the dispersion stabilizer adsorbed thereon are dispersed, it is considered that the alkali metal ion exists in a state coordinated to the surface layer of the colloidal metal fine particles. For example, when sodium (Na) ions as an aggregation inducer are blended with colloidal metal fine particles having citric acid as a stabilizer adsorbed on the surface, the chemical formula is considered to be as shown below. .

[0031]

Embedded image

Generally, a water-soluble polymer compound such as carboxylic acid, sulfonic acid, or polyvinyl alcohol as a dispersion stabilizer functions to reduce the solubility of the water-soluble solvent in water. Therefore, when sodium (Na) ion as an aggregation inducer is coordinated to a part of the carboxyl groups of citric acid as described above, as the proportion of the water-soluble solvent in the transparent conductive film forming coating increases, Separation of the water-soluble solvent and water easily occurs. On the other hand, when the paint for forming a transparent conductive film is dried, the boiling point of the compounded water-soluble solvent is higher than that of water, so that the proportion of the water-soluble solvent in the coating film increases as the film is dried. As a result, the colloidal metal fine particles that are hydrophilic surfaces aggregate.

The amount of water in the paint for forming a transparent conductive film also varies depending on the type of water-soluble solvent to be blended.
It is preferable to add 50% by weight or more. If the amount of water is too small, the dispersion stability of the colloidal metal fine particles in the coating material for forming a transparent conductive film is poor, and sedimentation or the like is not preferred.

For the purpose of adjusting the refractive index, adjusting the conductivity, adjusting the color tone, adjusting the viscosity, and imparting the ultraviolet shielding property, the coating material for forming the transparent conductive film includes silica, alumina, zirconia, zinc oxide, and oxide. Inorganic oxide powders such as cerium, tin oxide and gallium oxide, or coloring components such as organic pigments, organic dyes and inorganic pigments may be blended. However, the amount of these additives is preferably 10% by weight or less based on the metal component. The reason for this is that when the content exceeds 10% by weight, the conductivity of the transparent conductive film decreases, and the coloring property increases, so that it becomes impractical. In addition, the transparent conductive film forming paint can be formed by a heat treatment such as drying of the applied film without adding a binder component. However, in order to increase the film strength, various coatings such as an electron beam curing type and a thermosetting type can be used. It is also possible to add a binder component, and it is possible to form a transparent conductive film having excellent conductivity by heat treatment at a low temperature of room temperature to about 200 ° C. Further, a solvent such as methyl alcohol, ethyl alcohol, or isopropyl alcohol can be added to the paint for forming a transparent conductive film.

In order to produce a coating for forming a transparent conductive film, a dispersion stabilizer and a reducing agent are introduced into a solution in which a metal salt is dissolved or dispersed in a slurry, and the dispersion stabilizer is applied to the surface. A dispersion of the adsorbed colloidal metal fine particles is formed, and the aggregation attractant is allowed to coexist in the dispersion.

The metal salt is at least one selected from inorganic metal salts, organic metal salts, and metal complexes in which a ligand such as ammonia, pyridine or imidazole is coordinated with the inorganic metal salt or the organic metal salt. Is preferred. Also,
Examples of the reducing agent include hydrogen gas, hydrides such as sodium borohydride and lithium borohydride, hydrazine, formaldehyde, and a metal salt solution having a higher ionization tendency than the metal to be reduced.

Among these reducing agents, metal salts having a higher ionization tendency than the metal to be reduced are preferable. In particular, divalent iron salts, divalent tin salts, trivalent cerium salts, and trivalent titanium salts are preferable. preferable. Examples of divalent iron salts include iron sulfate, iron nitrate, and iron chloride. Examples of divalent tin salts include tin chloride and tin iodide. Examples of trivalent cerium salts include cerium nitrate and cerium sulfate. As the salt, titanium chloride and the like are preferable because they are industrially easily available.

As described above, it is preferable to use a metal salt having a higher ionization tendency than the metal species to be reduced as the reducing agent, because the dispersion stabilizing agent adsorbs to the surface of the colloidal metal fine particles. This is because the derived metal ions are simultaneously taken into the surface of the colloidal metal fine particles, and the metal ions derived from the reducing agent lower the melting temperature of the colloidal metal fine particles. In addition, in order to lower the melting temperature of the colloidal metal fine particles, the primary particle diameter is 0.005.
It is also important to include colloidal metal fine particles containing at least metal fine particles of μm or less in the paint for forming a transparent conductive film.

In the reduction reaction using a reducing agent, a dispersion stabilizer which forms a protective layer by adsorbing on the surface of the formed colloidal metal fine particles is added. As a result, miniaturization and stabilization of the generated colloidal metal fine particles are achieved.

As a means for allowing the aggregation inducer to coexist in the coating for forming a transparent conductive film, carboxylic acid or sulfonic acid used as a dispersion stabilizer may be converted into an alkali metal salt or an ammonium salt, for example, sodium citrate or citric acid. Means of adding ammonium, sodium stearate, sodium oleate, sodium dodecylbenzenesulfonate, etc., or an aqueous solution of an alkali metal hydroxide such as caustic soda, means of adding aqueous ammonia, or when forming colloidal metal fine particles In addition, means for controlling the amounts of alkali metal ions and ammonium ions mixed with the raw material components at the time of desalting may be used.

In the prepared suspension of colloidal metal fine particles, nitrate ion, sulfate ion,
Since organic acid ions, alkali metal ions, ammonium ions, metal ions, etc. are mixed, desalination is carried out by a usual method such as ultrafiltration, ion exchange, electrodialysis, etc., and aggregation is induced in the paint for forming a transparent conductive film. The amount of an alkali metal ion or ammonium ion as an agent or a metal ion derived from a reducing agent is adjusted.

As described above, the paint for forming a transparent conductive film contains an inorganic oxide, a coloring component, a binder component,
It is possible to add a solvent such as isopropyl alcohol, but when these various additives are added and dispersed, an ordinary disperser such as an ultrasonic disperser or a sand mill can be used.

As shown in FIG. 1, the formed transparent conductive low-reflection film is a fused and continuous metal film,
A transparent conductive film (high-refractive-index film) 2 having high conductivity formed on the surface of the substrate 1, the metal film having an uneven cross section.
And a low refractive index transparent film 3 formed on the transparent conductive film.

That is, the transparent conductive low-reflection film is higher than a conventional transparent conductive film in which metal fine particles are laminated on a substrate, because the transparent conductive film is a continuous uneven film formed by fusing a metal. It is a film that can be regarded as a pseudo-refractive index continuous change film formed by a combination of a low refractive index film and a high refractive index film. An anti-reflection effect is obtained. The thickness of the transparent conductive low-reflection film is preferably 0.05 to 0.2 μm from the viewpoint of transparency and low reflectivity.

In the transparent conductive film, as schematically shown in FIG. 1, a metal is fused to the substrate 1 in an uneven shape, the metal film is thin in the concave portion, and is thinner than the convex portion. By selecting a metal having a relatively large concave portion to reduce the average film thickness and a metal having a small absorption in the visible light region, the light transmittance is remarkably improved, so that the total light transmittance is increased to about 80%. Thus, a high transmittance having no practical problem can be obtained.

In order to form such a continuous metal film having a high transmittance, the amounts of the aggregation inducer, the dispersion stabilizer and the water-soluble solvent in the paint for forming the transparent conductive film are controlled. The particle size of the aggregated colloidal metal particles
By adjusting the distance to 0.3 μm or more, it is preferable that the distance between the protrusions (or between the recesses) of the obtained transparent conductive film is 0.3 μm or more.

Further, since the transparent conductive film is a continuous metal film fused to the substrate 1, it is possible to obtain a transparent film having little coloring characteristic of a metal in addition to the above-mentioned high transparency. In addition to this, there is no factor that lowers the electron mobility such as grain boundaries and voids, and conductivity close to the original value of the metal can be obtained. The maximum height of the projections of the transparent conductive film from the substrate surface is 30 nm (0.03 μm) from the viewpoint of transparency.
m)

The relationship between the electromagnetic wave shielding effect and the volume resistivity of the conductive film is generally expressed as follows.

(Equation 1) Here, S (dB); electromagnetic wave shielding effect ρ (Ω · cm); volume resistivity of conductive film f (MHz); electromagnetic wave frequency t (cm);

The thickness of the transparent conductive film formed from the paint for forming a transparent conductive film of the present invention is 1 μm from the viewpoint of transmittance.
(1 × 10 ⁻⁴ cm) or less is preferable.

[0050]

(Equation 2) Becomes

The larger the value of S, the greater the electromagnetic wave shielding effect. When S> 30 dB, it is considered that the electromagnetic wave shielding effect is obtained. In addition, the frequency of the electromagnetic wave to be regulated is generally in the range of 10 KHz to 1000 MHz, so that the conductivity of the transparent conductive film needs to have a volume resistivity of 10 ³ Ω · cm or less. That is, the lower the specific resistance value of the transparent conductive film, the more effectively it is possible to effectively shield electromagnetic waves of a wider range of frequencies. In the transparent conductive film, since a continuous transparent conductive film is formed by fusing the colloidal metal fine particles, the conductivity can be easily ensured even if the film thickness is small, and in addition to the effect of preventing electrostatic charge, Excellent electromagnetic wave shielding effect.

The transparent conductive film is formed by applying the transparent conductive film forming paint on the surface of a substrate such as glass or plastic,
After drying at a temperature of about 30 to 100 ° C., the colloidal metal fine particles are agglomerated as agglomerated particles 2a having a particle size of about 0.3 μm or more (FIG. 2A), and then a low refractive index transparent film forming paint is applied. By performing a heat treatment at a temperature of about 80 to 250 ° C., the aggregated particles 2a are melted to form a continuous transparent conductive film having irregularities (FIG. 2B).

The process of forming the transparent conductive low-reflection film is based on the base material 1
When the paint for forming a transparent conductive film is applied to the surface, the surface before the drying becomes a surface on which a uniform coating film 4 is formed as shown in FIG. 3A, and as the drying proceeds, the colloidal metal fine particles aggregate. As shown in FIG. 3B, the agglomerated particles 2a are scattered on the surface of the base material 1 in a state of being raised like an island. When applied, the aggregated particles 2a are wrapped in the low-refractive-index film 3 as shown in FIG. 3 (c), and after the heat treatment, the metal fine particles whose aggregation has been loosened as shown in FIG. 3 (d) Are spread from each other and fused to each other to form a mesh film state having irregularities connected entirely from the dotted state, and a low refractive index transparent film 3 is laminated on the mesh-shaped transparent conductive film 2 having the irregularities. A transparent conductive low-reflection film with a uniform and smooth surface It is.

In the coating material for forming a low refractive index transparent film, as a binder component, an organic resin such as a polyester resin, an acrylic resin, an epoxy resin, a melamine resin, a urethane resin, a butyral resin, an ultraviolet curable resin, silicon, titanium, and zirconium. It is possible to add a hydrolyzate of a metal alkoxide such as, or an inorganic binder containing a silicone monomer, a silicone oligomer, or the like. In particular, from the viewpoint of film strength and refractive index, M (OR) _m R _n [M = Si, Ti, Zr. m + n = 4, m = 1 to 4] [R = C _{1 to} C ₄ alkyl group n = 0 to 3] or a partially hydrolyzed condensate is preferably used alone or as a mixture.

However, when a water-insoluble binder is used, the colloidal metal fine particles are mixed with a coupling agent such as a silicone coupling agent or a titanate coupling agent, a carboxylate, a polycarboxylate, or a phosphate. It is necessary to use colloidal metal fine particles which have been subjected to a lipophilic surface treatment with a lipophilic surface treating agent such as a salt, a sulfonate, or a polysulfonate.

The coating methods for the transparent conductive film forming paint and the low refractive index transparent film forming paint include spin coating,
Usual film forming methods such as a roll coating method, a spray method, a bar coating method, a dipping method, and a meniscus coating method can be used. The film forming conditions are designed in consideration of desired conductivity and transparency.

[0057]

【Example】

A. Preparation of silver colloid Solution containing 50 g of sodium citrate dihydrate 1500
g of silver citrate was added to the mixture to form a suspension, and the suspension was maintained at 5 ° C.
900 g of the dissolved g were added in about 5 seconds to form a silver colloid. This silver colloid dispersion liquid was subjected to ultrafiltration-type desalting and washing equipment to adjust the amount of impurity ions (mainly sodium (Na) ions and iron (Fe) ions), and then concentrated to obtain a silver colloid having a solid content of 1.0% by weight. A dispersion was obtained.

According to the transmission electron microscope observation, the silver colloid particles in the silver colloid dispersion have a primary particle diameter of 0.0
02 to 0.02 μm, of which the primary particle diameter is 0.00
It contained about 20% by number of silver colloid particles of 2 to 0.005 μm. Further, the content of sodium (Na) ion and iron (Fe) ion in the silver colloid dispersion is as follows:
According to the analysis results by the atomic absorption method, each was 15 pp
m, 60 ppm. Further, the above silver colloid dispersion is
After drying at 60 ° C., the silver colloid particles were taken out and subjected to differential thermal analysis. As a result, it was found that 22% by weight of citric acid was adsorbed on the silver colloid particles.

B. Preparation of paint for forming low refractive index transparent film 2.4 g of tetraethoxysilane, 0.8 g of 0.1 N nitric acid,
Mix with 98.4 g of ethyl alcohol to make a uniform solution,
This solution was used as a stock solution. (1) Low refractive index transparent film forming paint (a) Ethanol is added to the above undiluted solution at a weight ratio of 1: 1 to form a uniform solution, which is referred to as a low refractive index transparent film forming paint (a). did. (2) Low refractive index transparent film forming paint (b) Ethanol is added to the stock solution at a weight ratio of 1: 2 to form a uniform solution, which is referred to as low refractive index transparent film forming paint (b). did. (3) Low refractive index transparent film forming paint (c) Ethanol is added to the stock solution at a weight ratio of 1: 3 to form a uniform solution, which is referred to as low refractive index transparent film forming paint (c). did.

C. Film Evaluation Method The film was evaluated using the apparatus described below on the right side. (1) Surface resistance: Loresta AP manufactured by Mitsubishi Yuka Co., Ltd. (4 end needle method) (2) Haze: Automatic Haze Meter manufactured by Tokyo Denshoku Co., Ltd. (3) Transmittance: U-Best 50 manufactured by JASCO Corporation ( (Measurement wavelength 450nm, 550nm) (4) Reflectance: manufactured by JASCO Corporation (specular reflection at an incident angle of 5 degrees, measurement wavelength 550nm) (5) Film thickness: DEKTAK (contact pointer type film thickness meter)

Example 1 A. Preparation of Transparent Conductive Film Forming Paint (1) Silver colloid dispersion 50.00 g 0.1% NaOH aqueous solution 2.23 g pure water 27.77 g isopropyl alcohol (IPA) 10.00 g butyl cellosolve 10.00 g was mixed and ultrasonically dispersed The dispersion was performed by a machine to prepare a coating material for forming a transparent conductive film. B. Film formation The above-mentioned paint (1) for forming a transparent conductive film was coated on a soda-lime glass plate using a spin coater at a rotation speed of 150 rpm for a time.
After applying for 30 seconds and drying with a dryer,
Subsequently, the coating material (b) for forming a low-refractive-index transparent film was applied using a spin coater under the conditions of a rotation speed of 150 rpm and a time of 30 seconds, and baked in a dryer at a temperature of 150 ° C. for 1 hour to obtain Example 1. Was formed.
Tables 1 and 2 show the evaluation results of the obtained films.

Example 2 A. Preparation of Transparent Conductive Film Forming Paint (2) 50.00 g of the above-mentioned silver colloid dispersion solution 2.23 g of a 0.1% aqueous NaOH solution 24.77 g of pure water 10.00 g of isopropyl alcohol (IPA) 10.00 g of butyl cellosolve 3.00 g of methylformamide Then, the mixture was dispersed by an ultrasonic dispersing machine to prepare a paint for forming a transparent conductive film. B. Film formation A transparent conductive low-reflection film as Example 2 was formed in the same manner as in Example 1 except that the transparent conductive film forming paint (2) was used. Tables 1 and 2 show the evaluation results of the obtained films. As shown in FIG. 4, the transparent conductive low-reflection film has a very high light transmittance of 70% or more in the visible light region, and further, as shown in FIG. wavelength
It has been found that the film has a very good antireflection property with a reflectance of 1% or less in the region of 480 to 750 nm.

Example 3 A. Preparation of paint (3) for forming transparent conductive film Dispersion of the silver colloid (a) 50.00 g 0.1% NaOH aqueous solution 2.23 g pure water 24.77 g isopropyl alcohol (IPA) 10.00 g butyl cellosolve 10.00 g N-methylpyrrolidone 3.00 g was blended and dispersed by an ultrasonic disperser to prepare a paint for forming a transparent conductive film. B. Film formation A transparent conductive low-reflection film as Example 3 was formed in the same manner as in Example 1 except that the paint (3) for forming a transparent conductive film was used. Tables 1 and 2 show the evaluation results of the obtained films.

Example 4 A. Preparation of Transparent Conductive Film Forming Coating (4) Silver colloid dispersion 50.00 g 0.1% NaOH aqueous solution 5.13 g pure water 21.87 g isopropyl alcohol (IPA) 10.00 g butyl cellosolve 10.00 g methylformaldehyde 3.00 g Then, the mixture was dispersed by an ultrasonic dispersing machine to prepare a paint for forming a transparent conductive film. B. Film formation A transparent conductive low-reflection film as Example 4 was formed in the same manner as in Example 1 except that the transparent conductive film forming paint (4) was used. Tables 1 and 2 show the evaluation results of the obtained films.

Example 5 A. Preparation of Transparent Conductive Film Forming Coating (5) Silver Colloid Dispersion 50.00 g 0.1% NaOH aqueous solution 10.50 g Pure water 16.50 g Isopropyl alcohol (IPA) 10.00 g Butyl cellosolve 10.00 g Methyl formaldehyde 3.00 g Then, the mixture was dispersed by an ultrasonic dispersing machine to prepare a paint for forming a transparent conductive film. B. Film formation A transparent conductive low-reflection film as Example 5 was formed in the same manner as in Example 1 except that the transparent conductive film forming paint (5) was used. Tables 1 and 2 show the evaluation results of the obtained films.

Example 6 A. Preparation of Transparent Conductive Film Forming Paint (6) 50.00 g of the above-mentioned silver colloid dispersion liquid 0.150% aqueous NaOH 14.50 g pure water 12.50 g isopropyl alcohol (IPA) 10.00 g butyl cellosolve 10.00 g methylformaldehyde 3.00 g Then, the mixture was dispersed by an ultrasonic dispersing machine to prepare a paint for forming a transparent conductive film. B. Film formation A transparent conductive low-reflection film as Example 6 was formed in the same manner as in Example 1 except that the transparent conductive film forming paint (6) was used. Tables 1 and 2 show the evaluation results of the obtained films.

Example 7 B. Film formation A transparent conductive low-reflection film as Example 7 was formed in accordance with Example 1 except that the transparent conductive film forming paint (2) and the low refractive index transparent film forming paint (a) were used. did. Tables 1 and 2 show the evaluation results of the obtained films.

Example 8 B. Film formation was performed except that the transparent conductive film forming paint (2) and the low refractive index transparent film forming paint (c) were used, and that the number of revolutions of the spin coater during the formation of the transparent conductive film was 120 rpm. According to Example 1, a transparent conductive low-reflection film as Example 8 was formed. Tables 1 and 2 show the evaluation results of the obtained films.

From the results shown in Tables 1 and 2, the transparent conductive low-reflection film of the present invention has a surface resistance of 1 × 10 ² to 9 × 10 ² Ω · c.
m, haze value is 0.1 to 0.5 (prior art, for example,
In the embodiment of −77832, the surface resistance is 10 ³ to 10 ⁴ Ω.
Cm, haze value is 0.3 to 1.9), transmittance of light with a wavelength of 420 nm is 68 to 73%, and transmittance of light with a wavelength of 550 nm is 7
6-82%, transmitted light is only colored yellow, and luminous reflectance is 0.5-3.2, so it has excellent conductivity and transparency, and does not have the coloring characteristic of metal fine particles. Turns out.

[0070]

[Table 1]

[0071]

[Table 2]

[0072]

As described above, according to the present invention, since the dispersion stabilizer is adsorbed on the surface of the colloidal metal fine particles in the coating material for forming a transparent conductive film according to the first aspect, the coating material contains an aggregation inducer. It is excellent in dispersibility even in medium, and because the aggregation inducer is blended, during drying after application, the aggregation effect of the aggregation inducer becomes stronger with decreasing water, and it is dispersed in colloidal form. The fine metal particles are agglomerated, the metal fine particles do not spread uniformly, and the distribution of the metal fine particles in the form of aggregated particles occurs, and the transparent conductive film obtained after the film forming process involving heating is fused. As a result, a transparent conductive film having a concavo-convex shape is formed as a continuous metal film, and thus has both excellent transparency and conductivity, and does not have coloring properties unique to metal fine particles.

In the paint for forming a transparent conductive film according to the second aspect, a water-soluble solvent having a boiling point higher than that of water is blended for the purpose of complementing the aggregating action of the aggregating attractant, so that the water content during drying after coating is reduced. With the decrease in agglomeration, the coagulation action becomes stronger, and the transparency and conductivity of the transparent conductive film become excellent.

In the paint for forming a transparent conductive film according to the third aspect, since a water-soluble polymer compound is blended as a dispersion stabilizer, the paint is strongly adsorbed on the surface of the colloidal metal fine particles and is contained in the liquid of the metal fine particles. Increase the particle surface potential,
In order to suppress the aggregation effect of the aggregation inducer, thereby improving the dispersibility of the colloidal metal fine particles, and at the time of drying after coating, to reduce the solubility of the water-soluble solvent in water,
Aggregation of metal fine particles is promoted.

In the coating for forming a transparent conductive film according to the fourth aspect, at least one of an alkaline earth metal ion and an ammonium ion is blended as a cohesion inducer. The coagulation action becomes particularly strong, and the transparency and conductivity of the transparent conductive film become excellent.

In the coating material for forming a transparent conductive film according to the fifth aspect, the average particle diameter of the colloidal metal fine particles is 0.1 μm or less and at least the fine particles having a primary particle diameter of 0.005 μm or less are contained. , Wavelength 400-700 n
m has excellent transparency in the visible light region, improves the transparency of the transparent conductive film, promotes fusion of the colloidal metal fine particles, and provides a transparent conductive film having excellent conductivity without coloring. Can be formed.

In the paint for forming a transparent conductive film according to the sixth aspect, since fine metal particles having excellent conductivity are used, the conductivity of the transparent conductive film is improved, and the antistatic effect and the electromagnetic wave shielding effect are improved. I do.

In the paint for forming a transparent conductive film according to the seventh aspect, since fine silver particles having excellent conductivity are used, the conductivity of the transparent conductive film is improved, and the antistatic effect and the electromagnetic wave shielding effect are improved. As a result, a transparent film without coloring can be obtained.

In the method for producing a coating material for forming a transparent conductive film according to claim 8, fine metal fine particles are precipitated from a metal source.
Colloidal metal fine particles having a dispersion stabilizer adsorbed on the surface can be produced, and a paint for forming a transparent conductive film containing an aggregation inducer can be produced.

In the method for producing a paint for forming a transparent conductive film according to the ninth aspect, the reducing agent is easily available industrially, so that it is easy to use, suitable for mass production, and can improve productivity.

According to a tenth aspect of the present invention, the transparent conductive low-reflection film is a continuous metal film which is fused and continuous, and has a concave-convex cross-sectional shape and a low-refractive-index transparent film formed thereon. Because it is composed, it has both transparency of visible light and antistatic / electromagnetic shielding properties, high transparency,
A low-reflection film having good conductivity can be provided.

In the transparent conductive low-reflection film according to the eleventh aspect, the height of the projecting portion of the transparent conductive film from the substrate surface does not exceed 30 nm at the maximum, so that the transparent conductive film has high transparency. Become.

In the method for producing a transparent conductive low-reflection film according to the twelfth aspect, the low-refractive-index transparent film is laminated on the metal film continuously formed by melting the aggregated particles of the metal fine particles. The convex portions have high conductivity, and the concave portions have high visible light transmittance, so that a pseudo refractive index gradient film can be formed, and a transparent and highly conductive low-reflection film can be formed.

In the method for producing a transparent conductive low-reflection film according to the thirteenth aspect, since the processing temperature at the time of film formation is relatively low, it is possible to reduce restrictions on usable substrates and steps.

In the method for producing a transparent conductive low-reflection film according to the fourteenth aspect, by forming the particle size after aggregation to be relatively large, a continuous metal film having irregularities can be formed at the time of melting. Furthermore, a pseudo-refractive-index gradient film can be formed by coating a low-refractive-index transparent film thereon.
It is possible to form a transparent conductive low-reflection film having a smaller film thickness than before.

In the display device with a transparent conductive low-reflection film according to the fifteenth aspect, a transparent conductive low-reflection film serving as a pseudo-refractive-index gradient film is provided on the surface of the transparent base material. A display device having an antistatic effect and an electromagnetic wave shielding effect, having no coloring, and having an excellent antireflection effect can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a transparent conductive low-reflection film according to the present invention.

FIG. 2 is a vertical cross-sectional explanatory view showing a process of forming a transparent conductive low-reflection film according to the present invention, and (A) is a vertical cross-sectional explanatory view showing a state after application and drying in which aggregated particles are formed on a substrate; (B)
FIG. 3 is an explanatory longitudinal sectional view showing a state in which a transparent conductive low-reflection film is formed on a substrate.

FIG. 3 is an explanatory view showing a process of manufacturing a transparent conductive low-reflection film according to the present invention. FIG. 3 (A) is a longitudinal sectional view showing a state before a transparent conductive film forming paint of the present invention is applied to a base material before drying. Explanatory drawing, (b) is a longitudinal sectional explanatory view showing a state after the drying process,
(C) is an explanatory longitudinal sectional view showing a state after applying a coating material for forming a low refractive index transparent film, and (D) is an explanatory longitudinal sectional view showing a state after a melting treatment.

FIG. 4 is a graph showing a transmission spectrum of a transparent conductive low-reflection film obtained in Example 2 according to the present invention.

FIG. 5 is a graph showing a reflection spectrum of a transparent conductive low-reflection film obtained in Example 2 according to the present invention.

[Explanation of symbols]

 1 base material 2 transparent conductive film (high refractive index film) 3 low refractive index transparent film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09C 3/10 C09C 3/10 C09D 5/00 C09D 5/00 P 5/38 5/38 7/12 7/12 AZ H05K 9/00 H05K 9/00 W

Claims (15)

[Claims] Claims: 1. A composition comprising at least one of colloidal metal fine particles, a dispersion stabilizer adsorbed on the surface of the colloidal metal fine particles, an aggregation inducer for aggregating the colloidal metal fine particles when a paint is dried, and water. A paint for forming a transparent conductive film, comprising: 2. The coating for forming a transparent conductive film according to claim 1, further comprising at least one water-soluble solvent having a higher boiling point than water, such as alcohols or cellosolves. 3. The transparent conductive material according to claim 1, wherein the dispersion stabilizer is a carboxylic acid or a sulfonic acid, or a water-soluble polymer compound such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyethylene glycol. Paint for film formation. 4. The aggregation inducer comprises an alkali metal ion,
The coating for forming a transparent conductive film according to claim 1, wherein the coating is at least one of ammonium ions. 5. The colloidal metal fine particles have an average particle size.
The paint for forming a transparent conductive film according to any one of claims 1 to 4, wherein the paint contains at least fine particles having a primary particle diameter of not more than 0.1 µm and not more than 0.005 µm. 6. The colloidal metal fine particles include gold, silver,
The transparent conductive film forming paint according to any one of claims 1 to 5, wherein the paint is at least one kind of colloidal metal fine particles of copper, aluminum, nickel, iron, tin, indium, and lead. 7. The coating for forming a transparent conductive film according to claim 1, wherein said colloidal metal fine particles are silver colloidal metal fine particles. 8. A method for producing a coating material for forming a transparent conductive film according to claim 1, wherein the method comprises the steps of: preparing a solution in which a metal salt is dissolved or a dispersion in which the metal salt is dispersed in a slurry. A dispersion comprising introducing a dispersion stabilizer and a reducing agent to form a dispersion of the colloidal metal fine particles having the dispersion stabilizer adsorbed on the surface thereof, and allowing the aggregation attractant to coexist in the dispersion; A method for producing a paint for forming a conductive film. 9. The reducing agent is a divalent iron salt, a divalent tin salt,
The method for producing a transparent conductive film forming paint according to claim 8, wherein the paint is at least one selected from a trivalent cerium salt and a trivalent titanium salt. 10. A transparent conductive film which is a continuous metal film which has been fused and has an uneven cross section, and a low refractive index transparent film coated on the transparent conductive film. A transparent conductive low-reflection film characterized by the above-mentioned. 11. The transparent conductive low-reflection film according to claim 10, wherein the maximum height of the projections of the metal film formed in the uneven shape from the substrate surface is 30 nm or less. 12. A method for producing a transparent conductive low-reflection film according to claim 10 or 11, wherein said production method comprises the steps of:
7. A coating for forming a transparent conductive film according to any one of (1) to (7) is applied and dried to form an agglomerated layer composed of agglomerated particles of metal fine particles. Heating at a predetermined heating temperature to melt the aggregated particles of the metal fine particles and to cure the low refractive index transparent film forming paint. 13. The method according to claim 12, wherein the heating temperature is 250 ° C. or lower. 14. The method according to claim 14, wherein the particle size of the aggregated metal fine particles is 0.3.
13. The method for producing a transparent conductive low-reflection film according to claim 12, wherein the thickness is not less than μm. 15. A display device with a transparent conductive low-reflection film, wherein the transparent conductive low-reflection film according to claim 10 is provided on the surface of a transparent base material.