JP5068298B2 - Transparent conductive film-forming coating liquid, transparent conductive film-coated substrate, and display device - Google Patents

Description

  The present invention relates to a coating liquid for forming a transparent conductive film, a substrate with a transparent conductive film, and a display device including the substrate as a front plate, and more specifically, antistatic properties, electromagnetic shielding properties, transparency, and reflection. Composition comprising a coating liquid capable of forming a substrate with a transparent conductive film excellent in prevention properties, the substrate with a transparent conductive film obtained using the coating liquid, and the substrate with a transparent conductive film The present invention relates to a display device including a front plate.

  Conventionally, transparent coatings having an antistatic function and an antireflection function on the surfaces thereof for the purpose of antistatic and antireflection of the surfaces of transparent substrates of display panels such as cathode ray tubes, fluorescent display tubes, liquid crystal display panels, etc. It was done to form.

  By the way, the influence of electromagnetic waves emitted from cathode ray tubes, etc. on the human body has recently become a problem, and in addition to conventional antistatic and antireflection, these electromagnetic waves and electromagnetic fields formed with the emission of electromagnetic waves are shielded. It is hoped to do.

One method of shielding these electromagnetic waves and the like is a method of forming a conductive film for shielding electromagnetic waves on the surface of a display panel such as a cathode ray tube. However, a conventional antistatic conductive film having a surface resistance of at least about 10 ⁷ Ω / □ is sufficient, whereas a conductive film for electromagnetic shielding is 10 ² to It was necessary to have a low surface resistance such as 10 ⁴ Ω / □.

When such a conductive film having a low surface resistance is formed by using a coating liquid containing a conductive oxide such as Sb-doped tin oxide and Sn-doped indium oxide, which has been conventionally used, It was necessary to make the film thickness thicker than the case. However, since the antireflection effect is not exhibited unless the film thickness of the conductive film is about 10 to 200 nm, conventional conductive oxides such as Sb-doped tin oxide and Sn-doped indium oxide have low surface resistance,
There was a problem that it was difficult to obtain a conductive film that was excellent in electromagnetic wave shielding properties and also in antireflection.

  Further, as one method for forming a conductive film having a low surface resistance, there is a method of forming a metal fine particle-containing film on the surface of a substrate using a coating liquid for forming a conductive film containing metal fine particles such as Ag. . In this method, a coating solution in which colloidal metal fine particles are dispersed in a polar solvent is used as a coating solution for forming a coating containing metal fine particles. In such a coating solution, in order to improve the dispersibility of the colloidal metal fine particles, the surface of the metal fine particles is surface-treated with an organic stabilizer such as polyvinyl alcohol, polyvinyl pyrrolidone or gelatin.

  However, a conductive coating formed using such a coating solution for forming a coating containing metal fine particles has a large intergranular resistance because the metal fine particles come into contact with each other through a stabilizer in the coating. Sometimes did not go down. For this reason, it is necessary to decompose and remove the stabilizer by baking at a high temperature of about 400 ° C. after film formation. However, if the baking is performed at a high temperature to decompose and remove the stabilizer, fusion and aggregation of metal fine particles occur. There has been a problem that the transparency and haze of the conductive film are lowered. In the case of a cathode ray tube or the like, there is a problem that the cathode ray tube deteriorates when exposed to a high temperature.

  Furthermore, in the conventional transparent conductive film containing fine metal particles such as Ag, the metal may be oxidized, particle growth may occur due to ionization, and corrosion may occur in some cases. As a result, there was a problem that the display device lacked reliability.

  In addition, since monodispersed fine particles are used in the conventional transparent conductive film, a sufficiently low resistance film can be obtained due to the influence of the matrix, the organic stabilizer remaining on the particle surface, the solvent, or the grain boundary resistance. If not, sufficient reproducibility may not be obtained. For this reason, for example, when the film thickness is increased in order to reduce the resistance of the film, there is a problem that transparency is lowered.

The present invention was made to solve the problems of the prior art as described above, 10 ²
It has a low surface resistance of about 10 ⁴ Ω / □ and forms a transparent conductive film with excellent antistatic properties, transparency, antireflection properties, antiglare properties and electromagnetic shielding properties, as well as excellent reliability. An object of the present invention is to provide a transparent conductive film-forming coating solution, a substrate with a transparent conductive film, and a display device including the substrate as a front plate.

A second coating liquid for forming a transparent conductive film according to the present invention comprises:
In a coating liquid for forming a transparent conductive film containing conductive fine particles and a polar solvent,
The conductive fine particles are rod-shaped conductive fine particles having an aspect ratio in the range of 2 to 200.

The third transparent conductive film forming coating liquid according to the present invention is a transparent conductive film forming coating liquid containing conductive fine particles and a polar solvent.
The conductive fine particles are a group of rod-shaped conductive fine particles in which conductive fine particles having a particle diameter of 1 to 100 nm are bonded to the surface of the rod-shaped fine particles,
And the aspect ratio of this rod-shaped electroconductive fine particle group exists in the range of 2-200, It is characterized by the above-mentioned.

  According to the present invention, the conductivity and electromagnetic shielding properties are excellent, the light transmittance can be controlled, the antireflection performance and the antiglare property, and the transparent conductive film that is highly reliable can be formed. A coating liquid for forming a conductive film can be obtained.

  Further, according to the present invention, a transparent conductive film having excellent electrical conductivity and electromagnetic shielding properties, light transmittance control, antireflection performance and antiglare property, and high reliability is formed. A substrate with a transparent conductive film can be obtained.

  If such a substrate with a transparent conductive film is used as a front plate of a display device, a display device having excellent electromagnetic shielding properties and antireflection properties and antiglare properties can be obtained.

It is the schematic which shows one aspect | mode of the chain | strand-shaped electroconductive fine particle group contained in the coating liquid for transparent conductive film formation concerning this invention. It is the schematic which shows another one aspect | mode of the chain | strand-shaped electroconductive fine particle group contained in the coating liquid for transparent conductive film formation concerning this invention. It is the schematic which shows another one aspect | mode of the chain | strand-shaped electroconductive fine particle group contained in the coating liquid for transparent conductive film formation concerning this invention. It is the schematic which shows the one aspect | mode of the rod-shaped electroconductive fine particles contained in the coating liquid for transparent conductive film formation concerning this invention. It is the schematic which shows another one aspect | mode of the rod-shaped electroconductive fine particles contained in the coating liquid for transparent conductive film formation which concerns on this invention. It is the schematic which shows the one aspect | mode of the rod-shaped electroconductive fine particle group contained in the coating liquid for transparent conductive film formation concerning this invention.

  Hereinafter, the present invention will be specifically described.

[First coating liquid for forming transparent conductive film]
First, the first coating liquid for forming a transparent conductive film according to the present invention will be described.

  The coating liquid for forming a transparent conductive film according to the present invention includes a chain conductive fine particle group and a polar solvent.

Chain conductive fine particle group The “chain conductive fine particle group” as used in the present invention is a chain having an average particle diameter of 1 to 100 nm, preferably 5 to 80 nm, as shown in FIG. Fine particles having a chain structure that are continuously bonded to each other.

  Such a chain conductive fine particle group is different from the case where primary particles are simply aggregated by interparticle attractive force or the like. Bonded through oxygen. Further, as shown in FIG. 2, the same or different components as the primary particles may be bonded to the contact portions of the particles called “neck”, and the primary particles may be bonded to each other in a plane. Such a chain-like conductive fine particle group may be linear, zigzag, or curved in an arc. Furthermore, as shown in FIG. 3, the ring-shaped conductive fine particle group may have a ring shape in which the ends are joined to each other.

  Since there is no intergranular resistance between the primary particles constituting such a chain conductive fine particle group, and neither an organic stabilizer nor a solvent can be present, a coating liquid containing the chain conductive fine particle group is applied. The resistance of the resulting film is reduced and a low resistance film is obtained.

  If the average primary particle size of the conductive fine particles exceeds 100 nm, it becomes difficult to form a chain conductive fine particle group, and even if it can be made, the number of contact points of the particles in the conductive layer is reduced, so that it has a low resistance value. It becomes difficult to obtain a conductive film. Furthermore, if the average primary particle size exceeds 100 nm, light absorption by the conductive fine particles increases, and the light transmittance of the coating may decrease or the haze of the coating may increase. If a coated substrate containing conductive fine particles having a thickness exceeding 100 nm is used, for example, as the front plate of a cathode ray tube, the brightness of the displayed image becomes insufficient, and thus the film thickness is reduced to obtain a certain transmittance. If the amount of the conductive fine particles is reduced, sufficient conductivity may not be obtained.

  In addition, when the average particle diameter of the conductive fine particles is less than 1 nm, the grain boundary resistance increases rapidly, so that a transparent conductive film having a low resistance value that can achieve the object of the present invention cannot be obtained. Sometimes. In addition, since the particles are small, the chain-like conductive fine particle group cannot be obtained, and the three-dimensionally aggregated particles tend to increase, and a conductive film having a low resistance value may not be obtained.

  The average length of such chain conductive fine particle groups is in the range of 2 to 200 nm, preferably 5 to 80 nm.

If the average length is less than 2 nm, the contact resistance increases and a low-resistance transparent conductive film may not be obtained. If the average length exceeds 200 nm, the formability of the transparent conductive film decreases, There is a problem in optical characteristics such as haze, and the appearance is further deteriorated.

  In the present invention, all the conductive fine particles may form the chain conductive fine particle group as described above, but at least a part of the conductive fine particles may form the chain conductive fine particle group. . In this case, the proportion of the chain conductive fine particle group is desirably contained in the conductive fine particles in an amount of 5% or more. When the proportion of the chain conductive fine particle group is less than 5%, the effect of reducing the resistance may be insufficient.

Such a chain conductive fine particle group includes Au, Ag, Pd, Cu, Ni, Ru, Rh, Sn, In,
Metals and / or metal hydroxides or metal oxides composed of one or more elements selected from Sb, Fe, Pt, Ti, Cr, Co, Al, Zn, Ta, Pb, Os, Ir, or different metal doped metals It is preferable to consist of an oxide and a mixture thereof.

  In the case where the chain conductive fine particle group is a metal fine particle composed of two or more kinds of elements, preferred metal combinations include Au-Cu, Ag-Pt, Ag-Pd, Au-Pd, Au-Rh, and Pt-Pd. , Pt-Rh, Fe-Ni, Ni-Pd, Fe-Co, Cu-Co, Ru-Ag, Au-Cu-Ag, Ag-Cu-Pt, Ag-Cu-Pd, Ag-Au-Pd, Au -Rh-Pd, Ag-Pt-Pd, Ag-Pt-Rh, Fe-Ni-Pd, Fe-Co-Pd, Cu-Co-Pd and the like. The two or more kinds of metals constituting the chain conductive fine particle group may be an alloy in a solid solution state or a eutectic body not in a solid solution state, and the alloy and the eutectic body coexist. May be. When the chain-like conductive fine particle group is composed of two or more kinds of metals, metal oxidation, ionization, or ion migration is suppressed, so that particle growth of the conductive fine particles after the coating is formed is suppressed. In addition, the chain conductive fine particle group composed of two or more kinds of metals has high corrosion resistance, and the decrease in conductivity and light transmittance is small, so that a transparent conductive film excellent in reliability should be formed. Can do.

Preferred examples of the case where the conductive fine particles are a metal oxide or a different metal doped metal oxide include, for example, tin oxide, indium oxide, Sn or F doped with tin oxide, Sb, F or P. Examples thereof include indium oxide, antimony oxide, and low-order titanium oxide.

  Such a chain conductive fine particle group is preferably obtained by subjecting a metal fine particle dispersed slurry or a metal hydroxide gel slurry to a heat treatment followed by a mechanical dispersion treatment.

Specifically, the chain conductive fine particle group is prepared by the following method.
(1) For example, in the case of a chain-like conductive fine particle group made of metal, it can be obtained by the following method.

  First, metal salt is reduced in an alcohol / water mixed solvent to prepare a metal fine particle-dispersed slurry having a primary particle size of 1 to 100 nm. At this time, a reducing agent is usually added. As the reducing agent, ferrous sulfate, trisodium citrate, tartaric acid, sodium borohydride, hydrazine, sodium hypophosphite and the like are used. In addition, when using 2 or more types of metal salts, 2 or more types of metal salts may be reduce | restored simultaneously, and after reducing each metal salt, you may mix.

It is desirable to remove ionic impurities from the obtained metal fine particle dispersed slurry. The method for removing ionic impurities is not particularly limited, and examples thereof include a method of treating with a cationic, anionic or amphoteric ion exchange resin. Although the ionic impurities vary depending on the amount of conductive fine particles in the coating solution, it is desirable that the ionic impurity has an ion concentration of 1000 ppm or less in the coating solution. If the amount of ionic impurities is 1000 ppm or less, the coating solution can have a high stability (long pot life), and moreover, the conductive fine particles are less likely to aggregate during the formation of the film, so that a smooth film can be formed. Can be formed.

  Next, the obtained metal fine particle dispersed slurry can be subjected to mechanical dispersion treatment. By this mechanical dispersion treatment, a sol in which the generated gel is peptized and the chain conductive fine particles are dispersed is obtained. Examples of such mechanical dispersion treatment include a sand mill method and an impact dispersion method, and the impact dispersion method is particularly preferably used. The impact dispersion method is a method in which slurry is collided with a wall at a high speed such as the speed of sound to be dispersed or pulverized, and is performed using an apparatus such as an Artimizer or Nanomizer, for example. In such a method, the bonds in the particles are not cut and the crystallinity is made amorphous, and the conductivity due to the generation of surface functional groups such as OH groups is not reduced, and the stably dispersed chain conductive material Since a fine particle group-dispersed sol is obtained, it is preferable.

  In addition, when performing a mechanical dispersion process, you may add a stabilizer. Specific examples of stabilizers include gelatin, polyvinyl alcohol, polyvinyl pyrrolidone, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, and citric acid. Examples thereof include acids and salts thereof, heterocyclic compounds, and mixtures thereof. The stabilizer used in the preparation of the conductive fine particles may be the same as or different from the stabilizer added to the coating solution described later, and the amount of stabilizer used is the CMC (critical micelle formation) of the stabilizer. It is desirable that the concentration is in the range of 5 to 50%, preferably 5 to 30%.

  If the amount of the stabilizer is less than 5% of the CMC, the amount of the stabilizer on the particle surface is small, so that non-chain particles linked in three dimensions may be formed, and the amount of the stabilizer is 50% of the CMC. If it exceeds, monodispersed particles increase without generating chain conductive fine particle groups, and the effect of lowering the resistance of the conductive layer due to the formation of conductive paths in the chain conductive fine particle groups may not be obtained.

 (2) In addition to the above, the chain conductive fine particle group composed of metal can be prepared by the following method.

  First, in the same manner as described above, a metal salt is reduced in an alcohol / water mixed solvent to prepare a metal fine particle-dispersed slurry having a primary particle size of 1 to 100 nm. At this time, a reducing agent is usually added. Examples of the reducing agent include the same as described above.

  Next, the prepared metal fine particle-dispersed slurry is subjected to heat treatment under pressure using a pressure vessel or the like (hereinafter, this treatment is referred to as autoclave treatment). Such autoclave treatment is usually performed at a temperature of about 100 to 250 ° C. At this time, a stabilizer may be added, and the kind and amount of the stabilizer are the same as described above. Further, when this heat treatment is performed, the generation ratio of the chain conductive fine particle group and the length of the chain conductive fine particle group can be controlled by the presence or absence of stirring of the metal fine particle dispersed slurry.

  After the autoclave treatment, the mechanical dispersion treatment as described above is performed.

Moreover, when performing an autoclave process, you may add a metal salt further. The metal salt used may be the same as or different from that used when preparing the metal fine particle dispersed slurry. When such a metal salt is added, the metal ion migrates to the neck portion during the heat treatment, and the particle bonding is changed from the point bonding to the surface bonding, and has a “neck” portion as shown in FIG. A group of chain conductive fine particles is obtained.
(3) Furthermore, the chain-like conductive fine particle group composed of a metal can be prepared by the following method.

First, a metal salt is reduced in an alcohol / water mixed solvent in the presence of a reducing agent and an organic stabilizer. At this time, examples of the reducing agent and the organic stabilizer used are the same as those described above. The organic stabilizer may be contained in an amount of 0.005 to 0.5 parts by weight, preferably 0.01 to 0.2 parts by weight with respect to 1 part by weight of the generated metal fine particles. The amount of organic stabilizer is 0.
When the amount is less than 005 parts by weight, sufficient dispersibility cannot be obtained, and when the amount exceeds 0.5 parts by weight,
The generation of chain-like conductive fine particle groups is small, the number of monodispersed particles is increased, and in the presence of excess organic stabilizers, aggregated particles may be formed, and the remaining organic stabilizers impede conductivity. There is.

Even in this method, as shown in FIG. 2, it is possible to have a chain conductive fine particle group having a “neck”.
(4) Further, when the chain conductive fine particle group is a metal oxide, it can be prepared as follows.

First, an alcohol solution containing a metal salt or metal alkoxide at a concentration of 0.1 to 5% by weight is heated and hydrolyzed. At this time, it may be added to warm water or an alkali as necessary. By such hydrolysis, a gel dispersion of a metal hydroxide having a primary particle diameter of 1 to 100 nm is prepared. Next, the gel dispersion is filtered and washed, and fired in air at a temperature of 200 to 800 ° C. to prepare conductive metal oxide fine particles.

Subsequently, this powder is dispersed in acidic or alkaline water and / or alcohol solvent to obtain a dispersion having a concentration of 10 to 50% by weight. If necessary, this dispersion is mechanically treated in the presence of an organic stabilizer as described above. Distributed processing. If necessary, an autoclave treatment may be performed as described above.
(5) Furthermore, the chain conductive fine particle group composed of the metal oxide, after filtering and washing the gel dispersion, after the metal hydroxide in the presence of an organic stabilizer as necessary. It can be obtained by autoclaving and further mechanical dispersion treatment. In this case, the ionic impurities may be removed by an ion exchange resin treatment as described above.

  The chain-like conductive fine particle group thus obtained is usually taken out from the resulting dispersion by a method such as centrifugation, washed with an acid as necessary, and then dispersed in a polar solvent described below. Is done. Moreover, the obtained dispersion liquid containing the chain | strand-shaped electroconductive fine particle group can also be used as a coating liquid as it is.

Preparation of coating liquid for forming transparent conductive film In the first coating liquid for forming a transparent conductive film according to the present invention, such a chain conductive fine particle group is dispersed in a polar solvent. Examples of polar solvents used in the present invention include water; alcohols such as methanol, ethanol, propanol, butanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, hexylene glycol; acetic acid methyl ester, ethyl acetate Esters such as esters; ethers such as diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether and diethylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, acetylacetone and acetoacetate And the like. These may be used singly or in combination of two or more.

Moreover, the coating liquid for forming a transparent conductive film according to the present invention may further contain a matrix forming component. The matrix-forming component acts as a binder for conductive fine particles when coating with the coating liquid for forming a transparent conductive film according to the present invention. As such a matrix forming component, at least one selected from a SiO ₂ precursor, a TiO ₂ precursor, a ZrO ₂ precursor or an organic polymer is preferably used, and among these, in particular, a SiO ₂ precursor,
Organic polymers are preferred. Specific examples of the SiO ₂ precursor include a polycondensate obtained by hydrolyzing an organosilicon compound such as alkoxysilane or a silicate polycondensate obtained by dealkalizing an aqueous alkali metal silicate solution. . Examples of the organic polymer include paint resins such as polyethylene, polyphenol, epoxy, polyamino acid, and polystyrene.

  In the coating liquid for forming a transparent conductive film according to the present invention, the conductive fine particles are desirably contained at a concentration of 0.05 to 5% by weight, preferably 0.1 to 2% by weight.

Further, the matrix-forming component is contained in an amount of 0.01 to
It may be contained in an amount of 0.9 part by weight, preferably 0.1 to 0.5 part by weight.

  In addition, the coating liquid for forming a transparent conductive film according to the present invention may contain an organic stabilizer in order to improve the dispersibility of the conductive fine particles. Specific examples of such organic stabilizers include gelatin, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, ethylenediaminetetraacetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, Examples thereof include polyvalent carboxylic acids such as fumaric acid, phthalic acid and citric acid and salts thereof, cellulose derivatives, heterocyclic compounds, surfactants, and mixtures thereof.

Such an organic stabilizer may be contained in an amount of 0.005 to 0.5 parts by weight, preferably 0.01 to 0.5 parts by weight, with respect to 1 part by weight of the conductive fine particles. The amount of organic stabilizer is 0.005
When the amount is less than parts by weight, sufficient dispersibility cannot be obtained, and when the amount exceeds 0.5 parts by weight, the conductivity may be hindered.

  Furthermore, the coating liquid for forming a transparent conductive film according to the present invention contains a dye, a coloring pigment or colored particles so that the visible light transmittance is constant in a wide wavelength range of visible light of the coating liquid. Also good.

  Known dyes, colored pigments or colored particles can be used, and specific examples thereof include fine-particle carbon, diazo dyes, titanium black, phthalocyanine pigments, and dioxazine pigments.

  When the coating liquid for forming a transparent conductive film contains a dye, a colored pigment or colored particles, the solid content concentration in the coating liquid for forming a transparent conductive film (total amount of conductive fine particles and additives such as dye and pigment) Is preferably 15% by weight or less, and preferably in the range of 0.15 to 5% by weight, from the viewpoint of the fluidity of the coating liquid and the dispersibility of particulate components such as conductive fine particles in the coating liquid.

  Furthermore, the coating liquid for forming a transparent conductive film according to the present invention includes alkali metal ions, ammonium ions and polyvalent metal ions present in the liquid, inorganic anions such as mineral acids, organic anions such as acetic acid and formic acid, etc. The total amount of ion concentration is desirably 1000 ppm or less. In particular, inorganic anions such as mineral acids may inhibit the stability and dispersibility of the chain conductive fine particle group, and it is desirable that the content in the coating solution is smaller. When the ion concentration is lowered, the dispersed state of the particulate component contained in the coating liquid for forming the transparent conductive film, particularly the conductive fine particles, is improved, and almost all the aggregated particles other than the chain conductive fine particle group are mostly collected. A coating solution not containing is obtained. Such a monodispersed state of the chain conductive fine particles in the coating liquid for forming a transparent conductive film is maintained even in the process of forming the transparent conductive film. For this reason, when a transparent conductive film is formed from a coating liquid for forming a transparent conductive film having a low ion concentration, only the chain conductive fine particle group is observed in the transparent conductive film.

  In addition, when a coating liquid for forming a transparent conductive film having a low ion concentration as described above is used, the group of chain conductive fine particles can be well dispersed and uniformly arranged in the transparent conductive film. Compared to the case where the conductive fine particles are aggregated in the conductive film, it is possible to provide a transparent conductive film having the same conductivity with fewer conductive fine particles. Further, it is possible to form a transparent conductive film free from point defects and thickness irregularities that are thought to be caused by aggregation of the chain conductive fine particle groups on the substrate.

  The method of deionization treatment for obtaining such a coating solution for forming a transparent conductive film having a low ion concentration is a method in which the ion concentration contained in the coating solution finally falls within the above range. If it is not particularly limited, for example, a dispersion prepared from a group of chain conductive fine particles, or a coating solution prepared from the dispersion is used as a cation exchange resin and / or an anion exchange resin or an amphoteric ion exchange resin. The method of making it contact, The method of wash | cleaning these liquids using an ultrafiltration membrane, etc. are mentioned.

[Second coating solution for forming transparent conductive film]
Next, the 2nd coating liquid for transparent conductive film formation concerning this invention is demonstrated.

The second coating liquid for forming a transparent conductive film according to the present invention contains rod-shaped conductive fine particles and the polar solvent.
Rod-shaped conductive fine particles The rod-shaped conductive fine particles have a rod shape as shown in FIG. 4, and the aspect ratio (particle length L / particle cross-sectional diameter D) of such particles is 2 to 200, preferably 2 to 50. It is in the range.

  The average length of the conductive fine particles is preferably in the range of 2 to 200 nm, preferably 5 to 100 nm.

  If the average length is less than 2 nm, the contact resistance increases and a low resistance transparent conductive film may not be obtained. On the other hand, when the length exceeds 200 nm, the formability of the transparent conductive film is lowered, there is a problem in optical properties such as haze, and the appearance is further deteriorated.

  Such rod-like conductive fine particles preferably have an average cross-sectional diameter of 1 to 100 nm, preferably 2 to 80 nm. When the average cross-sectional diameter exceeds 100 nm, the number of contact points of the particles in the conductive layer decreases, and it becomes difficult to obtain a transparent conductive film having a low resistance value. In addition, light absorption by the conductive fine particles may increase, and the light transmittance of the fine particle layer may decrease or haze may increase. For this reason, it is assumed that a coated substrate formed using a coating solution for forming a transparent conductive film containing rod-shaped conductive fine particles having an average cross-sectional diameter exceeding 100 nm is used as a front plate of a cathode ray tube, for example. However, the brightness of the display image is insufficient, so that sufficient conductivity may not be obtained if the film thickness is reduced in order to obtain a certain transmittance or if the amount of conductive fine particles is reduced. .

  In addition, since the rod-like conductive fine particles having a cross-sectional diameter of less than 1 nm have a sharply increased grain boundary resistance as in the case of the chain conductive fine particle group, it is impossible to obtain a transparent conductive film having a low resistance value. There is also. Further, rod-shaped particles having a cross-sectional diameter of less than 1 nm tend to aggregate three-dimensionally, and a transparent conductive film having a low resistance value may not be obtained.

Such rod-shaped conductive fine particles are Au, Ag, Pd, Cu, Ni, Ru, Rh, Sn, In,
Metals and / or metal hydroxides or metal oxides composed of one or more elements selected from Sb, Fe, Pt, Ti, Cr, Co, Al, Zn, Ta, Pb, Os, Ir, or different metal doped metals It is preferable to consist of an oxide and a mixture thereof.

  Further, as shown in FIG. 5, such rod-shaped conductive fine particles may have a ring shape in which tip portions are joined to each other.

  Such rod-like conductive fine particles can be obtained, for example, by the following method.

  When the conductive fine particles are metal oxides, rod-shaped metal oxide conductive fine particles can be prepared as follows.

  First, an alkali is added to an alcohol solution containing a metal salt or a metal alkoxide to prepare a metal oxide precipitate. Next, the precipitate is filtered and washed, then dispersed again in pure water, heat-treated in a pressure vessel (autoclave treatment), and then fired in air at a temperature of 200 to 800 ° C. to form a conductive metal oxide. Prepare microparticles.

  Subsequently, this powder is dispersed in acidic or alkaline water and / or alcohol solvent to obtain a dispersion having a concentration of 10 to 50% by weight. If necessary, this dispersion is mechanically treated in the presence of an organic stabilizer as described above. Distributed processing.

  In this case, the ionic impurities may be removed by an ion exchange resin treatment as described above.

  The rod-like conductive fine particles obtained in this way are usually taken out from the produced dispersion by centrifugation or the like, washed with an acid or the like as necessary, and then used after being dispersed in a polar solvent described later. Moreover, the obtained dispersion liquid containing rod-shaped electroconductive fine particles can also be used as a coating liquid as it is.

  The dispersion of rod-like conductive fine particles obtained in this way may be subjected to mechanical dispersion treatment in the same manner as the chain conductive fine particle group.

Preparation of coating liquid for forming transparent conductive film In the second coating liquid for forming a transparent conductive film according to the present invention, such rod-shaped conductive fine particles are dispersed in a polar solvent. Examples of the polar solvent to be used include the same ones as exemplified in the first coating liquid for forming a transparent conductive film.

  Further, the coating liquid for forming a transparent conductive film according to the present invention may further contain a matrix forming component as described above.

  In the coating liquid for forming a transparent conductive film according to the present invention, the rod-shaped conductive fine particles are desirably contained at a concentration of 0.05 to 5% by weight, preferably 0.1 to 2% by weight.

  The matrix-forming component may be contained in an amount of 0.01 to 0.9 parts by weight, preferably 0.1 to 0.5 parts by weight, per 1 part by weight of the rod-shaped conductive fine particles.

In addition, in the coating liquid for forming a transparent conductive film according to the present invention, in order to improve the dispersibility of the rod-shaped conductive fine particles, an organic stabilizer is added as in the first coating liquid for forming a transparent conductive film. It may be included. The organic stabilizer may be contained in an amount of 0.005 to 0.5 parts by weight, preferably 0.01 to 0.5 parts by weight, with respect to 1 part by weight of the conductive fine particles. The amount of organic stabilizer is 0.00
When the amount is less than 5 parts by weight, sufficient dispersibility cannot be obtained, and when it exceeds 0.5 parts by weight, the conductivity may be inhibited.

Furthermore, the coating liquid for forming a transparent conductive film according to the present invention contains a dye, a coloring pigment or colored particles so that the visible light transmittance is constant in a wide wavelength range of visible light of the coating liquid. Also good. When the coating liquid for forming a transparent conductive film contains a dye, a colored pigment or colored particles, the solid content concentration in the coating liquid for forming a transparent conductive film (total amount of conductive fine particles and additives such as dye and pigment) Is preferably 15% by weight or less, and preferably in the range of 0.15 to 5% by weight, from the viewpoint of the fluidity of the coating liquid and the dispersibility of particulate components such as conductive fine particles in the coating liquid.

  Furthermore, the coating liquid for forming a transparent conductive film according to the present invention includes alkali metal ions, ammonium ions and polyvalent metal ions present in the liquid, inorganic anions such as mineral acids, organic anions such as acetic acid and formic acid, etc. The total amount of ion concentration is desirably 1000 ppm or less. In particular, inorganic anions such as mineral acids may inhibit the stability and dispersibility of the rod-shaped conductive fine particles, and it is desirable that the content in the coating solution is smaller.

[Third coating solution for forming transparent conductive film]
First, the 3rd coating liquid for transparent conductive film formation concerning this invention is demonstrated.

  The coating liquid for forming a transparent conductive film according to the present invention contains rod-shaped conductive fine particle groups and a polar solvent.

Rod-shaped conductive fine particle group The “rod-shaped conductive fine particle group” referred to in the present invention is a conductive fine particle having a particle diameter in the range of 1 to 100 nm, preferably 5 to 80 nm on the surface of the rod-shaped fine particles as shown in FIG. Is a group of rod-shaped conductive fine particles joined together.

  The aspect ratio (particle length L / particle cross-sectional diameter D) of such particles is in the range of 2 to 200, preferably 2 to 50.

  Further, the average length of the rod-like conductive fine particle group is preferably in the range of 2 to 200 nm, preferably 5 to 100 nm.

  If the average length is less than 2 nm, the contact resistance increases and a low resistance transparent conductive film may not be obtained. On the other hand, when the length exceeds 200 nm, the formability of the transparent conductive film is lowered, there is a problem in optical properties such as haze, and the appearance is further deteriorated.

The conductive fine particles constituting such a group of rod-shaped conductive fine particles are Au, Ag, Pd, Cu, Ni.
, Ru, Rh, Sn, In, Sb, Fe, Pt, Ti, Cr, Co, Al, Zn, Ta, Pb, Os, Ir. It is preferably made of a metal oxide, a different metal doped metal oxide, or a mixture thereof.

  When the conductive fine particles are metal fine particles composed of two or more elements, preferred metal combinations include Au—Cu, Ag—Pt, Ag—Pd, Au—Pd, Au—Rh, Pt—Pd, and Pt. -Rh, Fe-Ni, Ni-Pd, Fe-Co, Cu-Co, Ru-Ag, Au-Cu-Ag, Ag-Cu-Pt, Ag-Cu-Pd, Ag-Au-Pd, Au-Rh -Pd, Ag-Pt-Pd, Ag-Pt-Rh, Fe-Ni-Pd, Fe-Co-Pd, Cu-Co-Pd and the like. The two or more kinds of metals constituting the conductive fine particles may be an alloy in a solid solution state or a eutectic that is not in a solid solution state, or the alloy and the eutectic may coexist. . When the conductive fine particles are composed of two or more kinds of metals, metal oxidation, ionization, or ion migration is suppressed, so that particle growth of the conductive fine particles after the coating is formed is suppressed. In addition, the conductive fine particles composed of two or more kinds of metals have high corrosion resistance and a small decrease in conductivity and light transmittance, so that a transparent conductive film with excellent reliability can be formed.

Preferred examples of the case where the conductive fine particles are a metal oxide or a different metal doped metal oxide include, for example, tin oxide, indium oxide, Sn or F doped with tin oxide, Sb, F or P. Examples thereof include indium oxide, antimony oxide, and low-order titanium oxide.

The rod-shaped fine particles are selected from Au, Ag, Pd, Cu, Ni, Ru, Rh, Sn, In, Sb, Fe, Pt, Ti, Cr, Co, Al, Zn, Ta, Pb, Os, Ir. It is preferably made of a metal, hydroxide, oxide, or metal-doped oxide composed of the above elements. The rod-shaped fine particles may be the rod-shaped conductive fine particles described above. The rod-shaped fine particles are not necessarily conductive, and may be non-conductive fine particles such as alumina, silica, and magnesia.

Specifically, the rod-shaped conductive fine particle group is prepared by the following method.
(1) For example, in the case of a rod-shaped conductive fine particle group made of metal, it can be obtained by the following method.

  First, fibrous metal oxide particles such as alumina are dispersed in an alcohol / water mixed solvent in advance, and after adding the metal salt of the metal to the dispersion, reduction is carried out on the surface of the fibrous oxide particles. A group of rod-like conductive fine particles bonded with conductive fine particles is obtained. The obtained conductive fine particle group slurry may be subjected to mechanical dispersion treatment.

 (2) In addition to the above, the rod-like conductive fine particle group can also be obtained by mixing the chain-like conductive fine particle group dispersion and the rod-like fine particle dispersion. The rod-shaped fine particles may be the rod-shaped conductive fine particles described above.

Preparation of Transparent Conductive Film Forming Coating Liquid In the third transparent conductive film forming coating liquid according to the present invention, such rod-shaped conductive fine particle groups are dispersed in a polar solvent. Examples of the polar solvent to be used include the same ones as exemplified in the first coating liquid for forming a transparent conductive film.

  Further, the coating liquid for forming a transparent conductive film according to the present invention may further contain a matrix forming component as described above.

  In the coating liquid for forming a transparent conductive film according to the present invention, the rod-shaped conductive fine particle group is desirably contained at a concentration of 0.05 to 5% by weight, preferably 0.1 to 2% by weight. .

In addition, the matrix forming component is 0.01 ~ per 1 part by weight of the rod-shaped conductive fine particle group.
It may be contained in an amount of 0.9 part by weight, preferably 0.1 to 0.5 part by weight.

Further, in the coating liquid for forming a transparent conductive film according to the present invention, in order to improve the dispersibility of the rod-shaped conductive fine particle group, an organic material is used in the same manner as the first and second coating films for forming a transparent conductive film. A system stabilizer may be included. The organic stabilizer is 0.005 with respect to 1 part by weight of the conductive fine particles.
˜0.5 parts by weight, preferably 0.01 to 0.5 parts by weight. When the amount of the organic stabilizer is less than 0.005 parts by weight, sufficient dispersibility cannot be obtained, and when it exceeds 0.5 parts by weight, the conductivity may be inhibited.

Furthermore, the coating liquid for forming a transparent conductive film according to the present invention contains a dye, a coloring pigment or colored particles so that the visible light transmittance is constant in a wide wavelength range of visible light of the coating liquid. Also good. When the coating liquid for forming a transparent conductive film contains a dye, a colored pigment or colored particles, the solid content concentration in the coating liquid for forming a transparent conductive film (total amount of conductive fine particles and additives such as dye and pigment) Is preferably 15% by weight or less, and preferably in the range of 0.15 to 5% by weight, from the viewpoint of the fluidity of the coating liquid and the dispersibility of particulate components such as conductive fine particles in the coating liquid.

  Furthermore, the coating liquid for forming a transparent conductive film according to the present invention includes alkali metal ions, ammonium ions and polyvalent metal ions present in the liquid, inorganic anions such as mineral acids, organic anions such as acetic acid and formic acid, etc. The total amount of ion concentration is desirably 1000 ppm or less. In particular, inorganic anions such as mineral acids may inhibit the stability and dispersibility of the rod-like conductive fine particle group, and it is desirable that the content in the coating solution is smaller.

[Base material with transparent conductive film]
Next, the substrate with a transparent conductive film according to the present invention will be specifically described.

The substrate with a transparent conductive film according to the present invention is
It consists of a base material, a transparent conductive film provided on the base material, and a transparent film provided on the transparent conductive film.

In the present invention, a known substrate can be used, and specific examples include films, sheets, and other molded bodies made of glass, plastics, ceramics, and the like.
Transparent conductive film The transparent conductive film is formed by applying and drying the first to third transparent conductive film forming coating liquids according to the present invention on a substrate.

  As a method for forming a transparent conductive film, for example, a coating liquid for forming a transparent conductive film is applied on a substrate by a dipping method, a spinner method, a spray method, a roll coater method, a flexographic printing method, or the like. Dry at a temperature ranging from room temperature to about 90 ° C.

  When the matrix-forming component as described above is contained in the coating liquid for forming a transparent conductive film, the matrix-forming component may be cured.

  Examples of the curing process include the following methods.

(A) Heat curing The coating film after drying is heated to cure the matrix component. The heat treatment temperature at this time is 100 ° C. or higher, preferably 150 to 300 ° C. If it is less than 100 degreeC, a matrix formation component may not fully harden | cure. Moreover, although the upper limit of heat processing temperature changes with kinds of base material, it should just be below the transition point of a base material.

(A) Electromagnetic curing After the coating process or the drying process, or during the drying process, the matrix component is cured by irradiating the coating film with an electromagnetic wave having a wavelength shorter than that of visible light. As the electromagnetic wave to be irradiated to promote the curing of the matrix forming component, ultraviolet rays, electron beams, X-rays, γ rays, etc. are used depending on the type of the matrix forming component. For example, in order to promote the curing of the ultraviolet curable matrix-forming component, for example, a high pressure mercury lamp having a maximum 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 source.
Ultraviolet rays with an energy amount of 00 mJ / cm ² or more are irradiated.

(C) Gas curing The matrix-forming component is cured by exposing the coating film to a gas atmosphere that promotes the curing reaction of the matrix-forming component after the coating step or the drying step or during the drying step. Among the matrix forming components, there is a matrix forming component whose curing is accelerated by an active gas such as ammonia. A transparent conductive film containing such a matrix forming component is used at a gas concentration of 100 to 100,000 ppm, preferably 1000 to 10,000 ppm. Curing of the matrix-forming component can be greatly accelerated by treating for 1 to 60 minutes under a certain curing-promoting gas atmosphere.

The film thickness of the transparent conductive film formed by the method as described above is preferably in the range of about 50 to 200 nm, and preferably in the range of 10 to 150 nm. A coated substrate can be obtained.
Transparent film In the base material with a transparent conductive film according to the present invention, a transparent film having a refractive index lower than that of the transparent conductive film is formed on such a transparent conductive film.

  The film thickness of the formed transparent film is 50 to 300 nm, preferably 80 to 200 nm.

  Such a transparent film is formed from, for example, inorganic oxides such as silica, titania and zirconia, and composite oxides thereof. In the present invention, a silica-based film made of a hydrolyzable polycondensate of a hydrolyzable organosilicon compound or a silicate polycondensate obtained by dealkalizing an alkali metal silicate aqueous solution is particularly preferable as the transparent film. The base material with a transparent conductive film on which such a transparent film is formed is excellent in antireflection performance.

  The transparent film may contain additives such as fine particles made of a low refractive index material such as magnesium fluoride, if necessary.

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

  The film thickness of the transparent coating is preferably in the range of 50 to 300 nm, and preferably in the range of 80 to 200 nm. When the film thickness is in such a range, excellent antireflection properties are exhibited.

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

  When the transparent film is formed by a wet thin film forming method, a conventionally known transparent film forming coating solution, for example, an inorganic oxide precursor such as silica, titania, zirconia, or a composite oxide precursor thereof is used as a transparent film forming component. It is possible to use a coating liquid for forming a transparent film contained as

  In the present invention, as a coating liquid for forming a transparent film, a hydrolytic polycondensate of a hydrolyzable organosilicon compound or a silica-based transparent film forming coating containing silicic acid obtained by dealkalizing an alkali metal silicate aqueous solution In particular, a coating liquid for forming a silica-based transparent film containing a hydrolyzed polycondensate of alkoxysilane represented by the following general formula [1] is preferable. A silica-based film formed from such a coating solution has a refractive index smaller than that of the transparent conductive film, and the obtained substrate with a transparent film is excellent in antireflection properties.

R _a Si (OR ′) _4-a [1]
(In the formula, R is a vinyl group, an aryl group, an acrylic 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 acrylic group, or an alkyl group having 1 to 8 carbon atoms. An alkyl group, —C ₂ H ₄ OC _n H _{2n + 1} (n = 1 to 4) or a hydrogen atom, and a is an integer of 1 to 3)
Such alkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraoctylsilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, methyltriisopropoxysilane, Examples include vinyltrimethoxysilane, phenyltrimethoxysilane, and dimethyldimethoxysilane.

When one or more of the above alkoxysilanes are hydrolyzed in the presence of an acid catalyst in, for example, a water-alcohol mixed solvent, a coating solution for forming a transparent film containing a hydrolysis polycondensate of alkoxysilane is obtained. . It is preferable that the density | concentration of the film formation component contained in such a coating liquid is 0.5 to 20 weight% in conversion of an oxide. The coating liquid for forming a transparent film used in the present invention is subjected to deionization treatment as in the case of the coating liquid for forming a transparent conductive film, and the ion concentration of the transparent conductive coating liquid is determined to form the transparent conductive film. You may reduce to the same level as the density | concentration in the application liquid.

  Furthermore, the coating liquid for forming a transparent film used in the present invention contains fine particles composed of a low refractive index material such as magnesium fluoride, and a small amount of conductivity that does not impair the transparency and antireflection performance of the transparent film. Additives such as fine particles, dyes, coloring pigments, and fine particle carbon may be contained.

  In the present invention, a film formed by applying such a coating solution for forming a transparent film is dried at a temperature of 150 ° C. or higher, heated at 150 ° C. or higher after drying, or an uncured film from visible light. Alternatively, a treatment such as irradiation with an electromagnetic wave such as ultraviolet rays having a short wavelength, electron beam, X-ray, or γ-ray, or exposure to an active gas atmosphere such as ammonia may be performed. When the treatment is performed in this manner, curing of the film-forming component is promoted, and the hardness of the obtained transparent film can be increased. Moreover, when performing the said hardening process, when apply | coating the coating liquid for transparent film formation, it is preferable to apply | coat the coating liquid for transparent film formation, hold | maintaining a transparent conductive film at about 40-90 degreeC. While holding the transparent conductive film at about 40 to 90 ° C., by applying a coating solution for forming a transparent film on the transparent conductive film, ring-shaped irregularities are formed on the surface of the transparent film, and the glare A substrate with a transparent coating with a small amount of antiglare can be obtained.

[Display device]
The substrate with a transparent conductive film according to the present invention has a surface resistance in the range of 102 to 104 Ω / □ necessary for electromagnetic shielding, and has sufficient antireflection performance and antiglare properties in the visible light region and the near infrared region. The transparent conductive film-coated substrate having a property is suitably used as a front plate of a display device.

  The display device according to the present invention is a device that electrically displays an image such as a cathode ray tube (CRT), a fluorescent display tube (FIP), a plasma display (PDP), a liquid crystal display (LCD), and the like. A front plate made of a substrate with a transparent conductive film.

  When a conventional display device having a front plate is operated, an image is displayed on the front plate and electromagnetic waves are emitted from the front plate at the same time. This electromagnetic wave affects the human body of the observer. In the apparatus, since the front plate is composed of a substrate with a transparent conductive film having a surface resistance of 102 to 104 Ω / □, it effectively shields such electromagnetic waves and electromagnetic fields generated by the emission of the electromagnetic waves. can do.

In addition, when reflected light is generated on the front plate of the display device, the display image is difficult to see due to the reflected light. In the display device according to the present invention, the front plate has sufficient antireflection performance in the visible light region and the near infrared region. And since it is comprised with the base material with a transparent conductive film which has anti-glare property, such reflected light can be prevented effectively.

  Furthermore, the front plate of the cathode ray tube is composed of a substrate with a transparent conductive film according to the present invention, and a small amount of at least one of the transparent conductive film and the transparent film formed thereon is included in the transparent conductive film. When dyes or pigments are contained, these dyes or pigments each absorb light having a specific wavelength, thereby improving the contrast of a display image broadcast from the cathode ray tube.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
[Production Example]
a) Preparation of conductive fine particle dispersion The conductive fine particle dispersion used in this example and comparative examples are shown in Table 1.
Chain conductive fine particles (P-1)
First, an aqueous solution was prepared by adding silver nitrate and an aqueous palladium nitrate solution to 100 g of pure water in advance so that the concentration was 10% by weight in terms of metal and the metal species of the composite metal was in the weight ratio shown in Table 1. In this aqueous solution, an aqueous solution containing trisodium citrate (an organic stabilizer and a reducing agent) in an amount of 0.01 part by weight per part by weight of the composite metal, the total number of moles of silver nitrate and palladium nitrate, etc. A mixed solution mixed with a molar number of ferrous sulfate (reducing agent) aqueous solution was added and stirred for 1 hour in a nitrogen atmosphere to obtain a dispersion of composite metal fine particles.

The obtained dispersion is separated by a centrifuge and then acid-washed with HCl having a concentration of 1% by weight, and polyacrylic acid is added so as to be 0.0128 parts by weight per 1 part by weight of the composite metal and dispersed in pure water. Thus, a dispersion having a concentration shown in Table 1 was prepared. Subsequently, the obtained dispersion was treated with a nanomizer system (Nanomizer Co., Ltd .: LA-33-S) to obtain a dispersion of chain conductive fine particles (P-1).
Chain conductive fine particles (P-2)
After adding chloroplatinic acid to 100 g of pure water in advance, adding an acetone solution of palladium acetate so that the concentration in terms of metal is 10% by weight and the metal species of the composite metal is in the weight ratio of Table 1, Trisodium citrate having the same number of moles as the total number of moles of chloroplatinic acid and palladium acetate was added, and the mixture was stirred for 1 hour in a nitrogen atmosphere to obtain a composite metal fine particle dispersion.

The obtained dispersion is separated by a centrifuge and then acid-washed with HCl having a concentration of 1% by weight, and polyacrylic acid is added so as to be 0.0128 parts by weight per 1 part by weight of the composite metal and dispersed in pure water. Thus, a dispersion having a concentration shown in Table 1 was prepared. Subsequently, the obtained dispersion was subjected to a nanomizer system treatment to obtain a dispersion of chain conductive fine particles (P-2).
Chain conductive fine particles (P-3)
The prepared dispersion of conductive fine particles (P-1) was placed in an autoclave in a nitrogen atmosphere, 15
After stirring for 1 hour at 0 ° C. and 10.0 Kg / cm ² , treatment was performed using the nanomizer system to obtain a dispersion of chain conductive fine particles (P-3).
Chain conductive fine particles (P-4)
To the prepared dispersion of conductive fine particles (P-1), an aqueous silver nitrate solution is added so that the metal species of the composite metal is in the weight ratio shown in Table 1, and an aqueous ferrous sulfate solution having an equimolar number of silver nitrate is added. The mixture was stirred for 1 hour in a nitrogen atmosphere to obtain a dispersion of composite metal fine particles. The obtained dispersion was separated by a centrifuge, washed with water and dispersed in pure water to prepare dispersions having the concentrations shown in Table 1. Subsequently, the obtained dispersion was processed with a nanomizer system to obtain a dispersion of chain conductive fine particles (P-4).
Rod-shaped conductive fine particles (P-5)
To 100 g of pure water, fibrous alumina fine particles having an average length of 50 nm and an average cross-sectional diameter of 10 nm are added in advance so as to have a weight ratio shown in Table 1 as a chain inorganic oxide. An aqueous solution to which silver nitrate and an aqueous palladium nitrate solution were added so as to have a weight ratio shown in Table 1 was prepared. In this aqueous solution, an aqueous solution containing trisodium citrate (an organic stabilizer and a reducing agent) in an amount of 0.01 part by weight per 1 part by weight of the composite metal, the concentration in terms of metal is 10% by weight, A mixed solution in which the total number of moles of silver nitrate and palladium nitrate and an equimolar number of ferrous sulfate (reducing agent) aqueous solution was mixed was added and stirred for 1 hour in a nitrogen atmosphere to obtain a dispersion of composite metal fine particles.

The obtained dispersion is separated by a centrifuge and then acid-washed with HCl having a concentration of 1% by weight, and polyacrylic acid is added so as to be 0.0128 parts by weight per 1 part by weight of the composite metal and dispersed in pure water. Thus, a dispersion having a concentration shown in Table 1 was prepared. Subsequently, the obtained dispersion was treated with a nanomizer system (Nanomizer Co., Ltd .: LA-33-S) to obtain a dispersion of rod-shaped conductive fine particle groups (P-5).
Rod-shaped conductive fine particles (P-6)
The dispersion of composite alumina fine particles (P-1) is mixed with the dispersion of fibrous alumina fine particles used in the conductive fine particles (P-5) so that the weight ratio shown in Table 1 is satisfied, and a nanomizer system is used. Thus, a dispersion of rod-shaped composite metal fine particles (P-6) was obtained.
Rod-shaped conductive fine particles (P-7)
To 100 g of pure water, indium nitrate and tin fluoride are added in advance so that the metal conversion becomes 10% by weight and the metal species of the composite metal is in the weight ratio shown in Table 1, and 10% by weight of potassium hydroxide is added thereto. A composite metal particle precipitate was prepared. The precipitate of the composite metal particles was washed with water, pure water was added so that the metal equivalent would be 10% by weight, this was treated in an autoclave at 200 ° C. for 2 hours, and then dried at 100 ° C. Next, after the dried composite metal particles are baked at 550 ° C. for 2 hours in a nitrogen stream, pure water and acetylacetone (organic dispersant) are added, and the mixture is treated with a sand mill and a nanomizer system to form rod-shaped composite metal fine particles ( A dispersion of P-7) was obtained.
Monodispersed conductive fine particles (P-8)
An aqueous solution in which silver nitrate and an aqueous palladium nitrate solution were added to 100 g of pure water in advance so that the concentration in terms of metal was 10% by weight and the metal species of the composite metal was in the weight ratio shown in Table 1 was prepared. In this aqueous solution, an aqueous solution containing trisodium citrate (an organic stabilizer and a reducing agent) in an amount of 0.01 part by weight per part by weight of the composite metal, the total number of moles of silver nitrate and palladium nitrate, etc. A mixed solution mixed with a molar number of ferrous sulfate (reducing agent) aqueous solution was added and stirred for 1 hour in a nitrogen atmosphere to obtain a dispersion of composite metal fine particles.

The obtained dispersion was separated by a centrifugal separator, washed with water and dispersed in pure water to prepare monodisperse conductive fine particles (P-8) having the concentrations shown in Table 1.
Conductive fine particles (P-9)
An aqueous solution in which silver nitrate and an aqueous palladium nitrate solution were added to 100 g of pure water in advance so that the concentration in terms of metal was 10% by weight and the metal species of the composite metal was in the weight ratio shown in Table 1 was prepared. This aqueous solution contains an aqueous solution containing trisodium citrate (an organic stabilizer and a reducing agent) in an amount of 0.01 part by weight per part by weight of the composite metal, and the total number of moles of silver nitrate and palladium nitrate. A mixed solution prepared by mixing a 3-fold mole number of ferrous sulfate (reducing agent) aqueous solution was added and stirred for 1 hour in a nitrogen atmosphere to obtain a dispersion of composite metal fine particles. The obtained dispersion is separated by a centrifuge and then acid-washed with HCl having a concentration of 1% by weight, and polyacrylic acid is added so as to be 0.0128 parts by weight per 1 part by weight of the composite metal and dispersed in pure water. Thus, a dispersion having a concentration shown in Table 1 was prepared. Next, the obtained dispersion was pulverized with a nanomizer to obtain a dispersion of composite metal fine particles (P-9). The shape of the obtained composite metal fine particles (P-9) was a chain of conductive fine particles.
Conductive fine particles (P-10)
An aqueous solution in which silver nitrate and an aqueous palladium nitrate solution were added to 100 g of pure water in advance so that the concentration in terms of metal was 10% by weight and the metal species of the composite metal was in the weight ratio shown in Table 1 was prepared. This aqueous solution contains an aqueous solution containing trisodium citrate (an organic stabilizer and a reducing agent) in an amount of 0.01 part by weight per part by weight of the composite metal, and the total number of moles of silver nitrate and palladium nitrate. A mixed solution prepared by mixing 3 times mole number of ferrous sulfate (reducing agent) aqueous solution was added and stirred for 1 hour in a nitrogen atmosphere to obtain a dispersion of fine composite metal particles. The obtained dispersion is separated by a centrifuge and then acid-washed with HCl having a concentration of 1% by weight. Polyacrylic acid is added to 0.03 part by weight per part by weight of the composite metal, and purified water is added. Dispersions having the concentrations shown in Table 1 were prepared by dispersing. Next, the obtained dispersion was pulverized with a nanomizer to obtain a dispersion of composite metal fine particles (P-10). The shape of the obtained composite metal fine particles (P-10) was a chain conductive fine particle group.
Conductive fine particles (P-11)
An aqueous solution in which silver nitrate and an aqueous palladium nitrate solution were added to 100 g of pure water in advance so that the concentration in terms of metal was 10% by weight and the metal species of the composite metal was in the weight ratio shown in Table 1 was prepared. This aqueous solution contains an aqueous solution containing trisodium citrate (an organic stabilizer and a reducing agent) in an amount of 0.01 part by weight per part by weight of the composite metal, and the total number of moles of silver nitrate and palladium nitrate. A mixed solution prepared by mixing a 3-fold mole number of ferrous sulfate (reducing agent) aqueous solution was added and stirred for 1 hour in a nitrogen atmosphere to obtain a dispersion of composite metal fine particles. The obtained dispersion is separated by a centrifuge and then acid-washed with HCl having a concentration of 1% by weight, and polyacrylic acid is added to 0.20 part by weight per part by weight of the composite metal. Dispersions having the concentrations shown in Table 1 were prepared by dispersing. Next, the obtained dispersion was pulverized with a nanomizer to obtain a dispersion of composite metal fine particles (P-11). The obtained composite metal fine particles (P-11) were agglomerated particles.

Conductive oxide fine particles (P-12)
To 100 g of pure water, indium nitrate and tin fluoride are added in advance so that the metal conversion becomes 10% by weight and the metal species of the composite metal is in the weight ratio shown in Table 1, and 10% by weight of potassium hydroxide is added thereto. A composite metal particle precipitate was prepared. After the precipitate of the composite metal particles is washed with water, pure water is added so as to be 10% by weight in terms of metal, pure water and acetylacetone (organic dispersant) are added thereto, and the mixture is treated with a sand mill and a nanomizer system. A dispersion of monodispersed composite metal fine particles (P-12) was obtained.

Conductive carbon fine particles (P-13)
Conductive fine particle (P-13) dispersion liquid was prepared by adding conductive carbon fine particles (manufactured by Mitsubishi Chemical Corporation: MA-100) as a colorant to 100 g of pure water so as to have the concentration shown in Table 1.

In addition, the primary particle of the conductive fine particles of the present invention, the observation of the chain shape and the rod shape, the measurement of the particle diameter, the particle length, etc. are measured using 100 particles using a scanning electron microscope (JEOL Ltd .: JMS5300). Observed about.

  The aspect ratio was expressed as L / D, where L is the particle length, and D is the cross-sectional diameter of the particle. The aspect ratio of the chain conductive fine particle group was such that the particle length was L and the primary particle diameter was the cross-sectional diameter D of the particles.

b) Preparation of matrix-forming component liquid (M ) 50 g of normal ethyl silicate (SiO 2: 28% by weight), 194.6 g of ethanol, concentrated nitric acid 1.4
A liquid (M) containing a matrix forming component having a SiO2 concentration of 5% by weight was prepared by stirring a mixed solution of g and 34 g of pure water at room temperature for 5 hours.
c) Preparation of coating liquid for forming transparent conductive film (A) liquid, water, t-butanol, butyl containing dispersion liquids (P-1) to (P-13) shown in Table 1 and the above matrix-forming components Coating solutions (C-1) to (C-14) for forming transparent conductive films shown in Table 2 were prepared using cellosolve, citric acid and N-methyl-2-pyrrolidone.

d) Preparation of coating solution for forming transparent film (B-1) Mixing ethanol / butanol / diacetone alcohol / isopropanol (2: 1: 1: 5 weight mixing ratio) with the above-mentioned matrix-forming component (A) solution A solvent was added to prepare a coating solution (B-1) for forming a transparent film having a SiO2 concentration of 1% by weight.

In addition, the coating liquid for forming a conductive film and the coating liquid for forming a transparent film used in the present invention are deionized with an amphoteric ion exchange resin (Diaion SMNUPB, manufactured by Mitsubishi Chemical Corporation). The ion concentration was adjusted.

In addition, the alkali metal ion concentration and alkaline earth metal ion concentration in the coating solution are measured by atomic absorption, the other metal ion concentrations are measured by emission spectroscopy, and the ion concentrations of ammonium ions and anions are measured by ion chromatography. Measured by the method.

[Examples 1 to 9]
Manufacture of panel glass with transparent conductive film The above-mentioned coating liquid for forming transparent conductive film (C-1) under the condition of 100 rpm and 90 seconds by a spinner method while maintaining the surface of the panel glass (14 ") for CRT at 40 ° C. ) To (C-9) were applied and dried.

  Next, on the transparent conductive film thus formed, the coating liquid for forming a transparent film (B-1) was similarly applied and dried under the conditions of 100 rpm and 90 seconds by the spinner method. Firing was performed under the conditions shown to obtain a substrate with a transparent conductive film.

  The surface resistance of these substrates with transparent conductive films was measured with a surface resistance meter (Mitsubishi Yuka Co., Ltd .: LORESTA), and haze was measured with a haze computer (Nippon Denshoku Co., Ltd .: 3000A). . The reflectivity was measured using a reflectometer (manufactured by Otsuka Electronics Co., Ltd .: MCPD-2000), and the reflectivity was the reflectivity at the lowest reflectivity in the wavelength range of 400 to 700 nm.

  The results are shown in Table 3.

[Comparative Examples 1-5]
Manufacture of panel glass with transparent conductive film The above-mentioned coating liquid for forming a transparent conductive film (C-10) under the conditions of 100 rpm and 90 seconds by a spinner method while maintaining the surface of the panel glass (14 ") for CRT at 40 ° C. ) To (C-14) were applied and dried.

  Next, on the transparent conductive film thus formed, the coating liquid for forming a transparent film (B-1) was similarly applied and dried under the conditions of 100 rpm and 90 seconds by the spinner method. Firing was performed under the conditions shown to obtain a substrate with a transparent conductive film.

  The surface resistance of these substrates with transparent conductive films was measured with a surface resistance meter (Mitsubishi Yuka Co., Ltd .: LORESTA), and haze was measured with a haze computer (Nippon Denshoku Co., Ltd .: 3000A). . The reflectivity was measured using a reflectometer (manufactured by Otsuka Electronics Co., Ltd .: MCPD-2000), and the reflectivity was the reflectivity at the lowest reflectivity in the wavelength range of 400 to 700 nm.

  The results are shown in Table 3.

Claims (12)

  In a coating liquid for forming a transparent conductive film containing a conductive fine particle and a polar solvent, the conductive fine particle has an aspect ratio in the range of 2 to 200 and an average length in the range of 5 to 100 nm. A coating liquid for forming a transparent conductive film, characterized in that The rod-like conductive fine particles are Au, Ag, Pd, Cu, Ni, Ru, Rh, Sn, In, Sb, Fe.
, Pt, Ti, Cr, Co, Al, Zn, Ta, Pb, Os, Ir or a metal and / or metal hydroxide or metal oxide, or a heterogeneous metal-doped metal oxide. The coating liquid for forming a transparent conductive film according to claim 1.   In a coating liquid for forming a transparent conductive film containing conductive fine particles and a polar solvent, the conductive fine particles are a group of rod-shaped conductive fine particles in which conductive fine particles having a particle diameter in the range of 1 to 100 nm are bonded to the surface of the rod-shaped fine particles. And a coating liquid for forming a transparent conductive film, wherein the rod-like conductive fine particle group has an aspect ratio in the range of 2 to 200 and an average length in the range of 5 to 100 nm. The conductive fine particles bonded to the surface of the rod-shaped fine particles are Au, Ag, Pd, Cu, Ni, Ru, Rh.
, Sn, In, Sb, Fe, Pt, Ti, Cr, Co, Al, Zn, Ta, Pb, Os, Ir, a metal, hydroxide, oxide, or metal-doped oxide composed of one or more elements The coating liquid for forming a transparent conductive film according to claim 3, wherein the coating liquid is made of a material. The rod-shaped fine particles are selected from Au, Ag, Pd, Cu, Ni, Ru, Rh, Sn, In, Sb, Fe, Pt, Ti, Cr, Co, Al, Zn, Ta, Pb, Os, Ir. The coating liquid for forming a transparent conductive film according to claim 3 or 4, comprising a metal, hydroxide, oxide, or metal-doped oxide comprising the above elements.   The rod-shaped conductive fine particles are prepared by adding an alkali to an alcohol solution containing a metal salt or a metal alkoxide to prepare a metal oxide precipitate, and then filtering and washing the precipitate, and then redispersing in pure water to obtain a pressure vessel After heat treatment (autoclave treatment) in the air, it is fired in air at a temperature of 200 to 800 ° C., and the obtained powder is dispersed in alkaline water and / or an alcohol solvent and mechanically dispersed. The coating liquid for forming a transparent conductive film according to any one of claims 1 to 5, wherein the liquid coating liquid is obtained.   The coating liquid for forming a transparent conductive film according to any one of claims 1 to 6, further comprising an organic stabilizer.   Furthermore, a matrix forming component is included, The coating liquid for transparent conductive film formation in any one of Claims 1-7 characterized by the above-mentioned. The matrix forming component SiO ₂ precursor, TiO ₂ precursor, a transparent conductive film-forming coating liquid according to claim 8, characterized in that it consists of at least one selected from ZrO ₂ precursors or organic polymers.   Furthermore, the coating liquid for transparent conductive film formation in any one of Claims 1-9 containing dye, a color pigment, or a colored particle.   A substrate, a transparent conductive film formed by applying the coating liquid for forming a transparent conductive film according to any one of claims 1 to 10 on the substrate, the transparent conductive film, and A substrate with a transparent conductive film, comprising: a transparent film having a refractive index lower than that of the transparent conductive film.   A display device comprising a front plate comprising the substrate with a transparent conductive coating according to claim 11, wherein the transparent coating is formed on the outer surface of the front plate.

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