Base material with transparent conductive covering, its manufacture, and display device with this base material

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical Field of Invention]

The present invention relates to a base material with a transparent conductive coating and a display device provided with the base material as a front plate. More specifically, a base material having a transparent conductive coating having excellent antireflection performance and an electromagnetic shielding effect. The present invention relates to a manufacturing method and a display device provided with a front plate made of such a substrate with a transparent conductive coating.

【0002】

[Technical Background of the Invention]

Conventionally, for the purpose of antistatic and antireflection on the surface of a transparent base material such as a display panel such as a cathode ray tube, a fluorescent display tube, or a liquid crystal display board, a transparent coating having an antistatic function and an antireflection function is provided on these surfaces. Is being formed.

【0003】

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

【0004】

For example, Japanese Patent Application Laid-Open No. 5-290634 states that a transparent conductive film is formed on a base material, and then a transparent film having a refractive index lower than that of the transparent conductive film is formed on the transparent conductive film. A method for producing a base material with a conductive coating and a base material with an antistatic / antireflection film obtained by such a method are disclosed. Of these, the transparent conductive film is formed from a coating liquid containing fine powder of tin oxide doped with antimony as a conductive substance.

【0005】

Further, in Japanese Patent Application Laid-Open No. 5-341103, a conductive coating film containing a conductive substance is formed on a base material, and an antireflection film derived from a specific silicon compound is formed on the conductive coating film. A substrate with a conductive film having excellent antireflection and antistatic properties thus obtained is disclosed. Further, in this publication, as the conductive substance, an electrolyte composed of perchlorates such as alkali metal, alkaline earth metal and transition metal, and inorganic compounds such as thiosian salt, trifluoromethyl sulfate and halogenated salt, Alternatively, transparent conductive inorganic oxide fine particles such as tin oxide-based fine particles and indium oxide-based fine particles are exemplified, but it is described that conductive inorganic oxide fine particles are preferable.

【0006】

By the way, recently, the influence of electromagnetic waves emitted from a cathode ray tube (CRT) or the like on the human body has become a problem, and in addition to the conventional antistatic and antireflection functions, these electromagnetic waves and electromagnetic waves are formed. It is desired to shield the electromagnetic field.

【0007】

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

【0008】

However, conventional conductive coatings for antistatic purposes only have at least 10⁵While it is sufficient to have a surface resistance of about Ω / , the conductive coating for electromagnetic shielding is 10²~10⁴It is necessary to have a low surface resistance such as Ω / .

【0009】

When an attempt is made to form a conductive film having such a low surface resistance using a coating liquid containing a conductive oxide such as conventional Sb-doped tin oxide or Sn-doped indium oxide, it is possible to form a conductive film having a lower surface resistance than that of a conventional antistatic film. Also, the film thickness must be increased.

【0010】

Therefore, a coating liquid containing such Sb-doped tin oxide or Sn-doped indium oxide is used as a conductive substance on the surface of the transparent substrate to form a conductive film exhibiting an electromagnetic shielding effect, and further, low refractive index is formed on the conductive film. When an attempt is made to form a transparent laminated film having electromagnetic shielding and antireflection functions by laminating a film having a high refractive index, the conductive film formed from the coating liquid as described above has a high refractive index of 1.5 to 2.0. Therefore, in order to design the optical film thickness of the conductive film so as to exhibit the antireflection effect together with the low refractive index film laminated on the film, the actual conductive film is actually used. The film thickness should be about 100 to 200 nm. However, with this film thickness, it is not possible to obtain sufficient surface resistance to exert the electromagnetic shielding effect.

【0011】

Also in JP-A-5-290634 and JP-A-5-341103 described above, the film thickness of the conductive film is as thin as, for example, about 0.1 μM (100 nm), and therefore the surface resistance of the laminated film is 10.⁷It is about Ω / , and it is hard to say that it has an electromagnetic shielding function.

【0012】

[Purpose of Invention]

The present invention has been made in view of the above circumstances, has excellent antireflection performance, and has 10²~10⁴A display device equipped with a transparent conductive coating base material having a surface resistance of Ω / and excellent electromagnetic shielding effect, a manufacturing method thereof, and a front plate made of such a transparent conductive coating base material. It is intended to be provided.

【0013】

[Summary of Invention]

In the base material with a transparent conductive coating according to the present invention, a transparent conductive fine particle layer composed of metal fine particles having an average particle diameter of 2 to 200 nm is formed on the base material, and the fine particle layer has a higher refractive index than the fine particle layer. It is characterized by the formation of a low transparent film.

【0014】

In the method for producing a base material with a transparent conductive coating according to the present invention, a coating liquid for forming a transparent conductive fine particle layer obtained by dispersing metal fine particles having an average particle size of 2 to 200 nm in water and / or an organic solvent is used. It is characterized in that a transparent conductive fine particle layer is formed by coating and drying on a substrate, and then a transparent film having a refractive index lower than that of the fine particle layer is formed on the fine particle layer.

【0015】

The display device according to the present invention is characterized by including a front plate made of a base material with a transparent conductive coating as described above.

【0016】

[Specific Description of the Invention]

Substrate with transparent conductive coating First, the substrate with a transparent conductive coating according to the present invention will be specifically described.

【0017】

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

【0018】

The metal fine particles used in the present invention are not particularly limited as long as the average particle size is within the above range. For example, Au, Ag, Pt, Pd, Rh, Cu, Fe, Ni, Co, Sn, In, Ti, Examples include metal fine particles such as Al and Ta.

【0019】

When the average particle size of these metal fine particles exceeds 200 nm, the absorption of light by the metal becomes large, which lowers the light transmittance of the particle layer and at the same time increases the haze. When such a coated base material is used, for example, as a front plate of a cathode ray tube, the resolution of the displayed image is lowered.

【0020】

Further, when the average particle size of these metal fine particles is less than 2 nm, the surface resistance of the particle layer rapidly increases, so that a film having a low resistance value that can achieve the object of the present invention cannot be obtained.

【0021】

In the present invention, the transparent conductive fine particle layer may be composed of only metal fine particles having an average particle size within the above range, and in addition to such metal fine particles, a small amount of conductive fine particles other than the metal fine particles. Additives such as organic or inorganic dyes or pigments may be contained.

【0022】

As the conductive fine particles other than the metal fine particles, known transparent conductive inorganic oxide fine particles or colored conductive fine particles such as carbon can be used. Examples of the transparent conductive inorganic oxide fine particles include tin oxide, Sb, F or P-doped tin oxide, indium oxide, Sn or F-doped indium oxide, antimony oxide, and lower-order titanium oxide. ..

【0023】

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

【0024】

In particular, when the transparent conductive fine particle layer contains the transparent conductive inorganic oxide fine particles in addition to the metal fine particles, the transparent conductive fine particles have excellent transparency as compared with the case where the transparent conductive fine particle layer is composed of only the metal fine particles. Layers can be formed on the substrate. Further, when the transparent conductive fine particle layer contains conductive fine particles other than the metal fine particles in this way, the transparent conductive fine particles are inexpensive as compared with the case where the transparent conductive fine particle layer is composed of only expensive metal fine particles. A coated base material can be produced.

【0025】

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

【0026】

The amount of conductive fine particles and matrix other than the metal fine particles contained in the transparent conductive fine particle layer is 10 depending on whether only the antistatic ability is imparted or the electromagnetic shielding ability is also imparted.¹⁰It is arbitrarily adjusted within the range where surface resistance of Ω / or less can be obtained, and each type, the metal type of the metal fine particles contained in the transparent conductive fine particle layer, the average particle size, and the thickness of the transparent conductive fine particle layer. It also differs depending on the material and thickness of the transparent film formed on the transparent conductive fine particle layer, and cannot be unconditionally specified. However, the electromagnetic shielding effect can be exhibited10²~10⁴When a substrate with a transparent conductive coating having a surface resistance of Ω / is obtained, the conductive fine particles other than the metal fine particles contained in the transparent conductive fine particle layer are 4 parts by weight or less per 1 part by weight of the metal fine particles. The matrix content is preferably 0.2 parts by weight or less per 1 part by weight of all the conductive fine particles.

【0027】

Considering that the refractive index of the transparent conductive fine particle layer is usually 1.6 to 2.5, the thickness of the transparent conductive fine particle layer is because the base material with the transparent conductive coating exhibits an excellent antireflection effect. It is desirable that the temperature is in the range of 50 to 200 nm.

【0028】

A base material with a transparent conductive coating having a transparent conductive fine particle layer as described above is 10¹⁰It has a wide range of surface resistance of Ω / or less, of which 10²~10⁴A base material with a transparent conductive coating having a surface resistance of Ω / has an excellent electromagnetic shielding effect. Therefore, this 10²~10⁴When the front plate of the cathode ray tube is constructed of a base material with a transparent conductive coating having a surface resistance of Ω / , this causes electromagnetic waves conventionally emitted from the front plate and the like, and is accompanied by the emission of such electromagnetic waves. The electromagnetic field generated by the above can be shielded.

【0029】

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 fine particle layer is further formed on the transparent conductive fine particle layer. This transparent film can be formed of, for example, silica having a refractive index of 1.45 after the film is formed, similar to the above matrix. In addition, the transparent film is composed of fine particles made of a low refractive index material such as magnesium fluoride, and if necessary, a small amount of conductive fine particles and / or addition so as not to impair the transparency and antireflection performance of the transparent film. It may contain agents such as dyes or pigments.

【0030】

The transparent coating as described above has a refractive index smaller than that of the transparent conductive fine particle layer, and has a sufficient size for providing a base material with a transparent conductive coating having excellent antireflection performance. It has a difference in refractive index.

【0031】

The film thickness of the transparent coating is preferably in the range of 100 to 300 nm in order for the transparent conductive coating base material to exhibit an excellent antireflection effect. The base material with a transparent conductive coating according to the present invention includes the above-mentioned transparent conductive fine particle layer and transparent coating, and a transparent conductive fine particle layer is formed on the base material, and the transparent conductive fine particle layer is formed on the transparent conductive fine particle layer. A transparent film is formed, which is necessary for electromagnetic shielding.²~10⁴It has a surface resistance of Ω / and can be adjusted to have sufficient antireflection performance in the visible light region and the near infrared region. When a base material with a transparent conductive coating whose surface resistance and antireflection performance are adjusted in this way is used for the front plate of a display device such as a cathode ray tube that emits electromagnetic waves, it occurs with the emission of electromagnetic waves and electromagnetic waves. In addition to being able to shield the electromagnetic field, the reflected light from the front plate can be prevented.

【0032】

Method for manufacturing a base material with a transparent conductive coating Next, the method for producing the transparent conductive film-coated base material according to the present invention as described above will be described.

【0033】

In the above-mentioned substrate with a transparent conductive coating, a transparent conductive fine particle layer composed of metal fine particles having an average particle size of 2 to 200 nm is formed on the substrate, and then the refractive index is higher than that of the fine particle layer on the fine particle layer. Manufactured by forming a low transparent film.

【0034】

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

【0035】

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

【0036】

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

【0037】

In the present specification, the matrix-forming component means a component that functions as a binder for granular components such as conductive fine particles, and for example, when the matrix is silica, it means a hydrolyzable polycondensable organic silicon compound or a silica sol. To do.

【0038】

Further, as the hydrolyzable polycondensable organic silicon compound, an alkoxysilane represented by the following formula [I]: R_aSi (OR')_4-a ... [I] (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 a carbon atom number. Alkyl groups 1-8, -C₂H₄OC_nH_{2n + 1}(N = 1 ~ 4) or a hydrogen atom, where a is an integer of 0 ~ 3).

【0039】

Specific examples of such alkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraoctylsilane, methyltrimethylsilane, methyltriethoxysilane, ethyltriethoxysilane, and methyltriiso. Examples thereof include propoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, and dimethyldimethoxysilane.

【0040】

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

【0041】

Hydrolysis of alkoxysilane as described above Acid / SiO₂= 0.0001 ~ 0.05 (weight / weight) and Water / SiO₂= 4 ~ 16 (mol mol) (In the above formula, SiO₂The alkoxysilane is SiO₂It is a value converted to. ) Is preferable.

【0042】

When preparing the coating liquid for forming a transparent conductive fine particle layer used in the present invention, water and / or an organic solvent is used as a dispersion medium for the metal fine particles, and the metal fine particles as described above are further contained in the dispersion medium. If necessary, conductive fine particles other than metal fine particles, other additives, and matrix-forming components are added.

【0043】

Among these, examples of the organic solvent include alcohols such as methanol, ethanol, propanol, butanol, diacetone alcohol, furfuryl alcohol, ethylene glycol and hexylene glycol, esters such as acetate methyl ester and acetate ethyl ester, and diethyl ether. , Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and other ethers, acetone, methyl ethyl ketone, acetyl acetone, acetoacetic acid ester and other ketones. One or more of them are used.

【0044】

The solid content concentration in the coating liquid for forming the transparent conductive fine particle layer used in the present invention, that is, the concentration of the component forming the transparent conductive fine particle layer is such as the fluidity of the coating liquid, the metal fine particles in the coating liquid, and the like. From the viewpoint of dispersibility of granular components and the like, it is preferably 15% by weight or less. When a matrix-forming component is contained in the coating liquid for forming a transparent conductive fine particle layer, the concentration of the matrix-forming component is a part of the solid content concentration. For example, the matrix-forming component is tetraethoxysilane. If, the concentration of matrix-forming components is SiO₂It is a value converted into a concentration.

【0045】

Further, in the coating liquid for forming a transparent conductive fine particle layer used in the present invention, cations such as alkali metal ions, ammonia ions and polyvalent metal ions present in the coating liquid, inorganic anions such as mineral acid, and acetic acid , The total ion concentration of organic anions such as formic acid is preferably 10 mmol or less per 100 g of total solids contained in the coating liquid. In such a coating liquid for forming a transparent conductive fine particle layer, the granular components contained in the coating liquid, particularly the conductive fine particles, are in a good dispersed state, and a coating liquid containing almost no agglomerated particles can be obtained. .. The monodisperse state of the granular components in the coating liquid is maintained even in the process of forming the transparent conductive fine particle layer, and as a result, the transparent conductive fine particle layer in which the granular components are monodispersed can be formed on the substrate. That is, no aggregated particles are observed in the transparent conductive fine particle layer formed from the coating liquid having a low ion concentration as described above. In the transparent conductive fine particle layer formed from the coating liquid having a low ion concentration as described above, the conductive fine particles such as metal fine particles can be satisfactorily dispersed. Therefore, the conductive fine particles in the transparent conductive fine particle layer It is possible to provide a transparent conductive fine particle layer having the same conductivity with less conductive fine particles as compared with the case where the particles are aggregated. In addition, a transparent conductive fine particle layer having no point defects and uneven thickness, which is considered to be caused by agglomeration of granular components, can be formed on the substrate.

【0046】

The deionization method for obtaining a coating liquid having a low ion concentration as described above is particularly limited as long as the ion concentration finally contained in the coating liquid is within the above range. However, as a preferable deionization method, either a dispersion liquid of granular components used as a raw material of a coating liquid and / or a liquid containing a matrix-forming component, or a coating liquid prepared from each liquid is cation. Examples thereof include a method of contacting with an exchange resin and / or an anion exchange resin, and a method of cleaning the liquid using an ultrafiltration membrane for any of these liquids.

【0047】

When forming the transparent conductive fine particle layer on the base material, any method capable of forming the transparent conductive fine particle layer by applying and drying the above-mentioned coating liquid for forming the transparent conductive fine particle layer on the base material. Can be adopted. For example, as such a method, a coating liquid for forming a transparent conductive fine particle layer is applied onto a substrate by a dipping method, a spinner method, a spray method, a roll coater method, a flexographic printing method, or the like, and then the obtained coating is applied. Examples include a method of drying the film. This coating film is usually dried at room temperature to 90 ° C, and if the coating liquid contains a matrix-forming component, the dried coating film may be heat-treated to 150 ° C or higher. preferable.

【0048】

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

【0049】

As the electromagnetic wave irradiated to promote the curing of such a matrix-forming component, ultraviolet rays, electron beams, X-rays, γ-rays and the like are used depending on the type of the matrix-forming component. For example, in order to accelerate the curing of the ultraviolet curable matrix-forming component, for example, the emission intensity is maximized at about 250 nm and 360 nm, and the light intensity is 10 mW / m.²Using the above high-pressure mercury lamp as an ultraviolet source, 100 mJ / cm²Ultraviolet rays with the above energy amount are irradiated.

【0050】

Further, among the matrix-forming components, there is a matrix-forming component whose curing is promoted by an active gas such as ammonia or ozone. A matrix is formed by treating a transparent conductive fine particle layer containing such a matrix-forming component in a curing-accelerating gas atmosphere having a gas concentration of 100 to 100,000 ppm, preferably 1000 to 10,000 ppm for 1 to 60 minutes. Curing of the components can be significantly accelerated.

【0051】

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

【0052】

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 vapor deposition method, a sputtering method, or an ion plating method, or a dipping method or spinner as described above. A wet thin film forming method such as a method, a spray method, a roll coater method, or a flexographic printing method can be adopted.

【0053】

When the transparent film is formed by the wet thin film forming method, a transparent film forming coating solution in which the matrix forming component as described above is dissolved or dispersed in water or an organic solvent can be used as the transparent film forming component. ..

【0054】

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

【0055】

In this case, if the above-mentioned deionization treatment is applied to the coating liquid for forming a transparent film to reduce the ion concentration contained in the coating liquid within the above-mentioned range, the dispersibility of the granular components in the transparent film is improved. It becomes good, and it becomes possible to provide a transparent film having an even thickness.

【0056】

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

【0057】

Further, the transparent conductive fine particle layer formed on the substrate is preheated to about 40 to 90 ° C, and the coating liquid for forming the transparent film is applied onto the transparent conductive fine particle layer by a spray method while maintaining this temperature. Then, when the heat treatment as described above is performed, ring-shaped irregularities are formed on the surface of the coating film, and an anti-glare transparent conductive coating base material with less glare can be obtained.

【0058】

Display device Of the transparent conductive coated base materials manufactured as described above, 10 required for electromagnetic shielding.²~10⁴A base material with a transparent conductive coating having a surface resistance of Ω / and sufficient antireflection performance in the visible light region and the near infrared region is used as a front plate of a display device.

【0059】

The display device according to the present invention is a device for electrically displaying an image such as a cathode ray tube (CRT), a vacuum fluorescent display (FIP), a plasma display (PDP), a liquid crystal display (LCD), and the like as described above. It has a front plate made of a transparent conductive filmed base material.

【0060】

When a display device provided with a conventional front plate is operated, an image is displayed on the front plate and at the same time an electromagnetic wave is emitted from the front plate, and this electromagnetic wave affects the human body of the observer. In the device, the front plate is 10²~10⁴Since it is composed of a base material with a transparent conductive coating having a surface resistance of Ω / , it is possible to effectively shield such an electromagnetic wave and an electromagnetic field generated by the emission of the electromagnetic wave.

【0061】

Further, when reflected light is generated on the front plate of the display device, the reflected light makes it difficult to see the displayed image. However, in the display device according to the present invention, the front plate has sufficient antireflection in the visible light region and the near infrared region. Since it is composed of a base material with a transparent conductive coating having high performance, such reflected light can be effectively prevented.

【0062】

Further, the front plate of the brown tube is composed of the base material with the transparent conductive coating according to the present invention, and a small amount of the transparent conductive coating is applied to at least one of the transparent conductive fine particle layer and the transparent coating formed on the transparent conductive fine particle layer. When the dyes or pigments of the above are contained, these dyes or pigments absorb light having a wavelength unique to each of the dyes or pigments, which can improve the contrast of the displayed image transmitted from the brown tube.

【0063】

[Effect of the invention]

In the substrate with a transparent conductive coating according to the present invention, a transparent conductive fine particle layer is formed on the transparent substrate, and a transparent coating having a lower refractive index than the transparent conductive fine particle layer is further formed on the transparent conductive fine particle layer. It is formed.

【0064】

According to the present invention, the transparent conductive fine particle layer contains metal fine particles as a conductive substance, and therefore, even if the film thickness is reduced, the surface resistance is higher than that of the conventional coating containing only the conductive oxide. Therefore, by forming a transparent film having a low refractive index on the conductive fine particle layer, a transparent conductive film having an excellent electromagnetic shielding effect and an excellent antireflection effect is attached. A substrate can be provided.

【0065】

Further, when the ion concentration of cations, anions, etc. contained in the coating liquid for forming the transparent conductive fine particle layer used in the present invention is adjusted to a very small amount, the dispersed state of the conductive fine particles in the coating liquid is changed. It becomes extremely good, and this good dispersed state of the conductive fine particles is maintained even in the process of forming the conductive fine particle layer, and aggregation of the fine particles does not occur.

【0066】

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

【0067】

Thus, according to the present invention, 10²~10⁴It is possible to provide a base material with a transparent conductive coating having a surface resistance of Ω / and excellent antireflection performance. Further, in the display device according to the present invention, since the base material with a transparent conductive coating having excellent surface resistance and antireflection performance as described above is used for the front plate, the antireflection effect is excellent, and at the same time, electromagnetic waves and electromagnetic waves are generated. Excellent electromagnetic field shielding effect.

【0068】

[Example]

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

【0069】

[Manufacturing Example]

a) Conductive fine particle dispersion Table 1 below shows the colloidal solution of the metal fine particles and the dispersion liquid of the conductive fine particles other than the metal fine particles used in this example.

【0070】

Of these, the colloidal solutions of Au, Ag, and Pd were colloidal solutions manufactured by Vacuum Metallurgical Co., Ltd., and the colloidal solution of Rh was prepared by the following method. Add rhodium trichloride to a mixed solvent of methanol and water (40 parts by weight of methanol / 60 parts by weight of water) so that it becomes 2% by weight in terms of metal Rh, and add 0.01 part by weight of polyvinyl alcohol per 1 part by weight of metal Rh to reflux. A colloidal solution of Rh was obtained by heating in a flask with a vessel at a temperature of 90 ° C. for 5 hours.

【0071】

Sb-doped tin oxide (Sb-SnO)₂) Fine particles, Sn-doped indium oxide (Sn-In)₂O₃) The mixed fine particle dispersion shown in Table 1 below was prepared using fine particles and conductive carbon (manufactured by Tokai Carbon Co., Ltd.).

【0072】

Of these, Sb-doped tin oxide fine particles and Sn-doped indium oxide fine particles were prepared as follows. Sb-doped tin oxide fine particles An aqueous solution was prepared by dissolving 333 g of potassium nitrate and 69.5 g of spout stone in 1019 g of pure water. This aqueous solution was added over 12 hours to 1876 g of pure water maintained at 50 ° C. During this time, the pH in the system was maintained at 10. From the obtained Sb-doped tin oxide hydrate dispersion, Sb-doped tin oxide hydrate is filtered through an ultrafiltration membrane, washed, dried, and then fired in air at a temperature of 550 ° C for 3 hours. Obtained Sb-doped tin oxide fine particles. Sn-doped indium oxide A solution obtained by dissolving 79.9 g of indium nitrate in 686 g of water and a solution obtained by dissolving 12.7 g of potassium nitrate in a 10 wt% potassium hydroxide solution were prepared.

【0073】

These solutions were added over 2 hours to 1000 g of pure water maintained at 50 ° C. During this time, the pH in the system was maintained at 11. Sn-doped indium oxide hydrate was filtered off from the obtained Sn-doped indium oxide hydrate dispersion, washed, dried, and then calcined in air at a temperature of 350 ° C. for 3 hours, and further 600 in air. Sn-doped indium oxide fine particles were obtained by firing at a temperature of ° C for 2 hours.

【0074】

[table 1]

<img file="JPH0877832A_D0001.tif" />【0075】

b) Preparation of liquid containing matrix-forming components Ethyl orthosilicate (SiO)₂: 28% by weight) 50 g, ethanol 194.6 g, concentrated nitric acid 1.4 g and pure water 34 g mixed solution is stirred at room temperature for 5 hours and SiO₂A liquid containing a matrix-forming component having a concentration of 5% by weight was prepared. c) Preparation of coating liquid for forming transparent film (upper layer) A mixed solvent of ethanol / butanol / diacetone alcohol / isopropanol (2: 1: 1: 5 weight mixing ratio) is added to the solution containing the above matrix-forming component, and SiO is added.₂A coating liquid for forming a transparent film having a concentration of 1% by weight was prepared. d) Preparation of coating liquid for forming transparent conductive fine particle layer The transparent conductive fine particle layer forming coating liquids C-1 to C-8 shown in Table 2 were prepared from the colloidal solution of the metal fine particles shown in Table 1, the dispersion liquid of the conductive fine particle mixture, and the liquid containing the matrix-forming component. ..

【0076】

The ion concentration in each coating solution was adjusted by deionizing each coating solution shown in Table 2 with an amphoteric ion exchange resin (Diaion SMNUPB manufactured by Mitsubishi Kasei Co., Ltd.).

【0077】

The ion concentration in the coating liquid was measured as follows. The alkali metal ion concentration and the alkaline earth metal ion concentration were measured by the atomic absorption method, the other metal ion concentrations were measured by emission spectroscopy, and the ammonium ion and anion ion concentrations were measured by the potential differential titration method.

【0078】

[Table 2]

<img file="JPH0877832A_D0002.tif" />【0079】

[Examples 1 to 7, Comparative Example 1]

While maintaining the surface of the panel glass for cathode ray tubes (14 ) at a temperature of 40 ° C, apply the above coating liquids C-1 to C-8 for forming a transparent conductive fine particle layer under the conditions of 100 rpm and 90 seconds by the spinner method, respectively. It was applied.

【0080】

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

【0081】

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

【0082】

The results are shown in Table 3.

【0083】

[Table 3]

<img file="JPH0877832A_D0003.tif" />