JP2659541B2 - Transparent electrode for transparent tablet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transparent electrode for a transparent tablet, and more particularly, to a transparent electrode having corrosion resistance and antioxidation, excellent mechanical strength, and direct contact with the outside. The present invention relates to a transparent tablet transparent electrode that can be used for applications.

[Conventional technology]

Transparent electrodes formed on glass or plastic (hereinafter referred to as glass etc.) substrates are transparent electrodes for liquid crystal displays, electrochromic displays, plasma displays, electroluminescence, display sections of fluorescent display tubes or membranes because of their excellent transparency. It is used as a transparent electrode for switches and the like.

The transparent electrode used in such a liquid crystal display or the like is formed on a substrate, but the transparent electrode is used directly inside the device without directly contacting the outside. The reason why the transparent electrode must be used inside the device, not in a place where it is in contact with the outside world, is as follows. That is, generally, these transparent electrodes are formed on a substrate such as glass by a vapor phase method such as a vapor deposition method or a sputtering method, but these transparent electrodes are corroded by an acid or alkali, or oxidized in the air. In addition, the electrical resistance varies depending on the temperature, humidity, and the like, and furthermore, the mechanical strength is weak, so that the transparent electrode is easily damaged and the wire is disconnected.

In recent years, it has become necessary to apply a transparent electrode to a transparent digitizer or an input surface for a telewriting terminal, which has been developed for the purpose of directly inputting information to a computer or the like from outside the display device.

For example, FIGS. 4 and 5 show an example of a transparent digitizer in which a transparent electrode 12 is formed on the surface of a glass plate 11,
Electrodes are drawn out from the four sides by diodes 13, 14, 15, and 16. Switches 18 and 19 for this transparent digitizer
Are connected, and the electric pen 17 is brought into contact with the surface thereof, whereby a current flows through the transparent electrode 12. Since the current value changes depending on the contact position of the electric pen 17, the contact position can be calculated by measuring the current value.

[Problems to be solved by the invention]

However, transparent electrodes 12 used for such purposes
Will come into direct contact with the outside world. However, because the mechanical strength of the conventionally known transparent electrode 12 is weak,
When it comes into contact with an input terminal such as an input pen,
And the transparent electrode 12 is easily corroded by acid, alkali, or air, and the like, and the transparent electrode 12 cannot be applied to the transparent digitizer, the telewriting terminal, or the like.

The present invention solves the problems associated with the prior art described above, and provides a transparent electrode for a transparent tablet which has excellent corrosion resistance, antioxidant properties, and mechanical strength, and which can be used for direct contact with the outside world. The purpose is to provide.

[Means for solving the problem]

The present invention provides a transparent electrode film, an anisotropic conductive film in which metal particles are monodispersed in an organic binder or an inorganic binder, and a transparent conductive protection in which conductive oxide powder is further dispersed in a binder resin. And a film are sequentially formed.

[Action]

In the present invention, input is performed by conducting to the lower transparent electrode film through the monodispersed metal particles. Then, the transparent electrode film is protected by the anisotropic conductive film thereon so as not to directly contact the outside.

The transparent conductive protective film protects the metal particles from direct contact with the outside.

〔Example〕

An embodiment of the transparent electrode for a transparent tablet according to the present invention will be described below.

FIG. 1 is a view for explaining the principle of a transparent electrode for a transparent tablet according to the present invention, wherein 1 is a transparent insulating substrate such as plastic or glass, 2 is a transparent electrode film formed on the transparent insulating substrate 1, and 3 is The metal particles 4 are dispersed in the anisotropic conductive film and are formed on the transparent electrode film 2. Hereinafter, each will be described.

The transparent insulating substrate 1 used in the present invention can be made of plastic or glass.

Next, the transparent electrode film 2 formed on the transparent insulating substrate 1 is preferably transparent. It is desirable that the surface resistance of the transparent electrode film 2 is 10 to 5000 Ω / □ and the total light transmittance is 65% or more, more preferably, the surface resistance is 10 to 1000 Ω / □ and the total light transmittance is 70% or more. Surface resistance 5000Ω
When the ratio exceeds / □, the surface resistance becomes too high, which is not preferable. When the total light transmittance is less than 65%, the transparency deteriorates, which is not preferable.

The anisotropic conductive film 3 according to the present invention is, as shown in FIG.
Metal particles 4 are monodispersed in an organic binder or an inorganic binder (hereinafter referred to as a binder for an anisotropic conductive film), and a part of the metal particles 4 is exposed on the surface. Formed. Thereby, the transparent electrode film 2
Since there is no direct contact with the outside, corrosion and oxidation by acid, alkali or air can be prevented. further,
Since an input terminal such as an input pen does not directly contact the transparent electrode film 2, disconnection does not occur and input failure is eliminated.

In the anisotropic conductive film 3, a current flows only from the exposed portion to the lower transparent electrode film 2 through the metal particles 4, and the metal particles 4 do not contact each other in the lateral direction inside the film. No current flows because it is monodispersed inside. The metal particles 4 may be anything as long as they have a small electric resistance, but specifically, Au, Ag,
Noble metal particles such as Pt and Pd, metal particles such as Sn, Cu, Ni, Zn, Fe and Pb, or alloys of the above noble metals and metals can be used. Further, those in which the noble metal or metal is plated with inorganic particles or resin particles can also be used. Metal particles 4
Can be used if its particle size is 2 to 30 μm.
If the thickness is less than 2 μm, the input terminal breaks through the anisotropic conductive film 3 or wears out, so that the transparent electrode film 2 is liable to be broken. If it exceeds 30 μm, the transparency is reduced.

As the organic binder or the inorganic binder used for the binder for the anisotropic conductive film, any binder having good adhesion to the transparent electrode film 2 can be used. It can be used if the performance is improved. Specifically, as an organic binder, acrylic resin such as methacrylic resin, urea resin, amino resin such as melamine resin, polyurethane resin, polyester resin such as alkyd resin, epoxy resin, silicone resin, vinyl chloride resin, A vinyl resin such as a vinylidene chloride resin, a vinyl acetate resin, a polyvinyl carbazole resin, a butyral resin, a fluorine resin, a polyphenylene oxide resin, an ultraviolet curable resin, or a cellulose derivative is used. Further, a mixture of the above resins or a copolymer of the above resins may be used alone or in combination of two or more.

As the inorganic binder, a colloid containing an organic solvent as a dispersion medium is preferable, and silica, alumina, zirconia, titania, tin, or the like can be used as the colloid. The particle size of the colloid may be 5 to 80 mμ. If the thickness exceeds 80 μm, the transparency of the anisotropic conductive film 3 deteriorates.

The mixing ratio of the metal particles 4 and the organic binder or the inorganic binder is such that the metal particles 4 are 0.1 to 10 v
ol%, preferably 1 to 6 vol%. If it is less than 0.1 vol%, the input between the metal particles 4 is too far apart to make the input unclear, and if it exceeds 10 vol%, the adhesion to the transparent electrode film 2 and the transparency of the anisotropic conductive film 3 are poor. Because it becomes. Further, the thickness of the anisotropic conductive film 3 is smaller than the particle size of the metal particles 4 so that the metal particles 4 are exposed on the surface. The anisotropic conductive film 3 can be obtained by a coating for an anisotropic conductive film in which metal particles 4 and a binder for an anisotropic conductive film are dissolved or dispersed in a solvent described later.

Thus, a transparent electrode can be obtained by sequentially laminating the transparent electrode film 2 and the anisotropic conductive film 3 on the transparent insulating substrate 1,
It can be applied to a transparent digitizer or a telewriting terminal.

However, this configuration has the following problems. One is that since the metal particles 4 are exposed, the oxidation or corrosion of the metal is apt to occur, so that the electrical resistance fluctuates or the metal particles 4
Are worn by the input terminal. In addition, since there is a binder which is an insulator between the metal particles 4, no input is made when the input terminal contacts only the binder, and further, when the input terminal touches or separates from the metal particle 4. Electric spark occurs. The present invention has solved these problems, and FIG. 2 shows an embodiment thereof.

In FIG. 2, reference numeral 5 denotes a transparent conductive protective film formed on the anisotropic conductive film 3, and the other components are the same as those in FIG. The transparent conductive protective film 5 has a thickness of 2 to 30 μm, and preferably 3 to 30 μm in order to further increase the corrosion resistance and film strength of the transparent conductive protective film 5. If the thickness of the transparent conductive protective film 5 is less than 2 μm, the transparent conductive protective film 5
On the other hand, if the thickness exceeds 30 μm, the transparency of the transparent conductive protective film 5 is deteriorated, and the transparency of the transparent electrode for a transparent tablet is undesirably reduced. Further, the volume resistance value of the transparent conductive protective film 5 itself is preferably 10 ⁻¹ to 10 ⁶ Ω · cm. Also,
If the volume resistivity of the transparent conductive protective film 5 itself exceeds 10 ⁶ Ω · cm, it becomes difficult for current to flow in the thickness direction, and the transparent electrode film 2
Is not preferred because the function as an electrode is impaired.

Therefore, the transparent electrode for a transparent tablet shown in FIG. 2 in which the transparent electrode film 2, the anisotropic conductive film 3, and the transparent conductive protective film 5 are sequentially formed on the transparent insulating substrate 1, has a surface resistance of 2 ×. It is preferably at most 10 ³ Ω / □. If it exceeds the above value, it cannot be used as a transparent electrode for a transparent tablet.

The transparent conductive protective film 5 is made of a transparent conductive protective film paint in which a conductive oxide powder (hereinafter, referred to as c) is dispersed in a transparent conductive protective film binder resin (hereinafter, referred to as d). It is formed on the anisotropic conductive film 3.

The conductive oxide powder c in the paint for the transparent conductive protective film used at this time is a conductive indium oxide powder in which one or more elements such as Sn, F, and Cl are doped into indium oxide, or an oxide. Conductive tin oxide powder in which one or more elements such as Sb, F, Cl, and P are doped into tin is used.
Further, the conductive indium oxide powder and the conductive powder tin powder may be mixed and used. The average particle size of the conductive indium oxide powder or conductive tin oxide powder in the coating is 0.01 to 0.6 μm, preferably 0.0 to 0.6 μm.
It is preferably in the range of 1 to 0.5 μm and further contains only a small amount of coarse particles of 0.8 μm or more. The method for producing these powders is not particularly limited, but is preferably
Preferred is a conductive fine powder obtained according to JP-A-51008.

The method for preparing the conductive fine powder will be described. The conductive fine powder gradually hydrolyzes a compound in a liquid while maintaining an aqueous solution of a tin compound or an indium compound under a pH condition of 8 to 12. Thereby, a sol containing colloidal particles of a metal oxide, a hydrated oxide or a metal hydroxide is generated, and then the sol is dried, calcined, and pulverized. The starting material is water-soluble,
In addition, tin compounds or indium compounds that can be hydrolyzed in the pH range of 8 to 12 are used, and specifically, tin compounds such as potassium stannate and sodium stannate, and indium compounds such as indium nitrate and indium sulfate can be used. It is.

When the metal species contained in the aqueous solution of the tin compound or the indium compound (hereinafter referred to as a raw material liquid) is any one of tin and indium, the obtained conductive fine powder is composed of tin oxide or indium oxide. By dissolving a small amount of a different metal in the raw material liquid, a conductive fine powder doped with a different metal can be produced. By the way, by dissolving a small amount of tartar or ammonium fluoride in the raw material liquid containing the tin compound, it is possible to obtain a conductive fine powder in which antimony or fluorine is doped into tin oxide, and the indium compound is removed. By dissolving a small amount of a tin compound in a contained raw material liquid, a conductive fine powder in which indium oxide is doped with tin can be obtained.

The conductive fine powder doped with a dissimilar metal can also be produced by the following method. That is, a tin compound is used as a raw material liquid, a sol is generated by gradually hydrolyzing the tin compound in the liquid under the above-mentioned pH conditions, colloid particles are collected from the sol, and then an antimony compound and a phosphorus compound A method of impregnating the colloid particles with at least one aqueous solution of a fluorine compound and then drying and baking the particles to produce a conductive fine powder in which a tin compound is doped with antimony, phosphorus fluorine, or the like. Can be. In addition, an aqueous solution of an indium compound is used as a raw material liquid, a sol is generated in the same manner as described above, and after collecting colloid particles from the sol, a tin compound and / or
Alternatively, a conductive fine powder in which an indium compound is doped with tin and / or fluorine can be produced by impregnating the colloid particles with an aqueous solution of a fluorine compound, and then drying and firing the particles. Even when the raw material liquid is a tin compound, and when a by-product salt is generated in the process of generating a sol even when the raw material liquid is an indium compound,
Not only does the colloidal particles easily agglomerate, but the specific resistance of the finally obtained conductive fine powder increases due to contamination with by-product salts. Prior to impregnating the collected colloid particles with the aqueous metal compound solution, it is recommended to remove by-product salts from the colloid particles.

The concentration of the tin compound or the indium compound contained in the raw material liquid can be arbitrarily selected, but is generally 0.5 to 30 watts.
It is preferably in the range of t%.

When a compound of a different metal serving as a dopant of the tin compound or the indium compound contained in the above-described raw material liquid is present, together with the different metal compound, while hydrolysis occurs under the condition of pH 8 to 12, Always keep the pH of the reaction system at 8
Must be kept in the range of ~ 12. pH8 below pH8
When the particle size distribution becomes broad and the pH value further decreases even when the temperature is close to, the metal oxide generated by hydrolysis precipitates and cannot be dispersed in the liquid as colloid particles,
Therefore, the sol cannot be adjusted. In addition, when the pH of the reaction system exceeds 12, although it is not impossible to adjust the sol, when washing the colloid particles separated from the sol, the alkali cannot be sufficiently removed. This is because the conductivity of the obtained conductive fine powder deteriorates.

There is no particular limitation on the solid content concentration of the sol liquid generated in the reactor, but generally, as the concentration increases, the particle size distribution of the generated colloidal particles tends to become broader. The hydrolysis reaction temperature can always be arbitrarily selected within the range of 30 to 90 ° C.

The average particle size of the colloidal particles obtained by hydrolysis is in the range of 0.05 to 0.3 μm, preferably 0.07 to 0.2 μm, and the particle size distribution is such that 80% or more of all the particles are 0.5 to 1.5 times the average particle size. In range.

After the preparation of the sol solution, the sol solution is filtered to collect colloidal particles, and after removing by-product salts and others attached to the particles by washing, drying, and further calcination and then pulverization, the conductive fine powder is obtained. Can be obtained. The particles filtered out from the sol liquid are slightly sintered in the firing step, so the average particle size of the conductive fine powder is about 20 to 50 μm, and the specific surface area of the conductive fine powder is 50 m ² / g or less. It is.

On the other hand, the specific surface area of the conductive fine powder produced through a conventionally known precipitation forming step is 70 to 100 m ² / g.
This indicates that the conductive fine powder obtained as described above is composed of primary particles larger than the conventional conductive fine powder. The conductive fine powder thus obtained can be easily released from its sintered state by pulverization, and the average particle in the coating material is 0.6 μm or less in the coating material by ordinary pulverization means. Obtainable. The conductive fine powder thus obtained contains only a small amount of coarse particles of, for example, 0.8 μm or more. The pulverization of the conductive fine powder may be performed before mixing with other components such as a binder resin, or may be performed after mixing with other components such as a binder resin. The grinding of the conductive fine powder can be performed by a conventionally known grinding method,
For example, devices such as an attritor, a sand mill, a ball mill, and a three-roll machine can be used.

Further, the binder resin d for a transparent conductive protective film used in the paint for a transparent conductive protective film of the present invention is, specifically,
For example, acrylic resins such as methacrylic resins, amine resins such as urea resins and melamine resins, polyester resins such as polyurethane resins and alkyd resins, epoxy resins, silicone resins, vinyl chloride resins, vinylidene chloride resins, and vinyl acetate Resin, polyvinyl carbazole resin, vinyl resin such as butyral resin, fluorine resin,
A polyphenylene oxide resin, an ultraviolet curable resin, a cellulose derivative, or the like is used. One or two of a mixture of the above resins, a copolymer of the above resins, and the like.
More than one species can be used in combination.

The mixing ratio of the conductive oxide fine powder and the binder resin d for the transparent conductive protective film is such that the conductive oxide powder c is 40 to 95 wt%, preferably 60 to 90 wt%, based on the total weight of both. , Preferably 70 to 85% by weight. If the conductive oxide powder c is less than 40% by weight, the conductivity of the coating film obtained will be poor. On the other hand, if it exceeds 95% by weight, the adhesion between the transparent conductive protective film 5 and the anisotropic conductive film 3 and the obtained film will not be obtained. This is not preferable because the resulting transparent conductive protective film 5 has poor transparency.

The transparent electrode film 2 is made of a conductive indium oxide film (ITO film) or a conductive tin oxide film (NESA film) on the transparent insulating substrate 1 by a vapor phase method such as a vapor deposition method, a sputtering method, and a CVD method.
And the like. Also, a transparent electrode coating material in which conductive indium oxide powder (hereinafter referred to as a) is dispersed in a binder resin (hereinafter referred to as a transparent electrode film binder resin b) having a carrier moving speed of 10 ⁻⁸ cm ² / V · sec or more. Can be formed on the transparent insulating substrate 1.

The conductive indium oxide powder a used at this time is:
Among the conductive oxide powders c used in the transparent conductive protective film coating, conductive indium oxide powder can be used.

Examples of the transparent electrode film binder resin b used in the transparent electrode film paint include conductive resins such as polypyrrole, polyacetal, and polypyridine, or polycarbazole,
A photoconductive resin such as diphenylaminostyrene can be used. If the carrier moving speed is less than 10 ⁻⁸ cm ² / V · sec, the resistance becomes too high and the function as the transparent electrode film 2 cannot be maintained. Further, when one or more of ultraviolet curable binder resin, thermoplastic binder resin, and thermosetting binder resin are mixed with the transparent electrode film binder resin b, the coatability of the transparent electrode film paint is improved, The adhesion between the resulting transparent electrode film 2 and the transparent insulating substrate 1 can be improved. Specific examples of the ultraviolet curable binder resin, thermoplastic binder resin, and thermosetting binder resin include acrylic resins such as methacrylic resin, polyacetylene resins, urea resins, amino resins such as melamine resins, and polyamide resins. Resin, polyimide resin, polyamide imide resin, polyurethane resin, polyether resin, polyester resin such as alkyd resin,
Epoxy resin, chlorinated resin such as chlorinated polyether resin, polyolefin resin such as polyethylene resin and polypropylene resin, polycarbonate resin, silicone resin, polystyrene resin, ABS resin, polyamine sulfone resin, polyether sulfone Resin, polysulfone resin such as polyphenylene sulfone resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, polyvinyl carbazole resin, vinyl resin such as butyral resin, fluorine resin, polyphenylene oxide resin, polypyrrole resin, poly A pharafenenlen-based resin, an ultraviolet curable resin, a cellulose derivative, or the like is used. Further, a mixture of the above resins, a copolymer of the above resins, or the like, may be used alone or in combination of two or more.

The mixing ratio of the binder resin b for the transparent electrode film and the ultraviolet curable binder resin, the thermoplastic binder resin, and the thermosetting binder resin is such that the carrier moving speed in the mixed binder resin is 10 ⁻⁸ cm ² / V · What is necessary is just to hold for sec or more. 10 ^-8
If it exceeds cm ² / V · sec, the resistance becomes too high and the function as the transparent electrode film 2 cannot be maintained. The carrier moving speed of the binder resin means a speed at which electrons or holes move in the resin when an electric field is applied to the binder resin. The carrier moving speed of such a binder resin is measured as follows.

A binder resin having a thickness of l is provided between electrodes at a distance of l. Next, the sample is irradiated with light to excite electrons in the sample and move the electrons to the positive electrode side. At this time, it detected at time t ₀ and the positive electrode was irradiated with light the difference between the time t ₁ that electrons reached by measuring. Here, the carrier moving speed function v (E) is represented by the following equation.

(In the formula, μ is the carrier moving speed, E is the electric field, and V is the voltage.) The ratio of the conductive indium oxide powder a to the binder resin b for the transparent electrode film is determined by the ratio of the conductive oxide to the total weight of both. The indium powder a is preferably 70 to 95% by weight. When the amount of the conductive indium oxide powder a is less than 70 wt%, the conductivity of the obtained coating film is deteriorated. On the other hand, when it exceeds 95 wt%, the adhesion between the transparent electrode film 2 and the transparent insulating substrate 1 and the obtained transparent electrode film are reduced. No. 2 is not preferred because the transparency is deteriorated.

In the paint for a transparent electrode film, the paint for an anisotropic conductive film and the paint for a transparent conductive protective film used in the present invention, the above-mentioned components are dissolved or dispersed in a solvent. Any material can be used as long as it can dissolve or dilute the binder resin b for the electrode film, the binder for the anisotropic conductive film, and the binder resin d for the transparent conductive protective film. Specifically, alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, diacetone alcohol and cyclohexanol, acetone, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, holon and isophorone Ketones, ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, carbitol, methyl carbitol, butyl carbitol, dioxane, esters such as ethyl acetate and n-butyl acetate, and petroleum naphtha such as hexane and cyclohexane Benzenes such as toluene, xylene, mesitylene, and solvent naphtha, N-methyl-2-pyrrolidone and its derivatives, etc. are used alone or in combination. Such a solvent is used in such an amount as to have a desired film thickness and a viscosity capable of applying a paint. When a water-soluble binder resin is used, water can be used as a solvent.

When producing a paint for a transparent electrode film, a paint for an anisotropic conductive film, and a paint for a transparent conductive protective film, the dispersibility of the conductive indium oxide powder a, the metal particles 4, and the conductive oxide powder c is improved. In order to prevent the particles from reaggregating, a surfactant or a coupling agent may be added to the coating for the transparent electrode film, the coating for the anisotropic conductive film, and the coating for the transparent conductive protective film. As the surfactant, anionic, nonionic, cationic and the like can be widely used. As the coupling agent, a silane-based, titanium-based, aluminum-based, zirconium-based, or magnesium-based coupling agent can be used.

Using the thus obtained transparent electrode film paint, anisotropic conductive film paint and transparent conductive protective film paint, conventionally known coating methods, such as a spinner method, a bar code method, a dip method, a Meyer bar method, The transparent electrode film 2, the anisotropic conductive film 3, and the transparent conductive protective film 5 are obtained by coating by an air knife method or a printing method such as a gravure screen roll coater and then drying.

In addition, since the transparent electrode film 2, the anisotropic conductive film 3, and the transparent conductive protective film 5 can be formed by a coating method, continuous production and low-cost production are possible.

FIG. 3 shows an example in which the present invention is applied to the transparent digitizer shown in FIG. 4, in which a transparent electrode film 21 is formed on a surface of a glass plate 20 by a vapor phase method, and a metal particle 22 is further coated thereon with a binder.
An anisotropic conductive film 24 dispersed in 23 is formed. Others are the same as FIG. The principle of coordinate detection is the same as that shown in FIG. 4. When the electric pen 17 is brought into contact with the surface of the transparent digitizer, the current does not flow in the anisotropic conductive film 24 in the lateral direction where the resistance is large. It flows in the vertical direction toward the electrode film 21. Since the detection of the coordinates is performed by the currents ( _Xa and _Xb ) flowing through the transparent electrode film 21, it is not affected by the resistance of the anisotropic conductive film 24. Therefore, even if the resistance value of the anisotropic conductive film 24 changes due to dirt or scratches on the surface of the anisotropic conductive film 24, if the electric pen 17 and the transparent electrode film 21 are conducted, the coordinates can be detected, and the coordinates can be detected. Detection accuracy does not deteriorate.

Hereinafter, specific examples and comparative examples of the present invention will be described, and their evaluation values are shown in Table 1. However, specific examples 1, 3, 5
Does not have a transparent conductive protective film.

[Specific Example 1] Silica sol (manufactured by Catalyst Chemical Industry Co., Ltd.) in which 2.4 g of silver-plated powder having an average particle diameter of 8 μm (manufactured by Catalyst Chemical Industry Co., Ltd., product name: P-500S, specific gravity 2.5) was dispersed in butanol , Trade name OSCAL-1532, concentration 30 wt%, average particle size 12 mμ, specific gravity 1.
4) The mixture was mixed in 100 g and sufficiently dispersed to obtain a paint for an anisotropic conductive film. This paint was applied on the transparent electrode film obtained in Comparative Example 1 described below using a spinner at 300 rpm, and then applied.
The composition was cured at 300 ° C. for 30 minutes to form an anisotropic conductive film (thickness: 3 μm).

[Specific Example 2] 150 g of antimony-doped conductive tin oxide powder (catalyst Kasei Kogyo Co., Ltd., trade name ELCOM TL-30) and 50 g of silicone resin (made by Toray Silicone, trade name SR-2410) were placed in 500 g of mesitylene. The mixture was further mixed and pulverized with a sand mill for 2 hours to obtain a paint for a transparent conductive protective film. This paint was applied on the anisotropic conductive film obtained in Example 1 using a spinner for 200 hours.
After application at rpm, dry at 120 ° C for 10 minutes,
Cured for a time to form a transparent conductive protective film (5 μm thick)
m).

[Specific Example 3] 6 g of Ni-plated powder having an average particle size of 15 μm (produced by Catalyst Chemical Industry Co., Ltd., product name: P-600S, specific gravity: 2.2) was epoxy resin (manufactured by Daicel Chemical Industries, Ltd., trade name: EHPE-3150). , Specific gravity 1.
2) 60 g and 40 g of phthalic anhydride in 30 g of ethyl acetate
The mixture was sufficiently mixed and dispersed sufficiently to obtain a paint for an anisotropic conductive film.
The coating was applied at 100 rpm on a transparent electrode film obtained in Comparative Example 2 using a spinner, and then applied at 120 ° C.
Cured for a time to form an anisotropic conductive film (9 μm thick)
m).

[Example 4] 150 g of fluorine-doped conductive indium oxide powder (trade name ELCOM TL130, manufactured by Catalyst Chemical Industry Co., Ltd.) and 50 g of an ultraviolet curable resin (trade name, DH-700 manufactured by Daihachi Chemical Co., Ltd.) were mixed with n-acetic acid. The mixture was added to 500 g of butyl, mixed, and pulverized with a sand mill for 2 hours to obtain a transparent conductive protective film paint. This paint was applied on the anisotropic conductive film obtained in Example 3 at 100 rpm using a spinner, and then cured with ultraviolet light to form a transparent conductive protective film (film thickness: 5 μm).

[Specific Example 5] 6 g of a gold-plated powder having an average particle size of 5 μm (product name: P-700S, specific gravity: 3.0, manufactured by Catalyst Chemical Industry Co., Ltd.)
100 g of a melamine resin (manufactured by Dainippon Ink and Chemicals, Inc., trade name: Acrydec, specific gravity 1.2) and 500 g of butyl carbitol acetate were mixed and sufficiently dispersed to obtain a coating for an anisotropic conductive film. This paint was screen-printed on the transparent electrode film obtained in Comparative Example 1 described later, and then cured at 180 ° C. for 1 hour to form an anisotropic conductive film (film thickness 4 μm).

[Specific Example 6] 150 g of conductive indium oxide powder doped with fluorine (trade name: ELCOM TL-130, manufactured by Catalyst Chemical Industry Co., Ltd.) and polyvinyl butyral resin (trade name: # 2000-L, manufactured by Decane) 35
g and 15 g of melamine resin (trade name: Super Beckamine J-820, manufactured by Dainippon Chemical Co., Ltd.) in 100 g of butyl carbitol acetate, mixed and pulverized with a sand mill for 2 hours to form a transparent conductive protective film. Paint was obtained. This paint was screen-printed on the anisotropic conductive film obtained in Example 5, and then cured at 150 ° C. for 1 hour to form a transparent conductive protective film (film thickness: 10 μm).

[Comparative Example 1] Indium oxide powder containing 5 wt% tin oxide powder was molded into a tablet shape, and then a temperature of 400 ° C and an oxygen partial pressure of 3 × 10 ^-4 Torr were applied on a glass plate using a 2 Kw electron gun. Deposition rate 3
A transparent electrode film was deposited at a rate of （/ sec (film thickness 1500Å).

[Comparative Example 2] 150 g of fluorine-doped conductive indium oxide powder (trade name: ELCOM TL-130, manufactured by Catalyst Kasei Kogyo Co., Ltd.) and polyvinyl carbazole (trade name, Zubicol, manufactured by Anan Perfume Co., Ltd., carrier moving speed: 10 ^{− (6} cm ² / V · sec) 37.5 g was added to 200 g of cyclohexanone, mixed, and pulverized with a sand mill for 2 hours to obtain a paint for a transparent electrode. The paint was applied to a transparent acrylic plate at 200 rpm using a spinner, and then cured with ultraviolet light to form a transparent electrode film (film thickness: 5 μm).

[Evaluation Method] Transparency: Total light transmittance (Tt) and haze (H) were measured by a haze computer (manufactured by Suga Test Instruments).

Conductivity: Surface resistance (R _S ) was measured with an electrode cell (YHP).

 Film strength: The following evaluation was performed.

1) It was evaluated by the pencil hardness test of JISDO202-71.

2) 400 g of sand was dropped for 2 minutes in accordance with the JIS H8682-80 sand erosion test, and the haze and surface resistance of the abraded surface were measured.

3) Slide the H pencil with a weight of 200 g with a width of 5 cm.
The number of reciprocations up to input failure such as line breakage was evaluated.

Acid resistance: immersed in a 50 wt% acetic acid aqueous solution at room temperature for 1 hour, pulled up, sufficiently washed with pure water, dried, and observed film peeling.

Alkali resistance 1% in aqueous solution of 15wt% ammonia at room temperature
After soaking for a period of time, the film was pulled up, washed sufficiently with pure water and dried, and the peeling of the film was observed.

Non-glare property: In the measurement of glossiness according to JIS K105-81, the glossiness (G) was evaluated at a measurement angle of 60 °.

In the sand removal test, ΔH and ΔR _S are represented by the following equations.

ΔH = H2−H1, where H1 is the base value before the test, H2 is the haze value after the test, and ΔR _S (surface resistance) is the same.

Further, after the acid resistance and alkali resistance tests, the film where the film was not peeled at all was evaluated as ○, and the film that was slightly peeled was evaluated as ×. Further, ΔH of Comparative Example 1 could not be measured because the film was peeled off.

〔The invention's effect〕

As described above in detail, the present invention provides a transparent electrode substrate, a transparent electrode film, an anisotropic conductive film in which metal particles are monodispersed in an organic binder or an inorganic binder, and a conductive oxide powder in a binder resin. And a transparent conductive protective film dispersed in order, have strong corrosion resistance to acids and alkali chemicals, and are not oxidized even when left in the air. Electric resistance is not affected. Further, since the mechanical strength is extremely excellent, it can be used as an input surface for a transparent digitizer or a tele-writing terminal which is directly written by an input terminal such as an input pen. In addition, since the outer surface is uneven, incident light from the outside is scattered and glare on the input surface can be prevented. Furthermore, although the transparent electrode for a transparent tablet of the present invention is transparent, it has a black color tone, so that it has an advantage that the contrast with the display screen is good and the image is easy to see.

Further, there is an advantage that oxidation and corrosion of the metal particles are prevented, and a reliable input is ensured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part for explaining the principle of the present invention, FIG. 2 is a cross-sectional view of a main part showing one embodiment of the present invention, and FIG. 3 shows a case where the present invention is applied to a transparent digitizer. FIG. 4 is a schematic diagram showing an example of a conventional transparent digitizer, and FIG. 5 is a schematic side view of the digitizer shown in FIG. In the figure, 1 is a transparent insulating substrate, 2 is a transparent electrode film, 3 is an anisotropic conductive film, 4 is metal particles, and 5 is a transparent conductive protective film.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsutsuo Koyanagi 1-14-12 Kasugadai, Yawatanishi-ku, Kitakyushu-shi, Fukuoka (72) Inventor Toshiro Komatsu 3-36-9 Nakakasai, Edogawa-ku, Tokyo NAC Amenity Kasai No. 901 (72) Inventor Ikutari Nozue 7-36, Otani-cho, Wakamatsu-ku, Kitakyushu-shi, Fukuoka (72) Inventor Gyoro 2530 Totonda, Oji-machi, Wakamatsu-ku, Kitakyushu-shi, Fukuoka (56) JP, A) JP-A-62-77626 (JP, A) JP-A-61-118825 (JP, A)

Claims (1)

(57) [Claims] A transparent electrode film, an anisotropic conductive film in which metal particles are monodispersed in an organic binder or an inorganic binder, and a transparent conductive film in which conductive oxide powder is dispersed in a binder resin. A transparent electrode for a transparent tablet, wherein a protective film and a protective film are sequentially formed.