JP2007095660A - Transparent conductive film or transparent conductive sheet, and touch panel using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent conductive film or a transparent conductive sheet which is superior in pen-sliding durability in the vicinity of frame when used for a touch panel and of which transparent conductive thin film is not destructed even after, in particular, a sliding test of 10,000 times at 2.5 N load using a pen made of polyacetal, and a touch panel using the same. <P>SOLUTION: This is a transparent conductive film in which a transparent conductive thin film having a metal oxide as a constituent component is laminated through a hardening material layer on a transparent plastic film (substrate). The transparent conductive thin film is amorphous and the carbon concentration contained in the transparent conductive thin film is 1×10<SP>20</SP>-1×10<SP>22</SP>(atoms/cm<SP>3</SP>). This is a transparent conductive sheet in which a transparent resin sheet is pasted up through an adhesive on the opposite face to the transparent conductive thin film face of the transparent conductive film. A touch panel in which at least one of panel plate is made of the transparent conductive film or the transparent conductive sheet is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transparent conductive film or a transparent conductive sheet in which a transparent conductive thin film is laminated on a base material made of a transparent plastic film via a cured product layer, and a touch panel using these, and in particular, a frame of a touch panel. The present invention relates to a transparent conductive film or transparent conductive sheet excellent in pen sliding durability in the vicinity, and a touch panel using the same.

  A transparent conductive film in which a transparent thin film with low resistance is laminated on a substrate made of a transparent plastic film is used for applications utilizing the conductivity, for example, a flat such as a liquid crystal display or an electroluminescence (EL) display. Widely used in electrical and electronic fields such as panel displays and transparent electrodes for touch panels.

  In recent years, along with miniaturization of portable information terminals, digital video cameras, digital cameras, and the like, cases in which a touch panel is mounted on a display in order to omit operation keys are increasing. However, these recording media are desired to be downsized and the display display itself to have a large screen. Therefore, the housing area (frame) surrounding the display is narrower, and a narrower frame is desired for the touch panel. Further, the vicinity of the frame is not in the housing and is present on the display area.

  When a pen is input on the touch panel, the transparent conductive thin film on the fixed electrode side and the transparent conductive thin film on the movable electrode (film electrode) side are in contact with each other. Strong bending stress due to load is applied. For this reason, there is a demand for a transparent conductive film excellent in pen sliding durability in the vicinity of the frame, in which the transparent conductive thin film does not break, such as cracking or peeling, even when a strong bending stress is applied due to a pen load. However, the conventional transparent conductive film has the following problems.

A transparent conductive film in which a transparent conductive thin film is formed on a substrate made of a transparent plastic film having a thickness of 120 μm or less and bonded to another transparent substrate with an adhesive layer has been proposed (for example, Patent Document 1). See). Although the touch panel using the transparent conductive film having such an adhesive layer satisfies the pen sliding durability in the vicinity of the frame of the touch panel described later, the pen input load (hereinafter referred to as the ON load) when used as a touch panel. ) Is heavy, it is difficult to recognize whether or not pen input is possible. Furthermore, when this technique is used, foreign matter is mixed in the manufacturing process, particularly the bonding process, the yield of the product is reduced, and the manufacturing cost is increased. Therefore, the touch panel cannot satisfy the recent market demand for cost reduction of the touch panel.
Japanese Patent Laid-Open No. 2-66809

Further, a transparent conductive film has been proposed in which a base layer formed by hydrolysis of an organosilicon compound is provided on a substrate made of a transparent plastic film, and a crystalline transparent conductive thin film is further laminated (for example, , See Patent Documents 2-7).
JP 60-131711 A JP-A 61-79647 JP-A-61-183809 Japanese Patent Laid-Open No. 2-194943 JP-A-2-276630 JP-A-8-64034

  However, these transparent conductive films are very fragile, and there is a problem that cracks occur in the transparent conductive thin film after a pen sliding durability test near the touch panel frame described later.

On the other hand, a transparent conductive film in which an amorphous transparent conductive thin film is provided on a substrate made of a transparent plastic film via a cured product layer has been proposed (see, for example, Patent Document 8). However, in order to improve the adhesion between the cured product layer and the transparent conductive thin film, a touch panel using a transparent conductive film produced by surface-treating the cured product layer with an acid or an alkaline aqueous solution is provided at the center of the touch panel. Although the pen writing property was improved, the pen sliding property in the vicinity of the frame was insufficient.
Japanese Patent Laid-Open No. 11-224539

  That is, in view of the above-described conventional problems, the object of the present invention is excellent in pen sliding durability (edge durability) in the vicinity of a frame when used in a touch panel, and in particular, using a polyacetal pen, To provide a transparent conductive film or a transparent conductive sheet, and a touch panel using the same, in which the transparent conductive thin film is not destroyed even after 10,000 sliding tests at a load of 2.5 N in the vicinity of the frame .

  This invention was made | formed in view of the above situations, Comprising: The transparent conductive film, the transparent conductive sheet, and touch panel which were able to solve said subject are as follows.

That is, the first invention in the present invention is a transparent conductive film in which a transparent conductive thin film containing a metal oxide as a constituent component is laminated via a cured product layer on a substrate made of a transparent plastic film, The transparent conductive thin film is amorphous, and the carbon concentration contained in the transparent conductive thin film is 1 × 10 ²⁰ to 1 × 10 ²² (atoms / cm ³ ). It is a film.

  According to a second invention, the metal oxide is an indium-tin composite oxide, and the ratio of the content of tin to indium is 15 to 60% by mass. It is a conductive film.

  According to a third invention, there is provided at least two layers having different refractive indexes between the transparent conductive thin film and the cured product layer, and the transparent conductive material according to the first or second invention, It is a film.

  A fourth invention is characterized in that the cured product layer contains particles, and the center line average roughness (Ra) of the transparent conductive thin film surface is 0.1 to 0.5 μm. It is a transparent conductive film in any one of.

  A fifth invention is the transparent conductive film according to any one of the first to fourth inventions, wherein a hard coat layer is laminated on the surface opposite to the transparent conductive thin film surface.

  A sixth invention is the transparent conductive film according to the fifth invention, wherein the hard coat layer has an antiglare property.

  A seventh invention is the transparent conductive film according to the fifth or sixth invention, wherein the hard coat layer is subjected to a low reflection treatment.

  An eighth invention is characterized in that a transparent resin sheet is bonded to an opposite surface of the transparent conductive film according to any one of the first to seventh inventions via an adhesive. It is a transparent conductive sheet.

  A ninth invention is a touch panel in which a pair of panel plates having the transparent conductive thin film are arranged via a spacer so that the transparent conductive thin film faces each other, and at least one of the panel plates is the first to eighth inventions. A touch panel comprising the transparent conductive film or the transparent conductive sheet according to any one of the above.

The transparent conductive film of the present invention has a configuration in which a transparent conductive thin film containing a metal oxide as a main constituent component is laminated on a substrate made of a transparent plastic film via a cured product layer, and the transparent conductive film By using a transparent conductive thin film that is amorphous and has a carbon concentration of 1 × 10 ²⁰ to 1 × 10 ²² (atoms / cm ³ ) contained in the transparent conductive thin film as a thin film, Adhesive strength with the resulting substrate can be improved, and mechanical strength against bending can be improved. Therefore, when a pen sliding test is performed in the vicinity of the touch panel frame, peeling and cracking are less likely to occur in the transparent conductive thin film, and the pen sliding durability in the vicinity of the frame can be improved.

  Further, by setting the ratio of tin content to indium in the transparent conductive thin film at 15 to 60% by mass, when the pen sliding test is performed on the transparent conductive thin film, the abrasion resistance of the transparent conductive thin film is improved. Can be improved. Therefore, the pen sliding durability at the center of the touch panel can be improved. In addition, by setting the center line average roughness (Ra) of the transparent conductive thin film surface to 0.1 to 0.5 μm, it is possible to achieve both pen sliding durability and prevention of Newton rings when a touch panel is used. it can.

  The substrate made of a transparent plastic film used in the present invention is a film obtained by subjecting an organic polymer to melt extrusion or solution extrusion, and stretching, cooling, and heat setting in the longitudinal direction and / or the width direction as necessary. is there. Organic polymers include polyethylene, polypropylene, polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, nylon 6, nylon 4, nylon 66, nylon 12, polyimide, polyamideimide, polyethersulfan, polyetheretherketone , Polycarbonate, polyarylate, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyether imide, polyphenylene sulfide, polyphenylene oxide, polystyrene, syndiotactic polystyrene, norbornene-based polymer, and the like.

  Among these organic polymers, polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, syndiotactic polystyrene, norbornene polymer, polycarbonate, polyarylate and the like are preferable. These organic polymers may be copolymerized with a small amount of other organic polymer monomers, or may be blended with other organic polymers.

  The thickness of the substrate made of the transparent plastic film used in the present invention is preferably in the range of more than 10 μm and not more than 300 μm, particularly preferably the upper limit is 260 μm and the lower limit is 70 μm. When the thickness of the plastic film is 10 μm or less, the mechanical strength is insufficient, and especially when used for a touch panel, there is a tendency to increase the deformation with respect to pen input, and the durability tends to be insufficient. On the other hand, when the thickness exceeds 300 μm, it is necessary to increase the pen load for deforming the film when used for a touch panel. Therefore, the load applied to the transparent conductive thin film inevitably increases, which is not preferable from the viewpoint of durability of the transparent conductive thin film.

  The substrate made of a transparent plastic film used in the present invention is a range that does not impair the purpose of the present invention, such as corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, ozone treatment, etc. A surface activation treatment may be performed.

  In the present invention, the adhesion between the substrate and the transparent conductive layer is improved, the pen input durability, the chemical resistance is imparted, and the precipitation of low molecular weight substances such as oligomers is prevented. You may provide the hardened | cured material layer which uses curable resin as a main structural component between thin film layers.

  The curable resin is not particularly limited as long as it is a resin that is cured by application of energy such as heating, ultraviolet irradiation, electron beam irradiation, etc., and silicone resin, acrylic resin, methacrylic resin, epoxy resin, melamine resin, polyester resin, urethane Resin etc. are mentioned. From the viewpoint of productivity, a curable resin containing an ultraviolet curable resin as a main component is preferable.

  Examples of such ultraviolet curable resins are synthesized from polyfunctional acrylate resins such as acrylic acid or methacrylic acid ester of polyhydric alcohol, diisocyanate, polyhydric alcohol and hydroxyalkyl ester of acrylic acid or methacrylic acid. Such polyfunctional urethane acrylate resins can be mentioned. If necessary, a monofunctional monomer such as vinyl pyrrolidone, methyl methacrylate, or styrene can be added to these polyfunctional resins for copolymerization.

  In order to improve the adhesion between the transparent conductive thin film and the cured product layer, it is effective to surface-treat the cured product layer. As a specific method, using a discharge treatment method irradiating glow or corona discharge, a method for increasing carbonyl group, carboxyl group, hydroxyl group, a chemical treatment method using acid or alkali treatment, an amino group, And a method of increasing polar groups such as a hydroxyl group and a carbonyl group.

  The ultraviolet curable resin is usually used by adding a photopolymerization initiator. As the photopolymerization initiator, known compounds that absorb ultraviolet rays and generate radicals can be used without any particular limitation. Examples of such photopolymerization initiators include various benzoins, phenyl ketones, and benzophenones. And the like. The addition amount of the photopolymerization initiator is preferably 1 to 5 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin.

  The concentration of the resin component in the coating solution can be appropriately selected in consideration of the viscosity according to the coating method. For example, the proportion of the total amount of the ultraviolet curable resin and the photopolymerization initiator in the coating solution is usually 20 to 80% by mass. Moreover, you may add other well-known additives, for example, leveling agents, such as a silicone type surfactant and a fluorine type surfactant, to this coating liquid as needed.

  In the present invention, the prepared coating solution is coated on a substrate made of a transparent plastic film. The coating method is not particularly limited, and conventionally known methods such as a bar coating method, a gravure coating method, and a reverse coating method can be used.

  Moreover, it is preferable that the thickness of a hardened | cured material layer is the range of 0.1-15 micrometers. The lower limit of the thickness of the cured product layer is more preferably 0.5 μm, and particularly preferably 1 μm. Further, the upper limit value of the thickness of the cured product layer is more preferably 10 μm, and particularly preferably 8 μm. When the thickness of the cured product layer is less than 0.1 μm, it is difficult to form a sufficiently cross-linked structure, so that pen input durability and chemical resistance are likely to be lowered, and adhesion due to low molecular weight such as oligomers is reduced. A decrease is also likely to occur. On the other hand, when the thickness of the cured product layer exceeds 15 μm, the productivity tends to decrease.

In the present invention, the metal oxide constituting the transparent conductive thin film is not particularly limited as long as it is a material having both transparency and conductivity, but indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, Examples thereof include tin-antimony composite oxide, zinc-aluminum composite oxide, indium-zinc composite oxide, silver or silver alloy, copper or copper alloy, and gold. Of these, indium-tin composite oxides are preferable from the viewpoints of environmental stability and circuit processability. In addition, the transparent conductive thin film used in the present invention contains a metal oxide as a main component, but carbon is contained at a concentration of 1 × 10 ²⁰ to 1 × 10 ²² (atoms / cm ³ ) as other components. Yes. In addition, components other than metal oxides and carbon may be contained in an amount of 5% by mass or less, more preferably 3% by mass or less, and particularly preferably 1% by mass or less as long as the effects of the present invention are not impaired. .

  The layer structure of the transparent conductive thin film may be a single layer structure or a laminated structure of two or more layers. In the case of a transparent conductive thin film having a laminated structure of two or more layers, the metal oxides constituting each layer may be the same or different.

  The thickness of the transparent conductive thin film is preferably in the range of 4 to 100 nm, particularly preferably the lower limit is 5 nm and the upper limit is 50 nm. When the film thickness of the transparent conductive thin film is less than 4 nm, it is difficult to form a continuous thin film, and it is difficult to obtain good conductivity. On the other hand, when the film thickness of the transparent conductive thin film is thicker than 100 nm, the transparency is easily lowered and it is difficult to obtain a film having mechanical strength capable of withstanding bending stress in the vicinity of the frame of the touch panel. .

  As a method for forming a transparent conductive thin film in the present invention, a vacuum vapor deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, and the like are known. Can be used as appropriate.

  For example, in the case of the sputtering method, a normal sputtering method using an oxide target, a reactive sputtering method using a metal target, or the like is used. At this time, oxygen, nitrogen, or the like may be introduced as a reactive gas, or means such as ozone addition, plasma irradiation, or ion assist may be used in combination. In addition, a bias such as direct current, alternating current, and high frequency may be applied to the substrate as long as the object of the present invention is not impaired.

  In the present invention, the purpose of using an amorphous film as the transparent conductive thin film is to prevent stress from concentrating on a local area such as a crystal, an amorphous interface or a crystal interface of the transparent conductive thin film, and a pen sliding test. This is to suppress the occurrence of cracks in the conductive film due to bending stress in the film.

In order to obtain an amorphous transparent conductive thin film, the following two methods are effective.
(1) A method for lowering the temperature of a film serving as a substrate during film formation (2) A method for making it difficult to form a crystal structure by increasing the amount of a dopant such as tin with respect to indium

First, the method (1) will be described.
In the film-forming atmosphere in which moisture and organic impurities are removed as much as possible when forming the transparent conductive thin film, migration on the substrate (film) surface is likely to occur because the energy drop of the deposited particles is small. As a result, a transparent conductive film containing crystals in the transparent conductive thin film tends to occur. In order to obtain an amorphous transparent conductive thin film in such a film formation atmosphere, the temperature of the film as the substrate is lowered, and migration on the surface of the substrate (film) is performed when vapor deposition particles are deposited. There is an effect to make it difficult to occur.

  For example, when a transparent conductive thin film is formed on a film using a roll-up type apparatus by sputtering, the roll temperature in contact with the film back surface (the surface opposite to the transparent conductive thin film forming surface) is lowered. Thus, the temperature of the film serving as the substrate can be lowered.

  The temperature at which the transparent conductive thin film is formed on the transparent plastic film serving as the substrate is preferably -20 to 30 ° C. When the temperature at the time of film formation exceeds 30 ° C., crystals are easily formed in the transparent conductive thin film. On the other hand, when the temperature is lower than -20 ° C, the transparent plastic film becomes brittle.

  In order to control the roll temperature, a water channel is provided in the roll, and a temperature-adjusted heat medium may flow through the water channel. The heating medium is not particularly limited, but simple substances such as water, oil, ethylene glycol, propylene glycol, and mixtures thereof are suitable.

  Furthermore, in order to obtain an amorphous transparent conductive thin film in an atmosphere in which moisture and organic substances in the film forming atmosphere are removed as much as possible, the amount of dopant such as tin is increased with respect to indium. It is also an effective method to make it difficult to form a crystal structure. Specific examples of the dopant include Sn, Si, Ti, W, Zr, Hf, and Zn. Among these dopants, tin is preferably used as a dopant from the viewpoint of improving conductivity and film hardness.

  The amount of tin dopant relative to indium is preferably 15 to 60% by mass. If it is less than 15% by mass, the film hardness in an amorphous state is insufficiently improved, and a touch panel using such a transparent conductive film has insufficient pen sliding durability at the center of the touch panel. The transparent conductive thin film is scraped after the pen sliding test. Moreover, when it exceeds 60 mass%, electroconductivity will become inadequate and when it is going to maintain the electroconductivity which can be used as a touchscreen, the film thickness of a transparent conductive thin film must be thickened. Therefore, the transparency of the transparent conductive film tends to be lowered. When a touch panel is manufactured using such a transparent conductive film inferior in transparency, the visibility of the touch panel is lowered.

Moreover, in this invention, the objective which sets the carbon concentration in a transparent conductive thin film to 1 * 10 < ²⁰ > -1 * 10 < ²² > (atoms / cm < ³ >) is the adhesive force of the base material which consists of a transparent conductive thin film and a film. This is to obtain a transparent conductive thin film that is less susceptible to peeling and cracking against bending stress near the frame of the touch panel. When the carbon concentration in the transparent conductive thin film is less than 1 × 10 ²⁰ (atoms / cm ³ ), the effect of improving the adhesion between the transparent conductive thin film and the substrate becomes insufficient. On the other hand, it is technically difficult to obtain a transparent conductive thin film exceeding 1 × 10 ²² (atoms / cm ³ ).

In order to obtain a transparent conductive thin film having a carbon concentration of 1 × 10 ²⁰ (atoms / cm ³ ) or more in the transparent conductive thin film, water in the film forming atmosphere is removed as much as possible when forming the transparent conductive thin film. It is important to introduce a carbon-containing gas component in a fresh state.

  Examples of the gas component containing carbon include carbon monoxide, carbon dioxide, carbon tetrachloride, and methane. Among these, a gas containing only carbon and oxygen such as carbon monoxide and carbon dioxide is preferable.

  For example, in the case of forming a film by sputtering, after evacuating the pressure in the vacuum chamber to a vacuum degree of 0.0001 Pa or less before performing sputtering, an inert gas such as Ar and carbon such as oxygen and carbon dioxide. It is preferable to carry out sputtering by introducing a reactive gas containing hydrogen into a vacuum chamber, generating discharge in a pressure range of 0.01 to 10 Pa. The same applies to other methods such as vapor deposition and CVD.

  If moisture remains in the film formation atmosphere, hydrogen is taken into the transparent conductive thin film, and the growth of the network (for example, In-O-) of the transparent conductive thin film may stop. In this case, it becomes difficult for carbon to be taken into the transparent conductive thin film, and it becomes difficult to obtain a transparent conductive thin film having a specific carbon concentration. As a result, the adhesion between the transparent conductive thin film and the substrate made of film becomes insufficient, and the touch panel using such a transparent conductive film has reduced mechanical strength due to bending stress of the transparent conductive film, and the vicinity of the frame The pen sliding durability is likely to decrease.

  A transparent conductive film in which a transparent conductive thin film having a low carbon concentration in such a transparent conductive thin film is laminated has insufficient adhesion between the transparent conductive thin film and the substrate. When such a transparent conductive film is used for a touch panel, peeling or cracking is likely to occur in the transparent conductive thin film after performing a linear sliding test 10,000 times with a load of 2.5 N in the vicinity of the frame.

  Moreover, in order to reduce the moisture in the film formation atmosphere, it is an effective method to reduce the moisture by exposing the film to a vacuum in a vacuum chamber for performing sputtering or the like. Impurities such as moisture and organic matter in the film formation atmosphere can be further reduced by using a method of increasing the temperature of the roll in contact with the film during vacuum exposure, or a method of using film heating with an infrared heater. It becomes possible. The heat treatment temperature at this time is preferably in the range of 100 to 200 ° C. Below 100 ° C., the effect of reducing impurities such as moisture and organic matter tends to be insufficient, and at temperatures exceeding 200 ° C., it tends to be difficult to maintain the flatness of the film.

  Furthermore, it is an effective method to provide a cryocoil in the deposition chamber in order to remove moisture in the deposition atmosphere.

  In this way, by removing moisture in the film forming atmosphere as much as possible and introducing a gas containing carbon as a reactive gas, the transparent conductive film is amorphous and has a high carbon concentration in the transparent conductive thin film. A film is obtained. Therefore, when this transparent conductive thin film is used for a touch panel, a polyacetal pen (tip shape: 0.8 mmR) is used and a linear sliding test is performed 10,000 times near the frame with a load of 2.5 N. No deterioration of the transparent conductive thin film is observed.

  Furthermore, it is preferable to lower the carbon concentration in the thickness direction of the transparent conductive thin film from the film substrate side toward the inside of the transparent conductive thin film as long as the conductivity of the transparent conductive thin film does not deteriorate. More preferably, carbon atoms are localized only within 5 nm from the film substrate. Thus, by localizing the carbon concentration in the thickness direction of the transparent conductive thin film, the adhesion between the transparent conductive thin film and the substrate is improved, and it has the same conductivity as when no carbon atom is contained. A transparent conductive thin film can be obtained. The carbon concentration can be controlled by adjusting the flow rate of a gas containing carbon supplied as a reactive gas during film formation.

  Further, for the purpose of changing the transmittance, color, and reflectance of the transparent conductive film, it is preferable to provide at least two layers having different refractive indexes between the transparent conductive thin film and the cured product layer. For example, when two layers having different refractive indexes are provided, a layer having a refractive index of 1.60 to 2.50 and a layer having a refractive index of 1.30 to 1.60 are laminated from the transparent plastic film side. It is preferable to do.

A layer having a refractive index of 1.60 or more and 2.50 or less is a layer made of an inorganic substance, a mixture of an organic substance and an inorganic substance. As the inorganic substance, transparent metal oxides such as In ₂ O ₃ , TiO ₂ , and Nb ₂ O ₅ are generally used.

  The layer made of a mixture of an organic substance and an inorganic substance contains a cured resin and metal oxide by ionizing radiation and has a refractive index in the range of 1.60 to 1.80 (hereinafter, this layer is referred to as a high refractive layer). When the refractive index of the said layer is less than 1.60, it becomes difficult to obtain a transparent conductive film excellent in antireflection performance. Moreover, when the refractive index of the said layer exceeds 1.80, it becomes difficult to form a layer. The preferred refractive index has a lower limit of 1.70 and an upper limit of 1.80.

  The metal oxide is not particularly limited as long as a layer having a refractive index in the range of 1.60 to 1.80 can be obtained. In order to further improve the transmittance of the transparent conductive film. It is preferable that the adhesiveness with the layer provided thereon is excellent. From this point, the metal oxide is not particularly limited as long as the above conditions are satisfied. For example, when the low refractive layer is a siloxane-based polymer, antimony-doped tin oxide (ATO), tin oxide Etc. can be mentioned preferably. These metal oxides may be used individually by 1 type, and may be used in combination of 2 or more type.

The layer having a refractive index of 1.30 or more and 1.60 or less is also made of an organic material, an inorganic material, or a mixture of an organic material and an inorganic material. In general, transparent metal oxides such as SiO ₂ and Al ₂ O ₃ are used as the inorganic substance.

  The organic material includes at least one of siloxane-based polymer, polyurethane, polyester, and acrylic from the viewpoint of adhesion to the transparent conductive thin film, and has a refractive index in the range of 1.30 to 1.55. Some are preferred. When the refractive index is out of the range, it becomes difficult to obtain a transparent conductive film having excellent color display properties.

  Moreover, it is preferable to contain particles so that the cured product layer has a center line average roughness (Ra) in the range of 0.1 to 0.5 μm for the purpose of preventing the generation of Newton rings when a touch panel is used. . When Ra is less than 0.1, it is difficult to prevent the occurrence of Newton rings. On the other hand, when Ra exceeds 0.5 μm, the surface of the transparent conductive thin film becomes too rough, and the pen sliding durability tends to deteriorate.

  The particles to be contained in the cured product layer are not particularly limited, but inorganic particles (for example, silica, calcium carbonate, etc.), heat resistant organic particles (for example, silicon particles, PTFE particles, polyimide particles, etc.), crosslinked polymer particles Examples include crosslinked PS particles and crosslinked acrylic particles. The average particle size (by electron microscopy) of these particles is preferably 0.5 to 5 μm. Moreover, it is preferable that content of the particle | grains contained in a hardened | cured material layer shall be 0.01-10 mass%.

  In addition, in order to further improve the scratch resistance of the outermost layer (pen input surface) when it is used as a touch panel, the surface opposite to the surface on which the transparent conductive thin film of the transparent plastic film is formed (the most when the touch panel is used). It is preferable to provide a hard coat layer on the pen input surface of the outer layer. The hard coat layer preferably has a pencil hardness of 2H or more. When the hardness is less than 2H, the hard coat layer of the transparent conductive film is insufficient in terms of scratch resistance.

  The thickness of the hard coat layer is preferably 0.5 to 10 μm. If the thickness is less than 0.5 μm, the scratch resistance tends to be insufficient, and if it is thicker than 10 μm, it is not preferable from the viewpoint of productivity.

  The curable resin composition used for the hard coat layer is preferably a resin having an acrylate functional group, such as a relatively low molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd. Examples thereof include oligomers or prepolymers such as (meth) acrylates of polyfunctional compounds such as resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols.

  Reactive diluents include monofunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone, and polyfunctional monomers such as trimethylolpropane tri (meth) acrylate. , Hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) ) Those containing a relatively large amount of acrylate, neopentyl glycol di (meth) acrylate, etc. can be used.

  In the present invention, it is preferable to mix urethane acrylate as an oligomer and dipentaerythritol hexa (meth) acrylate as a monomer.

  Moreover, as a curable resin composition used for the hard coat layer, a mixture of polyester acrylate and polyurethane acrylate is particularly suitable. Polyester acrylate has a very hard coating and is suitable as a hard coat layer. However, a coating film of polyester acrylate alone has a problem that it has low impact resistance and tends to be brittle. Therefore, in order to give impact resistance and flexibility to the coating film, it is preferable to use polyurethane acrylate together. That is, by using polyurethane acrylate together with polyester acrylate, the coating film can have functions of impact resistance and flexibility while maintaining the hardness as a hard coat layer.

  The blending ratio of both is preferably 30 parts by mass or less of the polyurethane acrylate resin with respect to 100 parts by mass of the polyester acrylate resin. When the blending ratio of the polyurethane acrylate resin exceeds 30 parts by mass, the coating film becomes too soft and the impact resistance tends to be insufficient.

  The curing method of the curable resin composition may be a normal curing method, that is, a method of curing by heating, electron beam or ultraviolet irradiation. For example, in the case of electron beam curing, 50 to 1000 keV emitted from various electron beam accelerators such as a Cockloft Walton type, a handicograph type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type. Preferably, an electron beam having an energy of 100 to 300 keV is used. In the case of ultraviolet curing, ultraviolet rays emitted from light rays such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp can be used.

  Furthermore, in the case of ionizing radiation curing, it is preferable to include a photopolymerization initiator or a photosensitizer in the curable resin composition. Examples of the photopolymerization initiator include acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide, and thioxanthones. Moreover, as a photosensitizer, n-butylamine, triethylamine, tri-n-butylphosphine, etc. are preferable.

In order to impart antiglare properties to the hard coat layer, it is effective to disperse inorganic particles such as CaCO ₃ and SiO ₂ in the curable resin, or to form an uneven shape on the surface of the hard coat layer. . For example, in order to form unevenness, after applying a coating liquid containing a curable resin composition, a surface-shaped film having a convex shape is laminated, and ultraviolet rays are irradiated on the shaped film to curable resin. After curing, it is obtained by peeling only the shaped film.

  The moldable film has a desired convex shape on a base film such as polyethylene terephthalate (hereinafter abbreviated as PET) having releasability, or a fine film on a base film such as PET. What formed the convex layer etc. can be used. Formation of the convex layer can be obtained, for example, by coating on a base film using a resin composition comprising inorganic particles and a binder resin.

As the binder resin, for example, an acrylic polyol cross-linked with polyisocyanate can be used, and as the inorganic particles, CaCO ₃ , SiO ₂ or the like can be used. In addition, mat-type PET in which inorganic particles such as SiO ₂ are kneaded at the time of PET production can also be used.

  When this shaped film is laminated on a coating film of an ultraviolet curable resin and then the coating film is cured by irradiating with ultraviolet rays, when the shaping film is a PET-based film, the ultraviolet light has a short wavelength side. There is a drawback that the UV curable resin is absorbed and insufficiently cured. Therefore, it is necessary to use a moldable film that is laminated on the UV curable resin coating film having a total light transmittance of 20% or more.

  Moreover, in order to further improve the visible light transmittance when used in a touch panel, a low reflection treatment may be performed on the hard coat layer. In this low reflection treatment, a material having a refractive index different from that of the hard coat layer is preferably laminated in a single layer or two or more layers.

In the case of a single layer structure, it is preferable to use a material having a refractive index smaller than that of the hard coat layer. In the case of a multilayer structure of two or more layers, a material having a higher refractive index than that of the hard coat layer is used for the layer adjacent to the hard coat layer, and the upper layer has a lower refractive index. It is better to choose the material. The material constituting such a low reflection treatment is not particularly limited as long as the above refractive index relationship is satisfied, whether it is an organic material or an inorganic material. For example, it is preferable to use a dielectric such as CaF ₂ , MgF ₂ , NaAlF ₄ , SiO ₂ , ThF ₄ , ZrO ₂ , Nd ₂ O ₃ , SnO ₂ , TiO ₂ , CeO ₂ , ZnS, In ₂ O ₃ . .

  This low reflection treatment may be a dry coating process such as a vacuum deposition method, a sputtering method, a CVD method, or an ion plating method, or a wet coating process such as a gravure method, a reverse method, or a die method.

  Furthermore, prior to the lamination of the low reflection treatment layer, as a pretreatment, known surface treatments such as corona discharge treatment, plasma treatment, sputter etching treatment, electron beam irradiation treatment, ultraviolet irradiation treatment, primer treatment, and easy adhesion treatment are performed. It may be applied to the hard coat layer.

  Using the transparent conductive film of the present invention, a transparent conductive laminated resin sheet used for a fixed electrode of a touch panel is obtained by laminating with a transparent resin sheet via a surface on which a transparent conductive thin film is not formed and an adhesive. . That is, by changing the substrate of the fixed electrode of the touch panel from glass to a transparent resin sheet, a touch panel that is light and difficult to break can be produced.

  The pressure-sensitive adhesive is not particularly limited as long as it has transparency, but for example, an acrylic pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive and the like are suitable. The thickness of this pressure-sensitive adhesive is not particularly limited, but it is usually desirable to set it in the range of 1 to 100 μm. When the thickness of the pressure-sensitive adhesive is less than 1 μm, it is difficult to obtain adhesiveness having no practical problem, and a thickness exceeding 100 μm is not preferable from the viewpoint of productivity.

  The transparent resin sheet to be bonded via this pressure-sensitive adhesive is used for imparting mechanical strength equivalent to that of glass, and the thickness is preferably in the range of 0.05 to 5 mm. When the thickness of the transparent resin sheet is less than 0.05 mm, the mechanical strength is insufficient as compared with glass. On the other hand, when the thickness exceeds 5 mm, it is too thick to be used for a touch panel. Moreover, the material similar to the said transparent plastic film can be used for the material of this transparent resin sheet.

  FIG. 1 shows an example of a touch panel using the transparent conductive film of the present invention. This is a touch panel in which a pair of panel plates having a transparent conductive thin film are arranged via a spacer so that the transparent conductive thin film faces each other, and the transparent conductive film of the present invention is used for one panel plate. Is.

  This touch panel can detect the position of the pen on the touch panel when the characters are input with the pen and the transparent conductive thin films facing each other come into contact with each other due to the pressure from the pen. it can. By detecting the pen position continuously and accurately, characters can be recognized from the pen trajectory. At this time, when the movable electrode on the pen contact side uses the transparent conductive film of the present invention, since the pen sliding durability is excellent, a stable touch panel can be obtained over a long period of time.

  In addition, sectional drawing of the plastic touch panel which does not use a glass substrate obtained using the transparent conductive film and transparent conductive sheet of this invention was shown in FIG. Since this plastic touch panel does not use glass, it is very lightweight and does not break due to impact.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. The performance of the transparent conductive film, the crystallinity of the transparent conductive thin film, and the pen sliding durability test of the touch panel were measured by the following methods.

(1) Light transmittance and haze Based on JIS-K7105, light transmittance and haze were measured using NDH-1001DP by Nippon Denshoku Industries Co., Ltd.

(2) Surface resistivity It measured by the 4-terminal method based on JIS-K7194. As a measuring machine, Lotest AMCP-T400 manufactured by Mitsubishi Yuka Co., Ltd. was used.

(3) Color (a value, b value)
In accordance with JIS-K7105, color a and b values were measured with a standard light C / 2 using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., ZE-2000).

(4) Crystallinity of transparent conductive thin film A transparent conductive film sample piece was cut into a 300 μm × 300 μm square, and fixed to a sample holder of an ultramicrotome with the conductive thin film surface facing forward. Subsequently, a knife was placed at an extremely acute angle with respect to the film surface to such an extent that a section having a target observation site of 1 μm × 1 μm or more was obtained, and cutting was performed at a set thickness of 70 nm.

An observation field of 1 μm × 1 μm is secured on the conductive thin film surface side of this slice and there is no significant damage to the thin film, and an accelerating voltage of 200 kV is used with a transmission electron microscope (JEMOL, JEM-2010). The photograph was taken at an observation magnification of 50,000 times in the visual field. Particles having a diameter of 5 nm or more observed as a region having a high electron density in the field of view were counted as crystal particles, and the average number of particles in 10 fields of view was defined as the number of crystal particles made of metal oxide (number / μm ² ).

(5) Pen sliding durability test in the vicinity of the frame A 2.5 N load is applied to a polyacetal pen (tip shape: 0.8 mmR) at a position 1.5 mm away from the inside of the bonding part of the touch panel. A linear sliding test of 10,000 times (round trip 5000 times) was performed on the touch panel. The sliding distance at this time was 30 mm, and the sliding speed was 60 mm / second. Furthermore, the gap between the upper and lower substrates of the touch panel was 150 μm. After this sliding durability test, first, it was visually observed whether the sliding portion was whitened. Further, the vicinity of the sliding portion was observed with a microscope to observe whether cracks were generated. Furthermore, the ON resistance (resistance value when the movable electrode (film electrode) and the fixed electrode were in contact) when the sliding portion was pressed with a pen load of 1.0 N was measured.

(6) Pen sliding durability test A 2.5 N load was applied to a polyacetal pen (tip shape: 0.8 mmR), and a linear sliding test was performed 100,000 times (50,000 round trips) on the touch panel. . The sliding distance at this time was 30 mm, and the sliding speed was 60 mm / second. After this sliding durability test, first, it was visually observed whether the sliding portion was whitened. Furthermore, a symbol “o” of 20 mmφ was written so as to be applied to the sliding portion with a pen load of 0.5 N, and it was evaluated whether the touch panel could be read accurately. Furthermore, the ON resistance (resistance value when the movable electrode (film electrode) and the fixed electrode were in contact) when the sliding portion was pressed with a pen load of 0.5 N was measured.

(7) Adhesive force measurement A 40 μm-thick ionomer film was laminated to a 75 μm-thick polyethylene terephthalate film using a polyester-based adhesive to produce a laminate for measuring an adhesive force. The ionomer surface of this laminate for measuring adhesive force and the transparent conductive thin film surface of the transparent conductive film were opposed to each other and heat sealed at 130 ° C. The laminate was peeled from the laminate for measuring adhesive force and the transparent conductive film by a 180 ° peeling method, and this peeling force was defined as the adhesive force. The peeling speed at this time was 1000 mm / min.

(8) Measurement of carbon concentration in transparent conductive thin film Secure a detection area of 140 μm x 224 μm on the surface of the conductive thin film, and use SIMS (PHI, 6650) using a primary acceleration voltage of 1 kV and Cs + primary ions. It was evaluated with. The carbon content in the film was derived by determining the relative sensitivity coefficient with a standard sample ion-implanted with a known carbon concentration. Furthermore, the hydrogen concentration in the transparent conductive thin film is also measured at the same time, and the depth at which the matrix effect (reduction in hydrogen concentration due to changes in the layer constituent materials) is defined is defined as the interface between the transparent conductive thin film and the substrate. The carbon concentration at the depth on the 2 nm transparent conductive thin film surface side from the interface was defined as the carbon concentration in the transparent conductive thin film.

(9) Surface Roughness A sample was brought into close contact with a glass plate, and in accordance with JIS B0601, using a two-dimensional surface roughness measuring machine (manufactured by Tokyo Seimitsu Co., Ltd., Surfcom 300B), cut-off 0.8, measurement length The centerline average roughness (Ra) was measured under the conditions of 4 mm, stylus load of 4 mN, and stylus speed of 0.3 mm / min.

Example 1
A mixed solvent of toluene / MEK (80/20: mass ratio) as a solvent in 100 parts by mass of a photopolymerization initiator-containing acrylic resin (manufactured by Dainichi Seika Kogyo Co., Ltd., Seika Beam EXF-01J), and a solid content concentration of 50 mass % And stirred to dissolve uniformly to prepare a coating solution.

The prepared coating solution was applied to a biaxially oriented transparent PET film (Toyobo Co., Ltd., A4340, thickness 188 μm) having an easy-adhesion layer on both sides using a Meyer bar so that the coating thickness was 5 μm. . After drying at 80 ° C. for 1 minute, the coating film was cured by irradiating with ultraviolet rays (light quantity: 300 mJ / cm ² ) using an ultraviolet ray irradiation device (UB042-5AM-W type, manufactured by Eye Graphics Co., Ltd.). . Next, heat treatment was performed at 180 ° C. for 1 minute to reduce volatile components.

  Moreover, in order to expose the biaxially oriented transparent PET film on which the cured product layer was laminated in a vacuum, a rewinding process was performed in a vacuum chamber. The pressure at this time was 0.002 Pa, and the exposure time was 20 minutes. The temperature of the center roll was 40 ° C.

Next, a transparent conductive thin film made of indium-tin composite oxide was formed on the cured product layer. At this time, the pressure before sputtering was 0.0001 Pa, and the target was indium oxide containing 36% by mass of tin oxide (manufactured by Sumitomo Metal Mining Co., Ltd., density: 6.9 g / cm ³ ). DC of ² W / cm ² Power was applied. Further, Ar gas was flowed at 130 sccm, O ₂ gas was flowed at 20 sccm, and CO ₂ gas was flowed at a flow rate of 20 sccm, and a film was formed by DC magnetron sputtering in an atmosphere of 0.4 Pa. However, in order to prevent arc discharge instead of normal DC, a pulse with a width of 5 μs was applied at a frequency of 50 kHz using an RPG-100 manufactured by Nippon NI. The center roll temperature was 10 ° C. and sputtering was performed.

  In addition, while constantly monitoring the oxygen partial pressure of the atmosphere with a sputtering process monitor (manufactured by LEYBOLD INFICON, XPR2), an oxygen gas flow meter and DC are used so that the degree of oxidation in the indium-tin composite oxide thin film becomes constant. I went back to power. As described above, a transparent conductive thin film made of an indium-tin composite oxide having a thickness of 22 nm was deposited.

<Production of touch panel>
This transparent conductive film is used as one panel plate, and the other panel plate is composed of an indium-tin composite oxide thin film (tin oxide content: 10% by mass) having a thickness of 20 nm by plasma CVD on a glass substrate. A transparent conductive thin film (Nippon Soda Co., Ltd., S500) was used. The two panel plates were arranged through epoxy beads having a diameter of 30 μm so that the transparent conductive thin film faced to prepare a touch panel.

Example 2
An indium-tin composite oxide thin film was formed in the same manner as in Example 1 except that a cryocoil (manufactured by Hakuto Co., Ltd., polycold) was provided in the film forming chamber and the flow rate of CO2 gas was 40 sccm. Furthermore, using this transparent conductive film, a touch panel was produced in the same manner as in Example 1.

Examples 3-4
Except for using an indium-tin composite oxide target with a tin oxide content of 20% by mass (Example 2) and 60% by mass (Example 3), the amount of oxygen introduced was set to an amount that minimizes the specific resistance value. A film was formed in the same manner as in Example 1. The tin oxide content in the indium-tin composite oxide thin film when using each target was 19% by mass (Example 2) and 59% by mass (Example 3), respectively.

Example 5
In Example 1, UV curing comprising a mixture of a polyester acrylate and a polyurethane acrylate as a hard coat layer resin on the opposite side of the cured product layer surface of the laminate comprising the base material / cured product layer comprising a biaxially oriented transparent PET film A mold resin (manufactured by Dainichi Seika Kogyo Co., Ltd., EXG) was applied by a gravure reverse method so that the film thickness after drying was 5 μm, and the solvent was dried. Then, it passed under a 160 W ultraviolet irradiation device at a speed of 10 m / min to cure the ultraviolet curable resin and form a hard coat layer. Next, heat treatment was performed at 180 ° C. for 1 minute to reduce volatile components.

  An indium-tin composite oxide thin film was formed in the same manner as in Example 1 on the cured product layer of the laminate comprising the hard coat layer / biaxially oriented transparent PET film and the substrate / cured product layer. Furthermore, using this transparent conductive film, a touch panel was produced in the same manner as in Example 1.

Example 6
In the same manner as in Example 1, a laminate composed of a substrate / cured material layer composed of a biaxially oriented transparent PET film was produced. On the surface opposite to the cured product layer surface of this laminate, a film thickness after drying an ultraviolet curable resin (EXG, manufactured by Dainichi Seika Kogyo Co., Ltd.) made of a mixture of polyester acrylate and polyurethane acrylate as a hard coat layer resin is 5 μm. Then, it was applied by a gravure reverse method and the solvent was dried. Thereafter, a PET film mat-shaped film (X, manufactured by Toray Industries, Inc.) having a fine convex shape formed on the surface was laminated so that the mat surface was in contact with the ultraviolet curable resin. The surface shape of this mat shaped film is an average surface roughness of 0.40 μm, an average crest distance of 160 μm, and a maximum surface roughness of 25 μm.

  The laminated film was passed under a 160 W ultraviolet irradiation device at a speed of 10 m / min to cure the ultraviolet curable resin. Next, the mat-shaped film was peeled off to form a hard coat layer having a concave shape on the surface and an antiglare effect. Next, heat treatment was performed at 180 ° C. for 1 minute to reduce volatile components.

  An indium-tin composite oxide thin film is formed on the cured product layer of the laminate comprising the antiglare hard coat layer / biaxially oriented transparent PET film / cured product layer in the same manner as in Example 1, and the transparent conductive layer is formed. Film was formed as a conductive thin film. Furthermore, a touch panel was produced in the same manner as in Example 1 using this transparent conductive film as one panel plate.

Example 7
In the same manner as in Example 5, a laminate comprising an antiglare hard coat layer / a substrate comprising a biaxially oriented transparent PET film / a cured product layer / a transparent conductive thin film layer was prepared, and then this antiglare hard coat was produced. TiO ₂ thin film layer (refractive index: 2.30, film thickness 15 nm), SiO ₂ thin film layer (refractive index: 1.46, film thickness 29 nm), TiO ₂ thin film layer (refractive index: 2.30, An antireflection treatment layer was formed by laminating a film thickness of 109 nm) and a SiO ₂ thin film layer (refractive index: 1.46, film thickness of 87 nm). In order to form a TiO ₂ thin film layer, titanium was used as a target, the degree of vacuum was 0.27 Pa, and Ar gas was flowed at a flow rate of 500 sccm and O ₂ gas was flowed at a flow rate of 80 sccm by a direct current magnetron sputtering method. Further, a cooling roll having a surface temperature of 0 ° C. was provided on the back surface of the substrate to cool the transparent plastic film. At this time, a power of 7.8 W / cm ² was supplied to the target, and the dynamic rate was 23 nm · m / min.

In order to form the SiO ₂ thin film, silicon was used as a target, and the degree of vacuum was 0.27 Pa, Ar gas was flowed at a rate of 500 sccm, and O ₂ gas was flowed at a flow rate of 80 sccm by a direct current magnetron sputtering method. Further, a 0 ° C. cooling roll was provided on the back surface of the substrate to cool the transparent plastic film. At this time, a power of 7.8 W / cm ² was supplied to the target, and the dynamic rate was 23 nm · m / min. Furthermore, a touch panel was produced in the same manner as in Example 1 using this transparent conductive film as one panel plate.

Example 8
The transparent conductive film produced in the same manner as in Example 1 was attached to a polycarbonate sheet having a thickness of 1.0 mm via an acrylic adhesive to produce a transparent conductive laminated sheet. Using this transparent conductive laminated sheet as a fixed electrode, the transparent conductive film of Example 6

Example 9
A TiO ₂ -containing acrylic hard coating agent [manufactured by JSR Corporation, trade name “Desolite Z7252D”, solid content concentration 45 mass%, TiO ₂ : acrylic resin = 75: 25 (mass ratio)], solid content concentration 3 A coating agent was prepared by diluting with a mixed solvent of methyl isobutyl ketone and isopropyl alcohol at a mass ratio of 1: 1 so that the mass% was reached.
This coating agent was applied on the cured layer of hard coat / biaxially stretched PET film / cured layer prepared in the same manner as in Example 4 so that the thickness after complete curing was 70 nm, and 80 After drying at a temperature of 1 ° C. for 1 minute, this was irradiated with ultraviolet rays at a light intensity of 80 mJ / cm ² and cured to a half-cured state to form a highly refractive layer.

Further, a fluorine-containing siloxane-based coating agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X-12-2138H”, solid content concentration: 3 mass%) and a photopolymerization initiator-containing acrylic resin (Daiichi Seika Kogyo Co., Ltd.) Manufactured by Seika Beam EXF-01J) was added so that the total solid concentration was 6% by mass. This coating solution for forming a low refractive index layer was applied on the high refractive index layer so that the thickness after the heat treatment was 20 nm, and dried at 80 ° C. for 1 minute. Subsequently, ultraviolet rays were irradiated (light quantity: 300 mJ / cm ² ) using an ultraviolet ray irradiation device (UB042-5AM-W type, manufactured by Eye Graphics Co., Ltd.), and further heat-treated at 150 ° C. for 1 minute to have a refractive index of 1 A low refractive index layer of .48 was formed. Subsequently, the transparent conductive thin film layer was formed by the same method as Example 1, and the transparent conductive film was obtained. Further, using this transparent conductive film, a touch panel was produced in the same manner as in Example 1.

Example 10
A transparent conductive film was obtained in the same manner as in Example 8 except that the thicknesses of the high refractive layer and the low refractive layer were 90 nm and 45 nm, respectively. Further, using this transparent conductive film, a touch panel was produced in the same manner as in Example 1.

Example 11
When forming the cured product layer of Example 1, Tospearl 145 (manufactured by Toshiba Silicone) having an average particle size of 4.5 μm was added to 1 part by mass with respect to 100 parts by mass of the acrylic resin, and dispersed. The coating film was formed with a Mayer bar so that the thickness of the coating film was 4 μm. A transparent conductive film was produced in the same manner as in Example 1 on the cured layer thus formed. The center line average roughness (Ra) of the obtained transparent conductive thin film surface was 0.24 μm. Further, using this transparent conductive film, a touch panel was produced in the same manner as in Example 1. The occurrence of Newton rings was confirmed while pressing the film against the glass under a three-wavelength fluorescent lamp, but no Newton rings were observed.

Comparative Example 1
A transparent conductive film was produced in the same manner as in Example 1 except that the volatile component reduction process by heat treatment at 180 ° C. for 1 minute and vacuum exposure treatment for 10 minutes was omitted. Further, using this transparent conductive film, a touch panel was produced in the same manner as in Example 1.

Comparative Example 2
A transparent conductive film was produced in the same manner as in Example 1 except that the winding time was 5 minutes. Further, using this transparent conductive film, a touch panel was produced in the same manner as in Example 1.

Comparative Example 3
A transparent conductive thin film made of indium-tin composite oxide was formed on the cured product layer obtained in the same manner as in Example 1. At this time, the pressure before sputtering and 0.0001 Pa, indium oxide tin oxide as a target containing 10 mass% (Sumitomo Metal Mining Co., density 7.1 g / cm ³⁾ used to, the 2W / cm ² DC Power was applied. Further, Ar gas was flowed at a flow rate of 130 sccm and O ₂ gas was flowed at a flow rate of 10 sccm, and a film was formed using a DC magnetron sputtering method in an atmosphere of 0.4 Pa. However, in order to prevent arc discharge instead of normal DC, a pulse with a width of 5 μs was applied at a frequency of 50 kHz using an RPG-100 manufactured by Nippon NI. The center roll temperature was 50 ° C. and sputtering was performed. The transparent conductive film thus obtained was further heated to 200 ° C. in an oven and held for 5 minutes. Further, using this transparent conductive film, a touch panel was produced in the same manner as in Example 1.

  From the results of Tables 1 and 2, the transparent conductive film described in Examples 1 to 11 satisfying the scope of the present invention or the touch panel using the transparent conductive sheet is a polyacetal pen (tip shape: 0) in the vicinity of the frame. 8 mmR) and a sliding test of 10,000 times with a load of 2.5 N, no peeling or cracking occurred, and there was no abnormality in the ON resistance.

On the other hand, the conductive films of Comparative Examples 1 and 2 that did not sufficiently remove moisture in the film had a low carbon concentration in the transparent conductive thin film, and the touch panel using these conductive films was made of polyacetal near the frame. An abnormality occurred in the ON resistance after a load of 2.5 N was applied to the pen (tip shape: 0.8 mmR) and the sliding test was performed 10,000 times. Furthermore, when the pen sliding portion was evaluated with a microscope, peeling and cracking of the transparent conductive thin film were observed.
Moreover, the conductive film of Comparative Example 3 in which the transparent conductive thin film was crystalline had cracks in the transparent conductive thin film after the pen sliding test near the frame of the touch panel, and the ON resistance was abnormal.

  When the transparent conductive film or transparent conductive sheet of the present invention is used in a touch panel for pen input, it does not cause peeling, cracking, etc. even near the frame of the touch panel, and has excellent pen sliding durability, and Because it has excellent position detection accuracy and display quality, it can cope with the narrow frame of the touch panel, and the downsizing of the recording medium and the large display screen used in portable information terminals, digital video cameras, digital cameras, etc. It is particularly suitable as a highly demanded touch panel.

It is explanatory drawing of a touch panel using the transparent conductive film of this invention. It is explanatory drawing of the touch panel which does not use a glass substrate using the transparent conductive film of this invention.

Explanation of symbols

10: Transparent conductive film 11: Transparent plastic film (base material)
12: Cured layer 13: Transparent conductive thin film 14: Hard coat layer 20: Beads 30: Glass plate 40: Transparent conductive sheet 41: Adhesive 42: Transparent resin sheet

Claims (9)

A transparent conductive film in which a transparent conductive thin film containing a metal oxide as a constituent component is laminated on a substrate made of a transparent plastic film via a cured product layer, the transparent conductive thin film being amorphous, And the carbon concentration contained in a transparent conductive thin film is 1 * 10 < ²⁰ > -1 * 10 < ²² > (atoms / cm < ³ >), The transparent conductive film characterized by the above-mentioned.   2. The transparent conductive film according to claim 1, wherein the metal oxide is an indium-tin composite oxide, and a ratio of a content of tin to indium is 15 to 60 mass%.   The transparent conductive film according to claim 1, wherein at least two layers having different refractive indexes are provided between the transparent conductive thin film and the cured product layer.   The said hardened | cured material layer contains particle | grains and the centerline average roughness (Ra) of a transparent conductive thin film surface is 0.1-0.5 micrometer, Transparent in any one of Claims 1-3 characterized by the above-mentioned. Conductive film.   The transparent conductive film according to claim 1, wherein a hard coat layer is laminated on a surface opposite to the transparent conductive thin film surface.   The transparent conductive film according to claim 5, wherein the hard coat layer has an antiglare property.   The transparent conductive film according to claim 5, wherein the hard coat layer is subjected to a low reflection treatment.   A transparent conductive sheet, wherein a transparent resin sheet is bonded to the surface opposite to the transparent conductive thin film surface of the transparent conductive film according to claim 1 through an adhesive.   The transparent touch panel according to any one of claims 1 to 8, wherein at least one panel plate is a touch panel in which a pair of panel plates having the transparent conductive thin film are arranged via a spacer so that the transparent conductive thin film faces each other. A touch panel comprising a conductive film or a transparent conductive sheet.

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