JP5397557B2 - Method for producing transparent conductive film - Google Patents

Description

  The present invention relates to a transparent conductive film in which a transparent conductive thin film layer is laminated on a substrate made of a transparent plastic film, and a touch panel, a capacitive touch panel, electronic paper, an organic electroluminescence element, and a dye-sensitized type using these. The present invention relates to a solar cell and an electromagnetic wave absorption panel. In particular, when used as an electrode film for a resistive touch panel incorporated in a display body such as a liquid crystal display, the transparent conductive film capable of obtaining long-term reliability of the touch panel and the use thereof are used because of excellent pen sliding durability. Related to the touch panel. Furthermore, since it is excellent in electroconductivity when it uses as transparent electrodes, such as an electrostatic capacitance type touch panel, electronic paper, an organic electroluminescent element, a dye-sensitized solar cell, and an electromagnetic wave absorption panel, a favorable device can be produced.

  A transparent conductive film obtained by laminating a transparent thin film having a low resistance on a substrate made of a transparent plastic film is used for applications utilizing the conductivity, for example, a liquid crystal display, electroluminescence (EL may be abbreviated as EL). ) Widely used in electrical and electronic fields such as flat panel displays such as displays, electronic paper, organic electroluminescence displays, and transparent electrodes for touch panels.

  In recent years, touch panels are widely recognized as input interfaces, and in particular, mobile terminals such as mobile phones, game machines, digital video cameras, and digital cameras are increasingly equipped with touch panels on display displays in order to omit operation keys. A touch panel used for such a portable terminal is input with a pen or the like so as not to stain the display screen. For this reason, there is a demand for a transparent conductive film in which the transparent conductive thin film layer does not deteriorate even when input is repeated with a strong force locally with a pen or the like, and the input of the touch panel does not become difficult even after long-term use.

Furthermore, a transparent conductive film having a low resistance is required for transparent electrodes such as capacitive touch panels, electronic paper, organic electroluminescence elements, dye-sensitized solar cells, and electromagnetic wave absorbing panels.
However, the conventional transparent conductive film has the following problems.
Patent Document 1 discloses a transparent conductive film in which a transparent conductive thin film is formed on a transparent plastic film substrate having a thickness of 120 μm or less and bonded to another transparent substrate with an adhesive layer. However, using the polyacetal pen described in the pen sliding durability test described later, after a linear sliding test of 300,000 times with a load of 5.0 N, the transparent conductive thin film peeled off, and the pen input Durability was insufficient. For this reason, the whitening of the peeled portion has a problem that the display quality deteriorates when used for a display with a touch panel (see Patent Document 1).

In addition, a transparent conductive film in which a base layer generated by hydrolysis of an organosilicon compound is provided on a transparent plastic film substrate and a crystalline transparent conductive thin film is further laminated is proposed in Patent Documents 2 to 7, etc. (See Patent Documents 2 to 7).
However, these transparent conductive films are very fragile and use a polyacetal pen described in the pen sliding durability test described later, and after a 300,000 linear sliding test at a load of 5.0 N, the transparent conductive film is transparent. Cracks occur in the conductive thin film.

Further, a low-resistance transparent conductive film has been proposed (see Patent Document 8). However, the specific resistance before heat treatment is as high as ^{4 to} 6 × 10 ⁻⁴ Ω · cm, the crystal orientation directions are (222) and (440), and the transparent conductive thin film is formed on glass at 200 ° C. The conductivity was insufficient.

  On the other hand, a magnetron sputtering method that significantly improves the peak power density is disclosed. In this method, in magnetron sputtering, the discharge gas can be brought into a completely ionized state by controlling the rising of the applied pulse. For this reason, it has been reported that the ionization rate of the particles sputtered from the target is greatly improved, and the adhesion to the substrate and the denseness of the film can be improved (see Patent Document 9).

  In this method, the sputtering gas first enters a glow discharge, then an arc discharge state, and finally becomes a fully ionized state. However, in actuality, it may change from a fully ionized state to an arc discharge state. When an arc discharge occurs, there is a high possibility of damage to the product or target. For this reason, it is necessary to set a condition that does not change to the arc discharge state, but the condition differs depending on the target material, and it takes a lot of time to set the condition.

  That is, in view of the above-described conventional problems, the object of the present invention is excellent in pen sliding durability when used for a touch panel using a high-power magnetron sputtering method, and in particular, using a polyacetal pen. The object is to provide a transparent conductive film or a transparent conductive sheet in which the transparent conductive thin film is not destroyed even after 300,000 sliding tests at a load of 0.0 N, and a touch panel using these. Furthermore, it is providing the low resistance transparent conductive film which can be used as a capacitive touch panel or a transparent electrode for organic electroluminescence.

Japanese Patent Laid-Open No. 2-66809 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 JP 2000-238178 A US Patent No. 6,296,742

  That is, in view of the above-described conventional problems, the object of the present invention is to provide a transparent conductive film excellent in pen input durability when used as an electrode film for a touch panel incorporated in a mobile phone or a game machine, and the like. It is to provide a touch panel used. Furthermore, it is providing the transparent electrode excellent in electroconductivity which can be used for an electrostatic capacitance type touch panel, electronic paper, an organic electroluminescent element, a dye-sensitized solar cell, an electromagnetic wave absorption panel, etc.

This invention is made | formed in view of the above situations, Comprising: The manufacturing method of the transparent conductive film which was able to solve said subject consists of the following structures.
1. A method for producing a transparent conductive film in which a transparent conductive thin film layer of crystalline indium-tin composite oxide having a SnO2 content of 2 to 12% by mass is laminated on a substrate made of a transparent plastic film, A transparent conductive thin film layer is formed by heating a substrate made of a transparent plastic film at a heating temperature of 100 to 200 ° C. and exposing the substrate to vacuum at a degree of vacuum of 100 Pa or less and a film temperature of 0 to 200 ° C. for 1 to 100 minutes. Is produced using a high-power impulse magnetron sputtering method. A method for producing a transparent conductive film, comprising:
2. The transparent conductive thin film layer is a film made of a crystalline indium-tin composite oxide having a (222) orientation. The manufacturing method of the transparent conductive film of description.
3. The transparent conductive thin film layer is a film made of a crystalline indium-tin composite oxide having (400) orientation. The manufacturing method of the transparent conductive film of description.
4). The specific resistance of the transparent conductive thin film layer is 3.0 × 10 ⁻⁴ Ω · cm or less. ~ 3. The manufacturing method of the transparent conductive film in any one.
5. The transparent conductive thin film layer is produced at 150 ° C. or lower. ~ 4. The manufacturing method of the transparent conductive film in any one of.
6). A cured product layer mainly composed of an ultraviolet curable resin is provided on a substrate made of a transparent plastic film, and then heated at a heating temperature in the range of 100 to 200 ° C. 1. The transparent conductive thin film layer is produced using the high power impulse magnetron sputtering method after being exposed to vacuum in the film temperature range for 1 to 100 minutes. ~ 5. The manufacturing method of the transparent conductive film in any one of.

The transparent conductive film obtained by the present invention has a structure in which a transparent conductive thin film layer is laminated on a substrate made of a transparent plastic film, and the transparent conductive thin film layer is formed by using a high power impulse magnetron sputtering method. Since the film is formed, the ionization rate of the sputtered particles is high, and a dense and crystalline transparent conductive thin film can be obtained even when the film forming temperature is low. Therefore, when a pen sliding test is performed on the touch panel, there is an advantage that peeling and cracking are less likely to occur in the transparent conductive thin film, and pen sliding durability can be improved. Furthermore, since it is excellent in electroconductivity, it can be used as transparent electrodes, such as a capacitive touch panel.

Schematic of a high power magnetron sputtering apparatus. The electron diffraction pattern of the transparent conductive thin film obtained in Example 1 of this invention. The electron diffraction pattern of the transparent conductive thin film obtained by the comparative example 1 of this invention. The electron diffraction pattern of the transparent conductive thin film obtained in Example 2 of this invention.

The transparent conductive film obtained by this invention is a transparent conductive film which laminated | stacked the transparent conductive thin film layer on the base material which consists of a transparent plastic film. Hereinafter, each layer will be described in detail.

(Base material made of transparent plastic film)
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, polyethersulfane, polyetheretherketone , Polycarbonate, polyarylate, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyetherimide, 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.

  It is preferable that the thickness of the base material which consists of a transparent plastic film used by this invention is 10-300 micrometers, More preferably, it is 70-260 micrometers. If the thickness of the plastic film is less than 10 μm, the mechanical strength is insufficient, and handling in the pattern forming process of the transparent conductive thin film becomes difficult, which is not preferable. On the other hand, if the thickness exceeds 300 μm, the thickness of the touch panel becomes too thick, which is not suitable for mobile devices.

  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 addition, the substrate made of the transparent plastic film used in the present invention is provided with a curable resin for the purpose of improving adhesion with the transparent conductive thin film layer, imparting chemical resistance, and preventing precipitation of low molecular weight substances such as oligomers. You may provide the hardened | cured material layer made into a main structural component.

  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 layer and the cured product layer, it is effective to further treat the cured product surface. Specific methods include a discharge treatment method that irradiates glow discharge or corona discharge, a method of increasing carbonyl group, carboxyl group, hydroxyl group, a chemical treatment method of treating with acid or alkali, and 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, More preferably, it is 0.5-10 micrometers, Most preferably, it is 1-8 micrometers. When the thickness of the cured product layer is less than 0.1 μm, it becomes difficult to form a sufficiently cross-linked structure, so that chemical resistance is likely to be lowered, and adhesion due to low molecular weight such as oligomer is also liable to occur. . On the other hand, when the thickness of the cured product layer exceeds 15 μm, the productivity tends to decrease.

(Transparent conductive thin film layer)
In the present invention, the transparent conductive thin film layer is composed of indium oxide, tin oxide, zinc oxide, titanium oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, indium-zinc composite oxide, titanium. -Niobium complex oxide and the like. Of these, indium-tin composite oxide and indium-zinc composite oxide are preferable from the viewpoints of environmental stability and circuit processability.
For example, when an indium-tin composite oxide is used, the content of SnO2 is preferably 2 to 12% by mass. If the content of SnO2 is less than 2% by mass, the carrier density is insufficient and it is difficult to reduce the specific resistance. On the other hand, when the content of SnO2 exceeds 12% by mass, impurity scattering increases, so that the mobility is lowered and it is difficult to reduce the specific resistance.

  The thickness of the transparent conductive thin film is preferably in the range of 4 to 100 nm, particularly preferably 5 to 80 nm. When the thickness of the transparent conductive thin film is less than 4 nm, it tends to be difficult to form a continuous thin film and to exhibit good conductivity. On the other hand, when it is thicker than 100 nm, the stress of the transparent conductive thin film layer increases, warping of the transparent conductive film occurs, and it becomes difficult to produce a device such as organic electroluminescence.

In the present invention, the transparent conductive thin film is formed by a high power impulse magnetron sputtering method.
The high power impulse magnetron sputtering method is shown in FIG. 1 as a specific image. That is, in FIG. 1, the capacitor is charged from the DC power source by turning on the switch for a desired time, and the thyristor switch is turned on after the switch is turned off. At this time, the charge accumulated in the capacitor is applied to the cathode via the inductance, and sputtering is started by starting the discharge.
At this time, the transparent conductive thin film layer is formed by a sputtering method using an oxide target or a reactive sputtering method using a metal target. It is preferable to use an oxide target from the viewpoint of production stability. 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.
The duty ratio of the power applied to the electrode (pulse applied power ON / OFF ratio, ON time / OFF time) is preferably 10% or less. More preferably, it is 3% or less.

For example, when an indium oxide target containing 10% by mass of SnO ₂ is used, specific conditions include a peak power density of 0.1 to 5 kW / cm ² , a pulse width of 10 to 200 μs, and a pulse frequency of 10 to 10. 500 Hz is mentioned.
When the peak power density is less than 0.1 kW / cm ^2, it is difficult to ionize the sputtered particles, and it is difficult to obtain a crystalline transparent conductive thin film. On the other hand, when the peak power density exceeds 5 kW / cm ² , it is sufficient for ionization of the sputtered particles, and the load on the cathode and the like becomes large, which is not preferable.
When the pulse width is less than 10 μs, the ionization of the sputtered particles hardly occurs, and it is difficult to obtain a crystalline transparent conductive thin film. On the other hand, if it exceeds 200 μs, the pulse period becomes irregular and arcing tends to occur, which is not preferable.
A pulse frequency of less than 10 Hz is not preferable because the film formation rate becomes too slow. On the other hand, if the pulse frequency exceeds 200 Hz, the thermal load on the target becomes too large and it is easy to break, which is not preferable.

  The temperature at which the transparent conductive thin film is formed on the transparent plastic film serving as the substrate is preferably −10 to 150 ° C. More preferably, it is -10-80 degreeC. When the temperature during film formation exceeds 150 ° C., the surface of the plastic film becomes soft, and the film surface is likely to be damaged during running of the vacuum chamber. Moreover, it becomes difficult to obtain a crystalline conductive thin film at a temperature lower than −10 ° C.

  As for the pressure at the time of film formation, it is preferable to perform sputtering by introducing an inert gas such as Ar and a reactive gas such as oxygen into a vacuum chamber, generating discharge in a pressure range of 0.01 to 10 Pa.

In order to improve the crystallinity of the transparent conductive thin film layer, it is effective to remove impurities such as moisture and organic matter in the film formation atmosphere.
For example, it is preferable to heat the transparent plastic film used as a board | substrate in the range of 100-200 degreeC of heat processing temperature. If it is less than 100 ° C., the effect of reducing volatile components tends to be insufficient, and if it exceeds 200 ° C., it tends to be difficult to maintain the flatness of the film.

It is also an effective means to reduce volatile components by exposing the film to a vacuum in a vacuum chamber for performing sputtering or the like. It is possible to further reduce the volatile components by increasing the temperature of the roll that comes into contact with the film during vacuum exposure, or by using film heating with an infrared heater.
The degree of vacuum at this time is preferably 1,000 Pa or less, and more preferably 100 Pa or less. At a pressure higher than 100 Pa, the effect of removing volatile components is not sufficient.
The vacuum exposure time is preferably 1 to 100 minutes. When the vacuum exposure time is less than 1 minute, the effect of removing volatile components is not sufficient. On the other hand, when the time exceeds 100 minutes, the productivity is remarkably lowered, which is industrially unsuitable.

  Furthermore, the volatile components can be reduced more efficiently by increasing the film temperature during vacuum exposure. As film temperature, the range of 0-200 degreeC is preferable, More preferably, it is the range of 20-180 degreeC.

In order to control the film temperature, it is effective to increase the roll temperature in contact with the film or to use the film heating with an infrared heater in combination. As roll temperature at this time, the range of 0-200 degreeC is preferable similarly to the said film temperature, More preferably, it is the range of 20-180 degreeC.
The infrared heater may be any of a near infrared type, a middle infrared type, and a far infrared type. The input power to the infrared heater is preferably in the range of 5 to 50,000 W / m ² · min. When the input power is less than 5 W · m ² / min, there is no effect of increasing the film temperature, and when the input power is higher than 50,000 W / m ² · min, the film temperature becomes too high and the flatness of the film is lowered. It is not preferable.

In order to improve the crystallinity of the transparent conductive thin film layer, the bottom made of an inorganic material such as CeO ₂ , TiO ₂ , crystalline In ₂ O ₃ ZrO ₂ , ZnO, SiN, AlN, SiO ₂ , Al ₂ O ₃ A stratum may be provided.

Further, in order to obtain a transparent conductive thin film having higher crystallinity, energy may be imparted by means such as heating and ultraviolet irradiation after film formation. Of these energy applying means, heat treatment in an oxygen atmosphere is preferable.
The heat treatment temperature is preferably in the range of 120 to 200 ° C. When the temperature is lower than 120 ° C., the effect of improving the film quality is sufficient. On the other hand, at temperatures exceeding 200 ° C., it becomes difficult to maintain the flatness of the film.
Moreover, as a heat processing time, the range for 0.2 to 60 minutes is suitable. If it is less than 0.2 minutes, even if the heat treatment is performed at a high temperature of about 220 ° C., the effect of improving the film quality is not sufficient, which is not preferable. On the other hand, heat treatment times exceeding 60 minutes are industrially unsuitable.
The atmosphere for the heat treatment is preferably performed in a space filled with oxygen after exhausting to a pressure of 0.2 Pa or less in advance. The pressure at this time is preferably not more than atmospheric pressure.

  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 layer, and the pen sliding durability test of the touch panel were measured by the following methods.

(1) Total light transmittance Based on JIS-K7136, light transmittance was measured using Nippon Denshoku Industries Co., Ltd. NDH-1001DP.
(2) Surface resistance value Based on JIS-K7194, it measured by the 4-terminal method. As a measuring machine, Lotest AMCP-T400 manufactured by Mitsubishi Yuka Co., Ltd. was used.

(3) Specific resistance measurement of transparent conductive thin film The specific resistance was calculated using the surface resistance value and the film thickness of the transparent conductive thin film layer.

(4) Crystal orientation of transparent conductive thin film layer (electron diffraction pattern)
A film sample piece laminated with a transparent conductive thin film layer was cut out and attached to the upper surface of an appropriate resin block with the conductive thin film surface facing outward. After trimming this, an ultrathin section approximately parallel to the film surface was prepared by a general ultramicrotome technique.
This section was observed with a transmission electron microscope (JEOL, JEM-2010), a conductive thin film surface portion not significantly damaged was selected, and an electron diffraction pattern was photographed under the conditions of an acceleration voltage of 200 kV and a camera length of 100 cm. The center of the electron diffraction pattern thus obtained was obtained, and the intensity profile in the radial direction was plotted. The crystal plane spacing contributing to the scattering was determined from the position of the peak appearing in the intensity profile.

(5) Pen sliding durability test A 5.0 N load was applied to a polyacetal pen (tip shape: 0.8 mmR), and a 300,000 (50,000 round trip) linear sliding test was performed 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.

[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, after a coating film was similarly provided on the opposite surface, a 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 set to 0.0001 Pa, and indium oxide containing 10% by mass of tin oxide as a target (Mitsui Metal Mining Co., Ltd., density 7.1 g / cm ³ ) was used, and the peak power density was 1 kW / It was applied so as to be in cm ^2. Further, Ar gas was flowed at 130 sccm and O ₂ gas was flowed at an O ₂ flow rate at which the surface resistance value was minimized, and a film was formed using a high power impulse magnetron sputtering method in an atmosphere of 0.4 Pa. However, in order to prevent arc discharge, a pulse of 50 μs width was applied at a cycle of 100 Hz using a Hüttinger (HMP2 / 3) capable of controlling power supply. The center roll temperature was 0 ° C. and sputtering was performed. In this way, a transparent conductive thin film layer made of an indium-tin composite oxide having a thickness of 20 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.

[Comparative Example 1]
A transparent conductive film was produced in the same manner as in Example 1 except that the power supply was changed to the DC magnetron sputtering method. Further, a touch panel was produced in the same manner as in Example 1.

[Example 2]
A transparent conductive film was produced in the same manner as in Example 1 except that the peak power density was 0.5 kW / cm ² . Further, a touch panel was produced in the same manner as in Example 1.

  From the results shown in Table 1, the touch panel using the transparent conductive film or transparent conductive sheet described in Examples 1 and 2 that satisfies the scope of the present invention is 5.0 N in a polyacetal pen (tip shape: 0.8 mmR). Even after 300,000 sliding tests were performed with the above load applied, no peeling or cracking occurred, and there was no abnormality in the ON resistance.

  On the other hand, the touch panel using the transparent conductive film or transparent conductive sheet described in Comparative Example 1 prepared by using a normal DC magnetron sputtering method is 5.0 N in a polyacetal pen (tip shape: 0.8 mmR). An abnormality occurred in the ON resistance after a load test was performed 300,000 times.

The transparent conductive film or transparent conductive sheet obtained by the present invention is excellent in pen sliding durability when used for a touch panel incorporated in a mobile terminal such as a mobile phone or a game machine, and therefore used for a long time. Can also reduce the pen input performance of the touch panel. Furthermore, since it is excellent in electroconductivity, it can be used as a transparent electrode for organic electroluminescence.

1: Sputtering power source 2: Capacitor 3: Switch 4: Thyristor 5: Thyristor 6: Coil 7: Magnetron cathode 8: Transparent plastic substrate 9: Vacuum chamber

Claims (6)

A method for producing a transparent conductive film in which a transparent conductive thin film layer of crystalline indium-tin composite oxide having a SnO2 content of 2 to 12% by mass is laminated on a substrate made of a transparent plastic film, A transparent conductive thin film layer is formed by heating a substrate made of a transparent plastic film at a heating temperature of 100 to 200 ° C. and exposing the substrate to vacuum at a degree of vacuum of 100 Pa or less and a film temperature of 0 to 200 ° C. for 1 to 100 minutes. Is produced using a high-power impulse magnetron sputtering method. A method for producing a transparent conductive film, comprising:   The method for producing a transparent conductive film according to claim 1, wherein the transparent conductive thin film layer is a film made of a crystalline indium-tin composite oxide having a (222) orientation.   2. The method for producing a transparent conductive film according to claim 1, wherein the transparent conductive thin film layer is a film made of a crystalline indium-tin composite oxide having (400) orientation. The specific resistance of the said transparent conductive thin film layer is 3.0 * 10 <^-4> ohm * cm or less, The manufacturing method of the transparent conductive film in any one of Claims 1-3 characterized by the above-mentioned.   The said transparent conductive thin film layer is produced at 150 degrees C or less, The manufacturing method of the transparent conductive film in any one of Claims 1-4 characterized by the above-mentioned. A cured product layer mainly composed of an ultraviolet curable resin is provided on a substrate made of a transparent plastic film, and then heated at a heating temperature in the range of 100 to 200 ° C., with a degree of vacuum of 100 Pa or less and 0 to 200 ° C. The transparent conductive film according to any one of claims 1 to 5, wherein the transparent conductive thin film layer is produced using a high power impulse magnetron sputtering method after being exposed to vacuum in a film temperature range for 1 to 100 minutes. A method for producing a film.