JP4888604B2 - Transparent conductive laminated film - Google Patents

Description

  The present invention relates to a transparent conductive film in which at least one dielectric layer and a transparent conductive thin film layer are laminated in this order on at least one surface of a substrate made of a transparent plastic film. In particular, the present invention relates to a transparent conductive laminated film that is excellent in pen sliding durability and excellent in compatibility with etching ink when patterning a transparent conductive thin film, so that the processing steps can be simplified and the environmental load can be reduced.

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

In recent years, with the widespread use of portable information terminals and notebook personal computers with touch panels, recently touch panels with superior pen sliding durability have been required. When a pen is input to 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 come into contact with each other. At this time, the transparent conductive thin film is cracked or peeled off by the pen load. There is a demand for a transparent conductive film having excellent pen sliding durability that does not break.
As means for improving pen sliding durability, there is a method in which the transparent conductive thin film on the movable electrode (film electrode) side is made crystalline (Patent Documents 1 to 4).

In such a touch panel, a transparent conductive thin film layer is used after being patterned.
Conventionally, patterning of a transparent conductive thin film layer has been performed by a photolithography method or a laser etching method. However, the photolithographic method requires a large-scale apparatus with a large number of steps, such as printing of photoresist on the portion where the transparent conductive thin film layer is left, light irradiation, immersion in acid, and subsequent immersion in an alkaline solution. Furthermore, waste liquid treatment such as acid and alkali is not preferable from the viewpoint of environmental problems.
On the other hand, although there is no problem of waste liquid treatment in the laser etching method, the equipment is large and the processing speed is slow, so that a large area treatment and a large number of patterning have caused practical problems.
Etching inks have been developed to solve the above problems (for example, ishipe HiperEch, manufactured by Merck). The characteristics of etching ink are simple processes (printing, heating, washing, drying) and reduction of environmental load.
Therefore, development of a transparent conductive film that can be used for etching ink is desired.

JP 2000-144379 A JP 2000-238178 A JP 2004-71171 A International Publication WO2000 / 051139

  That is, an object of the present invention is to provide a transparent conductive laminated film excellent in pen sliding durability and excellent in compatibility with etching ink in view of the above-mentioned conventional problems.

This invention is made | formed in view of the above situations, Comprising: The transparent conductive laminated film which was able to solve said subject consists of the following structures.
1. A laminated film in which at least one dielectric layer and a transparent conductive thin film layer are laminated in this order on at least one surface of a substrate made of a transparent plastic film, and the thickness of the dielectric layer is 3 to 100 nm . When forming a transparent conductive thin film layer mainly composed of crystalline indium oxide on at least one surface of a transparent plastic film substrate, the ratio of moisture pressure to inert gas in the film formation atmosphere during sputtering is 8.0 × 10 ^{−4 to} 3.0 × 10 ⁻³ , oxygen partial pressure is set to 8.0 × 10 ⁻³ to 30 × 10 ⁻³ Pa, and the film temperature is set to 80 ° C. or less during film formation A transparent conductive thin film layer is formed on the transparent plastic film, the thickness of the transparent conductive thin film is 10 to 100 nm, and the transparent conductive thin film layer has a tin oxide content of 0.5 to 0.5. 8 quality % A is indium - a tin composite oxide, the average crystal grain diameter of 30 to 1000 nm, and the ratio of the amorphous portion to the crystalline portion of the transparent conductive thin film is 0.00 to 0.50 A transparent conductive laminated film characterized by
2. 2. The transparent conductive laminated film according to 1 above, wherein the transparent conductive thin film layer is not heat-treated after film formation.

  The transparent conductive laminated film of the present invention has a structure in which at least one dielectric layer and a transparent conductive thin film layer are laminated in this order on at least one surface on a substrate made of a transparent plastic film. In addition to excellent dynamic durability, the transparent conductive thin film layer can be easily patterned with etching ink.

It is explanatory drawing of the transparent conductive laminated film of this invention.

<Crystal morphology and characteristics of indium oxide in transparent conductive thin film layer>
In the transparent conductive laminated film of the present invention, at least one dielectric layer and a transparent conductive thin film layer mainly composed of crystalline indium oxide are laminated on at least one surface on a transparent plastic film substrate. A transparent conductive laminated film, wherein the transparent conductive thin film layer has an indium oxide average crystal grain size of 30 to 1000 nm, and the ratio of the amorphous part to the crystalline part of the transparent conductive thin film layer is 0.00 ~ 0.50.

Here, the definition of the average crystal grain size of crystalline indium oxide and indium oxide of the transparent conductive thin film is as follows.
When the transparent conductive thin film layer is observed under a transmission electron microscope, the one having a polygonal region is defined as crystalline indium oxide. Further, the polygonal region is made of indium oxide crystal grains, and the area of all crystal grains is obtained. The value obtained by doubling the square root of the value obtained by dividing the area of the crystal grain by the circumference ratio π is defined as the crystal grain size. The average grain size is calculated from the grain size of all the grains.
The ratio of the amorphous part to the crystalline part of indium oxide in the transparent conductive thin film layer is calculated from the area ratio of the crystalline part and the amorphous part when observed under a transmission electron microscope. In addition, when the transparent conductive thin film layer is observed under a transmission electron microscope, the crystalline portion of indium oxide of the transparent conductive thin film layer is defined as a crystalline portion of indium oxide having a polygonal region, The remaining part is defined as an amorphous part.

  The average crystal grain size of indium oxide in the transparent conductive thin film layer in the present invention is 30 to 1000 nm. Especially preferably, it is 35-800 nm. When the average crystal grain size is smaller than 30 nm, the pen sliding durability is deteriorated because the bonding force between the crystal grains is weak. On the contrary, when the average crystal grain size exceeds 1000 nm, the bending resistance deteriorates, so that the flexibility is lowered and the meaning of forming the transparent conductive thin film layer on the plastic film substrate is remarkably lost.

The ratio of the amorphous part to the crystalline part of indium oxide in the transparent conductive thin film layer in the present invention is 0.00 to 0.50, preferably 0.00 to 0.45. When the ratio is larger than 0.50, the crystal grains are in an island shape in the amorphous part. In such a state, when the pen sliding durability test is performed, the amorphous part is first peeled off, and the crystal grain is also peeled off using the part as a trigger, and the transparent conductive thin film layer is destroyed.
If the ratio is 0.50 or less, the crystal grains are not floating in the form of islands in the amorphous part, and the crystal grains are all connected. In such a state, even if the pen sliding durability test is performed, the crystal grains support each other, so that a pen sliding durability is extremely high.

  Furthermore, since the transparent conductive laminated film according to the present invention has at least one dielectric layer between the transparent conductive thin film layer and the base made of the transparent plastic film, the etching ink and the transparent plastic film base are Since there is no direct contact, the etching ink can be easily removed in the cleaning process.

<Method for forming transparent conductive thin film layer>
As a method for forming a transparent conductive thin film layer in the transparent conductive laminated film of the present invention, the following methods [1] and [2] are desirable.
[1] In a method of forming a transparent conductive thin film layer mainly composed of crystalline indium oxide on at least one surface on a transparent plastic film substrate, The ratio is 8.0 × 10 ^{−4 to} 3.0 × 10 ⁻³ , the oxygen partial pressure is 8.0 × 10 ⁻³ to 30 × 10 ⁻³ Pa, and the film temperature is 80 ° C. during film formation. It is desirable to form a transparent conductive thin film layer on the transparent plastic film while maintaining the following.

It is known that when water is contained in the film formation atmosphere, the transparent conductive thin film layer is inhibited from being crystallized. Therefore, the amount of moisture in the film formation atmosphere is an important factor. In order to control the amount of water when forming a film on a plastic film, it is desirable to actually observe the amount of water during film formation. Using the ultimate vacuum to control the amount of water in the film formation atmosphere is inappropriate as described below.
First, when a film is formed on a plastic film by sputtering, the film is heated and the amount of water in the film forming atmosphere increases, which is higher than the amount of water when the ultimate vacuum is measured.

  The second point is the case of an apparatus that puts a large amount of transparent plastic film. In such an apparatus, the film is loaded by a roll. When a film is rolled and put into a vacuum chamber, water easily escapes from the outside of the roll, but water does not easily escape from the inside of the roll. When the ultimate vacuum is measured, the film roll is stopped, but the film roll travels during film formation, so that the inner part of the roll containing a lot of water is unwound, so moisture in the film formation atmosphere The amount increases and exceeds the amount of water when the ultimate vacuum is measured. In the present invention, in controlling the amount of moisture in the film forming atmosphere, the ratio of the water pressure to the inert gas in the film forming atmosphere during sputtering is measured.

The ratio of the moisture pressure to the inert gas in the film formation atmosphere during sputtering is desirably as low as possible. However, in an apparatus in which a large amount of transparent plastic film is introduced into the film formation chamber, the ratio to the inert gas as described in Patent Document 11 is used. In order to make the water pressure ratio 2.5 × 10 ^{−6 to} 7.0 × 10 ⁻⁴ , it is necessary to carry out a vacuum for a long time or a highly efficient vacuum pump is required, which is economical. Implementation becomes difficult.

The present invention has a crystalline part in the ratio of moisture pressure to inert gas that can be easily realized even in an apparatus that puts a large amount of transparent plastic film into a film forming chamber, and has excellent pen sliding durability. I found a manufacturing method. The ratio of the moisture pressure to the inert gas is 8.0 × 10 ^{−4 to} 3.0 × 10 ⁻³ that can be easily realized. In this state, when a film is formed with an oxygen partial pressure of 8.0 × 10 ⁻³ to 30 × 10 ⁻³ Pa, a transparent conductive thin film layer having a crystalline portion can be formed, and extremely excellent pen sliding durability A transparent conductive laminated film having the above can be obtained.

The range of the oxygen partial pressure is very unique. In general, a transparent conductive thin film layer is produced at an oxygen partial pressure at which the resistance value is lowest, but in the present invention, the film is formed at an oxygen partial pressure higher than that at which the resistance value is lowest. It is said.
The intention of increasing the oxygen partial pressure is as follows. When the film is formed with a high oxygen partial pressure, the oxygen deficient portion of indium oxide is compensated, so that a film having a crystal structure that is very energetically stable can be obtained.
As a result, the probability of generation of crystal grains on the transparent plastic substrate is increased, and further, crystal growth is facilitated, so that very excellent pen sliding durability is exhibited. However, if the oxygen partial pressure is higher than 30 × 10 ⁻³ Pa, the surface resistance exceeds a practical level, which is not desirable. Here, a practical level of surface resistance is about 50 to 1000 Ω / □.

  Further, it is desirable to form the transparent conductive thin film layer on the substrate while keeping the substrate temperature at 80 ° C. or lower during the film formation. When the temperature is higher than 80 ° C., a large amount of impurity gas such as water and organic gas is generated from the film. Therefore, the transparent conductive thin film layer having a crystalline part, that is, a transparent conductive thin film layer having excellent pen sliding durability Hinders film formation.

[2] In order to form a transparent conductive thin film layer mainly composed of crystalline indium oxide on at least one surface on a transparent plastic film substrate, an activation support method such as an ion assist method or an ion plating method is used. It is desirable to form a transparent conductive thin film layer on the film using a high power impulse magnetron sputtering method. In order to form crystal grains, the energy of evaporated atoms is necessary.

In the above method, the energy of the evaporated atom is larger than that of the normal film formation method, so the probability of crystal grain generation and the crystal growth are facilitated. To do. The film formation conditions were as follows: oxygen was introduced at 4.0 × 10 ^{−3 to} 6.0 × 10 ⁻² Pa, argon gas was introduced to bring the film formation pressure to 0.15 Pa, discharge voltage 80 V, Hearth potential It is desirable to perform arc discharge at + 40V and a discharge current of 120A.

  In the production method [1], [2] of the transparent conductive laminated film of the present invention, after laminating the transparent conductive thin film layer in order to control the size of the average crystal grain size, in an atmosphere containing oxygen, 80 to You may perform the heat processing of 200 degreeC and 0.1-12 hours heat processing. When the heating temperature and time are increased, crystal grains grow. Since the crystal grains do not grow at a temperature lower than 80 ° C., it does not contribute to improvement of pen sliding durability. If the temperature is higher than 200 ° C., it becomes difficult to maintain the flatness of the transparent plastic film, and further, the crystal grains grow too much, and a large stress is generated between the crystal grains, so that the pen sliding durability is deteriorated.

The transparent conductive thin film layer of the present invention is mainly composed of indium oxide and desirably contains 0.5 to 8% by mass of tin oxide. Tin oxide is equivalent to impurity addition to indium oxide. Due to the addition of tin oxide impurities, the melting point of indium oxide containing tin oxide increases. That is, the addition of tin oxide impurities acts in the direction of inhibiting crystallization. As for tin oxide, it is desirable to contain 0.5-8 mass%. When tin oxide is less than 0.5%, crystallization occurs, but the total light transmittance is lower than a practical level, and the surface resistance is higher than a practical level, which is not desirable. When tin oxide is larger than 8% by mass, crystallization is difficult and pen sliding durability is deteriorated.
The total light transmittance of the transparent conductive laminated film of the present invention is preferably 70 to 95%, and the surface resistance is preferably 50 to 1000 Ω / □.

  In the present invention, the thickness of the transparent conductive thin film layer is preferably 10 to 100 nm. When the thickness of the transparent conductive thin film layer is less than 10 nm, the film becomes non-uniform, and the pen sliding durability becomes weak. Moreover, since the total light transmittance will become lower than a practical level when the thickness of a transparent conductive thin film layer becomes thicker than 100 nm, it is not desirable.

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 formed by forming an organic polymer into a film by melt extrusion or solution extrusion into a film, and if necessary, stretching in the longitudinal direction and / or the width direction, A film that has been fixed and heat-relaxed. 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.

  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 20-250 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 layer 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 base material made of the transparent plastic film used in the present invention mainly includes a curable resin for the purpose of improving adhesion with a high refractive index 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 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 dielectric 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.

(Dielectric layer)
Examples of the dielectric layer that can be used in the present invention include SiO ₂ , Al ₂ O ₃ , TiO ₂ , Nb ₂ O ₅ , ZrO ₂ , Ta ₂ O ₅ , SiO _2, and complex oxides thereof. Among these, transparent metal oxides such as SiO ₂ and Al ₂ O ₃ having a low refractive index and composite metal oxides such as SiO ₂ —Al ₂ O ₃ are preferable.

  The film thickness of the dielectric layer is 3 to 100 nm, preferably 5 to 70 nm. Particularly preferably, the thickness is 10 to 60 nm for the purpose of improving the transmittance of the transparent conductive laminated film or making the patterning of the transparent conductive thin film layer difficult to see. When the film thickness is less than 3 nm, it becomes a discontinuous film, and the etching ink reacts with the transparent plastic film substrate or the cured product layer and cannot be removed during cleaning. On the other hand, when the film thickness exceeds 100 nm, the stress of the dielectric layer increases, and cracks are likely to occur in the transparent conductive thin film layer after patterning.

  As a method for forming a dielectric layer in the present invention, a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, and the like are known, and the above-described method is performed according to a required film thickness. Although it can be used as appropriate, the sputtering method is preferable from the viewpoint of reducing variations in film thickness. In general, when forming by sputtering, a reactive DC or AC sputtering method is used. Impedance control for controlling the reactive gas flow rate so as to keep the voltage value of the DC or AC power source constant in order to improve the deposition rate, or the reactive gas flow rate so as to keep the emission intensity in the plasma of a specific element constant. A plasma emission method for controlling the pressure is used.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In addition, various measurement evaluation in an Example was performed with the following method.
(1) Total light transmittance Based on JIS-K7105, the total light transmittance was measured using NDH-1001DP by Nippon Denshoku Industries Co., Ltd.

(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) Film Thickness of Dielectric Layer and Transparent Conductive Thin Film Layer A film sample piece in which the dielectric layer and the transparent conductive thin film layer were laminated was cut into a size of 1 mm × 10 mm and embedded in an epoxy resin for an electron microscope. This was fixed to a sample holder of an ultramicrotome, and a cross-sectional thin section parallel to the short side of the embedded sample piece was produced. Next, in a section where the thin film of this section is not significantly damaged, a transmission electron microscope (manufactured by JEOL, JEM-2010) is used to obtain a photograph at an acceleration voltage of 200 kV and a bright field at an observation magnification of 10,000 times. The film thickness was determined from the photograph taken.

(4) Average crystal grain size A film sample piece on which a transparent conductive thin film layer was laminated was cut into a size of 1 mm × 10 mm, 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 having no significant damage was selected, and a photograph was taken at an acceleration voltage of 200 kV and a direct magnification of 40000 times.
When a transparent conductive thin film layer is observed under a transmission electron microscope, a crystal grain is defined as one having a polygonal region, and the area of the crystal grain is obtained. The value obtained by doubling the square root of the value obtained by dividing the area of the crystal grain by the circumference ratio π is defined as the crystal grain size. For the crystal grains of indium oxide observed in the transparent conductive thin film layer under a transmission electron microscope, all crystal grain sizes are calculated. The average value of all crystal grain sizes is defined as the average crystal grain size.

(5) Ratio of amorphous part to crystalline part The area of all the crystal grains of indium oxide observed and photographed on the transparent conductive thin film layer under the above transmission electron microscope was taken out, and the area observed and photographed The ratio of the amorphous part with respect to the crystalline part was calculated with the difference in area as the area of the amorphous part.

(6) Pen sliding durability test A transparent conductive laminated film is used as one panel plate, and the other panel plate is an indium-tin composite oxide thin film (tin oxide) having a thickness of 20 nm by plasma CVD on a glass substrate. The transparent conductive thin film (Nippon Soda Co., Ltd. product, S500) which consists of 10 mass%) was used. The two panel plates were arranged via epoxy beads having a diameter of 30 μm so that the transparent conductive thin film layers were opposed to each other, thereby manufacturing a touch panel. Next, a 5.0 N load was applied to a polyacetal pen (tip shape: 0.8 mmR), and a linear sliding test was performed 300,000 times (150,000 reciprocations) 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, 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. The ON resistance is desirably 10 kΩ or less.

(7) Patterning property Etching ink (Issipe Hiper Etch 04S manufactured by Merck) was applied in a pattern on the transparent conductive thin film layer. Subsequently, it was heated in an oven at 150 ° C. ± 2 ° C. for 20 minutes. Then, it wash | cleaned with water and air-dried, the removability of etching ink was evaluated visually, and also conduction | electrical_connection of the transparent conductive thin film layer was confirmed.
○ There is no residue of etching ink, it is transparent, and conduction can be obtained.
X There is a residue of etching ink, which is not transparent or transparent but does not provide conduction.

The transparent plastic film substrate used in Examples and Comparative Examples is a biaxially oriented transparent PET film (A4340, thickness 188 μm) having easy-adhesion layers on both sides. As a curable resin layer, 100 parts by mass of a photopolymerization initiator-containing acrylic resin (Daiichi Seika Kogyo Co., Ltd., Seika Beam EXF-01J) and a copolymerized polyester resin (Toyobo Co., Ltd., Byron 200, weight average molecular weight 18, 000) 3 parts by mass, and a solvent mixture of toluene / MEK (8/2: mass ratio) as a solvent is added so that the solid content concentration is 50% by mass and stirred to dissolve uniformly. This coating solution was prepared (hereinafter referred to as coating solution A). The prepared coating solution was applied using a Mayer bar so that the thickness of the coating film 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.). .

(Examples 1-7)
The method of [1] described above is employed as a method for obtaining a transparent conductive laminated film.
These examples were carried out under the conditions shown in Table 1 as follows. The ITO film shown in Table 1 corresponds to the transparent conductive thin film layer, and the SiO ₂ film corresponds to the dielectric layer.
The film was put into a vacuum chamber and evacuated. The longer the evacuation time, the lower the water pressure during film formation during sputtering. Therefore, the ratio of the water pressure to the inert gas in the film formation atmosphere during sputtering was controlled by changing the evacuation time.
After introducing oxygen, argon was introduced as an inert gas to bring the total pressure to 0.5 Pa.
In order to form the SiO ₂ thin film, the direct current magnetron sputtering method was performed using silicon as a target. Further, while constantly observing the voltage value during the film formation, the oxygen gas flow meter was footed back so that the voltage value was constant.
Subsequently, power is applied at a power density of 1 W / cm ^{2 to} an indium oxide sintered target containing tin oxide or an indium oxide sintered target containing no tin oxide on the SiO ₂ thin film, and transparent by a DC magnetron sputtering method. A conductive thin film layer was formed. The film thickness was controlled by changing the speed at which the film passed over the target. In addition, the ratio of the moisture pressure to the inert gas in the film formation atmosphere during sputtering was measured using a gas analyzer (manufactured by Inficon, Transpector XPR3).
The film on which the transparent conductive thin film layer was formed was subjected to the heat treatment and then subjected to the measurements shown in Table 1 (however, some were measured without the heat treatment). The measurement results are shown in Table 1.

(Comparative Examples 1-5)
A transparent conductive laminated film was prepared and evaluated in the same manner as in Example 1 under the conditions described in Table 1. The measurement results are shown in Table 1.

As shown in Table 1, the transparent conductive laminated films described in Examples 1 to 7 are excellent in patternability when the transparent conductive thin film layer is patterned using an etching ink, and are also slid after the pen sliding durability test. The moving part was transparent, the ON resistance was 10 kΩ or less, and very excellent pen sliding durability was obtained.
On the other hand, in Comparative Examples 1 and 2 where the film thickness of the dielectric layer is outside the predetermined range, the pen sliding durability test is excellent, but the etching ink does not peel off after the ITO patterning (Comparative Example 1), or the ITO film is cracked. (Comparative Example 2). Moreover, the transparent conductive laminated film described in Comparative Examples 3 to 5 in which the average crystal grain size and the ratio of the amorphous part to the crystalline part are not appropriate did not have excellent pen sliding durability.

  As described above, according to the present invention, at least one dielectric layer and a transparent conductive thin film layer are formed on at least one surface on a transparent plastic film substrate, and the average crystal grain size of the transparent conductive thin film layer is In addition, by controlling the ratio of the amorphous part to the crystalline part within the range described above, a transparent conductive laminated film having excellent pen sliding durability and excellent patterning property with etching ink is obtained. Since it can be produced, it is extremely effective for applications such as a touch panel for pen input.

10: Transparent conductive film 11: Transparent plastic film (base material)
12: Cured material layer 13: Dielectric layer 14: Transparent conductive thin film layer

Claims (2)

A laminated film in which at least one dielectric layer and a transparent conductive thin film layer are laminated in this order on at least one surface of a substrate made of a transparent plastic film, and the thickness of the dielectric layer is 3 to 100 nm . When forming a transparent conductive thin film layer mainly composed of crystalline indium oxide on at least one surface of a transparent plastic film substrate, the ratio of moisture pressure to inert gas in the film formation atmosphere during sputtering is 8.0 × 10 ^{−4 to} 3.0 × 10 ⁻³ , oxygen partial pressure is set to 8.0 × 10 ⁻³ to 30 × 10 ⁻³ Pa, and the film temperature is set to 80 ° C. or less during film formation. A transparent conductive thin film layer is formed on the transparent plastic film, the thickness of the transparent conductive thin film is 10 to 100 nm, and the transparent conductive thin film layer has a tin oxide content of 0.5 to 0.5. 8 quality % A is indium - a tin composite oxide, the average crystal grain diameter of 30 to 1000 nm, and the ratio of the amorphous portion to the crystalline portion of the transparent conductive thin film is 0.00 to 0.50 A transparent conductive laminated film characterized by The transparent conductive laminated film according to claim 1, wherein the transparent conductive thin film layer is not heat-treated after film formation.