TW201413556A - Transparent conductive film, method for manufacturing transparent conductive film, and touch panel - Google Patents

Abstract

Provided is a transparent conductive film wherein transparent conductive sections, non-conductive sections, and wiring are appropriately protected, and at the same time, superb optical performance is produced. This transparent conductive film (20) is provided with the following: a transparent substrate (21); optical adjustment layers (22 and 23) provided on both surfaces of said transparent substrate; transparent conductive layers (8 and 9) provided on top of said optical adjustment layers; wiring (10 and 11) connected to said transparent conductive layers (8 and 9); and a protective layer (14) that covers a transparent conductive layer and wiring. Said protective layer (14) is between 1 and 50 [mu]m thick, inclusive. The parts of the transparent conductive film (20) where there is no wiring (10 or 11) have a transmission hue (b*) of 1.5 or less.

Description

Transparent conductive film, method of manufacturing transparent conductive film, and touch panel

The present invention relates to a transparent conductive film suitable for a capacitive touch panel, a method of manufacturing a transparent conductive film suitable for the production of the transparent conductive film, and a touch panel using the transparent conductive film.

In recent years, as an input device, a touch panel can be used. The touch panel is operable to operate the input device of the machine by touching the display portion on the display screen. As the touch panel, a resist film method, a capacitance method, or the like is known.

The resistive film method is a method in which two opposing resistive films are provided. When a voltage is applied to a single resistive film, when the resistive film is pressed, the pressed resistive film side contacts the opposing resistive film, and the voltage drop corresponding to the pressed position is detected. Thereby, the place where the operation is performed is detected.

The electrostatic capacitance method is a method of capturing a change in electrostatic capacitance between a portion of the electrostatic conductivity of the fingertip and the like and the conductive film, and detecting the position of the fingertip or the like. By arranging the transparent conductive portion and the non-conductive portion on the display screen, the position of the fingertip is detected from the change in electrostatic capacitance when the fingertip approaches the transparent conductive portion. Further, in the electrostatic capacitance method, by overlapping the transparent conductive films having different wiring shapes, it is possible to perform multi-point detection, and it is possible to realize a more intuitive operation.

In the touch panel as described above, an invisibility measure for making the shape of the transparent conductive portion and the non-conductive portion inconspicuous is required based on a design request or the like. Further, protection of the conductive film or wiring of the touch panel is required. In this case, optical characteristics such as total light transmittance, haze, and transmission hue b* are required.

For example, in a capacitive touch panel, a transparent conductive film oriented with a touch panel having improved visibility is proposed (see Patent Document 1).

Prior technical literature Patent literature

Patent Document 1 International Publication No. WO2006/126604

The touch panel of the electrostatic capacitance type does not form an invisible transparent conductive portion and a non-conductive portion, and protects the conductive portion of the transparent conductive film, the non-conductive portion, and the two-sided conductive film of the wiring portion.

Therefore, the present invention has been made to solve the above problems, and an object of the invention is to provide a transparent conductive film which is excellent in optical characteristics while appropriately protecting a transparent conductive portion, a non-conductive portion, and a wiring portion.

The transparent conductive film of the present invention comprises: a transparent substrate, an optical adjustment layer provided on both surfaces of the transparent substrate, a transparent conductive layer provided on each of the optical adjustment layers, a wiring connected to the transparent conductive layer, and at least a transparent conductive film Protection of one side and covered with transparent conductive layer and wiring Floor. The thickness of the protective layer is 1 μm or more and 50 μm or less. The first multilayer structure is formed by the substrate layer, the optical adjustment layer, the transparent conductive layer, and the protective layer, and the light transmission hue b* penetrating the first multilayer structure is 1.5 or less.

Moreover, the touch panel of the present invention includes the above-described transparent conductive film.

In the method for producing a transparent conductive film of the present invention, a transparent conductive portion and a non-conductive portion are formed on both surfaces of a transparent substrate to form a wiring portion connected to the transparent conductive portion, and a transparent conductive portion is formed on at least one surface of the transparent conductive film. Protective layer.

The transparent conductive film of the present invention can be formed by forming a protective layer on at least one surface, and when used in a touch panel, it can be protected from breakage caused by damage, and can also be formed by lowering the transmitted hue b*. Therefore, it is possible to provide a touch panel of the electrostatic capacitance type in which the conductive film surface is protected.

1‧‧‧Substrate

2, 3‧‧‧ hard coating

4, 5‧‧‧ high refractive index layer

6, 7‧‧‧ low refractive index layer

8, 9‧‧‧ transparent conductive layer

10, 11‧‧‧ wiring

12‧‧‧Transparent Conductive Parts

13‧‧‧Non-conducting department

14‧‧‧Protective layer

20‧‧‧Transparent conductive film

21‧‧‧Transparent substrate

22, 23‧‧‧ Optical adjustment layer

24‧‧‧Substrate

Fig. 1 is a schematic cross-sectional view showing an example of a transparent conductive film of the first embodiment.

Fig. 2 is a schematic cross-sectional view showing an example of a transparent conductive film according to a modification of the first embodiment.

Fig. 3 is a schematic plan view showing a transparent conductive film of the first embodiment.

Fig. 4 is a schematic cross-sectional view showing an example of a transparent conductive film of the second embodiment.

Fig. 5 is a schematic plan view showing a transparent conductive film of the second embodiment.

[Formation of the Invention]

Hereinafter, the transparent conductive film of the embodiment will be described.

(Embodiment 1)

Fig. 1 is a schematic cross-sectional view showing an example of a transparent conductive film of the first embodiment.

The transparent conductive film 20 includes a transparent substrate 21, optical adjustment layers 22 and 23 respectively provided on both surfaces of the transparent substrate 21, transparent conductive layers 8 and 9 respectively provided on the optical adjustment layers 22 and 23, and are respectively connected to the transparent conductive layer. The wirings 10 and 11 of 8, 9 are covered with the transparent conductive layer 8 and the protective layer 14 of the wiring 10 on one surface of the transparent conductive film 20.

In the present embodiment, the transparent substrate 21 is composed of the base material 1 and the hard coat layers 2 and 3 provided on both surfaces of the base material 1.

The substrate 1 is formed of a material having visible light transmittance. In the substrate, for example, (1) inorganic glass, (2) polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, poly Transparent of ethylene naphthalate, etc., polyamine (nylon 6, nylon 66, etc.), polyimide, polyarylate, polycarbonate, polyacrylate, polyethersulfone, polyfluorene, etc. Resin. Further, the substrate 1 may be such that the above-exemplified transparent resin has no extension. Extended plastic film. Further, the substrate 1 may be a composite film in which a plurality of materials are laminated.

Further, the thickness of the substrate 1 is preferably in the range of about 10 μm to 200 μm. However, in the transparent conductive film 20 of the present invention, the thickness of the substrate 1 is not limited by this range.

Further, one or both surfaces of the substrate 1 may be surface-treated. By performing the surface treatment, the layer of the layer can be strongly adhered to the surface of the substrate 1. In the surface treatment, for example, a method such as easy adhesion treatment, plasma treatment, corona treatment, ozone treatment, or the like can be used.

The hard coat layers 2 and 3 are provided on the surface of the substrate 1 to improve the mechanical strength, wear resistance, and the like of the substrate 1. As the material used for the hard coat layers 2 and 3, a material having visible light transmittance can be used. For example, (1) an acrylic resin such as an acrylate, an acrylamide, a methacrylate or a methacrylamide, (2) an organic fluorene resin, and (3) a thermosetting poly fluorene can be used. A transparent resin such as an oxyalkylene resin is used as the material of the hard coat layers 2 and 3.

The method of forming the hard coat layers 2 and 3 can be carried out by a film forming method that conforms to the material for forming the hard coat layers 2 and 3. The hard coat layers 2, 3, for example, can dissolve a main component such as the above-mentioned resin and an ultraviolet absorbing material in a solvent to prepare a coating liquid, using a pattern coater, a curtain flow coater, and a roll coater. Machine, reverse roll coater, gravure roll coater, knife coater, rod coater, spin coater, micro-groove roll coater, etc., apply the coating liquid on the substrate, by ultraviolet light The coating film is cured by irradiation or the like.

Further, the hard coat layer is preferably provided on both faces of the substrate 1. In this case, the stress in the front and back of the transparent conductive film 20 can be adjusted as symmetrically as possible by adjusting the film thickness of the hard coat layer in the watch. By adjusting the stress in the watch, the occurrence of deflection or the like can be suppressed, and the transparent electrode film 20 can be appropriately incorporated into the touch panel. However, the transparent substrate 21 may be formed of the base material 1 provided with only one hard coat layer, or the transparent substrate 21 may be formed of the base material 1 not provided with a hard coat layer.

Further, the thickness of the hard coat layers 2 and 3 is preferably in the range of about 1 μm to 10 μm. However, the thickness of the hard coat layers 2, 3 is not limited by the above range.

The transparent conductive layers 8, 9 may be formed of a material having visible light transmission and conductivity. As a material of the transparent conductive layers 8 and 9, for example, indium tin oxide (ITO: Indium Tin Oxide), zinc oxide, carbon nanotubes, graphene, nano silver, or conductive polymer resin (containing an ion-conducting mechanism) can be used. A fourth-order ammonium salt-based conductive monomer, a conductive fine particle having an electron conduction mechanism, a resin such as a π-conjugated conductive polymer, or the like).

Further, when ITO is used as the material of the transparent conductive layers 8 and 9, the optical thickness of the transparent conductive layers 8 and 9 is preferably in the range of 30 nm or more and 80 nm or less. When the optical film thickness of the transparent electrode layer 8 is thinner than 30 nm, the film thickness is thin and sufficient conductivity cannot be obtained. Further, when the optical thickness of the transparent conductive layers 8 and 9 is thicker than 80 nm, the transmittance of the obtained film is lowered, and the optical characteristics are lowered. However, in the transparent conductive film 20 of the present embodiment, when the thin film of ITO is patterned as described later to form the transparent conductive layers 8 and 9, the optical thickness of the transparent conductive layers 8 and 9 is not limited to the above range.

In the present embodiment, the transparent conductive layers 8 and 9 are formed by patterning the formed thin film into a predetermined shape after forming a thin film using a transparent conductive material. By the patterning, the non-conductive non-conductive portion 13 provided between the transparent conductive portion 12 and the adjacent transparent conductive portion 12 is formed in the transparent conductive layers 8 and 9. The transparent conductive portion 12 is a portion where the transparent conductive material remains after patterning, and the non-conductive portion 13 The portion of the transparent conductive material has been removed by patterning. For example, when the transparent conductive film 20 is used on the touch panel, the transparent conductive layers 8 and 9 are transparent electrodes of the touch panel. At this time, in the transparent conductive layer 8, a stripe-shaped transparent conductive portion 12 extending in a predetermined direction is provided, and in the transparent conductive layer 9, a stripe-shaped transparent conductive portion extending in a direction orthogonal to the specified direction is provided. 12.

Further, the optical adjustment layers 22 and 23 are used by sequentially laminating the high refractive index layers 4 and 5 and the low refractive index layers 6 and 7 from the transparent substrate 21 side. By layering layers having different refractive indices, the phases of the reflected light at the interfaces of the different layers are reversed and canceled, and the reflected light can be reduced. Therefore, the reflected light emitted from the side of the transparent substrate 21 can be reduced, and the visibility of the transparent conductive pattern electrode (the transparent conductive portion 12 of the transparent conductive layer 8) close to the observation side can be made difficult. As an example, in the present embodiment, the high refractive index layers 4 and 5 are metal oxide layers, and the low refractive index layers 6 and 7 are ruthenium oxide layers. Further, the high refractive index and the low refractive index in the "high refractive index layer and low refractive index layer" are those which distinguish the refractive index of one layer from the refractive index of the other layer by the relative size. That is, the refractive index of the high refractive index layer is relatively higher than the refractive index of the low refractive index layer. Further, since the reduced frequency band of the reflected light can be controlled by the refractive index of each layer and the optical film thickness, the physical film thickness of each layer can be appropriately optically designed and determined in accordance with the frequency band to be blocked. Further, the optical adjustment layers 22 and 23 may be composed of three or more layers.

For example, when the transparent substrate 1 and the hard coat layers 2 and 3 have a refractive index of 1.5 or more and 1.7 or less, and the transparent conductive layers 8 and 9 are made of a film of indium tin oxide (optical film thickness: 30 nm or more and 80 nm or less), By laminating a high refractive index layer (refractive index: 1.7 or more and 2.6 or less, optical film thickness: 5 nm or more and 25 nm or less) and a low refractive index layer (refractive index: 1.3 or more and 1.5 or less, optical film thickness: 50 nm or more and 100 nm or less) It can reduce the yellow tint characteristic of indium tin oxide under visible light. Examples of the combination of the material of the high refractive index layer and the low refractive index layer satisfying the above range include a high refractive index layer: ruthenium oxide (Nb ₂ O ₅ ), and a low refractive index layer: ruthenium oxide (SiO _X "x is A combination of the number of oxygen atoms"). As the material which can be used for the high refractive index layers 4 and 5, in addition to Nb ₂ O ₅ , ZnO, TiO ₂ , CeO ₂ , Sb ₂ O ₅ , SnO ₂ , Y ₂ O ₃ , La ₂ O ₃ , ZrO can also be exemplified. ₂ , Al ₂ O ₃ .

The method of forming the high refractive index layers 4 and 5 and the low refractive index layers 6 and 7 can be carried out by a film forming method conforming to a material for forming a high refractive index layer and a low refractive index layer. For example, physical vacuum evaporation (PVD), chemistry such as (1) coating method such as screen printing or inkjet printing, (2) magnetron sputtering method, EB vapor deposition method for irradiating an accelerated electron beam, or the like can be used. A gas phase film formation method such as vapor deposition (CVD) or the like. In particular, since the vapor phase film formation method can strictly control the film thickness and can be adjusted to a desired optical film thickness, it is preferred to use a vapor phase film formation method.

The wirings 10 and 11 are connected to the transparent conductive layers 8 and 9 at the peripheral portion of the transparent conductive film 20. The wirings 10 and 11 are disposed on the transparent conductive film 20, but do not overlap with the image display regions of the image display device combined with the transparent conductive film 20. In the transparent conductive film 20 of the present embodiment, the materials of the wirings 10 and 11 can be suitably selected from materials having conductivity and excellent workability. For example, a metal such as copper, silver or gold can be used as the material of the wirings 10 and 11.

Further, the thickness of the wirings 10 and 11 is preferably in the range of about 0.1 μm to 2 μm. However, the thickness of the wirings 10, 11 is not limited by this range.

The protective layer 14 is provided on one surface of the transparent electrode film 20 so as to cover the transparent conductive portion 12, the non-conductive portion 13, and the wiring 10. The protective layer 14 is used to protect the transparent conductive portion 12, the non-conductive portion 13, and the wiring 10. In the present embodiment, the protective layer 14 is provided only on one surface of the transparent conductive film 20. However, the protective layer 14 may be provided on both surfaces of the transparent electrode film 20. Further, by providing the protective layer 14, the difference in optical characteristics between the transparent conductive portion 12 and the non-conductive portion 13 can be reduced, so that the transparent conductive portion 12 and the non-conductive portion 13 can be made difficult to visually recognize.

The protective layer 14 is formed using a material having insulating properties and excellent film formability. For the material of the protective layer 14, for example, (1) an acrylic resin such as an acrylate, an acrylamide, a methacrylate or a methacrylamide, or (2) an organic fluorene resin, ( 3) a thermosetting polydecane resin, (4) cerium oxide or the like.

The thickness of the protective layer 14 is preferably about 1 μm or more and 50 μm or less. Further, the transmission hue b* of the protective layer 14 is preferably in the range of about -1.0 or more and 0.5 or less. The transparent electrode film of the unprotected layer 14 has a yellow hue as a whole due to the material constituting the transparent conductive layer 8, and the transmitted hue b* becomes large. Therefore, by providing the protective layer 14 having a slightly bluish tint in the range of -1.0 or more and 0.5 or less through the dye b*, the entire transparent conductive film 20 can be transmitted through the hue b* (without the portions of the wirings 10 and 11). The hue b*) is controlled below 1.5 to suppress the yellow tone. Furthermore, the so-called transmission hue b* means L*a* The b* color system (D65 light source, 2° field of view) indicates the b* when the color of the light is transmitted. However, the thickness of the protective layer 14 is not limited by this range. Further, the transmission hue b* of the protective layer 14 is more preferably -0.5 or more and 0 or less.

The method of forming the protective layer 14 can be carried out by a film forming method conforming to the material for forming the protective layer 14. The protective layer 14 can be prepared, for example, by dissolving a main component such as the above-mentioned resin and an ultraviolet absorbing material in a solvent to prepare a coating liquid, using a pattern coater, a curtain flow coater, a roll coater, and a reverse roll coater. a gravure roll coater, a knife coater, a bar coater, a spin coater, a micro-groove roll coater, etc., and the coating liquid is applied to the formed surface of the protective layer 14 and irradiated by ultraviolet rays. The film is formed by hardening the film. Alternatively, a separately formed film or the like as the protective layer 14 may be laminated on the conductive surface.

Fig. 2 is a schematic cross-sectional view showing an example of a transparent conductive film according to a modification of the first embodiment.

The transparent conductive film 20 of the modified example is different from the example shown in Fig. 1 in that the base material 24 of the transparent substrate 21 is a laminated body. The substrate 24 of the modification is a laminate of the film substrate 15 and the optical adhesive layer 17 and the film substrate 16 in this order. As the film base materials 15 and 16, a film formed of the same material as the above-described base material 1 can be used. As the optical adhesive layer 17, an acrylic resin, a polyoxymethylene resin, or a rubber-based resin can be used. Further, in the optical adhesive layer 17, an adhesive having a UV absorbing property or a film-like or liquid adhesive can be used. The thickness of the optical adhesive layer 17 is preferably in the range of about 1 μm to 150 μm. The transparent substrate 21 is formed by laminating the hard coat layers 2 and 3 on both surfaces of the substrate 24. Furthermore, the optical adjustment layers 22, 23 laminated on the transparent substrate 21 (high fold The luminosity layers 4 and 5, the low refractive index layers 6 and 7), the transparent conductive layers 8 and 9 (the transparent conductive portion 12 and the non-conductive portion 13), the wirings 10 and 11, and the protective layer 14 are as described in FIG. The same is true, and the description of the repetition is omitted.

Fig. 3 is a schematic plan view showing the transparent conductive film shown in Figs. 1 and 2.

The transparent conductive portion 12, the non-conductive portion 13, and the wiring portions 10, 11 are shielded from the outside by the protective layer 14, and are indicated by broken lines in Fig. 2 . The protective layer 14 is formed to cover the transparent conductive portion 12, the non-conductive portion 13, and the wiring portions 10, 11.

Here, in the transparent conductive film 20 shown in FIGS. 1 and 2, the first laminate including the transparent substrate 21, the optical adjustment layers 22 and 23, the transparent conductive layers 8 and 9 and the protective layer 14 is penetrated. The transmitted light phase b* of the structured light is 1.5 or less. In addition, the transmission hue b* refers to b* when the color of the transmitted light is expressed by the L*a*b* color system (D65 light source, 2° field of view). When the transmission hue b* of the first laminated structure portion (portion without the wirings 10, 11) of the transparent conductive film is larger than 1.5, the entire transparent conductive film has a yellow hue. If a transparent conductive film having a hue b* greater than 1.5 is used on the touch panel, the screen will have a yellow hue and the image quality will deteriorate. In order to suppress the color tone of the transparent electrode film 20, the light transmission b phase b* of the light penetrating the first laminate structure is preferably -3.0 or more. Further, the transmission hue b* of the first laminated structure is more preferably 0 or more and 1.0 or less. At this time, it is possible to further suppress the color tone of the transparent electrode film 20.

In addition, in order to make the transmission hue b* of the transparent conductive film 1.5 or less, for example, a laminate in which the protective layer 14 is two or more layers and a blue color may be used due to dryness. Also, it can also be used The protective layer 14 is formed by subjecting the entire protective layer 14 with a material of a blue tint material.

As described above, in the transparent conductive film 20 of the present embodiment, the protective layer 14 for protecting the transparent conductive portion 12, the non-conductive portion 13, and the wiring 10 is provided, but the first laminated structure (that is, the wirings 10 and 11 are not provided). Part of the transmission hue b* is suppressed to 1.5 or less. Therefore, according to the present embodiment, it is possible to realize a transparent electrode film which is excellent in optical characteristics while protecting the transparent conductive portion 12, the non-conductive portion 13, and the wiring 10.

The transparent conductive film 20 shown in FIGS. 1 and 2 can be used as a constituent member of the touch panel. By using the transparent conductive film 20, the scratch resistance and high transmittance can be improved by the protective layer 14. An electrostatic capacitance type touch panel which is excellent in optical characteristics such as high transparency and which is inconspicuous in the transparent conductive portions 8 and 9.

Hereinafter, a method of producing the transparent conductive film of the present invention will be described.

<Transparent conductive layer forming step>

First, a thin film of a material for forming the transparent conductive layers 8 and 9 is formed on the transparent substrate 21, and a transparent conductive portion 12 and a non-conductive portion 13 are formed by patterning the thin film.

If a film is formed using the forming materials of the transparent conductive layers 8, 9, a suitable film forming method can be used in accordance with the material for forming the transparent conductive layers 8, 9. For example, physical vacuum evaporation (PVD), chemistry such as (1) coating method such as screen printing or inkjet printing, (2) magnetron sputtering method, EB vapor deposition method for irradiating an accelerated electron beam, or the like can be used. A gas phase film formation method such as vapor deposition (CVD) or the like. In particular, using ITO for transparency When the material of the conductive portion is formed by a vapor phase film formation method, the charge density is increased and the conductivity tends to increase. Therefore, a vapor phase film formation method is preferably used.

For patterning of the thin film of the material forming the transparent conductive layers 8, 9, a suitable patterning method can be used according to the material for forming the transparent conductive layers 8, 9. For example, an etch mask corresponding to a desired pattern may be formed on the film, and the film may be patterned by immersion in an etchant. As another patterning method, for example, screen printing, optical lithography, nanoimprinting, electron beam lithography, or the like can be used. Further, as the etching liquid, for example, a ferric chloride solution, aqua regia, hydrochloric acid, oxalic acid or the like can be used.

<Wiring forming step>

Next, a film of a material for forming the wirings 10 and 11 is formed, and wirings 10 and 11 connected to the transparent conductive portion are formed.

If a film is formed using the forming materials of the wirings 10 and 11, a suitable film forming method can be used in accordance with the material for forming the wirings 10 and 11. For example, physical vacuum evaporation (PVD), chemistry such as (1) coating method such as screen printing or inkjet printing, (2) magnetron sputtering method, EB vapor deposition method for irradiating an accelerated electron beam, or the like can be used. A gas phase film formation method such as vapor deposition (CVD) or the like. Further, the film of the wiring forming material may be patterned to form a plurality of wires in one layer.

For patterning of the thin film of the material forming the wirings 10 and 11, a suitable patterning method can be used depending on the material selected for the wirings 10 and 11. For example, an etch mask corresponding to a desired pattern can be formed on the film by immersion in an etchant to form a film. pattern. As another patterning method, for example, screen printing, optical lithography, nanoimprinting, electron beam lithography, or the like can be used. Further, as the etching liquid, for example, a ferric chloride solution, aqua regia, hydrochloric acid, oxalic acid or the like can be used.

<Protective layer forming step>

Next, a film forming a material of the protective layer 14 is formed to cover the transparent conductive portion 12, the non-conductive portion 13, and the wiring 10 to form the protective layer 14.

If a film is formed using the forming material of the protective layer 14, a suitable film forming method can be used according to the material selected for the protective layer 14. For example, (1) a coating method such as screen printing or inkjet printing, (2) a lamination method such as lamination processing, or the like can be used.

Further, since the transparent conductive layer and the wiring must be formed on both surfaces of the transparent substrate 21, in each of the transparent conductive layer forming step and the wiring forming step, a transparent conductive layer and wiring are formed on both surfaces of the transparent substrate 21. In this case, the order of film formation and pattern formation in each step is appropriately determined in accordance with the film formation method and patterning method to be employed.

Further, the optical adjustment layers 22 and 23 can be formed by sequentially forming a film of the high refractive index layers 4 and 5 and a film of the low refractive index layers 6 and 7 from the transparent substrate 21 side by a well-known multilayer film forming method. Formed by a film.

Further, in the transparent conductive film 20 of Fig. 2, when a laminate in which two film substrates 15 and 16 are bonded is used as a substrate, a hard coat layer may be formed on each of the film substrates 15 and 16, After the optical adjustment layer, the transparent conductive layer, and the wiring, the film substrate is bonded via the optical adhesive layer 17 15 and 16. At this time, the protective layer 14 may be formed before the bonding of the film substrates 15 and 16, or may be formed after bonding.

(Embodiment 2)

Fig. 4 is a schematic cross-sectional view showing an example of a transparent conductive film of the second embodiment.

In the transparent conductive film 30 of the present embodiment, the optical adhesive layer 31 and the cover glass 32 are laminated on the surface of the transparent conductive film 20 of the first embodiment opposite to the surface on which the protective layer 14 is provided. As the optical adhesive layer 31, an acrylic resin, a polyoxymethylene resin, or a rubber-based resin can be used. Further, in the optical adhesive layer 31, an adhesive having a UV absorbing property or a film-like or liquid adhesive can be used. Further, the transparent substrate 21, the optical adjustment layers 22 and 23 (the high refractive index layers 4 and 5, the low refractive index layers 6 and 7), the transparent conductive layers 8 and 9 (the transparent conductive portion 12, and the transparent conductive film 30) Since the non-conductive portion 13), the wirings 10 and 11, and the protective layer 14 are the same as those described in the first embodiment (first drawing), the description thereof will not be repeated.

Fig. 5 is a schematic cross-sectional view showing a modified example of the transparent conductive film of the second embodiment.

The transparent conductive film 30 of the modification is different from the example shown in FIG. 4 in that the substrate 24 is the same as the substrate of the transparent substrate 21 as described in FIG. Since the base material 24 has been described in the modification of the first embodiment, the description thereof will be omitted.

Here, in the transparent conductive film 30 shown in FIGS. 4 and 5, the portion in which the transparent substrate 21, the optical adjustment layers 22 and 23, the transparent conductive layers 8 and 9 and the protective layer 14 are laminated is referred to as the first portion. In the laminated structure, the portion in which the optical adhesive layer 31 and the cover glass 32 are laminated is referred to as a second product. Layer structure. In the configurations of FIGS. 4 and 5, the transmitted hue b of the light penetrating the first laminated structure and the second laminated structure is 2.5 or less. In addition, the transmission hue b* refers to b* when the color of the transmitted light is expressed by the L*a*b* color system (D65 light source, 2° field of view). When the transmission hue b* of the portion where the first buildup structure and the second buildup structure overlap (that is, the portion having no wires 10 and 11) is larger than 2.5, the entire transparent conductive film has a yellow hue. If a transparent conductive film having a hue b* greater than 2.5 is used on the touch panel, the screen will have a yellow hue and the image quality will deteriorate. In addition, in order to make the transmission hue b* of the transparent conductive film 2.5 or less, for example, a laminate in which the protective layer 14 is two or more layers and a blue color may be used due to dryness. Further, the protective layer 14 may be formed of a material containing a material having a blue tint in the entire protective layer 14. In order to suppress the color tone of the transparent electrode film 20, the light transmission hue b* penetrating the first laminate structure and the second laminate structure is preferably -3.0 or more. Further, the transmission hue b* penetrating the first laminate structure is more preferably 0 or more and 2.0 or less. At this time, it is possible to further suppress the color tone of the transparent electrode film 20.

Further, in the transparent conductive film 30 of the second embodiment, the optical adjustment layers 22 and 23, the transparent conductive layers 8 and 9, and the wirings 10 and 11 can be formed on the transparent substrate 21 in accordance with the manufacturing method described in the first embodiment. After the protective layer 14, the cover glass 32 is bonded to the surface on the opposite side of the protective layer 14 via the optical adhesive layer 31.

As described above, the protective layer 14 for protecting the transparent conductive portion 12, the non-conductive portion 13, and the wiring 10 is provided on one surface of the transparent conductive film 30 of the present embodiment, and the cover glass 32 is bonded to the other surface via the optical adhesive layer 31. . However, the first buildup structure and the second buildup structure The transmission hue b* of the laminated portion (that is, the portion where the wirings 10 and 11 are not provided) is suppressed to 2.5 or less. Therefore, according to the present embodiment, it is possible to realize a transparent electrode film which is excellent in optical characteristics while protecting the transparent conductive portion 12, the non-conductive portion 13, and the wiring 10.

The transparent conductive film 30 shown in FIGS. 4 and 5 can be utilized as a constituent member of the touch panel. By using the transparent conductive film 30, the scratch resistance and high transmittance can be improved by the protective layer 14. An electrostatic capacitance type touch panel which is excellent in optical characteristics such as high transparency and which is inconspicuous in the transparent conductive portions 8 and 9.

[Examples] <Example 1>

First, a resin is applied to both surfaces of the substrate to form a lower hard coat layer and an upper hard coat layer.

For the substrate, a polyethylene terephthalate film (PET) having a thickness of 50 μm was used. Further, the film thickness of the lower hard coat layer was 1.5 μm. Further, the film thickness of the upper hard coat layer was 1.5 μm.

Next, a high refractive index layer is formed on the upper hard coat layer. The material used for the high refractive index layer is cerium oxide (Nb ₂ O ₅ ). Further, the formation of the high refractive index layer uses magnetron sputtering.

Next, a low refractive index layer is formed on the high refractive index layer. For the material of the low refractive index layer, ruthenium oxide is used. Further, the formation of the low refractive index layer uses magnetron sputtering.

Subsequently, a transparent conductive pattern electrode is formed on the low refractive index layer. The material used for the transparent conductive pattern electrode is indium oxide containing 5 wt% tin oxide. Tin (ITO). Moreover, the transparent conductive pattern electrode is controlled by magnetron A thin film of ITO is formed by sputtering, and an etching mask corresponding to the pattern is formed by screen printing, and is formed by being immersed in an etching liquid. At this time, the pattern width of the transparent conductive portion was 5 mm, and the pattern width of the non-conductive portion was 7 () μm. Further, the etching solution used a ferric chloride solution.

Next, wirings connected to the transparent conductive portion are formed. The material used for wiring is copper. Further, the wiring of the lower layer is formed by magnetron sputtering to form a thin film of copper, and an etching mask corresponding to the pattern is formed by screen printing, and immersed in an etching liquid. At this time, an aqueous sodium persulfate solution was used as the etching solution. Further, the wiring pattern of the wiring of the lower layer is a wiring pattern that is connected to the line pattern of the pattern of the transparent conductive portion.

Subsequently, a protective layer is formed to cover the transparent conductive portion, the non-conductive portion, and the wiring. The material used for the protective layer is an acrylic resin. Further, the protective layer was formed by using a microgroove roll coater, and the thickness of the protective layer was 1.0 μm.

Through the above steps, the transparent conductive film of the first embodiment was produced. The optical film thickness of each layer of the high refractive index layer/low refractive index layer/transparent conductive portion provided in the produced transparent conductive film is as follows.

High refractive index layer: 12 nm, low refractive index layer: 74 nm, transparent conductive portion: 40 nm

<Comparative Example 1>

A hard coat layer, a high refractive index layer, a low refractive index layer, a transparent conductive portion, a non-conductive portion, and a wiring member were formed as a transparent conductive film of Comparative Example 1 under the same conditions as in Example 1. . In the transparent conductive film of Comparative Example 1, a protective layer was not provided.

<Evaluation of Example 1 and Comparative Example 1>

In Example 1 and Comparative Example 1, the total light transmittance (JIS-K7105) and the transmission hue b*, the scratch test, and the pencil when expressed in the L*a*b* color system (D65 light source, field of view 2°) were performed. Hardness test (JIS-K5600).

The total light transmittance (JIS-K7105) of the conductive pattern region (JIS-K7105) of the transparent conductive film of Example 1 was 90.6%, and the transmission hue b* was 1.5, resulting in less yellow color and high transmittance. A transparent conductive film in which the pattern of the highly transparent and transparent conductive portion is inconspicuous. Further, in the transparent conductive film of Example 1, there was no scratch that could be confirmed even in the pencil hardness test (pencil hardness H, 500 g load). On the other hand, in the conductive pattern region (region without wiring) of the transparent conductive film of Comparative Example 1, the total light transmittance (JIS-K7105) was 90.0%, and the transmission hue b* was 1.8 with a yellow hue. Moreover, in the transparent conductive film of the comparative example, there were confirmed flaws in the pencil hardness test (pencil hardness H, 500 g load).

<Example 2>

Under the same conditions as in Example 1, after forming a hard coat layer, a high refractive index layer, a low refractive index layer, a transparent conductive portion, a non-conductive portion, a wiring, and a protective layer on a substrate, on the opposite side to the protective layer The cover glass having a thickness of 500 μm was bonded to the surface via an optical adhesive layer having a thickness of 100 μm, and was used as the transparent conductive film of Example 2.

<Comparative Example 2>

Under the same conditions as in Example 1, a solid hard coat layer, a high refractive index layer, a low refractive index layer, a transparent conductive portion, a non-conductive portion, and wiring were formed on a substrate, and then adhered via an optical adhesive layer having a thickness of 100 μm. Combined The cover glass having a thickness of 500 μm was used as the transparent conductive film of Comparative Example 2. In the transparent conductive film of Comparative Example 2, a protective layer was not provided.

<Evaluation of Example 2 and Comparative Example 2>

In Example 2 and Comparative Example 2, the total light transmittance (JIS-K7105) and the transmission hue b*, the scratch test, and the pencil when expressed in the L*a*b* color system (D65 light source, field of view 2°) were performed. Hardness test (JIS-K5600).

The total pattern transmittance (JIS-K7105) of the conductive pattern region (JIS-K7105) of the transparent conductive film of Example 2 was 90.6%, and the transmission hue b* was 2.5, resulting in no yellow tone and high transmittance. A transparent conductive film in which the pattern of the highly transparent and transparent conductive portion is inconspicuous. Further, in the transparent conductive film of Example 1, there was no scratch that could be confirmed even in the pencil hardness test (pencil hardness H, 500 g load). On the other hand, in the conductive pattern region (region without wiring) of the transparent conductive film of Comparative Example 1, the total light transmittance (JIS-K7105) was 90.0%, and the transmission hue b* was 3.0 with a yellow hue. Moreover, in the transparent conductive film of the comparative example, there were confirmed scratches in the pencil hardness test (pencil hardness H, 500 g load).

[Industry use possibility]

The transparent conductive film of the present invention can be utilized in a wide range of fields using a capacitive touch panel. For example, it can be utilized in a touch panel which constitutes an ATM of an financial institution, an electronic device (photocopying machine, a facsimile machine, a car navigation machine, other home appliances, etc.), a portable information terminal (a mobile phone, a smart phone). , tablet PC, etc.), electronic book terminal, portable game terminal, portable music player, vending machine and other operation panels.

1‧‧‧Substrate

2, 3‧‧‧ hard coating

4, 5‧‧‧ high refractive index layer

6, 7‧‧‧ low refractive index layer

8, 9‧‧‧ transparent conductive layer

10, 11‧‧‧ wiring

12‧‧‧Transparent Conductive Parts

13‧‧‧Non-conducting department

14‧‧‧Protective layer

20‧‧‧Transparent conductive film

21‧‧‧Transparent substrate

22, 23‧‧‧ Optical adjustment layer

Claims (10)

A transparent conductive film comprising: a transparent substrate; an optical adjustment layer provided on both surfaces of the transparent substrate; a transparent conductive layer provided on each of the optical adjustment layers; a wiring connected to the transparent conductive layer; At least one surface of the transparent conductive film covers the transparent conductive layer and the protective layer of the wiring; the protective layer has a thickness of 1 μm or more and 50 μm or less, and the substrate layer, the optical adjustment layer, the transparent conductive layer and the protective layer are formed. In the first multilayer structure, the transmission hue b* of light penetrating the first multilayer structure is 1.5 or less. A transparent conductive film further comprising: a second multilayer structure comprising: an optical adhesive layer provided on at least one surface of the transparent conductive film; and a cover glass provided on the optical adhesive layer; and penetrating the first multilayer The light transmission hue b* of the structure and the second multilayer structure is 2.5 or less. The transparent conductive film of claim 1, wherein the transparent conductive portion and the non-conductive portion are formed by patterning the transparent conductive layer provided on both surfaces of the transparent substrate. The transparent conductive film of claim 3, wherein the protective layer of the transparent conductive film is formed to cover the transparent conductive portion, the non-conductive portion, and the electrode wiring. The transparent electrode film of claim 1, wherein the optical adjustment layer is formed by laminating a metal oxide layer and a ruthenium oxide layer in this order from the transparent substrate side. The transparent conductive film of claim 1, wherein the transparent substrate is formed by sequentially laminating a film substrate, an optical adhesive layer, and an optical film. The transparent conductive film of claim 1, wherein a wiring width of the electrode wiring is 10 μm or more and 40 μm or less. A touch panel comprising the transparent conductive film of claim 1. A method for producing a transparent conductive film, which is a method for producing a transparent conductive film having an electrode-attached wiring having transparent conductive portions on both surfaces of a transparent substrate, wherein the transparent conductive portion and the non-conductive portion are formed on both surfaces of the transparent substrate, A wiring portion connected to the transparent conductive portion is formed, and a protective layer covering the transparent conductive portion is formed on at least one surface of the transparent conductive film. The method for producing a transparent conductive film according to claim 9, wherein the optical adhesive layer and the cover glass are further adhered to one surface of the transparent conductive film.