JP5780034B2 - Color tone correction film and transparent conductive film using the same - Google Patents

Description

  The present invention relates to a color correction film for a touch panel, and a transparent conductive film having a transparent conductive layer on both sides thereof.

  Currently, touch panels are widely used as devices capable of inputting information by directly touching an image display unit. A touch panel is an input device that transmits light on a display screen such as a liquid crystal display device. As a typical form, a capacitive type that utilizes the change in current capacity that occurs between a transparent electrode and a finger. There is a touch panel.

  In the capacitive touch panel, normally, two transparent conductive films are used as transparent electrodes, and a pair of transparent conductive films in which a transparent conductive layer is laminated on a transparent base film are transparent base materials. It is bonded through an adhesive layer so that the films face each other. As a transparent conductive film for a touch panel, a transparent conductive film made of metal oxide such as indium oxide containing tin oxide (tin-doped indium oxide, ITO) or zinc oxide is laminated on a transparent base film. Commonly used. Such a transparent conductive film may have a yellow coloration at the same time that the total light transmittance is reduced due to a decrease in transmittance in the short wavelength region of visible light derived from reflection and absorption of the metal oxide layer. Many. For this reason, there is a problem that it is difficult to accurately express the color of the display device arranged under the touch panel.

  In order to solve this problem, a transparent conductive film in which a transparent conductive layer is combined with a multilayer optical film has been proposed (see Patent Document 1). The transparent conductive film of Patent Document 1 has a configuration of an intermediate refractive index layer and a transparent conductive layer, either directly or sequentially from the substrate side through one or more layers such as a hard coat layer, and the optical properties of the intermediate refractive index layer. When the film thickness is 100 to 175 nm and the refractive index is 1.7 to 1.85, the effect of reducing transmitted light coloring is realized. However, when two transparent conductive films are used as transparent electrodes for a capacitive touch panel, there is a problem that the total light transmittance is reduced due to light absorption by the adhesive layer and the two base materials.

JP 2004-47456 A

  Accordingly, an object of the present invention is to provide a transparent conductive film that suppresses coloring of transmitted light and has a high total light transmittance, and a color tone correction film used as a base film thereof.

1st invention is the color correction film for electrostatic capacitance type touch panels by which the hard-coat layer is laminated | stacked on both surfaces of the transparent base film, and the color-tone correction layer is laminated | stacked on both the said hard-coat layers, The two hard coat layers have a refractive index of 1.51 to 1.61 and a film thickness of 1 to 10 μm with respect to light having a wavelength of 400 nm, and the two color tone correction layers include metal oxide fine particles and an active energy ray curable resin. And having a refractive index of 1.62 to 1.91 and a film thickness of 65 to 110 nm for light having a wavelength of 400 nm.

  2nd invention is a transparent conductive film by which the tin dope indium oxide layer was laminated | stacked on the said both color tone correction layer of the color tone correction film which concerns on 1st invention, The said both tin dope indium oxide layer has a wavelength of 400 nm. The refractive index with respect to light is 1.85 to 2.35, and the film thickness is 5 to 50 nm.

  Since the transparent conductive film of this invention is equipped with the color correction layer and the tin dope indium oxide layer on both surfaces of the transparent substrate film of 1 sheet, it comprises the transparent electrode for touchscreens with 1 transparent conductive film. be able to. Since a transparent electrode for a general touch panel is composed of two transparent conductive films in which a color tone correction layer and a tin-doped indium oxide layer (transparent conductive layer) are laminated on one surface of a transparent base film. By using the transparent conductive film of the present invention, one transparent substrate film can be reduced. Therefore, coloring of the transmitted light resulting from the transparent substrate film can be suppressed, and the total light transmittance can be improved. Moreover, the said transparent conductive film can be easily produced by using the color tone correction film of this invention.

  Furthermore, in the transparent conductive film of the present invention, the color tone correction layer has a refractive index of 1.62 to 1.91 and a film thickness of 65 to 110 nm with respect to light having a wavelength of 400 nm, and the tin-doped indium oxide layer has a wavelength of 400 nm. The refractive index with respect to light is set to 1.85 to 2.35, and the film thickness is set to 5 to 50 nm. Thus, coloring of transmitted light can be suppressed by appropriately setting the refractive index and the film thickness of the color tone correction layer and the tin-doped indium oxide layer.

  In addition, the film thickness in this invention is a physical film thickness, and is not an optical film thickness. Next, the reason for using the refractive index for light having a wavelength of 400 nm will be described. The refractive index has wavelength dispersion, and the refractive index tends to increase in the short wavelength region. Generally, in adjusting the refractive index of each layer, the value of sodium D-line (wavelength of light of 589 nm) is often used, but a layer containing metal oxide fine particles such as the color tone correction layer and tin-doped indium oxide layer of the present invention. In this case, the influence of the wavelength dispersion of the refractive index becomes large. Since it is important to control the transmittance at a wavelength of 400 nm in order to suppress yellowness, when the refractive index of each layer is adjusted with the refractive index at a wavelength of 589 nm, the transmittance at a wavelength of 400 nm cannot be sufficiently adjusted. The reduction effect cannot be obtained sufficiently. In the present application, the effect of suppressing the coloring of transmitted light is maximized by designing each layer using a refractive index having a wavelength of 400 nm.

<Color tone correction film>
The color tone correction film of this embodiment has a configuration in which a hard coat layer and a color tone correction layer are sequentially laminated on both surfaces of a transparent substrate film. That is, the color tone correction film has a configuration in which the color tone correction layer (1), the hard coat layer (1), the transparent base film, the hard coat layer (2), and the color tone correction layer (2) are laminated in order from the top. Below, the component of this color tone correction film is demonstrated in order.

<Transparent substrate film>
The transparent substrate film is made of a polyester film, and for example, a polyethylene terephthalate (PET) resin can be used. The film thickness of the transparent substrate film is usually about 25 to 400 μm, preferably about 25 to 188 μm. In addition, when a transparent base film is formed with PET resin, the refractive index of the transparent base film with respect to light with a wavelength of 400 nm is 1.72.

<Hard coat layer>
Hard coat layers are provided on both sides of the transparent substrate film in order to improve the surface hardness. In addition, when a conventional transparent conductive film is used as a transparent electrode for a touch panel, since the two transparent conductive films bonded to each other have a transparent base film, two transparent base films As a result, sufficient strength is guaranteed. On the other hand, when the transparent conductive film of the present invention is used as a transparent electrode, only one transparent conductive film is used. For this reason, there is a concern that the strength of the transparent electrode may be reduced by reducing the transparent substrate film from two to one, but the transparent conductive film of the present invention maintains a sufficient strength by having a hard coat layer. be able to.

  The material for the hard coat layer may be a conventionally known material and is not particularly limited. For example, the hardened | cured material which hardened the coating liquid for hard-coat layers formed by mixing reactive silicon compounds, such as tetraethoxysilane, and an active energy ray hardening-type resin is mentioned. Examples of the active energy ray-curable resin include monofunctional (meth) acrylate and polyfunctional (meth) acrylate. Among these, from the viewpoint of achieving both productivity and hardness, a cured product of a composition containing an active energy ray-curable resin having a pencil hardness (evaluation method: JIS-K5600-5-4) of H or higher is preferable. . Examples of the composition containing such an active energy ray-curable resin include, for example, a mixture of two or more known active energy ray-curable resins, a commercially available ultraviolet curable hard coat material, or other than these In the range where the effects of the present invention are not impaired, those further added with other components can be used. “(Meth) acrylate” refers to acrylate and methacrylate.

  The refractive index of the hard coat layer with respect to light having a wavelength of 400 nm is adjusted to be 1.51 to 1.61. When the refractive index is less than 1.51, the difference in refractive index between the transparent substrate film and the hard coat layer is increased, and interference jitter is generated, which is not preferable. When the refractive index is larger than 1.61, it is necessary to add a large amount of a high refractive index material to the hard coat layer in order to increase the refractive index. However, light absorption caused by the high refractive index material added in a large amount is required. And scattering occur, which adversely affects the color tone correction. The film thickness of the hard coat layer after drying and curing is 1 to 10 μm. When the film thickness is thinner than 1 μm, the pencil hardness is less than H, which is not preferable. When the film thickness is thicker than 10 μm, curling due to curing shrinkage becomes strong and becomes unnecessarily thick, which is not preferable because productivity and workability are lowered.

  The color tone correction film of this embodiment has two hard coat layers, that is, a hard coat layer (1) and a hard coat layer (2). The film thickness and refractive index of these two hard coat layers are as follows: They may be the same or different from each other.

<Color correction layer>
The color tone correction layer is made of a cured product obtained by curing a color tone correction layer coating liquid obtained by mixing metal oxide fine particles and an active energy ray-curable resin with active energy rays (for example, ultraviolet rays or electron beams). As the metal oxide fine particles, titanium oxide and zirconium oxide are preferable. The refractive index of titanium oxide and zirconium oxide for light with a wavelength of 400 nm varies depending on the production method, but is preferably 1.9 to 3.0. The active energy ray-curable resin used as the binder preferably has a refractive index of 1.4 to 1.7 with respect to light having a wavelength of 400 nm. Examples of the active energy ray-curable resin include monofunctional (meth) acrylate and polyfunctional (meth) acrylate.

  The color tone correction layer is formed so that the refractive index with respect to light having a wavelength of 400 nm is 1.62 to 1.91 by appropriately selecting the metal oxide fine particles and the active energy ray-curable resin. Furthermore, the film thickness of the color tone correction layer after drying and curing needs to be 65 to 110 nm. When the refractive index of the color tone correction layer is less than 1.62, the b * value of the transmitted color in the L * a * b color system defined in JIS Z 8729 becomes large, and the transparent conductive film The transmitted yellow color is clearly recognized. Moreover, when the refractive index of a color tone correction layer is larger than 1.91, the ratio of the particle | grains in a coating film will increase, and since haze will raise, a total light transmittance will fall. When the film thickness of the color tone correction layer is outside the above range, the value of b * becomes large, and the yellowish coloring of the transparent color of the transparent conductive film is clearly recognized.

  The color correction film of the present embodiment has two color correction layers, that is, a color correction layer (1) and a color correction layer (2). The film thickness and refractive index of these two color correction layers are as follows. They may be the same or different from each other.

<Formation of hard coat layer and color correction layer>
The hard coat layer is formed by applying a hard coat layer coating liquid to a transparent base film and then curing the active coat by irradiation with active energy rays. On the other hand, the color tone correction layer is formed by applying a color tone correction layer coating liquid on the formed hard coat layer and then curing it by irradiation with active energy rays. The coating method for the hard coat layer coating solution and the color tone correction layer coating solution is not particularly limited. For example, the roll coating method, spin coating method, dip coating method, spray coating method, bar coating method, knife coating method, die coating method, Any known method such as an inkjet method or a gravure coating method can be employed. The type of active energy ray is not particularly limited, but it is preferable to use ultraviolet rays from the viewpoint of convenience and the like. In addition, in order to improve adhesiveness, it is also possible to perform pre-treatments such as corona discharge treatment on the surface of the transparent substrate film in advance.

<Transparent conductive film>
The transparent conductive film has a structure in which a tin-doped indium oxide layer is laminated on the color correction layer of the color correction film. That is, the transparent conductive film includes a tin-doped indium oxide layer (1), a color tone correction layer (1), a hard coat layer (1), a transparent base film, a hard coat layer (2), and a color tone correction layer (2 ) And a tin-doped indium oxide layer (2) are sequentially laminated.

  The color of transmitted light of the transparent conductive film can be evaluated by b * of the Lab color system defined in JIS Z 8729, preferably −2 ≦ b * ≦ 2, more preferably −1 ≦ b * ≦ 1. is there. In the case of b *> 2, the transparent conductive film appears to be colored yellow, which is not preferable. On the other hand, when b * <− 2, the transparent conductive film appears to be colored blue, which is not preferable.

<Tin-doped indium oxide layer (ITO layer)>
The tin-doped indium oxide layer (ITO layer) laminated on the color correction layer is a transparent conductive layer, and has a refractive index of 1.85 to 2.35 and a film thickness of 5 to 50 nm with respect to light having a wavelength of 400 nm. . If the refractive index is out of this range, the optical interference with the color tone correction layer does not work properly, so that the transparent color of the transparent conductive film is colored and the total light transmittance is also lowered. The refractive index of the ITO layer is preferably larger than the refractive index of the color tone correction layer. When the film thickness is less than 5 nm, it is difficult to form a uniform film, and a stable resistance cannot be obtained. On the other hand, when the film thickness is thicker than 50 nm, the absorption of light by the ITO layer itself becomes strong, the effect of reducing the coloring of the transmitted color is diminished, and the total light transmittance tends to decrease, which is not preferable.

<Formation of tin-doped indium oxide layer>
The method for forming the tin-doped indium oxide layer is not particularly limited, and for example, a vapor deposition method, a sputtering method, an ion plating method, or a CVD method can be employed. Among these, the vapor deposition method and the sputtering method are particularly preferable from the viewpoint of controlling the layer thickness. In addition, after forming a tin dope indium oxide layer, it can crystallize by giving an annealing process within the range of 100 to 200 degreeC as needed. Specifically, when crystallization is performed at a high temperature, the refractive index of the tin-doped indium oxide layer tends to decrease. Accordingly, the refractive index of the tin-doped indium oxide layer can be adjusted by controlling the annealing temperature and time.

  The transparent conductive film of this embodiment has two tin-doped indium oxide layers, that is, a tin-doped indium oxide layer (1) and a tin-doped indium oxide layer (2). The film thickness and refractive index of the layers may be the same or different from each other.

  Hereinafter, the embodiment will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the scope of these examples. Further, the refractive index, transmitted color, and total light transmittance in each example were measured by the following methods.

<Refractive index (layers other than ITO layer)>
(1) On a PET film (trade name “A4100”, manufactured by Toyobo Co., Ltd.) having a refractive index of 1.72 with respect to light having a wavelength of 400 nm, a coating solution for each layer is formed by a dip coater (manufactured by Sugiyama Motochemical Co., Ltd.). The thickness of the layer was adjusted and applied so that the film thickness after drying and curing was about 100 to 500 nm.
(2) After drying, it was cured by irradiating with 400 mJ ultraviolet rays using a 120 W high-pressure mercury lamp in a nitrogen atmosphere by an ultraviolet irradiation device (manufactured by Iwasaki Electric Co., Ltd.). The back surface of the cured PET film was roughened with sandpaper, and the reflection spectrum was measured with a reflection spectral film thickness meter (“FE-3000”, manufactured by Otsuka Electronics Co., Ltd.).
(3) From the reflectance read from the reflection spectrum, the constant of the wavelength dispersion formula (Formula 1) of n-Cauchy shown below was determined, and the refractive index at a wavelength of 400 nm was determined.
N (λ) = a / λ ⁴ + b / λ ² + c (Formula 1)
(N: refractive index, λ: wavelength, a, b, c: chromatic dispersion constant)

<Refractive index (ITO layer)>
(1) Sputtering is performed on a PET film (trade name “A4100”, manufactured by Toyobo Co., Ltd.) having a refractive index of 1.72 with respect to light having a wavelength of 400 nm, using an ITO target of indium: tin = 10: 1 on the PET film. Then, a tin-doped indium oxide layer (ITO layer) as a transparent conductive layer having an actual film thickness of 20 nm was formed, and annealing was performed under the conditions of the following Examples and Comparative Examples to produce a transparent conductive film.
(2) The reflection spectrum was measured with a reflection spectral film thickness meter (“FE-3000”, manufactured by Otsuka Electronics Co., Ltd.) after roughening the back surface of the transparent conductive film with sandpaper and painting with a black paint.
(3) From the reflectance read from the reflection spectrum, the refractive index at a wavelength of 400 nm of light was obtained using the above (Formula 1).
In addition, the refractive index of each layer of Table 1 is a refractive index calculated | required from the said sample for refractive index measurement.

<Transparent color>
Using a color difference meter (“SQ-2000”, manufactured by Nippon Denshoku Industries Co., Ltd.), the transmitted color and b * of the transparent conductive film were measured. This b * is a value in the L * a * b color system defined in JIS Z 8729.

<Total light transmittance>
The total light transmittance (%) of the transparent conductive film was measured with a haze meter (“NDH2000”, manufactured by Nippon Denshoku Industries Co., Ltd.).

[Preparation of hard coat layer coating solution (HC-1)]
96 parts by mass of dipentaerythritol hexaacrylate, photopolymerization initiator [trade name: IRGACURE 184, manufactured by Ciba Specialty Chemicals Co., Ltd.] and 100 parts by mass of isobutyl alcohol were mixed to prepare a coating liquid for hard coat layer (HC -1) was prepared. The refractive index of the hard coat layer formed using the hard coat layer coating solution (HC-1) was 1.52.

[Preparation of hard coat layer coating solution (HC-2)]
96 parts by mass of dipentaerythritol hexaacrylate, 5 parts by mass of acrylic fine particles [trade name: MA-150, manufactured by Soken Chemical Co., Ltd.], photopolymerization initiator [trade name: IRGACURE 184, manufactured by Ciba Specialty Chemicals Co., Ltd.] 4 parts by mass and 100 parts by mass of isobutyl alcohol were mixed to prepare a hard coat layer coating solution (HC-2). The refractive index of the hard coat layer formed using the hard coat layer coating solution (HC-2) was 1.53.

[Preparation of coating solution for color tone correction layer]
The following raw materials were used as the color correction layer coating liquid, and the respective raw materials were mixed in the composition described in Table 1 to prepare color correction layer coating liquids M-1 to M-5. The numerical values in Table 1 are wt%. The refractive index of the color tone correction layer formed using the obtained coating liquids M-1 to M-5 for the color tone correction layer was measured. The results are shown in Table 1.

Metal oxide fine particles: Zirconium oxide fine particles having an average particle size of 0.02 μm
Titanium oxide fine particles having an average particle size of 0.02 μm Active energy ray-curable resin: Hexafunctional urethane acrylate (purple UV-7600B manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
Photopolymerization initiator: IRGACURE 184 (I-184) manufactured by Ciba Specialty Chemicals
Solvent: methyl isobutyl ketone

(Example 1-1)
A coating liquid for hard coat layer (HC-1) is applied to one surface of a PET film having a thickness of 125 μm with a bar coater, and cured by irradiating with 400 mJ ultraviolet rays with a 120 W high-pressure mercury lamp. A hard coat layer (1) having a thickness of 2.5 μm was formed. Subsequently, a hard coat layer coating solution (HC-2) is applied to the other surface of the PET film with a bar coater, and cured by irradiating with 400 mJ of ultraviolet light with a 120 W high-pressure mercury lamp, whereby the film after dry curing is obtained. A hard coat layer (2) having a thickness of 2.5 μm was formed.
On the hard coat layer (1), the coating liquid for color tone correction layer (M-1) is applied with a bar coater and cured by irradiating with 400 mJ of ultraviolet light with a 120 W high-pressure mercury lamp. A color tone correction layer (1) having a thickness of 95 nm was formed. Subsequently, the coating liquid for color tone correction layer (M-1) is applied on the hard coat layer (2) with a bar coater, and cured by irradiating with 400 mJ ultraviolet rays with a 120 W high pressure mercury lamp, thereby drying and curing. A color tone correction layer (2) having a film thickness of 95 nm later was formed to produce a color tone correction film (S-1).

(Example 1-2)
A color correction film (S-2) was produced in the same manner as in Example 1-1 except that the film thickness after drying and curing of the color correction layer (2) was 65 nm.

(Example 1-3)
A color correction film (S-3) was produced in the same manner as in Example 1-1 except that the film thickness after drying and curing of the color correction layer (2) was changed to 110 nm.

(Example 1-4)
The color correction film (S-4) is the same as Example 1-1 except that the color correction layer coating liquid of the color correction layer (2) is M-2 and the film thickness after drying and curing is 90 nm. Was made.

(Example 1-5)
The color correction film (S-5) is the same as Example 1-1 except that the color correction layer coating liquid of the color correction layer (2) is M-3 and the film thickness after drying and curing is 100 nm. Was made.

(Example 1-6)
The color correction layer coating liquid of the color correction layer (1) is M-2, the film thickness after drying and curing is 90 nm, and the color correction layer coating liquid of the color correction layer (2) is M-3. A color correction film (S-6) was produced in the same manner as in Example 1-1 except that the film thickness after drying and curing was 100 nm.

(Example 1-7)
Example 1 except that the hard coat layer coating solution for the hard coat layer (1) and the hard coat layer (2) was HC-3 [trade name: Lucifar NAB-2000, manufactured by Nippon Paint Co., Ltd.] In the same manner as in No. 1, a color tone correction film (S-7) was produced. The refractive index of the hard coat layer formed using the hard coat layer coating solution (HC-3) was 1.54.

Table 2 shows the properties of the color tone correction films obtained in Examples 1-1 to 1-7.

(Example 2-1)
By sputtering using an ITO target of indium: tin = 10: 1 on the color correction layer (1) of the color correction film (S-1), a tin-doped indium oxide layer (ITO layer having a thickness of 20 nm) ) (1) is formed, and then a tin-doped indium oxide layer (2) having a film thickness of 20 nm is formed on the color correction layer (2) by sputtering using an ITO target of indium: tin = 10: 1. ) And an annealing treatment at 150 ° C. for 30 minutes to produce a transparent conductive film. About the obtained transparent conductive film, the transmission color b * and the total light transmittance were measured by the said method. The results are shown in Table 3 below.

(Example 2-2)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was changed to (S-2).

(Example 2-3)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was changed to (S-3).

(Example 2-4)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was changed to (S-4).

(Example 2-5)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was changed to (S-5).

(Example 2-6)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was changed to (S-6).

(Example 2-7)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was changed to (S-7).

(Example 2-8)
A color correction film in the same manner as in Example 2-1, except that the thickness of the tin-doped indium oxide layer (1) and the tin-doped indium oxide layer (2) was 30 nm and the annealing treatment was 150 ° C. for 60 minutes. And the transparent conductive film was produced.

(Example 2-9)
A color tone correction film and a transparent conductive film were produced in the same manner as in Example 2-1, except that the annealing treatment was performed at 100 ° C. for 60 minutes.

(Comparative Example 1-1)
The coating film for hard coat layer (HC-1) is coated on a 125 μm-thick PET film with a bar coater, and cured by irradiating with a 120 W high-pressure mercury lamp by irradiating with 400 mJ of ultraviolet rays to obtain a film thickness after drying and curing. A hard coat layer having a thickness of 2.5 μm was formed. Next, a coating solution for color tone correction layer (M-1) is applied onto the hard coat layer with a bar coater, and cured by irradiating with 400 mJ of ultraviolet light with a 120 W high-pressure mercury lamp, whereby the film after drying and curing is applied. A color tone correction layer having a thickness of 95 nm was formed to produce a color tone correction film. Next, on the color correction layer of the color correction film, sputtering is performed using an ITO target of indium: tin = 10: 1 to form a tin-doped indium oxide layer as a transparent conductive layer, and annealed at 150 ° C. for 30 minutes. The transparent electroconductive film was produced by processing. The two transparent conductive films obtained were bonded so that the PET films face each other through a transparent adhesive transfer tape [trade name: 8146-2, manufactured by Sumitomo 3M Limited], and Comparative Example 1 -1 transparent conductive film was produced. About the obtained transparent conductive film, the transmission color b * and the total light transmittance were measured by the said method. The results are shown in Table 4.

(Comparative Example 2-1)
A color correction film (S-8) was produced in the same manner as in Example 1-1 except that the film thickness after drying and curing of the color correction layer (2) was 120 nm.

(Comparative Example 2-2)
A color correction film (S-9) was produced in the same manner as in Example 1-1 except that the film thickness after drying and curing of the color correction layer (2) was 55 nm.

(Comparative Example 2-3)
A color correction film (S-10) was produced in the same manner as in Example 1-1 except that the color correction layer coating liquid for the color correction layer (2) was M-4.

(Comparative Example 2-4)
A color correction film (S-11) was produced in the same manner as in Example 1-1 except that the color correction layer coating liquid for the color correction layer (2) was M-5.

Table 5 shows the properties of the color tone correction films obtained in Comparative Examples 2-1 to 2-4.

(Comparative Example 3-1)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color correction film was changed to (S-8).

(Comparative Example 3-2)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was (S-9).

(Comparative Example 3-3)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was changed to (S-10).

(Comparative Example 3-4)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the color tone correction film was changed to (S-11).

(Comparative Example 3-5)
A transparent conductive film was produced in the same manner as in Example 2-1, except that the thickness of the ITO layer (2) was 70 nm.

The transmittance b * and the total light transmittance of the transparent conductive films obtained in Comparative Examples 3-1 to 3-4 were measured by the above methods. The results are shown in Table 6.

In Examples 2-1 to 2-9, since the refractive index and the film thickness of the hard coat layer, the color tone correction layer, and the tin-doped indium oxide layer are set within the range defined by the present invention, the transmitted color b * The color of the transparent conductive film was sufficiently suppressed, and an excellent total light transmittance could be realized.
On the other hand, in Comparative Example 1-1, since an extra adhesive layer and a transparent substrate film were used, the total light transmittance was poor. In Comparative Examples 3-1 to 3-5, any one of the color tone correction layer, the refractive index of the tin-doped indium oxide layer, and the film thickness is set outside the range defined by the present invention. As a result, the transparent conductive film was colored.

Claims (2)

A hard coat layer is laminated on both sides of the transparent substrate film, and a color tone correction film for a capacitive touch panel in which a color tone correction layer is laminated on both the hard coat layers,
Both the hard coat layers have a refractive index of 1.51 to 1.61 with respect to light having a wavelength of 400 nm and a film thickness of 1 to 10 μm.
The color tone correction layer is a color tone correction film comprising metal oxide fine particles and an active energy ray-curable resin, having a refractive index of 1.62 to 1.91 and a film thickness of 65 to 110 nm with respect to light having a wavelength of 400 nm. A transparent conductive film in which a tin-doped indium oxide layer is laminated on the both color correction layers of the color correction film according to claim 1,
The both tin-doped indium oxide layers are transparent conductive films having a refractive index of 1.85 to 2.35 and a film thickness of 5 to 50 nm with respect to light having a wavelength of 400 nm.