JP6085974B2 - Transparent conductive film - Google Patents

Description

  The present invention relates to a color correction film for a touch panel and a transparent conductive film provided with a transparent conductive layer composed of a tin-doped indium oxide layer on the color correction film.

  Currently, touch panels are widely used as devices that can input 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.

  As a transparent conductive film for a touch panel, a transparent conductive film made of a metal oxide such as indium oxide containing tin oxide (tin-doped indium oxide, ITO) or zinc oxide is laminated on a transparent base film. Is generally used. Such a transparent conductive film may show a decrease in the total light transmittance or a yellow coloration due to a decrease in the transmittance in the visible light short wavelength region derived from the reflection and absorption of light in the transparent conductive 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 addition, it is required that the display has excellent optical uniformity and can display delicate images.

  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). In Patent Document 1, a hard coat layer, a high refractive index layer (first color tone correction layer), a low refractive index layer (second color tone correction layer), and tin-doped oxidation are sequentially performed from the surface of the transparent base film made of a polyester film. An indium layer is stacked. In this transparent conductive film, the thickness and refractive index of each layer are specified in such a laminated structure, and the hue adjustment function and the reflection reduction function are appropriately exhibited, thereby increasing the total light transmittance and reducing the coloring. It is illustrated. Specifically, the high refractive index layer is formed from metal oxide fine particles and an ultraviolet curable binder, has a refractive index of 1.63-1.86, a film thickness of 40-90 nm, A transparent conductive film having a refractive index of 1.33 to 1.53 and a film thickness of 10 to 50 nm, and a tin-doped indium oxide layer having a refractive index of 1.85 to 2.35 and a film thickness of 5 to 50 nm. Has been proposed.

  Patent Document 2 describes that it is preferable to use a transparent substrate film as a cellulose ester film or a cycloolefin polymer film because it has no optical anisotropy.

JP 2011-98563 A JP 2004-347928 A

  However, in the transparent conductive film described in Patent Document 1, a polarizing polyester film is used as a transparent base film, and the thickness and refractive index of each layer according to this are specified. When polarized sunglasses are used, there is a problem that rainbow unevenness due to stretching of the polyester film is visible.

  In addition, the optical film described in Patent Document 2 has a hard coat layer, which causes a problem that the optical film is easily torn.

  Therefore, the object of the present invention is to suppress the coloring of transmitted light, and even when the touch panel user uses polarized sunglasses, the rainbow unevenness is not visible and is not easily torn, that is, the transparent conductive material having high tear resistance. Another object of the present invention is to provide a color correction film used as a base film and a base film thereof.

In the first invention, a first color tone correction layer , a second color tone correction layer, and a tin-doped indium oxide layer are directly laminated in this order on one surface of the optically isotropic base film, and the first color tone correction layer Contains metal oxide fine particles, has a refractive index of 1.59 to 1.82, and a film thickness of 25 to 90 nm, and the second color tone correction layer contains silica fine particles and has a refractive index of 1.32 to 1. .52, thickness 10~55nm der is, the tin-doped indium oxide layer has a refractive index of 1.85 to 2.35, the film thickness is 5 to 50 nm, and is defined in JIS K7128-1 A transparent conductive film having a tearing force of 0.3 (N) or more . In addition, the film thickness in this invention is a physical film thickness and is not an optical film thickness.

  In the present invention, “OO to XX” indicating a numerical range means that the numerical values of the lower limit (OO) and the upper limit (XX) are included. Therefore, if it is expressed accurately, it will be “XX or more and XX or less”.

According to the present invention, the optically isotropic substrate film is used as a transparent substrate film, and the refractive index and film thickness of each layer (first color tone correction layer, second color tone correction layer and tin-doped indium oxide layer) are appropriately set. As a result, coloring of transmitted light can be suppressed, and even when the touch panel user uses polarized sunglasses, rainbow unevenness is not visible and a transparent conductive film having high tear resistance can be provided .

《Color tone correction film》
The color tone correction film of the present embodiment uses an optically isotropic base film as a transparent base film, and the first color tone correction layer and the second color tone correction layer directly on one surface thereof, that is, without laminating a hard coat layer. Are laminated in this order from the transparent substrate film side. Below, the component of this color tone correction film is demonstrated in order.

<Light isotropic substrate film>
As the optically isotropic base film, a film made of a polycarbonate resin, a triacetyl cellulose resin, a norbornene resin, or a cycloolefin resin can be used. As a film made of polycarbonate resin, a polycarbonate film ("Pure Ace" C110-100, refractive index: 1.59) manufactured by Teijin Chemicals Limited, and as a film made of triacetyl cellulose resin, a triacetyl cellulose film manufactured by Fuji Film Co., Ltd. ( Fujitac, refractive index: 1.49), a film made of norbornene resin, Arton film made by JSR Corporation, and a film made of cycloolefin resin, Zeonor film made by Nippon Zeon Co., Ltd. (ZF14, ZF16, refractive index: 1. 53). The film thickness of the optically isotropic substrate film is usually about 25 to 400 μm, preferably about 25 to 200 μm.

<First color tone correction layer>
The first color tone correction layer is a high refractive index layer having a refractive index larger than that of the optical isotropic substrate film and the second refractive index layer, and cooperates with each other depending on the relative refractive index relationship with the second color tone correction layer. It is a layer for adjusting the color tone of the color tone correction film or transparent conductive film (suppressing the coloring of the transmitted color). The first color tone correction layer is formed from a cured product obtained by curing a coating solution for the first color tone correction layer 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). Become.

  The metal oxide fine particles are blended for positively increasing the refractive index. As such metal oxide fine particles, titanium oxide and zirconium oxide are preferable. The refractive indexes of titanium oxide and zirconium oxide are preferably 1.9 to 3.0, although they vary depending on the production method.

30 to 90 parts by weight of the metal oxide fine particles are contained in the first color tone correction layer with respect to 100 parts by weight in total of the metal oxide fine particles and the active energy ray-curable resin. If the content of the metal oxide fine particles is less than 30 parts by weight, the refractive index of the first color tone correction layer is outside the range described later, which is not preferable. On the other hand, when the content of the metal oxide fine particles exceeds 90 parts by weight, the relative amount of the metal oxide fine particles with respect to the coating film increases and the coating film becomes brittle. The primary number average particle diameter of the metal oxide fine particles is preferably 500 nm or less, and more preferably 1 to 100 nm.

  The active energy ray-curable resin used as the binder preferably has a refractive index of 1.4 to 1.7. Examples of the active energy ray-curable resin include monofunctional (meth) acrylate and polyfunctional (meth) acrylate. Specifically as monofunctional (meth) acrylate, (meth) acrylic acid alkyl ester, (meth) acrylic acid (poly) ethylene glycol group-containing (meth) acrylic acid ester and the like are preferable. Examples of the polyfunctional (meth) acrylate include ester compounds of polyhydric alcohol and (meth) acrylic acid, polyfunctional polymerizable compounds containing two or more (meth) acryloyl groups such as urethane-modified acrylate, and the like. In the present specification, “(meth) acrylate” refers to acrylate and methacrylate. Similarly, “(meth) acrylic monomer” described later refers to an acrylic monomer and a methacrylic monomer, and “(meth) acryloyl group” refers to an acryloyl group and a methacryloyl group. The active energy ray-curable resin is contained in the first color tone correction layer in an amount of 10 to 70 parts by weight with respect to a total of 100 parts by weight of the metal oxide fine particles and the active energy ray-curable resin. If the content of the active energy ray-curable resin is less than 10 parts by weight, the relative amount of the active energy ray-curable resin with respect to the coating film is small and the coating film becomes brittle. On the other hand, when the content of the active energy ray-curable resin exceeds 70 parts by weight, the refractive index of the first color tone correction layer is outside the range described later, which is not preferable.

  Furthermore, the first color tone correction layer also contains a photopolymerization initiator. The photopolymerization initiator is used as a polymerization initiator when a coating film is formed by curing the hard coat layer coating liquid with an active energy ray such as ultraviolet (UV). The photopolymerization initiator is not particularly limited as long as it initiates polymerization upon irradiation with active energy rays, and known compounds can be used. For example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -One, acetophenone polymerization initiators such as 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, benzoin, 2,2-dimethoxy 1,2 -Benzoin polymerization initiators such as diphenylethane-1-one, benzophenone, [4- (methylphenylthio) phenyl] phenylmethanone, 4-hydroxybenzophenone, 4-phenylbenzophenone, 3,3 ', 4,4' -Benzophenone polymerization initiators such as tetra (t-butylperoxycarbonyl) benzophenone, 2-chlorothio Xanthone, such thioxanthone type polymerization initiators such as 2,4-diethyl thioxanthone, and the like. 0.1-10 weight part of a photoinitiator is contained in a 1st color tone correction layer with respect to a total of 100 weight part of metal oxide microparticles | fine-particles and active energy ray hardening-type resin. When the content of the photopolymerization initiator is less than 0.1 part by weight, the active energy ray-curable resin is not sufficiently cured. On the other hand, if the content of the photopolymerization initiator exceeds 10 parts by weight, the photopolymerization initiator is unnecessarily increased, which is not preferable.

  The coating solution for the first color tone correction layer is prepared by appropriately diluting a resin composition containing metal oxide fine particles, an active energy ray-curable resin, and a photopolymerization initiator with a solvent. The solvent is not particularly limited as long as it is a known one that has been conventionally used for coating liquids for forming each layer in this type of color tone correction film, for example, an alcohol-based, ketone-based, or ester-based solvent is appropriately selected. it can.

  The first color tone correction layer is formed so as to have a refractive index of 1.59 to 1.82 by including the metal oxide fine particles, the active energy ray-curable resin, and the photopolymerization initiator in the above ranges, respectively. . Furthermore, the film thickness of the first color tone correction layer after drying and curing needs to be 25 to 90 nm. When the refractive index of the first color tone correction layer is less than 1.59, the b * value of the transmitted color in the L * a * b * color system defined in JIS Z 8729 is increased, and the transparent conductive The yellow color of the transmitted color of the conductive film is clearly recognized. Further, when the refractive index of the first color tone correction layer is larger than 1.82, the ratio of particles in the coating film increases, and the haze value increases, so that the total light transmittance decreases. When the film thickness of the first color tone correction layer is out of the above range, the value of b * increases, and the yellowish coloring of the transparent color of the transparent conductive film is clearly recognized.

<Second color tone correction layer>
The second color tone correction layer is a low refractive index layer having a lower refractive index than that of the first color tone correction layer, and cooperates with each other depending on the relative refractive index relative to the first color tone correction layer. It is a layer for adjusting the color tone of the conductive film (suppressing the coloring of the transmitted color). The second color tone correction layer is made of a cured product obtained by curing a coating solution for a second color tone correction layer obtained by mixing silica fine particles and an active energy ray-curable resin with active energy rays (for example, ultraviolet rays or electron beams).

  Silica fine particles are blended in order to actively lower the refractive index. As the silica fine particles, colloidal silica and hollow silica fine particles are preferable. The refractive indexes of colloidal silica and hollow silica fine particles vary depending on the production method, but are preferably 1.25 to 1.50. It is preferable that 0-90 weight part of silica fine particles are contained in a 2nd color tone correction layer with respect to a total of 100 weight part of silica fine particle and active energy ray hardening-type resin. When the content of silica fine particles is more than 90 parts by weight, the coating film strength becomes weak, which is not preferable. Moreover, the primary number average particle diameter of the silica fine particles is preferably 500 nm or less, and more preferably 1 to 100 nm.

  The active energy ray curable resin used as the binder may be the same type as the active energy ray curable resin used in the first color tone correction layer. In addition, a compound in which some of the hydrogen atoms of the active energy ray-curable resin used in the first color tone correction layer are substituted with fluorine may be used. Any known material that has been conventionally used can be used without any particular limitation. For example, monofunctional (meth) acrylate, polyfunctional (meth) acrylate fully or partially fluorinated alkyl, alkenyl, aryl esters, fully or partially fluorinated vinyl ethers, fully or partially fluorinated vinyl esters, fully or partially fluorine Vinyl chlorides and the like. In addition, two or more different types of active energy ray curable resins may be mixed and used. The active energy ray curable resin is contained in the second color tone correction layer in an amount of 10 to 100 parts by weight with respect to 100 parts by weight in total of the silica fine particles and the active energy ray curable resin. If the content of the active energy ray-curable resin is less than 10 parts by weight, the relative amount of the active energy ray-curable resin with respect to the coating film is small and the coating film becomes brittle.

  Furthermore, the second color tone correction layer also contains a photopolymerization initiator. The same photopolymerization initiator as the photopolymerization initiator used in the first color tone correction layer may be used. The photopolymerization initiator is contained in the second color tone correction layer in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight in total of the silica fine particles and the active energy ray-curable resin. When the content of the photopolymerization initiator is less than 0.1 part by weight, the active energy ray-curable resin is not sufficiently cured. On the other hand, if the content of the photopolymerization initiator exceeds 10 parts by weight, the photopolymerization initiator is unnecessarily increased, which is not preferable. The solvent for the second color tone correction layer coating solution may be the same as the solvent used in the first color tone correction layer.

  The second color tone correction layer is formed so as to have a refractive index of 1.32 to 1.52 by including silica fine particles and an active energy ray-curable resin in the above ranges. Furthermore, the film thickness of the second color tone correction layer after drying and curing needs to be 10 to 55 nm. When the refractive index of the second color tone correction layer is less than 1.32, the ratio of particles in the coating film increases and the haze value increases, so the total light transmittance decreases. When the refractive index of the second color correction layer is greater than 1.52, the b * value of the transmitted color in the L * a * b * color system defined in JIS Z 8729 becomes large. The transparent yellow color of the transparent conductive film is clearly recognized. When the film thickness of the second 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.

<Formation of first color tone correction layer and second color tone correction layer>
The first color tone correction layer is formed by applying a coating solution for the first color tone correction layer directly on one surface of the optically isotropic base film and then curing it by irradiation with active energy rays. The second color tone correction layer is formed by applying the second color tone correction layer coating liquid on the formed first color tone correction layer and then curing it by irradiation with active energy rays.

  The coating method for the first color tone correction layer coating solution and the second color tone correction layer coating solution is not particularly limited. For example, roll coating method, spin coating method, dip coating method, spray coating method, bar coating method, knife coating method. Any known method such as a die coating method, an ink jet method, or a gravure coating method may 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 the adhesiveness of the first color tone correction layer to the light isotropic base film, it is possible to pre-treat the surface of the light isotropic base film such as a corona discharge treatment in advance.

《Transparent conductive film》
The transparent conductive film has a configuration in which a tin-doped indium oxide layer is laminated on the second color tone correction layer of the color tone correction film. That is, the transparent conductive film has a configuration in which a tin-doped indium oxide layer, a second color tone correction layer, a first color tone correction layer, and a light isotropic base film are sequentially laminated from the top (front side).

  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. When 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.

  The total light transmittance of the transparent conductive film is preferably 90% or more. When the total light transmittance is less than 90%, the luminance deteriorates when used for a member such as a touch panel, which is not preferable. Further, the haze value is preferably less than 1%. When the haze value is 1% or more, the transparency is lowered, and the visibility of the display image is deteriorated when used for a member such as a touch panel.

<Tin-doped indium oxide layer>
A tin-doped indium oxide layer (hereinafter sometimes abbreviated as an ITO layer) laminated on the second color tone correction layer is a transparent conductive layer having a refractive index of 1.85 to 2.35 and a film thickness of 5-50 nm. If the refractive index is outside this range, the optical interference with the first color correction layer and the second color correction layer will not work properly, so the transparent conductive film will be colored and the total light transmittance will be reduced. To do. 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.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the scope of these examples.

[Preparation of coating liquid for first color tone correction layer]
Using the following raw materials as the coating solution for the first color tone correction layer, each raw material having the composition described in Table 1 below, metal oxide fine particles and active energy ray-curable resin, photopolymerization initiator, and solvent, The mixture was mixed at a weight ratio of 100: 5: 1000 to prepare first color tone correction layer coating liquids C1-1 to C1-5.

  As raw materials, zirconium oxide fine particle dispersion (CIRM Kasei Co., Ltd. ZRMEK 25% -F47) having a primary number average particle size of 30 nm or titanium oxide fine particles having a primary number average particle size of 30 nm is used as metal oxide fine particles. A dispersion (RTTMIBK15WT% -N24 manufactured by CI Kasei Co., Ltd.) was used. A hexafunctional urethane acrylate (purple light UV-7600B manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was used as the active energy ray-curable resin. IRGACURE184 manufactured by Ciba Specialty Chemicals Co., Ltd. was used as a photopolymerization initiator. Moreover, methyl isobutyl ketone was used as a solvent.

The refractive index of the color tone correction layer formed using the obtained first color tone correction layer coating liquids C1-1 to C1-5 was measured by the following method. The results are also shown in Table 1.
<Refractive index (layers other than ITO layer)>
(1) The coating liquid for each layer is dried and cured on a PET film having a refractive index of 1.67 (trade name “A4100”, manufactured by Toyobo Co., Ltd.) using a dip coater (produced by Motori Sugiyama). The thickness of the layer was adjusted so as to be about 100 to 1000 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 obtained, and the refractive index at the wavelength of 589 nm was obtained.
N (λ) = a / λ ⁴ + b / λ ² + c (Formula 1)
(N: refractive index, λ: wavelength, a, b, c: chromatic dispersion constant)

[Preparation of coating solution for second color tone correction layer]
The following raw materials are used as the coating solution for the second color tone correction layer, and each raw material has the composition described in Table 2 below, and a fine particle component (silica fine particles or metal oxide fine particles) and an active energy ray-curable resin, and photopolymerization. The initiator and the solvent were mixed at a weight ratio of 100: 5: 4000 to prepare second color tone correction layer coating liquids C2-1 to C2-11. Moreover, the refractive index of the color tone correction layer formed using the obtained coating liquids C2-1 to C2-11 for the second color tone correction layer was measured by the above method. The results are also shown in Table 2.

  The raw materials are silica fine particles, acrylic modified hollow silica fine particles through rear NAU manufactured by JGC Catalysts & Chemicals Co., Ltd. having a primary number average particle size of 60 nm, or PL manufactured by Fuso Chemical Industries Co., Ltd. having a primary number average particle size of 60 nm. -1 was used. Further, as the metal oxide fine particles, a zirconium oxide fine particle dispersion having a primary number average particle diameter of 30 nm (ZRMEK 25% -F47 manufactured by CI Kasei Co., Ltd.) was used. Moreover, as an active energy ray curable resin, Daikin Industries, Ltd. OPTOOL AR110 which is a mixture of Nippon Kayaku Co., Ltd. DPHA or a functional group-containing fluorine-containing monomer, a crosslinking group-containing fluorine-containing monomer, and an adhesive group-containing monomer. Or 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-1,10-decanyl diacrylate, the same monoester and Kyoeisha Chemical Co., Ltd. 16FDA, which is a mixture of unterminated acrylic acid, or JSR Co., Ltd. OPSTA TU2205, which is a low refractive index material, was used. IRGACURE907 manufactured by Ciba Specialty Chemicals Co., Ltd. was used as a photopolymerization initiator. And isopropyl alcohol was used as a solvent.

[Preparation of hard coat layer coating solution (HC1-1)]
For hard coat layer by mixing 100 parts by weight of dipentaerythritol hexaacrylate (DPHA), 5 parts by weight of photopolymerization initiator [trade name: IRGACURE 184, manufactured by Ciba Specialty Chemicals Co., Ltd.], and 150 parts by weight of isobutyl alcohol. A coating solution (HC1-1) was prepared. The refractive index of the hard coat layer formed using the hard coat layer coating solution (HC1-1) was 1.51.

(Example 1-1)
The first color tone correction layer coating liquid (C1-1) is applied to one surface of a ZEONOR film (product name: ZF14, film thickness: 100 μm) manufactured by Nippon Zeon Co., Ltd. as a photoisotropy base film using a bar coater. The first color tone correction layer was formed by irradiating and curing 400 mJ ultraviolet rays with a 120 W high pressure mercury lamp. A second color tone correction layer coating liquid (C2-1) is applied on the first color tone correction layer with a bar coater, and cured by irradiating with 400 mJ ultraviolet rays with a 120 W high pressure mercury lamp. And a color tone correction film (S1-1) was prepared (see Table 3 below for the thickness of each layer).

(Example 1-2 to Example 1-15)
A color tone correction film (S1-2 to S1-15) was prepared in the same manner as in Example 1-1 except that the first color tone correction layer and the second color tone correction layer were made of the materials and film thicknesses shown in Table 3 below. Produced.

(Example 1-16)
A color correction film (S1-16) in the same manner as in Example 1-1 except that a polycarbonate film (“Pure Ace” C110-100, film thickness: 100 μm) manufactured by Teijin Chemicals Limited was used as the optically isotropic base film. ) Was produced.

(Comparative Example 1-1 to Comparative Example 1-7)
A color tone correction film (S′1-1 to S′1) was obtained in the same manner as in Example 1-1 except that the first color tone correction layer and the second color tone correction layer were made of the materials and film thicknesses shown in Table 4 below. -7) was produced.

(Comparative Example 1-8)
A color tone correction film (S′1-8) was produced in the same manner as in Example 1-1 except that the optically isotropic base film was changed to a PET film having a thickness of 125 μm.

(Comparative Example 1-9)
A coating liquid for hard coat layer (HC1-1) is applied to one side of a ZEONOR film (product name: ZF14, film thickness: 100 μm) manufactured by Nippon Zeon Co., Ltd. as a light isotropic base film with a bar coater. A hard coat layer was formed by curing by irradiating 400 mJ ultraviolet rays with a high-pressure mercury lamp. On the hard coat layer, the first color tone correction layer coating solution (C1-1) is applied with a bar coater, and cured by irradiating with 400 mJ ultraviolet rays with a 120 W high pressure mercury lamp to form a first color tone correction layer. did. A second color tone correction layer coating liquid (C2-1) is applied on the first color tone correction layer with a bar coater, and cured by irradiating with 400 mJ ultraviolet rays with a 120 W high pressure mercury lamp. A color tone correction film (S′1-9) was produced.

(Example 2-1)
A tin-doped indium oxide layer (ITO layer) having a film thickness of 20 nm is formed on the second color correction layer of the color tone correction film (S1-1) by sputtering using an ITO target of indium: tin = 10: 1. And annealed at 150 ° C. for 30 minutes to produce a transparent conductive film.

(Example 2-2 to Example 2-16)
Using each color tone correction film (S1-2 to S1-16) described in Table 3, a transparent conductive film was produced in the same manner as in Example 2-1.

(Example 2-17)
A tin-doped indium oxide layer (ITO layer) having a film thickness of 20 nm is formed on the second color correction layer of the color tone correction film (S1-1) by sputtering using an ITO target of indium: tin = 10: 1. Was formed, and annealed at 150 ° C. for 2 hours to produce a transparent conductive film.

(Example 2-18)
A tin-doped indium oxide layer (ITO layer) having a film thickness of 20 nm is formed on the second color correction layer of the color tone correction film (S1-1) by sputtering using an ITO target of indium: tin = 10: 1. And an annealing treatment at 100 ° C. for 1 hour was performed to produce a transparent conductive film.

(Example 2-19)
A tin-doped indium oxide layer (ITO layer) having a film thickness of 50 nm is formed by performing sputtering on the second color correction layer of the color tone correction film (S1-1) using an ITO target of indium: tin = 10: 1. And annealed at 150 ° C. for 30 minutes to produce a transparent conductive film.

  About the obtained transparent conductive film of each Example, the refractive index of the ITO layer, the transmitted color b *, the total light transmittance, the haze value, the rainbow unevenness, and the tearing force were evaluated by the following methods. The results are shown in Table 5 below.

<Refractive index (ITO layer)>
(1) Sputtering is performed on a PET film having a refractive index of 1.67 (trade name “A4100”, manufactured by Toyobo Co., Ltd.) using an ITO target of indium: tin = 10: 1, and a transparent film having an actual film thickness of 20 nm. A tin-doped indium oxide layer (ITO layer) as a conductive layer was formed, and annealed 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 589 nm of light was obtained using the above (Equation 1).

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

<Rainbow rainbow>
The transparent conductive film was observed with polarized sunglasses and evaluated in the following two stages.
○: Rainbow irregularities are not visible ×: Rainbow irregularities are visible

<Tearing force>
The tearing force (N) of the transparent conductive film was measured by using a tensile / compression tester (“STA-1150”, manufactured by A & D Co., Ltd.). This tear force is a value in the tear force defined in JIS K 7128-1.
○: Tear force is 0.3 (N) or more ×: Tear force is less than 0.3 (N)

(Comparative Example 2-1 to Comparative Example 2-9)
A transparent conductive film was produced in the same manner as in Example 2-1, using each color tone correction film (S′1-1 to S′1-9) described in Table 4.

(Comparative Example 2-10)
A tin-doped indium oxide layer (ITO layer) having a film thickness of 20 nm is formed on the second color correction layer of the color tone correction film (S1-1) by sputtering using an ITO target of indium: tin = 10: 1. Was formed, and annealed at 150 ° C. for 2 hours to produce a transparent conductive film.

(Comparative Example 2-11)
A tin-doped indium oxide layer (ITO layer) having a film thickness of 20 nm is formed on the second color correction layer of the color tone correction film (S1-1) by sputtering using an ITO target of indium: tin = 10: 1. And an annealing treatment at 100 ° C. for 1 hour was performed to produce a transparent conductive film.

(Comparative Example 2-12)
A tin-doped indium oxide layer (ITO layer) having a film thickness of 50 nm is formed by performing sputtering on the second color correction layer of the color tone correction film (S1-1) using an ITO target of indium: tin = 10: 1. And annealed at 150 ° C. for 30 minutes to produce a transparent conductive film.

  About the transparent conductive film of each comparative example obtained, the refractive index, the transmission color b *, the total light transmittance, the haze value, the rainbow unevenness, and the tearing force of the ITO layer were obtained in the same manner as in the above examples. And evaluated. The results are shown in Table 6 below.

  As is clear from the results in Table 5, in Examples 2-1 to 2-19, a light isotropic substrate film is used as the transparent substrate film, and accordingly, the first color tone correction layer, the second color tone correction layer, and Since the refractive index and film thickness of the tin-doped indium oxide layer are in an appropriate range, rainbow unevenness does not occur even when observed with polarized sunglasses, the tearing force is large, and the transparent color b * is small. It was possible to sufficiently suppress the coloring.

  On the other hand, as is clear from the results in Table 6, Comparative Examples 2-1 to 2-7 and 2-10 to 2-12 are the first color tone correction layer, the second color tone correction layer, and the tin-doped indium oxide layer. Since either the refractive index or the film thickness is in an inappropriate range, the transparent color b * is large and the transparent conductive film is colored. Moreover, since Comparative Example 2-8 used a PET film as the transparent substrate film, the result was that rainbow unevenness was seen when observed with polarized sunglasses. Moreover, since Comparative Example 2-9 was provided with the hard-coat layer, the value of tearing force was set to 0.1 (N), and it was set as x determination.

Claims (1)

A first color tone correction layer , a second color tone correction layer, and a tin-doped indium oxide layer are laminated in this order directly on one surface of the light isotropic substrate film,
The first color tone correction layer includes metal oxide fine particles, and has a refractive index of 1.59 to 1.82 and a film thickness of 25 to 90 nm.
The second color tone correcting layer may include silica fine particles, the refractive index is 1.32 to 1.52, Ri thickness 10~55nm der,
The tin-doped indium oxide layer has a refractive index of 1.85 to 2.35 and a film thickness of 5 to 50 nm.
The transparent conductive film whose tearing force prescribed | regulated to JISK7128-1 is 0.3 (N) or more .