TWI527061B - Transparent conductive film and touch panel - Google Patents

Description

Transparent conductive film and touch panel

The present invention relates to a transparent conductive film having good visibility and a touch panel having the transparent conductive film.

In recent years, a transparent conductive film in which a transparent conductive film is provided on a base film such as a polyester film is used for a touch panel application or the like. Generally, a thin film of a metal oxide such as indium tin oxide (ITO) is used as the transparent conductive film, and it can be laminated on the base film by sputtering or vacuum deposition.

In terms of the operation mode of the touch panel, the resistive film type is the mainstream, but in recent years, the electrostatic capacity type is rapidly spreading. The transparent conductive film used for the resistive touch panel is generally composed of a transparent conductive film (a transparent conductive film covering one surface of the substrate) which is not patterned. On the other hand, as the electrostatic capacitance type touch panel, a transparent conductive film in which a patterned transparent conductive film is laminated can be generally used.

The transparent conductive film used in the capacitive touch panel is usually patterned by photolithography or the like, and the transparent conductive film is patterned to have a pattern portion and a non-pattern portion of the transparent conductive film in plan view.

When a capacitance type touch panel using such a transparent conductive film in which a transparent conductive film is patterned is used, the pattern portion of the transparent conductive film can be visually recognized, which is a problem of the phenomenon of "perspective". This "perspective" phenomenon reduces the quality that is required as a display device.

Therefore, there has been proposed a perspective for suppressing the pattern of a transparent conductive film (for example, Patent Documents 1 to 6).

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2011-84075

Patent Document 2 Japanese Patent Laid-Open Publication No. 2010-228295

Patent Document 3 Japanese Patent Laid-Open Publication No. 2009-76432

Patent Document 4 Japanese Patent Laid-Open Publication No. 2006-301510

Patent Document 5 Japanese Patent No. 4661995

Patent Document 6 Japanese Patent No. 4364938

However, in the techniques disclosed in Patent Documents 1 to 6, the perspective suppressing effect of the transparent conductive film pattern is not completely satisfactory. Particularly in the electrostatic capacitance type touch panel, since the transparent conductive film is used for the incident surface side of the light, the above-mentioned see-through phenomenon lowers the quality which is required as a display device, and further improvement is required.

Therefore, an object of the present invention is to provide a transparent conductive film in which the visual recognition (perspective) of the transparent conductive film pattern is sufficiently suppressed. Further, another object of the present invention is to provide a touch panel comprising a transparent conductive film in which a transparent conductive film pattern is sufficiently visually recognized (perspective).

The transparent conductive film of the present invention which can achieve the above-mentioned problems is such that the substrate film having a refractive index of 1.61 to 1.70 has a refractive index of 1.50 to 1.60 on one or both sides and an optical thickness of one side of each substrate film. The first layer of (1/4) λ, the second layer of refractive index of 1.61 to 1.80, and refraction a third layer having a ratio of 1.50 or less and a transparent conductive film having a refractive index of 1.81 or more, and a total of optical thicknesses of the second layer on one side of each of the base film and optical thickness of the third layer It is (1/4)λ.

However, λ is 380 to 780 nm.

Further, the touch panel of the present invention comprises the transparent conductive film of the present invention.

According to the present invention, it is possible to provide a transparent conductive film in which the see-through phenomenon is sufficiently suppressed. The transparent conductive film of the present invention is suitable for use in a touch panel, and is particularly suitable for use in an electrostatic capacitance type touch panel.

In the transparent conductive film of the present invention, the first layer, the second layer, the third layer, and the transparent conductive film are sequentially provided on one surface or both surfaces of the base film.

In the present invention, the first layer, the second layer, the third layer, the transparent conductive film, and the SiO ₂ film or the hard coat layer which are provided as necessary include a form and a setting which are provided only on one side of the base film. The shape on both sides.

Hereinafter, each constituent element constituting the transparent conductive film of the present invention will be described in detail.

[Substrate film]

The base film of the present invention has a refractive index (nf) of 1.61 to 1.70. Such a substrate film is preferably a polyester film, and particularly preferably a polyethylene terephthalate film.

The refractive index (nf) of the base film is preferably in the range of 1.62 to 1.69, more preferably in the range of 1.63 to 1.68, and particularly preferably in the range of 1.64 to 1.67.

The thickness of the base film is suitably in the range of 20 to 300 μm, preferably in the range of 50 to 250 μm, and more preferably in the range of 50 to 200 μm.

[Layer 1]

The refractive index (n1) of the first layer of the present invention is in the range of 1.50 to 1.60. The refractive index (n1) of the first layer is preferably in the range of 1.51 to 1.60, more preferably in the range of 1.52 to 1.59, and particularly preferably in the range of 1.55 to 1.59.

It is important to satisfy (1/4) λ for the optical thickness of one side of each of the base film of the first layer. Here, the optical thickness of one side of each substrate film is the product of the refractive index (n1) of the first layer and the thickness (d1) of one side of each substrate film, and λ means the wavelength range of the visible light region 380~ 780nm. The unit of the thickness (d1) of the first layer is nm. In the present invention, the unit of the optical thickness is nm, and is a value obtained by rounding off the decimal point.

That is, the optical thickness of the first layer must satisfy the following relational expression 1.

(380 nm / 4) ≦ (n1 × d1) ≦ (780nm / 4) 95nm ≦ (n1 × d1) ≦ 195nm ... ... (Formula 1)

That is, when the refractive index of the first layer is 1.50, the thickness d1 is in the range of 63 to 130 nm, and when the refractive index of the first layer is 1.60, the thickness d1 is in the range of 59 to 122 nm.

Further, the range of λ is preferably 450 to 650 nm. That is, the optical thickness of the first layer preferably satisfies the following relational expression 2.

(450 nm / 4) ≦ (n1 × d1) ≦ (650 nm / 4) 113 nm ≦ (n1 × d1) ≦ 163 nm ... (Formula 2).

Further, the range of λ is preferably 500 to 600 nm. That is, the optical thickness of the first layer is more preferably such that the following relational expression 3 is satisfied.

(500 nm / 4) ≦ (n1 × d1) ≦ (600 nm / 4) 125 nm ≦ (n1 × d1) ≦ 150 nm ... (Formula 3).

The first layer is preferably a layer mainly composed of a resin. In other words, the resin is preferably contained in an amount of 50% by mass or more based on 100% by mass of the total solid content of the first layer, more preferably 60% by mass or more, particularly preferably 70% by mass or more, and most preferably contained. 80% by mass or more is optimal. The upper limit is preferably 99% by mass or less, more preferably 98% by mass or less, and particularly preferably 95% by mass or less.

As such a resin, a polyester resin, an acrylic resin, or a urethane resin is suitably used. Among these resins, a polyester resin is preferable, and a polyester resin having a naphthalene ring in a molecule is further preferably used.

The first layer preferably contains a crosslinking agent from the viewpoint of imparting an easy adhesion function to the first layer described later. As such a crosslinking agent, a melamine crosslinking agent can be mentioned. Oxazoline crosslinking agent, carbodiimide crosslinking agent, isocyanate crosslinking agent, nitrogen A crosslinking agent or an epoxy crosslinking agent. Among these, it is suitable to use a melamine crosslinking agent, An oxazoline crosslinking agent or a carbodiimide crosslinking agent.

The content of the crosslinking agent in the first layer is preferably in the range of 1 to 40% by mass, more preferably in the range of 3 to 35% by mass, based on 100% by mass of the total solid content of the first layer, and particularly preferably 5 to 30% by mass range.

In order to further improve the slipperiness or the adhesion resistance, the first layer preferably contains organic or inorganic particles. The particles are not particularly limited, and examples thereof include inorganic particles such as citric acid gel, titanium oxide, aluminum oxide, zirconium oxide, calcium carbonate, carbon black, and zeolite particles, or acrylic particles, polyfluorene oxide particles, and poly Organic particles such as quinoneimine particles, Teflon (registered trademark) particles, crosslinked polyester particles, crosslinked polystyrene particles, crosslinked polymer particles, and core-shell particles. Among these particles, a citric acid gel is suitably used.

The content of the particles in the first layer is preferably in the range of 0.05 to 8% by mass, and more preferably in the range of 0.1 to 5% by mass, based on 100% by mass of the total solid content of the first layer.

The first layer preferably has a function as an easy-adhesion layer. That is, the first layer preferably has adhesion (adhesion) for reinforcing the layer on the base film and the first layer (for example, the second layer, the third layer, and the transparent conductive film) as The function of the easy adhesion layer is better. Therefore, the first layer is preferably disposed directly on the substrate film.

The first layer is preferably laminated on the substrate film by a wet coating method. In particular, it is preferable to laminate the first layer in the production step of the base film, which is a so-called "series coating method". When the first layer is coated on the base film, it is preferred to subject the surface of the base film to corona discharge treatment, flame treatment, plasma treatment, or the like as a pretreatment for improving coatability or adhesion.

In the above wet coating method, for example, a coating method such as a reverse coating method, a spray coating method, a bar coating method, a gravure coating method, a rod coating method, a die coating method, a spin coating method, or an extrusion coating method can be used.

In the above-described tandem coating method, a film using a polyethylene terephthalate (hereinafter abbreviated as PET) film as a base film will be described below, but the present invention is not limited thereto.

PET pellets having a final viscosity of 0.5 to 0.8 dl/g as a raw material of the PET film were vacuum dried. The vacuum dried pellets were supplied to an extruder and melted at 260 to 300 °C. The molten PET polymer is extruded into a sheet shape by a T-shaped nozzle, and is wound on a mirror-casting drum having a surface temperature of 10 to 60 ° C by a casting method using static electricity, and is cooled and solidified. An unstretched PET film was made. The unstretched PET film is extended 2.5 to 5 times in the longitudinal direction (referred to as the traveling direction of the film, also referred to as "longitudinal direction") between the rolls heated to 70 to 100 °C. In the air, at least one side of the uniaxially stretched PET film obtained by the stretching was subjected to a corona discharge treatment to have a surface wet tension of 47 mN/m or more. The coating liquid of the first layer was applied to the treated surface.

Next, the uniaxially stretched PET film coated with the coating liquid was sandwiched with a jig and guided to a drying zone, and dried at a temperature less than the Tg of the uniaxially stretched PET film. Next, the temperature is raised to a temperature higher than Tg, and the film is again dried at a temperature near Tg. Then, the film is continuously extended in the heating zone of 70 to 150 ° C for 2.5 to 5 times in the lateral direction (the direction orthogonal to the traveling direction of the film, also referred to as "width direction"). Next, the film is heat-treated for 5 to 40 seconds in a heating zone of 180 to 240 ° C to obtain a PET film having a first layer laminated on the PET film which is finished in the crystal alignment. Further, in the above heat treatment, it is also necessary to carry out a relaxation treatment of 3 to 12% as necessary. The biaxial extension may be either longitudinal or transverse extension, or simultaneous extension of the two axes, and may be extended in either the longitudinal or transverse direction after the longitudinal and lateral extension.

[Layer 2]

The refractive index (n2) of the second layer is 1.61 to 1.80. The refractive index (n2) of the second layer is preferably in the range of 1.63 to 1.79, more preferably in the range of 1.65 to 1.78, and particularly preferably in the range of 1.65 to 1.75.

The thickness (d2) of one surface of each of the base film of the second layer is preferably 20 nm or more, more preferably 25 nm or more, and particularly preferably 30 nm or more. The upper limit is preferably 80 nm or less, more preferably 70 nm or less, particularly preferably 60 nm or less, and most preferably 50 nm or less.

The second layer is preferably a layer containing a resin and a metal oxide, a layer containing a high refractive index resin, or a layer containing a metal oxide and a high refractive index resin, and particularly preferably a layer containing a resin and a metal oxide.

Further, the second layer is preferably a composition containing a resin and a metal oxide, a composition containing a high refractive index resin, or a composition containing a metal oxide and a high refractive index resin by a wet coating method. A layer obtained by hardening it is preferred. Particularly preferred is a layer obtained by coating and curing a composition containing a resin and a metal oxide by a wet coating method. The aforementioned coating method can be used as the wet coating method.

The composition for forming a layer containing a resin and a metal oxide will be described below.

The resin component is preferably a thermosetting resin or an active energy ray curable resin, and particularly preferably an active energy ray curable resin.

The active energy ray-curable resin is preferably a monomer or oligomer having at least one ethylenically unsaturated group in the molecule, which is cured by an active energy ray such as ultraviolet rays or electron beams. Here, examples of the ethylenically unsaturated group include an acrylic group, a methacryl group, a vinyl group, an allyl group and the like.

Examples of the above monomers include methyl (meth)acrylate, lauryl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, and methoxytriethylene glycol (A). Acrylate, phenoxyethyl (meth)acrylate, tetrahydrofuran methyl (meth)acrylate, isobornyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, (methyl) Monofunctional acrylate such as 2-hydroxypropyl acrylate or 2-hydroxy-3-phenoxy (meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol II (Methacrylate Ester, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(methyl) Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tri(meth) acrylate, tripentaerythritol hexa(methyl) triacrylate, trimethylolpropane ( Polyfunctional acrylate such as methyl acrylate benzoate, trimethylolpropane benzoate, glycerol di(meth) acrylate hexamethylene diisocyanate, pentaerythritol tri(meth) acrylate hexamethylene A urethane acrylate such as a diisocyanate.

Examples of the above oligomers include polyester (meth) acrylate, poly urethane (meth) acrylate, epoxy (meth) acrylate, and polyether (meth) acrylate. Ester, alkyd (meth) acrylate, melamine (meth) acrylate, poly methoxy (meth) acrylate, and the like.

The above monomers or oligomers may be used singly or in combination of two or more, but it is preferred to use a trifunctional or higher polyfunctional monomer or a polyfunctional oligomer.

In the case of the metal oxide, metal oxide fine particles having a refractive index of 1.65 or more are preferable, and metal oxide fine particles having a refractive index of 1.7 to 2.8 are particularly preferably used. Examples of such metal oxide fine particles include metal oxide particles such as titanium, zirconium, zinc, tin, antimony, bismuth, iron, and indium. Specific examples of the metal oxide fine particles include titanium oxide, zirconium oxide, zinc oxide, tin oxide, antimony oxide, antimony oxide, iron oxide, zinc antimonate, tin oxide doped indium oxide (ITO), and锑 doped tin oxide (ATO), phosphorus-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, fluorine-doped tin oxide, etc., and the metal oxide fine particles may be used singly or in combination. Among the above metal oxide fine particles, especially oxidation Titanium and zirconia are suitable because they do not lower the transparency and increase the refractive index of the second layer.

The content of the metal oxide in the composition is preferably 30% by mass or more, more preferably 40% by mass or more, and particularly preferably 50% by mass or more, based on 100% by mass of the total solid content of the composition. 55 mass% or more. The upper limit is preferably 95% by mass or less, more preferably 90% by mass or less, and particularly preferably 85% by mass or less.

The content ratio of the resin component to the metal oxide in the composition is preferably from 50 to 900 parts by mass, more preferably from 100 to 800 parts by mass, based on 100 parts by mass of the resin component.

The composition preferably contains a photopolymerization initiator. As a specific example of such a photopolymerization initiator, for example, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone can be used. , diphenyl ketone, 2-chlorodiphenyl ketone, 4,4'-dichlorodiphenyl ketone, 4,4'-bisdiethylaminodiphenyl ketone, mischrone, benzyl, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methotrexate, p-isopropyl-α-hydroxyisobutyl benzophenone, α-hydroxyisobutyl benzophenone, 2, 2 - a carbonyl compound such as dimethoxy-2-phenylacetophenone or 1-hydroxycyclohexyl phenyl ketone, tetramethylammonium thioformyl monosulfide, tetramethylammoniothiodisulfide, thiophene A sulfur compound such as ketone, 2-chlorothioxanthone or 2-methylthioxanthone. These photopolymerization initiators may be used singly or in combination of two or more.

The content of the photopolymerization initiator is preferably in the range of 0.1 to 10% by mass, and preferably in the range of 0.5 to 8% by mass, based on 100% by mass of the total solid content of the composition.

A description will be given of a composition for forming a layer containing a high refractive index resin.

The high refractive index resin includes a resin containing a halogen atom other than fluorine (for example, a resin containing a bromine atom, a resin containing a chlorine atom, a resin containing an iodine atom), a resin containing a sulfur atom, and a resin containing a nitrogen atom. A resin containing a phosphorus atom, a resin containing an aromatic ring (for example, a resin containing an anthracene skeleton, a resin containing a phenyl group, or the like). These resins may be any resin having transparency, and a known or commercially available resin may be used, or may be used in combination with other resins.

For the halogen atom other than fluorine, for example, a brominated acrylic resin, a brominated urethane resin, a brominated polyester resin, a brominated polyether resin, or a bromination can be used as the resin containing a bromine atom or a chlorine atom. Epoxy resin, brominated spiral acetal resin, brominated polybutadiene resin, brominated polythiol polyene resin, chlorinated acrylic resin, chlorinated urethane resin, chlorinated polyester resin, chlorine Polyether resin, chlorinated epoxy resin, and the like. For the raw material component of the resin containing a bromine atom, for example, the phenyl group of the acrylate may be used. A compound obtained by bromination in the opposite position. As the commercial product, for example, BR-42 manufactured by Dai-ichi Kogyo Co., Ltd. can be used as the substance. For other commercially available products, BR-42M, BR-30M, BR-31, etc., manufactured by Dai-Il Pharmaceutical Co., Ltd., RDX51027 manufactured by DAICEL-CYTEC Co., Ltd., or the like can be used. In addition, as the resin containing a chlorine atom, a benzyl chloride salt of N,N-dimethylaminoethyl methacrylate or the like may be used, or two or more kinds thereof may be used in combination.

As the resin containing a sulfur atom, for example, S,S'-ethylene bis(thio(meth)acrylate), S,S'-(thiodiethylene)bis(thio(meth)acrylic acid) can be used. Ester), S, S'-[thiobis(diethylene sulfide)] bis (thio (meth) acrylate), S, S'- (oxydiethylene) bis (thio (meth) acrylate), etc. . Here, sulfur (meth) acrylate means thiomethacrylate and sulfur acrylate.

Among these, S, S'-ethylene bis(thiomethacrylate), S, S'-(thiodiethylene) bis(thiomethacrylate) is suitably used. S,S'-ethylene bis(thiomethacrylate) can be obtained by reacting 1,2-ethanedithiol with an alkali metal compound and causing the obtained alkali metal salt of 1,2-ethanedithiol A method in which methacrylic acid ruthenium chloride is reacted in a non-polar organic solvent or the like is produced. Further, as S,S'-(thiodiethylene) bis(thiomethacrylate), a commercially available product of S2EG, manufactured by Nippon Shokubai Co., Ltd., can be used.

Further, as the resin containing a sulfur atom and an aromatic ring, for example, S, S'-(thiodi-p-phenylene) bis(thio(meth)acrylate), S,S'-[4 can be used. , 4'-thiobis(3-chlorophenyl)] bis(thio(meth)acrylate), S,S'-[4,4'-thiobis(3,5-dichlorobenzene)] (sulfur ( Methyl)acrylate), S,S'-[4,4'-thiobis(3-bromobenzene)](sulfur (meth)acrylate), S,S'-[4,4'-sulfur double (3,5-dibromobenzene)] (sulfur (meth) acrylate), S, S'-[4,4'-thiobis(3-methylphenyl)] bis(thio(meth)acrylate ), S, S'-[4,4'-thiobis(3,5-dimethylphenyl)] (sulfur (meth) acrylate), S, S'-[4,4'-thiobis ( 3-methylbenzene)] bis (thio (meth) acrylate) or the like. Among these, S, S'-(thiodi-p-phenylene) bis(thiomethacrylate) (MPSMA made by Sumitomo Seika Co., Ltd.) is suitable, but it can be made by making 4,4'-thiodiphenyl The thiol is reacted with an alkali metal compound, and the obtained alkali metal salt of 4,4'-thiodiphenylthiol is reacted with methacrylic acid ruthenium chloride in a nonpolar organic solvent.

As the resin containing an aromatic ring, an acrylic resin having a 9,9-bisphenoxyfluorene skeleton, an acrylic resin having a biphenyl group, an epoxy resin, or the like can be used. For example, 9,9-bis[4-(2-propenyloxyethoxy)phenyl"anthracene (NK Ester A-BPEF), o-phenylphenol glycidyl ether acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) can be used. NK Ester 401P), hydroxyethylated o-phenylphenol acrylate (NK Ester A-LEN-10), 9,9-bis(3-methyl-4-hydroxyphenyl)fluorene (BCF) manufactured by JFE Chemical Co., Ltd. 9,9-bis[4-(2-hydroxyethoxy)phenyl]indole (BPEF), bisphenol hydrazine diglycidyl ether (BPFG) manufactured by Osaka Gas Chemical Co., Ltd., bisphenoxyethanol hydrazine diglycidyl Ether (BPEFG), bisphenoxyethanol oxime diacrylate (BPEF-A), Ogsol PG series, Ogsol EG series, Ogsol EA series, Ogsol EA-F series, ONCOAT EX series manufactured by Nagase Industrial Co., Ltd., Kyoeisha Chemical Co., Ltd. HIC-G series made by the company, RF (X) series made by ADEKA company, etc.

The high refractive index resin is preferably a polymerizable monomer or a polymerizable oligomer containing a polymerizable group such as an acrylic group or an epoxy group, as described above.

The composition preferably contains a high refractive index resin and a resin component (preferably an active energy ray curable resin) used to form a composition for forming a layer containing the resin and the metal oxide. The content of the resin component is preferably in the range of 5 to 50 parts by mass, preferably in the range of 10 to 40 parts by mass, based on 100 parts by mass of the high refractive index resin.

The content of the high refractive index resin in the composition is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more based on 100% by mass of the total solid content of the composition. The upper limit is preferably 95% by mass or less, preferably 90% by mass or less.

The composition preferably further contains a photopolymerization initiator, and the content thereof is preferably in the range of 0.1 to 10% by mass, preferably 0.5 to 8% by mass based on 100% by mass based on the total of the solid content of the composition. .

Next, a description will be given of a composition for forming a layer containing a metal oxide and a high refractive index resin. This composition is used by combining the aforementioned metal oxide and a high refractive index resin. The content ratio (mass ratio) of the metal oxide to the high refractive index resin is preferably in the range of metal oxide: high refractive index resin = 9:1 to 1:9, more preferably in the range of 8:2 to 2:8. Very good for the range of 7:3~3:7.

The composition preferably further contains a resin component (preferably an active energy ray-curable resin) used for forming a composition containing the layer of the resin and the metal oxide. The content of the resin component is preferably in the range of 5 to 50% by mass, more preferably in the range of 10 to 40% by mass, particularly preferably in the range of 20 to 40% by mass, based on 100% by mass of the total solid content of the composition. .

The composition preferably further contains a photopolymerization initiator, and the content thereof is preferably in the range of 0.1 to 10% by mass, preferably 0.5 to 8% by mass based on 100% by mass based on the total of the solid content of the composition. .

[Layer 3]

The refractive index (n3) of the third layer is 1.50 or less. The refractive index (n3) of the third layer is preferably 1.46 or less, more preferably 1.40 or less, and particularly preferably 1.38 or less. The lower limit is preferably 1.25 or more, more preferably 1.30 or more.

The thickness (d3) of one surface of each of the base film of the third layer is preferably in the range of 5 to 50 nm, more preferably in the range of 10 to 40 nm.

The third layer is preferably a layer obtained by applying a thermosetting or active energy ray-curable composition by a wet coating method and hardening it. The aforementioned coating method can be used as the wet coating method.

The thermosetting composition is, for example, a composition containing a cerium oxide polymer formed by combining cerium oxide-based fine particles as a main component. Such a composition is, in detail, a cerium oxide component of cerium oxide-based fine particles and a cerium oxide polymer of a precursor, and is homogenized; and a cerium oxygen formed by combining cerium oxide-based fine particles The alkylene polymer can be temporarily formed into a sterol compound by a known hydrolysis reaction of a polyfunctional decane compound in a solvent in the presence of the cerium oxide-based fine particles in a solvent, and then known by utilization. Obtained by the condensation reaction.

The active energy ray-curable composition includes, for example, an active energy ray-curable resin which is cured by an active energy ray such as an ultraviolet ray or an electron beam; and a low refractive index inorganic particle which is a low refractive index material. And/or a composition of a fluorine-containing compound.

The third layer is preferably a film having a thickness (d3) of 50 nm or less, and is formed into an active energy ray hardening composition from the viewpoint that the film can be formed uniformly and precisely by a wet coating method. A composition containing an active energy ray-curable resin and a fluorine-containing compound is suitably used. As the composition, all or a part of the active energy ray-curable resin may be a fluorine-containing monomer and/or a fluorine-containing oligomer described later.

In the active energy ray-curable resin, the same thing as the substance used in the second layer (a monomer or oligomer having at least one ethylenically unsaturated group in the molecule) can be used. The description is omitted. another In addition, the photopolymerization initiator which can be used together with the active energy ray-curable resin may be the same as those used for the second layer, and thus the description thereof is omitted.

In the active energy ray-curable composition, the content of the active energy ray-curable resin is suitably from 5 to 90% by mass, preferably from 5 to 90% by mass based on the total amount of the solid content of the composition. The range of 80% by mass, more preferably 10% to 70% by mass.

The inorganic particles having a low refractive index are preferably inorganic particles such as cerium oxide or magnesium fluoride. Further, the inorganic particles are preferably hollow or porous. The refractive index of the above inorganic particles is more preferably in the range of 1.2 to 1.35.

In the active energy ray-curable composition, the content of the low refractive index inorganic particles is preferably in the range of 20 to 80% by mass, more preferably 30 to 70% by mass based on 100% by mass of the total solid content of the composition. The scope.

Examples of the fluorine-containing compound include a fluorine-containing monomer, a fluorine-containing oligomer, and a fluorine-containing polymer compound. Here, the fluorine-containing monomer or the fluorine-containing oligomer is a monomer or oligomer having an ethylenically unsaturated group and a fluorine atom in the molecule.

Examples of the fluorine-containing monomer and the fluorine-containing oligomer include, for example, (meth)acrylic acid-2,2,2-trifluoroethyl ester, (meth)acrylic acid-2,2,3,3,3. - pentafluoropropyl ester, 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluoro) (meth)acrylate Fluorine-containing (meth) acrylate such as octyl)ethyl ester, (meth)acrylic acid-2-(perfluorodecyl)ethyl ester, (meth)acrylic acid-β-(perfluorooctyl)ethyl ester Class, bis-(α-fluoroacrylic acid)-2,2,2-trifluoroethyl glycol, bis-(α-fluoroacrylic acid)-2,2,3,3,3- Pentafluoropropyl glycol, di-(α-fluoroacrylic acid)-2,2,3,3,4,4,4-hexafluorobutyl glycol, di-(α-fluoroacrylic acid)-2, 2,3,3,4,4,5,5,5-nonafluoropentyl glycol, di-(α-fluoroacrylic acid)-2,2,3,3,4,4,5,5,6 ,6,6-undefluorohexylethylene glycol, di-(α-fluoroacrylic acid)-2,2,3,3,4,4,5,5,6,6,7,7,7-13 Fluoroheptyl glycol, di-(α-fluoroacrylic acid)-2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl Ethylene glycol, di-(α-fluoroacrylic acid)-3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl glycol, two -(α-fluoroacrylic acid)-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorodecyl glycol Equivalent bis-(α-fluoroacrylic acid) fluoroalkyl esters.

The fluorine-containing polymer compound may, for example, be a fluorine-containing copolymer having a fluorine-containing monomer and a monomer for imparting a crosslinkable group as a constituent unit. Specific examples of the fluoromonomer unit are, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethylidene). Partial or fully fluorinated alkyl ester derivatives of (meth)acrylic acid (such as Viscoat 6FM (Osaka Organic Chemicals) or M-2020 (Daikin) (), etc.), fully or partially fluorinated vinyl ethers, and the like. The monomer for imparting a crosslinkable group may, for example, be a (meth) acrylate monomer having a crosslinkable functional group in the molecule as in the case of glycidyl methacrylate, and further includes a (meth) acrylate monomer having a carboxyl group or a hydroxyl group, an amine group, a sulfonic acid group or the like (for example: (meth)acrylic acid, hydroxymethyl (meth)acrylate, hydroxyalkyl (meth)acrylate, acrylic acid acryl) Ester, etc.).

In the active energy ray-curable composition, the content of the fluorine-containing compound in an amount of 100% by mass based on the total solid content of the composition is preferably 30% by mass or more, more preferably 50% by mass or more, and particularly preferably 60% by mass. quality% the above. The upper limit is preferably 100% by mass or less, more preferably 99% by mass or less, and particularly preferably 98% by mass or less.

[Total of the optical thickness of the second layer and the optical thickness of the third layer]

It is important that the total of the optical thickness of the second layer on one side of each base film and the optical thickness of the third layer satisfy (1/4) λ. The optical thickness is a product of a refractive index and a thickness as described above, and the λ is also in the visible light region wavelength range of 380 to 780 nm as described above. The unit of thickness is nm.

That is, the total of the optical thickness of the second layer and the optical thickness of the third layer must satisfy the following relational expression 4.

(380 nm / 4) ≦ (n2 × d2) + (n3 × d3) ≦ (780 nm / 4) 95 nm ≦ (n2 × d2) + (n3 × d3) ≦ 195 nm ... (Formula 4).

That is, the total of the optical thickness (n2 × d2) of the second layer and the optical thickness (n3 × d3) of the third layer must be 95 nm or more and 195 nm or less.

Further, the total of the optical thickness of the second layer and the optical thickness of the third layer is preferably in the range of 95 to 163 nm, more preferably in the range of 95 to 150 nm, and particularly preferably in the range of 100 to 140 nm.

[Method of Forming Layer 2 and Layer 3]

A method of coating and laminating the second layer and the third layer by a wet coating method will be described.

The second layer and the third layer may be layer-by-layer coated by a wet coating method, or may be simultaneously applied by a wet coating method, or may be applied once by a wet coating method. It is formed by separating its layers.

The method of laminating by layer by wet coating method is to wet-coat the second layer, and if necessary, it is dried and hardened, and then The third layer is wet-coated and formed by drying and hardening as necessary. The formation of the second layer and the third layer can be carried out by separate steps, or can be carried out continuously by a single step.

By a method of simultaneous coating by a wet coating method, a coating method capable of simultaneously performing a layer coating method, for example, using a multilayer slit die coater, a multilayer slide bead coater, an extrusion die coater, etc., while simultaneously laminating coating The second layer and the third layer, and the method of drying and hardening as necessary.

A method of forming a single coating liquid by a wet coating method and then separating the layers is described in, for example, JP-A-2008-7414, JP-A-2008-7415, and JP-A-2009 Japanese Laid-Open Patent Publication No. 2009-75576, Japanese Laid-Open Patent Publication No. 2009- 1987-A Nos. , can refer to these methods to use.

[Transparent Conductive Film]

As the material of the transparent conductive film, a well-known material used for the electrode of the touch panel can be used. For example, metal oxides such as tin oxide, indium oxide, antimony oxide, zinc oxide, ITO (indium tin oxide), and ATO (tantalum tin oxide) can be cited. Among these, ITO is suitably used.

The thickness of the transparent conductive film is preferably 10 nm or more, more preferably 15 nm or more, and particularly preferably 20 nm or more, from the viewpoint of ensuring good electrical conductivity of the surface resistance value of 10 ³ Ω/□ or less. On the other hand, when the thickness of the transparent conductive film is too large, the effect of suppressing the see-through phenomenon is reduced and the transparency is lowered. Therefore, the upper limit of the thickness of the transparent conductive film is preferably 60 nm or less. It is preferably 50 nm or less, and particularly preferably 40 nm or less.

The refractive index (nt) of the transparent conductive film is 1.81 or more. Further, the refractive index (nt) of the transparent conductive film is preferably 1.85 or more, more preferably 1.90 or more. The upper limit is preferably 2.20 or less, more preferably 2.10 or less.

The method for forming the transparent conductive film is not particularly limited, and a conventionally known method can be used. Specifically, a dry procedure such as a vacuum deposition method, a sputtering method, or an ion plating method can be used.

The transparent conductive film of the present invention is patterned. For example, the transparent conductive film obtained by forming the film as described above is patterned. The patterning can be formed into various patterns depending on the application to which the transparent conductive film is applied. Further, the pattern portion and the non-pattern portion can be formed by patterning the transparent conductive film, and the shape of the pattern portion may be, for example, a strip shape or a lattice shape.

The patterning of the transparent conductive film is generally performed by etching. For example, after forming a patterned etching resist film on a transparent conductive film by photolithography, laser exposure, or printing, the transparent conductive film can be patterned by etching.

As the etching liquid, a conventionally known substance can be used. For example, an inorganic acid such as hydrogen chloride, hydrogen bromide, sulfuric acid, nitric acid or phosphoric acid, an organic acid such as acetic acid, or the like, and an aqueous solution thereof can be used.

[SiO ₂ film]

In the present invention, it is preferred to provide a SiO ₂ film between the third layer and the transparent conductive film. The SiO ₂ film can be laminated by a dry process using a vacuum deposition method, a sputtering method, an ion plating method, a plasma CVD method, or the like, or by coating a ruthenium sol or the like by a wet coating method. The method or the like is formed. Among these, a dry procedural method is preferred.

The refractive index (ns) of the SiO ₂ film is preferably in the range of 1.43 to 1.50, more preferably in the range of 1.45 to 1.49.

The thickness (ds) of one surface of each of the base film of the SiO ₂ film is preferably in the range of 5 to 60 nm, more preferably in the range of 10 to 50 nm, and particularly preferably in the range of 10 to 40 nm.

When the SiO ₂ film is provided, the total of the optical thickness of the second layer on one side of each of the base film, the optical thickness of the third layer, and the optical thickness of the SiO ₂ film preferably satisfy (1/4) λ. The optical thickness is a product of a refractive index and a thickness as described above, and the λ is a wavelength range of 380 to 780 nm in the visible light region as described above. The unit of thickness is nm.

That is, the total of the optical thickness of the second layer, the optical thickness of the third layer, and the optical thickness of the SiO ₂ film is preferably such that the following relational expression 5 is satisfied.

(380nm/4)≦(n2×d2)+(n3×d3)+(ns×ds)≦(780nm/4)

95 nm ≦ (n2 × d2) + (n3 × d3) + (ns × ds) ≦ 195 nm ... (Formula 5).

Further, the range of λ is preferably from 450 to 650 nm. That is, the total of the optical thicknesses is more preferably to satisfy the following relational expression 6.

(450nm/4)≦(n2×d2)+(n3×d3)+(ns×ds)≦(650nm/4)

113 nm ≦ (n2 × d2) + (n3 × d3) + (ns × ds) ≦ 163 nm (...).

Further, further, the range of λ is more preferably 500 to 600 nm. That is, the total of the optical thicknesses is particularly preferably in the following relationship.

(500nm/4)≦(n2×d2)+(n3×d3)+(ns×ds)≦(600nm/4)

125 nm ≦ (n2 × d2) + (n3 × d3) + (ns × ds) ≦ 150 nm (...).

By providing the SiO ₂ film between the third layer and the transparent conductive film, the adhesion of the transparent conductive film can be improved, and further, by making the optical thickness of the SiO ₂ film within the above range, the see-through phenomenon can be suppressed.

[hard coating]

In the present invention, a hard coat layer may be provided between the first layer and the second layer. The thickness of the hard coat layer is preferably 0.5 μm or more, more preferably 1 μm or more. The upper limit of the thickness is preferably 10 μm or less, more preferably 8 μm or less, still more preferably 5 μm or less, and particularly preferably 3 μm or less.

In the case where a hard coat layer is provided between the first layer and the second layer, the refractive index (nh) of the hard coat layer, the refractive index (n1) of the first layer, and the refractive index (nf) of the base film are preferably nf. >n1>nh. In particular, the refractive index difference (nf-n1) between the base film and the first layer and the refractive index difference (n1-nh) between the first layer and the hard coat layer are preferably 0.1 or less, more preferably 0.09 or less, and particularly preferably It is below 0.08. The lower limit is preferably 0.03 or more, more preferably 0.04 or more. In this way, the reflection stain of the transparent conductive film can be alleviated.

In the present invention, the first layer, the second layer, the third layer, the transparent conductive film, and the SiO ₂ film or the hard coat layer are preferably provided on one surface of the base film, preferably in the opposite direction. Set a hard coat on one side. Thereby, the oligomer can be suppressed from being deposited from the base film. In this case, from the viewpoint of reducing the reflection color unevenness of the transparent conductive film, it is preferred to provide a first layer between the base film and the hard coat layer so as to satisfy the relationship of the above refractive index.

In the present invention, it is more preferable to sequentially provide the first layer and the hard coat layer on both surfaces of the base film, and the refractive index (nf) of the base film on both sides, the refractive index (n1) of the first layer, and the hard coat layer. The refractive index (nh) is preferably such that the above relationship is satisfied. In this form, the following configurations (1) and (2) are exemplified. Further, in the following configuration examples, the transparent conductive film is a patterned transparent conductive film, and other layers than the transparent conductive film are not patterned.

(1) Hard coat layer / 1st layer / base film / 1st layer / hard coat layer / 2nd layer / 3rd layer / transparent conductive film

(2) Transparent conductive film / 3rd layer / 2nd layer / hard coat layer / 1st layer / base film / 1st layer / hard coat layer / 2nd layer / 3rd layer / transparent conductive film

The refractive index (nh) of the hard coat layer is suitably in the range of 1.46 to 1.55, preferably in the range of 1.48 to 1.54, more preferably in the range of 1.50 to 1.53.

Further, the above hard coat layer may be colored by containing a coloring dye or a coloring pigment. Thereby, the reflection color or the penetration color of the transparent conductive film can be adjusted.

The hard coat layer is preferably a layer obtained by applying a composition containing a thermosetting or active energy ray-curable resin by a wet coating method, and then drying it and then hardening it. In the composition for forming a hard coat layer, a composition containing an active energy ray-curable resin is particularly preferable. In the case of the wet coating method, the aforementioned coating method can be used.

The active energy ray-curable resin can be the same as those used for the second layer, and thus the description thereof is omitted. In addition, a photopolymerization initiator which can be used in combination with an active energy ray-curable resin The same substances as those used in the second layer described above can be used, and thus the description thereof is omitted.

[Transparent Conductive Film]

The transparent conductive film of the present invention has a first layer, a second layer, a third layer, and a transparent conductive film in this order on one side or both sides of the base film. Further, a SiO ₂ film or a hard coat layer may be provided on one or both sides of the base film as necessary. It is especially preferred to provide a hard coat layer on both sides.

Several suitable examples of the transparent conductive film of the present invention are listed below, but the present invention is not limited thereto. Further, in the following configuration examples, the transparent conductive film is a patterned transparent conductive film. The layers other than the transparent conductive film are not patterned.

(a) Substrate film / layer 1 / layer 2 / layer 3 / transparent conductive film

(b) 1st layer/substrate film/1st layer/2nd layer/3rd layer/transparent conductive film

(c) Hard coat layer / 1st layer / base film / 1st layer / 2nd layer / 3rd layer / transparent conductive film

(d) 1st layer/substrate film/1st layer/hard coat layer/2nd layer/3rd layer/transparent conductive film

(e) Hard coat layer / 1st layer / base film / 1st layer / hard coat layer / 2nd layer / 3rd layer / transparent conductive film

(f) Transparent Conductive Film / Layer 3 / Layer 2 / Layer 1 / Substrate Film / Layer 1 / Layer 2 / Layer 3 / Transparent Conductive Film

(g) Transparent Conductive Film / Layer 3 / Layer 2 / Hard Coating / Layer 1 / Substrate Film / Layer 1 / Hard Coating / Layer 2 / Layer 3 / Transparent Conductive Film

(h) Substrate film / layer 1 / layer 2 / layer 3 / SiO ₂ film / transparent conductive film

(i) 1st layer/substrate film/1st layer/2nd layer/3rd layer/SiO ₂ film/transparent conductive film

(j) Hard coat layer / 1st layer / base film / 1st layer / 2nd layer / 3rd layer / SiO ₂ film / transparent conductive film

(k) Hard coat layer / 1st layer / base film / 1st layer / hard coat layer / 2nd layer / 3rd layer / SiO ₂ film / transparent conductive film

(l) Transparent conductive film / SiO ₂ film / 3rd layer / 2nd layer / hard coat layer / 1st layer / base film / 1st layer / hard coat layer / 2nd layer / 3rd layer / SiO ₂ film /transparent conductive film

[Relationship of refractive index of each layer]

In the transparent conductive film of the present invention, the relationship of the refractive index of each layer is preferably such that the following relational expression 8 is satisfied. In this way, the see-through phenomenon of the transparent conductive film pattern can be further suppressed.

. Nt>n2≧nf>n1>n3.........(Equation 8)

In the formula, nt represents the refractive index of the transparent conductive film, n2 represents the refractive index of the second layer, nf represents the refractive index of the base film, n1 represents the refractive index of the first layer, and n3 represents the refractive index of the third layer.

[Visual reflectance]

In the transparent conductive film of the present invention, the difference in the visual reflectance between the pattern portion and the non-pattern portion of the transparent conductive film is preferably 3.0% or less, more preferably 2.5% or less, and particularly preferably 2.0% or less. The best is 1.5% or less.

[Color difference between the pattern portion and the non-pattern portion of the transparent conductive film]

The color difference ΔE of the reflection color of the pattern portion and the non-pattern portion of the transparent conductive film is preferably 7 or less, more preferably 6 or less, from the viewpoint of suppressing visual observation (perspective) of the transparent conductive film pattern. Very good for 5 or less. Here, ΔE is represented by the following relational expression 9.

. △ E = {(ΔL) ² + (Δa) ² + (Δb) ² } ^1/2 ... (Expression 9)

Where ΔL = (L ^* value in the non-pattern portion) - (L ^* value in the pattern portion)

Δa=(a ^* value in the non-pattern part)-(a ^* value in the pattern part)

Δb = (b ^* value in the non-pattern portion) - (b ^* value in the pattern portion).

According to the layer constitution of the present invention, the difference in the visual reflectance between the pattern portion and the non-pattern portion of the transparent conductive film can be lowered in a well-balanced manner as described above, and as a result, the see-through phenomenon can be sufficiently suppressed.

[Coloring of Transparent Conductive Film]

Coloring can be carried out by including at least one of the base film, the first layer, the second layer, and the third layer with a coloring dye or a coloring pigment. Thereby, the reflection color or the penetration color of the transparent conductive film can be adjusted.

Further, in the case where the hard coat layer is provided as described above, it may be colored by subjecting the hard coat layer to a coloring dye or a coloring pigment.

As described above, by adjusting the reflection color or the transmission color of the transparent conductive film of the present invention, the see-through phenomenon of the pattern of the transparent conductive film can be further suppressed.

[use]

The transparent conductive film of the present invention can be used for a transparent electrode, an antistatic film, or an electromagnetic wave shielding film used in a display such as a liquid crystal display or an electroluminescence display or a touch panel. The transparent conductive film of the present invention is particularly suitable for a touch panel, and is particularly suitable for an electrostatic capacitance type touch panel. Further, the transparent conductive film of the present invention can be used, for example, in an electrophoretic type, a torsion-ball type, a heat-sensitive rewritable type, a photo-storing liquid crystal type, a polymer-dispersed liquid crystal type, a host-guest type liquid crystal type, and a toner display type. A flexible display element such as a color changing type or an electric field deposition type.

[Examples]

The invention is further illustrated by the following examples, but the invention is not limited by the examples. Further, the measurement method and evaluation method in the present embodiment are as follows.

(1) Measurement of refractive index 1 (refractive index of the first layer, the second layer, the third layer, and the hard coat layer)

A coating film (dry thickness: about 2 μm) formed by coating each coating composition of the first layer, the second layer, the third layer, and the hard coat layer on a tantalum wafer by a spin coater at a temperature condition of 25 ° C Next, the refractive index at 633 nm was measured by a phase difference measuring apparatus (manufactured by Nikon Co., Ltd.: NPDM-1000).

(2) Measurement of refractive index 2 (refractive index of substrate film)

The refractive index of the base film (PET film) was measured in accordance with JIS K7105 (1981) using an Abbe refractometer.

(3) Measurement of refractive index 3 (refractive index of transparent conductive film and SiO ₂ film)

The transparent conductive film or the SiO ₂ film was laminated on a PET film having a known refractive index to a thickness of 30 nm under the same conditions as the actual build-up conditions, thereby preparing a sample for refractive index measurement. Next, the thickness of the transparent conductive film or the reflectance and thickness of the SiO ₂ film of the sample for refractive index measurement were measured. The refractive index of the transparent conductive film or the SiO ₂ film was calculated from the reflectance obtained in this manner, the film thickness, and the refractive index of the PET film.

Regarding the above-mentioned reflectance, the water-resistant sandpaper of #320 to 400 is uniformly scratched on the surface of the PET film opposite to the side on which the transparent conductive film or the SiO ₂ film is laminated, and then black paint (Black Magic Ink (registered trademark) liquid is applied. In the state where the reflection by the opposite side surface has completely disappeared, the reflectance at 550 nm was measured using a spectrophotometer UV-3150 of Shimadzu Corporation.

The thickness of the transparent conductive film or the SiO ₂ film is measured by the following method (4).

(4) Determination of the thickness of each layer and each film

An ultrathin section was cut out from the sample section, and a section of the sample was observed by a transmission electron microscope (Hitachi H-7100FA type) at an acceleration voltage of 100 kV and a magnification of 50,000 to 300,000 times, and each layer and each were measured. The thickness of the film. Further, in the case where the boundaries of the respective layers are not clear, the dyeing treatment may be performed as necessary.

(5) Visual identification of transparent conductive film patterns

The sample was placed on a black plate, and whether the pattern portion could be visually recognized was evaluated using the following criteria. In the case of a sample having a transparent conductive film in one of the area layers of the base film, the transparent conductive film was placed facing up for evaluation. In the case where the two-layer layer of the base film had a sample of a transparent conductive film, the transparent conductive films of the respective faces were placed upward and evaluated separately.

A: The graphic part cannot be visually recognized.

B: The pattern portion can be slightly visually recognized.

C: The pattern portion can be clearly identified by visual inspection.

<Coating composition of the first layer> (coating composition 1a of the first layer)

This composition is an aqueous dispersion containing 100 parts by mass of a naphthalene ring-containing polyester resin and a melamine-based crosslinking agent (hydroxymethyl type melamine-based crosslinking agent (NIKALAC, manufactured by Sanwa Chemical Co., Ltd.) MW12LF")) 5 parts by mass of colloidal cerium oxide ("SNOWTEX OL" manufactured by Nissan Chemical Industries, Ltd.) 1 part by mass. The coating composition had a refractive index of 1.58.

(coating composition 1b of the first layer)

This composition is an aqueous dispersion containing the following components: 100 parts by mass of an acrylic resin, and a melamine-based crosslinking agent (a methylol type melamine-based crosslinking agent ("NIKALAC MW12LF" manufactured by Sanwa Chemical Co., Ltd.)) 5 1 part by mass of a mass fraction of colloidal cerium oxide ("SNOWTEX OL" manufactured by Nissan Chemical Industries, Ltd.). The coating composition had a refractive index of 1.52.

<Coating composition of the second layer> (coating composition 2a of the second layer)

The coating composition is 37 parts by mass of an active energy ray-curable resin (10 parts by mass of dipentaerythritol hexaacrylate and 27 parts by mass of urethane acrylate), 60 parts by mass of zirconium oxide, and a photopolymerization initiator ( 3 parts by mass of "Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd. is obtained by dispersing or dissolving in an organic solvent. The coating composition had a refractive index of 1.70.

(coating composition 2b of the second layer)

The coating composition is 37 parts by mass of an active energy ray-curable resin (10 parts by mass of dipentaerythritol hexaacrylate and 27 parts by mass of urethane acrylate), 60 parts by mass of titanium oxide, and a photopolymerization initiator ( 3 parts by mass of "Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd. is obtained by dispersing or dissolving in an organic solvent. The coating composition had a refractive index of 1.75.

(coating composition 2c of the second layer)

The coating composition is 27 parts by mass of an active energy ray-curable resin (10 parts by mass of dipentaerythritol hexaacrylate and 17 parts by mass of urethane acrylate), 70 parts by mass of ruthenium pentoxide, and a photopolymerization initiator. (Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd.) is obtained by dispersing or dissolving 3 parts by mass of an organic solvent. The coating composition had a refractive index of 1.64.

(coating composition 2d of the second layer)

The coating composition is 77 parts by mass of an active energy ray-curable resin (20 parts by mass of dipentaerythritol hexaacrylate and 57 parts by mass of urethane acrylate), 20 parts by mass of ATO (tantalum tin oxide), and photopolymerization. 3 parts by mass of an initiator ("Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd.) was dispersed or dissolved in an organic solvent. The coating composition had a refractive index of 1.54.

<Coating composition of the third layer> (Layer 3 coating composition 3a)

The coating composition is an active energy ray-curable resin (containing dipentaerythritol hexaacrylate and urethane acrylate in a mass ratio of 1:3) of 47 parts by mass, hollow cerium oxide (50 parts by mass), and photopolymerization. 3 parts by mass of "Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd.) was dispersed or dissolved in an organic solvent. The coating composition had a refractive index of 1.35.

(Layer 3 coating composition 3b)

The coating composition is an active energy ray-curable resin containing dipentaerythritol hexaacrylate and urethane propylene at a mass ratio of 1:3. 57 parts by mass of the acid ester, 40 parts by mass of the hollow cerium oxide, and 3 parts by mass of a photopolymerization initiator ("Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd.) are dispersed or dissolved in an organic solvent. . The coating composition had a refractive index of 1.37.

(Layer 3 coating composition 3c)

This coating composition is an active energy ray-curable resin (containing dipentaerythritol hexaacrylate and urethane acrylate in a mass ratio of 1:3), 82 parts by mass of hollow cerium oxide, and 15 parts by mass of hollow cerium oxide, and photopolymerization. 3 parts by mass of "Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd.) was dispersed or dissolved in an organic solvent. The coating composition had a refractive index of 1.43.

(Layer 3 coating composition 3d)

The coating composition is bis-(α-fluoroacrylic acid)-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-ten Heptafluorodecyl glycol 100 parts by mass, poly(acrylic acid-3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-ten 10 parts by mass of hexafluoroanthryl group and 1 part by mass of a photopolymerization initiator ("Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd.) are dispersed or dissolved in an organic solvent. The coating composition had a refractive index of 1.36.

(Layer 3 coating composition 3e)

The coating composition is 82 parts by mass of an active energy ray-curable resin (20 parts by mass of dipentaerythritol hexaacrylate and 62 parts by mass of urethane acrylate), 15 parts by mass of ATO (antimony tin oxide), and photopolymerization. 3 parts by mass of an initiator ("Irgacure (registered trademark) 184" manufactured by Chiba Specialty Chemicals Co., Ltd.) was dispersed or dissolved in an organic solvent. The coating composition had a refractive index of 1.53.

(Layer 3 coating composition 3f)

The coating composition is 30 parts by mass of (meth)acrylic acid-β-(perfluorooctyl)ethyl ester, 3 parts by mass of pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, and light. 2 parts by mass of a polymerization initiator (2-methyl-1[4-(methylthio)phenyl]-2-morpholinepropan-1-one) is dispersed or dissolved in an organic solvent. The coating composition had a refractive index of 1.43.

[Example 1]

A transparent conductive film was produced in accordance with the following procedure. Further, after the first layer is laminated on both surfaces of the base film (PET film), an object in which the second layer, the third layer, and the transparent conductive film are provided on only one side of the base film (PET film) is produced. (Example 1a) and an object provided on both sides (Example 1b).

<Layer 1 layer>

In the film forming step of the PET film (series type), the coating composition 1a of the first layer was laminated on the polyethylene terephthalate having a refractive index of 1.65 and a thickness of 125 μm by a wet coating method (bar coating method). The both sides of the diester film (PET film) were dried to a thickness of 90 nm, and the first layer was laminated on the PET film.

<Layer 2 layer>

The coating composition 2a of the second layer is applied onto the first layer by a wet coating method (gravure coating method), and the thickness after curing is 40 nm, which is then dried and irradiated with ultraviolet rays to be cured. And the second layer is formed.

<Layer 3 layer>

The coating composition 3a of the third layer is applied onto the second layer by a wet coating method (gravure coating method) to have a thickness of 35 nm after hardening, and then dried and irradiated with ultraviolet rays to be cured. And the third layer is formed.

<Lamination of Transparent Conductive Film>

On the third layer, an ITO film as a transparent conductive film was deposited by sputtering to have a thickness of 30 nm.

<Charming of Transparent Conductive Film>

Only the pattern processing (etching treatment) of the transparent conductive film of the laminate obtained by the above-described method was subjected to pattern processing (etching treatment) to obtain a strip pattern, thereby obtaining a transparent conductive film.

[Examples 2 to 16 and Comparative Examples 1 to 6]

A transparent conductive film was produced in the same manner as in Example 1 except that the composition shown in Tables 1 and 2 was changed. In the same manner as in the first embodiment, the objects of the second layer, the third layer, and the transparent conductive film were provided on only one side of the base film (PET film), and the examples 2a to 16a and the comparative examples 1a to 6a were set. The two-sided objects were designated as Examples 2b to 16b and Comparative Examples 1b to 6b.

<evaluation>

The visibility of the transparent conductive film pattern was evaluated for each of the transparent conductive films produced by the above method. The results are disclosed in Tables 1 and 2. In addition, the object of the second layer, the third layer, and the transparent conductive film (Examples 1a to 16a, Comparative Examples 1a to 6a) and the object provided on both sides are provided only on one surface of the base film (PET film). Examples 1b to 16b and Comparative Examples 1b to 6b) have the same evaluation results, and therefore are collectively recorded.

From the results of Tables 1 to 4, it is apparent that the transparent conductive film pattern of the embodiment of the present invention cannot be visually recognized, and the transparent conductive film pattern of the comparative example can be visually recognized.

[Example 17]

A transparent conductive film was produced in accordance with the following procedure. Further, after the first layer was laminated on both sides of the base film (PET film), the second layer, the third layer, the SiO ₂ film, and the transparent conductive were formed only on one surface of the base film (PET film). The object (17a) of the film and the object (17b) provided on both sides.

<Layer 1 layer>

In the film forming step of the PET film (series type), the coating composition 1a of the first layer was laminated on the polyethylene terephthalate having a refractive index of 1.65 and a thickness of 125 μm by a wet coating method (bar coating method). The both sides of the diester film (PET film) were dried to a thickness of 90 nm, and the first layer was laminated on the PET film. The optical thickness of the first layer was 142 nm.

<Layer 2 layer>

The coating composition 2a of the second layer is applied onto the first layer by a wet coating method (gravure coating method), and then dried, and cured by irradiation with ultraviolet rays to have a thickness of 45 nm after hardening. And the second layer is formed. The optical thickness of the second layer was 77 nm.

<Layer 3 layer>

The coating composition 3d of the third layer is applied onto the second layer by a wet coating method (gravure coating method), and then dried, and cured by ultraviolet rays to have a thickness of 10 nm after hardening. Form the third layer. The optical thickness of the third layer was 14 nm.

<Lamination of SiO ₂ film>

A SiO ₂ film (refractive index of 1.46) having a thickness of 30 nm was laminated on the third layer by sputtering. The optical thickness of the SiO ₂ film was 44 nm.

<Lamination of Transparent Conductive Film>

An ITO film as a transparent conductive film was laminated on the above SiO ₂ film by sputtering to have a thickness of 30 nm.

<Charming of Transparent Conductive Film>

The transparent conductive film of the laminate obtained by the above-described method was subjected to pattern processing (etching treatment) in a strip shape to obtain a transparent conductive film.

<Evaluation of Example 17>

In the transparent conductive film of Example 17, the total thickness of the optical thickness of the second layer on one side of each of the base film, the optical thickness of the third layer, and the optical thickness of the SiO ₂ film was 135 nm. The visibility of the transparent conductive film pattern of any of the transparent conductive films (objects provided on only one side and objects provided on both sides) is "A".

[Embodiment 18]

In the first embodiment, the first layer, the second layer, the third layer, and the first layer and the second layer on the side of the transparent conductive film are provided on the PET film, and the opposite side A transparent conductive film was obtained in the same manner as in Example 1a except that the following hard coat layer was provided on one layer.

<layer of hard coating layer>

95 parts by mass of a photopolymerization initiator containing an active energy ray-curable resin (containing dipentaerythritol hexaacrylate and urethane acrylate in a mass ratio of 1:3) by a wet coating method (gravure coating method) (Irgacure (registered by Ciba Specialty Chemicals, Inc.) Trademark) 184") 5 parts by mass of the composition, which was then dried and irradiated with ultraviolet rays to be hardened to form a hard coat layer having a thickness of 2 μm (refractive index of 1.50).

[Embodiment 19]

In the embodiment 17a, the first layer and the second layer on the side of the first layer, the second layer, the third layer, the SiO ₂ film, and the transparent conductive film on which the PET film is provided, and the opposite thereof are provided. A transparent conductive film was obtained in the same manner as in Example 17a except that the same hard coat layer as in Example 18 was provided on the first layer of the side.

<Evaluation of Examples 18 and 19>

The visually recognizable pattern of the transparent conductive film pattern of the transparent conductive film of Example 18 was "A".

The visually recognizable pattern of the transparent conductive film pattern of the transparent conductive film of Example 19 was "A".

[Example 20]

In the same manner as in Example 17b, the transparent conductive layer was obtained in the same manner as in Example 17b except that the same hard coat layer as in Example 18 was provided between the first layer and the second layer provided on both surfaces of the PET film. film.

<Evaluation of Example 20>

The visually recognizable pattern of the transparent conductive film pattern of the transparent conductive film of Example 20 was "A".

Claims (18)

A transparent conductive film having a refractive index of 1.51 to 1.60 on one or both sides of a substrate film having a refractive index of 1.61 to 1.70 and an optical thickness of one side of each substrate film (1/4) a first layer of λ, a second layer having a refractive index of 1.61 to 1.80, a third layer having a refractive index of 1.50 or less, and a transparent conductive film having a refractive index of 1.81 or more, each of which is a single film. The total of the optical thickness of the second layer and the optical thickness of the third layer is in the range of 95 to 163 nm, the refractive index of the first layer (n1), the refractive index of the second layer (n2), and the first The relationship of the refractive index (n3) of the three layers satisfies n2>n1>n3, and a hard coat layer is provided between the first layer and the second layer, but λ is 380 to 780 nm. The transparent conductive film of claim 1, wherein the second layer has a refractive index of 1.65 to 1.78. The transparent conductive film of claim 1, wherein the first layer, the second layer, and the third layer each comprise a resin, and are all coated by a wet coating method. The transparent conductive film of the first aspect of the invention, wherein the second layer and the third layer are coated with an active energy ray-curable composition by a wet coating method and cured. The transparent conductive film of claim 1, wherein the second layer is coated with an active energy ray-curable composition containing an active energy ray-curable resin and a metal oxide by a wet coating method, and is hardened. And get the layer. Such as the transparent conductive film of claim 1 of the patent scope, wherein the third The layer is a layer obtained by coating and hardening an active energy ray-curable composition by a wet coating method, and the active energy ray-curable composition contains a fluorine-containing compound 30 with respect to 100% by mass of the composition. %the above. The transparent conductive film of claim 1, wherein the thickness (d2) of one surface of each of the base films of the second layer is 30 nm or more. The transparent conductive film according to claim 1, wherein the thickness (d3) of one surface of each of the base films of the third layer is 5 to 50 nm. The transparent conductive film of claim 1, wherein a total of an optical thickness of the second layer on one side of each of the base film and an optical thickness of the third layer is in the range of 95 to 150 nm. The transparent conductive film of claim 1, wherein the substrate film is a polyester film. The transparent conductive film of claim 1, wherein a refractive index (nf) of the base film, a refractive index (n1) of the first layer, a refractive index (n2) of the second layer, and the third The relationship between the refractive index (n3) of the layer and the refractive index (nt) of the transparent conductive film satisfies nt>n2≧nf>n1>n3. The transparent conductive film of the first aspect of the invention, wherein the hard coat layer is a layer obtained by applying a composition containing an active energy ray-curable resin by a wet coating method, and then hardening the hard coat layer. The refractive index of the coating ranges from 1.46 to 1.55. The transparent conductive film of claim 1, wherein the composition is the following (1) or (2): (1) hard coat layer / first layer / base film / first layer / hard coat / 2 layer/ 3rd layer / transparent conductive film (2) transparent conductive film / 3rd layer / 2nd layer / hard coat layer / 1st layer / base film / 1st layer / hard coat layer / 2nd layer / 3rd layer / Transparent conductive film. The transparent conductive film of claim 1, wherein a relationship between a refractive index (nf) of the base film, a refractive index (n1) of the first layer, and a refractive index (nh) of the hard coat layer satisfies nf >n1>nh, and the refractive index difference (nf-n1) between the base film and the first layer and the refractive index difference (n1-nh) between the first layer and the hard coat layer are each 0.1 or less. The transparent conductive film of claim 1, wherein an SiO ₂ film is provided between the third layer and the transparent conductive film. The transparent conductive film of claim 15, wherein the total thickness of the second layer on one side of each of the substrate films, the optical thickness of the third layer, and the optical thickness of the SiO ₂ film are (1) /4) λ, however, λ is 380 to 780 nm. A touch panel comprising the transparent conductive film of the first aspect of the patent application. The touch panel of claim 17, wherein the touch panel is a capacitive touch panel.