JP2018085297A - Transparent conductive film, manufacturing method thereof and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film having excellent moisture and thermal resistance, a manufacturing method thereof and a touch panel equipped with the transparent conductive film.SOLUTION: A transparent conductive film includes a base material film, an optical regulation layer being a coating film, and a transparent conductive layer, in this order. When a reflection spectrum is measured before/after immersing a laminate after the transparent conductive layer is removed in an aqueous sodium hydroxide of 7 wt.% at 50°C for 8 minutes, an absolute value of a difference is 50 nm or less with regard to a wavelength λ0[nm] at which a reflective index is lowest before the immersion and a wavelength λ1[nm] at which a reflective index is lowest after the immersion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transparent conductive film, a manufacturing method thereof, and a touch panel.

  In recent years, a projected capacitive touch panel and a matrix resistive touch panel are capable of multi-point input (multi-touch), and thus have excellent operability, and their demand is rapidly increasing. As an electrode member of such a touch panel, a transparent conductive film in which a transparent conductive thin film is formed on a transparent film group has been proposed.

  In the touch panel as described above, a transparent conductive film having a patterned transparent conductive layer is used. Although indium-tin composite oxide (ITO) is widely used as a material for the transparent conductive layer from the viewpoint of visible light transmittance, its refractive index is high, so when the transparent conductive layer containing ITO is patterned. Has a difference in pattern visibility between the part where the transparent conductive layer forms the pattern (pattern forming part) and the part where the transparent conductive layer is removed (pattern opening), and the pattern is observed from the outside, and the appearance deteriorates. Or color may occur. In order to make such a pattern inconspicuous, the technique which provided the optical adjustment layer between the base film and the transparent conductive layer is proposed (for example, patent documents 1-3).

Patent No. 4,364,938 Japanese Patent No. 4874145 JP 2011-134482 A

  By the way, for touch panel applications mounted on smart phones and car navigation systems that are placed under high temperature and high humidity, operation is hindered even under harsher conditions such as 85 ° C. and 85% RH. There is a strong demand for high wet heat durability that does not come out. However, when the transparent conductive film according to the above technology is subjected to a heat and humidity resistance test at 85 ° C. and 85% RH, cracks are generated in the patterned transparent conductive film, and it is newly found that the electrical characteristics are deteriorated. ing.

  An object of this invention is to provide the touchscreen provided with the transparent conductive film which has the outstanding heat-and-moisture resistance, its manufacturing method, and the said transparent conductive film.

  As a result of intensive studies to solve the above problems, the inventors of the present application have found that when a transparent conductive film patterned with a transparent conductive film is placed in a high-temperature and high-humidity environment, an optical adjustment formed by a coating process. It was found that the layer caused cohesive failure and voids were generated there, and the transparent conductive layer could not follow the expansion of the voids and cracks in the transparent conductive layer were generated. The inventors of the present application have further studied and found that the object can be achieved by adopting the following configuration, and have completed the present invention.

In one embodiment, the present invention comprises a base film, an optical adjustment layer that is a coating film, and a transparent conductive layer in this order,
When the reflection spectrum before and after immersing the laminate after removing the transparent conductive layer in a 7% by weight aqueous sodium hydroxide solution at 50 ° C. for 8 minutes was measured, the wavelength λ 0 [ nm] and a transparent conductive film in which the absolute value of the difference between the wavelength λ1 [nm] at which the reflectance is minimum after immersion is 50 nm or less.

  The inventors of the present application speculated that the cohesive failure of the optical adjustment layer in a high-temperature and high-humidity environment was caused by insufficient curing of the coating film, and examined various processes for forming the optical adjustment layer. Among them, in the sample with good results in the alkali resistance test, the occurrence frequency of cracks in the transparent conductive layer was reduced, and it was found that there was a correlation between the alkali resistance test and the frequency of occurrence of cracks. . In the alkali resistance test, structural and characteristic changes before and after immersion of the sample in an alkaline solution are evaluated, and the strength (degree of curing) of the cured film (optical adjustment layer) obtained by curing the coating film is also strong. Since it has a correlation, further investigation was made on using the alkali resistance test as an index of the degree of cure of the optical adjustment layer. If the structure of the optical adjustment layer changes before and after immersion in the alkaline solution, the optical characteristics are also expected to change. Based on this idea, we measured the reflection spectrum of the sample before and after immersion and evaluated the change in the spectrum shape when comparing the two. When the spectrum change was small, the frequency of cracks in the transparent conductive layer decreased. Turned out to be.

  In the transparent conductive film, the absolute value (that is, | λ0−λ1 |) of the difference between the wavelengths (hereinafter also referred to as “minimum reflectance wavelength”) having the lowest reflectance in the reflection spectrum before and after the alkali immersion. Hereinafter, for convenience, it is also expressed as “Δλ”.) Is 50 nm or less, so that the structural change of the optical adjustment layer with respect to alkali immersion is small, in other words, the optical adjustment layer has a sufficient degree of curing. Thereby, even when the transparent conductive film is placed in a high-temperature and high-humidity environment, the cohesive failure of the optical adjustment layer is suppressed, and as a result, cracks in the transparent conductive layer can be prevented. When Δλ exceeds 50 nm, the structural change of the optical adjustment layer before and after immersion in alkali is too large to cause cohesive failure, which may lead to cracks in the transparent conductive layer when placed in a high temperature and high humidity environment.

  In one embodiment, the optical adjustment layer is formed of an organic-inorganic composite material including an organic component and an inorganic component, and a median diameter value of the inorganic component is preferably smaller than a thickness value of the optical adjustment layer. . By adding an inorganic component, the film strength of the optical adjustment layer can be further improved, and the heat and moisture resistance can be further improved. Moreover, adjustment of optical characteristics becomes easy by blending the inorganic component, and the reflectance of the transparent conductive film can be further reduced. Furthermore, by making the median diameter value of the inorganic component smaller than the thickness value of the optical adjustment layer, it is possible to suppress surface unevenness due to the inorganic component and suppress light scattering.

  In one embodiment, it is preferable that a hard coat layer is formed between at least one of the base film and the optical adjustment layer, and at least one side of the base film opposite to the optical adjustment layer. . By forming the hard coat layer, it is possible to impart strength to the base film, and it is possible to improve the handling properties in the production process and transport process of the transparent conductive film.

  In one Embodiment, it is preferable that the said base film contains cycloolefin type resin. Thereby, the transparency of the said transparent conductive film can be improved more, and a favorable appearance can be achieved.

In one embodiment, the present invention is a process of forming a coating film by applying a coating liquid for forming an optical adjustment layer on a base film,
A step of curing the coating film by energy ray irradiation to form an optical adjustment layer; and a step of forming a transparent conductive layer on the optical adjustment layer,
The energy beam irradiation is performed while running the base film,
The present invention relates to a method for producing a transparent conductive film, in which the traveling speed v [m / min] of the base film and the integrated light amount L [mJ / cm ² ] of the energy ray satisfy the following relationship.
v <0.1L

  In the manufacturing method, when forming the optical adjustment layer by curing the coating film with energy rays, the value of the traveling speed of the film is reduced to a value of 10% or less with respect to the value of the integrated light amount of the energy rays. . If the integrated light quantity is constant, the irradiation intensity from the light source becomes weaker by slowing the traveling speed of the film, but the irradiation time of the energy beam to the coating film can be made longer. In addition, when oxygen is present at the time of energy beam irradiation, the curing reaction in the coating film is hindered. Therefore, an inert gas is often introduced during the irradiation to eliminate oxygen. If the running speed of the film is too high, the atmosphere replacement with the inert gas becomes insufficient, whereas in the manufacturing method, the running speed of the film is greatly reduced, so that the atmosphere replacement with the inert gas is sufficiently performed. As a result, the oxygen concentration in the energy beam irradiation atmosphere can be sufficiently reduced. As described above, by reducing the traveling speed of the film during energy beam irradiation to a predetermined range, both the irradiation time of the energy beam and the inert gas replacement can be achieved at a high level, sufficiently A cured optical adjustment layer can be formed.

  In one Embodiment, it is preferable that the oxygen concentration of the said coating film vicinity in the case of the said energy ray irradiation is less than 100 ppm. Thereby, the hardening reaction of the coating film by irradiation of energy rays can be promoted, and an optical adjustment layer having a sufficient degree of hardening can be formed.

  In one embodiment, the present invention relates to a touch panel including the transparent conductive film. The transparent conductive film is suitable for touch panel applications that are placed under high temperature and high humidity such as smartphones and car navigation systems.

It is typical sectional drawing of the transparent conductive film which concerns on one Embodiment of this invention. In FIG. 2, the reflection spectrum before and behind alkali immersion of Example 4 is shown.

  An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the form shown in the drawings is not an actual size ratio, and there is a part that is partially enlarged or reduced for convenience of explanation. In addition, the terms indicating the positional relationship such as top / bottom / left / right and front / back in this specification are merely terms for facilitating the description, and there is no intention to specify the positional relationship of the actual specific configuration.

<Transparent conductive film>
FIG. 1 is a cross-sectional view schematically showing one embodiment of the transparent conductive film of the present invention. In the transparent conductive film 10, the optical adjustment layer 3 and the transparent conductive layer 4 are formed in this order on one surface of the base film 1. In the present embodiment, as shown in FIG. 1, a hard coat layer 2 may be provided between the base film 1 and the optical adjustment layer 3. In FIG. 1, the hard coat layer is formed on one side of the base film 1, but may be formed on both sides of the base film 1.

<Base film>
The base film 1 is not particularly limited, but various plastic films having transparency are used. For example, the materials include polyester resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, polynorbornene resins, and other polycycloolefin resins (meta ) Acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins and the like. Among these, a cycloolefin resin, a polyester resin, a polycarbonate resin, and a polyolefin resin are preferable, and a cycloolefin resin is particularly preferable.

  The cycloolefin resin is not particularly limited as long as it is a resin having a monomer unit composed of a cyclic olefin (cycloolefin). The cycloolefin resin used for the cycloolefin resin film may be either a cycloolefin polymer (COP) or a cycloolefin copolymer (COC). The cycloolefin copolymer refers to an amorphous cyclic olefin resin that is a copolymer of a cyclic olefin and an olefin such as ethylene.

  As the cyclic olefin, there are a polycyclic cyclic olefin and a monocyclic cyclic olefin. Such polycyclic olefins include norbornene, methylnorbornene, dimethylnorbornene, ethylnorbornene, ethylidenenorbornene, butylnorbornene, dicyclopentadiene, dihydrodicyclopentadiene, methyldicyclopentadiene, dimethyldicyclopentadiene, tetracyclododecene. , Methyltetracyclododecene, dimethylcyclotetradodecene, tricyclopentadiene, tetracyclopentadiene, and the like. Examples of monocyclic olefins include cyclobutene, cyclopentene, cyclooctene, cyclooctadiene, cyclooctatriene, and cyclododecatriene.

  The optical film made of the cycloolefin-based resin is also available as a commercial product, for example, Topas made by Polyplastics, Arton made by JSR, ZEONOR made by Nippon Zeon, ZEONEX, Appel made by Mitsui Chemicals, etc. Is mentioned.

  The polycarbonate resin is not particularly limited, and examples thereof include aliphatic polycarbonate, aromatic polycarbonate, and aliphatic-aromatic polycarbonate. Specifically, for example, as polycarbonate (PC) using bisphenols, bisphenol A polycarbonate, branched bisphenol A polycarbonate, foamed polycarbonate, copolycarbonate, block copolycarbonate, polyester carbonate, polyphosphonate carbonate, diethylene glycol bisallyl carbonate (CR- 39). Polycarbonate-based resins also include those blended with other components such as bisphenol A polycarbonate blends, polyester blends, ABS blends, polyolefin blends, styrene-maleic anhydride copolymer blends. Examples of commercially available polycarbonate resin include “OPCON” manufactured by Ewa Co., Ltd., “Panlite” manufactured by Teijin Limited, and “Iupilon (UV absorber-containing polycarbonate)” manufactured by Mitsubishi Gas Chemical.

  The thickness of the base film 1 is preferably in the range of 2 to 200 μm, and more preferably in the range of 20 to 180 μm. When the thickness of the base film 1 is less than 2 μm, the mechanical strength of the base film 1 is insufficient, and the operation of continuously forming the optical adjustment layer 3 and the transparent conductive layer 4 by making the film base into a roll shape. It can be difficult. On the other hand, if the thickness exceeds 200 μm, the scratch resistance of the transparent conductive layer 4 and the dot characteristics for a touch panel may not be improved.

  The base film 1 is preliminarily subjected to etching treatment such as sputtering, plasma treatment, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, and undercoating treatment on the surface to form a hard film formed on the film substrate. You may make it improve adhesiveness with a coating layer, an optical adjustment layer, etc. In addition, before forming the hard coat layer and the optical adjustment layer, the surface of the film base material may be removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like, if necessary.

<Hard coat layer>
In the transparent conductive film 10, the hard coat layer 2 can be provided between the base film 1 and the optical adjustment layer 3. By providing the hard coat layer 2, it is possible to improve the scratch resistance and the handling property of the flexible base film 1 such as a cycloolefin resin film.

(Resin composition)
The hard coat layer is a cured product layer of the resin composition. As the resin composition, a resin composition having sufficient strength as a film after the formation of the hard coat layer and having transparency can be used without particular limitation. In particular, the resin composition has three or more polymerizable functional groups in the molecule, the component A having a weight average molecular weight of 200 to 1,000, and the number of polymerizable functional groups per unit molecular weight in the molecule. It is preferable to contain the component B which is less than A and whose weight average molecular weight is more than 1000 and not more than 100,000. In the hard coat layer, a structure derived from component A having a weight average molecular weight of 200 or more and 1,000 or less contributes to scratch resistance by acting as a hard segment, and at the same time, a component having a weight average molecular weight of more than 1000 and less than 100,000 Since the structure derived from B acts as a soft segment, it can contribute to crack resistance.

  From the viewpoint of increasing the hardness and preventing the film from being scratched, the amount of the solid content of Component A may be increased. On the other hand, from the viewpoint of imparting flexibility and preventing film breakage, the solid content of component B is preferably greater than the solid content of component A. In this case, the amount of the solid content of Component B is preferably 70% by weight to 90% by weight, and 75% by weight to 85% by weight with respect to the total amount of the solid content of Component A and the solid content of Component B. More preferably.

  Examples of the resin used in the resin composition include a thermosetting resin, a thermoplastic resin, an ultraviolet curable resin, an electron beam curable resin, and a two-component mixed resin. Among these, a curing treatment by ultraviolet irradiation is performed. Therefore, an ultraviolet curable resin capable of efficiently forming each hard coat layer by a simple processing operation is preferable.

  Examples of the ultraviolet curable resin include polyester-based, acrylic-based, urethane-based, amide-based, silicone-based, and epoxy-based resins, and include ultraviolet curable monomers, oligomers, polymers, and the like. The ultraviolet curable resin preferably used is, for example, one having an ultraviolet polymerizable functional group such as an acryloyl group, and in particular, an acrylic monomer or oligomer having 2 or more, particularly 2 to 6 such polymerizable functional groups in the molecule. And those containing a component at the level and a component at the polymer level as the component A and the component B. Further, an ultraviolet polymerization initiator is blended in the ultraviolet curable resin. Such a polyfunctional high molecular weight component and a polyfunctional low molecular weight component form a three-dimensional crosslinked structure after the resin composition is cured, and the polyfunctional low molecular weight component mainly serves as a starting point for crosslinking of the crosslinked structure. The polyfunctional high molecular weight component having a smaller number of polymerizable functional groups per unit molecular weight contributes mainly to flexibility as a soft segment.

  In the present embodiment, urethane (meth) acrylate can be suitably used as the ultraviolet curable resin.

  As said urethane (meth) acrylate, what contains (meth) acrylic acid, (meth) acrylic acid ester, a polyol, and diisocyanate as a structural component is used. For example, by using at least one monomer of (meth) acrylic acid and (meth) acrylic acid ester and a polyol, a hydroxy (meth) acrylate having one or more hydroxyl groups is prepared, and this is reacted with diisocyanate. Urethane (meth) acrylate can be produced. Urethane (meth) acrylate may be used individually by 1 type, and may use 2 or more types together.

  Examples of (meth) acrylic acid esters include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, and butyl (meth) acrylate; cyclohexane such as cyclohexyl (meth) acrylate and the like. Examples include alkyl (meth) acrylate.

  The polyol is a compound having at least two hydroxyl groups. For example, ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, , 4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5- Pentanediol, hydroxypivalic acid neopentyl glycol ester, tricyclodecane dimethylol, 1,4-cyclohexanediol, spiroglycol, tricyclodecane dimethylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, propylene oxide Added bisphenol A, trimethylolethane, trimethylolpropane, glycerin, 3-methylpentane-1,3,5-triol, pentaerythritol, dipentaerythritol, tripentaerythritol, glucose, polypropylene glycol, polybutylene glycol, 1 , 2-butylene oxide and ethylene oxide copolymer and propylene oxide and ethylene oxide copolymer at least one diol, aliphatic or cyclic polyether polyol, polyester polyol, polycarbonate polyol, poly Examples include caprolactone polyol.

  As the diisocyanate, for example, various aromatic, aliphatic or alicyclic diisocyanates can be used. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4, 4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4,4-diphenyl diisocyanate, xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-diphenylmethane diisocyanate, and hydrogenated products thereof. Can be mentioned.

  The mixing ratio of urethane (meth) acrylate in the resin composition is not particularly limited. From the viewpoint of flexibility and hardness of the hard coat layer, adhesion to the base film, etc., the blending ratio of urethane (meth) acrylate is, for example, in the range of 10 to 90% by weight with respect to the total weight of the resin composition. Preferably, it is in the range of 20 to 80% by weight.

  In addition to the above components, the curable resin used in the resin composition forming the hard coat layer may have a reactive diluent. Reactive diluents include 1,6-hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexanediol (meth) acrylate, and pentaerythritol, which have a relatively low viscosity. Bi- or higher functional monomers and oligomers such as tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, neopentyl glycol di (meth) acrylate, and monofunctional monomers such as N-vinyl Acrylic esters such as pyrrolidone, ethyl acrylate, propyl acrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl Methacrylic acid esters such as tacrylate, isooctyl methacrylate, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, nonylphenyl methacrylate, tetrahydrofurfuryl methacrylate, derivatives thereof such as caprolactone modifications thereof, styrene, q-methylstyrene, acrylic acid, etc., or A mixture thereof can be used.

  In addition to the materials described above, conventional additives such as plasticizers, surfactants, antioxidants, UV absorbers, leveling agents, thixotropic agents, antistatic agents, photopolymerization initiators, and the like should be used for the resin composition. Can do. The use of a thixotropic agent is advantageous for the formation of protruding particles on the surface of fine irregularities when the hard coat layer contains particles. Examples of the thixotropic agent include silica and mica of 0.1 μm or less. The content of these additives is usually about 15 parts by weight or less, preferably 0.01 to 15 parts by weight with respect to 100 parts by weight of the ultraviolet curable resin.

(particle)
Each hard coat layer may contain particles. From the viewpoint of increasing hardness and imparting blocking resistance, it is preferable to contain particles.

  As said particle | grains, what has transparency, such as various metal oxides, glass, a plastics, can be especially used without a restriction | limiting. For example, inorganic particles such as silicon oxide (silica) particles, hollow nanosilica particles, titanium oxide particles, aluminum oxide particles, zinc oxide particles, tin oxide particles, zirconium oxide particles, calcium oxide particles, polymethyl methacrylate, polystyrene, polyurethane, Examples thereof include crosslinked or uncrosslinked organic particles and silicone particles composed of various polymers such as acrylic resin, acrylic-styrene copolymer, benzoguanamine, melamine, and polycarbonate. One or two or more kinds of the particles can be appropriately selected and used, but inorganic particles and organic particles are preferable from the viewpoint of refractive index.

(Coating composition)
The coating composition used to form the hard coat layer includes the resin, particles, and solvent described above.

  The coating composition can be prepared by mixing the above resin and particles with a solvent, an additive, a catalyst and the like as necessary. The solvent in the coating composition is not particularly limited, and is appropriately selected in consideration of the resin to be used, the material used as the base of the coating, the coating method of the composition, and the like. Specific examples of the solvent include aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone; diethyl ether, isopropyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and ethylene glycol. Ether solvents such as diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, anisole, phenetol; ester solvents such as ethyl acetate, butyl acetate, isopropyl acetate, ethylene glycol diacetate; dimethylformamide, diethylformamide, N -Amide solvents such as methylpyrrolidone; methyl cellosolve, ethyl Cellosolve, cellosolve-based solvents such as butyl cellosolve; methanol, ethanol, alcohol solvents such as propanol; and the like; dichloromethane, halogenated solvents such as chloroform. These solvents may be used alone or in combination of two or more. Of these solvents, ester solvents, ether solvents, alcohol solvents and ketone solvents are preferably used.

  In the coating composition, the particles are preferably dispersed in a solution. As a method for dispersing particles in a solution, various known methods such as a method of adding particles to a resin composition solution and mixing, a method of adding particles dispersed in a solvent in advance to a resin composition solution, and the like. Can be adopted.

  The solid concentration of the coating composition is preferably 1% by weight to 70% by weight, more preferably 2% by weight to 50% by weight, and most preferably 5% by weight to 40% by weight. If the solid content concentration is too low, the unevenness of the bulge on the surface of the hard coat layer becomes large in the drying step after coating, and haze may increase. On the other hand, if the solid content concentration is too high, the contained components are likely to aggregate, and as a result, the aggregated portion becomes obvious and the appearance of the transparent conductive film may be impaired.

(Coating and curing)
The hard coat layer 2 can be formed by applying the coating composition on the base film 1. In addition, a coating composition may be performed directly on the base film 1, and can also be performed on the undercoat layer etc. which were formed on the base film 1.

  The hard coat layer is applied by applying the coating composition on the base film, and if the coating composition contains a solvent, the solvent is dried and cured by application of heat, active energy rays, or both. Can be obtained. For the heat, known means such as an air circulation oven or an IR heater can be used, but it is not limited to these methods. Examples of active energy rays include, but are not limited to, ultraviolet rays, electron beams, and gamma rays.

  The application method of the coating composition can be selected in a timely manner according to the coating composition and the state of the painting process. For example, dip coating method, air knife coating method, curtain coating method, roller coating method, wire bar coating method, gravure method It can be applied by a coating method, a die coating method or an extrusion coating method.

A hard coat layer can be formed by curing the coating film after applying the coating composition. When the resin composition is photocurable, it can be cured by irradiating light using a light source that emits light having a wavelength as required. As light to irradiate, for example, light having an exposure amount of 150 mJ / cm ² or more, preferably 150 mJ / cm ^{2 to} 1000 mJ / cm ² can be used. The wavelength of the irradiation light is not particularly limited, and for example, irradiation light having a wavelength of 380 nm or less can be used. In addition, you may heat in the case of a photocuring process.

  The hard coat layer 2 is optically formed on the hard coat layer by subjecting the surface to an etching treatment or undercoating treatment such as sputtering, plasma treatment, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, and oxidation in advance. You may make it improve adhesiveness with an adjustment layer etc. In addition, before forming the optical adjustment layer, the surface of the hard coat layer may be removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like, if necessary.

<Optical adjustment layer>
In the transparent conductive film 10, an optical adjustment layer 3, which is a coating film, is provided between the hard coat layer 2 and the transparent conductive layer 4 for the purpose of controlling adhesion and reflection characteristics of the transparent conductive layer. Yes. Moreover, the optical adjustment layer reduces the difference in reflectance between the two by adjusting the optical thickness difference between the pattern forming portion where the transparent conductive layer is formed and the pattern opening where the transparent conductive layer is removed, It can be provided for the purpose of making the pattern difficult to be visually recognized. The layer structure of the optical adjustment layer 3 is not limited to a one-layer structure, and may be two layers or may have a layer structure of three or more layers. When two or more optical adjustment layers are formed, at least one layer may be a coating film, and the remaining layers may be a sputtered film formed by a dry method (for example, sputtering).

  When the optical adjustment layer has a two-layer structure, the two optical adjustment layers preferably have different refractive indexes. From the viewpoint of reducing the reflectance by controlling the reflection characteristics at a higher level, the refractive index of the optical adjustment layer close to the base film 1 is preferably higher than the refractive index of the optical adjustment layer far from the base film 1. In this case, the refractive index of the optical adjustment layer close to the base film is preferably 1.60 or more and 1.90 or less, and more preferably 1.70 or more and 1.80 or less. The refractive index of the optical adjustment layer far from the base film is preferably 1.35 or more and 1.60 or less, and more preferably 1.45 or more and 1.55 or less.

  The thickness of the optical adjustment layer (in the case of a plurality of layers, the thickness of each layer) is preferably 10 nm to 200 nm, more preferably 20 nm to 150 nm, and still more preferably 20 nm to 130 nm. If the thickness of the optical adjustment layer is too small, it is difficult to form a continuous film. On the other hand, when the thickness of the optical adjustment layer is excessively large, the transparency of the transparent conductive film tends to decrease, or cracks tend to occur in the optical adjustment layer.

  The optical adjustment layer may be formed of any of an organic component, an inorganic component, and an organic-inorganic composite material including an organic component and an inorganic component. Among these, at least one optical adjustment layer is preferably formed of an organic-inorganic composite material containing an organic component and an inorganic component. By using the inorganic component in combination with the organic component, the film strength of the optical adjustment layer can be further improved, and the heat and moisture resistance can be further improved. Moreover, the addition of the inorganic component facilitates the adjustment of the optical characteristics of the optical adjustment layer, and the reflectance of the transparent conductive film can be further reduced.

(Organic component)
It does not specifically limit as an organic component, An ultraviolet curable resin, a thermosetting resin, a thermoplastic resin etc. are used. From the viewpoint of suppressing the processing speed and thermal damage to the base film 1, it is particularly preferable to use an ultraviolet curable resin.

  As such an ultraviolet curable resin, for example, a curable compound having at least one of an acrylate group and a methacrylate group that is cured by light (ultraviolet rays) can be used. Examples of the curable compound include acrylates and methacrylates of polyfunctional compounds such as silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols. Oligomers or prepolymers. These may be used alone or in combination of two or more.

  In addition to the above components, the ultraviolet curable resin used for the organic component of the organic-inorganic composite material may have a reactive diluent. As the reactive diluent, for example, a reactive diluent having at least one of an acrylate group and a methacrylate group can be used. As a specific example of the reactive diluent, for example, a reactive diluent described in JP-A-2008-88309 can be used, and includes a monofunctional acrylate, a monofunctional methacrylate, a polyfunctional acrylate, a polyfunctional methacrylate, and the like. As the reactive diluent, trifunctional or higher acrylate and trifunctional or higher methacrylate are preferable. This is because the hardness of the hard coat layer can be made excellent. Examples of other reactive diluents include butanediol glycerin ether diacrylate, isocyanuric acid acrylate, isocyanuric acid methacrylate, and the like. These may be used alone or in combination of two or more.

(Inorganic component)
The organic-inorganic composite material contains an inorganic component in addition to an organic component such as an ionizing radiation curable resin. Examples of the inorganic component include fine particles or fine powders of inorganic oxides such as silicon oxide (silica), titanium oxide, aluminum oxide, zinc oxide, tin oxide, and zirconium oxide. Among these, from the viewpoint of controlling the refractive index of the hard coat layer, fine particles of silicon oxide (silica), titanium oxide, aluminum oxide, zinc oxide, tin oxide, and zirconium oxide are preferable, and silicon oxide is particularly preferable. These may be used alone or in combination of two or more.

  The median diameter value of the inorganic component is preferably smaller than the thickness value of the optical adjustment layer. When the optical adjustment layer is formed of an organic-inorganic composite material, a projection-like appearance defect having a relatively small size may occur. This is considered to be caused by the surface irregularities of the optical adjustment layer formed by the inorganic component. Therefore, it is preferable that the median diameter value of the inorganic component is made smaller than the thickness value of the optical adjustment layer, and the surface unevenness caused by the inorganic component is suppressed to suppress light scattering.

  The specific median diameter of the inorganic component is preferably 50 nm or less, more preferably 40 nm or less, and even more preferably 30 nm or less. Thus, if the mode particle diameter of the nanoparticles is small, it is difficult to cause visible light scattering as described above, and the refractive index of the organic component and the nanoparticles in the organic-inorganic composite material is different. The haze of the optical adjustment layer is suppressed from significantly increasing. In addition, although the minimum of the median diameter of an inorganic component is so preferable that it is small, it is preferable that it is 5 nm or more from a viewpoint of preventing aggregation and making dispersibility favorable.

  In this specification, the “median diameter” means a particle diameter (d50) in which the cumulative frequency of particle distribution is 50%, and the median diameter of the inorganic component is up to a solid content concentration of 1% with a diluent. It is obtained by diluting and measuring the particle size distribution with a dynamic light scattering particle size distribution measuring device (“LB-500” manufactured by Horiba, Ltd.). The diluent is appropriately selected depending on the type of inorganic component and the type of surface modification of the inorganic component.

  The inorganic oxide nanoparticles are preferably surface-modified with an organic compound containing a polymerizable unsaturated group. This unsaturated group reacts and cures with the organic component in the organic-inorganic composite material, whereby the hardness of the hard coat layer can be improved. Examples of the polymerizable unsaturated group in the organic compound for surface modification of the inorganic oxide nanoparticles include (meth) acryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, cinnamoyl group, maleate group, Acrylamide groups are preferred. The organic compound containing a polymerizable unsaturated group may be a compound having a silanol group in the molecule or a compound that generates a silanol group by hydrolysis. Moreover, it is also preferable that the organic compound containing a polymerizable unsaturated group has a photosensitive group.

  The blending amount of the inorganic oxide nanoparticles in the organic-inorganic composite material is preferably in the range of 50 to 300 parts by weight with respect to 100 parts by weight of the organic component solids such as ionizing radiation curable resin, More preferably, it is in the range of parts to 200 parts by weight. By making the blending amount of the inorganic oxide nanoparticles in the organic-inorganic composite material within the above range, it is possible to prevent light scattering by suppressing the casting of the coating liquid for forming the optical adjustment layer around the raised portion. it can. For example, the refractive index of the optical adjustment layer can be adjusted.

(Additive)
Various additives may be further added to the material for forming the optical adjustment layer 3. Examples of additives include a polymerization initiator for curing an organic-inorganic composite material to form an optical adjustment layer, a leveling agent, a pigment, a filler, a dispersant, a plasticizer, an ultraviolet absorber, a surfactant, an oxidation agent. An inhibitor, a thixotropic agent, etc. can be used.

  A conventionally well-known photoinitiator can be used as a polymerization initiator. For example, 2,2-dimethoxy-2-phenylacetophenone, acetophenone, benzophenone, xanthone, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, benzoin propyl ether, benzyldimethyl ketal, N, N, N, N-tetramethyl-4,4′-diaminobenzophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, and other thioxanthate compounds can be used.

  As the leveling agent, a fluorine-based or silicone-based leveling agent can be used as appropriate, and a silicone-based leveling agent is more preferable. Examples of the silicone leveling agent include polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polymethylalkylsiloxane. The addition amount of the fluorine-based or silicone-based leveling agent may be added within a range of 0.01 to 5 parts by weight with respect to a total of 100 parts by weight of the solid content of the organic component and the inorganic component in the organic-inorganic composite material. preferable.

  The transparent conductive film 10 includes a base film 1, an optical adjustment layer 3 that is a coating film, and a transparent conductive layer 4 in this order, and a laminate (base film 1) after removing the transparent conductive layer 4. When the reflection spectrum before and after immersing the coating film 2) in a 7 wt% sodium hydroxide aqueous solution at 50 ° C. for 8 minutes was measured, the wavelength λ 0 [nm] at which the reflectance becomes the lowest before the immersion and after the immersion The absolute value of the difference from the wavelength λ1 [nm] at which the reflectance is lowest is 50 nm or less. Δλ (| λ0−λ1 |) may be 50 nm or less, preferably 25 nm or less, and more preferably 10 nm or less. Δλ is preferably 0 nm, but may be 2 nm or more. By reducing Δλ, the optical adjustment layer has a sufficient degree of curing so as not to exhibit a structural change with respect to alkali immersion. Thereby, even when the transparent conductive film is placed in a high-temperature and high-humidity environment, cohesive failure of the optical adjustment layer is suppressed, and as a result, cracks in the transparent conductive layer can be prevented.

(Transparent conductive layer)
The transparent conductive layer can be provided on the first cured resin layer provided on one surface side of the transparent resin film. Moreover, a transparent conductive layer can also be provided through an optical adjustment layer. The transparent conductive layer is formed with at least one transparent conductive layer, and may have two or more transparent conductive layers. The transparent conductive layer is a thin film mainly composed of a metal conductive oxide or a thin film mainly composed of a composite metal oxide containing a main metal and one or more impurity metals. These conductive thin films are not particularly limited as long as they are transparent and have conductivity. Sc, Y, Si, Zr, Hf, V, Nb, Ta, Cr, Mo, W , Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Mg, Ga, Ti, Ge, In, Sn, Pb , As, Sb, Bi, Se, Te, and I, a metal oxide mainly containing one kind of metal selected from the group consisting of is preferably used. From the viewpoint of the transparency and conductivity of the transparent conductive layer, the main metal element is preferably any of In, Zn, and Sn, and most preferably an indium composite oxide. When the transparent conductive layer is a composite metal oxide containing a main metal and an impurity metal, one or more metals selected from the above group are preferably used as the impurity metal.

  From the viewpoint of reducing the resistance of the transparent conductive layer, the impurity metal in the composite metal oxide is preferably one having a higher valence electron number than the main metal. Examples of such composite metal oxides include indium-tin composite oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), and indium-doped zinc oxide (IZO). ) And the like. Among these, indium tin composite oxide is most preferably used from the viewpoint of forming a transparent conductive layer having low resistance and high transparency. Such an indium-tin composite oxide is characterized by high transmittance in the visible light region (380 nm to 780 nm) and low surface resistance per unit area.

As the transparent conductive layer, when using an indium-tin complex oxide, the amount of SnO ₂ is, to the weight plus the _In 2 _{O 3} and SnO _2, from 0.5 wt% to 15 wt% Preferably, it is 1 to 10% by weight, more preferably 2 to 6% by weight. If the amount of SnO ₂ is too small, the durability of the ITO film may be inferior. If the amount of SnO ₂ is too large, there is a tendency that the time required for crystallization increases.

  The transparent conductive layer may be crystalline or amorphous. For example, when a transparent resin film is used as a base material and an ITO film is formed as a transparent conductive layer by a sputtering method, sputtering film formation cannot be performed at a high temperature because there is a restriction due to the heat resistance of the base material. Therefore, the transparent conductive layer immediately after film formation is often an amorphous film (some of which may be crystallized). Such an amorphous transparent conductive layer may cause problems such as a low transmittance compared to a crystalline one and a large resistance change after the humidification heat test. From this point of view, after forming an amorphous transparent conductive layer, it may be converted into a crystalline film by heating in the presence of oxygen in the atmosphere. By crystallizing the transparent conductive layer, the transparency is improved, the resistance is lowered, and the humidification heat reliability is improved.

  The surface resistance value of the transparent conductive layer is preferably 400Ω / □ or less, more preferably 350Ω / □ or less, and further preferably 300Ω / □ or less. Such a transparent conductive film having a small surface resistance value is formed, for example, by forming an amorphous layer of an indium-tin composite oxide on a cured resin layer by sputtering or vacuum deposition, and then at 80 ° C. to 200 ° C. It is obtained by heat-treating at 30 ° C. for about 30 to 90 minutes to convert the amorphous transparent conductive layer to crystalline. The conversion means is not particularly limited, and an air circulation oven, an IR heater, or the like is used.

  Regarding the definition of “crystalline”, a transparent conductive film in which a transparent conductive layer is formed on a transparent resin film is immersed in hydrochloric acid having a concentration of 5% by weight at 20 ° C. for 15 minutes, then washed with water and dried for 15 mm. When the inter-terminal resistance is measured with a tester and the inter-terminal resistance does not exceed 10 kΩ, it is assumed that the conversion of the ITO film to crystalline is completed.

The thickness of the transparent conductive layer is not particularly limited, but in order to obtain a continuous film having good conductivity with a surface resistance of 1 × 10 ³ Ω / □ or less, the thickness is preferably 10 nm or more. When the film thickness becomes too thick, the transparency is lowered, and it is preferably 15 to 35 nm, more preferably in the range of 20 to 30 nm. When the thickness of the transparent conductive layer is less than 15 nm, the electrical resistance of the film surface increases and it becomes difficult to form a continuous film. Further, when the thickness of the transparent conductive layer exceeds 35 nm, the transparency may be lowered.

  The transparent conductive layer may be patterned by etching or the like. For example, in a transparent conductive film used for a capacitive touch panel or a matrix resistive touch panel, the transparent conductive layer is preferably patterned in a stripe shape. When the transparent conductive layer is patterned by etching, if the transparent conductive layer is first crystallized, patterning by etching may be difficult. Therefore, it is preferable to perform the annealing treatment of the transparent conductive layer after patterning the transparent conductive layer.

  In general, since the transparent conductive layer is formed of a metal oxide, the refractive index is high and the reflectance at the surface is high. For this reason, a difference in reflectance occurs between the pattern forming portion and the pattern opening, and the pattern tends to be easily recognized. On the other hand, by providing the optical adjustment layer 3 between the base film 1 and the transparent conductive layer 4, the reflected light on the surface of the transparent conductive layer is canceled out by interference due to interface multiple reflection, and the pattern forming portion The reflectance is reduced. Therefore, the difference in reflectance between the pattern forming portion and the pattern opening is reduced, and the pattern becomes difficult to be visually recognized.

  Although the reflectance of the transparent conductive film 10 can be appropriately set in consideration of optical characteristics required for the display module, it is preferably 1.2% or less, more preferably 1.0% or less, and 0.8%. The following is more preferable.

  The haze of the transparent conductive film is not particularly limited as long as the required transparency can be secured, but is preferably 5% or less, more preferably 4% or less, and even more preferably 3% or less. The lower limit of haze is preferably 0%, but may be 0.3% or more.

  In the present specification, “reflectance” represents the luminous reflectance Y of the D65 light source of the CIE color system.

<Method for producing transparent conductive film>
The method for producing a transparent conductive film according to the present embodiment comprises a step of applying a coating liquid for forming an optical adjustment layer on a base film to form a coating film,
A step of curing the coating film by energy ray irradiation to form an optical adjustment layer; and a step of forming a transparent conductive layer on the optical adjustment layer,
The energy beam irradiation is performed while running the base film,
The traveling speed v [m / min] of the base film and the integrated light amount L [mJ / cm ² ] of the energy ray satisfy the following relationship.
v <0.1L

(Coating film forming process)
In this step, a coating film is formed by applying a coating solution for forming an optical adjustment layer directly on the base film or via another layer such as a hard coat layer. The coating liquid for forming the optical adjustment layer is prepared by appropriately mixing the above-described organic-inorganic composite material, additives, and the like.

  As a coating method, it can be suitably formed by a general coating method such as a gravure coating method, a bar coating method, a fan ten coating, a die coating, a spin coating, a spray coating, a roll coating, or the like. Thus, it is preferable to form at least one optical adjustment layer by a coating method, but as a method for forming the remaining optical adjustment layer, in addition to the above-described coating method, a vacuum deposition method, a sputtering method, an ion plating method are used. A dry process such as the above may be employed.

(Optical adjustment layer forming step)
In this step, the coating film is cured by energy beam irradiation to form an optical adjustment layer. As the energy beam source, for example, a beam source such as a high pressure mercury lamp, a halogen lamp, a xenon lamp, a metal halide lamp, a nitrogen laser, an electron beam accelerator, or a radioactive element is used.

In this step, the energy beam irradiation is performed while the substrate film 1 on which the coating film is formed travels. At this time, the traveling speed v [m / min] of the base film 1 and the integrated light amount L [mJ / cm ² ] of the energy ray satisfy the following relationship.
v <0.1L

Furthermore, it is preferable that the traveling speed v [m / min] of the base film 1 and the integrated light amount L [mJ / cm ² ] of the energy ray satisfy the following relationship.
v <0.07L

By reducing the traveling speed of the base film 1 during the energy ray irradiation to a predetermined range, both the irradiation time of the energy rays and the inert gas replacement can be achieved at a high level and sufficiently cured. The optical adjustment layer 3 can be formed. For example, when the integrated light amount L [mJ / cm ² ] of the energy beam is 100 mJ / cm ² , the traveling speed of the base film is set to less than 10 m / min, and the integrated light amount L [mJ / cm ² ] of the energy beam is set. Is 200 mJ / cm ² , the running speed of the base film is set to less than 20 m / min.

The amount of irradiation with the energy radiation source is a cumulative amount of light L at an ultraviolet wavelength of 365 nm, preferably ^{200~500mJ / cm 2, 220~480mJ / cm} 2 is preferred. When the integrated light quantity L is less than the above lower limit value, curing becomes insufficient, and the hardness of the optical adjustment layer 3 may decrease. Moreover, when the said upper limit is exceeded, the optical adjustment layer 3 may color and transparency may fall.

  What is necessary is just to set the running speed v of the base film 1 so that the said relationship may be satisfy | filled, 10-35 m / min is preferable and 15-30 m / min is more preferable. If the traveling speed v exceeds the upper limit, the energy ray irradiation time and inert gas replacement become insufficient, and the coating film may not be sufficiently cured.

  In the optical adjustment layer forming step, the oxygen concentration in the vicinity of the coating film upon energy beam irradiation is preferably less than 100 ppm, more preferably 80 ppm or less, and even more preferably 60 ppm or less. Thereby, the hardening reaction of the coating film by irradiation of energy rays can be promoted, and an optical adjustment layer having a sufficient degree of hardening can be formed.

(Transparent conductive layer forming process)
In this step, the transparent conductive layer 4 is formed on the optical adjustment layer 3. The formation method of a transparent conductive layer is not specifically limited, A conventionally well-known method is employable. Specifically, for example, dry processes such as vacuum deposition, sputtering, and ion plating can be exemplified. In addition, an appropriate method can be adopted depending on the required film thickness.

<Touch panel>
The transparent conductive film 10 can be suitably applied to, for example, a capacitive touch panel or a resistive touch panel. In particular, even when the transparent conductive layer is patterned, the difference in visibility between the pattern forming portion and the pattern opening, particularly the difference in reflectance, can be kept small. It is suitably used for a touch panel including a transparent conductive layer patterned into a predetermined shape, such as a resistive film type touch panel capable of multipoint input.

  In forming the touch panel, a transparent substrate such as glass or a polymer film can be bonded to one or both main surfaces of the transparent conductive film via a transparent adhesive layer. The transparent substrate may be composed of a single substrate film or may be a laminate of two or more substrate films (for example, laminated via a transparent adhesive layer). A hard coat layer can also be provided on the outer surface of the transparent substrate to be bonded to the transparent conductive film.

  The pressure-sensitive adhesive layer used for bonding the transparent conductive film and the substrate can be used without particular limitation as long as it has transparency. Specifically, for example, acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy systems, fluorine systems, natural rubbers, rubbers such as synthetic rubbers, etc. Those having the above polymer as a base polymer can be appropriately selected and used. In particular, an acrylic pressure-sensitive adhesive is preferably used from the viewpoint that it is excellent in optical transparency, exhibits adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and is excellent in weather resistance and heat resistance.

  When the transparent conductive film according to the present invention is used for forming a touch panel, the handling property at the time of forming the touch panel is excellent. Therefore, a touch panel excellent in transparency and visibility can be manufactured with high productivity.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded. In the examples, unless otherwise indicated, “parts” means “parts by weight”.

<Example 1>
First, a refractive index adjusting agent (manufactured by JSR, trade name “OPSTAR Z7412”: an organic / inorganic composite material having a refractive index of 1.62 including zirconia particles having a median diameter of 40 nm as an inorganic component), which is an organic / inorganic composite component, is obtained. A coating solution for forming an optical adjustment layer diluted with butyl so as to have a solid content concentration of 4% by weight was prepared.

The coating liquid was applied to one side of a long base film 1 (product name “Zeonor”, manufactured by Nippon Zeon Co., Ltd.) having a thickness of 100 μm using a bar coater to form a coating film. While the base film 1 was running, the coating film was irradiated with ultraviolet rays, and the coating film was cured to form an optical adjustment layer having a thickness of nm and a refractive index of 1.62. The ultraviolet irradiation was performed with a high-pressure mercury lamp under the conditions of a line speed of 15 m / min and an integrated light amount of 230 mJ / cm ² . The oxygen concentration at that time was 60 to 70 ppm.

  Thereafter, a long base film having an optical adjustment layer was put into a take-up sputtering apparatus, and an indium tin oxide layer having a thickness of 20 nm (argon gas 98% and oxygen as a transparent conductive layer) was formed on the surface of the optical adjustment layer. In an atmosphere of 0.4 Pa composed of 2%, sputtering using a sintered body composed of 97% by weight of indium oxide and 3% by weight of tin oxide was laminated. This produced the transparent conductive film.

<Examples 2-4 and Comparative Examples 1-2>
A transparent conductive film was produced in the same manner as in Example 1 except that the refractive index adjusting agent for forming the optical adjustment layer, the line speed at the time of ultraviolet irradiation and the integrated light amount were as shown in Table 1.

[Evaluation]
The following evaluation was performed about each transparent conductive film obtained in Examples 1-4 and Comparative Examples 1-2. Each evaluation result is shown in Table 1.

(Evaluation of alkali resistance)
First, the transparent conductive layer was removed by immersing in a 10 wt% HCl aqueous solution heated to 50 ° C. to obtain a laminate (50 mm × 50 mm) as a sample for an alkali resistance test. Next, the laminate is immersed in an aqueous sodium hydroxide solution (7% by weight) heated to 50 ° C. for 10 minutes, and after 8 minutes, 9 minutes and 10 minutes, the laminate is taken out and placed in a dryer. And dried.

  The reflection spectrum before and after each immersion time of the laminate in the sodium hydroxide aqueous solution was measured. Specifically, using the integrating sphere measurement mode of the spectrophotometer “U-4100” (trade name) manufactured by Hitachi High-Tech, the incident angle to the optical adjustment layer is 2 degrees, and in the wavelength range of 200 to 800 nm. The reflection spectrum was measured. In the measurement, the light shielding layer is formed by bonding a black acrylic plate with an adhesive on the surface side of the base film on which the optical adjustment layer is not formed, and reflection from the back surface of the sample or from the back surface side. The measurement was performed with almost no light incident. In FIG. 2, the reflection spectrum before and behind alkali immersion (8 minutes) of Example 4 is shown. From the obtained reflection spectrum, the absolute value (| λ0−λ1 |: Δλ) of the difference between the wavelength λ0 [nm] at which the reflectance is minimum before immersion and the wavelength λ1 [nm] at which the reflectance is minimum after immersion. ) The case where Δλ was 20 nm or less was evaluated as “◯”, the case where it exceeded 20 nm and 50 nm or less was evaluated as “Δ”, and the case where it exceeded 50 nm was evaluated as “X”.

(Evaluation of wet heat resistance)
The produced transparent conductive film is held for 500 hours in a thermo-hygrostat (manufactured by Espec Corp., LHL-113) set at 85 ° C. and 85% RH, and evaluated according to the occurrence time of cracks in the transparent conductive layer. went. If the crack occurred after 240 hours, or if no crack occurred, “○”, double the crack occurred within 240 hours after “120”, and crack occurred within 120 hours. The case was evaluated as “×”.

  In the transparent conductive films of Examples 1 to 4, it was found that the alkali resistance was good and the optical adjustment layer was sufficiently cured. As a result, the heat and moisture resistance of the transparent conductive film was also excellent. In Comparative Examples 1 and 2, since the optical adjustment layer was not sufficiently cured, the evaluation of alkali resistance was low and the heat and moisture resistance was inferior. A comparison between Example 1 and Example 2 shows that when the integrated light quantity is constant, the slower the line speed, the lower the oxygen concentration and the better the alkali resistance result.

DESCRIPTION OF SYMBOLS 1 Base film 2 Hard-coat layer 3 Optical adjustment layer 4 Transparent conductive layer

Claims (7)

A base film, an optical adjustment layer that is a coating film, and a transparent conductive layer are provided in this order,
When the reflection spectrum before and after immersing the laminate after removing the transparent conductive layer in a 7% by weight aqueous sodium hydroxide solution at 50 ° C. for 8 minutes was measured, the wavelength λ 0 [ nm] and a transparent conductive film having an absolute value of the difference between the wavelength λ1 [nm] at which the reflectance is minimum after immersion is 50 nm or less. The optical adjustment layer is formed of an organic-inorganic composite material including an organic component and an inorganic component,
The transparent conductive film according to claim 1, wherein the median diameter value of the inorganic component is smaller than the thickness value of the optical adjustment layer.   The hard coat layer is formed in at least one of the surface side on the opposite side to the said optical adjustment layer of the said base film between the said base film and the said optical adjustment layer of Claim 1 or 2. Transparent conductive film.   The transparent conductive film according to claim 1, wherein the base film contains a cycloolefin-based resin. A step of forming a coating film by applying a coating liquid for forming an optical adjustment layer on a base film;
A step of curing the coating film by energy ray irradiation to form an optical adjustment layer; and a step of forming a transparent conductive layer on the optical adjustment layer,
The energy beam irradiation is performed while running the base film,
The manufacturing method of the transparent conductive film with which the travel speed v [m / min] of the said base film and the integrated light quantity L [mJ / cm < ² >] of the said energy ray satisfy | fill the following relationship.
v <0.1L   The method for producing a transparent conductive film according to claim 5, wherein an oxygen concentration in the vicinity of the coating film at the time of the energy ray irradiation is less than 100 ppm. A touch panel provided with the transparent conductive film of any one of Claims 1-4.

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