JP6626996B2 - Transparent conductive film, transparent conductive film laminate, and touch panel - Google Patents

Description

  The present invention relates to a transparent conductive film, a transparent conductive film laminate, and a touch panel, and is a technique particularly useful for controlling the occurrence of curling.

  Conventionally, as a substrate for a liquid crystal display, an organic electroluminescence display, a touch panel, or the like, a glass substrate is often used. In recent years, with a reduction in thickness of a display, attention has been paid to a reduction in thickness of a glass substrate having excellent transparency, surface smoothness, heat resistance, and the like.

  On the other hand, in a capacitance type touch panel configuration, polyethylene terephthalate (PET) is widely used as a base film of a transparent conductive film. However, since the PET film is formed by stretching and has a high retardation, it is difficult to use the PET film under a polarizing plate. Therefore, Patent Document 1 proposes a transparent conductive film using a cycloolefin-based resin as an amorphous resin as a base film for low retardation.

  Patent Document 2 discloses a transparent conductive film in which a transparent conductive film is formed on a polycarbonate or amorphous polyolefin film as a λ / 4 retardation film that can be used under a polarizing plate such as a liquid crystal display. There have been proposed a laminate in which a transparent conductive film is laminated on a glass substrate, and a liquid crystal display device in which a touch panel function is provided on a flexible cover glass over the entire surface.

  After laminating the transparent conductive film to a thin glass substrate to form a transparent conductive film laminate, or when performing crystallization of the transparent conductive film or performing metal wiring processing for frame wiring, a temperature of 130 ° C. or more Often through a heating step. In such a case, the thin glass substrate is susceptible to the influence of heating, and since the resin and the glass have different heat shrinkage ratios, the laminate is curled and cannot be transported to the next step, or the metal wiring is not aligned. Adjustment is difficult and metal wiring cannot be processed, making it difficult to perform stable and continuous production.

JP 2013-114344 A JP 2014-137427 A

  Accordingly, an object of the present invention is to provide a transparent conductive film laminate in which a thin glass substrate is bonded to a transparent conductive film, in which a curl can be suppressed even after a heating step, and a transparent conductive film capable of ensuring a subsequent process yield. An object of the present invention is to provide a conductive film, a transparent conductive film laminate, and a touch panel.

  The present inventors have conducted intensive studies to solve the above-described problems, and as a result, when the transparent conductive film laminate curled greatly in the concave direction when the transparent conductive film was placed on top, the transparent conductive film of the transparent conductive film was placed below. The present inventors have found that the above object can be achieved by designing the transparent conductive film so as to curl largely in the concave direction in advance in the case where the present invention is performed.

  That is, in the transparent conductive film of the present invention, the first cured resin layer and the transparent conductive film are formed in this order on one surface side of the transparent resin film, and the second cured resin layer is formed on the other surface side of the transparent resin film. A transparent resin film having a cured resin layer formed thereon, wherein the transparent resin film is made of an amorphous resin, and the transparent conductive film is cut into 50 cm × 50 cm, and the transparent conductive film is placed on the lower surface at 130 ° C. The transparent conductive film is characterized in that the difference (A−B) between the average curl value A at the four corners and the curl value B at the central part after heating for 90 minutes at (A−B) is 5 mm or more. In addition, various physical property values in the present invention are values measured by a method adopted in Examples and the like, unless otherwise specified.

  The amorphous resin forming the transparent resin film is generally formed through an extrusion process or a cast film forming process, and a residual stress always remains, and shrinkage stress is generated by heating. On the other hand, thin glass has overwhelmingly small shrinkage stress when heated to about 130 ° C. Therefore, in a transparent conductive film laminate in which thin glass is adhered to a transparent conductive film, when the transparent conductive film is heated with the transparent conductive film facing upward, curl occurs in a concave direction. Further, in the transparent conductive film, curl due to heating occurs because the transparent conductive film, which is an inorganic substance, and the transparent resin film, which is an organic substance, have different thermal contraction rates and linear expansion coefficients. Therefore, in the present invention, the transparent conductive film of the transparent conductive film is designed so as to curl largely in the concave direction in advance when the transparent conductive film is placed on the lower side. It has been found that curling can be extremely reduced. That is, the difference between the average curl value A at the four corners and the curl value B at the center after the transparent conductive film was cut into 50 cm × 50 cm and heated at 130 ° C. for 90 minutes with the transparent conductive film on the lower surface (A− When B) is at least 5 mm, the shrinkage force that would have been generated in the laminate laminated on the conventional glass substrate and the shrinkage force generated in the transparent conductive film can be canceled each other, and the thin glass The curl after the heating step can be extremely reduced in the transparent conductive film laminate after being bonded to the substrate. This makes it possible to suppress curling after heating due to crystallization of the transparent conductive film, metal wiring processing, or the like, and it is possible to stably and continuously process and carry, and to secure the subsequent process yield.

  In the transparent conductive film of the present invention, the thickness of the first cured resin layer and the thickness of the second cured resin layer are each 2 μm or less, and the thickness of the second cured resin layer is It is preferable that the thickness is equal to or smaller than the thickness of the cured resin layer. When the thickness of the first cured resin layer and the thickness of the second cured resin layer are as thin as described above, the effect of the shrinkage caused by the cured resin layer can be reduced, and the transparent resin film is It is more susceptible to the effects of heating and curling is more likely to occur. Further, when the thickness of the second cured resin layer is the same as or smaller than the thickness of the first cured resin layer, the transparent resin film is more susceptible to the influence of heating, and the curl is more likely to occur. A transparent conductive film can be designed.

The transparent conductive film of the present invention preferably further comprises one or more optical adjustment layers between the first cured resin layer and the transparent conductive film. Since the refractive index can be controlled by the optical adjustment layer, even when the transparent conductive film is patterned, the difference in reflectance between the pattern forming portion and the pattern opening can be reduced, and the transparent conductive film pattern is difficult to see, and the The visibility is improved in the display device.
After applying the optical adjustment layer, the film is passed through an annealing step to adjust the difference in the substrate thermal shrinkage in the MD and TD directions and to reduce the shrinkage force of the substrate, so that the curl amount is more easily generated. Conductive films can be designed.

  The second cured resin layer in the invention preferably contains a resin and particles. Thereby, the anti-blocking property that can withstand the roll-to-roll manufacturing method can be more reliably realized, and the transportability can be improved.

  In the transparent resin film according to the present invention, the amorphous resin is a cycloolefin-based resin, the thickness is 20 to 75 μm, the glass transition temperature is 130 ° C. or higher, and the transparent conductive film is at 130 ° C. for 90 minutes. Is preferably less than 0.2% in the MD and TD directions after heating. Since the thickness of the transparent resin film is in a relatively thin range, the transparent conductive film can be designed so as to be more susceptible to the influence of heating and to cause curling. In addition, by using a cycloolefin resin having a high glass transition temperature and using a transparent conductive film having a small heat shrinkage, excessive heat shrinkage after the heating step can be suppressed, and curling at a higher level can be suppressed. Can control the occurrence.

  The optical adjustment layer in the invention preferably contains a binder resin and fine particles, has a refractive index of 1.6 to 1.8, and has a thickness of 40 to 150 nm. By including the fine particles in the optical adjustment layer, the refractive index of the optical adjustment layer itself can be easily adjusted. Further, by setting the thickness of the optical adjustment layer within the above range, a continuous film can be easily formed, transparency can be ensured, and control can be performed so as not to greatly affect the occurrence of curling.

  The transparent conductive film in the present invention is made of indium-tin composite oxide (ITO), and preferably has a thickness of 10 to 35 nm. Thereby, transparency can be secured, visibility can be improved even when used for a touch panel or the like, and the direction and amount of curl generation can be designed.

  The transparent conductive film laminate of the present invention is preferably a transparent conductive film laminate in which a glass substrate is laminated via an adhesive layer on the surface of the transparent conductive film opposite to the transparent conductive film. Since the transparent conductive film of the present invention is designed so as to curl largely in the concave direction in advance when the transparent conductive film is placed on the lower side, the curl after the heating step is applied to the transparent conductive film laminate laminated with thin glass. Can be suppressed, and the subsequent process yield can be ensured.

  The difference between the average curl value A at the four corners and the curl value B at the center after the transparent conductive film laminate of the present invention was cut into 210 mm × 260 mm and heated at 130 ° C. for 90 minutes with the transparent conductive film on the upper surface. (AB) is preferably 2.0 mm or less. Thereby, the occurrence of curl can be suppressed even after the heating step, and the subsequent process yield can be secured.

  The touch panel of the present invention is preferably obtained using the transparent conductive film laminate. When the transparent conductive film laminate is used, curling after a heating step such as drying can be suppressed, so that the processing and conveyance of the transparent conductive film laminate are facilitated, and the working efficiency is improved.

FIG. 1 is a schematic sectional view of a transparent conductive film according to one embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention. It is a typical sectional view of the transparent conductive film layered product concerning one embodiment of the present invention.

  An embodiment of the transparent conductive film laminate of the present invention will be described below with reference to the drawings. However, in some or all of the drawings, portions unnecessary for description are omitted, and some portions are illustrated in an enlarged or reduced manner for easy description. Terms indicating a positional relationship such as up and down are used merely for ease of explanation, and there is no intention to limit the configuration of the present invention.

<Structure of transparent conductive film and laminate>
FIG. 1 is a cross-sectional view schematically illustrating one embodiment of the transparent conductive film of the present invention, and FIG. 2 is a cross-sectional view schematically illustrating another embodiment of the transparent conductive film of the present invention. FIG. 3 is a cross-sectional view schematically showing one embodiment of the transparent conductive film laminate of the present invention. The transparent conductive film 10 shown in FIGS. 1 and 2 has a first cured resin layer 2 and a transparent conductive film 3 formed in this order on one surface side of the transparent resin film 1, and the other of the transparent resin film 1. The second cured resin layer 4 is formed on the side of the surface. As shown in FIG. 2, one optical adjustment layer 5 can be further provided between the first cured resin layer 2 and the transparent conductive film 3, but two or more optical adjustment layers 5 are provided. You can also. The first cured resin layer 2 and the second cured resin layer 4 include those that function as an anti-blocking layer or a hard coat layer. Further, as shown in FIG. 3, in the transparent conductive film laminate, a glass substrate 6 is laminated on a surface of the transparent conductive film 10 opposite to the transparent conductive film 3 via an adhesive layer 7.

<Transparent conductive film>
In the transparent conductive film, a first cured resin layer and a transparent conductive film are formed in this order on one surface side of the transparent resin film, and a second cured resin layer is formed on the other surface side of the transparent resin film. Is formed. One or more optical adjustment layers may be further included between the first cured resin layer and the transparent conductive film. In the transparent conductive film, the heat shrinkage in the MD and TD directions when heated at 130 ° C. for 90 minutes is preferably less than 0.2%, more preferably 0.2% or less, and 0%. .15% or less, more preferably 0.1% or less. The lower limit is not particularly limited, but is preferably 0.01% or more. As a result, a transparent conductive film having excellent workability and transparency can be obtained, and the amount and direction of curl after a heating step such as drying can be controlled, so that the processing and transport of the transparent conductive film laminate are facilitated.

  The difference between the average curl value A at the four corners and the curl value B at the center after the transparent conductive film was cut into 50 cm × 50 cm and heated at 130 ° C. for 90 minutes with the transparent conductive film on the lower surface (AB). Is preferably at least 5 mm, more preferably at least 8 mm, even more preferably at least 10 mm. The upper limit is not particularly limited, but is preferably 50 mm or less, more preferably 40 mm or less, and still more preferably 30 mm or less. When the curl amount of the transparent conductive film is set to be large as described above, the curl after the heating step in the transparent conductive film laminate after being bonded to the thin glass substrate can be extremely reduced. This makes it possible to suppress curling after heating due to crystallization of the transparent conductive film, metal wiring processing, or the like, and it is possible to stably and continuously process and carry, and to secure the subsequent process yield.

(Transparent resin film)
The transparent resin film is formed of an amorphous resin and has high transparency and low water absorption properties. The use of the amorphous resin makes it possible to control the optical properties of the transparent conductive film. The amorphous resin is not particularly limited, but preferably has excellent transparency, mechanical strength, heat stability, moisture barrier properties, isotropy, and the like, and includes polycarbonate, cycloolefin, polyvinyl chloride, and the like. Acrylic resin such as polymethyl methacrylate, polystyrene, polymethyl methacrylate styrene copolymer, polyacrylonitrile, polyacrylonitrile styrene copolymer, high impact polystyrene (HIPS), acrylonitrile butadiene styrene copolymer (ABS resin), poly Arylate, polysulfone, polyethersulfone, polyphenylene ether and the like can be mentioned. From the viewpoints of high transparency, low water absorption, heat resistance, and the like, cycloolefin-based resins and polycarbonate-based resins are preferred.

  The cycloolefin-based resin is not particularly limited as long as it has a monomer unit composed of a cyclic olefin (cycloolefin). The cycloolefin resin used for the transparent resin film may be either a cycloolefin polymer (COP) or a cycloolefin copolymer (COC). The cycloolefin copolymer refers to a non-crystalline cyclic olefin resin which is a copolymer of a cyclic olefin and an olefin such as ethylene.

  The cyclic olefin includes a polycyclic cyclic olefin and a monocyclic cyclic olefin. Examples of such polycyclic olefins include norbornene, methylnorbornene, dimethylnorbornene, ethylnorbornene, ethylidene norbornene, butylnorbornene, dicyclopentadiene, dihydrodicyclopentadiene, methyldicyclopentadiene, dimethyldicyclopentadiene, and tetracyclododecene. , Methyltetracyclododecene, dimethylcyclotetradodecene, tricyclopentadiene, tetracyclopentadiene and the like. In addition, examples of the monocyclic olefin include cyclobutene, cyclopentene, cyclooctene, cyclooctadiene, cyclooctatriene, and cyclododecatriene.

  The cycloolefin-based resin is also available as a commercial product, and examples thereof include "ZEONOR" manufactured by Zeon Corporation, "ARTON" manufactured by JSR, "TOPAS" manufactured by Polyplastics, and "APEL" manufactured by Mitsui Chemicals. Can be

  The polycarbonate resin is not particularly limited, and examples thereof include aliphatic polycarbonate, aromatic polycarbonate, and aliphatic-aromatic polycarbonate. Specifically, for example, as a 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 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. Commercially available polycarbonate resins include "Opcon" manufactured by Keiwasha, "Panlite" manufactured by Teijin Limited, and "Iupilon (polycarbonate containing an ultraviolet absorber)" manufactured by Mitsubishi Gas Chemical.

  The transparent resin film is subjected to etching or undercoating treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, etc. on the surface in advance, so that the cured resin layer or transparent layer formed on the transparent resin film You may make it improve the adhesiveness with a conductive film etc. Before forming the cured resin layer or the transparent conductive film, the surface of the transparent resin film may be dust-removed and cleaned by solvent cleaning or ultrasonic cleaning as necessary.

  The thickness of the transparent resin film is preferably in the range of 20 to 75 μm, more preferably in the range of 25 to 70 μm, and even more preferably in the range of 30 to 65 μm. When the thickness of the transparent resin film is less than the lower limit of the above range, the mechanical strength is insufficient, and it may be difficult to form a roll of the film substrate and continuously form the transparent conductive film. On the other hand, if the thickness exceeds the upper limit of the above range, the scratch resistance of the transparent conductive film and the hitting characteristics for touch panels may not be improved. Also, if the thickness is within the above range, it is more susceptible to the effect of heating, so when the transparent conductive film of the transparent conductive film is placed down, it can be designed to curl largely in the concave direction in advance, and thin glass can be formed. Curling after the heating step can be suppressed when the transparent conductive film laminate is laminated.

  The glass transition temperature (Tg) of the amorphous resin of the transparent resin film is not particularly limited, but is preferably 130 ° C. or higher, more preferably 150 ° C. or higher, even more preferably 160 ° C. or higher. This makes it possible to suppress the occurrence of curling after a heating step such as drying when forming the transparent conductive film laminate, thereby facilitating the processing and transport of the transparent conductive film laminate.

  The heat shrinkage in the MD direction and the TD direction when the resin film raw material forming the transparent resin film (the film before the heat treatment or the like before laminating the cured resin layer) is heated at 130 ° C. for 90 minutes, It is preferably at most 0.3%, more preferably at most 0.2%, even more preferably at most 0.1%. As a result, a transparent resin film having excellent workability, transparency, dimensional stability during heating, and the like is obtained. Further, when the transparent conductive film laminate is formed, curling after a heating step such as drying can be suppressed, so that the processing and transport of the transparent conductive film laminate are facilitated.

  The transparent resin film can be easily formed into a low retardation film having an in-plane retardation (R0) of 0 nm to 10 nm or a λ / 4 film having an in-plane retardation of about 80 nm to 150 nm. When used together, it is possible to improve visibility. The in-plane retardation (R0) refers to an in-plane retardation value of a retardation film (layer) measured at 23 ° C. with light having a wavelength of 589 nm.

(Cured resin layer)
The cured resin layer includes a first cured resin layer formed on one side of the transparent resin film, and a second cured resin layer formed on the other side. A transparent resin film formed of an amorphous resin is easily damaged in each step such as formation of a transparent conductive film, patterning of the transparent conductive film or mounting on an electronic device. A first cured resin layer and a second cured resin layer are formed on both surfaces of the substrate.

  The cured resin layer is a layer obtained by curing a curable resin. The cured resin layer preferably contains a resin and particles. As the resin to be used, a resin having sufficient strength as a film after the formation of the cured resin layer and having transparency can be used without particular limitation, but a thermosetting resin, an ultraviolet curing resin, an electron beam curing resin, a two-component resin, Mixed type resins and the like can be mentioned. Among these, a UV-curable resin that can efficiently form a cured resin layer with a simple processing operation by a curing treatment by UV irradiation is preferable.

  Examples of the UV-curable resin include various resins such as polyester, acrylic, urethane, amide, silicone, and epoxy resins, and include UV-curable monomers, oligomers, and polymers. The UV-curable resin preferably used is an acrylic resin or an epoxy resin, and more preferably an acrylic resin.

  The cured resin layer may include particles. By incorporating particles into the cured resin layer, a bump can be formed on the surface of the cured resin layer, and the transparent conductive film can be suitably provided with blocking resistance.

  As the particles, those having transparency, such as various metal oxides, glass, and plastics, can be used without particular limitation. For example, silica, alumina, titania, zirconia, inorganic particles such as calcium oxide, polymethyl methacrylate, polystyrene, polyurethane, acrylic resin, acrylic-styrene copolymer, benzoguanamine, melamine, cross-linked or not formed of various polymers such as polycarbonate. Examples include crosslinked organic particles and silicone particles. One or more kinds of the particles can be appropriately selected and used, but organic particles are preferable. As the organic particles, an acrylic resin is preferable from the viewpoint of the refractive index.

  The mode particle size of the particles can be appropriately set in consideration of the degree of protrusion of the protrusion of the cured resin layer and the thickness of the flat region other than the protrusion, and is not particularly limited. In addition, the mode particle diameter of the particles is preferably 0.5 to 5 μm, from the viewpoint of sufficiently imparting blocking resistance to the transparent conductive film and sufficiently suppressing the increase in haze. More preferably, it is 0 to 2 μm. In this specification, the “mode particle size” refers to a particle size showing the maximum value of the particle distribution, and is measured using a flow type particle image analyzer (manufactured by Sysmex, product name “FPTA-3000S”). Under a predetermined condition (Sheath liquid: ethyl acetate, measurement mode: HPF measurement, measurement method: total count). As a measurement sample, one obtained by diluting particles to 1.0% by weight with ethyl acetate and uniformly dispersing the diluted particles using an ultrasonic cleaner is used.

  The content of the particles is preferably 0.05 to 1.0 part by weight, more preferably 0.1 to 0.5 part by weight, and more preferably 0.2 to 0.5 part by weight based on 100 parts by weight of the resin solid content. More preferably, it is 0.3 parts by weight. When the content of the particles in the cured resin layer is small, it is difficult to form a sufficient bump on the surface of the cured resin layer to impart anti-blocking properties and slipperiness. On the other hand, when the content of the particles is too large, the haze of the transparent conductive film is increased due to light scattering by the particles, and the visibility tends to decrease. On the other hand, if the content of the particles is too large, streaks are generated at the time of forming the cured resin layer (at the time of applying the solution), and the visibility is impaired, and the electrical characteristics of the transparent conductive film become uneven. There are cases.

  The cured resin layer is a resin composition containing particles, a crosslinking agent, an initiator, a sensitizer, etc., added to each of the curable resins and, if necessary, a transparent resin film, and when the resin composition contains a solvent. Is obtained by drying the solvent and curing it by applying either heat, active energy rays or both. For the heat, known means such as an air circulation oven and an IR heater can be used, but the method is not limited to these methods. Examples of the active energy ray include, but are not particularly limited to, ultraviolet rays, electron beams, and gamma rays.

  The cured resin layer can be formed from the above-mentioned materials by a wet coating method (coating method) or the like. For example, in the case where indium oxide (ITO) containing tin oxide is formed as the transparent conductive film, the crystallization time of the transparent conductive film can be reduced if the surface of the cured resin layer as the underlayer is smooth. From such a viewpoint, the cured resin layer is preferably formed by a wet coating method.

  Each of the thickness of the first cured resin layer and the thickness of the second cured resin layer is preferably 2 μm or less, more preferably 0.1 μm to 1.5 μm, and still more preferably 0.3 μm to 1.2 μm. The thickness of the second cured resin layer is preferably equal to or smaller than the thickness of the first cured resin layer. That is, the thickness of the second cured resin layer is preferably 10 to 100%, more preferably 20 to 90%, and more preferably 30 to 80% of the thickness of the first cured resin layer. More preferred. This can prevent the transparent resin film from being damaged when transported by the roll-to-roll manufacturing method. Further, when the thickness of the cured resin layer is within the above range, it is possible to prevent the visibility of the touch panel or the like from being deteriorated, and to curl largely in the concave direction in advance when the transparent conductive film of the transparent conductive film is placed below. Therefore, when thin glass is laminated to form a transparent conductive film laminate, curling after the heating step can be suppressed.

(Transparent conductive film)
The transparent conductive film can be provided on the transparent resin film, but is preferably provided on the first cured resin layer provided on one surface side of the transparent resin film. The constituent material of the transparent conductive film is not particularly limited as long as it contains an inorganic substance, and is formed from a group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium and tungsten. A metal oxide of at least one selected metal is preferably used. The metal oxide may further contain the metal atom shown in the above group, if necessary. For example, indium oxide containing tin oxide (ITO), tin oxide containing antimony (ATO), and the like are preferably used.

Although the thickness of the transparent conductive film is not particularly limited, it is preferable that the thickness be 10 to 35 nm in order to form a continuous film having a good surface conductivity of 1 × 10 ³ Ω / □ or less. When the film thickness is too large, the transparency is lowered. For example, the film thickness is preferably 15 to 35 nm, and more preferably 20 to 30 nm. When the thickness of the transparent conductive film is less than 10 nm, the electric resistance of the film surface increases, and it is difficult to form a continuous film. On the other hand, if the thickness of the transparent conductive film exceeds 35 nm, the transparency may be reduced. In addition, by forming the transparent conductive film with the above thickness on the first cured resin layer, the transparent conductive film can be designed so as to curl largely in the concave direction in advance when the transparent conductive film is placed below.

  The method for forming the transparent conductive film is not particularly limited, and a conventionally known method can be employed. Specifically, a dry process such as a vacuum deposition method, a sputtering method, and an ion plating method can be exemplified. Further, an appropriate method can be adopted according to a required film thickness.

  The transparent conductive film can be crystallized by performing a heat annealing treatment (for example, at 80 to 150 ° C. for about 30 to 90 minutes in an air atmosphere) as necessary. By crystallizing the transparent conductive film, the resistance and the transparency of the transparent conductive film are improved, and the transparency and durability are improved. The means for converting the amorphous transparent conductive film to crystalline is not particularly limited, but an air circulation oven, an IR heater, or the like is used.

  Regarding the definition of “crystalline”, a transparent conductive film having a transparent conductive film formed on a transparent resin film is immersed in hydrochloric acid having a concentration of 5% by weight at 20 ° C. for 15 minutes, washed with water and dried, and dried for 15 mm. Is measured by a tester. If the inter-terminal resistance does not exceed 10 kΩ, it is assumed that the conversion of the ITO film to crystalline has been completed. The surface resistance can be measured by a four-terminal method according to JIS K7194.

  Further, the transparent conductive film may be patterned by etching or the like. The patterning of the transparent conductive film can be performed using a conventionally known photolithography technique. An acid is preferably used as an etching solution. Examples of the acid include an inorganic acid such as hydrogen chloride, hydrogen bromide, sulfuric acid, nitric acid, and phosphoric acid, an organic acid such as acetic acid, a mixture thereof, and an aqueous solution thereof. For example, in a transparent conductive film used for a capacitance type touch panel or a matrix type resistance film type touch panel, it is preferable that the transparent conductive film is patterned in a stripe shape. In the case where the transparent conductive film is patterned by etching, if the transparent conductive film is first crystallized, patterning by etching may be difficult. Therefore, the annealing of the transparent conductive film is preferably performed after patterning the transparent conductive film.

(Optical adjustment layer)
One or more optical adjustment layers may be further included between the first cured resin layer and the transparent conductive film. The optical adjustment layer increases the transmittance of the transparent conductive film, and when the transparent conductive film is patterned, the transmittance difference and the reflectance difference between the pattern portion where the pattern remains and the opening where the pattern does not remain. And can be used to obtain a transparent conductive film having excellent visibility.

  The optical adjustment layer preferably contains a binder resin and fine particles. Examples of the binder resin contained in the optical adjustment layer include an acrylic resin, a urethane resin, a melamine resin, an alkyd resin, a siloxane polymer, an organic silane condensate, and the like, and an ultraviolet curable resin including an acrylic resin. preferable.

  The refractive index of the optical adjustment layer is preferably from 1.6 to 1.8, more preferably from 1.62 to 1.78, even more preferably from 1.65 to 1.75. Thereby, a difference in transmittance and a difference in reflectance can be reduced, and a transparent conductive film excellent in visibility can be obtained.

  The optical adjustment layer may have fine particles having an average particle size of 1 nm to 500 nm. The content of the fine particles in the optical adjustment layer is preferably from 0.1% by weight to 90% by weight. The average particle diameter of the fine particles used for the optical adjustment layer is preferably in the range of 1 nm to 500 nm, and more preferably 5 nm to 300 nm, as described above. Further, the content of the fine particles in the optical adjustment layer is more preferably from 10% by weight to 80% by weight, and further preferably from 20% by weight to 70% by weight. By including fine particles in the optical adjustment layer, the refractive index of the optical adjustment layer itself can be easily adjusted.

  Examples of the inorganic oxide forming fine particles include fine particles such as silicon oxide (silica), hollow nanosilica, titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide, and niobium oxide. Among them, fine particles of silicon oxide (silica), titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide, and niobium oxide are preferable, and zirconium oxide is more preferable. These may be used alone or in combination of two or more.

The optical adjustment layer can contain other inorganic substances. As an inorganic substance, NaF
(1.3), Na ₃ AlF ₆ (1.35), LiF (1.36), MgF ₂ (1.38), CaF ₂ (1.4), BaF ₂ (1.3), BaF ₂ ( 1.3), LaF ₃ (1.55), CeF (1.63), and the like (numerical values in parentheses indicate a refractive index).

  The optical adjustment layer can be formed from the above materials by a coating method such as a wet coating method, a gravure coating method or a bar coating method, a vacuum evaporation method, a sputtering method, or an ion plating method. For example, in the case where indium oxide (ITO) containing tin oxide is formed as the transparent conductive film, the crystallization time of the transparent conductive layer can be reduced if the surface of the resin layer serving as the base layer is smooth. From such a viewpoint, the resin layer is preferably formed by a wet coating method.

  The thickness of the optical adjustment layer is preferably from 40 nm to 150 nm, more preferably from 50 nm to 130 nm, even more preferably from 70 nm to 120 nm. If the thickness of the optical adjustment layer is too small, it is difficult to form a continuous film. Further, when the thickness of the optical adjustment layer is excessively large, the transparency of the transparent conductive film tends to decrease, and cracks tend to occur.

(Metal wiring)
The metal wiring can be formed by etching after forming the metal layer on the transparent conductive film, but is preferably formed using a photosensitive metal paste as described below. That is, after the transparent conductive film is patterned, the metal wiring is coated with a photosensitive conductive paste described later on the transparent resin film or the transparent conductive film to form a photosensitive metal paste layer, and a photomask is formed. The photosensitive metal paste layer is exposed to light through a photomask after being laminated or brought close to the photosensitive metal paste layer, followed by development, pattern formation, and a drying step. That is, a metal wiring pattern can be formed by a known photolithography method or the like.

  The photosensitive conductive paste preferably contains conductive particles such as metal powder and a photosensitive organic component. The material of the conductive particles of the metal powder preferably contains at least one selected from the group consisting of Ag, Au, Pd, Ni, Cu, Al and Pt, and is more preferably Ag. The volume average particle diameter of the conductive particles of the metal powder is preferably 0.1 μm to 2.5 μm.

  As the conductive particles other than the metal powder, metal-coated resin particles obtained by coating the surface of a resin particle with a metal may be used. As the material of the resin particles, the above-described particles are included, and an acrylic resin is preferable. Metal-coated resin particles are obtained by reacting a silane coupling agent on the surface of the resin particles and coating the surface with a metal. By using a silane coupling agent, the dispersion of the resin component is stabilized, and uniform metal-coated resin particles can be formed.

The photosensitive conductive paste may further include a glass frit. The glass frit preferably has a volume average particle size of 0.1 μm to 1.4 μm, a 90% particle size of 1 to 2 μm, and a top size of 4.5 μm or less. Although the composition of the glass frit is not particularly limited, it is preferable that Bi ₂ O ₃ is blended in a range of 30% by weight to 70% by weight based on the whole. The oxides that may be included in addition to Bi ₂ O ₃ may include SiO ₂ , B ₂ O ₃ , ZrO ₂ , and Al ₂ O ₃ . It is preferable to be an alkali-free glass frit substantially free of Na ₂ O, K ₂ O, and Li ₂ O.

  The photosensitive organic component preferably contains a photosensitive polymer and / or a photosensitive monomer. Examples of the photosensitive polymer include a polymer of a component selected from compounds having a carbon-carbon double bond such as methyl (meth) acrylate and ethyl (meth) acrylate, and a side chain or molecule of an acrylic resin composed of a copolymer thereof. Those having a photoreactive group added to the terminal are suitably used. Preferred photoreactive groups include ethylenically unsaturated groups such as vinyl, allyl, acryl and methacryl. The content of the photosensitive polymer is preferably 1 to 30% by weight and 2 to 30% by weight.

  Examples of the photosensitive monomer include (meth) acrylate monomers such as methacryl acrylate and ethyl acrylate, γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone, and the like. One or more kinds are used. can do.

  In the photosensitive conductive paste, the photosensitive organic component preferably contains 5 to 40% by weight based on 100 parts by weight of the metal powder from the viewpoint of light sensitivity, and more preferably 10 to 30 parts by weight. The photosensitive conductive paste of the present invention preferably uses a photopolymerization initiator, a sensitizer, a polymerization inhibitor, and an organic solvent as necessary.

  The thickness of the metal layer is not particularly limited. For example, when pattern wiring is formed by removing a part of the surface of the metal layer by etching or the like, the thickness of the metal layer is appropriately set so that the formed pattern wiring has a desired resistance value. Therefore, the thickness of the metal layer is preferably 0.01 to 200 μm, and more preferably 0.05 to 100 μm. When the thickness of the metal layer is within the above range, the resistance of the pattern wiring does not become too high, and the power consumption of the device does not increase. In addition, the production efficiency of forming the metal layer is increased, the integrated heat amount during the film formation is reduced, and the film is less likely to generate thermal wrinkles.

  When the transparent conductive film is a transparent conductive film for a touch panel used in combination with a display, a portion corresponding to a display portion is formed by a patterned transparent conductive film, and a metal wiring made from a photosensitive conductive paste. Is used for a wiring portion of a non-display portion (for example, a peripheral portion). The transparent conductive film may be used in a non-display portion, and in that case, a metal wiring may be formed on the transparent conductive film.

<Transparent conductive film laminate>
The transparent conductive film laminate is formed by laminating a glass substrate via an adhesive layer on the other side of the transparent conductive film from the transparent conductive film. The transparent conductive film laminate was obtained by cutting the transparent conductive film laminate into a piece having a size of 210 mm × 260 mm, heating the transparent conductive film on the upper surface at 130 ° C. for 90 minutes, and then calculating the average curl value A at the four corners and the curl at the center. The difference (A−B) from the value B is preferably 2.0 mm or less, more preferably less than 2.0 mm, and even more preferably 1.8 mm or less. The lower limit is not particularly limited, but is preferably 0.5 mm or more. When the curl amount is suppressed in this manner, air can be sucked when the transparent conductive film laminate is transported, and processing and transport can be continuously performed.

(Glass substrate)
The glass substrate has a transparent conductive film laminated on the other side of the transparent conductive film from the transparent conductive film via an adhesive layer. The material for forming the glass substrate is not particularly limited, but preferably has excellent transparency, surface smoothness, heat stability, moisture barrier properties, isotropy, and the like, and examples thereof include soda lime glass and borosilicate glass. . These glasses may be chemically strengthened and may have an alkali elution preventing layer formed on the surface. Further, the glass surface may be treated with a silane coupling agent in order to increase the adhesive strength with another layer.

  The thickness of the glass substrate is preferably from 0.1 to 1.5 mm, more preferably from 0.3 to 1.0 mm. If the thickness is too thin, the glass is likely to be damaged when the transparent conductive film laminate is heated, while if it is too thick, it becomes difficult to reduce the thickness of the display and the flexibility is reduced. A glass substrate having a thickness in such a range is bonded to a transparent conductive film designed to curl largely in a concave direction in advance when the transparent conductive film is placed downward, thereby producing a transparent conductive film laminate, thereby performing a heating step. Later curl generation can be suppressed.

(Adhesive layer)
As the pressure-sensitive adhesive layer, the following pressure-sensitive adhesives can be used without particular limitation as long as they have transparency. Specific examples of the pressure-sensitive adhesive include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy-based, fluorine-based, natural rubber, and synthetic rubbers. A polymer having a base polymer such as a rubber-based polymer can be appropriately selected and used. In particular, acrylic pressure-sensitive adhesives are preferably used because they are excellent in optical transparency, exhibit appropriate adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and are also excellent in weather resistance and heat resistance.

  The method for forming the pressure-sensitive adhesive layer is not particularly limited, a method of applying the pressure-sensitive adhesive composition to a release liner, drying and transferring the composition to a glass substrate (transfer method), directly applying the pressure-sensitive adhesive composition to the glass substrate, Drying method (direct printing method) and the like can be mentioned. As the pressure-sensitive adhesive, a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent, and the like can be used as appropriate.

  The preferred thickness of the pressure-sensitive adhesive layer is 5 μm to 100 μm, more preferably 10 μm to 50 μm, and more preferably 15 μm to 35 μm.

<Touch panel>
The transparent conductive film laminate can be suitably applied, for example, as a transparent electrode of an electronic device such as a touch panel of a capacitance type, a resistive type or the like. Further, since the transparent conductive film laminate of the present invention is laminated on a glass substrate, it can be suitably applied as it is to a transparent electrode of an electronic device such as a touch panel.

  In forming the touch panel, the touch panel can be formed using the above-described transparent conductive film laminate. In the present invention, a laminate in which a glass substrate is bonded via a transparent pressure-sensitive adhesive layer is formed on the surface of the transparent conductive film on which the transparent conductive film is not formed. It may be composed of a substrate, or may be a laminate of two or more substrates (for example, laminated with a transparent pressure-sensitive adhesive layer interposed therebetween). As described above, the pressure-sensitive adhesive layer used for bonding the transparent conductive film and the substrate can be used without any particular limitation as long as it has transparency.

  When the above-mentioned transparent conductive film laminate is used for forming a touch panel, the amount and direction of curl after a heating step such as drying can be suppressed, so that the transparent conductive film laminate can be easily transported, and when a touch panel is formed. Excellent handleability. Therefore, it is possible to manufacture a touch panel excellent in transparency and visibility with high productivity. If it is not used for touch panels, it can be used for shielding to shield electromagnetic waves and noise emitted from electronic devices.

<Method for producing transparent conductive film laminate>
The method for producing a transparent conductive film laminate of the present invention includes a step of preparing a transparent conductive film in which an amorphous transparent conductive film is formed on a transparent resin film, and the other one of the transparent conductive film and the transparent conductive film. And a step of heating the transparent conductive film laminate to form a glass substrate on the side of the substrate via an adhesive layer. Examples of the step of heating the transparent conductive film laminate include a step of crystallizing the transparent conductive film and a step of drying the metal wiring formed by the photosensitive metal paste layer. It is preferable to go through such a heating process after forming the transparent conductive film laminate. Accordingly, since the transparent conductive film is designed to curl largely in the concave direction when the transparent conductive film is placed on the lower side, it is possible to suppress the occurrence of curling in the transparent conductive film laminate.

  The transparent conductive film used in the step of preparing the transparent conductive film, a cured resin layer may be formed on the transparent resin film, and then a transparent conductive film may be formed, or the cured resin layer may be formed on the transparent resin film. Obtaining the formed transparent resin laminate, then a transparent conductive film may be formed on the cured resin layer, or a transparent conductive film formed with the cured resin layer and the transparent conductive film on the transparent resin film. May be obtained. As for the above-mentioned optical adjustment layer, a transparent resin laminate formed in advance may be obtained and used.

  In the step of laminating the glass substrate, the pressure-sensitive adhesive layer is formed on the release substrate, the pressure-sensitive adhesive layer is transferred to the glass substrate, and the transparent resin film of the second cured resin layer of the transparent conductive film is not formed. A glass substrate may be laminated on the side via an adhesive layer, or the adhesive layer may be formed directly on the glass substrate. Alternatively, an adhesive layer may be formed on the side of the transparent conductive film opposite to the transparent conductive film, and a glass substrate may be laminated.

  In order to crystallize the components of the transparent conductive film, they are put into a heat-treated step. The heating temperature is preferably, for example, 130 ° C. or lower, more preferably 120 ° C. or lower, and the processing time is, for example, 15 to 180 minutes. Thereafter, the transparent conductive film is etched, and a pattern portion is formed by a pattern. After the transparent conductive film is patterned, the present invention applies the photosensitive conductive paste described above on the transparent resin film or the transparent conductive film, forms a photosensitive metal paste layer, and laminates or closes a photomask. Preferably, the method further includes a step of exposing the photosensitive metal paste layer through the photomask or obtaining metal wiring by screen printing or the like. The drying step is preferably performed at 130 ° C. or lower, and more preferably at 120 ° C. or lower. The heat treatment for crystallization of the transparent conductive film laminate, the subsequent etching step, and the metal wiring step are performed in a single-wafer step because there is a positioning of a photomask or a patterning of the transparent conductive film and the metal wiring and the like. At this time, a step of fixing to the suction plate is necessary for positioning, but since the amount and direction of the curl can be controlled even when dried in the above-mentioned temperature range, the step of fixing to the suction plate may be performed. Becomes possible.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.

[Example 1]
(Preparation of curable resin composition containing spherical particles)
100 parts by weight of an ultraviolet-curable resin composition (trade name "UNIDIC (registered trademark) RS29-120" manufactured by DIC) and acrylic spherical particles having a mode particle diameter of 1.9 μm (trade name manufactured by Soken Chemical Co., Ltd.) Curable resin composition containing spherical particles containing 0.3 parts by weight of “MX-180TA”).

(Formation of cured resin layer)
The prepared curable resin composition containing spherical particles is applied to one surface of a polycycloolefin film having a thickness of 35 μm and a glass transition temperature of 165 ° C. (trade name “ZEONOR (registered trademark)” manufactured by Zeon Corporation). Was formed. Next, the coating layer was irradiated with ultraviolet rays from the side where the coating layer was formed to form a second cured resin layer having a thickness of 1.0 μm. A first cured resin layer was formed on the other surface of the polycycloolefin film in the same manner as described above except that spherical particles were not added so that the thickness became 1.0 μm.

(Formation of optical adjustment layer)
An ultraviolet curable composition containing zirconia particles having a refractive index of 1.62 (trade name “OPSTAR-Z7412” manufactured by JSR Corporation) as an optical adjustment layer on the side of the first cured resin layer of the polycycloolefin film having a cured resin layer formed on both sides. Was applied to form a coating layer. Next, the coating layer was irradiated with ultraviolet rays from the side on which the coating layer was formed to form an optical adjustment layer with a thickness of 100 nm.

(Formation of transparent conductive film)
Next, the polycycloolefin film on which the optical adjustment layer was formed was put into a take-up sputtering apparatus, and an amorphous indium tin oxide layer (composition: SnO) having a thickness of 27 nm was formed on the surface of the optical adjustment layer. ₂ 10 wt%) to form a transparent conductive film. Thus, a transparent conductive film was produced.

(Formation of transparent conductive film laminate)
By ordinary solution polymerization, an acrylic polymer having a weight average molecular weight of 600,000 was obtained with butyl acrylate / acrylic acid = 100/6 (weight ratio). To 100 parts by weight of the acrylic polymer, 6 parts by weight of an epoxy crosslinking agent (trade name “Tetrad C (registered trademark)” manufactured by Mitsubishi Gas Chemical Company) was added to prepare an acrylic pressure-sensitive adhesive. After applying the acrylic pressure-sensitive adhesive obtained as described above on a thin soda glass having a thickness of 0.4 mm and cut into 210 mm × 260 mm (thickness after drying: 20 μm), a transparent conductive film is formed thereon. Thus, a transparent conductive film laminate was produced by bonding the transparent conductive films.

[Example 2]
In Example 1, a 50 μm-thick polycycloolefin film (trade name “ZEONOR (registered trademark)” manufactured by Zeon Corporation) was used as the transparent resin film, and the frequency of the spherical particles contained in the second cured resin layer was the highest. A transparent conductive film and a transparent conductive film laminate were prepared in the same manner as in Example 1 except that a particle having a particle diameter of 0.8 μm was used and the thickness of the second cured resin layer was set to 0.5 μm. The body was made.

[Example 3]
In Example 1, a transparent conductive film and a transparent conductive film were formed in the same manner as in Example 1 except that an optical adjustment layer was formed, an annealing treatment was performed at 150 ° C. for 3 minutes by a roll-to-roll manufacturing method, and then a transparent conductive film was formed. A conductive film laminate was formed.

[Example 4]
In Example 1, a transparent conductive film was produced in the same manner as in Example 1 except that a polycycloolefin film having a thickness of 50 μm (trade name “ZEONOR (registered trademark)” manufactured by Zeon Corporation) was used as the transparent resin film. And a transparent conductive film laminate.

[Example 5]
In Example 3, a transparent conductive film was produced in the same manner as in Example 3, except that a polycycloolefin film having a thickness of 50 μm (trade name “ZEONOR (registered trademark)” manufactured by Zeon Corporation) was used as the transparent resin film. And a transparent conductive film laminate.

[Comparative Example 1]
In Example 1, a 50 μm-thick polycycloolefin film (trade name “ZEONOR (registered trademark)” manufactured by Zeon Corporation) was used as the transparent resin film, and the thickness of the second cured resin layer was 3.0 μm. A transparent conductive film and a transparent conductive film laminate were prepared in the same manner as in Example 1 except that the above procedure was performed.

[Comparative Example 2]
In Example 1, a transparent conductive film was produced in the same manner as in Example 1 except that a 75 μm-thick polycycloolefin film (trade name “ZEONOR (registered trademark)” manufactured by Zeon Corporation) was used as the transparent resin film. And a transparent conductive film laminate.

[Comparative Example 3]
Example 1 was repeated except that a polyester resin (PET) having a thickness of 50 μm and a glass transition temperature of 70 ° C. (trade name “Diafoil (registered trademark)” manufactured by Mitsubishi Plastics) was used as the transparent resin film in Example 1. A transparent conductive film and a transparent conductive film laminate were prepared in the same manner as described above.

<Evaluation>
(1) Measurement of Thickness The thickness was measured with a micro gauge type thickness meter (manufactured by Mitutoyo Corporation) for those having a thickness of 1 μm or more. The thickness of less than 1 μm and the thickness of the optical adjustment layer (100 nm) were measured by an instantaneous multi-photometry system (MCPD2000 manufactured by Otsuka Electronics Co., Ltd.). For a nano-sized thickness such as the thickness of an ITO film or the like, a cross-sectional observation sample is prepared by FB-2000A (manufactured by Hitachi High-Technologies Corporation), and the cross-sectional TEM observation is performed by HF-2000 (manufactured by Hitachi High-Technologies Corporation) Was used to measure the film thickness. Table 1 shows the results of the evaluation.

(2) Measurement of curl value in transparent conductive film The transparent conductive films obtained in Examples and Comparative Examples were cut into a size of 50 cm x 50 cm. After heating at 130 ° C. for 90 minutes with the ITO surface facing down, it was allowed to cool at room temperature (23 ° C.) for 1 hour. Thereafter, the sample was placed on a horizontal surface with the ITO surface facing down, the heights of the four corners from the horizontal plane were measured, and the average value (curl value A) was calculated. Further, the height (curl value B) of the central portion from the horizontal plane was measured. The value (AB) obtained by subtracting the curl value B from the curl value A was calculated as the curl amount. Table 1 shows the results of the evaluation.

(3) Measurement of Curl Value in Transparent Conductive Film Laminate The transparent conductive film laminate obtained in each of Examples and Comparative Examples was cut into a size of 210 mm × 260 mm × 0.4 mm. After heating at 130 ° C. for 90 minutes with the ITO surface facing up, it was allowed to cool at room temperature (23 ° C.) for 1 hour. Thereafter, the sample was placed on a horizontal surface with the ITO surface facing upward, the heights of the four corners from the horizontal plane were measured, and the average value (curl value A) was calculated. Further, the height (curl value B) of the central portion from the horizontal plane was measured. The value (AB) obtained by subtracting the curl value B from the curl value A was calculated as the curl amount. Table 1 shows the results of the evaluation.

(4) Heat Shrinkage in MD and TD The heat shrinkage in the longitudinal direction (MD direction) and the width direction (TD direction) of the transparent conductive film was calculated as follows. Specifically, a transparent conductive film was cut into a width of 100 mm and a length of 100 mm (a test piece), and four corners were scratched with a cross, and four central portions of the cross scratch before heating in the MD and TD directions were measured. The height (mm) was measured by a CNC coordinate measuring machine (LEGEX774 manufactured by Mitutoyo Corporation). Thereafter, the resultant was put into an oven and subjected to a heat treatment (130 ° C., 90 minutes). After cooling at room temperature for one hour, the length (mm) of the four corners after heating in the MD and TD directions at four points is measured again by a CNC coordinate measuring machine, and the measured values are substituted into the following equation. , MD and TD directions were determined. Table 1 shows the results of the evaluation. Heat shrinkage (%) = [[length before heating (mm) −length after heating (mm)] / length before heating (mm)] × 100

(5) Measurement of glass transition temperature (Tg) The glass transition temperature (Tg) was determined in accordance with JIS K7121.

(Results and discussion)
In the transparent conductive films of Examples 1 to 5, the direction of curl generation was a concave direction when the transparent conductive film was placed downward, and the amount of curl generated was as large as 7 to 28 mm. In the figure, the direction of curl generation was a concave direction when the transparent conductive film was faced up, and the curl generation amount was 1.1 to 2.0 mm, and curl generation could be suppressed. In the transparent conductive films of Comparative Examples 1 and 2, the direction of curl generation was a concave direction when the transparent conductive film was placed down, and the amount of curl was as small as 2 to 4 mm. On the other hand, when the transparent conductive film was placed on the upper side, the curl was in the concave direction, and the amount of curl was greatly curled at 2.5 to 4.3 mm. From the above, there is a correlation between the curl amount of the transparent conductive film and the warpage after the transparent conductive film laminate, and when the curl amount of 5 mm or more occurs in the transparent conductive film, the curl amount in the transparent conductive film laminate is It was found that the curl amount of the sample could be reduced. Comparative Example 3 has no problem as the curl value, but cannot be used as a substrate under a polarizing plate because a PET film is used as the substrate and there is a high retardation.

DESCRIPTION OF SYMBOLS 1 Transparent resin film 2 First cured resin layer 3 Transparent conductive film 4 Second cured resin layer 5 Optical adjustment layer 6 Glass substrate 7 Adhesive layer 10 Transparent conductive film

Claims (10)

A transparent conductive film in which a first cured resin layer and a transparent conductive film are formed in this order on one surface side of a transparent resin film, and a second cured resin layer is formed on the other surface side of the transparent resin film. A film,
The transparent resin film is made of an amorphous resin,
Both the thickness of the first cured resin layer and the thickness of the second cured resin layer are 2 μm or less (excluding the case of 2 μm or more),
The difference between the average curl value A at the four corners and the curl value B at the center after the transparent conductive film was cut into 50 cm × 50 cm and heated at 130 ° C. for 90 minutes with the transparent conductive film on the lower surface (A−B) ) Is 5 mm or more. The thickness of the second cured resin layer transparent conductive film according to equal to or thinner claim 1 and the thickness of the first cured resin layer.   The transparent conductive film according to claim 1, further comprising one or more optical adjustment layers between the first cured resin layer and the transparent conductive film.   The transparent conductive film according to claim 1, wherein the second cured resin layer includes a resin and particles.   In the transparent resin film, the amorphous resin is a cycloolefin-based resin, the thickness is 20 to 75 μm, the glass transition temperature is 130 ° C. or more, and the transparent conductive film is heated at 130 ° C. for 90 minutes. The transparent conductive film according to any one of claims 1 to 4, wherein a heat shrinkage after the heat treatment is less than 0.2% in the MD and TD directions.   The transparent conductive material according to claim 1, wherein the optical adjustment layer includes a binder resin and fine particles, has a refractive index of 1.6 to 1.8, and has a thickness of 40 to 150 nm. the film.   The transparent conductive film according to claim 1, wherein the transparent conductive film is made of an indium-tin composite oxide and has a thickness of 10 to 35 nm.   A transparent conductive film laminate in which a glass substrate is laminated via a pressure-sensitive adhesive layer on a surface of the transparent conductive film according to any one of claims 1 to 7 opposite to the transparent conductive film.   9. The curl value A at the four corners and the curl value B at the center after the transparent conductive film laminate according to claim 8 is cut into 210 mm × 260 mm and heated at 130 ° C. for 90 minutes with the transparent conductive film on the upper surface. (A-B) is 2.0 mm or less.   A touch panel obtained by using the transparent conductive film laminate according to claim 8.

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