JP2018073157A - Transparent conductive film and touch panel using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film in which a transparent resin film is unlikely to break in a conveyance process even if the transparent resin film with low tensile breaking strength is used, the transparent conductive film capable of preventing a flaw in the transparent resin film and improving handling properties in the conveyance process, and also to provide a touch panel using the same.SOLUTION: A transparent conductive film 10 includes a second curable resin layer 2'; a transparent resin film 1; a first curable resin layer 2; and a transparent conductive layer 3 in this order. In the transparent conductive film 10, the transparent resin film 1 has a tensile breaking strength of 100 MPa or less. In the transparent conductive film 10, a hardness of the first curable resin layer 2 by an indentation test is higher than the hardness of the second curable resin layer 2' by the indentation test.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transparent conductive film having a second cured resin layer, a transparent resin film, a first cured resin layer, and a transparent conductive layer in this order, and a touch panel using the same.

  Conventionally, so-called conductive glass in which an indium oxide thin film is formed on glass is well known as a transparent conductive member. However, since conductive glass is glass, the conductive glass is inferior in flexibility and workability and may be difficult to apply depending on the application. Therefore, in recent years, transparent conductive films using a plastic film substrate such as polyethylene terephthalate have become widespread because of advantages such as excellent impact resistance and light weight in addition to flexibility and workability.

  As displays equipped with a transparent touch panel on a liquid crystal display element have spread from mobile size to medium to large size, not only the characteristics of liquid crystal display elements have become more sophisticated, but also the transparency of transparent conductive films for touch panels. The demand for improved characteristics is also increasing. In particular, a transparent conductive film using a conventional polyethylene terephthalate has a phase difference of several thousand nm although it depends on the thickness, and may not be used under a polarizing plate.

  Patent Document 1 proposes, for example, a cycloolefin-based resin film or the like as a substrate for a transparent conductive film with a controlled phase difference. However, a base material such as a cycloolefin-based resin film is soft, and the base material alone may be difficult to use in a transport process such as a roll-to-roll process. Therefore, it has been proposed to form a cured resin layer (hard coat layer) on both surfaces of the substrate (for example, Patent Document 2).

JP 2010-162746 A JP 2006-081733 A

  The inventors of the present invention merely provide a cured resin layer made of the same resin composition on both surfaces of the base material to increase the hardness, and in the transport process such as a film forming process and a crystallization annealing process, heat applied and transport tension are applied. Noticed that the film might break easily. Even if the film can be prevented from being broken only by having the same degree of flexibility on both sides as in the cured resin layer described in Patent Document 2, the film is damaged in the transport process such as roll-to-roll. It is easy to enter and handling property may be reduced.

  Therefore, even if a transparent resin film having a low tensile breaking strength is used, the purpose of the present invention is to prevent the transparent resin film from being broken in the transport process and to prevent the transparent resin film from being damaged. An object of the present invention is to provide a transparent conductive film capable of improving the handleability of the film and a touch panel using the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors simply increased the flexibility with the same hardness on both sides for each cured resin layer formed on both sides of the transparent resin film having a low breaking strength. We thought that it was insufficient to satisfy the above-mentioned problems. Therefore, it was thought that the above-mentioned problems could be achieved by adjusting the hardness of each cured resin layer on one side in a well-balanced manner. That is, the hardened resin layer (first cured resin layer) on the surface side on which the transparent conductive layer is formed is increased in hardness, which is a property contrary to flexibility, and the other cured resin layer (second cured resin layer) is formed. It was thought that by making it harder than the cured resin layer), it was possible to prevent the transparent resin film from being damaged in the transporting process such as the film forming process. On the other hand, for the second cured resin layer, by imparting flexibility, which is a characteristic contrary to high hardness, the bending resistance is improved, and the transparent resin in the transporting process such as a film forming process. It was thought that film breakage could be prevented. As described above, the present inventors have found that each of the cured resin layers can be achieved while achieving the above-mentioned objectives by adjusting the hardness in a balanced manner on a single side.

  That is, the present invention is a transparent conductive film having a second cured resin layer, a transparent resin film, a first cured resin layer, and a transparent conductive layer in this order, wherein the transparent resin film is tensile-ruptured. It is a transparent conductive film having a strength of 100 MPa or less and having a hardness by an indentation test of the first cured resin layer larger than a hardness by an indentation test of the second cured resin layer. In addition, unless otherwise indicated, the various physical property values in the present invention are values measured by the methods employed in Examples and the like.

  In general, when a transparent conductive layer is formed on a base material or the transparent conductive layer after film formation is annealed and crystallized, it is often transported by roll-to-roll from the viewpoint of production efficiency. . When the long transparent conductive film meanders due to the influence of the heating roll in the apparatus or the heat trap at the time of sputtering during the roll-to-roll manufacturing method, apply tension to the transparent conductive film, Measures such as correcting meandering are taken. Film breaks are often attributed to this measure. When the tension is applied for the meandering correction measure, the cured resin layer becomes a starting point of breakage and breaks, and the long transparent conductive film breaks due to the cracking. In vacuum film forming methods such as sputtering, it is necessary to form a film in an atmosphere from which impurities such as resin components and water vapor have been removed. Once the transparent conductive film breaks in the vacuum film forming apparatus, It is necessary to open the sputter film formation chamber to the atmosphere and perform from the re-installation of the transparent conductive film to the cleaning, which results in a significant deterioration in productivity. On the other hand, if the cured resin layer is made flexible to prevent film breakage during roll-to-roll conveyance, the substrate is likely to be damaged due to insufficient hardness or the like. In particular, if the surface of the base material on which the transparent conductive layer is formed is damaged, inconvenience occurs when the transparent conductive layer is formed in a later step, which may adversely affect the quality of the transparent conductive layer.

  Therefore, in the present invention, even if a transparent resin film having a low breaking strength is used, the cured resin layer (first cured resin layer) on the side on which the transparent conductive layer is formed has a relatively high hardness, and the other By providing the cured resin layer (second cured resin layer) with flexibility and allowing the functions of both cured resin layers to act in a balanced manner, both film breakage prevention and film damage prevention can be achieved. , Handling can be improved. That is, the relatively hard first cured resin layer mainly functions to prevent the transparent resin film from being damaged, and the relatively soft second cured resin layer improves flexibility and transports. Since it mainly functions to prevent film breakage during the process, the above problems can be solved simultaneously.

  In this invention, it is preferable that the hardness by the indentation test of the said 1st cured resin layer is 0.29 GPa or more, and the hardness by the indentation test of the said 2nd cured resin layer is less than 0.29 GPa. Since each cured resin layer has a hardness in the above range, the balance can be adjusted, so that the line runnability during film formation of the transparent conductive layer can be improved, and the handling property in the annealing process and subsequent processes can be improved. Conveyance is easy and work efficiency can be improved.

  In the present invention, it is preferable that a value obtained by subtracting the hardness by the indentation test of the second cured resin layer from the hardness by the indentation test of the first cured resin layer is greater than 0 GPa and 1.0 GPa or less. Having such a hardness difference is more advantageous in realizing the above-described effects.

  In the present invention, it is preferable that the plastic deformation amount by the indentation test of the first cured resin layer is 50 nm or less, and the plastic deformation amount by the indentation test of the second cured resin layer is larger than 50 nm.

  In the present invention, it is preferable that no film breakage occurs when a 180 ° bending test is performed. Thereby, even if tension and a bending are added at the time of transparent resin film conveyance, a cured resin layer does not break easily, and it can prevent fracture in conveyance by roll to roll more certainly.

  In the present invention, it is preferable to further include one or more optical adjustment layers between the first cured resin layer and the transparent conductive layer. Since the refractive index can be controlled by the optical adjustment layer, when the transparent conductive layer is patterned, the difference in reflectance between the pattern forming portion and the pattern opening can be reduced, and the transparent conductive layer pattern is difficult to see, Visibility can be improved in a display device such as a touch panel.

  The transparent resin film in the present invention is preferably a cycloolefin resin film. A cycloolefin-based resin film generally has a low tensile strength at break and is easily cracked and easily damaged during a transport process such as a roll-to-roll process. However, if the hardness of each cured resin layer can be adjusted as in the present invention and the cycloolefin resin film can be used for roll-to-roll conveyance, the cycloolefin resin film is a low retardation substrate. Even if it is under a board | plate, it can be used and the use as a transparent conductive film can be expanded significantly.

  The touch panel of the present invention preferably includes the transparent conductive film. By using the transparent conductive film, even if a transparent resin film having a low breaking strength is used, the transparent resin film is hardly broken in the transport process, and the transparent resin film can be prevented from being damaged, and the transport process. Can be improved.

It is typical sectional drawing of the transparent conductive film which concerns on one Embodiment of this invention. It is typical sectional drawing of the transparent conductive film which concerns on other embodiment of this invention. It is a typical side view for demonstrating the procedure of a 180 degree bending test.

  Embodiments of the transparent conductive film of the present invention will be described below with reference to the drawings. However, in some or all of the drawings, parts unnecessary for the description are omitted, and there are parts shown enlarged or reduced for easy explanation. The terms indicating the positional relationship such as up and down are merely used for ease of explanation, and are not intended to limit the configuration of the present invention.

<Transparent conductive film>
An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing one embodiment of the transparent conductive film of the present invention. The transparent conductive film 10 has a second cured resin layer 2 ′, a transparent resin film 1, a first cured resin layer 2, and a transparent conductive layer 3 in this order. The first cured resin layer 2 is formed on the first main surface S1 side of the transparent resin film 1, and the second cured resin layer 2 'is on the side opposite to the first main surface S1 of the transparent resin film 1. It is formed on the second main surface S2 side. That is, the first cured resin layer 2 and the second cured resin layer 2 ′ are formed on both surfaces of the transparent resin film 1. The 1st cured resin layer 2 and 2nd cured resin layer 2 'contain what functions as an anti-blocking layer or a hard-coat layer. Although not shown in FIG. 1, if necessary, one or two or more transparent conductive layers are provided on the opposite side of the second cured resin layer 2 ′ to the transparent resin film 1 side. be able to.

  In the transparent conductive film 11 shown in FIG. 2, in addition to the layer configuration of the transparent conductive film 10 shown in FIG. 1, one optical adjustment layer 4 is provided between the first cured resin layer 2 and the transparent conductive layer 3. Furthermore, it is provided. One optical adjustment layer 4 may be two or more optical adjustment layers 4. Although not shown in FIG. 2, if necessary, one or two or more optical adjustment layers may be provided on the opposite side of the second cured resin layer 2 ′ from the transparent resin film 1 side. Can do. A transparent conductive layer can be further provided on the optical adjustment layer.

  Although not shown in FIGS. 1 and 2, from the viewpoint of facilitating roll-to-roll conveyance, a carrier film having an adhesive layer on one surface side of the protective film is transparently conductive via the adhesive layer. Films 10 and 11 can be laminated. In this case, the transparent conductive film laminate can be formed by bonding the surface side of the transparent conductive films 10 and 11 on which the second cured resin layer 2 ′ is formed to the adhesive layer.

(Transparent resin film)
The transparent resin film is not particularly limited as long as the tensile breaking strength is 100 MPa or less, and is preferably 95 MPa or less, more preferably 90 MPa or less, and still more preferably 85 MPa or less from the viewpoint of requiring a cured resin layer on both sides. Although the lower limit value of the tensile strength at break is not particularly limited, it is preferably 10 MPa or more, more preferably 30 MPa or more, from the viewpoint of enabling conveyance by a roll-to-roll manufacturing method.

  As the transparent resin film, various plastic films having transparency are used. For example, as a transparent resin film, a polyester resin film, a cycloolefin resin film, a polycarbonate resin film, an acetate resin film, a polyethersulfone resin film, a polyamide resin film, a polyimide resin film, a polyolefin resin film, Examples include (meth) acrylic resin films, polyvinyl chloride resin films, polyvinylidene chloride resin films, polystyrene resin films, polyvinyl alcohol resin films, polyarylate resin films, polyphenylene sulfide resin films, and the like. From the viewpoints of tensile strength at break, high transparency and low water absorption, preferred are a cycloolefin resin film and a polycarbonate resin film. Of these, a cycloolefin resin film is particularly preferable from the viewpoint of use under a polarizing plate.

  The cycloolefin-based resin film is formed of a cycloolefin-based resin and has characteristics such as high transparency, low phase difference, and low water absorption, but has low tensile strength at break and is in a transport process such as roll-to-roll. It also has the characteristics of being easily broken and easily damaged. By adopting the cycloolefin-based resin film, the optical characteristics of the transparent conductive film can be controlled.

  The cycloolefin resin forming the cycloolefin resin film 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 transparent resin film is preliminarily subjected to etching treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, and undercoating treatment on the surface, and a cured resin layer formed on the transparent resin film or transparent You may make it improve adhesiveness with a conductive layer etc. In addition, before forming the cured resin layer or the transparent conductive layer, the surface of the transparent resin film may be 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 150 μm, more preferably in the range of 25 to 100 μm, and still more preferably in the range of 30 to 80 μm. When the thickness of the transparent resin film is less than the lower limit of the above range, the mechanical strength of the transparent resin film is insufficient, and it may be difficult to continuously form a transparent conductive layer by forming a film base into a roll. is there. On the other hand, if the thickness exceeds the upper limit of the above range, the scratch resistance of the transparent conductive layer and the dot characteristics for touch panels may not be improved.

(Cured resin layer)
The cured resin layer includes a first cured resin layer provided on one surface side of the transparent resin film and a second cured resin layer provided on the other surface side. A transparent resin film with low tensile strength at break has a tendency to be scratched in each process such as formation of a transparent conductive layer, patterning of a transparent conductive layer, or mounting on an electronic device. A first cured resin layer and a second cured resin layer are formed.

  In this invention, the hardness by the indentation test of the 1st cured resin layer is larger than the hardness by the indentation test of the 2nd cured resin layer, It is characterized by the above-mentioned. The lower limit of the hardness by the indentation test of the first cured resin layer is not particularly limited as long as it is larger than the hardness by the indentation test of the second cured resin layer, but is 0.20 GPa or more from the viewpoint of preventing film scratches. It is preferably 0.29 GPa or more, more preferably 0.31 GPa or more. The upper limit of the hardness by the indentation test of the first cured resin layer is not particularly limited, but is preferably 1.0 GPa or less, more preferably 0.8 GPa or less, from the viewpoint of preventing film breakage. More preferably, it is 7 GPa or less.

  On the other hand, the upper limit of the hardness by the indentation test of the second cured resin layer is not particularly limited as long as it is smaller than the hardness by the indentation test of the first cured resin layer from the viewpoint of preventing film breakage, but 0.40 GPa or less Preferably less than 0.30 GPa, and more preferably 0.29 GPa or less. The lower limit of the hardness by the indentation test of the second cured resin layer is not particularly limited, but is preferably 0.10 GPa or more, and more preferably 0.15 GPa or more from the viewpoint of preventing film damage.

  Further, from the viewpoint of achieving both prevention of film breakage and prevention of film damage, a value obtained by subtracting the hardness by the indentation test of the second cured resin layer from the hardness by the indentation test of the first cured resin layer (difference in hardness) = Hardness by indentation test of first cured resin layer-hardness by indentation test of second cured resin layer) is preferably greater than 0 GPa and 1.0 GPa or less, more preferably 0.01 GPa or more and 0.5 GPa or less. Preferably, it is 0.02 GPa or more and 0.4 GPa or less.

  The upper limit of the amount of plastic deformation by the indentation test of the first cured resin layer is not particularly limited, but is preferably smaller than the amount of plastic deformation by the indentation test of the second cured resin layer, from the viewpoint of preventing film damage. 60 nm or less, more preferably 50 nm or less, and still more preferably 40 nm or less. Although the lower limit of the amount of plastic deformation by the indentation test of the first cured resin layer is not particularly limited, it is preferably 1 nm or more from the viewpoint of achieving both prevention of film breakage and prevention of film damage. Is more preferable, and it is still more preferable that it is 10 nm or more.

  On the other hand, the lower limit of the amount of plastic deformation by the indentation test of the second cured resin layer is not particularly limited, but is preferably larger than the amount of plastic deformation by the indentation test of the first cured resin layer. Therefore, it is preferably 40 nm or more, more preferably greater than 45 nm, and still more preferably 50 nm or more. Although there is no restriction | limiting in particular in the upper limit of the amount of plastic deformation by the indentation test of a 2nd cured resin layer, it is preferable that it is 150 nm or less from a viewpoint compatible with film breakage prevention and film damage prevention, and it is 100 nm or less. Is more preferable.

  Further, from the viewpoint of achieving both prevention of film breakage and prevention of film damage, a value obtained by subtracting the amount of plastic deformation due to the indentation test of the second cured resin layer from the amount of plastic deformation due to the indentation test of the first cured resin layer. (Plastic deformation amount = plastic deformation amount by indentation test of first cured resin layer−plastic deformation amount by indentation test of second cured resin layer) is preferably −100 nm to 0 nm, and −50 nm to -5 nm is more preferable, and -40 nm to -10 nm is still more preferable.

  The thicknesses of the first cured resin layer and the second cured resin layer are preferably independently 0.5 μm to 5 μm, more preferably 0.7 μm to 3 μm, and even more preferably 0.8 μm to 2 μm. The thickness of each cured resin layer may be the same or different, but is preferably the same from the viewpoint of work efficiency. By setting the thickness of each cured resin layer within the above range, the scratch resistance and crack resistance of the cured resin layer can be suitably balanced. If the cured resin layer is too thin, the function as a hard coat layer cannot be exhibited, and scratch resistance and crack resistance cannot be obtained. On the other hand, if the cured resin layer is too thick, the flexibility of the entire cured resin layer is lowered and sufficient crack resistance cannot be obtained.

(Resin composition)
The cured resin layer is a layer obtained by curing the resin composition. Here, the cured resin layer has, for example, a component A having 3 or more polymerizable functional groups in the molecule and a weight average molecular weight of 200 to 1,000, and polymerizable functional groups per unit molecular weight in the molecule. It can be set as the layer by which the resin composition containing the component B whose number average is less than the component A and whose weight average molecular weight is larger than 1000 and is 100,000 or less is hardened. In the cured resin 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.

  As the resin composition for forming each cured resin layer, those containing the above specific components A and B are preferable, and those having sufficient strength as a film after forming the cured resin layer and having transparency can be used without particular limitation. . The resin composition forming the cured resin layer may be increased in the amount of the solid component A from the viewpoint of increasing the hardness and preventing the film from being scratched. By carrying out like this, a monomer reaction point can be increased and the hardness of a cured resin layer can fully be raised. In relation to the composition of the second cured resin layer, the composition of the first cured resin layer preferably includes more component A than the second cured resin layer.

  From the viewpoint of imparting flexibility and preventing film breakage, the resin composition forming the second cured resin layer is preferably such that the solid content of component B is greater than the solid content of component A. . In the resin composition forming the second cured resin layer, the solid content of component B is 70% by weight to 90% by weight with respect to the total amount of solid content of component A and solid content of component B. The amount of solid content of component A is preferably 10% to 30% by weight, and preferably 15% to 25% by weight. More preferred. By setting the amount of component A and component B in the resin composition forming the second cured resin layer in the above range, moderate flexibility can be imparted, and in the transport process by the roll-to-roll manufacturing method. Film breakage can be prevented.

  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 that can efficiently form each cured resin 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 (meth) alkyl 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 of each cured resin layer, hardness of each cured resin layer, adhesion to a transparent resin film, and the like, the blending ratio of urethane (meth) acrylate is, for example, 10 to 90 with respect to the total weight of the resin composition. It is the range of weight%, Preferably, it is the range of 20-80 weight%.

  In addition to the above components, the curable resin used in the resin composition for forming the curable resin 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. When a thixotropic agent is used, it is advantageous for the formation of protruding particles on the surface of fine irregularities when the cured resin 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 cured resin 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, silicon oxide (silica particle) particles, hollow nano silica particles, titanium oxide particles, aluminum oxide particles, zinc oxide particles, tin oxide particles, zirconium oxide particles, calcium oxide particles, and other inorganic particles, polymethyl methacrylate, polystyrene, polyurethane Cross-linked or non-cross-linked organic particles or silicone particles made of various polymers such as acrylic resins, acrylic-styrene copolymers, benzoguanamines, melamines, and polycarbonates. 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.

  When the cured resin layer includes particles, the particles contained in the first cured resin layer are preferably inorganic particles from the viewpoint of imparting hardness, and specifically, silica particles are preferable from the viewpoint of increasing hardness. The particles contained in the second cured resin layer may be the same as the particles contained in the first cured resin layer, but may be different particles. From the viewpoint of blocking resistance and imparting flexibility, organic particles are preferable, and specifically, acrylic resin particles are preferable from the viewpoint of refractive index.

(Coating composition)
The coating composition used to form the cured resin 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 cured resin layer increases 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)
Each cured resin layer can be formed by applying the coating composition on a transparent resin film. In addition, a coating composition may be performed directly on a transparent resin film, and can also be performed on the undercoat layer etc. which were formed on the transparent resin film.

  Each cured resin layer is coated with a coating composition on a transparent resin film. If the coating composition contains a solvent, the solvent is dried and cured by application of heat, active energy rays, or both. Is 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 cured resin 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.

(Optical adjustment layer)
An optical adjustment layer can be provided between the first cured resin layer and the transparent conductive layer for the purpose of controlling adhesion and reflection characteristics of the transparent conductive layer. The optical adjustment layer reduces the reflectance difference 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 it difficult to be visually recognized.

The optical adjustment layer may be a single layer or two or more optical adjustment layers. The optical adjustment layer is formed of an inorganic material, an organic material, or a mixture of an inorganic material and an organic material. As a material for forming the optical adjustment layer, NaF, Na ₃ AlF ₆ , LiF, MgF ₂ , CaF _2, SiO ₂ , LaF ₃ , CeF ₃ , Al ₂ O ₃ , TiO ₂ , Ta ₂ O ₅ , ZrO ₂ , Examples thereof include inorganic substances such as ZnO, ZnS, and SiO _x (x is 1.5 or more and less than 2), and organic substances such as acrylic resins, urethane resins, melamine resins, alkyd resins, and siloxane polymers. In particular, it is preferable to use a thermosetting resin made of a mixture of a melamine resin, an alkyd resin, and an organic silane condensate as the organic substance. The optical adjustment layer can be formed using the above materials by a coating method such as a gravure coating method or a bar coating method, a vacuum deposition method, a sputtering method, an ion plating method, or the like.

  The thickness of the optical adjustment layer is preferably 10 nm to 200 nm, more preferably 20 nm to 150 nm, and even 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 have nanoparticles having an average particle diameter of 1 nm to 500 nm. The content of the nanoparticles in the optical adjustment layer is preferably 0.1% by weight to 90% by weight. As described above, the average particle diameter of the nanoparticles used in the optical adjustment layer is preferably in the range of 1 nm to 500 nm, and more preferably 5 nm to 300 nm. Further, the content of the nanoparticles in the optical adjustment layer is more preferably 10% by weight to 80% by weight, and further preferably 20% by weight to 70% by weight. By containing nanoparticles in the optical adjustment layer, the refractive index of the optical adjustment layer itself can be easily adjusted.

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

(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 can be obtained by heat-treating at 30 ° C. for about 30 to 90 minutes to change the amorphous transparent conductive layer into 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 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.

  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.

<Transparent conductive film>
The transparent conductive film of this embodiment can be a transparent conductive film wound body in which a long transparent conductive film is wound in a roll shape. The roll of the long transparent conductive film is a roll of a long transparent resin film, and additional layers such as the cured resin layer, the optical adjustment layer, and the transparent conductive layer described above are used. , Both can be formed by a roll-to-roll process. In forming such a wound body, in consideration of slipperiness and blocking resistance on the surface of the transparent conductive film, a protective film (separator) provided with a weak adhesive layer is bonded, and then rolled. It may be wound.

  The transparent conductive film preferably has no film breakage when subjected to a 180 ° bending test. Also, the transparent conductive film in the state before forming the transparent conductive layer (transparent resin film formed with the first cured resin layer and the second cured resin layer) is a film when the 180 ° bending test is performed. It is preferable that no breakage occurs. Thereby, it is possible to prevent the transparent resin film from being scratched, and even when a tension is applied during transport of the transparent conductive film, the transparent conductive film does not break, and the subsequent process yield can be secured. In the present invention, “rupture” means a state where at least a part of the transparent conductive film is cut over the entire thickness direction.

<Touch panel>
The transparent conductive film can be suitably applied to, for example, a capacitive touch panel or a resistive touch panel.

  In forming the touch panel, another 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. For example, you may form the laminated body by which the transparent base | substrate was bonded together through the transparent adhesive layer on the surface by which the transparent conductive layer of the transparent conductive film is not formed. 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.

<Image display device>
The transparent conductive film of this embodiment can be incorporated in an image display device. The image display device includes an image display element and the touch panel described above. The image display element generally includes a color filter on the viewing side of the image display cell, and a polarizing plate on the opposite side to the viewing side. As the image display cell, a liquid crystal cell, an organic EL cell, or the like can be used.

  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.

(1) 180 ° bending test The sample was measured after the transparent conductive film produced as described below was immersed in 10 wt% hydrochloric acid for 5 min and the transparent conductive layer was etched. That is, a sample having a width of 50 mm and a length of 100 mm was cut out from the COP film on which the first cured resin layer and the second cured resin layer were formed. Next, with the first cured resin layer on the inside, as shown in FIG. 3, the sample S is folded in half, and the ends are bonded together with a commercially available adhesive tape. Placed. A circular weight W (500 g) having a bottom surface of 50 mm in diameter was allowed to stand for 10 seconds on a surface 50 mm wide × 50 mm long obtained by folding in half, and it was confirmed whether or not the film was broken at that time. The case where the film did not break was evaluated as “◯”, the case where the film broke but both ends were not aligned was evaluated as “Δ”, and the case where both ends were aligned was evaluated as “X”. The measured results are shown in Table 1.

(2) Evaluation of scratch resistance After applying a load of 100 g of steel wool (φ25 mm), the prepared first cured resin layer surface was slid 10 times with a length of 10 cm, and then the first cured resin layer. The condition of the surface was evaluated by visual observation for scratching. The case where no scratch was generated was evaluated as “◯”, the case where a thin scratch was confirmed on the entire surface was evaluated as “Δ”, and the case where a significant scratch was confirmed on the entire surface was evaluated as “X”. The measured results are shown in Table 1.

(3) Indentation test (hardness, plastic deformation)
An indentation test was performed under the following conditions, and the hardness [GPa] and the amount of plastic deformation [nm] of the first cured resin layer and the second cured resin layer were measured. The sample was measured after the transparent conductive film produced as described below was immersed in 10 wt% hydrochloric acid for 5 min and the transparent conductive layer was etched.

Apparatus: Hysitron Inc. Nano indenter manufactured Indenter used: Berkovich (triangular pyramid type)
Measuring method: Single indentation measurement Measuring temperature: 25 ° C
Indentation depth setting: 200 nm
Indentation speed: 10 nm / sec
Measurement atmosphere: in air Sample size: 1 cm x 1 cm

(Measuring method)
Using the above apparatus, after holding at room temperature (25 ° C.) for 1 hour, a Barkovic diamond indenter was pushed vertically from the surface of the sample center part to a depth of 200 nm to obtain a first cured resin layer and a second cured resin layer. The hardness [GPa] and the amount of plastic deformation [nm] of the resin layer were measured. Using the analysis software “Triboscan Ver.9.2.12.0”, the indentation depth of the surface (the amount of plastic deformation) from the displacement and load obtained when the indenter was pushed in and the indentation area calculated theoretically ) And hardness. Here, the indentation depth is an index indicating the degree to which the deformed sample surface does not return to the initial state (not elastically recovered) even when the indenter load becomes zero, that is, the amount of plastic deformation of the sample in the loading process. The measured results are shown in Table 1. The calculation formulas for the difference in hardness and the difference in plastic deformation are shown below.

Difference in hardness = Hardness of first cured resin layer−Hardness of second cured resin layer Difference in plastic deformation amount = Plastic deformation amount of first cured resin layer−Plastic deformation amount of second cured resin layer

(4) Measurement of thickness Thickness was measured with a microgauge thickness gauge (Mitutoyo Co., Ltd.) for those having a thickness of 1 μm or more. For those having a thickness of less than 1 μm, an instantaneous multi-photometry system (MCPD2000 manufactured by Otsuka Electronics Co., Ltd.) was used to calculate based on the interference spectrum waveform.

(5) Evaluation of tensile rupture strength After cutting the transparent resin film substrate into a width of 10 mm and a length of 130 mm, using “Autograph-1kNG” (manufactured by Shimadzu Corporation) as a tensile tester, A tensile test was performed at a tensile speed of 300 mm / min, a distance between chucks of 50 mm, and room temperature (23 ° C.) to obtain a stress-strain curve. The stress at the time when the transparent resin film base material was ruptured was determined and used as the tensile rupture strength. The measured results are shown in Table 1.

(6) Measurement of surface resistance value It measured by 4 terminal method according to JISK7194.

(7) Measurement of weight average molecular weight The weight average molecular weight of the component in the prepared resin composition solution was measured by gel permeation chromatography (GPC). The measurement conditions of GPC are as follows.

Measuring instrument: Tosoh product name HLC-8120
GPC column: Tosoh product name G4000H _XL + product name G2000H _XL + product name G1000H _XL (each 7.8 mmφ × 30 cm, total 90 cm)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran Flow rate: 0.8 ml / min Inlet pressure: 6.6 MPa
Standard sample: Polystyrene

(8) Transportability in roll-to-roll When a transparent conductive film was produced as described later, transportability in an actual roll-to-roll manufacturing method was evaluated. That is, as described later, when a transparent conductive layer is formed by a roll-to-roll manufacturing method, “○” is indicated when the transparent conductive film can be transported without breaking, and when the breakage occurs and the film cannot be conveyed. Was evaluated as “×”. The evaluation results are shown in Table 1.

<Example 1>
(Formation of second cured resin layer)
As a material for forming the second cured resin layer, 80 parts by weight of a product name “Unidic ELS-888” manufactured by DIC Corporation and 20 weights of a product name “Unidic RS28-605” manufactured by DIC Corporation. A resin composition solution was prepared by mixing the parts. When the weight average molecular weight of the prepared resin composition solution was confirmed by gel permeation chromatography (GPC), the resin composition solution had a weight average molecular weight of 200 to 1,000 with respect to all resin components. Was 20% by weight, and component B having a weight average molecular weight of 10,000 to 100,000 was contained by 80% by weight.

One of the 40 μm-thick norbornene resin film (manufactured by Nippon Zeon Co., Ltd., trade name “ZEONOR FILM”, hereinafter referred to as “COP film”, tensile rupture strength: 76 MPa) as the base resin film is the prepared resin composition solution. After being applied to the surface of the substrate and dried at 80 ° C. for 1 minute, immediately after irradiation with ultraviolet rays using an ozone type high pressure mercury lamp (UV intensity 180 mW / cm ² , integrated light amount: 230 mJ / cm ² ) The cured resin layer was formed.

(Formation of first cured resin layer)
The surface of the COP film on which the second cured resin layer is formed is coated with an ultraviolet curable resin composition (“Z-850-6L” manufactured by Aika Kogyo Co., Ltd.) at 80 ° C. After drying for 1 minute, ultraviolet irradiation was performed immediately using an ozone type high pressure mercury lamp (UV intensity 160 mW / cm ² , integrated light amount: 230 mJ / cm ² ) to form a first cured resin layer having a thickness of 1.0 μm.

(Deposition of transparent conductive layer)
The COP film having a cured resin layer formed on both surfaces is put into a take-up sputtering apparatus, and a transparent conductive layer made of amorphous indium tin oxide having a thickness of 27 nm is formed on the surface of the first cured resin layer. And a transparent conductive layer was formed. Thereafter, the COP film on which the amorphous layer of indium / tin oxide is formed is put into an air circulation oven by a roll-to-roll method, and subjected to a heat treatment at 130 ° C. for 90 minutes, so that the transparent conductive layer is not formed. A transparent conductive film having a surface resistance value of 100Ω / □ was produced by converting from crystalline to crystalline.

<Example 2>
In Example 1, a transparent conductive film was produced in the same manner as in Example 1 except that a resin composition (manufactured by JSR Corporation, “KZ6506”) was used as the resin composition of the first cured resin layer. did.

<Example 3>
In Example 1, a transparent conductive film was produced in the same manner as in Example 1 except that a resin composition (manufactured by JSR Corporation, “Z7503”) was used as the resin composition of the first cured resin layer. did.

<Comparative Example 1>
In Example 1, the transparent conductive film was the same as in Example 1 except that the resin composition of the second cured resin layer was the same as the resin composition of the first cured resin layer. Was made.

<Comparative example 2>
In Example 1, a transparent conductive film was prepared in the same manner as in Example 1 except that the resin compositions shown in Table 1 were used as the resin compositions of the first cured resin layer and the second cured resin layer. Produced.

(Results and discussion)
First, the relationship between the transparent resin film substrate and the breaking strength was examined. As a result, the tensile strength at break of each substrate was 76 MPa for the cycloolefin resin film (COP film), 98 MPa for the polycarbonate resin film (PC film), and 217 MPa for the polyester resin film (PET film). When a hard base material having a high tensile breaking strength such as a PET film is used, it is often unnecessary to form a cured resin layer on both surfaces of the base material. On the other hand, when a soft base material having a low tensile breaking strength such as a COP film or PC film is used, it is necessary to form a cured resin layer on both surfaces of the base material. Adjusting is considered particularly useful in the present invention.

  Next, Table 1 shows the obtained evaluation results. As shown in Table 1, as in Examples 1 and 2, when the relationship of hardness is the second cured resin layer <the first cured resin layer, no fracture occurred in the 180 ° bending test, and the scratch resistance. In the evaluation, no scratch was generated, and good results were obtained. Further, even when used in an actual machine, the transparent conductive film could be transported by a roll-to-roll manufacturing method without causing breakage. By making the hardness of the first cured resin layer larger than the hardness of the second cured resin layer, the second cured resin layer having flexibility can prevent film breakage and also has a high curability. It is considered that scratches can be prevented by the cured resin layer. Thereby, when conveying a film with a roll to roll manufacturing method, while being able to convey without producing a film fracture | rupture, the damage to a film can be prevented and handling property can be improved. Further, as in the case of the transparent conductive film of Example 3, even if the hardness relationship is the second cured resin layer <the first cured resin layer, if the hardness of the first cured resin layer is too large, There is a possibility of breaking in the 180 ° bending test.

  On the other hand, as in Comparative Example 1, when the relationship of hardness was the second cured resin layer = the first cured resin layer, the fracture was not caused in the 180 ° bending test, but the scratch resistance was evaluated in the scratch resistance evaluation. As a result, good results were not obtained. This is considered due to the fact that the hardness of the first cured resin layer is too flexible. Further, as in Comparative Example 2, when the hardness relationship is the second cured resin layer = the first cured resin layer, but the hardness is relatively large, the film breaks when the 180 ° bending test is broken. It was not possible to achieve both prevention of film damage. Furthermore, regarding the transportability in roll-to-roll, in Comparative Example 1, the transparent conductive film was not broken and could be transported by the roll-to-roll manufacturing method, but in Comparative Example 2, the transparent conductive film was broken. Therefore, it could not be conveyed by the roll-to-roll manufacturing method. In addition, as a cause of breakage in the actual machine test, film wrinkles are generated after passing through the heating roll, and it is estimated that local bending occurs in the film and breakage occurs.

DESCRIPTION OF SYMBOLS 1 Transparent resin film 2 1st cured resin layer 2 '2nd cured resin layer 3 Transparent conductive layer 4 Optical adjustment layer 10, 11 Transparent conductive film S1 1st main surface (transparent resin film) S2 (Transparent resin film) 2) Main surface S Sample B Base W Weight

Claims (8)

A transparent conductive film having a second cured resin layer, a transparent resin film, a first cured resin layer, and a transparent conductive layer in this order,
The tensile breaking strength of the transparent resin film is 100 MPa or less,
The transparent conductive film whose hardness by the indentation test of a said 1st cured resin layer is larger than the hardness by the indentation test of a said 2nd cured resin layer.   The transparent conductivity according to claim 1, wherein the hardness of the first cured resin layer by an indentation test is 0.29 GPa or more, and the hardness of the second cured resin layer by an indentation test is less than 0.29 GPa. the film.   The transparent conductive material according to claim 1 or 2, wherein an amount of plastic deformation by an indentation test of the first cured resin layer is 50 nm or less, and an amount of plastic deformation by an indentation test of the second cured resin layer is larger than 50 nm. Sex film.   The value obtained by subtracting the hardness by the indentation test of the second cured resin layer from the hardness by the indentation test of the first cured resin layer is greater than 0 GPa and 1.0 GPa or less. The transparent conductive film as described in the item.   The transparent conductive film according to any one of claims 1 to 4, wherein film breakage does not occur when a 180 ° bending test is performed.   The transparent conductive film according to any one of claims 1 to 5, further comprising one or more optical adjustment layers between the first cured resin layer and the transparent conductive layer.   The transparent conductive film according to claim 1, wherein the transparent resin film is a cycloolefin-based resin film. The touch panel containing the transparent conductive film of any one of Claims 1-7.

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