TWI633563B - Transparent conductive film with carrier film and touch panel using the same - Google Patents

Abstract

The present invention provides a transparent conductive film with a carrier film and a touch panel using the same, which prevents the resistance value of the transparent conductive film from being abnormal by controlling the water content of the protective film of the transparent conductive film with the carrier film. Further, the adhesion between the transparent conductive film and the substrate is improved to prevent the film from peeling off. A transparent conductive film with a carrier film according to the present invention, comprising: a transparent conductive film comprising a transparent resin film and a transparent conductive film; and a carrier film comprising: the transparent conductive film disposed on the transparent conductive film; The adhesive layer and the protective film on the surface side; the transparent conductive film is an indium tin composite oxide, and the water content of the protective film is 1.0 × 10 ^-3 g or less per 10 cm × 10 cm.

Description

Transparent conductive film with carrier film and touch panel using the same

The present invention relates to a transparent conductive film containing a carrier film of a transparent conductive film and a carrier film, and a touch panel using the same, which is a useful technique for preventing abnormal resistance value and film peeling.

Background Art In the field of touch panels and the like, in recent years, the thickness thereof has been increasingly pursued, and the thickness of the transparent conductive film itself has been desired. Examples of a general touch panel include a resistive film method and a static capacitance method. In recent years, most of the touch panels have adopted a static capacitance method, and polyethylene terephthalate (PET) has been widely used as a base film of a transparent conductive film because of flexibility, workability, and impact resistance. Excellent, lightweight and so on.

With the thinning of the base film, in order to ensure the rationality of the base film in the manufacturing step, the necessity of the surface protective film bonded via the adhesive layer on the side opposite to the transparent conductive layer of the base film is improved. . In general, the surface protective film is the same as the substrate film, and PET is widely used.

Patent Document 1 discloses an amorphous transparent conductive laminated body which is laminated on a transparent conductive film made of PET as a base material on the surface side where the transparent conductive layer is not formed, and is laminated with PET by using an adhesive layer. Protective film for the substrate.

On the other hand, ITO (Indium Tin Composite Oxide) for a capacitive touch panel electrode requires a low surface resistance value in order to form a high-sensitivity and high-resolution pattern. Patent Document 2 discloses a laminate in which a protective film is laminated on a transparent conductive film made of PET as a film substrate. When ITO is used as the transparent conductor layer, the ITO is crystallized by heating to reduce the resistance. However, in Patent Document 2, the indium composite oxide having a large proportion of the oxide of the tetravalent metal element is further deposited. An indium-based composite oxide having a small proportion of oxides of indium oxide or a tetravalent metal element is deposited to lower the resistance of the ITO film.

PRIOR ART DOCUMENT PATENT DOCUMENT Patent Document 1: WO2008-108255 Patent Document 2: JP-A-2012-112031

Summary of invention

Problem to be Solved by the Invention However, since the PET film contains a large amount of water in the substrate itself, it is affected by the moisture, and the crystallization of the transparent conductive film cannot be sufficiently performed. In other words, the crystal growth rate of the transparent conductive film is inhibited by the influence of the moisture, and not only the crystallization rate is slowed, but also the resistance value is increased or fluctuated, and the resistance value of the transparent conductive film is abnormal, or the adhesion between the transparent conductive film and the substrate is caused. Lowering, film peeling occurs at the interface. The inventors of the present invention have found that the influence of the moisture content of the film is not only derived from the substrate of the transparent conductive film, but also from the protective film in the form in which the transparent conductive film is combined with the protective film.

Accordingly, an object of the present invention is to provide a transparent conductive film with a carrier film and a touch panel using the same, which can prevent a transparent conductive film by controlling the water content of the protective film of the transparent conductive film with the carrier film. The resistance value is abnormal, and the adhesion between the transparent conductive film and the substrate is improved to prevent the film from peeling off.

The present inventors have made efforts to solve the above problems, and as a result, have found that the above object can be attained by the following constitution, and the present invention has been completed.

That is, the transparent conductive film with a carrier film of the present invention includes a transparent conductive film including a transparent resin film and a transparent conductive film, and a carrier film including the transparent layer formed on the transparent conductive film. An adhesive layer and a protective film on the surface side of the resin film; the transparent conductive film is an indium tin composite oxide, and the water content of the protective film is 1.0 × 10 ^-3 g or less per 10 cm × 10 cm. Further, various physical properties in the present invention are values measured by the methods employed in the examples and the like, unless otherwise specified.

According to the transparent conductive film with a carrier film of the present invention, the resistance value of the transparent conductive film can be prevented from being abnormal, and the adhesion between the transparent conductive film and the substrate can be improved to prevent film peeling. Although the mechanism of abnormal resistance value and membrane peeling is not clear, the reason is considered as follows. Regarding the abnormality of the resistance value, it is considered to be particularly affected by the moisture content of the protective film. The reason for this is that the degassing of the substrate is performed by the annealing and degassing processes before the sputtering of the transparent conductive film. Therefore, the transparent resin film is formed in a state in which moisture and outgassing are small, and the film is bonded in the subsequent step. The moisture of the protective film directly affects the finished transparent conductive film. Further, when the protective film contains a large amount of water, not only the crystallization of the transparent conductive film is not sufficiently performed, the desired resistance value is not obtained, and the unevenness of the in-plane resistance value is deteriorated. The reason for this is that the moisture adsorbed by the substrate or the gas generated when the plasma or the like is contacted acts as an impurity, and the crystal growth is inhibited. The film peeling (adhesiveness) is presumed to be an oxidation reaction at the interface between the transparent conductive film and the substrate (such as a transparent resin film), whereby localized crystal deformation (lattice constant change) occurs in the vicinity of the interface, and thus the adhesion is improved. Reduce and cause film peeling. In other words, it is considered that the interface between the transparent conductive film and the substrate is oxidized by the influence of moisture, so that the adhesion is lowered and the film is peeled off.

The transparent resin film of the present invention preferably has a first cured resin layer provided on the surface side of the transparent conductive film, and a second cured resin layer provided on a surface opposite to the transparent conductive film. Since the cured resin layer is formed on both surfaces of the transparent resin film, it is less likely to be damaged in each step of forming a transparent conductive film, patterning, or mounting on an electronic device.

The transparent conductive film with a carrier film of the present invention is preferably provided with 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 ITO film is patterned, the difference in reflectance between the pattern forming portion and the pattern opening portion can be reduced, and the transparent conductive film pattern is not easily seen, and is displayed in a display device such as a touch panel. The visibility becomes good.

The thickness of the protective film in the present invention is preferably from 1 μm to 150 μm. The thinner the thickness of the protective film, the more the water content of the protective film can be suppressed, and the crystallization of the transparent conductive film can be sufficiently performed. Therefore, the resistance value of the transparent conductive film can be more reliably prevented, and the transparent conductive film can be further improved. The adhesion of the substrate prevents the film from peeling off. Moreover, by setting it as the said range, the conveyability of the roll-to-roll method can be improved.

The protective film in the present invention is preferably composed of a cycloolefin resin or a polycarbonate resin. By using a resin having a low water content, the water content of the protective film can be further controlled, and the crystallization of the transparent conductive film can be sufficiently performed, so that the resistance value of the transparent conductive film can be more reliably prevented, and the resistance can be further improved. The adhesion between the transparent conductive film and the substrate prevents the film from peeling off.

The moisture content of the protective film in the present invention is preferably 0.50% by weight or less. Therefore, since the protective film having a low moisture content can be used, the water content of the protective film can be further controlled, and the crystallization of the transparent conductive film can be sufficiently performed, so that the resistance value of the transparent conductive film can be more reliably prevented, and The adhesion between the transparent conductive film and the substrate is improved to prevent the film from peeling off.

In the present invention, it is preferable that the protective film further has a conductive layer on the side opposite to the surface on which the adhesive layer is formed. Thereby, it is antistatic and can suppress the influence of unnecessary electric power.

The touch panel of the present invention preferably comprises the above transparent conductive film with a carrier film. Thereby, the resistance value of the transparent conductive film can be more reliably prevented, and the adhesion between the transparent conductive film and the substrate can be improved, and the film can be prevented from peeling off, so that a stable high-sensitivity and high-resolution pattern can be formed. The visibility of the display device of the touch panel is improved.

(Embodiment for Carrying Out the Invention) An embodiment of a transparent conductive film with a carrier film of the present invention will be described below with reference to the drawings. In addition, in some parts or all figures, the part which does not need to be described is abbreviate|omitted, and it is the figure which shows the enlargement, a The terms indicating the positional relationship between the top and bottom are used for ease of explanation and are not intended to limit the configuration of the present invention.

<Transparent Conductive Film with Carrier Film> Fig. 1 is a cross-sectional view showing an embodiment of a transparent conductive film of the carrier film of the present invention, and Fig. 2 is a carrier film according to another embodiment of the present invention. A schematic cross-sectional view of a transparent conductive film. As shown in FIG. 1, the transparent conductive film with a carrier film of the present invention includes a transparent conductive film 20 including a transparent resin film 3 and a transparent conductive film 4, and a carrier film 10 including a transparent conductive film 20. The adhesive layer 2 and the protective film 1 on the surface side of the transparent resin film 3 are formed. Further, a conductive layer may be further provided on the side opposite to the surface on which the pressure-sensitive adhesive layer 2 is formed on the protective film 1.

Further, as shown in FIG. 2, the transparent resin film 3 may have a first cured resin layer 6 provided on the surface side of the transparent conductive film 4 and a second cured resin provided on the surface opposite to the transparent conductive film 4. Layer 5, but may have only one of the hardened resin layers on one side. Further, the first cured resin layer 6 and the second cured resin layer 5 include a layer functioning as an anti-adhesion layer or a hard coat layer. Further, one layer of the optical adjustment layer 7 may be provided between the first cured resin layer 6 and the transparent conductive film 4, or two or more optical adjustment layers 7 may be provided. In addition, in FIG. 2, the transparent conductive film 20 has the second cured resin layer 5, the transparent resin film 3, the first cured resin layer 6, the optical adjustment layer 7, and the transparent conductive film 4, but may be, for example, The transparent conductive film 20 having the second cured resin layer 5, the transparent resin film 3, the first cured resin layer 6, and the transparent conductive film 4, or the transparent resin film 3, the optical adjustment layer 7, and the transparent conductive layer in this order The transparent conductive film 20 of the film 4 may be any combination.

The resistance value (surface resistance value) of the transparent conductive film with a carrier film from the amorphous crystal to the crystal is preferably 100 to 130 Ω/□, preferably 100 to 120 Ω/□, more preferably 100~110Ω/□. Thereby, a stable high-sensitivity, high-resolution pattern can be formed.

The standard deviation of the resistance value (surface resistance value) at the time of completion of crystallization from amorphous to crystalline crystal of the transparent conductive film with a carrier film is preferably 30 Ω/□ or less, preferably 20 Ω/□ or less, more preferably It is 10 Ω/□ or less. Thereby, a stable high-sensitivity, high-resolution pattern can be formed.

<Transparent Conductive Film> The transparent conductive film has a transparent resin film and a transparent conductive film. The transparent conductive film may have a transparent resin film having a first cured resin layer provided on the surface side of the transparent conductive film and a second cured resin provided on the surface opposite to the transparent conductive film. Floor. The transparent conductive film may further include one or more optical adjustment layers between the first cured resin layer and the transparent conductive film.

The thickness of the transparent conductive film is preferably in the range of 20 to 150 μm, preferably in the range of 25 to 100 μm, more preferably in the range of 30 to 80 μm. When the thickness of the transparent conductive film is less than the lower limit of the above range, the mechanical strength is insufficient, and the operation of continuously forming the cured resin layer or the transparent conductive film in the form of a roll of the film substrate becomes difficult. On the other hand, when the thickness exceeds the upper limit of the above range, there is a case where the scratch resistance of the transparent conductive film or the like or the click characteristics for the touch panel cannot be improved.

(Transparent Resin Film) The transparent resin film is not particularly limited as long as it is transparent in the visible light region, and various plastic films having transparency can be used. Examples of the material thereof include a polyester resin, a cycloolefin resin, a polycarbonate resin, an acetate resin, a polyether oxime resin, a polyamide resin, a polyimide resin, and a polyolefin. Resin, (meth)acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyacrylic resin, polyarylate resin, polyphenylene A sulfur-based resin or the like. From the viewpoint of improving visibility, a polyester resin, a cycloolefin resin, or a polycarbonate resin is preferable, but high transparency, low water absorbability, moisture barrier property, thermal stability, and the like are preferable. From the viewpoint of the squareness and the like, a cycloolefin resin or a polycarbonate resin which is an amorphous resin is particularly preferable.

The polyester resin is preferably a polyethylene terephthalate resin or a polyethylene naphthalate resin in terms of mechanical properties or heat resistance.

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

The cyclic olefin is a polycyclic cyclic olefin and a monocyclic cyclic olefin. Examples of the polycyclic cyclic olefin include norbornene, methylnordecene, dimethyl norbornene, ethyl norbornene, ethylidene butene, butyl norbornene, and Cyclopentadiene, dihydrodicyclopentadiene, methyl dicyclopentadiene, dimethyl dicyclopentadiene, tetracyclododecene, methyltetracyclododecene, dimethylcyclotetra- Decadiene, tricyclopentadiene, tetracyclopentadiene, and the like. Further, examples of the monocyclic cyclic olefin include cyclobutene, cyclopentene, cyclooctene, cyclooctadiene, cyclooctanetriene, and cyclododecatriene.

The cycloolefin-based resin can be obtained as a commercially available product, and examples thereof include "ZEONOR" manufactured by Japan ZEON Co., Ltd., "ARTON" manufactured by JSR Corporation, "TOPAS" manufactured by Polyplastics Co., Ltd., and "APEL" manufactured by Mitsui Chemicals Co., Ltd., and the like.

The polycarbonate resin is not particularly limited, and examples thereof include an aliphatic polycarbonate, an aromatic polycarbonate, and an aliphatic-aromatic polycarbonate. Specific examples thereof include bisphenol A polycarbonate, branched bisphenol A polycarbonate, foamed polycarbonate, copolycarbonate, and block copolymer which are polycarbonates (PC) using bisphenols. Carbonate, polyester carbonate, polyphosphonate carbonate, bisallyl diethylene glycol carbonate (CR-39), and the like. Also included in the polycarbonate resin are bisphenol A polycarbonate blends, polyester blends, ABS blends, polyolefin blends, styrene-maleic anhydride copolymer blends, and the like. The ingredients are blended. As a commercial item of the polycarbonate resin, "OPCON" manufactured by Hohhot Co., Ltd., "PANLITE" manufactured by Teijin Co., Ltd., "YUPILON (polycarbonate containing ultraviolet absorber)" manufactured by Mitsubishi Gas Chemical Co., Ltd., and the like are exemplified.

In the transparent resin film, the surface may be subjected to an etching treatment such as sputtering, corona discharge, fire spraying, ultraviolet irradiation, electron beam irradiation, chemical change, oxidation, or a primer coating treatment to harden the surface formed on the transparent resin film. The adhesion between the resin layer or the transparent conductive film is improved. Further, before the formation of the cured resin layer or the transparent conductive film, the surface of the transparent resin film may be dusted and cleaned by solvent washing or ultrasonic cleaning as necessary.

The thickness of the transparent resin film is preferably in the range of 20 to 150 μm, preferably from the viewpoint of producing a transparent conductive film having high transparency and excellent appearance quality, and improving the ease of transport in the roll-to-roll method. It is in the range of 25 to 100 μm, 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 is insufficient, and the operation of continuously forming the cured resin layer or the transparent conductive film in the form of a roll of the film substrate becomes difficult. On the other hand, when the thickness exceeds the upper limit of the above range, there is a case where the scratch resistance of the transparent conductive film or the like or the click characteristics for the touch panel cannot be improved.

The water content of the transparent resin film is preferably 5.0 × 10 ^-3 g or less per 10 cm × 10 cm, preferably 3.0 × 10 ^-3 g or less per 10 cm × 10 cm, more preferably 1.0 × 10 ^-3 g or less per 10 cm × 10 cm. In this way, since the water content of the transparent resin film can be further controlled and the crystallization of the transparent conductive film is sufficiently performed, the resistance value of the transparent conductive film can be more reliably prevented, and the adhesion between the transparent conductive film and the substrate can be further improved. To prevent film peeling.

The moisture content of the transparent resin film is preferably 0.50% by weight or less, preferably 0.40% by weight or less, more preferably 0.30% by weight or less.

(hardened resin layer)

The cured resin layer includes a first cured resin layer provided on the surface side of the transparent conductive film of the transparent resin film, and a second cured resin layer provided on the opposite side of the transparent conductive film. When the transparent resin film is weak and easily damaged, it is easily damaged in the steps of patterning the transparent conductive film and the transparent conductive film or mounting it on the electronic device. Therefore, it is preferable to form the surface of the transparent resin film as described above. 1 hardened resin layer and 2nd hardened resin layer.

The hardened resin layer is a layer obtained by hardening a hardening type resin or the like. The resin to be used is not particularly limited, and the film obtained by forming the cured resin layer may have sufficient strength and transparency, and examples thereof include a thermosetting resin, an ultraviolet curable resin, and an electron beam curing resin. Two-liquid mixed resin and the like. Among them, it is preferable to form an ultraviolet curable resin which can efficiently form a cured resin layer by a simple processing operation by a hardening treatment by ultraviolet irradiation.

Examples of the ultraviolet curable resin include various resins such as polyester-based, acrylic-based, urethane-based, guanamine-based, polyfluorene-based, and epoxy-based resins, and include ultraviolet-curable monomers and oligomers. Polymers, etc. The ultraviolet curable resin to be preferably used is an acrylic resin, an epoxy resin or an urethane resin, and more preferably an acrylic resin or an urethane resin.

The hardened resin layer may also contain particles. By arranging the particles in the cured resin layer, ridges can be formed on the surface of the cured resin layer, and the transparent conductive film can be appropriately provided with anti-adhesion.

As the particles, any of metal oxides, glass, plastics, and the like having transparency can be used without particular limitation. For example, inorganic particles such as cerium oxide, aluminum oxide, titanium oxide, zirconium oxide, and calcium oxide, and copolymerization of polymethyl methacrylate, polystyrene, polyurethane, acrylic resin, and acrylic acid-styrene may be mentioned. Crosslinked or uncrosslinked organic particles or polyoxynized particles formed by various polymers such as acrylic acid-styrene resin, benzomelamine, melamine, and polycarbonate. The particles may be used singly or in combination of two or more kinds, but organic particles are preferred. From the viewpoint of the refractive index, the organic particles are preferably an acrylic resin or an acrylic-styrene resin.

The diameter of the particles is appropriately set in consideration of the relationship between the protrusion degree of the cured resin layer or the thickness of the flat region other than the ridge, and is not particularly limited. In addition, from the viewpoint of sufficiently imparting anti-adhesion to the transparent conductive film and sufficiently suppressing an increase in haze, the diameter of the particles is preferably 0.1 to 5 μm, preferably 0.5 to 4 μm. In the present specification, the "diameter" refers to a particle diameter indicating the maximum value of the particle distribution, and a flow type particle image analyzer (product name "FPTA-3000S" manufactured by Sysmex Corporation) is used under specific conditions ( Sheath solution: ethyl acetate, measurement mode: HPF measurement, measurement method: total count) was determined by measurement. For the measurement sample, a sample obtained by diluting the particles with ethyl acetate to 1.0% by weight and uniformly dispersing the mixture using an ultrasonic cleaner was used.

The content of the particles is preferably 0.05 to 1.0 part by weight, preferably 0.1 to 0.5 part by weight, more preferably 0.1 to 0.2 part by weight, per 100 parts by weight of the solid content of the resin composition. If the content of the particles in the cured resin layer is small, it tends to be difficult to form a ridge which is sufficient to impart anti-adhesion and smoothness to the surface of the cured resin layer. 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 is lowered. In addition, when the content of the particles is too large, there are cases where lines are formed when the cured resin layer is formed (at the time of application of the solution), and the visibility or the electrical properties of the transparent conductive film are not uniform.

The cured resin layer can be obtained by coating a resin composition containing each of the curable resin and optionally added particles, a crosslinking agent, a starter, a sensitizer, or the like on the transparent resin film. When the resin composition contains a solvent, the solvent is dried and hardened by applying heat, an active energy ray or both. As the heat, an well-known mechanism such as an air circulation type oven or an IR heater can be used, but the method is not limited thereto. Examples of the active energy ray include ultraviolet rays, electron beams, gamma rays, and the like, but are not particularly limited.

The hardened resin layer can be formed by a coating method such as a wet coating method, a gravure coating method, or a bar coating method, a vacuum deposition method, a sputtering method, an ion plating method, or the like, using the above materials. For example, when indium oxide (ITO) containing tin oxide is formed as a transparent conductive film, the surface of the cured resin layer as the underlayer is smooth, and the crystallization time of the transparent conductive film can be shortened. From this point of view, the cured resin layer is preferably formed by a wet coating method.

The thickness of the cured resin layer is preferably from 0.5 μm to 5 μm, preferably from 0.7 μm to 3 μm, and most preferably from 0.8 μm to 2 μm. When the thickness of the cured resin layer is within the above range, it is possible to prevent damage or prevent film wrinkles in hardening and shrinkage of the cured resin layer, and it is possible to prevent deterioration of visibility of a touch panel or the like.

(Optical Adjustment Layer) One or more optical adjustment layers may be further included between the first cured resin layer and the transparent conductive film. Further, when the first cured resin layer is not formed, one or more optical adjustment layers may be included between the transparent resin film and the transparent conductive film. The optical adjustment layer is used to increase the transmittance of the transparent conductive film or to reduce the difference in transmittance and the reflectance between the pattern portion where the pattern remains and the opening portion where the pattern does not remain when the transparent conductive film is patterned. A transparent conductive film excellent in visibility can be obtained.

The optical adjustment layer preferably contains a binder resin and fine particles. Examples of the binder resin included in the optical adjustment layer include an acrylic resin, an urethane resin, a melamine resin, an alkyd resin, a siloxane polymer, an organic decane condensate, and the like to contain acrylic acid. A resin-based ultraviolet curable resin is preferred.

The refractive index of the optical adjustment layer is preferably 1.6 to 1.8, preferably 1.61 to 1.78, more preferably 1.62 to 1.75. Thereby, the difference in transmittance and the difference in reflectance can be reduced, and a transparent conductive film excellent in visibility can be obtained.

The optical adjustment layer may also have fine particles having an average particle diameter of from 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, preferably 5 nm to 300 nm as described above. Further, the content of the fine particles in the optical adjustment layer is preferably from 10% by weight to 80% by weight, more preferably from 20% by weight to 70% by weight. The refractive index adjustment of the optical adjustment layer itself can be easily performed by containing fine particles in the optical adjustment layer.

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

The optical adjustment layer may contain other inorganic substances. Examples of the inorganic substance include 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), and LaF ₃ ( 1.55), CeF (1.63), etc. (the value in parentheses indicates the refractive index).

The optical adjustment layer can be formed by a coating method such as a wet coating method, a gravure coating method, or a bar coating method, a vacuum deposition method, a sputtering method, an ion plating method, or the like, using the above materials. For example, when indium oxide (ITO) containing tin oxide is formed as a transparent conductive film, the surface of the optical adjustment layer as the underlayer is smooth, and the crystallization time of the transparent conductive layer can be shortened. From this point of view, the optical adjustment layer is preferably formed by a wet coating method.

The thickness of the optical adjustment layer is preferably from 40 nm to 150 nm, preferably from 50 nm to 130 nm, 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 too large, the transparency of the transparent conductive film is lowered or cracking tends to occur.

(Transparent Conductive Film) The transparent conductive film may be provided on the transparent resin film, but is preferably provided on the first cured resin layer or the optical adjustment 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 may be suitably selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, cerium, zirconium, magnesium, aluminum, gold, silver, copper, and palladium. a metal oxide of at least one metal of the group consisting of tungsten. Further, in the metal oxide, a metal atom represented by the above group may be further contained as needed. For example, indium tin composite oxide (ITO), antimony-containing tin oxide (ATO), or the like is preferably used.

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

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

The transparent conductive film may be crystallized by heat annealing treatment (for example, at 80 to 150 ° C for about 10 to 90 minutes in an atmosphere). By crystallizing the transparent conductive film, in addition to lowering the resistance of the transparent conductive film, transparency and durability are also improved. The method of converting the amorphous transparent conductive film into a crystalline substance is not particularly limited, and an air circulating oven, an IR heater, or the like can be used.

The definition of "crystalline" is a transparent conductive film in which a transparent conductive film is formed on a transparent resin film, and immersed in hydrochloric acid at a concentration of 5 wt% for 15 minutes at 20 ° C, and then washed with water and dried to measure 15 mm. The resistance between the terminals was measured. When the resistance between the terminals did not exceed 10 kΩ, the conversion of the ITO film toward the crystal quality was completed. Further, the surface resistance value can be measured by a four-terminal method in accordance with JIS K7194.

Further, the transparent conductive film may be patterned by etching or the like. The patterning of the transparent conductive film can be carried out using a technique known from the conventional photolithography method. As the etching solution, an acid is preferably used. Examples of the acid include inorganic acids such as hydrogen chloride, hydrogen bromide, sulfuric acid, nitric acid, and phosphoric acid; organic acids such as acetic acid; and mixtures thereof; and aqueous solutions thereof. For example, in a transparent conductive film used in a capacitive touch panel or a matrix resistive touch panel, the transparent conductive film should be patterned into stripes. Further, when the transparent conductive film is patterned by etching, if the crystallization of the transparent conductive film is performed first, it may be difficult to pattern by etching. Therefore, the annealing treatment of the transparent conductive film is preferably performed after patterning the transparent conductive film.

<Carrier film> The carrier film includes an adhesive layer and a protective film which are disposed on the surface side of the transparent conductive film on which the transparent resin film is formed, and the transparent conductive film and the carrier film are bonded to each other to form a transparent conductive film with a carrier film. film. When the carrier film is peeled off from the transparent conductive film of the carrier film, the adhesive layer may be peeled off together with the protective film, or only the protective film may be peeled off.

(Protective film) The protective film is peeled off and discarded when it is laminated with another film such as a wave plate or a polarizing plate. However, it is considered that the roll is taken up by a roll, etc., and the water content is used. As a material for forming a protective film, for example, The material of the aforementioned transparent resin film is the same. From the viewpoint of improving visibility, a polyester resin, a cycloolefin resin, or a polycarbonate resin is preferable, but high transparency, low water absorbability, moisture barrier property, thermal stability, and the like are preferable. From the viewpoint of the squareness and the like, a cycloolefin resin or a polycarbonate resin which is an amorphous resin is particularly preferable. Specific examples of the polyester resin, the cycloolefin resin, and the polycarbonate resin are as described above for the transparent resin film, but the moisture content is selected from among them. In this way, since the protective film having a low water content can be used, the water content of the protective film can be further controlled, and the crystallization of the transparent conductive film can be sufficiently performed, so that the resistance value of the transparent conductive film can be more reliably prevented from being abnormal and improved. The adhesion between the transparent conductive film and the substrate prevents the film from peeling off.

The protective film may be the same as the transparent resin film, and the surface may be subjected to an etching treatment such as sputtering, corona discharge, fire blasting, ultraviolet ray irradiation, electron beam irradiation, chemical change, oxidation, or undercoating treatment to adhere to the protective film. The adhesion of the agent layer or the like is improved. Further, before the formation of the adhesive layer, the surface of the protective film may be dedusted and purified by solvent washing or ultrasonic cleaning.

The water content of the protective film is preferably 1.0 × 10 ^-3 g or less per 10 cm × 10 cm, preferably 0.9 × 10 ^-3 g or less per 10 cm × 10 cm, more preferably 0.5 × 10 ^-3 g or less per 10 cm × 10 cm. Further, since the moisture content varies depending on the environment, it is preferable to satisfy the above range when the sputtering film formation or crystallization step is provided. Thereby, the resistance value of the transparent conductive film can be prevented from being abnormal, and the adhesion between the transparent conductive film and the substrate can be improved, and the film can be prevented from peeling off. Further, since the degassing treatment before the film formation by the heating step or the like as the pretreatment is not required as the pretreatment, the production efficiency is improved.

The moisture content (water content) of the protective film is preferably 0.50% by weight or less, preferably 0.40% by weight or less, more preferably 0.30% by weight or less. In this way, since the protective film having a low water content can be used, the water content of the protective film can be further controlled, and the crystallization of the transparent conductive film can be sufficiently performed, so that the resistance value of the transparent conductive film can be more reliably prevented from being abnormal and improved. The adhesion between the transparent conductive film and the substrate prevents the film from peeling off.

The thickness of the protective film is preferably from 1 to 150 μm, preferably from 2 to 120 μm, more preferably from 5 to 100 μm. The thinner the thickness of the protective film, the more the water content of the protective film can be suppressed, and the crystallization of the transparent conductive film can be sufficiently performed. Therefore, the resistance value of the transparent conductive film can be more reliably prevented, and the transparent conductive film can be further improved. The adhesion of the substrate prevents the film from peeling off. By setting it as the said range, the conveyance of the roll-to-roll method can be improved. Moreover, from the viewpoint of preventing cracking of the transparent conductive thin film laminate in the roll-to-roll method, the thickness of the protective film is preferably equal to or greater than the thickness of the transparent resin film.

(Conductive layer) From the viewpoint of antistatic property, it is preferable that the protective film has a conductive layer on the side opposite to the surface on which the above-mentioned adhesive layer is formed. The conductive layer is preferably formed by coating a conductive composition containing a conductive polymer.

Examples of the conductive polymer contained in the conductive composition include a polyacetylene polymer, a polyparaphenylene polymer, a polyaniline polymer, a polythiophene polymer, and a polyparaphenylene. A vinyl polymer, a polypyrrole polymer, a polyphenylene polymer, a polyester polymer modified by an acrylic polymer, or the like. Preferably, the conductive polymer comprises a polymer selected from the group consisting of a polyacetylene polymer, a polyparaphenylene polymer, a polyaniline polymer, a polythiophene polymer, a polyparaphenylene vinyl polymer, and a polypyrrole. One or more polymers of the group consisting of polymers.

More preferably, a polythiophene-based polymer is used as the above-mentioned conductive polymer. When a polythiophene type polymer is used, a conductive layer excellent in transparency and chemical stability can be formed. Specific examples of the polythiophene-based polymer include polythiophene; poly(3-C _1-8 alkyl-thiophene) such as poly(3-hexylthiophene); and poly(3,4-ethylenedioxythiophene). Poly(3,4-(cyclo)alkylene group (PEDOT), poly(3,4-propanedioxythiophene), poly[3,4-(1,2-cyclohexene)dioxythiophene] Dioxythiophene); polythiophene ethylene and the like.

The above conductive layer can be formed by any appropriate method. The conductive composition is, for example, a dispersion containing the conductive polymer and any appropriate solvent (for example, water), and the conductive polymer is dispersed in the solvent. The dispersion concentration of the conductive polymer in the dispersion is preferably from 0.01% by weight to 50% by weight, preferably from 0.01% by weight to 30% by weight.

As a coating method of the above-mentioned conductive composition, any appropriate method can be employed. For example, a bar coating method, a roll coating method, a gravure coating method, a rod coating method, a slit nozzle coating method, a curtain coating method, a jet knife coating method, and a comma coating method can be mentioned. The drying temperature is typically 50 ° C or higher, preferably 90 ° C or higher, and more preferably 110 ° C or higher. The drying temperature is preferably 200 ° C or lower, more preferably 180 ° C or lower. The drying time is preferably from 1 minute to 1 hour, more preferably from 1 minute to 30 minutes, and most preferably from 1 minute to 10 minutes.

The thickness of the conductive layer is preferably from 1 nm to 500 nm, more preferably from 1 nm to 400 nm, most preferably from 1 nm to 300 nm. If it is such a range, the electrically conductive layer which can control an electrical characteristic can be formed favorably.

The above conductive composition may further contain any appropriate additives as needed. Specific examples of the additive include a dispersion stabilizer, a surfactant, and an antifoaming agent. The type and amount of the additive to be used may be appropriately set depending on the purpose.

(Adhesive Layer) The adhesive layer can be used without particular limitation as long as it has transparency. Specifically, for example, an acrylic polymer, a polyoxymethylene polymer, a polyester, a polyurethane, a polyamide, a polyvinyl ether, a vinyl acetate/vinyl chloride copolymer, or the like can be appropriately selected and used. A polymer such as a polyolefin such as a polyolefin, an epoxy, a fluorine, a natural rubber or a synthetic rubber is used as a base polymer. In particular, an acrylic adhesive is preferably used because it is excellent in optical transparency, and exhibits excellent adhesion properties such as wettability, cohesiveness, and adhesion, and excellent weather resistance and heat resistance.

The method for forming the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include a method in which a pressure-sensitive adhesive composition is applied to a release sheet, dried, and then transferred to a base film (transfer method), directly coated on a protective film, and dried. The method of the adhesive composition (direct printing method) or the method by co-extrusion. Further, an adhesive agent, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a decane coupling agent, or the like may be appropriately used in the adhesive as needed.

The thickness of the adhesive layer is preferably from 5 μm to 100 μm, more preferably from 10 μm to 50 μm, most preferably from 15 μm to 35 μm.

<Touch Panel> The transparent conductive film which is a transparent conductive film from which a carrier film is peeled off, or a transparent conductive film which is a protective film, for example, can be suitably used as a transparent electrode of an electronic device such as a touch panel such as a capacitive method or a resistive film method. .

When the touch panel is formed, another substrate such as glass or polymer film may be bonded to one or both main surfaces of the transparent conductive film via a transparent adhesive layer. For example, it is also possible to form a laminate in which a transparent substrate is bonded to a surface of a transparent conductive film on the side where the transparent conductive film is not formed via a transparent adhesive layer. The transparent substrate may be composed of a single base film, or may be a laminate of two or more base films (for example, laminated via a transparent adhesive layer). Further, a hard coat layer may be provided on the outer surface of the transparent substrate to which the transparent conductive film is bonded. As the adhesive layer for bonding the transparent conductive film and the substrate, as long as it has transparency, it can be used without particular limitation.

EXAMPLES Hereinafter, the present invention will be described in detail by way of Examples. However, the present invention is not limited to the following Examples.

<evaluation>

(1) Determination of thickness

The thickness is measured by using a micrometer thickness meter (manufactured by Mitutoyo Co., Ltd.) having a thickness of 1 μm or more. Further, the thickness was less than 1 μm and was measured by an instantaneous multi-photometry system (MCPD2000 manufactured by Otsuka Electronics Co., Ltd.). The thickness of the nano-size of the ITO film was measured by FB-2000A (manufactured by Hitachi High-Technologies Co., Ltd.), and the film thickness was measured by HF-2000 (manufactured by Hitachi High-Technologies Corporation). . The evaluation results are shown in Table 1.

(2) Determination of water content and water content (water content)

The protective film was cut into a sample of 10 cm × 10 cm □, placed in a heating gasification device (Mitsubishi Chemical Analytech, VA-200 type), and the carrier gas heated at 150 ° C was introduced into the titration unit (Mitsubishi Chemical Analytech, CA- Type 200), the amount of water released during heating was measured by the Karl-Fischer method (gasification method), and the water content and the water content were measured. In addition, the water content is a water content per gram, and can be calculated in the same manner as the water content. The water content and the water content were also measured in the same manner as described above for the transparent resin film. The evaluation results are shown in Table 1.

(3) Determination of the resistance value of the arrival

The transparent conductive film with the carrier film was heat-treated at 120 ° C for 20, 30, and 40 minutes in a hot air circulating oven, and the resistance was measured. The surface resistance was measured by a four-terminal method in accordance with JIS K7194. The evaluation results are shown in Table 1.

(4) Standard deviation of surface resistance value The transparent conductive film with a carrier film which was subjected to heat treatment at 120 ° C for 30 minutes in the measurement of the resistance value described above, and the surface resistance value of five places were measured at intervals of 15 cm in the width direction. , to find its standard deviation. The evaluation results are shown in Table 1.

(5) Crystallization rate The crystallization rate of the crystallization of the amorphous transparent conductive film was evaluated by the change in the resistance value. Here, the transparent conductive film (Reference Example 1) having no protective film is referred to as a reference value of the crystallization rate. The evaluation results are shown in Table 1.

○: The crystallization rate is the same as the reference value ×: The crystallization rate is slower than the reference value

(6) Adhesion The measurement was carried out in accordance with JIS K-5600. The transparent conductive film with the carrier film was heat-treated at 130 ° C for 90 minutes in a hot air circulating oven, and then the sample was cut into 5 cm squares, and the transparent conductive film (ITO) surface was drawn by a cutter at intervals of about 1 mm. Each of the 11 scratches in the vertical and horizontal directions was made into 100 grids. Applying a scotch tape (made by Sekisui Co., Ltd., #252), and pressing it back 10 times with a spatula, the tape is quickly peeled off, and the area of 1/4 or more of one square is peeled off. Whether the conductive film is peeled off. Further, the pressurizing and peeling directions of the spatula were changed, and the second step was repeated, and the second pressing was performed by rotating the transparent tape by 90°. The evaluation results are shown in Table 1.

○: no peeling (5/100 or less), good adhesion. ×: peeling (larger than 5/100), poor adhesion

[Example 1] (Formation of a cured resin layer) 100 parts by weight of an ultraviolet curable resin composition (trade name "UNIDIC (registered trademark) RS29-120" manufactured by DIC Corporation, and urethane-based polyfunctional polyacrylic acid) (Ester) and 0.2 parts by weight of a crosslinked acrylic-styrene-based spherical particle (SSX105) manufactured by Sekisui Co., Ltd. having a diameter of 3 μm, and a curable resin composition containing spherical particles is applied to a polycyclic ring having a thickness of 50 μm. One surface of an olefin film (trade name "ZEONOR (registered trademark), in-plane birefringence 0.0001" manufactured by ZEON, Japan) was irradiated with ultraviolet rays from the surface to form a second cured resin layer having a thickness of 1 μm. The first cured resin layer was formed on the other side of the polycycloolefin film so as to have a thickness of 1 μm in the same manner as described above except that the spherical particles were not contained.

(Formation of Optical Adjustment Layer) The ultraviolet curable composition containing zirconium oxide particles having a refractive index of 1.62 as an optical adjustment layer was applied to the first cured resin layer side of the polycycloolefin film having the cured resin layer formed on both sides (JSR Corporation) The product name "OPSTAR-Z7412" is formed to form a coating layer. Then, after drying at 80 ° C for 3 minutes, the coating layer was irradiated with ultraviolet rays in a form of a high-pressure mercury lamp (80 W/cm, 15 cm condensing type: cumulative light amount 300 mj) in the form of ozone from the side on which the coating layer was formed, to have a thickness of 0.1 μm. In this way, an optical adjustment layer is formed.

(Formation of Transparent Conductive Film) A parallel-type coil type magnetron sputtering apparatus is mounted with a sintered body target containing indium oxide and tin oxide in a weight ratio of 90:10, and the substrate is conveyed while being vacuum-discharged. The gas is evacuated by a partial pressure of water of 5 × 10 ^-4 Pa. After that, the amount of introduction of argon gas and oxygen gas was adjusted, and the substrate was conveyed at a conveying speed of 7.7 m/min and a conveying tension of 40 to 120 N, and an optical adjustment layer (first hardened resin layer) was applied by DC sputtering at an output of 12.5 kW. Film formation was performed to form an ITO film having a thickness of 22 nm. The surface resistance of the obtained ITO was measured by a four-terminal method and found to be 300 Ω/□.

(Formation of Carrier Film) An acrylic polymer having a weight average molecular weight of 600,000 was obtained by a typical solution polymerization using butyl acrylate/acrylic acid = 100/6 (weight ratio). To 100 parts by weight of the acrylic polymer, 6 parts by weight of an epoxy-based crosslinking agent (trade name "TETRAD-C (registered trademark)" by Mitsubishi Gas Chemical Co., Ltd.) was added to prepare an acrylic pressure-sensitive adhesive. The acrylic adhesive was applied to one surface of a polycycloolefin film (trade name "ZEONOR (registered trademark)" manufactured by ZEON, Japan) having a thickness of 50 μm as a protective film, and heated at 150 ° C for 90 seconds to form an adhesive having a thickness of 10 μm. Floor. Next, the surface of the pressure-sensitive adhesive layer was bonded to a polyfluorene-treated surface of a PET release sheet (thickness: 25 μm) which was subjected to polyfluorination treatment on one surface, and stored at 50 ° C for two days to prepare a carrier film with a release sheet. Further, the release sheet was removed at the time of use, and a carrier film was used.

(Formation of Transparent Conductive Film with Carrier Film) A protective film with an adhesive layer attached to the carrier film on the surface of the transparent conductive film on which the transparent conductive film is not formed is formed to form a transparent conductive film with a carrier film.

[Examples 2 to 6] A transparent conductive film with a carrier film was produced in the same manner as in Example 1 except that the base material and the thickness of the transparent resin film and the protective film were changed as shown in Table 1 in Example 1. Further, regarding the substrate described in Table 1, a polyethylene terephthalate film (T612E25, manufactured by Mitsubishi Plastics Co., Ltd.) was used for the PET, and a polycarbonate resin (trade name "PANLITE" manufactured by Teijin) was used for the PC.

[Comparative Example 1] A polyethylene terephthalate film (manufactured by Mitsubishi Plastics Co., Ltd., T612E25) was used as a protective film in place of the polycycloolefin film in Example 1, and the same procedure as in Example 1 was carried out. A transparent conductive film with a carrier film.

[Comparative Examples 2 to 3] A transparent conductive film with a carrier film was produced in the same manner as in Example 1 except that the base material and the thickness of the protective film were changed as shown in Table 1 in Example 1. Further, regarding the substrate described in Table 1, a polyethylene terephthalate film (T612E25, manufactured by Mitsubishi Plastics Co., Ltd.) was used for the PET, and a polycarbonate resin (trade name "PUREACE" manufactured by Teijin) was used for the PC.

[Reference Example 1] In Example 1, no carrier film was formed, and only a transparent conductive film was produced.

(Results and Investigation) The transparent conductive film of the carrier film of Examples 1 to 6 was heated at 120 ° C for about 20 minutes to complete the crystallization from amorphous to crystalline, and the change in resistance value (surface resistance value) was obtained. Also small, the resistance value is low. Good results were also obtained with respect to the crystallization rate of the reference (Reference Example 1). Moreover, the adhesion to the transparent conductive film is also high, and film peeling does not occur. On the other hand, the transparent conductive film of the carrier film of Comparative Examples 1 to 3 did not complete the crystallization from amorphous to crystalline even after heating at 120 ° C for about 40 minutes, and reached the resistance value (surface The resistance value) also changes greatly, and the resistance value is high. The crystallization rate with respect to the reference (Reference Example 1) is also slow. Further, the adhesion to the transparent conductive film is also low, and film peeling occurs.

1...protective film 2...adhesive layer 3...transparent resin film 4...transparent conductive film 5...second hardened resin layer 6...first hardened resin layer 7...optical adjustment layer 10...carrier film 20...transparent conductive film

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a transparent conductive film with a carrier film according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view showing a transparent conductive film with a carrier film according to another embodiment of the present invention.

Claims (6)

A transparent conductive film with a carrier film, comprising: a transparent conductive film comprising a transparent resin film and a transparent conductive film; and a carrier film comprising an adhesive layer and a protective film, wherein the adhesive layer is disposed on the transparent conductive material The transparent film is formed on the surface side of the transparent resin film, the transparent conductive film is an indium tin composite oxide, and the protective film is made of a cycloolefin resin, and the water content of the protective film is 1.0 × 10 per 10 cm × 10 cm ^{- 3} g or less. The transparent conductive film of the carrier film according to claim 1, wherein the transparent resin film has a first cured resin layer provided on a surface side of the transparent conductive film, and a second cured resin layer provided on the transparent conductive layer The opposite side of the membrane. The transparent conductive film with a carrier film according to claim 2, further comprising one or more optical adjustment layers between the first cured resin layer and the transparent conductive film. The transparent conductive film of the carrier film according to claim 1 or 2, wherein the protective film has a thickness of from 1 μm to 150 μm. The transparent conductive film with a carrier film according to claim 1 or 2, wherein the protective film has a water content of 0.50% by weight or less. A transparent conductive film with a carrier film according to claim 1 or 2, wherein the protective film is formed with the aforementioned adhesive layer. The opposite side of the surface is further provided with a conductive layer.