TW201641278A - Transparent conductive film - Google Patents

Abstract

The transparent conductive film of the present invention comprises, in the thickness direction, a transparent substrate, a refractive index adjusting layer containing a resin and inorganic particles, an adhesive layer containing an inorganic atom, and a transparent conductive layer, and the adhesion layer is in contact with the refractive index adjusting layer. The ratio of the number of inorganic atoms to the number of carbon atoms in the vicinity of the interface of the side of the refractive index adjusting layer in contact with the adhesion layer is less than 0.05.

Description

Transparent conductive film

The present invention relates to a transparent conductive film, and more particularly to a transparent conductive film used for a film for a touch panel or the like.

A film for a touch panel including a transparent wiring layer containing indium tin composite oxide (ITO) or the like is known as an image display device. The film for a touch panel is usually produced by patterning an ITO layer into a wiring pattern by laminating an ITO layer or the like on a transparent conductive film (see, for example, Patent Document 1).

Patent Document 1 discloses a film for a touch panel in which an ultraviolet curable resin layer, a transparent inorganic oxide layer, and a transparent conductive layer are sequentially laminated on one surface of a transparent substrate, and the ultraviolet curable resin layer is simultaneously The number of inorganic elements B in the inorganic oxide of the layer, which is composed of an organic component and an inorganic oxide, and at least in a region within 10 nm from the surface in contact with the transparent inorganic oxide layer, relative to the organic element in the organic component The ratio of the number A, that is, B/A is 0.05 or more and 0.35 or less in terms of the element ratio.

The touch panel improves the adhesion between the ultraviolet curable resin layer containing an inorganic oxide and the transparent inorganic oxide layer laminated thereon in order to adjust the refractive index.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-211790

In recent years, with the demand for enlargement and thinning of image display devices, demands for enlargement and thinning of transparent conductive films have been increasing. However, when the ITO layer of the transparent conductive film is increased in size or thinned, the resistance of the entire or a part of the ITO layer increases, and as a result, the functions such as the sensitivity of the touch panel are lowered. Therefore, the industry is seeking to reduce the specific resistance of the ITO layer (low resistance).

Further, with the expansion of the use of the image display device, durability in an environment where the ester durability is more stringent than the previous durability standard (for example, a humidified environment of 90% at 60 ° C) is being sought. Among them, the interlayer adhesion of the layers constituting the transparent conductive film directly causes the operation of the image display device to be poor, so that it is required to have high durability (representatively, the adhesion is durable for 150 hours or more in an environment of 85% at 85 ° C; Sex) is especially strong. In general, as for the interlayer adhesion, the contact area of each layer is increased as much as possible. Therefore, the greater the surface roughness of each layer or any layer constituting the transparent conductive film, the more advantageous it is in terms of adhesion. However, such a transparent conductive film has a surface roughness of a transparent conductive layer (for example, an ITO layer), so that it is difficult to perform crystallization conversion, and a transparent conductive film having a low specific resistance cannot be obtained.

Further, in Patent Document 1, there is a case where a large amount of inorganic oxide particles are present in the vicinity of the surface of the ultraviolet curable resin layer, and the surface is roughened, and the surface of the transparent conductive layer (ITO layer or the like) provided thereon is also roughened. As a result, although the adhesion between the ultraviolet curable resin layer and the transparent inorganic oxide layer is improved, the specific resistance value of the transparent conductive layer is increased, and the reduction in resistance cannot be achieved.

An object of the present invention is to provide a transparent conductive film which is excellent in adhesion between a refractive index adjusting layer (particularly, adhesion after exposure to an environment of 85% at 85 ° C) and which is excellent in low electrical resistance of a transparent conductive layer.

The present invention [1] includes a transparent conductive film comprising, in the thickness direction, a transparent substrate, a refractive index adjusting layer containing a resin and inorganic particles, an adhesive layer containing an inorganic atom, and a transparent conductive layer, and the above-mentioned adhesion The layer is in contact with the refractive index adjusting layer, and the folding The ratio of the number of inorganic atoms to the number of carbon atoms in the vicinity of the interface of the side of the radiation rate adjusting layer in contact with the above-mentioned adhesion layer is less than 0.05.

The invention [2] comprising the transparent conductive film according to [1], wherein the adhesion layer contains an inorganic oxide having a non-stoichiometric composition.

The invention [3] contains the transparent conductive film according to [2], wherein the inorganic compound having the non-stoichiometric composition is a non-stoichiometric composition of a ruthenium compound.

The transparent conductive film according to any one of [1] to [3] wherein the adhesion layer contains a ruthenium atom and includes a bond of Si2p orbital determined by X-ray photoelectron spectroscopy. It can be an area of 99.0 eV or more and less than 103.0 eV.

The transparent conductive film according to any one of [1] to [4], further comprising an optical adjustment layer containing an inorganic oxide between the adhesion layer and the transparent conductive layer.

The transparent conductive film according to any one of [1] to [5] wherein the transparent conductive layer has a surface resistance value of less than 200 Ω/□.

The transparent conductive film according to any one of [1] to [6] wherein the transparent conductive layer has a specific resistance value of 3.7 × 10 ^-4 Ω. Below cm.

According to the transparent conductive film of the present invention, the adhesion between the refractive index adjusting layer and the layer provided thereon (especially, the adhesion after exposure to an environment of 85% at 85 ° C) is good. Further, since the specific resistance of the transparent conductive layer is lowered, the conductivity is excellent.

1‧‧‧Transparent conductive film

2‧‧‧Transparent substrate

3‧‧‧Refractive index adjustment layer

4‧‧ ‧ close layer

5‧‧‧Optical adjustment layer

6‧‧‧Transparent conductive layer

Fig. 1 is a side sectional view showing an embodiment of a transparent conductive film of the present invention.

Fig. 2 is a side cross-sectional view showing another embodiment (an embodiment in which the optical adjustment layer is not provided) of the transparent conductive film of the present invention.

In Fig. 1, the upper and lower sides of the paper are in the up and down direction (thickness direction, first direction), and the paper surface The upper side is the upper side (the thickness direction side, the first direction side), and the lower side of the paper surface is the lower side (the other side in the thickness direction and the other side in the first direction).

Transparent conductive film

The transparent conductive film 1 has a film shape (including a sheet shape) having a specific thickness, and extends in a specific direction (plane direction) orthogonal to the thickness direction, and has a flat upper surface and a flat lower surface. The transparent conductive film 1 is, for example, a component such as a base material for a touch panel provided in an image display device, that is, an image display device. In other words, the transparent conductive film 1 is used for producing an image display device or the like, and does not include an image display element such as an LCD (liquid crystal display) module, and is separately circulated and available in the form of a component. The industry's components.

Specifically, as shown in FIG. 1 , the transparent conductive film 1 includes, for example, a transparent substrate 2 , a refractive index adjusting layer 3 , an adhesion layer 4 , an optical adjustment layer 5 , and a transparent conductive layer 6 in the thickness direction. In other words, the transparent conductive film 1 includes the transparent substrate 2, the refractive index adjusting layer 3 disposed on the transparent substrate 2, the adhesion layer 4 disposed on the refractive index adjusting layer 3, and optical adjustment disposed on the adhesion layer 4. The layer 5 and the transparent conductive layer 6 disposed on the optical adjustment layer 5 are provided.

The transparent conductive film 1 preferably includes a transparent substrate 2, a refractive index adjusting layer 3, an adhesion layer 4, an optical adjustment layer 5, and a transparent conductive layer 6. Hereinafter, each layer will be described in detail.

2. Transparent substrate

The transparent substrate 2 is the lowermost layer of the transparent conductive film 1 and is a substrate that ensures the mechanical strength of the transparent conductive film 1. The transparent substrate 2 collectively supports the transparent conductive layer 6 and the refractive index adjusting layer 3, the adhesion layer 4, and the optical adjustment layer 5.

The transparent substrate 2 is, for example, a polymer film having transparency. Examples of the material of the polymer film include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate; for example, polymethacrylate (meth)acrylic resin (acrylic resin and/or methacrylic resin); olefin resin such as polyethylene, polypropylene, cycloolefin polymer; for example, polycarbonate resin, polyether oxime resin, polyarylate Resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, polystyrene resin, drop Alkene resin, etc. These polymer films may be used alone or in combination of two or more. From the viewpoints of transparency, heat resistance, mechanical strength, and the like, a polyester resin is preferable, and PET is more preferable.

The thickness of the transparent substrate 2 is, for example, 2 μm or more, preferably 20 μm or more, from the viewpoints of mechanical strength, scratch resistance, and dot characteristics when the transparent conductive film 1 is used as a film for a touch panel. For example, it is 300 μm or less, preferably 200 μm or less, and more preferably 150 μm or less.

Further, a hard coat layer, an anti-adhesion layer, an easy-adhesion layer, an adhesive layer, a separator, or the like may be provided on the upper surface and/or the lower surface of the transparent substrate 2 as needed.

3. Refractive index adjustment layer

The refractive index adjusting layer 3 and the optical adjustment layer 5 described later are both adjusted in refractive index of the transparent conductive film 1 after the transparent conductive layer 6 is formed into a wiring pattern in a subsequent step to make the pattern portion and the non-pattern portion. The difference is not recognized (ie, to suppress viewing of the wiring pattern). Further, the refractive index adjusting layer 3 is also a scratch protective layer for making the upper surface of the transparent conductive layer 6 (that is, the surface of the transparent conductive film 1) less likely to cause scratches (to obtain excellent scratch resistance).

The refractive index adjusting layer 3 has a film shape (including a sheet shape), and is disposed on the entire upper surface of the transparent substrate 2, for example, in contact with the upper surface of the transparent substrate 2.

The refractive index adjusting layer 3 is a resin layer formed of a resin composition.

The resin composition contains a resin and an inorganic atom. By including an inorganic atom, the refractive index of the refractive index adjusting layer 3 can be adjusted to an appropriate value, whereby the visibility of the wiring pattern can be suppressed or the light transmittance can be improved. The inorganic atom preferably constitutes an inorganic particle. That is, the resin composition preferably contains a resin and inorganic particles, and more preferably consists of a resin and inorganic particles.

Examples of the resin include a curable resin and a thermoplastic resin (for example, a polyolefin tree). The grease or the like is preferably a curable resin.

Examples of the curable resin include an active energy ray-curable resin which is cured by irradiation with an active energy ray (specifically, ultraviolet rays, an electron beam, or the like); for example, a thermosetting resin which is cured by heating, and the like. Preferably, an active energy ray-curable resin is mentioned.

The active energy ray-curable resin may, for example, be a polymer having a functional group containing a polymerizable carbon-carbon double bond in the molecule. Examples of such a functional group include a vinyl group, a (meth) acrylonitrile group (methacryl fluorenyl group and/or an acryl fluorenyl group).

Examples of the active energy ray-curable resin include a (meth)acrylic resin (acrylic resin and/or methacrylic resin) containing a functional group.

In addition, examples of the resin other than the active energy ray-curable resin include a urethane resin, a melamine resin, an alkyd resin, a decyl siloxane polymer, and an organic decane condensate.

The resin may be used singly or in combination of two or more.

The content ratio of the resin to the total amount of the resin and the inorganic atom is, for example, 20% by mass or more, preferably 22% by mass or more, more preferably 25% by mass or more, and further preferably 90% by mass or less. It is 80% by mass or less, more preferably 70% by mass or less, and still more preferably 50% by mass or less.

As the inorganic particles, an appropriate material can be selected according to the refractive index obtained by the refractive index adjusting layer 3, and examples thereof include cerium oxide particles (including hollow nano cerium oxide particles); for example, zirconia, titanium oxide, and the like. A metal oxide particle such as aluminum oxide, zinc oxide or tin oxide; for example, a carbonate particle containing calcium carbonate or the like. These inorganic particles may be used alone or in combination of two or more. The metal oxide particles are preferred, and from the viewpoint of high refractive index, high refractive index particles such as titanium oxide particles and zirconium oxide particles are more preferable, and zirconia particles (ZrO ₂ ) are more preferable. .

Further, in order to ensure the dispersibility of the refractive index adjusting layer 3, the inorganic particles may be chemicalized. Learn to modify.

The average particle diameter of the inorganic particles is, for example, 10 nm or more, preferably 15 nm or more, more preferably 20 nm or more, and further preferably 100 nm or less, preferably 60 nm or less, and more preferably 40 nm or less. By setting the average particle diameter of the inorganic particles within the above range, the precipitation of the inorganic particles can be adjusted, and the number of particles in the vicinity of the upper surface of the refractive index adjusting layer 3 can be adjusted.

In the present invention, the average particle diameter of the particles can be measured by Coulter counters using a Coulter Multisizer manufactured by Beckman Coulter.

The content ratio of the inorganic atom (especially the inorganic particles) is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, and further preferably 30 parts by mass or more. 50% by mass or more, for example, it is 80% by mass or less, preferably 78% by mass or less, and more preferably 75% by mass or less.

By setting the content ratio of the inorganic atoms to the above lower limit or more, the refractive index can be adjusted to an appropriate range. In addition, by setting the content ratio of the inorganic atoms to the upper limit or less, the number of particles in the vicinity of the upper surface of the refractive index adjusting layer 3 can be made less than or equal to the required amount, and the specific resistance value of the transparent conductive layer 6 can be lowered.

The refractive index of the refractive index adjusting layer 3 can be appropriately adjusted by an inorganic atom (preferably inorganic particles), and is, for example, 1.50 or more and 1.80 or less.

The refractive index adjusting layer 3 preferably contains high refractive index particles from the viewpoint of improving the light transmittance of the transparent conductive film 1. When the high refractive index particles (preferably zirconia particles) are contained as the inorganic particles, the refractive index adjusting layer 3 has a refractive index of 1.55 or more, preferably 1.60 or more, more preferably 1.62 or more, and further, for example, 1.74. Hereinafter, it is preferably 1.73 or less, more preferably 1.70 or less. When it is in the above range, the number of inorganic particles existing in the vicinity of the upper surface of the refractive index adjusting layer 3 can be adjusted to a small amount, and the ratio of the number of inorganic atoms to the number of carbon atoms can be easily made to be less than 0.05.

In the present invention, the refractive index can be measured by a spectroscopic ellipsometer.

The thickness of the refractive index adjusting layer 3 is, for example, 30 nm or more, preferably 50 nm or more, more preferably 100 nm or more, and further, for example, 1000 nm or less, from the viewpoint of suppressing the visibility of the wiring pattern and achieving low resistance. Good is below 500nm.

The thickness of the refractive index adjusting layer 3 was measured by cross-sectional observation using a transmission electron microscope (TEM).

In the vicinity of the interface on the upper side of the refractive index adjusting layer 3 (the side in contact with the adhesion layer 4), that is, in the vicinity of the upper surface of the refractive index adjusting layer 3, the ratio of the number of inorganic atoms I to the number of carbon atoms C (I /C) is less than 0.05, preferably less than 0.04. Further, for example, it is 0.00 or more. By setting the I/C ratio in the vicinity of the upper surface to be within the above range, the number of inorganic atoms (especially inorganic particles) in the vicinity of the upper surface can be reduced, so that the upper surface of the refractive index adjusting layer 3 and The surface of the transparent conductive layer 6 disposed thereon is smooth. Therefore, the specific resistance value of the transparent conductive layer 6 can be lowered.

The region in the vicinity of the upper surface is a region in the thickness direction from the upper surface (the surface on the upper side), specifically, a region from the upper surface (0 nm) of the refractive index adjusting layer 3 to within 10 nm of the lower side. The I/C ratio of the region in the vicinity of the upper surface of the refractive index adjusting layer 3 can be determined by measuring the upper surface of the refractive index adjusting layer 3 by X-ray photoelectron spectroscopy.

Furthermore, when the I/C ratio is calculated in the vicinity of the upper surface, non-metal atoms such as oxygen atoms are not included in the calculation. For example, when the refractive index adjusting layer 3 contains zirconia particles as inorganic particles, the ratio is the ratio of zr atom number Zr to the number of carbon atoms C (Zr/C), and contains cerium oxide particles (SiO ₂ ). In the case of inorganic particles, the ratio is the ratio of the number of germanium atoms Si to the number of carbon atoms C (Si/C). When titanium oxide particles are contained as inorganic particles, the ratio is the number of titanium atoms Ti relative to carbon. The ratio of the number of atoms C (Ti/C) and the like. Further, when the refractive index adjusting layer 3 contains a plurality of inorganic particles, the ratio is calculated as a total of the ratios of the respective atoms.

Further, at the time of measurement, the upper surface of the refractive index adjusting layer 3 was etched in the thickness direction by about 1 to 2 nm from the viewpoint of eliminating the influence of the upper surface contamination. In the case where a layer such as the adhesion layer 4 is laminated on the refractive index adjustment layer 3, the depth distribution (the measurement pitch is 1 nm per SiO ₂ ) is measured by X-ray photoelectron spectroscopy, and the adhesion layer is measured. The terminal portion of 4 is defined as the upper surface (0 nm) of the refractive index adjusting layer 3. The end portion of the adhesion layer 4 is a depth position at which the element ratio of the inorganic atoms constituting the adhesion layer 4 becomes a half value with respect to the peak value in the depth distribution. When the inorganic layer constituting the adhesion layer 4 and the optical adjustment layer 5 is the same, the elemental ratio of the inorganic atom including the optical adjustment layer 5 to the depth at which the peak value becomes a half value is determined as the upper surface (0 nm).

4. Adhesive layer

The adhesion layer 4 is a layer in which the refractive index adjustment layer 3 and the optical adjustment layer 5 described later are in close contact with each other, and the refractive index adjustment layer 3 and the optical adjustment layer 5 are firmly bonded. By the presence of the adhesion layer 4, even when the refractive index adjustment layer 3 having a smooth upper surface is provided, the transparent conductive film 1 capable of suppressing peeling after being exposed to an environment of 85% at 85 ° C can be obtained.

The adhesion layer 4 has a film shape (including a sheet shape) and is disposed on the entire upper surface of the refractive index adjustment layer 3 so as to be in contact with the upper surface of the refractive index adjustment layer 3.

The adhesion layer 4 contains an inorganic atom, and is preferably formed of an inorganic substance such as a single component or an inorganic compound, and is preferably formed of an inorganic compound.

The inorganic atom contained in the adhesion layer 4 is preferably a germanium atom (Si) or the like. Specifically, the adhesion layer 4 is formed of a ruthenium element or a ruthenium compound, and is preferably formed of a ruthenium compound from the viewpoint of transparency.

Further, examples of the inorganic compound include inorganic compounds having a stoichiometric composition and inorganic compounds having a non-stoichiometric composition.

Examples of the inorganic compound having a stoichiometric composition include cerium oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), cerium oxide (Nb ₂ O ₅ ), and titanium oxide (TiO ₂ ).

Examples of the inorganic compound having a non-stoichiometric composition include, for example, niobium nitride (example) Inorganic nitrides such as SiCx, 0.1≦x<1.0); inorganic carbides such as ruthenium carbide (for example, SiNx, 0.1≦x<1.3); inorganic oxidation such as ruthenium oxide (for example, SiOx, 0.1≦x<2.0) Things and so on.

The inorganic compounds may be in a single composition or a mixture of a plurality of components.

The adhesion layer 4 is preferably an inorganic compound containing a non-stoichiometric composition, more preferably an inorganic oxide containing a non-stoichiometric composition. Thereby, the adhesion of the adhesion layer 4 can be made better.

Further, in the case where the adhesion layer 4 contains a ruthenium atom (particularly a ruthenium compound), the adhesion layer 4 is preferably a ruthenium compound containing a non-stoichiometric composition (for example, the above-described non-stoichiometric composition of ruthenium carbide, ruthenium) Carbide, niobium oxide, etc.). More preferably, it is a cerium oxide containing a non-stoichiometric composition.

When the adhesion layer 4 contains a ruthenium atom, the bonding energy of the Si 2p orbital obtained by X-ray photoelectron spectroscopy of the adhesion layer 4 is, for example, 98.0 eV or more, preferably 99.0 eV or more, and more preferably 100.0 eV or more. Further, it is preferably 102.0 eV or more, and further, for example, less than 104.0 eV, preferably less than 103.0 eV, more preferably 102.8 eV or less. By selecting the bonding layer 4 in which the bonding energy of the Si2p track is in the above range, the adhesion of the adhesion layer 4 can be made better. In particular, if the bonding energy of the adhesion layer 4 is set to 99.0 eV or more and less than 103.0 eV, the adhesion layer 4 may contain an inorganic compound (especially a ruthenium compound) having a non-stoichiometric composition, so that a good light transmittance can be maintained. And more surely improve the adhesion.

The above bonding energy of the adhesion layer 4 can be obtained by measuring the surface of the adhesion layer 4 by X-ray photoelectron spectroscopy.

At the time of measurement, the upper surface of the adhesion layer 4 was etched in the thickness direction by about 1 to 2 nm from the viewpoint of eliminating the influence of the upper surface contamination. In the case where a layer such as the optical adjustment layer 5 is laminated on the adhesion layer 4, the depth distribution (the measurement pitch is 1 nm per SiO ₂ ) is measured by X-ray photoelectron spectroscopy, and the adhesion layer 4 is used. The bonding energy value at the upper end position of the terminal portion of 1 nm or more (preferably, the position on the upper side of 1 nm). In the case where the inorganic atoms constituting the adhesion layer 4 and the optical adjustment layer 5 are the same, the depth ratio of the element ratio of the inorganic atoms including the optical adjustment layer 5 to the peak value is set to the adhesion layer 4 Terminal department. In the case where the thickness of the adhesion layer 4 is 8 nm or less, it is preferable to laminate the optical adjustment layer 5 on the adhesion layer 4 from the viewpoint of ensuring sufficient thickness for measurement, and to measure by the depth distribution. .

The refractive index of the adhesion layer 4 is, for example, less than 2.00, preferably 1.90 or less, more preferably 1.85 or less, and further preferably 1.50 or more, preferably 1.55 or more, and more preferably 1.60 or more. The adhesion layer 4 is preferably higher than the refractive index of the optical adjustment layer 5 described later, and the difference between the refractive index of the adhesion layer 4 and the refractive index of the optical adjustment layer 5 is, for example, 0.01 or more, preferably 0.03 or more. For example, it is 0.50 or less, preferably 0.40 or less. By setting the refractive index of the adhesion layer 4 within the above range, the optical characteristics such as the light transmittance of the transparent conductive film 1 can be improved.

The thickness of the adhesion layer 4 is, for example, 1 nm or more, preferably 2 nm or more, and is, for example, 10 nm or less, preferably 8 nm or less, more preferably 5 nm or less. By setting the thickness of the adhesion layer 4 to the above lower limit or more, the adhesion of the adhesion layer 4 is improved. On the other hand, by setting the thickness of the adhesion layer 4 to be equal to or less than the above upper limit, light absorption of the adhesion layer 4 can be suppressed, and a decrease in light transmittance can be suppressed.

The thickness of the adhesion layer 4 was measured by cross-sectional observation using a transmission electron microscope (TEM).

5. Optical adjustment layer

Both the optical adjustment layer 5 and the refractive index adjustment layer 3 are for optical properties (for example, refractive index) of the transparent conductive film 1 in order to suppress the visibility of the wiring pattern of the transparent conductive layer 6 and to ensure excellent transparency of the transparent conductive film 1. Adjust the layer.

The optical adjustment layer 5 has a film shape (including a sheet shape) and is disposed on the entire upper surface of the adhesion layer 4 so as to be in contact with the upper surface of the adhesion layer 4.

The optical adjustment layer 5 is preferably formed of an inorganic substance.

Examples of the composition of the inorganic material include an oxide, a fluoride, and the like.

Examples of the oxide (inorganic oxide) include cerium oxide (specifically, cerium oxide (SiO ₂ ), cerium oxide (SiO), etc.), aluminum oxide (Al ₂ O ₃ ), and cerium oxide (Nb). ₂ O ₅ ), titanium oxide (TiO ₂ ), and the like.

Examples of the fluoride include a fluoride alkali metal such as sodium fluoride (NaF), trisodium hexafluoroaluminate (Na ₃ AlF ₆ ), lithium fluoride (LiF), or magnesium fluoride (MgF ₂ ); for example, fluorine A fluorided alkaline earth metal such as calcium (CaF ₂ ) or barium fluoride (BaF ₂ ); and a rare earth fluoride such as lanthanum fluoride (LaF ₃ ) or cesium fluoride (CeF).

The inorganic substances may be used singly or in combination of two or more.

The inorganic material is preferably an inorganic oxide from the viewpoint of adhesion to the adhesion layer 4, low resistance, and suppression of the wiring pattern. More preferably, it is cerium oxide (SiO ₂ , refractive index 1.47). ). In particular, the optical adjustment layer 5 preferably contains an inorganic oxide as an inorganic substance, and more preferably contains cerium oxide as an inorganic substance.

The refractive index of the optical adjustment layer 5 is preferably different from the refractive index of the refractive index adjustment layer 3, and the difference between the refractive index of the optical adjustment layer 5 and the refractive index of the refractive index adjustment layer 3 is, for example, 0.10 or more, preferably 0.11 or more. Further, for example, it is 0.95 or less, preferably 0.60 or less.

More preferably, the refractive index of the optical adjustment layer 5 is lower than the refractive index of the refractive index adjustment layer 3. That is, it is preferable that the refractive index adjusting layer 3 is a high refractive index layer, and the optical adjustment layer 5 is a low refractive index layer having a refractive index of a higher refractive index layer having a lower refractive index. When the wiring pattern is formed by patterning the transparent conductive layer 6 of the transparent conductive film 1, the difference in reflectance or the color difference caused by the pattern portion and the non-pattern portion can be reduced, and the wiring pattern can be more reliably suppressed. Recognized.

The refractive index of the optical adjustment layer 5 is, for example, less than 1.60, preferably 1.55 or less, more preferably 1.50 or less, and further preferably 1.20 or more, preferably 1.30 or more, and more preferably 1.40 or more.

The thickness of the optical adjustment layer 5 is, for example, 1 nm or more, preferably 3 nm or more, and is, for example, 50 nm or less, preferably 20 nm or less.

The thickness of the optical adjustment layer 5 was measured by cross-sectional observation using a transmission electron microscope (TEM).

The ratio of the thickness of the optical adjustment layer 5 to the thickness of the adhesion layer 4 (the optical adjustment layer 5 / the adhesion layer 4) is, for example, 0.5 or more, preferably 1.0 or more, more preferably from the viewpoint of reducing the resistance. Further, 2.0 or more is, for example, 100 or less, preferably 50 or less, more preferably 30 or less, still more preferably 15 or less.

The ratio of the thickness of the optical adjustment layer 5 to the thickness of the refractive index adjustment layer 3 (the optical adjustment layer 5 / the refractive index adjustment layer 3) is preferably 0.01 or more from the viewpoint of suppressing the visibility of the wiring pattern. Further, it is 0.02 or more, and is, for example, 3.00 or less, preferably 1.00 or less, more preferably 0.50 or less, further preferably 0.30 or less, and particularly preferably 0.20 or less.

6. Transparent conductive layer

The transparent conductive layer 6 is used to form a wiring pattern in a subsequent step to form a conductive layer of the pattern portion.

As shown in FIG. 1, the transparent conductive layer 6 is the uppermost layer of the transparent conductive film 1, and has a film shape (including a sheet shape), and is disposed on the entire surface of the optical adjustment layer 5 so as to be in contact with the upper surface of the optical adjustment layer 5. Upper surface.

The material of the transparent conductive layer 6 is, for example, at least one selected from the group consisting of In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, and W. A metal oxide of a metal. For the metal oxide, the metal atoms shown in the above group may be doped as needed.

Examples of the material of the transparent conductive layer 6 include an indium-containing oxide such as indium tin composite oxide (ITO); for example, a cerium-containing oxide such as lanthanum-tin composite oxide (ATO), and the like, and preferably contains indium oxide. More preferably, ITO is listed.

In the case where ITO is used as the material of the transparent conductive layer 6, the content of the tin oxide (SnO ₂ ) is, for example, 0.5% by mass or more, preferably 3 mass, based on the total amount of the tin oxide and the indium oxide (In ₂ O ₃ ). % or more is, for example, 15% by mass or less, preferably 13% by mass or less. By setting the content of the tin oxide to the above lower limit or more, the durability of the ITO layer can be further improved. By setting the content of the tin oxide to be not more than the above upper limit, the crystallization of the ITO layer can be easily performed, thereby improving the transparency or the stability of the specific resistance.

The "ITO" in the present specification may be a composite oxide containing at least indium (In) and tin (Sn), and may contain additional components other than these. Examples of the additional component include metal elements other than In and Sn, and specific examples thereof include Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, W, and Fe. Pb, Ni, Nb, Cr, Ga, and the like.

The thickness of the transparent conductive layer 6 is, for example, 10 nm or more, preferably 15 nm or more, and is, for example, 45 nm or less, preferably 40 nm or less, more preferably 35 nm or less, still more preferably 30 nm or less, and still more preferably 28 nm or less. By setting the thickness of the transparent conductive layer 6 to the above lower limit or more, the transparent conductive layer 6 such as an ITO layer can be more uniformly crystallized and transformed during the heat treatment. On the other hand, the thickness of the transparent conductive layer 6 is not more than the above upper limit, and there is no fear that the light transmittance of the transparent conductive film 1 is greatly lowered.

The thickness of the transparent conductive layer 6 was measured by cross-sectional observation using a transmission electron microscope (TEM).

The transparent conductive layer 6 may be either crystalline or amorphous, or may be a mixture of crystalline and amorphous. The transparent conductive layer 6 is preferably composed of a crystalline substance, and more specifically, a crystalline ITO layer. Thereby, the transparency of the transparent conductive layer 6 is improved, and the specific resistance value of the transparent conductive layer 6 can be further reduced.

The transparent conductive layer 6 is, for example, a crystalline film. When the transparent conductive layer 6 is an ITO layer, it is immersed in hydrochloric acid (concentration: 5 mass%) at 20 ° C for 15 minutes, and then washed with water and dried. The resistance between the terminals at intervals of about 15 mm was measured. In the present specification, when immersed in water (20° C.; concentration: 5% by mass), washed with water, and dried, when the inter-terminal resistance at intervals of 15 mm is 10 kΩ or less, the ITO layer is regarded as crystalline.

7. Method for producing transparent conductive film

Next, a method of manufacturing the transparent conductive film 1 will be described.

In order to manufacture the transparent conductive film 1, for example, the refractive index adjusting layer 3, the adhesion layer 4, the optical adjustment layer 5, and the transparent conductive layer 6 are sequentially provided on the transparent substrate 2. The details will be described below.

First, a known or commercially available transparent substrate 2 is prepared.

Thereafter, from the viewpoint of the adhesion between the transparent substrate 2 and the refractive index adjusting layer 3, the surface of the transparent substrate 2 may be subjected to sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, or chemical, as needed. Etching or undercoating treatment such as treatment, oxidation, or the like. Further, the transparent substrate 2 can be dusted and cleaned by solvent washing or ultrasonic cleaning.

Then, the refractive index adjusting layer 3 is provided on the transparent substrate 2. For example, the refractive index adjusting layer 3 is formed on the upper surface of the transparent substrate 2 by wet coating the resin composition on the transparent substrate 2.

Specifically, a diluent obtained by diluting a resin composition with a solvent is prepared, and then the diluted solution is applied onto the upper surface of the transparent substrate 2, and the diluted solution is dried.

The solvent is, for example, an organic solvent, an aqueous solvent (specifically, water), and the like, and an organic solvent is preferred. The organic solvent may, for example, be an alcohol compound such as methanol, ethanol or isopropanol; for example, a ketone compound such as acetone, methyl ethyl ketone or methyl isobutyl ketone (MIBK); for example, ethyl acetate or butyl acetate; An ester compound; for example, an aromatic compound such as toluene or xylene. These solvents may be used alone or in combination of two or more. A ketone compound is preferred.

The solid content concentration of the diluent is, for example, 1% by mass or more and 30% by mass or less.

The coating method can be appropriately selected depending on the diluent and the transparent substrate. For example, a dip coating method, an air knife coating method, a curtain coating method, a roll coating method, a bar coating method, a gravure coating method, an extrusion coating method, etc. are mentioned.

The drying temperature is, for example, 60 ° C or higher, preferably 70 ° C or higher, more preferably 80 ° C. The upper portion is, for example, 200 ° C or lower, preferably 150 ° C or lower.

The drying time is, for example, 0.5 minutes or longer, preferably 1 minute or longer, more preferably 2 minutes or longer, and for example, 60 minutes or shorter, preferably 20 minutes or shorter. By setting the drying time to the above range, the inorganic particles dispersed in the resin can be precipitated by appropriately adjusting the particle diameter or material of the inorganic particles, and can be lowered on the obtained refractive index adjusting layer 3. The amount of inorganic particles present near the surface.

The resin composition was formed into a film shape on the upper surface of the transparent substrate 2 by the above coating and drying.

Thereafter, when the resin of the resin composition contains the active energy ray-curable resin, the active energy ray-curable resin is cured by irradiating the active energy ray after drying the diluted solution.

Further, in the case where the thermosetting resin is used as the resin of the resin composition, the drying step allows the thermosetting resin to be thermally cured while the solvent is dried.

Then, an adhesion layer 4 is provided on the refractive index adjustment layer 3. The adhesion layer 4 is formed on the upper surface of the refractive index adjustment layer 3 by, for example, a dry method.

Examples of the dry method include a vacuum deposition method, a sputtering method, and an ion plating method. Preferably, a sputtering method is mentioned. By forming the adhesion layer 4 by this method, the high-density adhesion layer 4 can be formed, so that the adhesion between the refractive index adjustment layer 3 and the adhesion layer 4 can be improved.

In the case of using a sputtering method, the inorganic material constituting the adhesion layer 4 may be mentioned as a target. For example, in the case where a layer containing a ruthenium compound such as ruthenium oxide (SiOx) is formed as the adhesion layer 4, Si can be used.

Examples of the sputtering gas include an inert gas such as Ar.

Further, when the adhesion layer 4 contains an inorganic oxide (for example, cerium oxide), a reactive gas such as oxygen may be used in combination. Reactive gas in the case of using a reactive gas in combination The flow ratio is not particularly limited, and the flow ratio of the inert gas to the reactive gas is, for example, 100:0 to 100:3, preferably 100:0.01 to 100:3, more preferably 100:0.01 to 100:1, and further It is preferably 100: 0.01 to 100: 0.5. By setting the flow rate ratio within the above range, it is possible to suppress excessive oxidation of the adhesive layer 4 by the reactive gas supplied from the transparent substrate 2, thereby suppressing a decrease in adhesion.

The discharge gas pressure at the time of sputtering is, for example, 1 Pa or less, preferably 0.1 Pa or more and 0.7 Pa or less from the viewpoint of suppressing a decrease in the sputtering frequency and achieving discharge stability.

Further, the dry method in the formation of the adhesion layer 4 is preferably carried out under cooling. For example, sputtering is performed while cooling the refractive index adjusting layer 3. Specifically, the lower surface of the transparent substrate 2 on which the refractive index adjusting layer 3 is laminated (the surface opposite to the side on which the refractive index adjusting layer 3 is laminated) is brought into contact with a cooling device such as a cooling roll, and sputtering is performed. .

The cooling temperature is, for example, 20 ° C or lower, preferably 10 ° C or lower, more preferably less than 0 ° C, and further, for example, -30 ° C or higher.

The adhesion layer 4 containing an inorganic compound having a non-stoichiometric composition can be formed by cooling. In particular, by forming Si as a target and performing sputtering at a low temperature, it is possible to form a layer containing a non-stoichiometric composition of a ruthenium compound, that is, a ruthenium compound having a bonding energy of Si2p orbital of 99.0 eV or more and less than 103.0 eV. Floor. Therefore, the adhesion layer 4 which can be firmly adhered to the refractive index adjustment layer 3 can be formed reliably.

The power source used for the sputtering method may be, for example, a DC (Direct Current) power supply, an AC (Alternating Current) power supply, an MF (Multiple Frequency) power supply, and an RF (Radio Frequency) power supply. And, also, a combination of these.

Then, the optical adjustment layer 5 is provided on the adhesion layer 4. For example, the optical adjustment layer 5 is formed on the upper surface of the adhesion layer 4 by a dry method.

As a dry method for forming the optical adjustment layer 5, it can be exemplified in the adhesion layer 4 The dry method is preferably a sputtering method.

In the case of the sputtering method, the inorganic material constituting the optical adjustment layer 5 is exemplified as the target. For example, when the optical adjustment layer 5 is formed of a layer containing cerium oxide (SiO ₂ ), Si is exemplified.

Examples of the sputtering gas include an inert gas such as Ar.

Further, when the optical adjustment layer 5 contains an oxide (preferably cerium oxide (SiO ₂ )), it is preferred to use a reactive gas such as oxygen in combination. When the reactive gas is used in combination, the flow ratio of the reactive gas is not particularly limited, and the flow ratio of the inert gas to the reactive gas is, for example, 100:35 to 100:100, preferably 100:40 to 100:60. When the flow ratio is within the above range, the gas barrier layer 4 is provided, and even in an environment in which the reactive gas supplied from the transparent substrate 2 is small, an oxide can be preferably obtained.

The discharge gas pressure at the time of sputtering is, for example, 1 Pa or less, preferably 0.1 Pa or more and 0.7 Pa or less from the viewpoint of suppressing a decrease in the sputtering frequency and achieving discharge stability.

Further, the dry method in forming the optical adjustment layer 5 can be carried out under either cooling or non-cooling.

The power source used in the sputtering method may be, for example, any of a DC power source, an AC power source, an MF power source, and an RF power source, or a combination thereof.

Then, a transparent conductive layer 6 is formed on the upper surface of the optical adjustment layer 5.

The formation of the transparent conductive layer 6 is exemplified by the above dry method, and a sputtering method is preferred.

In the case of the sputtering method, the metal oxide constituting the transparent conductive layer 6 is exemplified as the target, and ITO is preferable. The tin oxide concentration of ITO is, for example, 0.5% by mass or more, preferably 3% by mass or more, and is, for example, 15% by mass or less, preferably 13%, from the viewpoints of durability and crystallization of the ITO layer. %the following.

Examples of the sputtering gas include an inert gas such as Ar. Further, a reactive gas such as oxygen may be used in combination as needed. Flow rate of reactive gas in the case of using a reactive gas in combination The ratio is not particularly limited, and is, for example, 0.1% by flow or more and 5% by flow or less based on the total flow rate ratio of the sputtering gas and the reactive gas.

The discharge gas pressure at the time of sputtering is, for example, 1 Pa or less, preferably 0.1 Pa or more and 0.7 Pa or less from the viewpoint of suppressing a decrease in the sputtering frequency and achieving discharge stability.

The power source used in the sputtering method may be, for example, any of a DC power source, an AC power source, an MF power source, and an RF power source, or a combination thereof.

Further, in order to form the transparent conductive layer 6 having a desired thickness, the target or the sputtering conditions and the like may be appropriately set and a plurality of sputterings may be performed.

Thereby, the transparent conductive film 1 can be obtained.

Then, the transparent conductive layer 6 of the transparent conductive film 1 is subjected to a crystallization conversion treatment as needed.

Specifically, the transparent conductive film 1 is subjected to heat treatment in the air.

The heat treatment can be carried out, for example, using an infrared heater, an oven, or the like.

The heating temperature is, for example, 100 ° C or higher, preferably 120 ° C or higher, and further, for example, 200 ° C or lower, preferably 160 ° C or lower. By setting the heating temperature within the above range, thermal damage of the transparent substrate 2 and impurities generated from the transparent substrate 2 can be suppressed, and crystallization conversion can be surely performed.

The heating time can be appropriately determined depending on the heating temperature, and is, for example, 10 minutes or longer, preferably 30 minutes or longer, and further, for example, 5 hours or shorter, preferably 3 hours or shorter.

Thereby, the transparent conductive film 1 having the crystallized transparent conductive layer 6 can be obtained.

The surface resistivity of the transparent conductive layer 6 of the transparent conductive film 1 obtained in this manner is, for example, less than 200 Ω/□, preferably less than 170 Ω/□, more preferably less than 150 Ω/□, and still more preferably 145 Ω/ □ The following, for example, is 50 Ω/□ or more.

The specific resistance of the transparent conductive layer 6 of the transparent conductive film 1 is, for example, 3.7 × 10 ^-4 Ω. Below cm, preferably 3.5 × 10 ^-4 Ω. Below cm, more preferably 3.3 × 10 ^-4 Ω. Below cm, further preferably 3.1 × 10 ^-4 Ω. Below cm, again, for example, 1.1 × 10 ^-4 Ω. Above cm, preferably 1.4 × 10 ^-4 Ω. More than cm.

The surface resistance value can be obtained by measuring the surface of the transparent conductive layer 6 by a four-terminal method, and the specific resistance value can be calculated from the measured surface resistance value and the thickness of the transparent conductive layer 6.

The total thickness of the transparent conductive film 1 is, for example, 2 μm or more, preferably 20 μm or more, and is, for example, 300 μm or less, preferably 150 μm or less.

Further, it is also possible to form the transparent conductive layer 6 into a wiring pattern such as a stripe shape by a known etching method before or after the crystallization conversion treatment.

Further, in the above-described manufacturing method, the refractive index adjusting layer 3, the adhesion layer 4, the optical adjustment layer 5, and the transparent conductive layer can be sequentially formed on the upper surface of the transparent substrate 2 while the transparent substrate 2 is conveyed by the roll-to-roll method. 6. Alternatively, part or all of the layers may be formed in a batch manner.

Further, the transparent conductive film 1 is provided with the transparent substrate 2, the refractive index adjusting layer 3, the adhesion layer 4, and the transparent conductive layer 6 in this order, and the number of inorganic atoms in the vicinity of the upper surface of the refractive index adjusting layer 3 is relative to carbon. The ratio of the number of atoms is less than 0.05. Therefore, the number of inorganic particles is reduced in the vicinity of the upper surface, and the surface of the upper surface of the refractive index adjusting layer 3 and the surface of the transparent conductive layer 6 provided thereon can be made smooth. Therefore, the specific resistance of the transparent conductive layer 6 is lowered, and the resistance can be reduced.

Further, the adhesion layer 4 is in contact with the refractive index adjustment layer 3. Therefore, the refractive index adjusting layer 3 is firmly adhered to the adhesion layer 4, and the refractive index adjustment layer 3 is in close contact with the optical adjustment layer 5 or the transparent conductive layer 6 via the adhesion layer 4. Therefore, even under particularly harsh conditions, specifically, even after exposure to an environment of 85 ° C and 85% for 150 hours or more, preferably 200 hours or more, more preferably 240 hours or more, the resin-containing layer can be suppressed ( The interlayer between the refractive index adjusting layer 3) and the inorganic layer (the optical adjustment layer 5 or the transparent conductive layer 6) is easily peeled off. As a result, interlayer peeling or even breakage in the transparent conductive film 1 can be suppressed.

Therefore, according to the transparent conductive film 1, it is possible to suppress breakage of the film and to provide Since it has good electrical conductivity characteristics, it can suppress the reduction of various functions such as the sensitivity of the touch panel even when used as a substrate for a large or thin touch panel.

The transparent conductive film 1 can be used, for example, for a substrate for a touch panel provided in an image display device. Examples of the touch panel include various methods such as an optical method, an ultrasonic method, a capacitive method, and a resistive film method, and can be preferably used for a capacitive touch panel.

(variation)

In the embodiment of FIG. 1, the transparent conductive film 1 includes a transparent substrate 2, a refractive index adjusting layer 3, an adhesion layer 4, an optical adjustment layer 5, and a transparent conductive layer 6, for example, a transparent conductive film as shown in FIG. 1 may include a transparent substrate 2, a refractive index adjusting layer 3, an adhesion layer 4, and a transparent conductive layer 6.

That is, the transparent conductive film 1 of FIG. 2 includes the transparent substrate 2, the refractive index adjusting layer 3 disposed on the transparent substrate 2, the adhesion layer 4 disposed on the refractive index adjusting layer 3, and the adhesion layer 4 The transparent conductive layer 6 does not have the optical adjustment layer 5.

Further, in the embodiment of Fig. 1, the refractive index adjusting layer 3 is brought into contact with the upper surface of the transparent substrate 2, but the invention is not limited thereto. For example, the refractive index adjusting layer 3 may not be brought into contact with the upper surface of the transparent substrate 2, and other layers may be interposed therebetween, but are not shown.

Further, for example, a refractive index having a refractive index lower than that of the optical refractive adjustment layer 5 or a refractive index lower or higher may be laminated on the upper surface and/or the lower surface of the optical adjustment layer 5, but not shown.

In the present invention, from the viewpoint of suppressing the visibility of the wiring pattern, etc., the transparent conductive film 1 of Fig. 1 is preferably used.

[Examples]

Hereinafter, the present invention will be further specifically described by way of examples and comparative examples. Further, the present invention is not limited by the examples and the comparative examples. Further, the specific values such as the blending ratio (content ratio), physical property values, and parameters used in the following descriptions may be replaced by The above-mentioned ratios (content ratios), physical property values, and parameters described in the "Embodiment" are described as upper limit values (defined as "below", "not reached") or lower limit ( Defined as "above" and "exceeded" values).

Example 1

(transparent substrate)

As the transparent substrate, a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Plastics, Inc., trade name "DIAFOIL", thickness: 100 μm) was used.

(Formation of refractive index adjustment layer)

A dispersion obtained by dispersing zirconium oxide (ZrO ₂ ) particles (average particle diameter: 20 nm) in methyl ethyl ketone and an ultraviolet curable acrylic resin are mixed, and the solid content concentration is 5% by mass. A dilution of the ultraviolet curable resin composition was prepared by diluting with methyl ethyl ketone. In the case where the total amount of the ultraviolet curable acrylic resin and the zirconia particles is 100% by mass, the composition of the ultraviolet curable resin composition is 25 mass% of the ultraviolet curable acrylic resin. The zirconia particles were adjusted in such a manner as to be 75 mass%.

Then, the diluted solution was applied to the upper surface of the PET film so as to have a thickness of 300 nm after drying, and dried by heating at 80 ° C for 3 minutes. Thereafter, ultraviolet rays having an integrated light amount of 300 mJ/cm ^{2 were} irradiated by a high pressure mercury lamp to form a refractive index adjusting layer. That is, a transparent substrate is obtained. The refractive index adjustment layer laminate body.

The refractive index adjusting layer has a refractive index of 1.65 and a ratio of Zr/C in the vicinity of the upper surface of 0.02 (measurement method will be described later).

(formation of the adhesion layer)

Then, oxygen gas (O ₂ ) was introduced while introducing a pressure of 0.3 Pa in Ar, and sputtering was performed under the following conditions to form an adhesion layer on the upper surface of the refractive index adjusting layer.

Power: AC intermediate frequency (AC/MF) power supply

Target: Si (manufactured by Mitsui Mining & Mining Co., Ltd.)

Gas flow ratio: Ar: O ₂ = 100: 0.1. Further, when the adhesion layer is formed, the lower surface of the PET film (the side opposite to the surface on which the refractive index adjusting layer is formed) is brought into contact with -5 ° C The film forming roll was carried out while cooling the PET film.

The obtained adhesion layer was a germanium compound layer having a bonding energy of Si 2p orbital of 102.2 eV and a thickness of 2 nm. Furthermore, the adhesion layer has a refractive index of 1.74.

(formation of optical adjustment layer)

Then, oxygen gas (O ₂ ) was introduced while introducing a pressure of 0.2 Pa in Ar, and sputtering was performed under the following conditions to form an optical adjustment layer on the upper surface of the adhesion layer.

Power: AC intermediate frequency (AC/MF) power supply

Target: Si (manufactured by Mitsui Mining & Mining Co., Ltd.)

Gas flow ratio: Ar:O ₂ =100:41

The obtained optical adjustment layer was a SiO ₂ layer having a thickness of 14 nm.

(formation of transparent conductive layer)

Sputtering was carried out under the following conditions, and a first transparent conductive layer containing an indium tin oxide layer having a thickness of 15 nm was formed on the upper surface of the optical adjustment layer.

Air pressure: 0.4Pa

Gas ratio: Ar and O ₂ (flow ratio Ar: O ₂ = 99:1)

Power: DC (DC) power supply

Target: sintered body of tin oxide (10% by mass) and indium oxide (90% by mass)

Then, sputtering was performed under the following conditions, and a second transparent conductive layer containing an indium tin oxide layer having a thickness of 7 nm was formed on the upper surface of the first transparent conductive layer.

Air pressure: 0.3Pa

Gas ratio: Ar and O ₂ (flow ratio Ar: O ₂ = 99:1)

Power: DC (DC) power supply

Target: sintered body of tin oxide (3 mass%) and indium oxide (97 mass%)

Gas flow ratio: Ar:O ₂ =99:1

Thus, an amorphous ITO layer (22 nm) including a laminate of the first transparent conductive layer and the second transparent conductive layer was formed on the upper surface of the optical adjustment layer.

(crystallization conversion treatment)

Then, the film in which the amorphous ITO layer was formed was heat-treated in an oven at 140 ° C for 60 minutes to form a crystalline ITO layer (thickness: 22 nm) as a transparent conductive layer. The heat-treated transparent conductive layer was immersed in hydrochloric acid (concentration: 5 mass%) at 20 ° C for 15 minutes, washed with water, dried, and the inter-terminal resistance at intervals of about 15 mm was measured to confirm that the ITO layer was crystallized. quality. Thus, the transparent conductive film of Example 1 was produced (see FIG. 1).

Example 2

In the formation of the refractive index adjusting layer, the composition of the ultraviolet curable resin composition is adjusted so as to be 22% by mass of the ultraviolet curable acrylic resin and 78% by mass of the zirconia particles, and the zirconium atom in the vicinity of the upper surface is opposite to the carbon. A refractive index adjusting layer (refractive index 1.67) was formed in the same manner as in Example 1 except that the atomic ratio (Zr/C) was adjusted to be 0.04.

In the same manner as in the first embodiment, the flow ratio of Ar to O ₂ was set to Ar:O ₂ =100:0.3, and the thickness of the adhesion layer was set to 3 nm. An adhesion layer is formed (the bond energy of the Si2p track is 102.5 eV).

Thus, the transparent conductive film of Example 2 was produced.

Example 3

In the formation of the adhesion layer, the adhesion layer was formed in the same manner as in Example 1 except that the O _{2 was} not introduced and the thickness of the adhesion layer was changed to 3 nm (the bonding energy of the Si 2p orbital was 101.6 eV).

Thus, the transparent conductive film of Example 3 was produced.

Example 4

In the formation of the adhesion layer, the adhesion layer was formed in the same manner as in Example 1 except that O _{2 was} not introduced and the thickness of the adhesion layer was formed to be 10 nm (the bonding energy of the Si 2p orbital was 98.9 eV). .

Thus, the transparent conductive film of Example 4 was produced.

Example 5

In the formation of the adhesion layer, the flow ratio of Ar to O ₂ was set to Ar:O ₂ =100:25, and the thickness of the adhesion layer was set to 10 nm, and the adhesion was formed in the same manner as in Example 1. Layer (bonding energy of Si2p orbital is 103.1 eV).

Thus, the transparent conductive film of Example 5 was produced.

Comparative example 1

In the formation of the refractive index adjusting layer, the composition of the refractive index adjusting layer is adjusted so as to be 15% by mass of the ultraviolet curable acrylic resin and 85% by mass of the zirconia particles, and the zirconium atom in the vicinity of the upper surface is opposite to the carbon atom. The ratio is adjusted in such a manner that (Zr/C) becomes 0.09. Further, the thickness of the refractive index adjusting layer was changed to 1.1 μm. A refractive index adjusting layer (refractive index layer 1.75) was formed in the same manner as in Example 1 except for the above changes.

Further, in the formation of the adhesion layer, the adhesion layer was formed in the same manner as in Example 1 except that O _{2 was} not introduced and the thickness of the adhesion layer was 3 nm (the bond energy of Si 2p orbit was 102.8 eV). .

Thus, the transparent conductive film of Comparative Example 1 was produced.

Further, the transparent conductive layer after the heat treatment was immersed in hydrochloric acid by the same method as in Example 1, and it was confirmed that the ITO layer was not completely converted into crystalline form.

Comparative example 2

A transparent conductive film of Comparative Example 2 was produced in the same manner as in Example 1 except that the adhesion layer was not formed.

(1) Thickness of each layer

The thicknesses of the refractive index adjusting layer, the adhesion layer, the optical adjustment layer, and the transparent conductive layer were measured by a cross-sectional observation using a transmission electron microscope ("H-7650" manufactured by Hitachi, Ltd.). The thickness of the transparent substrate was measured using a film thickness meter (Digital Dial Gauge DG-205 manufactured by Peacock Co., Ltd.). The results are shown in Table 1.

(2) Refractive index of the refractive index adjusting layer, the adhesion layer and the optical adjustment layer

The refractive index was obtained by forming a refractive index adjusting layer, an adhesion layer, or an optical adjustment layer, and then using a high-speed spectral ellipsometer (manufactured by JA Woollam Co., Ltd., M-2000DI) to reflect light from the measurement sample. The change in the polarization state is measured, and the acquired data is calculated using the analysis software WVASE32. Furthermore, the value of the refractive index of the present specification is the refractive index at a wavelength of 550 nm. The results are shown in Table 1.

(3) Zr/C ratio near the upper surface of the refractive index adjusting layer

For transparent substrates. The surface of the refractive index adjusting layer was etched to a thickness of about 1 nm by X-ray photoelectron spectroscopy (ESCA: Electron Spectroscopy for Chemical Analysis; measuring apparatus: "Quantum 2000"; manufactured by ULVAC-PHI Co., Ltd.) to remove Surface contamination. Then, the elemental ratio (atomic%) of the C atom, the O atom, and the Zr atom is measured on the upper surface after the etching, and the ratio of the number of Zr atoms to the number of C atoms in the region near the upper surface (thickness 0 to 10 nm) is obtained. . The results are shown in Table 1.

(4) Bonding energy of Si2p orbital of the adhesion layer

In the examples 1 to 3 and the comparative example 1, the transparent conductive film of each example was subjected to X-ray photoelectron spectroscopy (the measurement apparatus was the same as described above) under the following conditions, and the depth distribution was obtained, and the adhesion layer was obtained ( The bonding energy of the Si2p orbital from the upper side region of the 1 nm end portion of the adhesion layer).

X-ray source: monochromatic AlKα

X Ray setting: 200μm , 15kV, 30W

Photoelectron grazing angle: 45° relative to the surface of the sample

Charge Neutralization Conditions: Combination of Electronic Neutralizing Gun and Ar Ion Gun (Neutralization Mode)

Bonding energy: Correcting the peak value of the C1s spectrum from the C-C bond to 285.0 eV (only the most surface)

Acceleration voltage of Ar ion gun: 1kV

Ar ion gun etching rate: 2nm / min (SiO ₂ conversion)

In Examples 4 and 5, prepared in a transparent substrate. An adhesion layering film having an adhesion layer formed on the refractive index adjusting layer of the refractive index adjusting layer laminate, and etching the outer surface of the adhesion layer by 2 nm to remove surface contamination, and then by X-ray photoelectron spectroscopy (the measuring device is the same as above) The bond energy of the Si2p orbit is determined. The results are shown in Table 1.

(5) Surface resistance value and specific resistance value of transparent conductive layer

The surface resistance value of the transparent conductive layer was measured in accordance with JIS K 7194 (1994) using a four-terminal method. Further, the value obtained by multiplying the surface resistance value by the thickness (in terms of cm) of the transparent conductive layer is defined as a specific resistance value. The results are shown in Table 1.

(6) Adhesion

The transparent conductive film was exposed to a humidified atmosphere of 85% at 85 ° C for 240 hours, and thereafter, a grid peeling test (1 mm □, 100 squares in total) was carried out in accordance with JIS K 5400, and the bonding was performed in accordance with the following criteria. Sexual evaluation.

The case where the peeling was 0 grid was evaluated as ○.

The case where the peeling was 1 or more and 10 or less was evaluated as Δ.

The case where the peeling was 11 or more was evaluated as ×.

In the present specification, the term "peeling" means a case where 0.25 mm ² or more (1/4 or more of the square area) is peeled off per one cell. The results are shown in Table 1.

(7) Light transmittance

The total light transmittance of the transparent conductive film was measured using a fog meter (Model: HGM-2DP) manufactured by Suga Test Instruments.

The case where the total light transmittance was 90% or more was evaluated as ○.

The case where the total light transmittance was 75% or more and less than 90% was evaluated as Δ.

The case where the total light transmittance was less than 75% was evaluated as ×.

The results are shown in Table 1.

Furthermore, the invention described above is provided as an exemplified embodiment of the invention, which is merely illustrative and not to be construed as limiting. Variations of the invention that are clear to those skilled in the art are included in the scope of the claims described below.

[Industrial availability]

The transparent conductive film of the present invention can be used in various industrial products, and can be preferably used, for example, in a film for a touch panel incorporated in an image display device.

1‧‧‧Transparent conductive film

2‧‧‧Transparent substrate

3‧‧‧Refractive index adjustment layer

4‧‧ ‧ close layer

5‧‧‧Optical adjustment layer

6‧‧‧Transparent conductive layer

Claims (7)

A transparent conductive film comprising, in the thickness direction, a transparent substrate, a refractive index adjusting layer containing a resin and inorganic particles, an adhesive layer containing an inorganic atom, and a transparent conductive layer, wherein the adhesion layer and the adhesion layer The refractive index adjusting layer is in contact with the ratio of the number of inorganic atoms to the number of carbon atoms in the vicinity of the interface of the refractive index adjusting layer on the side in contact with the adhesion layer. The transparent conductive film of claim 1, wherein the adhesion layer contains an inorganic compound having a non-stoichiometric composition. The transparent conductive film of claim 2, wherein the inorganic compound having the non-stoichiometric composition is a non-stoichiometric composition of a ruthenium compound. The transparent conductive film of claim 1, wherein the adhesion layer contains a ruthenium atom, and the bonding energy of the Si 2p orbital determined by X-ray photoelectron spectroscopy is 99.0 eV or more and less than 103.0 eV. The transparent conductive film of claim 1, further comprising an optical adjustment layer containing an inorganic oxide between the adhesion layer and the transparent conductive layer. The transparent conductive film of claim 1, wherein the transparent conductive layer has a surface resistance value of less than 200 Ω/□. The transparent conductive film of claim 1, wherein the transparent conductive layer has a specific resistance value of 3.7×10 ^-4 Ω. Below cm.