TW202042255A - Light transmissive conductive film capable of etching a light transmissive conductive layer in a short time - Google Patents

Abstract

The present invention provides a light transmissive conductive film capable of etching a light transmissive conductive layer in a short time. The light transmissive conductive film 1 of the present invention includes a transparent substrate 2, and a light transmissive conductive layer 5 disposed at an upper side of the transparent substrate 2. If a carrier density in the light transmissive conductive layer 5 is set as n*10<SP>19</SP> (/cm 3) and a Hall mobility is set as [mu] (cm 2 /V.s), a ratio (n/ [mu]) of n against [mu] is over 5.0.

Description

Transparent conductive film

The present invention relates to a light-transmitting conductive film, and in detail, to a light-transmitting conductive film that is preferably used for optical applications.

Previously, a transparent conductive film provided with a transparent conductive layer was used as a substrate for touch panels in an image display device, etc. For example, Patent Document 1 discloses a transparent conductive film provided with a polymer film and a transparent conductive layer containing an indium-tin composite oxide.

Generally, in order to be used as a substrate for a touch panel, the transparent conductive layer is patterned into a desired pattern (for example, an electrode pattern or a wiring pattern) of the touch input area by etching. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-71850

[The problem to be solved by the invention]

However, in the transparent conductive film of Patent Document 1, there is a disadvantage that the etching speed of the transparent conductive layer is relatively slow. That is, the etching properties are poor. Therefore, the productivity of the touch panel substrate with the required pattern is poor.

The present invention is to provide a translucent conductive film that can etch a translucent conductive layer at an excellent speed. [Technical means to solve the problem]

The present invention [1] includes a light-transmitting conductive film comprising a transparent substrate, and a light-transmitting conductive layer disposed on one side of the transparent substrate in the thickness direction, and the carrier in the light-transmitting conductive layer When the density is set to n×10 ¹⁹ (/cm ³ ) and the Hall mobility (Hall mobility) is set to μ(cm ² /V·s), the ratio of n to μ (n/μ) exceeds 5.0.

The present invention [2] includes the translucent conductive film described in [1], wherein the above-mentioned ratio (n/μ) is 5.1 or more.

The present invention [3] includes the translucent conductive film described in [1] or [2], wherein the translucent conductive layer contains an indium-based inorganic oxide.

The present invention [4] includes the translucent conductive film described in [3], wherein the translucent conductive layer includes, in the thickness direction, a first region in which the mass ratio of an impurity inorganic element to indium is 0.05 or more, and an impurity inorganic The second region where the mass ratio of the element to indium does not reach 0.05.

The present invention [5] includes the transparent conductive film described in any one of [1] to [4], wherein the carrier density of the transparent conductive layer is 50×10 ¹⁹ (/cm ³ ) or more, 170 ×10 ¹⁹ (/cm ³ ) or less, the Hall mobility is 5 (cm ² /V·s) or more and 40 (cm ² /V·s) or less.

The present invention [6] includes the translucent conductive film described in any one of [1] to [5], wherein the translucent conductive layer is patterned. [Effects of Invention]

According to the light-transmitting conductive film of the present invention, the light-transmitting conductive layer can be etched at an excellent speed, and the productivity is excellent.

<One embodiment> 1 to 2, an embodiment of the transparent conductive film 1 of the present invention will be described.

In Figure 1, the up and down direction on the paper is the up and down direction (thickness direction, the first direction), the upper side of the paper is the upper side (thickness direction one side, the first direction side), and the lower side of the paper is the lower side (the other side thickness direction) , The other side of the first direction). In addition, the left-right direction and the depth direction on the paper surface are plane directions orthogonal to the up-down direction. Specifically, according to the direction arrows in each figure.

1. Translucent conductive film The translucent conductive film 1 has a film shape (including a sheet shape) having a specific thickness, extends in a specific direction (plane direction) orthogonal to the thickness direction, and has a flat upper surface and a flat lower surface. The light-transmitting conductive film 1 is, for example, a part such as a substrate for a touch panel included in an image display device, that is, it is not an image display device. That is, the light-transmitting conductive film 1 is used to make parts for image display devices, etc., does not include image display elements such as LCD (Liquid Crystal Display) modules, and includes the following transparent substrate 2. Hard coat layer 3. The optical adjustment layer 4 and the light-transmitting conductive layer 5 are parts that are circulated separately and are industrially available devices.

Specifically, as shown in FIG. 1, the translucent conductive film 1 includes a transparent substrate 2, a hard coat layer 3 arranged on the upper surface (one surface in the thickness direction) of the transparent substrate 2, and a hard coat layer 3 arranged on The optical adjustment layer 4 on the surface and the translucent conductive layer 5 arranged on the upper surface of the optical adjustment layer 4. More specifically, the translucent conductive film 1 includes a transparent substrate 2, a hard coat layer 3, an optical adjustment layer 4, and a translucent conductive layer 5 in this order. The light-transmitting conductive film 1 is preferably composed of a transparent substrate 2, a hard coat layer 3, an optical adjustment layer 4, and a light-transmitting conductive layer 5. In addition, the light-transmitting conductive film 1 is a transparent conductive film.

2. Transparent substrate The transparent substrate 2 is a transparent substrate for ensuring the mechanical strength of the transparent conductive film 1. That is, the transparent base material 2 supports the translucent conductive layer 5 together with the hard coat layer 3 and the optical adjustment layer 4.

The transparent substrate 2 is the lowermost layer of the translucent conductive film 1 and has a film shape. The transparent substrate 2 is arranged on the entire lower surface of the hard coat layer 3 so as to be in contact with the lower surface of the hard coat layer 3.

Examples of the transparent substrate 2 include a polymer film and an inorganic plate (glass plate, etc.). From the viewpoint of having both transparency and flexibility, a polymer film is preferably used.

As the material of the polymer film, for example, polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, etc.; for example, polymethacrylate (Meth)acrylic resins (acrylic resins and/or methacrylic resins); for example, olefin resins such as polyethylene, polypropylene, and cycloolefin polymers; for example, polycarbonate resins, polyether turpentine resins, polyarylate resins, Melamine resin, polyamide resin, polyimide resin, cellulose resin, polystyrene resin, etc. These polymer films can be used alone or in combination of two or more kinds.

Regarding the transparent substrate 2, from the viewpoints of transparency, flexibility, mechanical strength, etc., preferably, a polyethylene terephthalate film and a cycloolefin polymer film are mentioned.

The total light transmittance (JIS K 7375-2008) of the transparent substrate 2 is, for example, 80% or more, preferably 85% or more.

Regarding the thickness of the transparent substrate 2, from the viewpoints of mechanical strength and dot characteristics when the light-transmitting conductive film 1 is used as a film for a touch panel, it is, for example, 2 μm or more, preferably 20 μm or more, and, for example, It is 300 μm or less, preferably 150 μm or less. The thickness of the transparent base material 2 can be measured using a micrometer type thickness meter, for example.

A spacer or the like may also be provided on the lower surface of the transparent substrate 2.

3. Hard coating The hard coat layer 3 is a protective layer for suppressing damage to the transparent substrate 2 when the transparent conductive film 1 is manufactured. In addition, when a plurality of light-transmitting conductive films 1 are laminated, the hard coat layer 3 is a scratch-resistant layer for suppressing scratches on the light-transmitting conductive layer 5.

The hard coat layer 3 has a film shape. The hard coat layer 3 is arranged on the entire upper surface of the transparent substrate 2 so as to be in contact with the upper surface of the transparent substrate 2. More specifically, the hard coat layer 3 is arranged between the transparent substrate 2 and the optical adjustment layer 4 so as to be in contact with the upper surface of the transparent substrate 2 and the lower surface of the optical adjustment layer 4.

The hard coat layer 3 is formed of a hard coat composition. The hard coating composition contains resin, and is preferably composed of resin.

Examples of the resin include curable resins, thermoplastic resins (for example, polyolefin resins), and the like, and preferably curable resins.

Examples of curable resins include active energy ray curable resins that are cured by irradiation with active energy rays (specifically, ultraviolet rays, electron beams, etc.), such as thermosetting resins that are cured by heating, and the like, preferably Examples of active energy ray-curable resins.

Examples of the active energy ray curable resin include polymers having a functional group having a polymerizable carbon-carbon double bond in the molecule. As such a functional group, a vinyl group, a (meth)acryloyl group (methacryloyl group and/or an acryloyl group) etc. are mentioned, for example.

Specific examples of active energy ray-curable resins include (meth)acrylic ultraviolet-curable resins such as acrylic urethane and epoxy acrylate.

In addition, examples of curable resins other than active energy ray curable resins include thermosetting resins such as polyurethane resins, melamine resins, alkyd resins, silicone polymers, and organosilane condensates.

The resin can be used alone or in combination of two or more kinds.

The hard coating composition may also contain particles. Thereby, the hard coating layer 3 can be an anti-blocking layer with anti-blocking properties.

Examples of particles include inorganic particles, organic particles, and the like. As the inorganic particles, for example, silica particles; for example, metal oxide particles containing zirconium oxide, titanium oxide, zinc oxide, tin oxide, etc.; for example, carbonate particles such as calcium carbonate. Examples of organic particles include crosslinked acrylic resin particles. The particles can be used alone or in combination of two or more kinds.

The hard coating composition may further contain well-known additives such as a leveling agent, a thixotropic agent, and an antistatic agent.

Regarding the thickness of the hard coat layer 3, from the viewpoint of scratch resistance, it is, for example, 0.1 μm or more, preferably 0.5 μm or more, and, for example, 10 μm or less, preferably 3 μm or less. The thickness of the hard coat layer 3 can be measured by cross-sectional observation using a transmission electron microscope, for example.

4. Optical adjustment layer The optical adjustment layer 4 is a layer that adjusts the optical properties (for example, refractive index) of the transparent conductive film 1 in order to suppress the visibility of the pattern of the transparent conductive layer 5 and ensure excellent transparency of the transparent conductive film 1.

The optical adjustment layer 4 has a film shape. The optical adjustment layer 4 is arranged on the entire upper surface of the hard coat layer 3 so as to be in contact with the upper surface of the hard coat layer 3. More specifically, the optical adjustment layer 4 is arranged between the hard coat layer 3 and the transparent conductive layer 5 so as to be in contact with the upper surface of the hard coat layer 3 and the lower surface of the transparent conductive layer 5.

The optical adjustment layer 4 is formed of an optical adjustment composition. The optical adjustment composition contains resin, and preferably contains resin and particles.

The resin is not particularly limited, and examples thereof include resins exemplified in the hard coat composition. Preferably, a curable resin is used, more preferably, an active energy ray curable resin is used, and still more preferably, a (meth)acrylic ultraviolet curable resin is used.

The resin content relative to the optical adjustment composition is, for example, 10% by mass or more, preferably 25% by mass or more, and, for example, 95% by mass or less, and preferably 60% by mass or less.

As the particles, a preferable material can be selected according to the refractive index required for the optical adjustment layer. For example, the particles exemplified in the hard coat composition can be cited. From the viewpoint of refractive index, preferably, inorganic particles are used, more preferably, metal oxide particles are used, and still more preferably, zirconium oxide particles (ZrO ₂ ) are used.

The content ratio of the particles relative to the optical adjustment composition is, for example, 5% by mass or more, preferably 40% by mass or more, and, for example, 90% by mass or less, preferably 75% by mass or less.

The optical adjustment composition may further contain well-known additives such as a leveling agent, a thixotropic agent, and an antistatic agent.

The refractive index of the optical adjustment layer 4 is, for example, 1.40 or more, preferably 1.55 or more, for example, 1.80 or less, preferably 1.70 or less. The refractive index can be measured with an Abbe refractometer, for example.

The thickness of the optical adjustment layer 4 is, for example, 5 nm or more, preferably 10 nm or more, and, for example, 200 nm or less, preferably 100 nm or less. The thickness of the optical adjustment layer 4 can be measured by cross-sectional observation using a transmission electron microscope, for example.

5. Translucent conductive layer The light-transmitting conductive layer 5 is used as a transparent conductive layer formed into a desired pattern (for example, an electrode pattern or a wiring pattern) by etching.

The light-transmitting conductive layer 5 is the uppermost layer of the light-transmitting conductive film 1 and has a film shape. The translucent conductive layer 5 is arranged on the entire upper surface of the optical adjustment layer 4 so as to be in contact with the upper surface of the optical adjustment layer 4.

Examples of the material of the light-transmitting conductive layer 5 include indium-based inorganic oxides, antimony-based inorganic oxides, and the like, and preferably, indium-based inorganic oxides are used.

The material of the translucent conductive layer 5 preferably contains (doped) selected from Sn, Zn, Ga, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, W, Fe, Pb, At least one impurity inorganic element in the group consisting of Ni, Nb, and Cr. As the impurity inorganic element, Sn is preferable.

As the inorganic oxide containing impurity inorganic elements, for example, in the case of indium-based inorganic oxides, indium tin composite oxide (ITO) can be cited, and for example, in the case of antimony-based inorganic oxides, antimony tin composite oxides can be cited. (ATO). Preferably, ITO is mentioned.

When the translucent conductive layer 5 is formed of ITO, in the entire translucent conductive layer 5, the content of tin oxide (SnO ₂ ) relative to the total amount of tin oxide and indium oxide (In ₂ O ₃ ) is, for example, 0.5% by mass or more, preferably 3% by mass or more, and, for example, 15% by mass or less, preferably 13% by mass or less.

The light-transmitting conductive layer 5 may include a single layer, or may include multiple layers (thickness direction regions). The number of layers is not limited, and for example, two or more layers and five or less layers are exemplified, preferably two layers are used.

Preferably, the light-transmitting conductive layer 5 includes a plurality of layers.

Specifically, as shown by the imaginary line in FIG. 1, for example, the light-transmitting conductive layer 5 includes a first layer (an example of the first region) 5a, and a second layer (second layer) arranged on the upper side of the first layer 5a. Example of area) 5b.

The first layer 5a and the second layer 5b are preferably both formed of an inorganic oxide containing an impurity inorganic element, preferably both are formed of an indium-based inorganic oxide containing an impurity inorganic element, and more preferably both are formed of ITO.

Moreover, in this case, the mass ratio of the impurity inorganic element (preferably Sn) of the layer farthest from the transparent substrate 2 (ie, the second layer 5b) to indium is higher than that of the plurality of layers ( That is, among the first layer 5a and the second layer 5b), it is preferably not the largest, and more preferably the smallest. That is, when the translucent conductive layer 5 includes the first layer 5a and the second layer 5b, the mass ratio of the impurity inorganic element to indium in the second layer 5b is smaller than that of the impurity inorganic element in the first layer 5a to indium. Quality ratio.

Specifically, it is preferable that the mass ratio of the impurity inorganic element to indium in the first layer 5a is 0.05 or more, and the mass ratio of the impurity inorganic element to indium in the second layer 5b is preferably less than 0.05. Thereby, the crystal transition of the translucent conductive layer 5 can be performed more reliably in a short time.

More specifically, when the first layer 5a is formed of ITO, the content of tin oxide (SnO ₂ ) in the first layer 5a relative to the total amount of tin oxide and indium oxide (In ₂ O ₃ ) is, for example, 5 mass% or more, preferably 8 mass% or more, and, for example, 15 mass% or less, preferably 13 mass% or less. The content of tin oxide in the first layer 5a can improve transparency or stability of surface resistance.

When the second layer 5b is formed of ITO, the content of tin oxide (SnO ₂ ) in the second layer 5b relative to the total amount of tin oxide and indium oxide (In ₂ O ₃ ) is, for example, 0.5% by mass or more, It is preferably 2% by mass or more, and, for example, less than 8% by mass, and more preferably less than 5% by mass. If the content of tin oxide in the second layer 5b is within the above range, the crystal transition of the translucent conductive layer 5 can be easily performed, and the conductivity can be reliably improved.

The ratio in the thickness direction of the first layer 5a in the translucent conductive layer 5 is, for example, 75% or more, preferably 80% or more, more preferably 90% or more, and, for example, 99% or less, preferably 98 % Or less, more preferably 97% or less. Specifically, the thickness of the first layer 5a is, for example, 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more, and, for example, 200 nm or less, preferably 150 nm or less, more preferably 50 nm the following.

The ratio in the thickness direction of the second layer 5b in the translucent conductive layer 5 is, for example, 25% or less, preferably 20% or less, more preferably 10% or less, for example, 1% or more, preferably 2% or more , More preferably 3% or more. Also, specifically, the thickness of the second layer 5b is, for example, 1 nm or more, preferably 1.5 nm or more, more preferably 2 nm or more, and, for example, 40 nm or less, preferably 20 nm or less, and more preferably Below 10 nm.

The total thickness of the translucent conductive layer 5 is, for example, 10 nm or more, preferably 20 nm or more, more preferably 35 nm or more, and, for example, 300 nm or less, preferably 180 nm or less, and more preferably 100 nm or less . The thickness of the light-transmitting conductive layer 5 can be measured by cross-sectional observation using a transmission electron microscope, for example.

The translucent conductive layer 5 may be crystalline or amorphous, but from the viewpoint of good conductivity and etching properties, it is preferably crystalline.

Regarding whether the translucent conductive layer is amorphous or crystalline, for example, when the translucent conductive layer is an ITO layer, it can be carried out by immersing in hydrochloric acid (concentration 5 mass%) at 20°C for 15 minutes. Wash with water, dry, and judge by measuring the resistance between terminals about 15 mm. In this manual, when immersed in hydrochloric acid (20°C, concentration: 5 mass%), washed with water, and dried, when the resistance between the terminals between 15 mm exceeds 10 kΩ, the ITO layer is made amorphous. When the resistance between the terminals between 15 mm is 10 kΩ or less, the ITO layer shall be crystalline.

6. Manufacturing method of translucent conductive film Next, the method of manufacturing the translucent conductive film 1 is demonstrated. In order to manufacture the light-transmitting conductive film 1, for example, a hard coat layer 3, an optical adjustment layer 4, and a light-transmitting conductive layer 5 are sequentially provided on the upper surface of the transparent substrate 2 (one side in the thickness direction). Hereinafter, a detailed description will be given.

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

Thereafter, if necessary, from the viewpoint of the adhesion between the transparent substrate 2 and the hard coat layer 3, the transparent substrate 2 may be subjected to, for example, sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, and chemical treatment. , Oxidation and other etching treatment or primer treatment. In addition, the transparent substrate 2 can be dust-removed and purified by solvent cleaning, ultrasonic cleaning, or the like.

Then, a hard coat layer 3 is provided on the upper surface of the transparent substrate 2. For example, by wet-coating the hard coating composition on the upper surface of the transparent substrate 2, the hard coating 3 is formed on the upper surface of the transparent substrate 2.

Specifically, for example, a solution (varnish) obtained by diluting the hard coating composition with a solvent is prepared, and then the hard coating composition solution is applied to the upper surface of the transparent substrate 2 and dried.

As a solvent, an organic solvent, an aqueous solvent (specifically water), etc. are mentioned, for example, Preferably, an organic solvent is mentioned. Examples of organic solvents include alcohol compounds such as methanol, ethanol, and isopropanol; ketone compounds such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and ester compounds such as ethyl acetate and butyl acetate; Ether compounds such as propylene glycol monomethyl ether; for example, aromatic compounds such as toluene and xylene. These solvents can be used alone or in combination of two or more kinds.

The solid content concentration in the hard coat composition solution is, for example, 1% by mass or more, preferably 10% by mass or more, and, for example, 30% by mass or less, preferably 20% by mass or less.

The coating method can be appropriately selected according to the hard coating composition solution and the transparent substrate 2. Examples of the coating method include dip coating, air knife coating, curtain coating, roll coating, wire bar coating, gravure coating, and extrusion coating.

The drying temperature is, for example, 50°C or higher, preferably 70°C or higher, for example, 200°C or lower, preferably 100°C or lower.

The drying time is, for example, 0.5 minutes or more, preferably 1 minute or more, for example, 60 minutes or less, and preferably 20 minutes or less.

After that, when the hard coat composition contains an active energy ray curable resin, the active energy ray curable resin is cured by irradiating the hard coat composition solution with active energy rays.

Furthermore, when the hard coating composition contains a thermosetting resin, the drying step can be used to dry the solvent and heat the thermosetting resin.

Next, an optical adjustment layer 4 is provided on the upper surface of the hard coat layer 3. For example, by wet-coating the optical adjustment composition on the upper surface of the hard coat layer 3, the optical adjustment layer 4 is formed on the upper surface of the hard coat layer 3.

Specifically, for example, a solution (varnish) obtained by diluting the optical adjustment composition with a solvent is prepared, and then the optical adjustment composition solution is applied to the upper surface of the hard coat layer 3 and dried.

The conditions for preparation, coating, and drying of the optical adjustment composition may be the same as the conditions for preparation, coating, and drying exemplified in the hard coating composition.

Moreover, when the optical adjustment composition contains an active energy ray curable resin, the active energy ray curable resin is cured by irradiating the active energy ray after the optical adjustment composition solution is dried.

Furthermore, when the optical adjustment composition contains a thermosetting resin, the drying step may be used to dry the solvent and heat the thermosetting resin.

Then, a translucent conductive layer 5 is provided on the upper surface of the optical adjustment layer 4. For example, a light-transmitting conductive layer 5 is formed on the upper surface of the optical adjustment layer 4 by a dry method.

As a dry method, a vacuum vapor deposition method, a sputtering method, an ion plating method, etc. are mentioned, for example. Preferably, a sputtering method is mentioned. This method can be used to form the transparent conductive layer 5 of the thin film.

Examples of the sputtering method include a two-pole sputtering method, an ECR (electron cyclotron resonance) sputtering method, a magnetron sputtering method, an ion beam sputtering method, and the like. Preferably, a magnetron sputtering method can be cited.

The power supply used in the sputtering method can be, for example, a direct current (DC) power supply, an alternating current intermediate frequency (AC/MF) power supply, a high frequency (RF (radio frequency, radio frequency)) power supply, and a high frequency power supply obtained by superimposing DC power supplies. Any of them.

In the case of using the sputtering method, as the target material, the above-mentioned inorganic substance constituting the translucent conductive layer 5 may be mentioned, preferably ITO. Regarding the tin oxide concentration of ITO, from the viewpoint of durability and crystallization of the ITO layer, it is, for example, 0.5% by mass or more, preferably 3% by mass or more, and, for example, 15% by mass or less, preferably 13% by mass %the following.

Examples of sputtering gas include inert gases such as Ar. Furthermore, it is preferable to use a reactive gas such as oxygen in combination. When a reactive gas is used in combination, the flow rate ratio of the reactive gas to the inert gas is, for example, 0.0010 or more and 0.0100 or less.

The sputtering method is implemented under vacuum. Specifically, the pressure during sputtering is, for example, 1 Pa or less, preferably 0.7 Pa or less, and, for example, 0.1 Pa or more, from the viewpoints of suppression of sputtering rate reduction and discharge stability.

Regarding the partial pressure of water, from the viewpoint of increasing the rate of crystal transformation, it is, for example, 10×10 ^-4 Pa or less, and preferably 5×10 ^-4 Pa or less.

In addition, in order to form the required translucent conductive layer 5, a target material or sputtering conditions, etc., can be appropriately set and sputtering may be performed multiple times.

Especially in the present invention, for example, by using a substrate containing a cycloolefin resin as a transparent substrate, the amount of oxygen introduced is adjusted, and it is formed by plural layers (preferably the first layer 5a and the second layer 5b) The light-transmitting conductive layer 5 can preferably produce the light-transmitting conductive film 1 provided with the required light-transmitting conductive layer 5.

Specifically, if an ITO layer is formed as the light-transmitting conductive layer 5 by a sputtering method as an example, the ITO layer obtained by the sputtering method is generally formed as an amorphous ITO layer. In addition, by reducing the amount of oxygen in the film-forming atmosphere, oxygen vacancies are generated in the ITO layer, and an ITO layer that can be crystallized by heating can be obtained. At this time, the amount of oxygen is slightly insufficient to the extent that the ITO layer can be crystallized. In addition, by using a cycloolefin-based resin for the transparent base material 2, the generation of moisture that hinders crystal transformation can be reduced compared with polyethylene terephthalate-based resin. In addition, by forming the translucent conductive layer 5 with a plurality of layers (for example, the first layer 5a and the second layer 5b), a layer (the second layer 5b) that facilitates crystal transformation is provided on the exposed surface (the uppermost surface). Thereby, the translucent conductive layer 5 capable of crystal transformation can be formed at a low temperature in a short time.

More specifically, for example, when a cycloolefin-based film is used as the transparent substrate 2, the horizontal magnetic field strength is set to a high magnetic field strength of 50 mT or more and 200 mT or less (preferably 80 mT or more and 120 mT or less), and When using a DC power supply, the following is the case. When forming the first layer 5a, an ITO target with a higher tin oxide concentration is used, and the flow ratio of oxygen to Ar gas (O ₂ /Ar) is set to, for example, 0.0050 or more and 0.0100 or less, preferably 0.0070 or more and 0.0090 or less In addition, the flow rate ratio to the thickness (nm) of ITO is "(O ₂ /Ar)/(ITO thickness)" set to, for example, 0.00010 or more and 0.00020 or less.

Furthermore, regarding whether oxygen is introduced at an appropriate ratio (a slightly insufficient amount of oxygen) in the ITO film formation environment, for example, the oxygen supply amount (sccm) (X-axis) can be plotted on the graph, and based on the oxygen supply amount The surface resistance (Ω/□) (Y axis) of the obtained ITO is judged according to the graph. That is, since the surface resistance of the extremely small area (bottom area) of the graph is the smallest, and the ITO becomes a stoichiometric composition, it can be judged that the value of the X-axis slightly closer to the origin than the extremely small area is suitable for making the transparency of the present invention. The amount of oxygen supplied to the photoconductive layer 5.

Thereby, the transparent conductive film 1 provided with the transparent base material 2, the hard coat layer 3, the optical adjustment layer 4, and the transparent conductive layer 5 in this order in the thickness direction is obtained.

Furthermore, in the above-mentioned manufacturing method, a roll-to-roll method may be used to transport the transparent substrate 2 while forming the hard coat layer 3, the optical adjustment layer 4, and the light-transmitting conductive layer 5 on the transparent substrate 2, or, Part or all of these layers are formed by batch method (single chip method). From the viewpoint of productivity, it is preferable to form each layer on the transparent substrate 2 while conveying the transparent substrate 2 by a roll-to-roll method.

The light-transmitting conductive film 1 may be heated as needed. Thereby, the translucent conductive layer 5 is crystallized to become crystalline, and conductivity is further improved.

Specifically, the light-transmitting conductive film 1 is subjected to heat treatment under the atmosphere.

The heating treatment can be carried out using an infrared heater, an oven, etc., for example.

The heating temperature is, for example, 100°C or higher, preferably 120°C or higher, and, for example, 200°C or lower, preferably 150°C or lower.

The heating time is appropriately determined according to the heating temperature, and is, for example, 5 minutes or more, preferably 10 minutes or more, and, for example, 120 minutes or less, preferably 100 minutes or less.

The translucent conductive film 1 obtained in this way has the following characteristics.

The carrier density (Xa×10 ¹⁹ /cm ³ ) in the translucent conductive layer 5 is, for example, 50×10 ¹⁹ /cm ³ or more, preferably 100×10 ¹⁹ /cm ³ or more, and more preferably 130×10 ¹⁹ /cm ³ or more, and, for example, 170×10 ¹⁹ /cm ³ or less, preferably 150×10 ¹⁹ /cm ³ or less.

The Hall mobility (Ya cm ² /V·s) in the translucent conductive layer 5 is, for example, 5 cm ² /V·s or more, preferably 10 cm ² /V·s or more, and more preferably 20 cm ² /V·s or more, for example, 40 cm ² /V·s or less, preferably 30 cm ² /V·s or less, and more preferably 23 cm ² /V·s or less.

In addition, when the carrier density is set to n×10 ¹⁹ (/cm ³ ) and the Hall mobility is set to μ(cm ² /V·s), the ratio of n to μ (n/μ) exceeds 5.0 , Preferably 5.1 or more, more preferably 5.5 or more, and still more preferably 6.0 or more. The upper limit is not limited, and is, for example, 20.0 or less, preferably 10.0 or less. If the above-mentioned ratio (n/μ) is at least the above-mentioned lower limit, the light-transmitting conductive layer 5 can be etched into a desired pattern in an excellent short time, and the productivity is excellent.

The surface resistance of the translucent conductive layer 5 is, for example, 1 Ω/□ or more, preferably 10 Ω/□ or more, and, for example, 500 Ω/□ or less, preferably 200 Ω/□ or less. The surface resistance can be measured by the four-terminal method.

The total light transmittance (JIS K 7375-2008) of the light-transmitting conductive film 1 is, for example, 80% or more, preferably 85% or more.

The thickness of the translucent conductive film 1 is, for example, 2 μm or more, preferably 10 μm or more, and, for example, 100 μm or less, preferably 50 μm or less.

The translucent conductive film 1 is arranged in, for example, an optical device. As the optical device, for example, an image display device, a dimming device, etc. can be cited, and preferably, an image display device can be cited. When an image display device (specifically, an image display device having image display elements such as an LCD module) is provided with a light-transmitting conductive film 1, the light-transmitting conductive film 1 is used, for example, for touch panels Substrate. As the form of the touch panel, various methods such as an optical method, an ultrasonic method, an electrostatic capacitance method, and a resistive film method can be cited. In particular, it is preferably used for an electrostatic capacitance method touch panel.

In addition, in the light-transmitting conductive film 1 in the light-transmitting conductive layer 5, the ratio of n to μ (n/μ) exceeds 5.0. Therefore, the light-transmitting conductive layer 5 can be etched at an excellent speed. That is, the translucent conductive layer 5 can be patterned in a short time. Therefore, for example, it is excellent in productivity as a base material for touch panels.

The patterning of the light-transmitting conductive film 1 can employ a known etching. The etching method may be either wet etching or dry etching, but from the viewpoint of production efficiency, wet etching can be cited.

Wet etching is, for example, in a manner corresponding to the patterned portion and the non-patterned portion, the covering portion (masking tape, etc.) is arranged on the translucent conductive layer 5, and the translucent conductive layer exposed from the covering portion is etched using an etchant 5 (Non-pattern part).

Examples of the etching solution include acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, oxalic acid, phosphoric acid, and mixed acids thereof. Thereafter, the coating portion is removed from the upper surface of the crystalline light-transmitting conductive layer 6 by peeling or the like.

The pattern of the light-transmitting conductive layer 5 is appropriately determined according to the application to which the light-transmitting conductive film 1 is applied. For example, an electrode pattern or a wiring pattern having a stripe shape can be cited.

Thereby, the patterned light-transmitting conductive film 1A in which the light-transmitting conductive layer 5 is patterned is mentioned.

＜Change example＞ In the above-mentioned embodiment, the light-transmitting conductive film 1 includes a transparent substrate 2, a hard coat layer 3, an optical adjustment layer 4, and a light-transmitting conductive layer 5. However, the light-transmitting conductive film 1 may further include other than those. The outer layer.

For example, the lower surface of the transparent substrate 2 in one embodiment is exposed, but for example, the translucent conductive film 1 may be further provided with other functional layers such as an anti-blocking layer on the lower surface of the transparent substrate 2.

In addition, the translucent conductive film 1 of one embodiment includes a transparent substrate 2, a hard coat layer 3, an optical adjustment layer 4, and a translucent conductive layer 5. However, for example, the hard coat layer 3 and the optical adjustment layer 4 may not be provided. At least one of them. From the viewpoints of scratch resistance, visibility suppression of the pattern in the light-transmitting conductive layer 5, etc., it is preferable to include the hard coat layer 3 and the optical adjustment layer 4. [Example]

Examples and comparative examples are shown below to further specifically explain the present invention. In addition, the present invention is not limited to any Examples and Comparative Examples. In addition, specific numerical values such as the blending ratio (content ratio), physical property values, and parameters used in the following description can be replaced with the blending ratios (content ratio), physical property values, parameters, etc. corresponding to them described in the above-mentioned "embodiment" Relevant records upper limit (defined as "below", "not reached" value) or lower limit (defined as "above", "over" value).

(Example 1) As a transparent substrate, a cycloolefin polymer (COP) film (manufactured by ZEON, trade name "ZEONOR", thickness 40 μm) was prepared. On the upper surface of the transparent substrate, apply an ultraviolet curable resin composition containing acrylic resin, and irradiate ultraviolet rays to form a hard coat layer (thickness 1 μm). Then, an ultraviolet curable composition containing zirconia particles was coated on the upper surface of the hard coat layer, and ultraviolet rays were irradiated to form an optical adjustment layer (thickness 90 nm, refractive index 1.62). Thereby, a laminate having a transparent base material, a hard coat layer, and an optical adjustment layer is obtained.

A vacuum sputtering device was used to form the first layer (thickness 43 nm) containing an indium tin composite oxide (ITO) layer on the upper surface of the optical adjustment layer of the laminate. Specifically, the vacuum sputtering device is evacuated until the partial pressure of water becomes 2.0×10 ^-4 Pa or less, and then a mixed gas of argon and oxygen is introduced (flow ratio: O ₂ /Ar=0.00763, (O ₂ /Ar)/ITO thickness ratio: 0.000178), and DC magnetron sputtering was applied to the laminate in an atmosphere with a pressure of 0.4 Pa. As the target, a sintered body of 10% by mass of tin oxide and 90% by mass of indium oxide was used. Also, set the horizontal magnetic field on the target surface to 100 mT.

Then, the target was changed to a sintered body of 3% by mass of tin oxide/97% by mass of indium oxide, and the flow ratio of the mixed gas of argon and oxygen was set to O ₂ /Ar=0.00160, except that the same as the above Method, sputtering is further performed to form a second layer (thickness 2 nm) on the upper surface of the first layer. Thereby, a transparent conductive layer (transparent conductive layer) with a total thickness of 45 nm is formed on the upper surface of the optical adjustment layer.

Then, it was heated in a hot air oven at 130°C for 90 minutes to transform the translucent conductive layer.

In this way, the translucent conductive film (transparent conductive film) of Example 1 was manufactured.

(Examples 2 to 5 and Comparative Examples 1 to 3) When forming the first layer and the second layer, as shown in Table 1, the thickness of each layer or the gas flow rate ratio was changed, and except that the transparent conductive film was produced in the same manner as in Example 1.

(1) Measurement of thickness Using a transmission electron microscope (manufactured by Hitachi, Ltd., "H-7650"), the thickness of the hard coat layer, the optical adjustment layer, the first layer, and the second layer were measured by cross-sectional observation.

A film thickness meter (manufactured by Peacock, "digital dial gauge DG-205") was used to measure the thickness of the transparent substrate.

(2) The measurement of carrier density and Hall mobility uses a Hall effect measurement system (manufactured by Bio-Rad, "HL5500PC") to measure the Hall mobility of the light-transmitting conductive layer (μ cm ² /V・s). The carrier density (n×10 ¹⁹ /cm ³ ) was calculated using the total thickness of the transparent conductive layer.

(3) Evaluation of etching time The translucent conductive film of each example and each comparative example was immersed in hydrochloric acid with a concentration of 7 wt% and 35°C for a specific time (15 seconds interval), and then washed and dried. Resistance between terminals. At this time, the time when the resistance between the terminals exceeds 50 kΩ or indicates insulation (error, etc.) is the etching end time. The time obtained by dividing the etching time by the value of the translucent conductive layer (the value of the thickness) was calculated as the etching rate per 1 nm thickness.

The case where the etching rate is 20.0 sec/nm or less is evaluated as ◎, the case where the etching rate exceeds 20.0 sec/nm and is 25.0 sec/nm or less is evaluated as 0, and the case where the etching rate exceeds 25.0 seconds is evaluated as ×. The results are shown in Table 1.

In addition, according to each example and each comparative example, the ratio of n to μ (n/μ) is plotted on the horizontal axis, the etching rate is plotted on the vertical axis, and the relational expressions of these are shown in the graph. This figure is shown in FIG. 3.

[Table 1] To ITO thickness (nm) O ₂ /Ar flow ratio (O ₂ /Ar)/ITO thickness ratio Hall mobility μ (cm ² /V・s) Carrier density n (×10 ¹⁹ /cm ³ ) Ratio (n/μ) Etching rate To Level 1 Level 2 Total thickness Level 1 Level 1 Time (sec/nm) determination Example 1 43 2 45 7.63E-03 1.78E-04 20.9 144.0 6.9 16.4 ◎ Example 2 42 2 44 7.80E-03 1.86E-04 21.7 139.2 6.4 16.5 ◎ Example 3 41 - 41 6.33E-03 1.54E-04 22.2 127.0 5.7 20.8 〇 Example 4 29 4 33 5.48E-03 1.89E-04 twenty two 128.6 5.8 21.2 〇 Example 5 42 - 42 6.40E-03 1.52E-04 22.5 125.3 5.6 21.2 〇 Comparative example 1 70 - 70 1.44E-02 2.06E-04 25.7 97.9 3.8 31.4 X Comparative example 2 26 4 30 6.23E-03 2.39E-04 26 121.4 4.7 25.6 X Comparative example 3 54 - 54 1.10E-02 2.04E-04 25.1 104.9 4.2 30.2 X

1: Translucent conductive film 1A: Transparent conductive film 2: Transparent substrate 3: Hard coating 4: Optical adjustment layer 5: Translucent conductive layer 5a: layer 1 5b: Layer 2

Fig. 1 shows a cross-sectional view of an embodiment of the transparent conductive film of the present invention. 2 shows a cross-sectional view of a patterned transparent conductive film obtained by patterning the transparent conductive film shown in FIG. 1. Fig. 3 shows a graph obtained by plotting the relationship between the ratio of n to μ and the etching rate.

1: Translucent conductive film

2: Transparent substrate

3: Hard coating

4: Optical adjustment layer

5: Translucent conductive layer

5a: layer 1

5b: Layer 2

Claims (10)

A light-transmitting conductive film, characterized by having a transparent substrate, and a light-transmitting conductive layer disposed on one side of the transparent substrate in the thickness direction, and setting the carrier density in the light-transmitting conductive layer When it is n×10 ¹⁹ (/cm ³ ) and the Hall mobility is μ(cm ² /V·s), the ratio of n to μ (n/μ) exceeds 5.0. The light-transmitting conductive film of claim 1, wherein the above-mentioned ratio (n/μ) is 5.1 or more. The translucent conductive film according to claim 1, wherein the translucent conductive layer contains an indium-based inorganic oxide. The light-transmitting conductive film according to claim 2, wherein the light-transmitting conductive layer contains an indium-based inorganic oxide. The light-transmitting conductive film of claim 3, wherein the light-transmitting conductive layer has, in the thickness direction, a first region where the mass ratio of the impurity inorganic element to indium is 0.05 or more, and the mass ratio of the impurity inorganic element to indium The second area that is less than 0.05. The light-transmitting conductive film of claim 4, wherein the light-transmitting conductive layer has, in the thickness direction, a first region in which the mass ratio of the impurity inorganic element to indium is 0.05 or more, and the mass ratio of the impurity inorganic element to indium The second area that is less than 0.05. The light-transmitting conductive film of claim 1, wherein the carrier density of the light-transmitting conductive layer is 50×10 ¹⁹ (/cm ³ ) or more and 170×10 ¹⁹ (/cm ³ ) or less, and the Hall mobility is 5(cm ² /V·s) or more, 40(cm ² /V·s) or less. Such as the light-transmitting conductive film of claim 2, wherein the carrier density of the light-transmitting conductive layer is 50×10 ¹⁹ (/cm ³ ) or more and 170×10 ¹⁹ (/cm ³ ) or less, and the Hall mobility is 5(cm ² /V·s) or more, 40(cm ² /V·s) or less. Such as the light-transmitting conductive film of claim 3, wherein the carrier density of the light-transmitting conductive layer is 50×10 ¹⁹ (/cm ³ ) or more and 170×10 ¹⁹ (/cm ³ ) or less, and the Hall mobility is 5(cm ² /V·s) or more, 40(cm ² /V·s) or less. The light-transmitting conductive film according to any one of claims 1 to 9, wherein the light-transmitting conductive layer is patterned.

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