KR20200098484A - Transparent conductive film - Google Patents

Abstract

The transparent conductive film is provided with a transparent resin base material, a hard coat layer, an optical adjustment layer, an adhesive layer, and a transparent conductive layer in this order. The adhesion layer is a resin layer containing nano silica particles, and the ratio of the number of silicon atoms to the number of carbon atoms is 0.50 or more on the surface of the adhesion layer on the transparent conductive layer side.

Description

Transparent conductive film

The present invention relates to a transparent conductive film, specifically, a transparent conductive film preferably used for an optical application.

Conventionally, a transparent conductive film in which a transparent conductive layer made of an indium tin composite oxide is formed in a desired electrode pattern is used for optical applications such as touch panels.

For example, in Patent Document 1, a transparent resin film, a hard coat layer, an intermediate layer, and a transparent conductive layer are sequentially provided, and the intermediate layer is made of metal oxide fine particles and an active energy ray-curable resin, and the refractive index is 1.65. A transparent conductive film of-1.90 is disclosed. In the transparent conductive film of Patent Literature 1 below, the coloration of transmitted light and the curling property of the film are suppressed, the patterned portion and the non-patterned portion in the transparent conductive layer cannot be identified, and the appearance as a display element is improved.

Japanese Patent Application Publication No. 2017-62609

However, in the transparent conductive film of the said patent document 1, the scratch resistance is low. That is, when the surface of the transparent conductive layer is rubbed, the transparent conductive layer is broken, and a part of the transparent conductive layer is peeled off and removed from the intermediate layer. As a result, the conductive performance is remarkably inferior.

Therefore, in order to suppress the peeling of the transparent conductive layer, it is considered to form an adhesive layer made of a resin between the intermediate layer and the transparent conductive layer (that is, on the lower surface of the transparent conductive layer).

However, when the adhesion layer is formed on the lower surface of the transparent conductive layer, when etching the transparent conductive layer with a desired pattern (eg, electrode pattern) with an etching solution or the like, the etching solution excessively etch the adhesion layer. More specifically, a portion of the adhesion layer that contacts the lower surface of the pattern portion of the transparent conductive layer is etched. As a result, the pattern portion is not supported by the adhesion layer, and a problem arises that a crack occurs in the pattern portion. That is, the patterning characteristics are inferior.

The present invention is to provide a transparent conductive film excellent in scratch resistance and patterning properties.

In the present invention [1], a transparent resin substrate, a hard coat layer, an optical adjustment layer, an adhesion layer, and a transparent conductive layer are provided in this order, and the adhesion layer is a resin layer containing nano silica particles. And a transparent conductive film in which the ratio of the number of silicon atoms to the number of carbon atoms is 0.50 or more on the surface of the adhesion layer on the side of the transparent conductive layer.

The present invention [2] includes the transparent conductive film according to [1], wherein the ratio of the number of silicon atoms to the number of carbon atoms is 1.00 or more.

The present invention [3] includes the transparent conductive film according to [1] or [2], in which the thickness of the adhesion layer is 10 nm or more and 100 nm or less.

The present invention [4] includes the transparent conductive film according to any one of [1] to [3], in which the transparent resin substrate is a cycloolefin polymer film.

According to the transparent conductive film of the present invention, a transparent resin substrate, a hard coat layer, an optical adjustment layer, an adhesion layer, and a transparent conductive layer are provided in this order, and the adhesion layer is a resin layer containing nano silica particles. to be. Therefore, the adhesion between the optical adjustment layer and the transparent conductive layer can be improved, and peeling and dropping of the transparent conductive layer can be suppressed. Therefore, it is excellent in scratch resistance.

Moreover, the ratio of the number of silicon atoms to the number of carbon atoms is 0.50 or more on the surface of the adhesion layer on the transparent conductive layer side. Therefore, when etching the transparent conductive layer, excessive etching to the adhesion layer can be suppressed, and cracks in the transparent conductive layer can be suppressed. Therefore, the patterning property of the transparent conductive layer is good.

1 shows a cross-sectional view of an embodiment of the transparent conductive film of the present invention.
Fig. 2 shows a cross-sectional view of an aspect in which the transparent conductive film shown in Fig. 1 is patterned.
3 shows a schematic diagram of a bending resistance test in Examples.

<one embodiment>

An embodiment of the transparent conductive film of the present invention will be described with reference to FIGS. 1 to 2.

In Fig. 1, the vertical direction of the paper is the vertical direction (thickness direction, the first direction), the upper side of the paper is the upper side (thickness direction one side, the first direction one side), the paper lower side, the lower side (thickness direction the other side) , The other side in the first direction). In addition, the left-right direction and the depth direction of the paper are plane directions orthogonal to the vertical direction. Specifically, it is based on the direction arrows in each drawing.

1. Transparent conductive film

The transparent conductive film 1 has a film shape (including a sheet shape) having a predetermined thickness, extends in a predetermined direction (surface 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 substrate for a touch panel provided in an image display device, and in other words, it is not an image display device. That is, the transparent conductive film 1 is a component for manufacturing an image display device and the like, and does not include an image display element such as an LCD module, and includes an anti-blocking layer 2, a transparent resin substrate 3, and a hard material. It includes a coating layer 4, an optical adjustment layer 5, an adhesion layer 6, and a transparent conductive layer 7, and distributes as a component alone, and is an industrially available device.

Specifically, as shown in FIG. 1, the transparent conductive film 1 includes a transparent resin substrate 3, an anti-blocking layer 2 disposed on the lower surface (the other side in the thickness direction) of the transparent resin substrate 3, and , A hard coat layer 4 disposed on the upper surface (one side in the thickness direction) of the transparent resin substrate 3, an optical adjusting layer 5 disposed on the upper surface of the hard coat layer 4, and an optical adjusting layer 5 ), and an adhesion layer 6 disposed on the upper surface of the adhesion layer 6, and a transparent conductive layer 7 disposed on the upper surface of the adhesion layer 6. More specifically, the transparent conductive film (1) is an anti-blocking layer (2), a transparent resin substrate (3), a hard coat layer (4), an optical adjustment layer (5), and an adhesion layer (6). And, the transparent conductive layer 7 is provided in this order. The transparent conductive film (1) is preferably an anti-blocking layer (2), a transparent resin substrate (3), a hard coat layer (4), an optical adjustment layer (5), an adhesion layer (6), and a transparent conductive layer ( 7).

2. Anti-blocking layer

The anti-blocking layer 2 is in close contact with the upper surface of one transparent conductive film 1 and the lower surface of the other transparent conductive film 1 disposed on the upper surface when a plurality of transparent conductive films 1 are laminated. It is a blocking-resistant layer for suppressing a blocking phenomenon in which a part of the transparent conductive film is peeled off when removing these. Moreover, it is also a scratch protective layer for preventing scratches from easily occurring on the upper surface of the transparent conductive film 1 (that is, the upper surface of the transparent conductive layer 7).

The anti-blocking layer 2 is the lowermost layer of the transparent conductive film 1 and has a film shape (including a sheet shape). The anti-blocking layer 2 is disposed on the entire lower surface of the transparent resin substrate 3 so as to contact the lower surface of the transparent resin substrate 3.

The anti-blocking layer 2 is formed of an anti-blocking composition. The anti-blocking layer 2 contains resin and particles. That is, the anti-blocking layer 2 is a resin layer containing particles.

Examples of the resin include a curable resin, a thermoplastic resin (eg, a polyolefin resin), and a curable resin is preferably used.

Examples of the curable resin include active energy ray-curable resins cured by irradiation with active energy rays (specifically, ultraviolet rays, electron beams, etc.), for example, thermosetting resins that are cured by heating. , Preferably, an active energy ray-curable resin is used.

The active energy ray-curable resin includes, for example, a polymer 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 acryloyl group), etc. are mentioned, for example.

As an active energy ray-curable resin, specifically, (meth)acrylic ultraviolet-curable resins, such as a urethane acrylate and an epoxy acrylate, are mentioned.

Moreover, as a curable resin other than an active energy ray-curable resin, a urethane resin, a melamine resin, an alkyd resin, a siloxane-based polymer, an organosilane condensate, etc. are mentioned, for example.

These resins can be used alone or in combination of two or more.

Examples of the particles include organic particles and inorganic particles. Examples of the organic particles include crosslinked acrylic particles such as crosslinked acrylic/styrene resin particles. Examples of the inorganic particles include silica particles, for example, metal oxide particles made of zirconium oxide, titanium oxide, zinc oxide, tin oxide, and the like, and carbonate particles such as calcium carbonate. Particles can be used alone or in combination of two or more.

Preferably, organic particles are used, and more preferably, crosslinked acrylic particles are used.

The average particle diameter (primary particle diameter) of the particles is, for example, 10 nm or more, preferably 100 nm or more, and, for example, 5 µm or less, preferably 3 µm or less.

The average particle diameter of the particles represents the average particle diameter (D ₅₀ ) of the particle size distribution on a volume basis, and for example, a solution in which particles are dispersed in water can be measured by a light diffraction/scattering method.

The content ratio of the particles is, for example, 0.1 parts by mass or more, preferably 0.2 parts by mass or more, and, for example, 10 parts by mass or less, preferably 5 parts by mass, based on 100 parts by mass of the resin. Below.

The anti-blocking composition may further contain known additives such as leveling agents, thixotropic agents, and antistatic agents.

The thickness of the anti-blocking layer 2 is, for example, 0.1 µm or more, preferably 0.5 µm or more, and, for example, 10 µm or less, preferably from the viewpoint of scratch resistance, anti-blocking property and peelability. Preferably, it is 3 μm or less. The thickness of the anti-blocking layer 2 can be calculated, for example, based on the wavelength of the interference spectrum observed using an instantaneous multi-photometric system (for example, "MCPD2000" manufactured by Otsuka Electronics Co., Ltd.).

3. Transparent resin substrate

The transparent resin substrate 3 is a transparent substrate for securing the mechanical strength of the transparent conductive film 1. That is, the transparent resin base material 3 is supporting the transparent conductive layer 7 together with the hard coat layer 4, the optical adjustment layer 5, and the adhesive layer 6.

The transparent resin substrate 3 has a film shape (including a sheet shape). The transparent resin substrate 3 is disposed on the entire upper surface of the anti-blocking layer 2 so as to contact the upper surface of the anti-blocking layer 2. More specifically, the transparent resin substrate 3 is disposed between the anti-blocking layer 2 and the hard coat layer 4 so as to contact the upper surface of the anti-blocking layer 2 and the lower surface of the hard coat layer 4 Has been.

The transparent resin substrate 3 is, for example, a polymer film having transparency. As the material of the transparent resin substrate 3, for example, polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate, for example (meth) such as polymethacrylate Olefin resins such as acrylic resins (acrylic resins and/or methacrylic resins), for example polyethylene, polypropylene, cycloolefin polymers (for example, norbornene-based, cyclopentadiene-based), such as polycarbonate Resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, polystyrene resin, and the like. The transparent resin substrate (3) can be used alone or in combination of two or more.

From the viewpoint of high transparency and low birefringence, the transparent resin substrate 3 is preferably a cycloolefin polymer film (COP film).

The tensile breaking strength of the transparent resin substrate 3 is, for example, 10 MPa or more, preferably 30 MPa or more, and, for example, 100 MPa or less, and preferably 85 MPa or less. When the tensile breaking strength is within the above range, when adopting the transparent conductive film 1 by a roll-to-roll method, the transparent resin substrate 3 can be conveyed satisfactorily, and cracks etc. in the transparent resin substrate 3 Can be suppressed.

Tensile breaking strength can be measured based on ISO 527.

The total light transmittance (JIS K 7375-2008) of the transparent resin substrate 3 is, for example, 80% or more, and preferably 85% or more.

The thickness of the transparent resin substrate 3 is, for example, 2 µm or more, preferably 20 µm or more, from the viewpoints of mechanical strength and spot characteristics when the transparent conductive film 1 is used as a film for a touch panel. And, for example, it is 300 µm or less, preferably 150 µm or less, and more preferably 50 µm or less. The thickness of the transparent resin substrate 3 can be measured using, for example, a micro-gauge type side thickness meter.

4. Hard coat layer

The hard coat layer 4 is a protective layer for suppressing the occurrence of scratches on the transparent resin substrate 3 when manufacturing the transparent conductive film 1. Moreover, when a plurality of transparent conductive films 1 are laminated, it is an abrasion resistant layer for suppressing the occurrence of scratches on the transparent conductive layer 7. It is also a layer for imparting bending resistance.

The hard coat layer 4 has a film shape (including a sheet shape). The hard coat layer 4 is disposed on the entire upper surface of the transparent resin substrate 3 so as to contact the upper surface of the transparent resin substrate 3. More specifically, the hard coat layer 4 is disposed between the transparent resin substrate 3 and the optical adjustment layer 5 so as to contact the upper surface of the transparent resin substrate 3 and the lower surface of the optical adjustment layer 5 Has been.

The hard coat layer 4 is formed from a hard coat composition. The hard coat composition contains resin. That is, the hard coat layer 4 is a resin layer.

Although it does not specifically limit as a resin, For example, resin exemplified by an anti-blocking composition is mentioned. Preferably, a curable resin, more preferably an active energy ray curable resin, and still more preferably a (meth)acrylic ultraviolet curable resin is used.

The hard coat composition may contain particles. Thereby, the hard coat layer 4 can be made into an anti-blocking layer having anti-blocking properties. Although it does not specifically limit as a particle, The particle|grains illustrated by an anti-blocking composition are mentioned.

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

From the viewpoint of scratch resistance, the thickness of the hard coat layer 4 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. to be. The thickness of the hard coat layer 4 can be calculated based on the wavelength of the interference spectrum observed using, for example, an instantaneous multi-photometric system.

5. Optical adjustment layer

The optical adjustment layer 5 suppresses the visibility of the wiring pattern in the transparent conductive layer 7, and in order to ensure the excellent transparency of the transparent conductive film 1, the optical properties of the transparent conductive film 1 (example For example, it is a layer to adjust the refractive index).

The optical adjustment layer 5 has a film shape (including a sheet shape), and is disposed on the entire upper surface of the hard coat layer 4 so as to contact the upper surface of the hard coat layer 4. More specifically, the optical adjustment layer 5 is disposed between the hard coat layer 4 and the adhesion layer 6 so as to contact the upper surface of the hard coat layer 4 and the lower surface of the adhesion layer 6 .

The optical adjustment layer 5 is formed of an optical adjustment composition. The optical adjustment composition contains a resin, and preferably contains a resin and a particle. That is, the optical adjustment layer 5 is preferably a resin layer containing particles.

Although it does not specifically limit as a resin, For example, the resin illustrated with an anti-blocking composition is mentioned. Preferably, a curable resin, more preferably an active energy ray curable resin, and still more preferably a (meth)acrylic ultraviolet curable resin is used.

The content ratio of the resin is, for example, 10 mass% or more, preferably 25 mass% or more, and, for example, 95 mass% or less, preferably 60 mass% or less with respect to the optical adjustment composition. to be.

As the particles, a preferable material can be selected according to the refractive index required by the optical adjustment layer, and for example, particles exemplified by the anti-blocking composition may be mentioned. From the viewpoint of the refractive index, preferably, inorganic particles, more preferably metal oxide particles, and still more preferably zirconium oxide particles (ZnO ₂ ) are exemplified.

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

The optical adjustment composition may further contain known additives such as leveling agents, thixotropic agents, and antistatic agents.

The refractive index of the optical adjustment layer 5 is, for example, 1.40 or more, preferably 1.55 or more, and, 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 5 is, for example, 5 nm or more, preferably 10 nm or more, and, for example, 100 nm or less, preferably 50 nm or less. The thickness of the optical adjustment layer 5 can be calculated based on the wavelength of the interference spectrum observed using, for example, an instantaneous multi-photometric system.

6. Adhesion layer

The adhesion layer 6 is the transparent conductive layer 7 and the transparent conductive layer 7 in order to suppress a part of the transparent conductive layer 7 from peeling and falling off from the transparent conductive film 1 when the transparent conductive layer 7 is scratched. It is a layer which adjusts (improves) the adhesiveness of the optical adjustment layer 5.

The adhesion layer 6 has a film shape (including a sheet shape), and is disposed on the entire upper surface of the optical adjustment layer 5 so as to contact the upper surface of the optical adjustment layer 5. More specifically, the adhesion layer 6 is disposed between the optical adjustment layer 5 and the transparent conductive layer 7 so as to contact the upper surface of the optical adjustment layer 5 and the lower surface of the transparent conductive layer 7 have.

The adhesion layer 6 is formed from the adhesion composition. The adhesion composition contains a resin and nano silica particles. That is, the adhesion layer 6 is a resin layer containing nano silica particles. Thereby, the adhesion layer 6 is reliably adhered to both of the optical adjustment layer 5 and the transparent conductive layer 7, and dropping of these can be suppressed.

Although it does not specifically limit as a resin, For example, the resin illustrated with an anti-blocking composition is mentioned. Preferably, a curable resin, more preferably an active energy ray curable resin, and still more preferably a (meth)acrylic ultraviolet curable resin is used.

The content ratio of the resin is, for example, 10 mass% or more, preferably 25 mass% or more, and, for example, 50 mass% or less, preferably 40 mass% or less with respect to the adhesion composition. . When the content ratio of the resin is within the above range, it is possible to suppress a decrease in the etching rate of the transparent conductive layer 7 due to excessive adhesion between the adhesion layer 6 and the transparent conductive layer 7.

The average particle diameter (primary particle diameter) of the nano silica particles is, for example, 1 nm or more, preferably 5 nm or more, and, for example, 100 nm or less, preferably 30 nm or less, more preferably Is 20 nm or less.

The average particle diameter of the nano silica particles represents the average particle diameter (D ₅₀ ) of the particle size distribution on a volume basis, and, for example, a solution in which the particles are dispersed in water can be measured by a light diffraction/scattering method.

The content ratio of the nano silica particles is, for example, 50 mass% or more, preferably 60 mass% or more, and, for example, 90 mass% or less, preferably 75 mass% with respect to the adhesion composition. Below. When the content ratio of the nano silica particles is more than the above lower limit, the ratio of the number of silicon atoms in the upper surface of the adhesion layer 6 can be set to a desired range, and patterning characteristics can be improved. Moreover, if the content ratio of the nano silica particles is less than or equal to the above upper limit, it is possible to suppress a decrease in the etching rate of the transparent conductive layer 7 due to excessive adhesion between the adhesion layer 6 and the transparent conductive layer 7.

The adhesion composition may further contain known additives such as a leveling agent, a thixotropic agent, and an antistatic agent.

In the upper surface of the adhesion layer 6 (the surface on the transparent conductive layer 7 side), the ratio of the number of silicon atoms to the number of carbon atoms (Si/C) is 0.50 or more, preferably 1.00 or more, and , For example, 2.00 or less. If the ratio is more than the above lower limit, erosion of the adhesion layer 6 (in particular, the adhesion layer 6 in contact with the lower surface of the transparent conductive layer 7) by the etching solution at the time of etching the transparent conductive layer 7 It can suppress, and cracks of the patterned transparent conductive layer 7 can be suppressed. As a result, the patterning property is excellent.

The ratio (Si/C) can be measured by X-ray photoelectron spectroscopy (electron spectroscopy for chemical analysis, ESCA). Specific conditions will be described later in Examples.

The thickness of the adhesion layer 6 is, for example, 10 nm or more, preferably 20 nm or more, and, for example, 100 nm or less, preferably 50 nm or less. The thickness of the adhesion layer 6 can be calculated, for example, based on the wavelength of the interference spectrum observed using an instantaneous multi-photometric system.

7. Transparent conductive layer

The transparent conductive layer 7 is a conductive layer for forming a transparent pattern portion 8 (to be described later) by crystallization as necessary and forming in a desired pattern in a post process.

The transparent conductive layer 7 is an uppermost layer of the transparent conductive film 1 and has a film shape (including a sheet shape). The transparent conductive layer 7 is disposed on the entire upper surface of the adhesion layer 6 so as to contact the upper surface of the adhesion layer 6.

As a material of the transparent conductive layer 7, for example, selected from the group consisting of In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, W And metal oxides containing at least one type of metal. The metal oxide may be further doped with a metal atom shown in the group as necessary.

Specific examples of the transparent conductive layer 7 include indium-containing oxides such as indium tin composite oxide (ITO), and antimony-containing oxides such as antimony tin composite oxide (ATO). In addition, preferably, an indium-containing oxide, more preferably, ITO is used.

When the transparent conductive layer 7 is an indium tin composite oxide layer such as an ITO layer, the tin oxide (SnO ₂ ) content is, for example, 0.5 mass with respect to the total amount of tin oxide and indium oxide (In ₂ O ₃ ). % Or more, preferably 3% by mass or more, and, for example, 15% by mass or less, preferably 13% by mass or less. When the content of tin oxide is more than the above lower limit, the durability of the transparent conductive layer 7 can be further improved. When the content of tin oxide is less than or equal to the above upper limit, crystal conversion of the transparent conductive layer 7 can be facilitated, and stability of transparency and surface resistance can be improved.

In the present specification, "ITO" may be a composite oxide containing at least indium (In) and tin (Sn), and may contain additional components other than these. As the additional component, for example, metal elements other than In and Sn may be mentioned, specifically, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, W , Fe, Pb, Ni, Nb, Cr, Ga, and the like.

The surface resistance of the transparent conductive layer 7 is, for example, 200 Ω/□ or more, preferably 250 Ω/□ or more, and, for example, 500 Ω/□ or less. Surface resistance can be measured by a four-terminal method.

The thickness of the transparent conductive layer 7 is, for example, 10 nm or more, preferably 15 nm or more, and, for example, 50 nm or less, preferably 30 nm or less. The thickness of the transparent conductive layer 7 can be measured using, for example, an instantaneous multi-photometric system.

The transparent conductive layer 7 may be either amorphous or crystalline.

Whether the transparent conductive layer is amorphous or crystalline, for example, when the transparent conductive layer is an ITO layer, is immersed in hydrochloric acid at 20°C (concentration 5% by mass) for 15 minutes, then washed with water and dried, for about 15 mm It can be determined by measuring the resistance between the terminals of. In this specification, after immersion, washing and drying in hydrochloric acid (20°C, concentration: 5% by mass), when the resistance between terminals between 15 mm exceeds 10 kΩ, the ITO layer becomes amorphous, and between 15 mm When the resistance between terminals of is 10 kΩ or less, the ITO layer becomes crystalline.

7. Manufacturing method of transparent conductive film

Next, the method of manufacturing the transparent conductive film 1 is demonstrated. In order to manufacture the transparent conductive film 1, for example, while forming the anti-blocking layer 2 on the lower surface (the other side in the thickness direction) of the transparent resin substrate 3, the upper surface (thickness) of the transparent resin substrate 3 In one direction), the hard coat layer 4 is formed. Next, on the upper surface of the hard coat layer 4, the optical adjustment layer 5, the adhesion layer 6, and the transparent conductive layer 7 are formed in this order. It will be described in detail below.

First, a known or commercially available transparent resin substrate 3 is prepared.

Then, if necessary, from the viewpoint of adhesion between the transparent resin substrate 3 and the anti-blocking layer 2 or the hard coat layer 4, on the lower surface or upper surface of the transparent resin substrate 3, for example, sputtering , Corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, etching treatment, such as oxidation, and a primer treatment can be performed. Further, the transparent resin substrate 3 can be vibration-removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like.

Next, the anti-blocking layer 2 is formed on the lower surface of the transparent resin substrate 3. For example, by wet-coating the anti-blocking composition on the lower surface of the transparent resin substrate 3, the anti-blocking layer 2 is formed on the lower surface of the transparent resin substrate 3.

Specifically, for example, a solution (varnish) obtained by diluting an anti-blocking composition with a solvent is prepared, and then, the anti-blocking composition solution is applied to the lower surface of the transparent resin substrate 3 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 the organic solvent include alcohol compounds such as methanol, ethanol, and isopropyl alcohol, such as ketone compounds such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, such as ethyl acetate and butyl acetate. And ether compounds such as propylene glycol monomethyl ether (PGME), and aromatic compounds such as toluene and xylene. These solvents can be used alone or in combination of two or more.

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

The application method can be appropriately selected according to the anti-blocking composition solution and the transparent resin substrate (3). Examples of the coating method include a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, and an extrusion coating method.

The drying temperature is, for example, 50°C or more, preferably 70°C or more, and for example, 200°C or less, preferably 100°C or less.

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

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

In addition, when the anti-blocking composition contains a thermosetting resin, the thermosetting resin can be thermosetted together with drying of the solvent by this drying step.

On the other hand, the hard coat layer 4 is formed on the upper surface of the transparent resin substrate 3. For example, the hard coat layer 4 is formed on the upper surface of the transparent resin base material 3 by wet-coating the hard coat composition on the upper surface of the transparent resin base material 3.

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

Conditions such as preparation, application, and drying of the hard coat composition can be the same as the conditions such as preparation, application, and drying exemplified in the anti-blocking composition.

Moreover, when the hard coat composition contains an active energy ray-curable resin, the active energy ray-curable resin is cured by irradiating an active energy ray after drying of the hard coat composition solution.

In addition, when the hard coat composition contains a thermosetting resin, the thermosetting resin can be thermosetted together with drying of the solvent by this drying step.

Next, the optical adjustment layer 5 is formed on the upper surface of the hard coat layer 4. For example, the optical adjustment layer 5 is formed on the upper surface of the hard coat layer 4 by wet-coating the optical adjustment composition on the upper surface of the hard coat layer 4.

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 4 and dried.

Conditions such as preparation, application, and drying of the optical adjustment composition can be the same as the conditions such as preparation, application, and drying exemplified in the anti-blocking composition.

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

In addition, when the optical adjustment composition contains a thermosetting resin, the thermosetting resin can be thermosetted together with drying of the solvent by this drying step.

Subsequently, an adhesion layer 6 is formed on the upper surface of the optical adjustment layer 5. For example, the adhesive layer 6 is formed on the upper surface of the optical adjustment layer 5 by wet-coating an adhesive composition on the upper surface of the optical adjustment layer 5.

Specifically, for example, a solution (varnish) obtained by diluting an adhesive composition with a solvent is prepared, and then the adhesive composition solution is applied to the upper surface of the optical adjustment layer 5 and dried.

Conditions such as preparation, application, and drying of the adhesion composition can be the same as the conditions such as preparation, application, and drying exemplified in the anti-blocking composition.

Moreover, when the adhesive composition contains an active energy ray-curable resin, after drying of an adhesive composition solution, an active energy ray-curable resin is hardened by irradiating an active energy ray.

In addition, when the adhesive composition contains a thermosetting resin, the thermosetting resin can be thermosetted together with drying of the solvent by this drying process.

Next, a transparent conductive layer 7 is formed on the upper surface of the adhesion layer 6. For example, the transparent conductive layer 7 is formed on the upper surface of the adhesion layer 6 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 used. By this method, a thin transparent conductive layer 7 can be formed.

In the case of employing the sputtering method, the above-described inorganic material constituting the transparent conductive layer 7 is exemplified as a target material, and ITO is preferably used. The tin oxide concentration of ITO is, for example, 0.5% by mass or more, preferably 3% by mass or more, and, for example, 15% by mass or less, preferably from the viewpoint of durability and crystallization of the ITO layer. Is 13 mass% or less.

As the sputtering gas, an inert gas, such as Ar, is mentioned, for example. Further, if necessary, a reactive gas such as oxygen gas can be used in combination. When a reactive gas is used together, the flow rate ratio of the reactive gas is not particularly limited, but is, for example, 0.1 flow% or more and 5 flow% or less with respect to the total flow rate ratio of the sputter gas and the reactive gas.

The sputtering method is carried out under vacuum. Specifically, the atmospheric pressure at the time of sputtering is, for example, 1 Pa or less, preferably 0.7 Pa or less from the viewpoints of suppression of a decrease in sputtering rate and discharge stability.

The power source used for 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 7 having a desired thickness, sputtering may be performed a plurality of times by appropriately setting a target material and sputtering conditions.

Moreover, in the said manufacturing method, while conveying the transparent resin base material 3 by a roll-to-roll system, to the transparent resin base material 3, the anti-blocking layer 2, the hard coat layer 4, the optical adjustment layer ( 5), the adhesion layer 6 and the transparent conductive layer 7 may be formed, and some or all of these layers may be formed by a batch method (single sheet method). From the viewpoint of productivity, preferably, each layer is formed on the transparent resin substrate 3 while conveying the transparent resin substrate 3 in a roll-to-roll system.

Thereby, as shown in FIG. 1, the anti-blocking layer (2), the transparent resin base material (3), the hard coat layer (4), the optical adjustment layer (5), the adhesion layer (6), and the transparent conductive layer (7) The transparent conductive film 1 provided in order is obtained. The transparent conductive film 1 shown in FIG. 1 is a non-patterned transparent conductive film which has not been subjected to patterning treatment.

The thickness of the obtained transparent conductive film (1) is, for example, 2 µm or more, preferably 20 µm or more, and, for example, 300 µm or less, preferably 100 µm or less, more preferably , 50 μm or less.

Subsequently, if necessary, the transparent conductive layer 7 is patterned on the non-patterned transparent conductive film by known etching.

The pattern of the transparent conductive layer 7 is appropriately determined depending on the application to which the transparent conductive film 1 is applied, but, for example, an electrode pattern such as a stripe or a wiring pattern is mentioned.

Etching, for example, so as to correspond to the pattern portion 8 and the non-pattern portion 9, a covering portion (masking tape, etc.) is disposed on the transparent conductive layer 7, and the transparent conductive layer exposed from the covering portion ( 7) The (non-pattern part 9) is etched using an etching solution. 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. After that, the covering portion is removed from the upper surface of the transparent conductive layer 7 by, for example, peeling.

Thereby, as shown in FIG. 2, the patterned transparent conductive film 1a in which the transparent conductive layer 7 was patterned is mentioned.

Further, if necessary, before or after etching, a crystal conversion treatment is performed on the transparent conductive layer 7 of the transparent conductive film 1.

Specifically, heat treatment is performed on the transparent conductive film 1 in the atmosphere.

The heat treatment can be performed using, for example, an infrared heater or an oven.

The heating temperature is, for example, 100°C or more, preferably 120°C or more, and, for example, 200°C or less, preferably 160°C or less. When the heating temperature is within the above range, it is possible to ensure crystal conversion while suppressing thermal damage to the transparent resin substrate 3 and impurities generated from the transparent resin substrate 3.

The heating time is appropriately determined depending on the heating temperature, but is, for example, 10 minutes or more, preferably 30 minutes or more, and, for example, 5 hours or less, preferably 3 hours or less.

Thereby, the transparent conductive film 1 in which the transparent conductive layer 7 is crystallized is obtained.

The transparent conductive film 1 is provided in an optical device, for example. As an optical device, an image display device etc. are mentioned, for example. When the transparent conductive film 1 is provided in an image display device (specifically, an image display device having an image display element such as an LCD module), the transparent conductive film 1 is, for example, a substrate for a touch panel. Is used as As the form of the touch panel, various methods such as an optical method, an ultrasonic method, a capacitive method, and a resistive film method may be mentioned, and in particular, it is preferably used for a capacitive touch panel.

And this transparent conductive film (1) is a transparent resin substrate (3), a hard coat layer (4), an optical adjustment layer (5), an adhesion layer (6), and a transparent conductive layer (7). It is provided in order. The adhesion layer 6 is a resin layer containing nano silica particles. Therefore, the adhesion between the optical adjustment layer 5 and the transparent conductive layer 7 can be improved. Therefore, even if the upper surface of the transparent conductive film 1 is rubbed and the transparent conductive layer 7 is broken, the transparent conductive layer 7 is formed on the surface of the transparent conductive film 1 due to the presence of the adhesion layer 6. Can be maintained. That is, peeling and falling off of the transparent conductive layer 7 can be suppressed. As a result, it is possible to suppress a remarkable decrease in the conductive performance due to a defect in the transparent conductive layer 7 (specifically, an excessive increase in the surface resistance value). Therefore, it is excellent in scratch resistance.

Moreover, in the upper surface of the adhesion layer 6, the ratio (Si/C) of the number of silicon atoms to the number of carbon atoms is 0.50 or more. Therefore, since silicon atoms (nano silica particles) are sufficiently present on the upper surface of the adhesion layer 6, when etching the transparent conductive layer 7 with the etching solution, the etching solution is used for etching the adhesion layer 6 (in particular, Etching of the adhesive layer portion that contacts the lower surface of the transparent conductive layer 7) can be suppressed. As a result, it is possible to suppress the occurrence of cracks in the transparent conductive layer 7 resulting from a defect in the adhesion layer 6 supporting the transparent conductive layer 7. Therefore, the patterning property of the transparent conductive layer 7 is good.

Moreover, this transparent electroconductive film 1 is equipped with the transparent resin base material 3 and the hard coat layer 4 arrange|positioned on the upper surface. For this reason, the transparent resin substrate 3 is reliably protected by the hard coat layer 4. Therefore, when the transparent conductive layer 7 is formed on the upper side of the transparent resin substrate 3 (especially a soft substrate COP film) by a dry method (especially a sputtering method), scratches on the transparent resin substrate 3 Can be suppressed. Therefore, the appearance of the transparent conductive film 1 can be improved. Further, since the hard coat layer 4 is provided, breakage and breakage at the time of bending can be suppressed, and the bending resistance is excellent.

Moreover, in this transparent conductive film 1, Preferably, the transparent resin base material 3 is a COP film. Since the COP film has a lower birefringence than other resin films such as PET films and has a phase difference of substantially zero, it is useful in terms of preventing the polarization of the polarizing plate and the film for a touch panel from being resolved. However, since the COP film is soft, defects of the transparent conductive layer 7 due to scratches are more likely to occur than other resin films such as PET films. And, according to this transparent conductive film (1), especially in the case where such a transparent resin base material (3) is a COP film, it solves the said subject by abrasion and patterning, and furthermore, transparent resin base material (3) It is also possible to solve the problem of appearance defects due to scratches of.

<modification example>

In one embodiment, the transparent conductive film 1 is provided with the anti-blocking layer 2 disposed on the lower surface of the transparent resin substrate 3, but, for example, not shown, instead of the anti-blocking layer 2 In addition, other functional layers may be provided. As a functional layer, the hard coat layer 4 etc. mentioned above are mentioned, for example.

In addition, in one embodiment, the transparent conductive film 1 is provided with the anti-blocking layer 2 disposed on the lower surface of the transparent resin substrate 3, but for example, although not shown, the anti-blocking layer 2 ) Do not have to be provided. That is, the transparent conductive film 1 may be provided with only the transparent resin substrate 3, the hard coat layer 4, the optical adjustment layer 5, the adhesion layer 6, and the transparent conductive layer 7.

Example

Examples and comparative examples are shown below, and the present invention will be described in more detail. In addition, the present invention is not limited to Examples and Comparative Examples at all. In addition, specific values such as the mixing ratio (containing ratio), physical properties, and parameters used in the following description are described in the above ``Specific Contents for Carrying out the Invention'', and the corresponding mixing ratio (containing Ratio), physical properties, parameters, etc., the upper limit (a value defined as ``below'' or ``less than'') or a lower limit (a value defined as ``above'' or ``excess'') can be substituted.

Example 1

As a transparent resin base material, a norbornene resin film (COP film, thickness 40 micrometers, Nippon Xeon company make, "Zeonoa film", tensile breaking strength 76 MPa) was prepared.

100 parts by mass of a resin composition solution having ultraviolet curing properties (a urethane acrylate resin composition, a mixture of 80% by mass of “Unidic ELS-888” and 20% by mass of “Unidic RS-605” manufactured by DIC), and crosslinking 0.4 parts by mass of acrylic particles (average particle diameter of 1.8 µm, manufactured by Soken Chemical Corporation, "MX-180TA") were mixed to prepare an anti-blocking composition solution. The anti-blocking composition solution was applied to the lower surface of the transparent resin substrate, and dried at 80°C for 1 minute. Thereafter, ultraviolet rays were irradiated with an ozone type high pressure mercury lamp to cure the anti-blocking composition. As a result, an anti-blocking layer having a thickness of 1.0 µm was formed.

On the other hand, on the upper surface of the transparent resin substrate, a hard coat composition solution (acrylic resin composition, manufactured by Ica Industrial Co., Ltd., "Z-850-6L") was applied and dried at 80°C for 1 minute. After that, ultraviolet rays were irradiated with an ozone type high pressure mercury lamp to cure the hard coat composition. As a result, a hard coat layer having a thickness of 1.0 µm was formed.

Next, on the upper surface of the hard coat layer, a solution of an optical adjustment composition having ultraviolet curing properties (containing zirconia particles, manufactured by Arakawa Chemical Industries, "Opstar KZ6955") was applied to the upper surface of the hard coat layer, and dried at 60°C for 1 minute. Made it. Then, ultraviolet rays were irradiated with an ozone type high pressure mercury lamp, and the optical adjustment composition was cured. Thereby, an optical adjustment layer having a thickness of 25 nm and a refractive index of 1.68 was formed.

Subsequently, as an adhesive composition having ultraviolet curing properties, a composition solution containing 60 parts by mass of nano silica particles (average primary particle diameter of 10 nm), 40 parts by mass of acrylic resin, and a solvent (PGME) ("Opstar" manufactured by Arakawa Chemical Industries, Ltd. Z7549") was prepared. The adhesive composition solution was applied to the upper surface of the optical adjustment layer, and dried at 60°C for 1 minute. Thereafter, ultraviolet rays were irradiated with an ozone type high pressure mercury lamp to cure the adhesive composition. Thereby, an adhesion layer having a thickness of 40 nm was formed.

Next, on the upper surface of the adhesion layer, an amorphous ITO layer (transparent conductive layer) having a thickness of 26 nm was formed by DC sputtering. Specifically, an ITO target composed of a sintered body of 80 mass% indium oxide and 20 mass% tin oxide was sputtered in a vacuum atmosphere at an atmospheric pressure of 0.4 Pa into which 98% of argon gas and 2% of oxygen gas were introduced. In addition, the surface resistance value of the transparent conductive layer was 340 Ω/□.

Thereby, a transparent conductive film composed of an anti-blocking layer/transparent resin substrate/hard coat layer/optical adjustment layer/adhesion layer/transparent conductive layer was produced.

Example 2

Except having changed the composition of the adhesive composition to the composition shown in Table 1, it carried out similarly to Example 1, and produced the transparent conductive film.

Comparative Examples 1 to 3

Except having changed the composition of the adhesive composition to the composition shown in Table 1, it carried out similarly to Example 1, and produced the transparent conductive film.

Comparative Example 4

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

Comparative Example 5

Except having not formed the hard coat layer, it carried out similarly to Example 1, and produced the transparent conductive film.

(Measurement of the element ratio of the adhesion layer)

With respect to the surface of the adhesion layer of the intermediate film (anti-blocking layer/transparent resin substrate/hard coat layer/optical adjustment layer/adhesion layer) at the time of forming the adhesion layer, surface element analysis was performed by X-ray photoelectron spectroscopy (ESCA). Implemented.

Specifically, after performing cleaning by Ar ion etching (about 1 nm in terms of SiO ₂ ) on the adhesion layer of the intermediate film, qualitative analysis was performed by measuring by wide scan. Next, Nero scan measurement was performed for C, N, O, and Si elements, and the element ratio (atomic%) was calculated. Measurement conditions were carried out as follows.

Device: manufactured by ULVAC-PHI, 「Quantum 2000」

X-ray source: Monochrome Al Kα

X-ray setting: 100 ㎛φ (15 ㎸, 25 W)

Photoelectron extraction angle: 45 degrees

Neutralization condition: Combination of neutralization gun and Ar ion gun (neutralization mode)

Acceleration voltage of Ar ion gun: 1 kV

Raster size of Ar ion gun: 2 ㎜ × 2 ㎜

Ar ion gun etching rate: about 2 nm/min in terms of SiO ₂

Table 1 shows the content ratio (atomic%) of the C element and the Si element, and their ratio.

(Scratch resistance)

An industrial wiper (manufactured by CONTEC, ``Anticon, Gold Sorb'') was applied to the surface of the transparent conductive layer of the transparent conductive film of each Example and Comparative Example to a load of 400 g in the range of φ 11 mm, and the length was 10 cm. Was slid 20 times. Thereafter, in order to measure the direction orthogonal to the sliding direction, a four-probe type probe was placed on the transparent conductive layer, and the surface resistance R ₂₀ of the transparent conductive film after sliding was measured. In addition, and the surface resistance value of that place before sliding to R _0.

The case where the rate of change R ₂₀ /R ₀ of the surface resistance value was less than 1.20 was evaluated as ?, and the case was 1.20 or more was evaluated as x. Table 1 shows the results.

(Patterning characteristics)

On the surface of the transparent conductive layer of the transparent conductive film of each Example and each comparative example, a commercially available adhesive tape (1 cm in width) at intervals of 1 cm was adhered in a stripe shape, and 10 wt% hydrochloric acid at 50°C was Using, the transparent conductive layer (ITO layer) was etched. Then, the adhesive tape was peeled from the transparent conductive layer, and the surface of the exposed transparent conductive layer (pattern part) was observed under a microscope (magnification: 20 times).

The case where the occurrence of cracks was not confirmed on the surface of the transparent conductive layer was evaluated as ◯, and the case where the occurrence of cracks was confirmed was evaluated as ×. Table 1 shows the results.

(Exterior)

The transparent conductive films of each Example and each Comparative Example were observed visually.

In the transparent electroconductive film, the case where a flaw at the time of manufacture was not confirmed was evaluated as ○, and the case where a flaw was confirmed was evaluated as x. Table 1 shows the results.

(Flexibility resistance)

The transparent conductive film was cut into a width of 50 mm x a length of 100 mm, folded in two so that the anti-blocking layer was inside, and both ends in the longitudinal direction of the film were bonded together with an adhesive tape to obtain a sample 10.

On the upper surface of the sample 10 (50 mm in width x 50 mm in length), the disc-shaped weight 11 (diameter 50 mm, weight 500 g) was allowed to stand for 10 seconds, and then the bent portion of the sample 10 (12) was observed (see Fig. 3).

The case where no fracture occurred in the bent portion was evaluated as ?, and the case where the fracture occurred in the bent portion and the film was broken was evaluated as x. Table 1 shows the results.

In addition, although the said invention was provided as an exemplary embodiment of this invention, this is only a mere illustration and should not be interpreted limitedly. Modification examples of the present invention that are evident by a person in the art are included in the later claims.

Industrial availability

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

1: transparent conductive film
3: transparent resin substrate
4: hard coat layer
5: optical adjustment layer
6: adhesion layer
7: transparent conductive layer

Claims (4)

A transparent resin substrate, a hard coat layer, an optical adjustment layer, an adhesion layer, and a transparent conductive layer are provided in this order,
The adhesion layer is a resin layer containing nano silica particles,
A transparent conductive film, characterized in that the ratio of the number of silicon atoms to the number of carbon atoms is 0.50 or more on the surface of the adhesion layer on the side of the transparent conductive layer. The method of claim 1,
The transparent conductive film, wherein the ratio of the number of silicon atoms to the number of carbon atoms is 1.00 or more. The method according to claim 1 or 2,
The transparent conductive film, characterized in that the thickness of the adhesion layer is 10 nm or more and 100 nm or less. The method according to claim 1 or 2,
The transparent conductive film, wherein the transparent resin substrate is a cycloolefin polymer film.

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