JP7323293B2 - Conductive film and touch panel - Google Patents

Description

TECHNICAL FIELD The present invention relates to a conductive film and a touch panel provided with the same.

2. Description of the Related Art Conventionally, it has been known that an image display device is provided with a transparent conductive film, as a film for a touch panel, in which a transparent conductive layer such as an indium tin composite oxide (ITO) layer is arranged on a transparent substrate. In recent years, in such a transparent conductive film, a conductive film in which a copper layer is further disposed on the upper surface of the ITO layer has been proposed in order to form a routed wiring on the outer edge of the touch input area to narrow the frame. (See Patent Document 1, for example).

JP 2013-139129 A

In the conductive film of Patent Document 1, an oxide film layer is further formed on the upper surface of the copper layer in order to suppress blocking between the laminated conductive films when wound into a roll.

However, in the conductive film of Patent Document 1, discoloration of the outermost surface (oxide film layer) of the conductive film occurs when stored for a long period of time, resulting in corrosion of the copper layer. That is, it is inferior in long-term storage stability.

Accordingly, an object of the present invention is to provide a conductive film and a touch panel having good long-term storage stability.

The present invention [1] comprises a transparent substrate, a transparent conductive layer, a copper layer, and an oxide film layer in this order in one thickness direction, and the oxide film layer has a water contact angle of 70° or more on one side in the thickness direction. , including conductive films.

The present invention [2] includes the conductive film according to [1], wherein the ratio of copper hydroxide on one surface in the thickness direction of the oxide film layer is 20 area % or less.

The present invention [3] includes the conductive film according to [1] or [2], wherein the ratio of copper on one surface in the thickness direction of the oxide film layer is 25 area% or less.

The present invention [4] is the conductive film according to any one of [1] to [3], wherein the ratio of copper (I) oxide on one side in the thickness direction of the oxide film layer is 40 area% or more. including.

The present invention [5] includes the conductive film according to any one of [1] to [4], wherein the oxide film layer has a thickness of 5 nm or more.

The present invention [6] includes a touch panel comprising the conductive film according to any one of [1] to [5].

According to the conductive film and touch panel of the present invention, the transparent substrate, the transparent conductive layer, the copper layer, and the oxide film layer are provided in order in one direction in the thickness direction, and the water contact angle on one side in the thickness direction of the oxide film layer is 70. ° or more. Therefore, discoloration of the oxide film layer can be suppressed for a long period of time, and the long-term storage stability is excellent.

FIG. 1 shows a side cross-sectional view of one embodiment of the conductive film of the present invention. FIG. 2 shows a side cross-sectional view of a patterned conductive film formed from the conductive film shown in FIG.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the vertical direction on the page is the vertical direction (thickness direction), the upper side on the page is the upper side (one side in the thickness direction), and the lower side on the page is the lower side (the other side in the thickness direction). Moreover, the left-right direction and the depth direction on the paper surface are plane directions orthogonal to the up-down direction. Specifically, it conforms to the directional arrows in each figure.

<First embodiment>
1. Conductive Film The conductive film 1, which is the first embodiment of the conductive film of the present invention, has a film shape (including a sheet shape) extending in the plane direction and having a predetermined thickness, for example, as shown in FIG. have. The film shape is defined as a thin plate shape having a flat upper surface (one surface in the thickness direction) and a flat lower surface (the other surface in the thickness direction) (the same applies hereinafter).

The conductive film 1 is, for example, one component such as a base material for a touch panel provided in an image display device, that is, it is not an image display device. That is, the conductive film 1 is a component for producing an image display device or the like, does not include an image display element such as an LCD module, is distributed as a component alone, and is a device that can be used industrially.

Specifically, as shown in FIG. 1, the conductive film 1 includes a transparent substrate 3, a first hard coat layer 2 arranged on the lower surface of the transparent substrate 3, and an upper surface of the transparent substrate 3. a second hard coat layer 4, a transparent conductive layer 5 arranged on the upper surface of the second hard coat layer 4, a copper layer 6 arranged on the upper surface of the transparent conductive layer 5, and arranged on the upper surface of the copper layer 6 and an oxide film layer 7 to be applied. That is, the conductive film 1 is a transparent conductive film with a copper layer, comprising a first hard coat layer 2, a transparent base material 3, a second hard coat layer 4, a transparent conductive layer 5, a copper layer 6 and an oxide film layer. 7 are provided in order from the bottom to the top. Preferably, conductive film 1 comprises first hard coat layer 2 , transparent substrate 3 , second hard coat layer 4 , transparent conductive layer 5 , copper layer 6 and oxide layer 7 . Each layer will be described in detail below.

2. First Hard Coat Layer The first hard coat layer 2 is a scratch protection layer for making the conductive film 1 less likely to be scratched. In addition, the first hard coat layer 2 is provided for imparting blocking resistance to the surfaces of a plurality of conductive films 1 in contact with each other, for example, when the conductive film 1 is wound in a roll and laminated in the radial direction. It is also an anti-blocking layer.

The first hard coat layer 2 has a film shape and is arranged as the bottom layer of the conductive film 1 .

The first hard coat layer 2 is a cured resin layer made of a hard coat composition.

The hard coat composition of the first hard coat layer 2 contains a resin, preferably a resin and particles.

Examples of resins include curable resins and thermoplastic resins (eg, polyolefin resins), 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.), and thermosetting resins that are cured by heating. Active energy ray-curable resins are preferred.

Active energy ray-curable resins include, for example, polymers having functional groups having polymerizable carbon-carbon double bonds in the molecule. Examples of such functional groups include vinyl groups, (meth)acryloyl groups (methacryloyl groups and/or acryloyl groups), and the like.

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

Examples of curable resins other than active energy ray-curable resins include thermosetting resins such as urethane resins, melamine resins, alkyd resins, siloxane-based polymers, and organic silane condensates.

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

Examples of particles include inorganic particles and organic particles. Examples of inorganic particles include silica particles, metal oxide particles such as zirconium oxide, titanium oxide, zinc oxide and tin oxide, and carbonate particles such as calcium carbonate. Examples of organic particles include crosslinked acrylic resin particles. The particles can be used singly or in combination of two or more.

From the viewpoint of transparency, the particles are preferably organic particles, more preferably crosslinked acrylic resin particles.

The content of the particles is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, and for example, 5 parts by mass or less, preferably 1 part by mass, with respect to 100 parts by mass of the resin. It is below.

From the viewpoint of scratch resistance and blocking resistance, the thickness of the first hard coat layer 2 is, for example, 0.1 μm or more, preferably 0.5 μm or more, and is, for example, 10 μm or less, preferably 5 μm or less. is. The thickness of each hard coat layer can be measured, for example, with a spectroscopic ellipsometer.

3. Transparent Base Material The transparent base material 3 is a base material for ensuring the mechanical strength of the conductive film 1 . The transparent base material 3 supports the transparent conductive layer 5 , the copper layer 6 and the oxide film layer 7 together with the first hard coat layer 2 and the second hard coat layer 4 .

The transparent base material 3 has a film shape and is arranged on the entire upper surface of the first hard coat layer 2 so as to be in contact with the upper surface of the first hard coat layer 2 . Specifically, the transparent substrate 3 is placed between the first hard coat layer 2 and the second hard coat layer 4 so as to be in contact with the top surface of the first hard coat layer 2 and the bottom surface of the second hard coat layer 4 . is located in

The transparent substrate 3 is, for example, a polymer film having transparency. Materials for the polymer film include, for example, polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate; , polyethylene, polypropylene, and cycloolefin polymer (COP), such as polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, and polystyrene resin. Polymer films can be used singly or in combination of two or more.

From the viewpoint of transparency, heat resistance, mechanical strength, etc., polyester resins and olefin resins are preferred, and PET and COP are more preferred.

The thickness of the transparent base material 3 is, for example, 2 μm or more, preferably 20 μm or more, from the viewpoint of mechanical strength, scratch resistance, and spotting characteristics when the conductive film 1 is used as a touch panel film. For example, it is 300 μm or less, preferably 150 μm or less.

The thickness of the transparent substrate 3 can be measured using, for example, a film thickness gauge (digital dial gauge).

In addition, an easy-adhesion layer, an adhesive layer, a separator, etc. may be provided on the upper surface and/or the lower surface of the transparent base material 3, if necessary.

4. Second Hard Coat Layer The second hard coat layer 4 is a scratch protection layer for making the conductive film 1 less likely to be scratched. The second hard coat layer 4 is also an antiblocking layer.

The second hard coat layer 4 has a film shape and is arranged on the entire upper surface of the transparent base material 3 so as to be in contact with the upper surface of the transparent base material 3 . Specifically, the second hard coat layer 4 is arranged between the transparent substrate 3 and the transparent conductive layer 5 so as to be in contact with the upper surface of the transparent substrate 3 and the lower surface of the transparent conductive layer 5. .

The second hard coat layer 4 is the same layer as the first hard coat layer 2 , and includes, for example, the same layers as those described above for the first hard coat layer 2 .

Preferably, the hard coat composition of the second hard coat layer 4 contains a resin, preferably consisting of resin and particles.

Examples of the resin and particles include those similar to the resins of the hard coat composition described above.

The thickness of the second 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, from the viewpoint of scratch resistance and visibility suppression of the patterned transparent conductive layer 5A. , preferably 5 μm or less.

5. Transparent Conductive Layer The transparent conductive layer 5 is a conductive layer that is formed into a desired pattern (patterned transparent conductive layer 5A described later) in a patterning process described later, and becomes, for example, an electrode pattern or a wiring pattern in a touch input area of a touch panel. .

The transparent conductive layer 5 has a film shape and is arranged on the entire upper surface of the second hard coat layer 4 so as to be in contact with the upper surface of the second hard coat layer 4 . More specifically, the transparent conductive layer 5 is arranged between the second hard coat layer 4 and the copper layer 6 so as to be in contact with the upper surface of the first hard coat layer 2 and the lower surface of the copper layer 6. there is

At least one selected from the group consisting of In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, and W as the material of the transparent conductive layer 5, for example. metal oxides containing metals of The metal oxide may be further doped with a metal atom shown in the above group, if necessary.

Specific examples of the transparent conductive layer 5 include indium-containing oxides such as indium-tin composite oxide (ITO) and antimony-containing oxides such as antimony-tin composite oxide (ATO). Indium-containing oxides are preferred, and ITO is more preferred.

When ITO is used as the material of the transparent conductive layer 5, the tin oxide (SnO ₂ ) content is preferably, for example, 0.5% by mass or more with respect to the total amount of tin oxide and indium oxide (In ₂ O ₃ ). is 3% by mass or more, and is, for example, 15% by mass or less, preferably 13% by mass or less. If the content of tin oxide is at least the above lower limit, the durability of the ITO layer can be further improved. When the content of tin oxide is equal to or less than the above upper limit, the crystal conversion of the ITO layer can be facilitated, and the stability of transparency and specific resistance can be improved.

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

The transparent conductive layer 5 may be either crystalline or amorphous.

The thickness of the transparent conductive layer 5 is, for example, 10 nm or more, preferably 20 nm or more, and for example, 50 nm or less, preferably 30 nm or less.

The thickness of the transparent conductive layer 5 can be measured, for example, by observing the cross section of the conductive film 1 using a transmission electron microscope.

6. Copper Layer The copper layer 6 is formed into a desired pattern (patterned copper layer 6A, which will be described later) in a patterning process, which will be described later. For example, it is a conductive layer that becomes a routing wiring.

The copper layer 6 has a film shape and is arranged on the entire upper surface of the transparent conductive layer 5 so as to be in contact with the upper surface of the transparent conductive layer 5 . More specifically, the copper layer 6 is arranged between the transparent conductive layer 5 and the oxide film layer 7 so as to be in contact with the upper surface of the transparent conductive layer 5 and the lower surface of the oxide film layer 7 .

Examples of materials for the copper layer 6 include copper and copper alloys. Metals constituting the copper alloy are not limited, and examples thereof include silver, tin, chromium, and zirconium. Copper is preferred from the viewpoint of conductivity and the like.

The thickness of the copper layer 6 is, for example, 100 nm or more, preferably 150 nm or more, and for example, 400 nm or less, preferably 300 nm or less. If the thickness of the copper layer 6 is equal to or more than the above lower limit, the conductivity of the copper layer 6 is excellent. Therefore, it is possible to form a narrower and longer wiring pattern (copper wiring in the frame portion) in response to the upsizing of the touch panel. If the thickness of the copper layer 6 is equal to or less than the above upper limit, the thickness of the frame portion can be reduced.

The thickness of the copper layer 6 can be measured using, for example, a fluorescent X-ray analyzer.

7. Oxide Film Layer The oxide film layer 7 is a protective layer for suppressing a decrease in conductivity due to natural oxidation of the copper layer 6 . Also, it is formed in a desired pattern (patterned oxide film layer 7A to be described later) together with the copper layer 6, and is a layer that becomes, for example, a wiring pattern (eg, routing wiring) in the outer edge portion outside the touch input area.

The oxide film layer 7 has a film shape and is the uppermost layer of the conductive film 1 . More specifically, the oxide film layer 7 is arranged over the entire upper surface of the copper layer 6 so as to be in contact with the upper surface of the copper layer 6 .

The material of the oxide film layer 7 is mainly composed of an oxide of copper or a copper alloy. Metals constituting the copper alloy are not limited, and examples thereof include silver, tin, chromium, and zirconium. From the viewpoint of electrical conductivity, copper oxide is preferred.

Specifically, the abundance ratio of copper hydroxide on the upper surface of the oxide film layer 7 is, for example, 20 area % or less, preferably 19 area % or less, and for example, 5 area % or more, preferably 10 area % or more. is.

The abundance ratio of copper (metal) is, for example, 25 area % or less, preferably 20 area % or less, and is, for example, 5 area % or more, preferably 10 area % or more.

The abundance ratio of copper (I) oxide is, for example, 40 area % or more, preferably 55 area % or more, and is, for example, 90 area % or less, preferably 85 area % or less.

If the abundance ratio is within the above range, the water contact angle of the upper surface of the oxide film layer 7, which will be described later, can be 70° or more.

Each abundance ratio can be measured using an X-ray photoelectron spectrometer.

The water contact angle of the upper surface of the oxide film layer 7 is 70° or more, preferably 75° or more, more preferably 80° or more, and is, for example, 150° or less, preferably 120° or less, more preferably. is less than or equal to 90°. If the water contact angle is equal to or greater than the lower limit, discoloration of the oxide film layer 7 after long-term storage can be suppressed.

The water contact angle is obtained by measuring the angle between the water droplet and the oxide film layer 7 five seconds after dropping a water droplet of 1.0 μL on the upper surface of the oxide film layer 7 using a contact angle meter.

The thickness of the oxide film layer 7 is, for example, 3 nm or more, preferably 5 nm or more, and is, for example, 30 nm or less, preferably 20 nm or less. If the thickness of the oxide film layer 7 is within the above range, the upper portion of the conductive film 1 (the oxide film layer 7 and the copper layer 6) can be further inhibited from changing its surface resistance over time (natural oxidation). It is possible to further reduce variations in surface resistance.

The ratio of the thickness of the oxide film layer 7 to the thickness of the copper layer 6 (oxide film layer 7/copper layer 6) is, for example, 1/100 or more, preferably 5/100 or more, and is, for example, 50/100. Below, it is preferably 30/100 or less. When the above ratio is within the range, the long-term storage stability can be further improved.

For the thickness of the oxide film layer 7, for example, the total thickness A1 of the oxide film layer 7 and the copper layer 6 and the thickness A2 of only the copper layer 6 are measured using a fluorescent X-ray analyzer, and the difference between them is determined. can be measured by calculating The thickness A2 of only the copper layer 6 can be measured, for example, by treating the conductive film 1 with 1 wt % hydrochloric acid to remove (dissolve) the oxide film layer 7 on the outermost surface. can.

8. Method for producing conductive film In order to produce the conductive film 1, for example, in a roll-to-roll process, the first hard coat layer 2 is provided on the other surface of the transparent substrate 3, while one surface of the transparent substrate 3 is Then, a second hard coat layer 4, a transparent conductive layer 5, a copper layer 6 and an oxide film layer 7 are provided in this order. Specifically, the first hard coat layer 2 or the second hard coat layer 2 is applied to the upper surface or the lower surface of the transparent substrate 3 while the transparent substrate 3 elongated in the longitudinal direction is delivered from the delivery roll and transported downstream in the transport direction. A coat layer 4 is provided, then a transparent conductive layer 5 is provided on the upper surface of the second hard coat layer 4, then a copper layer 6 is provided on the upper surface of the transparent conductive layer 5, and then an oxide film layer is provided on the upper surface of the copper layer 6. 7 is provided, and the conductive film 1 is wound up with a winding roll. Details will be described below.

First, a long transparent base material 3 wound around a delivery roll is prepared, and the transparent base material 3 is conveyed so as to be wound around the take-up roll.

After that, from the viewpoint of adhesion between the transparent substrate 3 and the hard coat layer, the surface of the transparent substrate 3 may be subjected to, for example, sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, or oxidation, if necessary. Etching treatment and undercoating treatment can be performed. Further, the transparent substrate 3 can be dust-removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like.

Next, the first hard coat layer 2 is provided on the bottom surface of the transparent substrate 3 . For example, the first hard coat layer 2 is formed on the lower surface of the transparent substrate 3 by wet coating the hard coat composition on the lower surface of the transparent substrate 3 .

On the other hand, a second hard coat layer 4 is provided on the top surface of the transparent substrate 3 . For example, the second hard coat layer 4 is formed on the upper surface of the transparent substrate 3 by wet coating the hard coat composition on the upper surface of the transparent substrate 3 .

Specifically, for example, a hard coat composition coating liquid is prepared by diluting the hard coat composition with a solvent, and then the coating liquid is applied to the lower and upper surfaces of the transparent substrate 3 and dried.

Examples of the solvent include organic solvents and aqueous solvents (specifically, water), and organic solvents are preferred. Examples of organic solvents include alcohol compounds such as methanol, ethanol and isopropyl alcohol; ketone compounds such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester compounds such as ethyl acetate and butyl acetate; Ether compounds, for example, aromatic compounds such as toluene and xylene. These solvents can be used alone or in combination of two or more. Ester compounds and ether compounds are preferred.

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

The coating method can be appropriately selected according to the coating liquid and the transparent substrate 3 . For example, 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, an inkjet method and the like can be mentioned.

The drying temperature is, for example, 50° C. or higher, preferably 60° C. or higher, and for example, 200° C. or lower, preferably 150° C. or lower.

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

Thereafter, when the hard coat composition contains an active energy ray-curable resin, the active energy ray-curable resin is cured by irradiating with an active energy ray after drying the coating liquid.

When the hard coat composition contains a thermosetting resin, the drying step can dry the solvent and thermoset the thermosetting resin.

Next, a transparent conductive layer 5 is provided on the upper surface of the second hard coat layer 4 . For example, the transparent conductive layer 5 is formed on the upper surface of the second hard coat layer 4 by a dry method.

Dry methods include, for example, a vacuum deposition method, a sputtering method, an ion plating method, and the like. Sputtering is preferred. By this method, the transparent conductive layer 5 which is a thin film and has a uniform thickness can be formed.

In the sputtering method, a target and an adherend (transparent base material 3 with hard coat layers laminated on both sides) are placed facing each other in a vacuum chamber, gas is supplied, and a voltage is applied from a power supply to accelerate gas ions. Then, the target is irradiated, the target material is ejected from the target surface, and the target material is deposited on the adherend surface.

Examples of the sputtering method include a bipolar sputtering method, an ECR (electron cyclotron resonance) sputtering method, a magnetron sputtering method, an ion beam sputtering method, and the like. Magnetron sputtering is preferred.

When the sputtering method is employed, the target material includes the above-described metal oxides constituting the transparent conductive layer 5, and preferably ITO. From the viewpoint of the durability and crystallization of the ITO layer, the tin oxide concentration of ITO is, for example, 0.5% by mass or more, preferably 3% by mass or more, and is, for example, 15% by mass or less, preferably , 13% by mass or less.

Examples of gases include inert gases such as Ar. In addition, a reactive gas such as oxygen gas can be used together as needed.

The atmospheric pressure during sputtering is, for example, 1 Pa or less, preferably 0.7 Pa or less, or, for example, 0.1 Pa or more, from the viewpoints of suppressing a decrease in sputtering rate and discharge stability.

The power supply may be, for example, a DC power supply, an AC power supply, an MF power supply, an RF power supply, or a combination thereof.

A copper layer 6 is then provided on top of the transparent conductive layer 5 . For example, a copper layer 6 is formed on the upper surface of the transparent conductive layer 5 by a dry method.

Examples of the dry method include those described above for forming the transparent conductive layer 5, preferably sputtering. By this method, a copper layer 6 having a uniform thickness can be formed.

The sputtering conditions for the copper layer 6 are also the same as the conditions exemplified for the formation of the transparent conductive layer 5 . Preferably, in forming the copper layer 6, an inert gas is used alone as the gas. Moreover, oxygen-free copper is preferably used as the target material.

Next, an oxide film layer 7 is provided on the upper surface of the copper layer 6 . For example, an oxide film layer 7 is formed on the upper surface of the copper layer 6 by a dry method.

Examples of the dry method include those described above for forming the transparent conductive layer 5, preferably sputtering. By this method, an oxide film layer 7 having a uniform thickness can be formed.

The sputtering conditions for the oxide film layer 7 are also the same as those exemplified for the formation of the transparent conductive layer 5 . Preferably, in forming the copper layer 6, an inert gas is used alone as the gas. Moreover, as the target material, an inert gas and a reactive gas (specifically, oxygen) are used together. Oxygen-free copper is preferably used as the target material.

In particular, by adjusting the flow rate ratio between the inert gas and the reactive gas, the abundance ratio of copper hydroxide, copper oxide, and the like in the oxide film layer 7 to be formed can be adjusted. Specifically, the ratio of the reactive gas to 100 sccm of the inert gas is, for example, 3 sccm or more, preferably 5 sccm or more, more preferably 20 sccm or more, and for example, 200 sccm or less, preferably It is 100 sccm or less, more preferably 50 sccm or less.

In this way, as shown in FIG. 1, the first hard coat layer 2, the transparent base material 3, the second hard coat layer 4, the transparent conductive layer 5, the copper layer 6 and the oxide film layer 7 are formed in order from bottom to top. A provided conductive film 1 is obtained.

It should be noted that the transparent conductive layer 5 of the conductive film 1 may be subjected to crystal conversion treatment as necessary. A crystallization conversion treatment may be performed on the resulting conductive film 1, and the conductive film 1 (intermediate laminate, i.e., first It may be carried out on a laminate of hard coat layer 2/transparent substrate 3/second hard coat layer 4/transparent conductive layer 5). Moreover, you may implement with respect to the conductive film 1 after implementing patterning mentioned later.

Specifically, the conductive film 1 or the intermediate laminate is heat-treated in the air.

Heat treatment can be performed using, for example, an infrared heater, an oven, or the like.

The heating temperature is, for example, 100° C. or higher, preferably 120° C. or higher, and is, for example, 200° C. or lower, preferably 160° C. or lower. If the heating temperature is within the above range, crystal conversion can be ensured while suppressing thermal damage to the transparent substrate 3 and impurities generated from the transparent substrate 3 .

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

Thereby, a conductive film 1 having a crystallized transparent conductive layer 5 is obtained.

In the above process, each layer may be wound around a winding roll. Alternatively, the hard coat layer, the transparent conductive layer 5, the copper layer 6, and the oxide film layer 7 may be formed continuously without winding, and after the oxide film layer 7 is formed, the film may be wound around the take-up roll.

This conductive film 1 can suppress discoloration of the oxide film layer 7, which is the outermost surface layer, for a long period of time. As a result, corrosion of the copper layer 6 on the lower surface can also be suppressed for a long period of time. Therefore, the long-term storage stability is good.

9. The touch panel conductive film 1 is used, for example, as a substrate for a touch panel provided in an image display device. Examples of the type of touch panel include various types such as a capacitive type and a resistive film type, and the touch panel is particularly preferably used for a capacitive type touch panel. Specifically, for example, the patterned conductive film 1A is used as a touch panel by arranging it on a protective substrate such as protective glass.

When the conductive film 1 is used as a substrate for a touch panel, the transparent conductive layer 5, the copper layer 6 and the oxide film layer 7 are formed into desired electrode patterns, wiring patterns, etc. before or after the crystal conversion treatment, for example. pattern.

When etching the transparent conductive layer 5, the copper layer 6 and the oxide film layer 7, they may be etched simultaneously or separately, but preferably the transparent electrode layer (transparent conductive layer 5). , and the routing wiring layer (laminated body of the copper layer 6 and the oxide film layer 7) can be reliably formed in separate patterns, respectively, these are etched separately.

For example, first, the copper layer 6 and the oxide film layer 7 are arranged so that a desired wiring pattern (eg, routing wiring) is formed on the peripheral end portion (eg, the region corresponding to the routing wiring) of the copper layer 6 and the oxide film layer 7 in plan view. At the same time, the oxide film layer 7 (especially the central portion in plan view) is removed by etching. Next, the transparent conductive layer 5 exposed from the copper layer 6 and the oxide film layer 7 (especially the central portion in plan view) is removed by etching so that a desired pattern (for example, an electrode pattern in the touch input area) is formed. do.

As a result, as shown in FIG. 2, as an embodiment of the conductive film 1, a first hard coat layer 2, a transparent substrate 3, a second hard coat layer 4, a patterned transparent conductive layer 5A, a patterned copper layer 6A, Then, a patterned conductive film 1A having patterned oxide film layers 7A arranged in order from bottom to top is obtained.

The patterned copper layer 6A and the patterned oxide film layer 7A form a frame portion having a frame shape in plan view, and the patterned transparent conductive layer 5A forms a predetermined electrode pattern and wiring pattern in the patterned copper layer 6A.

The conductive film 1 is, for example, an electrophoresis method, a twist ball method, a thermal rewritable method, an optical writing liquid crystal method, a polymer dispersed liquid crystal method, a guest/host liquid crystal method, a toner display method, a chromism method, and an electric field deposition method. It can also be suitably used for flexible display elements such as systems.

<Modification>
In the embodiment shown in FIG. 1, the conductive film 1 includes a first hard coat layer 2 and a second hard coat layer 4. For example, although not shown, the conductive film 1 includes the first hard coat layer 2 and/or the second hard coat layer 4 may be omitted. Preferably, the conductive film 1 comprises a first hard coat layer 2 and a second hard coat layer 4 from the viewpoint of scratch resistance.

In the embodiment shown in FIG. 1, the conductive film 1 does not have an optical adjustment layer, but for example, although not shown, the conductive film 1 has a It can also have an optical adjustment layer disposed thereon.

In the embodiment shown in FIG. 1, the conductive film 1 does not have a transparent conductive layer 5, a copper layer 6 and an oxide layer 7 on the underside, but for example, although not shown, the conductive film 1 has a second A transparent conductive layer 5, a copper layer 6 and an oxide film layer 7 may be provided in this order on the lower surface of the hard coat layer 4.

EXAMPLES Examples and comparative examples are shown below to describe the present invention more specifically. It should be noted that the present invention is by no means limited to Examples and Comparative Examples. Specific numerical values such as the mixing ratio (content ratio), physical property values, parameters, etc. used in the following description are described in the above "Mode for Carrying Out the Invention", the corresponding mixing ratio (content ratio ), physical property values, parameters, etc. can.

(Example 1)
A 100 μm-thick cycloolefin polymer film (COP film, “ZEONOR” manufactured by Nippon Zeon Co., Ltd.) was prepared as a long transparent substrate.

UV-curable acrylic resin (manufactured by DIC, "Unidic RS29-120") 100 parts by mass, crosslinked polymethyl methacrylate particles (manufactured by Sekisui Jushi, "SSX105", average particle size 2 μm) 0.07 mass and ethyl acetate were mixed to prepare a hard coat composition coating solution. The hard coat composition coating solution was applied to both surfaces of the COP film, dried by heating, and irradiated with ultraviolet rays. As a result, hard coat layers having a thickness of 1.3 μm were formed on both sides of the COP film to obtain a laminate consisting of the first hard coat layer/transparent substrate/second hard coat layer.

Next, the laminate is placed in a roll-up sputtering apparatus, the total pressure is adjusted to 0.2 to 0.4 Pa, and an amorphous ITO layer having a thickness of 25 nm is formed on the upper surface of the second hard coat layer. , a copper layer with a thickness of 50 nm, and an oxide film layer with a thickness of 10 nm were sequentially formed.

Specifically, in the formation of the amorphous ITO layer, 98% argon gas and 2% oxygen gas were introduced into the apparatus, and an ITO target made of a sintered body of 97% by mass indium oxide and 3% by mass tin oxide was prepared. was used.

In the formation of the copper layer, 100% argon gas was introduced and a Cu target made of oxygen-free copper was used.

In forming the oxide film layer, 48 sccm of oxygen gas was introduced into 800 sccm of argon gas, and a Cu target made of oxygen-free copper was used.

Thus, a roll-shaped conductive film was produced.

(Example 2)
A conductive film was produced in the same manner as in Example 1, except that the output during sputtering was adjusted during the formation of the oxide film so that the thickness of the oxide film layer was 5 nm.

(Example 3)
A conductive film was produced in the same manner as in Example 1, except that when forming the oxide film, the output during sputtering was adjusted, the amount of oxygen introduced was 80 sccm, and the thickness of the oxide film layer was 5 nm. bottom.

(Comparative example 1)
A conductive film was produced in the same manner as in Example 1, except that when forming the oxide film, the output during sputtering was adjusted, the amount of oxygen introduced was 20 sccm, and the thickness of the oxide film layer was 5 nm. .

(Comparative example 2)
During the formation of the oxide film, except that the output during sputtering was adjusted and the amount of oxygen introduced was set to 0 sccm to form an oxygen-free copper layer, and then the oxide film layer was made to have a thickness of 2 nm by exposure to the atmosphere. A conductive film was produced in the same manner as in Example 1.

(Comparative Example 3)
In the formation of the oxide film, except that the output during sputtering was adjusted, the amount of oxygen introduced was set to 48 sccm, sputtering was performed, and then an oxide film layer having a thickness of 4 nm was formed by exposure to the atmosphere. A conductive film was produced in the same manner as in Example 1.

(Thickness of oxide film layer)
In the conductive film of each example and each comparative example, the thicknesses of the copper layer and the oxide film layer were collectively measured using a fluorescent X-ray analyzer (manufactured by Rigaku, "Primus II"). and

Next, the upper surface of the conductive film of each example and each comparative example was treated with 1 wt % hydrochloric acid for 3 minutes to remove the oxide film layer. After that, the thickness of the copper layer of this film was measured using a fluorescent X-ray spectrometer, and this thickness was defined as A2.

The thickness of the oxide film layer was calculated by subtracting A2 from A1. Table 1 shows the results.

(water contact angle)
Using a contact angle meter ("DropMaster DM500" manufactured by KYOWA Co., Ltd.), a 1.0 μL water droplet was dropped on the upper surface of the conductive film of each example and each comparative example (upper surface of the oxide film layer). Seconds later, the angle between the water droplet and the oxide film layer was measured. Table 1 shows the results.

(Surface analysis of oxide film layer)
The abundance ratio of copper hydroxide, copper (I) oxide, and copper (metal) on the upper surface of the oxide film layer of each example and each comparative example was measured using an X-ray photoelectron spectrometer. Specific conditions are shown below.

Apparatus: Quantum 2000, manufactured by ULVAC-PHI Measurement range: 200 μmφ,
Voltage: 15kV
Power: 30W
Photoelectron extraction angle: 45 degrees with respect to the sample surface Correction of binding energy: Shift correction of C1s spectrum peak position to 285 eV (long-term storage stability)
The conductive film of each example and each comparative example was stored in a roll form in an environment of 25° C. and 50% RH for 2 weeks, then unrolled from the roll form into a sheet form, and the surface of the oxide film layer was visually observed. Confirmed with

A case where discoloration was not confirmed was evaluated as ◯, and a case where discoloration was confirmed was evaluated as x. Table 1 shows the results.

1 conductive film 3 transparent substrate 5 transparent conductive layer 6 copper layer 7 oxide layer

Claims (6)

A transparent base material, a transparent conductive layer, a copper layer and an oxide film layer are provided in order in one thickness direction,
A conductive film (excluding the conductive film described below), wherein a water contact angle of the surface of the oxide film layer opposite to the copper layer is 75° or more.
a film substrate;
a first transparent conductor layer formed on one side of the film substrate;
a first copper layer formed on the opposite side of the first transparent conductor layer to the film substrate;
a second transparent conductor layer formed on the other side of the film substrate;
a second copper layer formed on the opposite side of the second transparent conductor layer to the film substrate;
and a first oxide film layer having a thickness of 1 nm to 15 nm formed on the side of the first copper layer opposite to the first transparent conductor layer and containing copper (I) oxide. the film. 2. The conductive film according to claim 1, wherein the ratio of copper hydroxide measured on the surface of the oxide film layer by X-ray photoelectron spectroscopy under the following conditions is 20 area % or less.
〔Measurement condition〕
Measurement range: 200μmφ
Voltage: 15kV
Power: 30W
Photoelectron extraction angle: 45 degrees with respect to the sample surface Correction of binding energy: Shift correction of the peak position of the C1s spectrum to 285 eV 3. The conductive film according to claim 1, wherein the surface of said oxide film layer has a copper ratio of 25 area % or less as measured by X-ray photoelectron spectroscopy under the following conditions.
〔Measurement condition〕
Measurement range: 200μmφ
Voltage: 15kV
Power: 30W
Photoelectron extraction angle: 45 degrees with respect to the sample surface Correction of binding energy: Shift correction of the peak position of the C1s spectrum to 285 eV 4. The ratio of copper (I) oxide measured on the surface of the oxide film layer by X-ray photoelectron spectroscopy under the following conditions is 40 area % or more, according to any one of claims 1 to 3. The conductive film as described in .
〔Measurement condition〕
Measurement range: 200μmφ
Voltage: 15kV
Power: 30W
Photoelectron extraction angle: 45 degrees with respect to the sample surface Correction of binding energy: Shift correction of the peak position of the C1s spectrum to 285 eV The conductive film according to any one of claims 1 to 4, wherein the oxide film layer has a thickness of 5 nm or more. A touch panel comprising the conductive film according to any one of claims 1 to 5.

Images