Conductive film, conductive film roll using the same, electronic paper, touch panel, and flat panel display

Abstract

The object of the present invention is to provide a conductive film that has improved transparency due to thinning of metal wires and further improved mechanical properties, electrical properties, and optical properties, as well as a conductive film roll, electronic paper, touch panel, and flat panel display using the same. The conductive film of the present invention has a transparent substrate and a conductive portion including a metal wire pattern arranged on one or both sides of the transparent substrate. The metal wire pattern is composed of metal wires. The metal wires contain at least any of silicon atoms Si, oxygen atoms O, and carbon atoms C in addition to conductive metal atoms M. In STEM-EDX analysis of a cross section of the metal wire perpendicular to the extension direction of the metal wire, when the maximum thickness of the metal wire is recorded as T, the metal wire contains at least any of the aforementioned silicon atoms Si, oxygen atoms O, and carbon atoms C at a predetermined ratio relative to the thickness direction.

Description

[0001] This application is a divisional application of the application with application number 201980051138.5, filed on July 30, 2019, and the invention name being conductive film, and conductive film roll, electronic paper, touch panel and flat panel display using the same. Technical Field

[0002] The present invention relates to a conductive film, and a conductive film roll, electronic paper, a touch panel, and a flat-panel display using the same. Background Art

[0003] Traditionally, transparent conductive films made of indium tin oxide (hereinafter referred to as "ITO") have been used in electronic devices such as electronic paper, touch panels, and flat-panel displays. Going forward, to further increase the added value of electronic devices, larger areas, improved responsiveness, and greater flexibility will become increasingly important. Therefore, the conductive films used in these applications are required to maintain high transmittance while also improving conductivity and flexibility.

[0004] ITO has inherently low electrical conductivity, so achieving high conductivity requires thicker films, which in turn reduces transmittance. Furthermore, thicker films are more susceptible to cracking due to deformation such as bending, curling, and flexing. Therefore, it is difficult for conductive films using ITO to simultaneously achieve high transmittance, conductivity, and flexibility.

[0005] Therefore, research and development of conductive films to replace ITO are underway, with conductive films comprising patterned metal fine wires on a transparent substrate attracting significant attention. Metal fine wires have a higher electrical conductivity than ITO, an oxide, and conductive films using them are expected to exhibit high electrical conductivity. Furthermore, metal fine wires have high ductility, resulting in conductive films using them exhibiting excellent electrical conductivity and flexibility.

[0006] Furthermore, unlike ITO, metal fine lines are opaque. However, by reducing the line width of the metal fine lines to, for example, 5 μm or less, low visibility and high transmittance can be achieved. Regarding this, Non-Patent Document 1 discloses a technique for printing metal fine lines with a minimum line width of 0.8 μm on a plastic substrate.

[0007] On the other hand, conductive films using fine metal wires have the following problem: deformation such as bending, curling, and flexing during operation and equipment installation can easily cause the fine metal wires to peel off from the transparent substrate, resulting in reduced conductivity. To address this problem, a method is known for providing a transparent electrode having a fine metal wire pattern that adheres well to the substrate, in which a porous layer is formed between a transparent resin substrate and the fine metal wire pattern, and a transparent conductive protective layer is formed on the fine metal wire pattern (for example, see Patent Document 1).

[0008] In addition, Patent Document 2 discloses that by making a metal wiring mainly composed of copper contain a second metal element such as silicon, and an alloy of copper and the second metal element forms a metal oxide film (layer) at the interface of the metal wiring, the adhesion between the metal wiring and the organic film serving as a protective film is improved, thereby improving reliability.

[0009] Prior art literature

[0010] Non-patent literature

[0011] Non-patent literature 1: Nature Communications 7, Article number: 11402

[0012] Patent Literature

[0013] Patent Document 1: International Publication No. 2014 / 034920

[0014] Patent Document 2: International Publication No. 2015 / 046261 Summary of the Invention

[0015] Problems to be solved by the invention

[0016] However, because metal wires are opaque, simply thinning them is not sufficient to address the reduction in transparency. Furthermore, as described in Non-Patent Document 1, simply thinning metal wires decreases conductivity. Therefore, there is still room for improvement in achieving both high transparency and improved conductivity.

[0017] Furthermore, if the metal wires are thinned, there is a problem that the metal wires are easily broken due to deformation such as bending, curling, and flexing. For example, the wire width of the metal wires studied in Patent Document 1 is 10 μm or more. According to the research of the present inventors, it is known that when metal wires with a wire width of 5 μm or less are used to improve the transparency required of the conductive film, even if a porous layer such as that described in Patent Document 1 is used, the effect of suppressing the peeling of the metal wires from the transparent substrate caused by deformation such as bending, curling, and flexing of the conductive film is not sufficient.

[0018] It can be speculated that this is because: for example, for metal wires with a line width of less than 5μm, the amount of conductive ink penetrating into the porous layer is small, and the contact area between the metal wires and the transparent substrate is also small. Therefore, even if a structure like that of Patent Document 1 is made, sufficient adhesion between the metal wires and the transparent substrate can be ensured.

[0019] Furthermore, although Patent Document 2 discloses improving the adhesion between an organic film serving as a protective film covering the metal thin wires and the metal thin wires, there is still room for improvement in mechanical, electrical, and optical properties required of a transparent conductive film.

[0020] The present invention is made in view of the above-mentioned problems, and its purpose is to provide a conductive film that enjoys the improved transparency brought about by the thinning of metal wires and further improves at least any one of the mechanical properties, electrical properties, and optical properties, as well as a conductive film roll, electronic paper, touch panel and flat panel display using the same.

[0021] Solutions for solving problems

[0022] The present inventors conducted intensive research to solve the above-mentioned problems. As a result, they discovered that, in a conductive thin film having fine metal wires, the above-mentioned problems can be solved by including a predetermined amount of silicon atoms Si in the fine metal wires relative to the conductive metal atoms M. This led to the completion of the first embodiment of the present invention.

[0023] That is, the first embodiment of the present invention is as follows.

[0024] [1] A conductive film comprising a transparent substrate and a conductive portion comprising a metal fine line pattern disposed on one or both surfaces of the transparent substrate.

[0025] The aforementioned metal fine line pattern is composed of metal fine lines.

[0026] The metal thin wire contains conductive metal atoms M and silicon atoms Si.

[0027] In the STEM-EDX analysis of the cross section of the metal fine wire perpendicular to the extending direction of the metal fine wire, when the maximum thickness of the metal fine wire is recorded as T, the atomic % ratio of the silicon atoms Si to the conductive metal atoms M in the thickness region of 0.10T to 0.90T from the metal fine wire interface on the transparent substrate side is Si / M 0.10～0.90 It is 0.001 or more and 0.070 or less.

[0028] [2] The conductive film according to [1], wherein the atomic % ratio Si / M in the thickness region of 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.10～0.25 It is 0.001 or more and 0.070 or less.

[0029] [3] The conductive film according to [1] or [2], wherein the atomic % ratio Si / M in the thickness region of 0.75T to 0.90T from the metal thin wire interface on the transparent substrate side is 0.75～0.90It is 0.001 or more and 0.070 or less.

[0030] [4] The conductive thin film according to any one of [1] to [3], wherein the conductive metal atoms M include at least one metal element selected from the group consisting of gold, silver, copper, and aluminum.

[0031] [5] The conductive film according to any one of [1] to [4], wherein the line width of the metal fine wire is 0.1 μm or more and 5.0 μm or less.

[0032] [6] The conductive film according to any one of [1] to [5], wherein the aspect ratio of the metal thin wires is 0.05 or more and 1.00 or less.

[0033] [7] The conductive film according to any one of [1] to [6], wherein the conductive film has a sheet resistance of 0.1 Ω / sq to 1,000 Ω / sq.

[0034] [8] The conductive film according to any one of [1] to [7], wherein the visible light transmittance of the conductive film is 80% or more and 100% or less.

[0035] [9] The conductive film according to any one of [1] to [8], wherein the conductive film has a haze of 0.01% to 5.00%.

[0036]

[10] The conductive film according to any one of [1] to [9], wherein the opening ratio of the metal fine line pattern is 80% or more and less than 100%.

[0037]

[11] The conductive film according to any one of [1] to

[10] , wherein the metal fine line pattern is a grid pattern.

[0038]

[12] The conductive film according to any one of [1] to

[10] , wherein the metal fine wire pattern is a line pattern.

[0039]

[13] The conductive film according to any one of [1] to

[12] , comprising an intermediate layer between the transparent substrate and the conductive portion.

[0040]

[14] The conductive thin film according to

[13] , wherein the intermediate layer comprises at least one selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride.

[0041]

[15] A conductive film roll, which is formed by winding the conductive film according to any one of [1] to

[14] .

[0042]

[16] An electronic paper comprising the conductive film according to any one of [1] to

[14] .

[0043]

[17] A touch panel comprising the conductive film according to any one of [1] to

[14] .

[0044]

[18] A flat panel display comprising the conductive film according to any one of [1] to

[14] .

[0045] In order to solve the above-mentioned problems, the inventors of the present invention have repeatedly conducted in-depth research and experiments, and found that by adjusting the composition of the metal wires to adjust the refractive index of the metal wires, the refractive index of the transparent substrate and the metal wires are made close, thereby further improving the transparency, thereby completing the second embodiment described in the present invention.

[0046] That is, the second embodiment of the present invention is as follows.

[0047] [1] A conductive film comprising a transparent substrate and a conductive portion comprising a metal fine line pattern disposed on one or both surfaces of the transparent substrate.

[0048] The aforementioned metal fine line pattern is composed of metal fine lines.

[0049] The metal thin wire contains conductive metal atoms M and oxygen atoms O.

[0050] In the STEM-EDX analysis of the cross section of the metal fine wire perpendicular to the extending direction of the metal fine wire, when the thickness of the metal fine wire is denoted as T, the atomic % ratio O / M of the oxygen atoms O to the conductive metal atoms M in the thickness region of 0.10T to 0.90T from the metal fine wire interface on the transparent substrate side 0.10～0.90 It is 0.01 or more and 1.00 or less.

[0051] [2] The conductive film according to [1], wherein the atomic % ratio O / M in the metal thin wires decreases from the transparent substrate side toward the thickness direction of the metal thin wires.

[0052] [3] The conductive film according to [1] or [2], wherein the atomic % ratio O / M in the thickness region from 0.75T to 0.90T from the metal thin wire interface on the transparent substrate side is 0.75～0.90 Below 0.25.

[0053] [4] The conductive film according to any one of [1] to [3], wherein the atomic % ratio O / M in the thickness region from 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.10～0.25 It is 0.05 or above.

[0054] [5] The conductive thin film according to any one of [1] to [4], wherein the conductive metal atoms M contain at least one metal element selected from the group consisting of silver, copper, and aluminum.

[0055] [6] The conductive film according to any one of [1] to [5], wherein the metal thin wires contain at least one metal oxide selected from the group consisting of cuprous oxide, cupric oxide, silver oxide, and aluminum oxide.

[0056] [7] The conductive film according to any one of [1] to [6], wherein the thin metal wires have a line width of 0.1 μm to 5.0 μm.

[0057] [8] The conductive film according to any one of [1] to [7], wherein the aspect ratio of the thin metal wires is 0.05 or more and 1.00 or less.

[0058] [9] The conductive film according to any one of [1] to [8], wherein the conductive film has a sheet resistance of 0.1 Ω / sq to 1,000 Ω / sq.

[0059]

[10] The conductive film according to any one of [1] to [9], wherein the conductive film has a visible light transmittance of 80% or more and 100% or less.

[0060]

[11] The conductive film according to any one of [1] to

[10] , wherein the conductive film has a haze of 0.01% to 5.00%.

[0061]

[12] The conductive film according to any one of [1] to

[11] , wherein the opening ratio of the metal fine wire pattern is 80% or more and less than 100%.

[0062]

[13] The conductive film according to any one of [1] to

[12] , wherein the metal fine line pattern is a mesh pattern.

[0063]

[14] The conductive film according to any one of [1] to

[12] , wherein the metal fine wire pattern is a line pattern.

[0064]

[15] The conductive film according to any one of [1] to

[14] , further comprising an intermediate layer between the transparent substrate and the conductive portion.

[0065]

[16] The conductive thin film according to

[15] , wherein the intermediate layer comprises at least one selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride.

[0066]

[17] The conductive film according to

[15] or

[16] , wherein

[0067] The refractive index of the intermediate layer is lower than that of the transparent substrate.

[0068] The theoretical refractive index of the metal thin wires in a thickness region of 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is smaller than the refractive index of the intermediate layer.

[0069]

[18] A conductive film roll obtained by winding the conductive film described in any one of [1] to

[17] .

[0070]

[19] An electronic paper comprising the conductive film according to any one of [1] to

[17] .

[0071]

[20] A touch panel comprising the conductive film according to any one of [1] to

[17] .

[0072]

[21] A flat panel display comprising the conductive film according to any one of [1] to

[17] .

[0073] In order to solve the above-mentioned problems, the inventors of the present invention have repeatedly conducted in-depth research and experiments, and found that by adjusting the atomic % ratio of conductive metal atoms M and carbon atoms C in the cross-section of the metal wire to a specific range, a conductive film with high conductivity and high adhesion between the transparent substrate and the metal wire can be obtained, thereby completing the third embodiment described in the present invention.

[0074] That is, the third embodiment of the present invention is as follows.

[0075] [1] A conductive film comprising a transparent substrate and a conductive portion comprising a metal fine line pattern disposed on one or both surfaces of the transparent substrate.

[0076] The aforementioned metal fine line pattern is composed of metal fine lines.

[0077] The metal thin wire contains conductive metal atoms M and carbon atoms C.

[0078] In the STEM-EDX analysis of the cross section of the metal thin wire perpendicular to the extending direction of the metal thin wire, when the thickness of the metal thin wire is denoted as T, the atomic % ratio C / M in the thickness region from 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.10～0.25 is 0.3 or more and 6.0 or less,

[0079] The conductive thin film has a sheet resistance of 0.1 Ω / sq or more and 500 Ω / sq or less.

[0080] [2] The conductive film according to [1], wherein the metal thin wire further contains oxygen atoms O,

[0081] The atomic % ratio O / M in the thickness region of 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.10～0.25 It is 0.05 or above.

[0082] [3] The conductive thin film according to [1] or [2], wherein the conductive metal atoms M include at least one metal element selected from the group consisting of gold, silver, copper, and aluminum.

[0083] [4] The conductive film according to any one of [1] to [3], wherein the thin metal wires have a line width of 0.1 μm to 5.0 μm.

[0084] [5] The conductive film according to any one of [1] to [4], wherein the aspect ratio of the thin metal wires is 0.05 or more and 1.00 or less.

[0085] [6] The conductive film according to any one of [1] to [5], wherein the conductive film has a visible light transmittance of 80% or more and 100% or less.

[0086] [7] The conductive film according to any one of [1] to [6], wherein the conductive film has a haze of 0.01% to 5.00%.

[0087] [8] The conductive film according to any one of [1] to [7], wherein the opening ratio of the metal fine wire pattern is 80% or more and less than 100%.

[0088] [9] The conductive film according to any one of [1] to [8], wherein the metal fine line pattern is a mesh pattern.

[0089]

[10] The conductive film according to any one of [1] to [8], wherein the metal fine wire pattern is a line pattern.

[0090]

[11] The conductive film according to any one of [1] to

[10] , further comprising an intermediate layer between the transparent substrate and the conductive portion.

[0091]

[12] The conductive thin film according to

[11] , wherein the intermediate layer comprises at least one selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride.

[0092]

[13] A conductive film roll obtained by winding the conductive film according to any one of [1] to

[12] .

[0093]

[14] An electronic paper comprising the conductive film according to any one of [1] to

[12] .

[0094]

[15] A touch panel comprising the conductive film according to any one of [1] to

[12] .

[0095]

[16] A flat panel display comprising the conductive film according to any one of [1] to

[12] .

[0096] Effects of the Invention

[0097] According to the present invention, a conductive film, a conductive film roll, electronic paper, a touch panel and a flat panel display can be provided that enjoy the improved transparency brought about by the thinning of metal wires and further improve at least any one of the mechanical properties, electrical properties and optical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] Figure 1 A plan view showing one embodiment of the conductive film of the first to third embodiments having a mesh pattern

[0099] Figure 2 A plan view showing another embodiment of the conductive film of the first to third embodiments having a mesh pattern

[0100] Figure 3 A plan view showing one embodiment of the conductive film of the first to third embodiments having a line pattern

[0101] Figure 4 A plan view showing another embodiment of the conductive film having a line pattern according to the first to third embodiments.

[0102] Figure 5 for Figure 1 A partial cross-sectional view taken along line III-III' of the conductive film is provided, which is a diagram for explaining a cross section of the metal thin wire according to the first embodiment.

[0103] Figure 6 A plan view of a metal fine line pattern for explaining the relationship between the aperture ratio and the pitch of the conductive film of the first to third embodiments having a mesh pattern.

[0104] Figure 7 A plan view of a metal fine line pattern for explaining the relationship between the aperture ratio and the pitch of the conductive film having the line pattern in the first to third embodiments.

[0105] Figure 8A plan view showing one embodiment of electronic paper including the conductive film of the first to third embodiments.

[0106] Figure 9 Partial cross-sectional view taken along line V-V' of the electronic paper of the first to third embodiments

[0107] Figure 10 A top view showing one embodiment of electronic paper having a conventional conductive film

[0108] Figure 11 A perspective view showing one embodiment of a touch panel including the conductive film of the first to third embodiments.

[0109] Figure 12 A perspective view showing another embodiment of a touch panel including the conductive film of the first to third embodiments.

[0110] Figure 13 Schematic diagram of the current collecting portion used for sheet resistance evaluation in this example

[0111] Figure 14 for Figure 1 A partial cross-sectional view taken along line III-III' of the conductive film is provided, which is a diagram for explaining a cross section of the metal thin wire according to the second embodiment.

[0112] Figure 15 for Figure 1 The partial cross-sectional view of the conductive thin film taken along line III-III' is a diagram for explaining the cross section of the thin metal wire according to the third embodiment. DETAILED DESCRIPTION

[0113] The following describes the embodiments of the present invention in detail, but the present invention is not limited thereto and various modifications can be made without departing from the spirit of the present invention. The upper limit and lower limit in each numerical range of the embodiments of the present invention can be arbitrarily combined to form any numerical range.

[0114] <<First embodiment>>

[0115] An object of the first embodiment is to provide a conductive film, a conductive film roll, electronic paper, a touch panel, and a flat panel display that have excellent conductivity and flexibility while maintaining sufficient transparency.

[0116] [First embodiment: conductive film]

[0117] The conductive film of the first embodiment is a conductive film having a transparent substrate and a conductive portion including a metal fine line pattern disposed on one or both surfaces of the transparent substrate. The metal fine line pattern is composed of metal fine lines, the metal fine lines including conductive metal atoms M and silicon atoms Si, and in STEM-EDX analysis of a cross section of the metal fine lines perpendicular to the extending direction of the metal fine lines, when the maximum thickness of the metal fine lines is denoted as T, the atomic % ratio of silicon atoms Si to the conductive metal atoms M in a thickness region of 0.10T to 0.90T from the metal fine line interface on the transparent substrate side is Si / M 0.10～0.90 It is 0.001 or more and 0.070 or less.

[0118] The conductive film of the first embodiment has excellent conductivity and flexibility by containing a predetermined amount of silicon atoms Si relative to the conductive metal atoms M in the metal wires. The conductive film of the first embodiment has excellent flexibility, and therefore can suppress the breakage of the metal wires caused by deformation such as bending. The metal wires are formed by, for example, applying or printing an ink mainly dispersed with metal particles or an ink dissolved or dispersed with a metal complex on a transparent substrate, and drying and sintering the applied or printed ink. The metal wires thus formed are in a form in which nanostructures containing conductive metal atoms M are in contact and / or bonded to each other, and this form tends to have a higher resistivity than bulk metal. In addition, in order to further improve the conductivity of the metal wires, it is important to more firmly form the contact and / or bonding between the nanostructures. Here, the inventors of the present invention have obtained the following insight: by adding a predetermined amount of silicon atoms Si to the metal, the strength of the metal is improved. Based on this insight, the inventors discovered that by adding a specified amount of silicon atoms Si relative to the conductive metal atoms M to the metal wires, the contact and bonding strength between the nanostructures containing the conductive metal atoms M will be improved, resulting in improved conductivity and flexibility of the conductive film.

[0119] In the conductive thin film of the first embodiment, the atomic % ratio of Si / M 0.10～0.90 In the conductive film of the first embodiment, the atomic % ratio of Si / M is set to 0.001 or more, and the conductivity and flexibility are excellent. 0.10～0.90 When the Si / M ratio is 0.070 or less, the decrease in conductivity caused by the silicon atoms Si hindering the electron conduction in the metal thin wire can be suppressed. 0.10～0.90 The ratio of Si / M in the conductive thin film of the first embodiment is 0.001 or more and 0.070 or less. Compared with the reduction in electronic conductivity caused by the inclusion of silicon atoms Si, the improvement in conductivity caused by the strong bonding between the conductive metal atoms M in the metal thin wires due to the inclusion of silicon atoms Si is dominant, and both conductivity and flexibility can be improved. Therefore, the conductive thin film of the first embodiment can improve both conductivity and flexibility by making the atomic % ratio of Si / M0.10～0.90 The conductivity and flexibility are excellent when the Si / M ratio is 0.001 or more and 0.070 or less. 0.10～0.90 The lower limit of Si is preferably 0.003 or more, more preferably 0.005 or more. 0.10～0.90 The upper limit value of is preferably 0.065 or less, more preferably 0.063 or less.

[0120] Regarding the above-mentioned range of the atomic % ratio Si / M of silicon atoms Si to conductive metal atoms M in the metal fine wire, it is preferable that the silicon atoms Si exist uniformly in the thickness direction of the metal fine wire, that is, the flexibility of the metal fine wire is isotropic in the cross section. As a result, there is a tendency that the wire is not easily broken even if the conductive film is bent in all directions. Therefore, the atomic % ratio Si / M in the thickness region of 0.10T to 0.25T from the metal fine wire interface on the transparent substrate side is 0.10～0.25 The lower limit of Si / M is preferably 0.001 or more, more preferably 0.003 or more, and further preferably 0.005 or more. 0.10～0.25 The upper limit of Si / M is preferably 0.070 or less, more preferably 0.065 or less, and further preferably 0.063 or less. In addition, the atomic % ratio Si / M in the thickness region of 0.75T to 0.90T from the metal thin wire interface on the transparent substrate side is 0.75～0.90 The lower limit of Si / M is preferably 0.001 or more, more preferably 0.003 or more, and further preferably 0.005 or more. 0.75～0.90 The upper limit value of is preferably 0.070 or less, more preferably 0.065 or less, and further preferably 0.063 or less.

[0121] Examples of silicon compounds include (poly)silanes, (poly)silazanes, (poly)silothianes, (poly)siloxanes, silicon, silicon carbide, silicon oxide, silicon nitride, silicon chloride, silicate, zeolite, and silicide. These polysilanes, polysilazanes, polysilothianes, and polysiloxanes may have a linear or branched, cyclic, or network-like form. These silicon compounds may be used alone or in combination of two or more.

[0122] The silicon atoms Si contained in the metal thin wires may exist in the form of silicon atoms, silicon compounds, or in the form of silicon atoms, silicon compounds bonded to conductive metal atoms M (eg, Si-M, Si-OM, etc.).

[0123] The conductive metal atoms M herein are preferably at least one metal element selected from gold, silver, copper, and aluminum, preferably silver or copper, with relatively inexpensive copper being particularly preferred. The use of such metal elements tends to improve the conductivity of the conductive film. It should be noted that the conductive metal atoms M do not include silicon atoms (Si).

[0124] In this specification, the atomic % ratio of silicon atoms Si to conductive metal atoms M obtained by STEM-EDX analysis of a cross section of the metal thin wire perpendicular to the extending direction of the metal thin wire is Si / M 0.10～0.90 、Si / M 0.10～0.25 and Si / M 0.75～0.90 It is to be determined by the following methods. Note that, from the viewpoint of preventing oxidation and contamination of the cross section of the thin metal wire, the formation of the cross section of the thin metal wire and STEM-EDX analysis described later are preferably performed in an inert atmosphere such as argon or in a vacuum.

[0125] The measurement sample is preferably made into a thin slice including the cross section of the metal fine wire perpendicular to the extension direction of the metal fine wire. Therefore, the conductive film can be embedded in a support such as epoxy resin as needed, and then a thin slice can be formed using the method described below. The method for forming the cross section of the metal fine wire is not particularly limited as long as it is a method that can suppress the damage to the cross section of the metal fine wire caused by the formation / processing of the cross section. Preferably, a processing method using an ion beam (such as BIB (Broad Ion Beam) processing method, FIB (Focused Ion Beam) processing method), precision mechanical grinding, ultrathin microtome, etc. can be used.

[0126] The cross section of the formed thin metal wire was observed using a scanning transmission electron microscope (STEM) to obtain a STEM image of the cross section of the thin metal wire. Simultaneously, elemental mapping of the cross section of the thin metal wire was measured using energy dispersive X-ray analysis (EDX).

[0127] Based on the STEM image of the cross section of the metal fine wire, the maximum thickness T from the metal fine wire interface on the transparent substrate side to the metal fine wire surface is calculated. The "maximum thickness T" mentioned here refers to the maximum thickness among the thicknesses from the metal fine wire interface on the transparent substrate side to the metal fine wire surface. In addition, the Si atomic % is calculated from the cumulative value of the EDX intensity of the K layer of silicon atoms Si in the thickness region of 0.10T to 0.90T from the metal fine wire interface on the transparent substrate side, and the M atomic % is calculated from the cumulative value of the EDX intensity of the K layer of conductive metal atoms M in the thickness region of 0.10T to 0.90T from the metal fine wire interface on the transparent substrate side, and the atomic % ratio Si / M can be calculated. 0.10～0.90 Using the same method, Si / M can also be calculated 0.10～0.25and Si / M 0.75～0.90 .

[0128] Figure 1 , a top view of a conductive film having a metal fine line pattern in a mesh pattern is shown as one embodiment of the conductive film of the first embodiment. The conductive film 10 of the first embodiment has a conductive portion 13 including a metal fine line pattern 12 on a transparent substrate 11 .

[0129] In addition to forming the conductive portion 13 on the transparent substrate 11, an extraction electrode (not shown) for connecting to a controller or the like may also be formed depending on the intended use of the conductive film 10. It should be noted that the transparent substrate 11 may have a conductive portion 13 on one side or both sides, or may have a plurality of conductive portions 13 on one side. The conductive portion 13 includes a metal fine wire pattern 12 configured in a manner that enables it to be energized or charged (charged). When the conductive film 10 of the first embodiment is assembled into an electronic device, the conductive portion 13 functions as a transparent electrode for the screen portion of electronic paper, touch panels, flat-panel displays, and the like.

[0130] 〔Transparent substrate〕

[0131] The term "transparent" in the transparent substrate means that the visible light transmittance is preferably 80% or higher, more preferably 90% or higher, and even more preferably 95% or higher. The visible light transmittance can be measured in accordance with JIS K 7361-1:1997.

[0132] The material of the transparent substrate is not particularly limited, and examples thereof include transparent inorganic substrates such as glass; transparent organic substrates such as acrylate, methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyetheretherketone, polysulfone, polyethersulfone, polyimide, and polyetherimide. Among them, by using polyethylene terephthalate, the productivity (cost reduction effect) for manufacturing the conductive film is more excellent. In addition, by using polyimide, the heat resistance of the conductive film is more excellent. Furthermore, by using polyethylene terephthalate and / or polyethylene naphthalate, the adhesion between the transparent substrate and the metal fine wire is more excellent.

[0133] The transparent substrate may be formed of a single material or may be a laminate of two or more materials. Furthermore, when the transparent substrate is a multilayer structure comprising two or more materials, the transparent substrate may be a multilayer structure comprising an organic substrate or an inorganic substrate laminated on each other, or a multilayer structure comprising an organic substrate and an inorganic substrate laminated on each other.

[0134] The thickness of the transparent substrate is preferably 5 μm or more and 500 μm or less, and more preferably 10 μm or more and 100 μm or less.

[0135] Middle layer

[0136] In addition, an intermediate layer may be provided between the transparent substrate and the conductive portion. The components contained in the intermediate layer are not particularly limited, and examples thereof include silicon compounds (such as (poly)silanes, (poly)silazanes, (poly)silothianes, (poly)siloxanes, silicon, silicon carbide, silicon oxide, silicon nitride, silicon chloride, silicate, zeolite, silicide, etc.), aluminum compounds (such as aluminum oxide, etc.), magnesium compounds (such as magnesium fluoride), etc. Among them, at least one selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide and magnesium fluoride is preferred. By using such a component, there is a tendency for the transparency and durability of the conductive film to be further improved, and the productivity (cost reduction effect) for manufacturing the conductive film is more excellent. The intermediate layer can be formed by a vapor phase film forming method such as PVD and CVD; a method of applying an intermediate forming composition in which the components contained in the above-mentioned intermediate layer are dispersed in a dispersion medium and drying it. The intermediate forming composition may contain a dispersant, a surfactant, a binder, etc. as needed.

[0137] The thickness of the intermediate layer is preferably from 0.01 μm to 500 μm, more preferably from 0.05 μm to 300 μm, and even more preferably from 0.10 μm to 200 μm. By setting the thickness of the intermediate layer to be at least 0.01 μm, adhesion between the intermediate layer and the metal wires is enhanced. If the thickness of the intermediate layer is 500 μm or less, flexibility of the transparent substrate can be ensured.

[0138] By laminating the intermediate layer on the transparent substrate, when the metal component in the ink is sintered by plasma or other sintering means, the transparent substrate in areas not covered by the metal fine line pattern can be prevented from being etched by plasma or other means.

[0139] Furthermore, in order to prevent disconnection of the metal fine wire pattern due to static electricity, the intermediate layer preferably has an antistatic function. In order to impart the antistatic function to the intermediate layer, the intermediate layer preferably contains at least one of a conductive inorganic oxide and a conductive organic compound.

[0140] The volume resistivity of the intermediate layer is preferably 100 Ωcm to 100,000 Ωcm, more preferably 1,000 Ωcm to 10,000 Ωcm, and even more preferably 2,000 Ωcm to 8,000 Ωcm. By setting the volume resistivity of the intermediate layer to 100,000 Ωcm or less, an antistatic function can be exhibited. Furthermore, by setting the volume resistivity of the intermediate layer to 100 Ωcm or greater, the intermediate layer can be suitably used in applications such as touch panels where high conductivity between metal fine line patterns is not preferred.

[0141] The volume resistivity can be adjusted by the content of the conductive inorganic oxide, conductive organic compound, etc. in the intermediate layer. For example, the intermediate layer contains silicon oxide (volume resistivity of 10 14 When using an organosilane compound as a conductive organic compound (e.g., a 100 Ω·cm or greater) and increasing the organosilane compound content, the volume resistivity can be reduced. On the other hand, increasing the silicon oxide content increases the volume resistivity, but due to its high plasma resistance, it can be formed into a thin film without compromising optical properties.

[0142] 〔Conductive part〕

[0143] The conductive portion is a metal fine line pattern disposed on a transparent substrate and composed of metal fine lines. The metal fine line pattern can be a regular pattern or an irregular pattern.

[0144] The metal wire contains conductive metal atoms M, and may contain non-conductive components in addition to the conductive components responsible for conductivity. In addition, the non-conductive components are not particularly limited, and examples thereof include metal oxides, metal compounds, and organic compounds. It should be noted that as these non-conductive components, components derived from the components contained in the ink described later can be listed, and the components are metal oxides, metal compounds, and organic compounds that remain in the metal wire after firing among the components contained in the ink. The content of the conductive component is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 70% by mass or more. The upper limit of the content of the conductive component is not particularly limited and is 100% by mass. In addition, the content of the non-conductive component is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. The lower limit of the content of the non-conductive component is not particularly limited and is 0% by mass.

[0145] (Metallic fine line pattern)

[0146] The metal fine wire pattern can be designed according to the application of the target electronic device and is not particularly limited. For example, a grid pattern ( Figure 1 and 2 ), a line pattern is formed with a plurality of substantially parallel metal thin wires ( Figure 3 and 4 ). In addition, the metal fine line pattern can be a pattern formed by combining a grid pattern and a line pattern. The grid of the grid pattern can be Figure 1 A square or rectangle as shown, or Figure 2 In addition, the metal wires constituting the line pattern may be Figure 3 The straight line shown can also be Figure 4Furthermore, the metal thin wires constituting the mesh pattern can also be formed into a curved line.

[0147] The line width W of the metal fine wires in the first embodiment refers to the line width of the metal fine wires 14 when the metal fine wires 14 are projected onto the surface of the transparent substrate 11 from the side of the transparent substrate 11 where the metal fine wire pattern 12 is arranged. Figure 5 For example, in the metal fine wire 14 having a trapezoidal cross section, the width of the surface of the metal fine wire 14 in contact with the transparent substrate 11 is the line width W. The line width W and thickness T of the metal fine wire pattern are 0.10T, 0.25T, 0.75T and 0.90T respectively. Figure 5 The pitch P is the sum of the line width W and the distance between the metal thin lines.

[0148] The line width W of the metal wire of the first embodiment is, for example, not less than 0.1 μm and not more than 5.0 μm, preferably not less than 0.2 μm and not more than 4.0 μm, more preferably not less than 0.3 μm and not more than 3.0 μm, and further preferably not less than 0.4 μm and not more than 2.5 μm. If the line width W of the metal wire is not less than 0.1 μm, the conductivity of the metal wire can be fully ensured. In addition, the reduction in conductivity caused by oxidation, corrosion, etc. on the surface of the metal wire can be fully suppressed. Furthermore, when the aperture ratio is kept the same, the thinner the line width of the metal wire, the more the number of metal wires can be increased. As a result, the electric field distribution of the conductive film becomes more uniform, and electronic devices with higher resolution can be fabricated. In addition, even if a part of the metal wire is broken, the other metal wires can compensate for the resulting impact. On the other hand, if the line width W of the metal wire is not more than 5.0 μm, there is a tendency for the visibility of the metal wire to be further reduced and the transparency of the conductive film to be further improved.

[0149] The thickness T of the metal wire is preferably not less than 10 nm and not more than 1,000 nm. The lower limit of the thickness T is more preferably not less than 50 nm, and further preferably not less than 75 nm. By making the thickness T of the metal wire not less than 10 nm, there is a tendency for the conductivity to be further improved. In addition, there is a tendency for the reduction in conductivity caused by oxidation, corrosion, etc. on the surface of the metal wire to be fully suppressed. On the other hand, by making the thickness T of the metal wire not more than 1,000 nm, high transparency can be exhibited at a wide viewing angle.

[0150] (Aspect Ratio)

[0151] The aspect ratio, represented by the thickness T of the metal fine wire relative to the wire width W of the metal fine wire, is preferably greater than or equal to 0.05 and less than or equal to 1.00. The lower limit of the aspect ratio is more preferably greater than or equal to 0.08, and further preferably greater than or equal to 0.10. By increasing the aspect ratio, there is a tendency to further improve conductivity without reducing transmittance.

[0152] (Pitch)

[0153] The pitch P of the metal fine wire pattern is preferably 5 μm or more, more preferably 50 μm or more, and further preferably 100 μm or more. By making the pitch P of the metal fine wire pattern 5 μm or more, good transmittance can be obtained. In addition, the pitch P of the metal fine wire pattern is preferably 1,000 μm or less, more preferably 500 μm or less, and further preferably 250 μm or less. By making the pitch P of the metal fine wire pattern 1,000 μm or less, there is a tendency to further improve the conductivity. It should be noted that when the shape of the metal fine wire pattern is a grid pattern, by making the pitch of the metal fine wire pattern with a line width of 1 μm 200 μm, the opening ratio can be made 99%.

[0154] It should be noted that the line width, aspect ratio and pitch of the metal fine wire pattern can be confirmed by observing the cross section of the conductive film using an electron microscope or the like. In addition, the line width and pitch of the metal fine wire pattern can also be observed using a laser microscope or an optical microscope. In addition, the pitch and the aperture ratio have a relationship described below, so if one is known, the other can be calculated. In addition, as methods for adjusting the line width, aspect ratio and pitch of the metal fine wire pattern to the desired range, there can be listed: a method of adjusting the groove of a printing plate used in the method for manufacturing the conductive film described below, a method of adjusting the average particle size of the metal particles in the ink, etc.

[0155] (Aperture ratio)

[0156] The aperture ratio of the metal fine wire pattern is preferably 60% or more, more preferably 70% or more, further preferably 80% or more, and particularly preferably 90% or more. By making the aperture ratio of the metal fine wire pattern greater than the above-mentioned specific value, there is a tendency for the transmittance of the conductive film to be further improved. In addition, the aperture ratio of the metal fine wire pattern is preferably less than 100%, more preferably less than 95%, further preferably less than 90%, further preferably less than 80%, further preferably less than 70%, and particularly preferably less than 60%. By making the aperture ratio of the metal fine wire pattern less than the above-mentioned specific value, there is a tendency for the conductivity of the conductive film to be further improved. The appropriate value of the aperture ratio of the metal fine wire pattern also varies depending on the shape of the metal fine wire pattern. In addition, the aperture ratio of the metal fine wire pattern can be appropriately combined with the above-mentioned upper limit value and lower limit value according to the required performance (transmittance and sheet resistance) of the target electronic device.

[0157] It should be noted that the "aperture ratio of the metal fine line pattern" can be calculated using the following formula for the area on the transparent substrate where the metal fine line pattern is formed. Figure 1 The range represented by S does not include edge portions where a metal fine line pattern is not formed.

[0158] Aperture ratio of metal fine line pattern

[0159] =(1-area occupied by the metal fine line pattern / area of the transparent substrate)×100

[0160] The relationship between the aperture ratio and the pitch varies depending on the shape of the metal fine line pattern and can be calculated as follows. Figure 6 A schematic diagram is shown of a mesh pattern (a grid (lattice) pattern) having pattern elements 16. In the case of this mesh pattern, the aperture ratio and the pitch have the following relationship.

[0161] Aperture ratio = {area of the opening 15 / area of the pattern unit 16} × 100

[0162] ={((pitch P1 - line width W1) × (pitch P2 - line width W2)) / (pitch P1 × pitch P2)} × 100

[0163] also, Figure 7 A schematic diagram of a line pattern is shown. In the case of this line pattern, the aperture ratio and the pitch have the following relationship.

[0164] Aperture ratio = {(pitch P - line width W) / pitch P} × 100

[0165] (Sheet resistance)

[0166] The sheet resistance of the conductive film is preferably 0.1 Ω / sq to 1,000 Ω / sq, more preferably 0.1 Ω / sq to 500 Ω / sq, even more preferably 0.1 Ω / sq to 100 Ω / sq, even more preferably 0.1 Ω / sq to 20 Ω / sq, and even more preferably 0.1 Ω / sq to 10 Ω / sq. The sheet resistance of the conductive film can be measured using the following method.

[0167] First, the portion of the conductive film where the metal fine wire pattern is arranged throughout the entire surface is cut into a rectangular shape to obtain a measurement sample. Sheet resistance measurement collectors are formed at both ends of the obtained measurement sample, electrically connected to the metal fine wire pattern. The resistance R (Ω) between the collectors provided at both ends is measured. The sheet resistance R (Ω) can be calculated using the following formula using the resistance R (Ω) and the widthwise length L (mm) and depthwise length D (mm) corresponding to the distance between the collectors of the measurement sample.s (Ω / sq).

[0168] R s =R / L×D

[0169] There is a tendency that the lower the sheet resistance, the more power loss is suppressed. Therefore, electronic paper, touch panels, and flat-panel displays with low power consumption can be obtained.

[0170] There is a tendency for the sheet resistance of the conductive thin film to be reduced by increasing the aspect ratio (height) of the metal thin wires. Alternatively, it can be adjusted by selecting the type of metal material constituting the metal thin wires.

[0171] (Visible light transmittance)

[0172] The visible light transmittance of the conductive film is preferably 80% to 100%, more preferably 90% to 100%. The visible light transmittance can be measured by calculating the transmittance in the visible light range (360 to 830 nm) from the total light transmittance according to JIS K 7361-1:1997.

[0173] There is a tendency for the visible light transmittance of the conductive thin film to increase by reducing the line width of the metal fine line pattern or increasing the aperture ratio.

[0174] (Haze)

[0175] The haze of the conductive film is preferably 0.01% to 5.00%. The upper limit of the haze is more preferably 3.00% or less, and even more preferably 1.00% or less. When the upper limit of the haze is 5.00% or less, the fogging of the conductive film in response to visible light can be sufficiently reduced. The haze herein can be measured in accordance with the haze standard of JIS K 7136:2000.

[0176] [First embodiment: Method for producing a conductive thin film]

[0177] The method for producing the conductive film of the first embodiment includes a method comprising the following steps: a patterning step of forming a pattern on a transparent substrate using an ink containing a metal component; and a firing step of firing the ink to form fine metal wires. In this case, the method for producing the conductive film of the first embodiment may include an intermediate layer forming step of forming an intermediate layer on the surface of the transparent substrate before the patterning step.

[0178] [Intermediate layer formation process]

[0179] Specific examples of the intermediate layer formation step include methods in which the intermediate layer-forming components are formed on the surface of a transparent substrate using a vapor phase film deposition method such as PVD or CVD. Another specific example of the intermediate layer formation step includes methods in which an intermediate-forming composition, in which the intermediate layer-forming components are dispersed in a dispersion medium, is applied to the surface of a transparent substrate and dried to form the intermediate layer. Components for forming the intermediate layer include those listed in the "Intermediate Layer" section. Furthermore, the intermediate layer-forming composition may contain a dispersant, a surfactant, a binder, and the like, as needed.

[0180] In the intermediate layer forming step, a silicon compound is preferably used as a component forming the intermediate layer. That is, the intermediate layer forming step is preferably a step of forming an intermediate layer containing a silicon compound on the surface of the transparent substrate before the pattern forming step. By using a silicon compound, silicon atoms can be transferred from the intermediate layer containing the silicon compound to the metal fine wires during the firing step, and therefore, there is a tendency to control the atomic % ratio Si / M within a desired range. Examples of the silicon compound include the silicon compounds exemplified in the [Intermediate Layer] section.

[0181] [Pattern Formation Process]

[0182] The pattern forming process is a process for forming a pattern using ink containing a metal component. The pattern forming process is not particularly limited as long as it involves a plate-based printing method using a plate with grooves having the desired metal fine line pattern. It may include the following steps: applying ink to the surface of a transfer medium; placing the ink-coated transfer medium surface opposite to the raised surface of a relief plate, pressing and contacting the surface to transfer the ink on the transfer medium surface to the raised surface of the relief plate; and placing the ink-coated transfer medium surface opposite to the surface of a transparent substrate, pressing and contacting the surface to transfer the ink remaining on the transfer medium surface to the surface of the transparent substrate. Note that if the transparent substrate has an intermediate layer, the ink is transferred to the surface of the intermediate layer.

[0183] (Ink)

[0184] The ink used in the pattern forming step comprises a solvent and a metal component containing conductive metal atoms M, and may also contain a surfactant, a dispersant, a reducing agent, etc. as needed. The metal component may be contained in the ink in the form of metal particles or in the form of a metal complex.

[0185] The average primary particle size of the metal particles is preferably less than 100 nm, more preferably less than 50 nm, and further preferably less than 30 nm. In addition, the lower limit of the average primary particle size of the metal particles is not particularly limited, and more than 1 nm can be listed. By making the average primary particle size of the metal particles less than 100 nm, the line width W of the obtained metal fine wire can be further narrowed. It should be noted that, in the first embodiment, the "average primary particle size" refers to the particle size of one metal particle (so-called primary particle), and is distinguished from the particle size of the aggregate (so-called secondary particle) formed by the aggregation of multiple metal particles, that is, the average secondary particle size.

[0186] The metal particles may be in the form of metal oxides such as copper oxide, metal compounds, or core / shell particles having a copper core and a copper oxide shell, as long as they contain conductive metal atoms M. The form of the metal particles can be appropriately determined from the perspectives of dispersibility and sinterability.

[0187] In the pattern forming step, the ink may contain a silicon compound in order to control the atomic % ratio Si / M within a desired range. Examples of the silicon compound include the silicon compounds exemplified in the section "Intermediate Layer."

[0188] The content of the silicon compound is preferably from 0.01 parts by mass to 10.0 parts by mass, more preferably from 0.05 parts by mass to 7.5 parts by mass, and even more preferably from 0.1 parts by mass to 5.0 parts by mass, relative to 100 parts by mass of the total amount of the ink excluding the silicon compound. By controlling the content of the silicon compound within the above range, the atomic % ratio Si / M tends to be controlled within the desired range.

[0189] The surfactant is not particularly limited, and examples thereof include fluorine-based surfactants. The use of such surfactants can improve the ink's applicability to the transfer medium (blanket) and the smoothness of the applied ink, resulting in a more uniform coating. It should be noted that the surfactant is preferably configured to disperse the metal component and to prevent residue from remaining during firing.

[0190] Dispersants are not particularly limited, and examples include those that non-covalently bond or interact with the surface of the metal component and those that covalently bond with the surface of the metal component. Examples include dispersants having a phosphate group as a functional group that non-covalently bonds or interacts. The use of such dispersants tends to further improve the dispersibility of the metal component.

[0191] Furthermore, examples of solvents include alcohol solvents such as monohydric alcohols and polyhydric alcohols; alkyl ether solvents; hydrocarbon solvents; ketone solvents; ester solvents, etc. These can be used alone or in combination of one or more. Examples include the combined use of monohydric alcohols having less than 10 carbon atoms and polyhydric alcohols having less than 10 carbon atoms. By using such solvents, there is a tendency to further improve the coating properties of the ink on the transfer medium (blanket), the transfer properties of the ink from the transfer medium to the relief plate, the transfer properties of the ink from the transfer medium to the transparent substrate, and the dispersibility of the metal component. It should be noted that the solvent is preferably constructed in a manner that can disperse the metal component and is not likely to remain after firing.

[0192] In the manufacturing method of the first embodiment, in order to control the atomic % ratio Si / M within a desired range, the medium containing the silicon compound is brought into contact with the ink during pattern formation or before firing, thereby allowing silicon atoms and silicon compounds contained in the medium to be transferred to the ink.

[0193] 〔Firing process〕

[0194] In the firing process, for example, the metal component in the ink transferred to the surface of the transparent substrate or the intermediate layer is sintered. The firing process is not particularly limited as long as the metal component is welded to form a sintered film of the metal component. The firing can be carried out in a firing furnace, for example, or using plasma, a heating catalyst, ultraviolet rays, vacuum ultraviolet rays, electron beams, infrared lamp annealing, flash lamp annealing, laser, etc. When the obtained sintered film is easily oxidized, it is preferably fired in a non-oxidizing atmosphere. In addition, when metal oxides and the like are difficult to be reduced using only a reducing agent that can be contained in the ink, it is preferably fired in a reducing atmosphere.

[0195] Non-oxidizing atmosphere refers to an atmosphere that does not contain oxidizing gases such as oxygen, and there are inert atmosphere and reducing atmosphere. Inert atmosphere refers to an atmosphere that is filled with inert gases such as argon, helium, neon, nitrogen, etc. In addition, reducing atmosphere refers to an atmosphere in which reducing gases such as hydrogen and carbon monoxide are present. These gases can be filled into a firing furnace, and the coating film (dispersion coating film) of the ink can be fired in the form of a closed system. In addition, the firing furnace can also be made into a circulation system, and the dispersion coating film can be fired while circulating these gases. When the dispersion coating film is fired in a non-oxidizing atmosphere, it is preferred that the firing furnace is temporarily vacuumed to remove the oxygen in the firing furnace, and non-oxidizing gas is utilized to replace it. In addition, firing can be carried out in a pressurized atmosphere or in a reduced pressure atmosphere.

[0196] The firing temperature is not particularly limited, but is preferably 20°C or higher and 400°C or lower, more preferably 50°C or higher and 300°C or lower, and even more preferably 80°C or higher and 200°C or lower. Setting the firing temperature to 400°C or lower allows the use of substrates with low heat resistance, which is preferred. Setting the firing temperature to 20°C or higher also allows for sufficient formation of the sintered film, which tends to improve electrical conductivity, which is preferred. It should be noted that the resulting sintered film contains a conductive component derived from the metal component, and in addition, may contain a non-conductive component depending on the components used in the ink and the firing temperature.

[0197] As described above, according to the first embodiment of the present invention, a conductive film, a conductive film roll, electronic paper, a touch panel, and a flat panel display can be provided that have excellent conductivity and flexibility while maintaining sufficient transparency.

[0198] <<Second embodiment>>

[0199] The second embodiment aims to provide a conductive film exhibiting further excellent transparency, and a conductive film roll, electronic paper, a touch panel, and a flat-panel display using the same.

[0200] [Second embodiment: conductive film]

[0201] The conductive film of the second embodiment is characterized in that it is a conductive film having a transparent substrate and a conductive portion including a metal fine line pattern arranged on one or both surfaces of the transparent substrate, the metal fine line pattern being composed of metal fine lines, the metal fine lines containing conductive metal atoms M and oxygen atoms O, and in STEM-EDX analysis of a cross section of the metal fine lines perpendicular to the extending direction of the metal fine lines, when the thickness of the metal fine lines is denoted as T, the atomic % ratio of the oxygen atoms O to the conductive metal atoms M in a thickness region of 0.10T to 0.90T from the metal fine line interface on the transparent substrate side is O / M 0.10～0.90 It is 0.01 or more and 1.00 or less.

[0202] Figure 1 , a top view of a conductive film having a metal fine line pattern in a mesh pattern is shown as one embodiment of the conductive film of the second embodiment. The conductive film 10 of the second embodiment has a conductive portion 13 including a metal fine line pattern 12 on a transparent substrate 11 .

[0203] In addition to forming the conductive portion 13 on the transparent substrate 11, an extraction electrode (not shown) for connecting to a controller or the like may also be formed depending on the intended use of the conductive film 10. It should be noted that the transparent substrate 11 may have a conductive portion 13 on one side or both sides, or may have a plurality of conductive portions 13 on one side. The conductive portion 13 includes a metal fine wire pattern 12 configured in a manner that enables it to be energized or charged (charged). When the conductive film 10 of the second embodiment is assembled into an electronic device, the conductive portion 13 functions as a transparent electrode for the screen portion of electronic paper, touch panels, flat-panel displays, and the like.

[0204] In such a conductive film, by reducing the width of the metal thin wires, the visibility of the metal thin wires can be reduced, thereby improving transparency. However, since the metal thin wires themselves are not transparent, it is difficult to achieve complete transparency.

[0205] In contrast, according to the second embodiment, by adjusting the atomic % ratio of the conductive metal atoms M and oxygen atoms O constituting the metal fine wires, the refractive index of the metal fine wires can be made close to that of the transparent substrate. By making the refractive index of the metal fine wires close to that of the transparent substrate, reflection or scattering occurring at the refractive index interface between the metal fine wires and the transparent substrate is suppressed, and haze is reduced. Thus, even when using metal fine wire patterns having, for example, the same line width and the same aperture ratio, transparency can be further improved. Furthermore, a conductive film using such metal fine wires can be produced by printing, and therefore, compared to a conductive film using ITO produced by vacuum evaporation or sputtering, it is superior in terms of low manufacturing costs and reduced environmental burden.

[0206] 〔Conductive part〕

[0207] The conductive portion is a metal fine wire pattern disposed on a transparent substrate and composed of metal fine wires. The metal fine wire pattern may be a regular pattern or an irregular pattern. In the second embodiment, the metal fine wires constituting the metal fine wire pattern are configured to have a refractive index that is relatively close to that of the transparent substrate.

[0208] However, in view of the fact that it is not easy to measure the refractive index of the extremely fine metal wire itself, in the second embodiment, as an indicator of the refractive index, the atomic % ratio O / M of oxygen atoms O relative to the conductive metal atoms M in the cross section of the metal wire perpendicular to the extension direction of the metal wire is limited to a specified ratio. That is, as the constituent elements of the metal wire, metal and metal oxide play a dominant role, so it can be considered that the conductive metal atoms M and oxygen atoms O dominate the change in the refractive index. Therefore, the atomic % ratio O / M of oxygen atoms O relative to the conductive metal atoms M is limited to a specified ratio. For example, when the conductive metal atom M is copper, the refractive index when the metal wire is entirely composed of copper is 0.60, and the refractive index when the metal wire is entirely composed of copper oxide is 2.71. Therefore, when the metal wire is composed of copper and copper oxide, it can be considered that the refractive index is adjusted between them according to their composition ratio. In addition, for example, when the conductive metal atoms M are silver or aluminum, the refractive indices of the metal wires composed entirely of these conductive metal atoms M are 0.14 (silver) and 1.34 (aluminum), respectively. When the metal wires are composed entirely of oxides of the conductive metal atoms M, the refractive indices are 2.79 (silver oxide) and 1.77 (aluminum oxide), respectively. Therefore, when the metal wires are composed of any of silver and aluminum and their oxides, it can be considered that the refractive index is adjusted between these values according to their composition ratio. It should be noted that, in the second embodiment, the refractive index value calculated based on the constituent atoms (or materials) and their composition ratio is also referred to as the theoretical refractive index.

[0209] From the above viewpoint, the atomic % ratio O / M 0.10～0.90 It is 0.01 or more and 1.00 or less, preferably 0.02 or more and 0.80 or less, and more preferably 0.03 or more and 0.75 or less. 0.10～0.90 The more it increases, the higher the refractive index of the metal wire will be. The atomic % ratio O / M 0.10～0.90 The more it decreases, the lower the refractive index of the metal wire will be. As a result, the refractive index of the metal wire approaches the refractive index of the transparent substrate, and the transparency is further improved. 0.10～0.90 The more it decreases, the more the proportion of oxides decreases, so there is a tendency for the conductivity to be further improved. 0.10～0.90 On the other hand, by making the atomic % ratio O / M 0.10～0.90 When the value is 1.00 or less, high conductivity can be exhibited while maintaining good transparency.

[0210] There are no particular restrictions on the partial presence and uniformity of oxygen atoms O in the cross section of the metal fine wire. The oxygen atoms O may be roughly uniformly distributed in the cross section of the metal fine wire, or may be, for example, partially present at the interface of the metal fine wire on the transparent substrate side, or may be partially present on the surface side of the metal fine wire (the side opposite to the transparent substrate side). The atomic % ratio O / M in the metal fine wire preferably has a tendency to decrease from the transparent substrate side toward the thickness direction of the metal fine wire. By making such a structure, there is a tendency for transparency to be further improved.

[0211] The principle behind this is not particularly limited; for example, a thin film in which optical properties such as reflectivity are controlled by stacking multiple layers with different refractive indices can be considered a model. Specifically, in the conductive film of the second embodiment, the thin metal wires whose atomic % ratio O / M decreases gradually from the transparent substrate toward the thickness of the thin metal wires can be considered to approximate the multiple layers with different refractive indices in this model. However, the principle is not limited to this.

[0212] The partial presence and uniformity of oxygen atoms O can be expressed using the atomic % ratio O / M within a specific thickness region. For example, the atomic % ratio O / M within the thickness region from 0.75T to 0.90T from the metal thin wire interface on the transparent substrate side is expressed as the atomic % ratio O / M 0.75～0.90 When the atomic % ratio O / M 0.75～0.90 It is an indicator of the ratio of oxygen atoms O present in the region on the surface side of the metal thin wire. This atomic % ratio O / M 0.75～0.90 It is preferably 0.25 or less, more preferably 0.22 or less, and further preferably 0.18 or less. 0.75～0.90 When the ratio is 0.25 or less, the conductivity tends to be further improved. It should be noted that, in the second embodiment, T refers to the maximum thickness from the metal fine wire interface on the transparent substrate side to the metal fine wire surface, which can be measured using an electron microscope photograph. It should be noted that, from the perspective of improving conductivity, the atomic % ratio O / M 0.75～0.90 The minimum value can be 0.

[0213] The atomic % ratio O / M in the thickness region from 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is referred to as the atomic % ratio O / M 0.10～0.25 When the atomic % ratio O / M 0.10～0.25 It is an indicator of the ratio of oxygen atoms O present in the region on the interface side of the metal thin wire on the transparent substrate side. 0.10～0.25 It is preferably 0.05 or more, more preferably 0.06 or more, and even more preferably 0.07 or more. 0.10～0.25 When the ratio is 0.05 or more, the transparency tends to be further improved.0.10～0.25 It is preferably 1.10 or less, more preferably 1.00 or less, and further preferably 0.95 or less. 0.10～0.25 When the ratio is 1.10 or less, the electrical conductivity tends to be further improved.

[0214] In the second embodiment, the atomic % ratio O / M 0.10～0.90 , atomic % ratio O / M 0.75～0.90 and atomic % ratio O / M 0.10～0.25 It can be obtained based on the STEM-EDX analysis of the cross section of the metal wire orthogonal to the extension direction of the metal wire. Specifically, the metal wire is cut along a direction orthogonal to the extension direction of the metal wire, and a thin slice exposing the cross section of the metal wire is obtained as a measurement sample. At this time, the conductive film can be embedded in a support such as an epoxy resin as needed, and then a thin slice is formed. The method for forming the cross section of the metal wire is not particularly limited as long as it is a method that can suppress the damage caused to the cross section by the formation / processing of the cross section. Preferably, a processing method using an ion beam (such as a BIB (Broad Ion Beam) processing method, a FIB (Focused Ion Beam) processing method), precision mechanical grinding, an ultrathin slicer, etc. can be used.

[0215] Next, a scanning transmission electron microscope (STEM) is used to observe the measurement sample obtained by the above operation to obtain a STEM image of the cross section of the metal wire. At the same time, energy dispersive X-ray analysis (EDX) is used to perform elemental mapping of the cross section of the metal wire. Specifically, the EDX intensity of the K layer of the oxygen atom O and the EDX intensity of the K layer of the conductive metal atom M are measured at each part of the cross section. This operation is performed on a thickness region of at least 0.10T to 0.90T from the metal wire interface on the transparent substrate side in the cross section of the metal wire, and the cumulative value of the EDX intensity of the K layer of the oxygen atom O and the cumulative value of the EDX intensity of the K layer of the conductive metal atom M in the region are calculated, and the ratio of these cumulative values is obtained as the atomic % ratio O / M 0.10～0.90 In addition, for the atomic % ratio O / M 0.75～0.90 , atomic % ratio O / M 0.10～0.25 , in the target thickness region, the ratio of the cumulative values is calculated using the same method.

[0216] It should be noted that the thickness T of the defined thickness region here refers to the maximum thickness from the metal wire interface on the transparent substrate side to the metal wire surface, which can be confirmed based on the STEM image of the metal wire cross section. Therefore, even in the case where the thickness of a specific portion of the same cross section of the metal wire varies due to surface roughness, etc., the maximum thickness in the cross section is thickness T. It should be noted that from the perspective of preventing oxidation and contamination of the metal wire cross section, the formation of the metal wire cross section and STEM-EDX analysis are preferably performed in an inert atmosphere such as argon or in a vacuum.

[0217] As above, by the atomic % ratio O / M 0.10～0.90 , preferably further increase the atomic % ratio O / M 0.75～0.90 , atomic % ratio O / M 0.10～0.25 By adjusting the content within a specific range, the transparency of the conductive film can be improved.

[0218] Atom % ratio O / M 0.10～0.90 , atomic % ratio O / M 0.75～0.90 , atomic % ratio O / M 0.10～0.25 The values of are not particularly limited, and their increase or decrease can be controlled by, for example, adjusting the firing conditions when forming the metal fine wires. The metal fine wires can be formed by forming a pattern on a transparent substrate using an ink containing a metal component, and firing it to bond the metal components to each other. In this firing process, it can be considered that the metal component is difficult to diffuse and aggregate while fusing with nearby metal components under oxidation or reduction conditions to form a metal component sintered film. Therefore, by adjusting the firing atmosphere and the energy during firing (such as heat, plasma, electron beams, irradiation energy of the light source), and the firing time, the oxidation and reduction of the metal component are adjusted, thereby adjusting the atomic % ratio O / M of the entire metal fine wire and the atomic % ratio O / M of the surface portion of the metal fine wire that is easily affected by oxidation or reduction. 0.75～0.90 、The atomic % ratio O / M at the interface between the metal thin wire that is less susceptible to oxidation or reduction and the transparent substrate 0.10～0.25 .

[0219] In addition, as described in the third embodiment described later, the metal wires constituting the metal wire pattern in the second embodiment can further have the following structure: in the cross section of the metal wire orthogonal to the extension direction of the metal wire, carbon atoms are concentrated at the metal wire interface on the transparent substrate side.

[0220] As described in the third embodiment, the existence of the bias is expressed as follows: in the STEM-EDX analysis of the cross section of the metal fine wire perpendicular to the extending direction of the metal fine wire, when the thickness of the metal fine wire is recorded as T, the atomic % ratio C / M in the thickness region from 0.10T to 0.25T from the metal fine wire interface on the transparent substrate side is used.0.10～0.25 To express.

[0221] Atomic % ratio C / M in the second embodiment 0.10～0.25 The atomic % ratio C / M is 0.3 or more and 6.0 or less, preferably 0.4 or more and 5.0 or less. 0.10～0.25 When the atomic % ratio C / M is 0.3 or more, the adhesion of the metal thin wire to the transparent substrate is further improved. 0.10～0.25 When the ratio is 6.0 or less, not only the conductivity is further improved, but also the bonding between the conductive metal atoms M, more specifically, the bonding between the metal components becomes stronger, and the strength of the metal thin wire is improved.

[0222] From the same viewpoint as above, the atomic % ratio O / M in the thickness region from 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.10～0.25 It is preferably 0.05 or more, more preferably 0.06 or more, and even more preferably 0.07 or more. 0.10～0.25 When the ratio O / M is 0.05 or more, there is a tendency that the adhesion of the metal thin wire to the transparent substrate is further improved. 0.10～0.25 It is preferably 1.10 or less, more preferably 1.00 or less, and further preferably 0.95 or less. 0.10～0.25 When the ratio is 1.10 or less, the electrical conductivity tends to be further improved.

[0223] Atom % ratio C / M 0.10～0.25 and atomic % ratio O / M 0.10～0.25 The determination method of C / M 0. 10 ～0.25 and atomic % ratio O / M 0.10～0.25 The method of adjusting the values of is described in detail in the third embodiment.

[0224] As above, by calculating the atomic % ratio C / M 0.10～0.25 , preferably further increase the atomic % ratio O / M 0.10～0.25 Adjusting the thickness to a specific range can maintain high conductivity while improving adhesion, and can suppress the peeling of the metal wires from the transparent substrate caused by deformation such as bending, curling, and flexing of the conductive film. In addition, it allows the use of thin metal wires, thereby maintaining low visibility.

[0225] As described in the first embodiment, the metal thin wires constituting the metal thin wire pattern in the second embodiment have a Si / M atomic % ratio of 1:1 to 1:1 in order to improve conductivity and flexibility. 0.10～0.90 The atomic % ratio Si / M can be 0.001 or more and 0.070 or less. 0.10～0.90The lower limit of Si is preferably 0.003 or more, more preferably 0.005 or more. 0.10～0.90 The upper limit value of is preferably 0.065 or less, more preferably 0.063 or less.

[0226] Furthermore, the atomic % ratio Si / M in the thickness region of 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.10～0.25 The lower limit of Si / M is preferably 0.001 or more, more preferably 0.003 or more, and further preferably 0.005 or more. 0.10～0.25 The upper limit of Si / M is preferably 0.070 or less, more preferably 0.065 or less, and further preferably 0.063 or less. In addition, the atomic % ratio Si / M in the thickness region of 0.75T to 0.90T from the metal thin wire interface on the transparent substrate side is 0.75～0.90 The lower limit of Si / M is preferably 0.001 or more, more preferably 0.003 or more, and further preferably 0.005 or more. 0.75～0.90 The upper limit of is preferably 0.070 or less, more preferably 0.065 or less, and further preferably 0.063 or less. Thus, there is a tendency that the conductive film is less likely to break even when bent in any direction.

[0227] The conductive metal atoms M preferably include at least one metal element selected from silver, copper, and aluminum, preferably silver or copper, and particularly preferably relatively inexpensive copper. The use of such metal elements tends to improve the conductivity of the conductive film.

[0228] Furthermore, oxygen atoms O may be included in the metal wires as oxygen atoms constituting a metal oxide. Such metal oxides are not particularly limited, and examples thereof include at least one selected from the group consisting of cuprous oxide, cupric oxide, silver oxide, and aluminum oxide. From the perspective of manufacturing processes, the metal atoms constituting the metal oxide are preferably the same as the conductive metal atoms M.

[0229] Furthermore, the metal wire contains conductive metal atoms M, and may contain non-conductive components in addition to the conductive components responsible for conductivity. As non-conductive components, there are no particular restrictions, and in addition to the above-mentioned metal oxides, there can be cited metal compounds, components derived from components contained in the ink described later, and organic compounds that remain in the metal wire after firing among the components contained in the ink. The content of the conductive component is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 70% by mass or more. The upper limit of the content of the conductive component is not particularly limited and is 100% by mass. In addition, the content of the non-conductive component is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. The lower limit of the content of the non-conductive component is not particularly limited and is 0% by mass.

[0230] The theoretical refractive index of the metal wire in the thickness range of 0.10T to 0.25T from the metal wire interface on the transparent substrate side is preferably 0.30 to 1.45, more preferably 0.40 to 1.35, and even more preferably 0.50 to 1.30. By making the theoretical refractive index of the metal wire within the above range, there is a tendency for transparency to be further improved. As described above, the theoretical refractive index of the metal wire is a refractive index value calculated based on the constituent atoms (or materials) and their composition ratio.

[0231] (Metallic fine line pattern)

[0232] The metal fine wire pattern can be designed according to the application of the target electronic device and is not particularly limited. For example, a grid pattern ( Figure 1 and 2 ), a line pattern is formed with a plurality of substantially parallel metal thin wires ( Figure 3 and 4 ). In addition, the metal fine line pattern can be a pattern formed by combining a grid pattern and a line pattern. The grid of the grid pattern can be Figure 1 A square or rectangle as shown, or Figure 2 In addition, the metal wires constituting the line pattern may be Figure 3 The straight line shown can also be Figure 4 Furthermore, the metal thin wires constituting the mesh pattern can also be formed into a curved line.

[0233] The line width W of the thin metal wires in the second embodiment refers to the line width of the thin metal wires 14 when the thin metal wires 14 are projected onto the surface of the transparent substrate 11 from the side of the transparent substrate 11 where the thin metal wire pattern 12 is arranged. Figure 14 Show Figure 1Partial cross-sectional view of the conductive film III-III'. Figure 14 For example, in a metal wire 14 having a trapezoidal cross-section, the width of the surface of the metal wire 14 in contact with the transparent substrate 11 is the line width W. In addition, the thickness T of the metal wire refers to the maximum thickness when the surface roughness is taken into account, and the pitch P refers to the sum of the line width W and the distance between the metal wires.

[0234] (Line Width)

[0235] The line width W of the metal wire is preferably, for example, not less than 0.1 μm and not more than 5.0 μm, more preferably not less than 0.2 μm and not more than 4.0 μm, further preferably not less than 0.3 μm and not more than 3.0 μm, and further preferably not less than 0.4 μm and not more than 2.5 μm. By making the line width W of the metal wire not less than 0.1 μm, there is a tendency for the conductivity to be further improved. In addition, there is a tendency for the reduction in conductivity caused by oxidation, corrosion, etc. on the surface of the metal wire to be fully suppressed. Furthermore, when the aperture ratio is kept the same, the thinner the line width of the metal wire, the more the number of metal wires can be increased. As a result, the electric field distribution of the conductive film becomes more uniform, and electronic devices with higher resolution can be produced. In addition, even if a part of the metal wire is broken, the other metal wires can compensate for the resulting impact. On the other hand, by making the line width W of the metal wire not more than 5.0 μm, there is a tendency for the visibility of the metal wire to be further reduced and the transparency of the conductive film to be further improved.

[0236] The thickness T of the metal wire is preferably not less than 10 nm and not more than 1,000 nm. The lower limit of the thickness T is more preferably not less than 50 nm, and further preferably not less than 75 nm. By making the thickness T of the metal wire not less than 10 nm, there is a tendency for the conductivity to be further improved. In addition, there is a tendency for the reduction in conductivity caused by oxidation, corrosion, etc. on the surface of the metal wire to be fully suppressed. On the other hand, by making the thickness T of the metal wire not more than 1,000 nm, high transparency can be exhibited at a wide viewing angle.

[0237] (Aspect Ratio)

[0238] The aspect ratio, represented by the thickness T of the metal fine wire relative to the wire width W of the metal fine wire, is preferably greater than or equal to 0.05 and less than or equal to 1.00. The lower limit of the aspect ratio is more preferably greater than or equal to 0.08, and even more preferably greater than or equal to 0.10. By setting the aspect ratio to greater than or equal to 0.05, there is a tendency to further improve conductivity without reducing transmittance.

[0239] (Pitch)

[0240] The pitch P of the metal fine wire pattern is preferably 5 μm or more, more preferably 50 μm or more, and further preferably 100 μm or more. By making the pitch P of the metal fine wire pattern 5 μm or more, good transmittance can be obtained. In addition, the pitch P of the metal fine wire pattern is preferably 1,000 μm or less, more preferably 500 μm or less, and further preferably 250 μm or less. By making the pitch P of the metal fine wire pattern 1,000 μm or less, there is a tendency to further improve the conductivity. It should be noted that when the shape of the metal fine wire pattern is a grid pattern, by making the pitch of the metal fine wire pattern with a line width of 1 μm 200 μm, the opening ratio can be made 99%.

[0241] It should be noted that the line width, aspect ratio and pitch of the metal fine wire pattern can be confirmed by observing the cross section of the conductive film using an electron microscope or the like. In addition, the line width and pitch of the metal fine wire pattern can also be observed using a laser microscope or an optical microscope. In addition, the pitch and the aperture ratio have a relationship as described below, so if one is known, the other can be calculated. In addition, as methods for adjusting the line width, aspect ratio and pitch of the metal fine wire pattern to the desired range, there can be listed: a method of adjusting the grooves of the plate used in the method for manufacturing the conductive film described below, a method of adjusting the average particle size of the metal particles in the ink, etc.

[0242] (Aperture ratio)

[0243] The lower limit of the aperture ratio of the metal fine wire pattern is preferably 60% or more, more preferably 70% or more, further preferably 80% or more, and particularly preferably 90% or more. By making the aperture ratio of the metal fine wire pattern greater than the above-mentioned specific value, there is a tendency for the transmittance of the conductive film to be further improved. In addition, the upper limit of the aperture ratio of the metal fine wire pattern is preferably less than 100%, more preferably less than 95%, further preferably less than 90%, further preferably less than 80%, further preferably less than 70%, and particularly preferably less than 60%. By making the aperture ratio of the metal fine wire pattern less than the above-mentioned specific value, there is a tendency for the conductivity of the conductive film to be further improved. The appropriate value of the aperture ratio of the metal fine wire pattern also varies depending on the shape of the metal fine wire pattern. In addition, the aperture ratio of the metal fine wire pattern can be appropriately combined with the above-mentioned upper limit and lower limit according to the required performance (transmittance and sheet resistance) of the target electronic device.

[0244] It should be noted that the "aperture ratio of the metal fine line pattern" can be calculated using the following formula for the area on the transparent substrate where the metal fine line pattern is formed. Figure 1 The range represented by S does not include edge portions where a metal fine line pattern is not formed.

[0245] Aperture ratio = (1-area occupied by metal fine line pattern / area of transparent substrate) × 100

[0246] The relationship between the aperture ratio and the pitch varies depending on the shape of the metal fine line pattern and can be calculated as follows. Figure 6 A schematic diagram is shown of a mesh pattern (a grid (lattice) pattern) having pattern elements 16. In the case of this mesh pattern, the aperture ratio and the pitch have the following relationship.

[0247] Aperture ratio = {area of the opening 15 / area of the pattern unit 16} × 100

[0248] ={((pitch P1 - line width W1) × (pitch P2 - line width W2)) / (pitch P1 × pitch P2)} × 100

[0249] also, Figure 7 A schematic diagram of a line pattern is shown. In the case of this line pattern, the aperture ratio and the pitch have the following relationship.

[0250] Aperture ratio = {(pitch P - line width W) / pitch P} × 100

[0251] (Sheet resistance)

[0252] The sheet resistance of the conductive film is preferably 0.1Ω / sq or more and 1,000Ω / sq or less, more preferably 0.1Ω / sq or more and 500Ω / sq or less, further preferably 0.1Ω / sq or more and 100Ω / sq or less, further preferably 0.1Ω / sq or more and 20Ω / sq or less, and further preferably 0.1Ω / sq or more and 10Ω / sq or less. There is a tendency that the lower the sheet resistance, the more suppressed the power loss. Therefore, by using a conductive film with low sheet resistance, electronic paper, touch panel and flat panel display with low power consumption can be obtained. The sheet resistance of the conductive film can be measured by the following method.

[0253] Figure 13 A three-dimensional diagram is shown to illustrate the method for measuring sheet resistance. First, a portion of a conductive film having a metal fine wire pattern disposed thereon is cut into a rectangular shape to obtain a measurement sample. Collecting portions for measuring sheet resistance, electrically connected to the metal fine wire pattern, are formed at both ends of the obtained measurement sample, and the resistance R (Ω) between the collecting portions is measured. The obtained resistance R (Ω) and the distance L (mm) between the collecting portions of the measurement sample and the length D (mm) in the depth direction can be used to calculate the sheet resistance R using the following formula: s (Ω / sq).

[0254] R s =R / L×D

[0255] The sheet resistance of the conductive thin film tends to decrease as the aspect ratio (thickness) of the metal thin wire increases. Alternatively, it can be adjusted by selecting the type of metal material constituting the metal thin wire.

[0256] There is a tendency that the lower the sheet resistance, the more power loss is suppressed. Therefore, electronic paper, touch panels, and flat-panel displays with low power consumption can be obtained.

[0257] (Visible light transmittance)

[0258] The visible light transmittance of the conductive film is preferably 80% to 100%, more preferably 90% to 100%. The visible light transmittance can be measured by calculating the transmittance in the visible light range (360 to 830 nm) from the total light transmittance according to JIS K 7361-1:1997.

[0259] There is a tendency to further increase the visible light transmittance of the conductive thin film by reducing the line width of the metal fine line pattern or increasing the aperture ratio.

[0260] (Haze)

[0261] The haze of the conductive film is preferably 0.01% to 5.00%. The upper limit of the haze is more preferably 3.00% or less, and even more preferably 1.00% or less. When the upper limit of the haze is 5.00% or less, the fogging of the conductive film in response to visible light can be sufficiently reduced. The haze herein can be measured in accordance with the haze standard of JIS K 7136:2000.

[0262] 〔Transparent substrate〕

[0263] The term "transparent" in the transparent substrate means that the visible light transmittance is preferably 80% or higher, more preferably 90% or higher, and even more preferably 95% or higher. The visible light transmittance can be measured in accordance with JIS K 7361-1:1997.

[0264] The refractive index of the transparent substrate is preferably 1.50 to 1.80, more preferably 1.50 to 1.60, and even more preferably 1.55 to 1.58. By adjusting the refractive index of the transparent substrate within this range, transparency tends to be further improved. The refractive index of the transparent substrate can be measured in accordance with JIS K 7142:2014.

[0265] From the perspective of transparency, when a transparent substrate and metal wires are sequentially stacked, the refractive index preferably decreases in a stepwise manner. From this perspective, the theoretical refractive index of the metal wires within the thickness range of 0.10T to 0.25T from the metal wire interface on the transparent substrate side is preferably lower than the refractive index of the transparent substrate.

[0266] The material of the transparent substrate is not particularly limited, and examples thereof include transparent inorganic substrates such as glass; transparent organic substrates such as acrylates, methacrylates, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyetheretherketone, polysulfone, polyethersulfone, polyimide, and polyetherimide. Among them, polyethylene terephthalate, polyimide, or polyethylene naphthalate is preferred. By using polyethylene terephthalate, there is a tendency that the productivity (cost reduction effect) for manufacturing the conductive film is more excellent, and the adhesion between the transparent substrate and the metal wire is further improved. In addition, by using polyimide, there is a tendency that the heat resistance of the conductive film is further improved. Furthermore, by using polyethylene naphthalate and / or polyethylene terephthalate, there is a tendency for the adhesion between the transparent substrate and the metal thin wires to be further improved.

[0267] The transparent substrate may be formed of one material or may be a laminate of two or more materials. In addition, when the transparent substrate is a multilayer structure in which two or more materials are laminated, the transparent substrate may be a multilayer structure in which an organic substrate or an inorganic substrate is laminated on each other, or a multilayer structure in which an organic substrate and an inorganic substrate are laminated on each other.

[0268] The thickness of the transparent substrate is preferably 5 μm or more and 500 μm or less, and more preferably 10 μm or more and 100 μm or less.

[0269] Middle layer

[0270] The conductive film of the second embodiment may include an intermediate layer between the transparent substrate and the conductive portion. This intermediate layer can contribute to improving the adhesion between the transparent substrate and the metal thin wires of the conductive portion.

[0271] The components of the intermediate layer are not particularly limited, and examples thereof include silicon compounds such as (poly)silanes, (poly)silazanes, (poly)silothianes, (poly)siloxanes, silicon, silicon carbide, silicon oxide, silicon nitride, silicon chloride, silicate, zeolite, and silicide; aluminum compounds such as aluminum oxide; and magnesium compounds such as magnesium fluoride. Among these, at least one selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride is preferred. The use of such components tends to further improve the transparency and durability of the conductive film, and further enhances productivity (cost reduction) in the production of the conductive film.

[0272] The refractive index of the intermediate layer is preferably 1.30 to 1.80, more preferably 1.40 to 1.70, and even more preferably 1.45 to 1.55. By setting the refractive index of the intermediate layer within this range, transparency tends to be further improved. The refractive index of the intermediate layer can be measured in accordance with JIS K 7142:2014.

[0273] From the perspective of transparency, when stacking the transparent substrate, intermediate layer, and metal wires in this order, the refractive index preferably decreases in a stepwise manner. From this perspective, the refractive index of the intermediate layer is preferably lower than that of the transparent substrate. Furthermore, the theoretical refractive index of the metal wires within the thickness range of 0.10T to 0.25T from the metal wire interface on the transparent substrate side is preferably lower than that of the intermediate layer.

[0274] The thickness of the intermediate layer is preferably from 0.01 μm to 500 μm, more preferably from 0.05 μm to 300 μm, and even more preferably from 0.10 μm to 200 μm. By setting the thickness of the intermediate layer to be at least 0.01 μm, adhesion between the intermediate layer and the metal wires is enhanced. If the thickness of the intermediate layer is 500 μm or less, flexibility of the transparent substrate can be ensured.

[0275] By laminating the intermediate layer on the transparent substrate, when the metal component in the ink is sintered by plasma or other sintering means, the transparent substrate in areas not covered by the metal fine line pattern can be prevented from being etched by plasma or other means.

[0276] Furthermore, in order to prevent disconnection of the metal fine wire pattern due to static electricity, the intermediate layer preferably has an antistatic function. In order to impart the antistatic function to the intermediate layer, the intermediate layer preferably contains at least one of a conductive inorganic oxide and a conductive organic compound.

[0277] The volume resistivity of the intermediate layer is preferably 100 Ωcm to 100,000 Ωcm, more preferably 1,000 Ωcm to 10,000 Ωcm, and even more preferably 2,000 Ωcm to 8,000 Ωcm. By setting the volume resistivity of the intermediate layer to 100,000 Ωcm or less, an antistatic function can be exhibited. Furthermore, by setting the volume resistivity of the intermediate layer to 100 Ωcm or greater, the intermediate layer can be suitably used in applications such as touch panels where high conductivity between metal fine line patterns is not preferred.

[0278] The volume resistivity can be adjusted by the content of the conductive inorganic oxide, conductive organic compound, etc. in the intermediate layer. For example, the intermediate layer contains silicon oxide (volume resistivity of 10 14When using an organosilane compound as a conductive organic compound (e.g., a 100 Ω·cm or greater) and increasing the organosilane compound content, the volume resistivity can be reduced. On the other hand, increasing the silicon oxide content increases the volume resistivity, but due to its high plasma resistance, it can be formed into a thin film without compromising optical properties.

[0279] [Second embodiment: Method for producing a conductive thin film]

[0280] The method for producing the conductive film of the second embodiment is not particularly limited. Examples include a method comprising: a patterning step of forming a pattern on a transparent substrate using an ink containing a metal component; and a firing step of firing the pattern to form fine metal wires. Furthermore, the method for producing the conductive film of the second embodiment may include an intermediate layer forming step of forming an intermediate layer on the surface of the transparent substrate prior to the patterning step.

[0281] [Intermediate layer formation process]

[0282] The intermediate layer forming step is a step of forming an intermediate layer on the surface of a transparent substrate. The method for forming the intermediate layer is not particularly limited, and examples thereof include methods of forming a vapor-deposited film on the surface of a transparent substrate using vapor-phase film-forming methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD); and methods of forming a coating film by coating an intermediate layer-forming composition on the surface of a transparent substrate and drying the composition.

[0283] The composition for forming the intermediate layer contains the components exemplified as the components contained in the intermediate layer or their precursors, and contains a solvent, and may contain a surfactant, a dispersant, a binder, and the like as needed.

[0284] [Pattern Formation Process]

[0285] The pattern forming process is a process for forming a pattern using ink containing a metal component. The pattern forming process is not particularly limited as long as it involves a plate-based printing method using a plate with grooves having the desired metal fine line pattern. It may include the following steps: applying ink to the surface of a transfer medium; placing the ink-coated transfer medium surface opposite to the raised surface of a relief plate, pressing and contacting the surface to transfer the ink on the transfer medium surface to the raised surface of the relief plate; and placing the ink-coated transfer medium surface opposite to the surface of a transparent substrate, pressing and contacting the surface to transfer the ink remaining on the transfer medium surface to the surface of the transparent substrate. Note that if the transparent substrate has an intermediate layer, the ink is transferred to the surface of the intermediate layer.

[0286] (Ink)

[0287] The ink used in the pattern forming step comprises a solvent and a metal component containing conductive metal atoms M, and may also contain a surfactant, a dispersant, a reducing agent, etc. as needed. The metal component may be contained in the ink in the form of metal particles or in the form of a metal complex.

[0288] When metal particles are used, the average primary particle size is preferably less than 100 nm, more preferably less than 50 nm, and further preferably less than 30 nm. In addition, the lower limit of the average primary particle size of the metal particles is not particularly limited, and more than 1 nm can be listed. By making the average primary particle size of the metal particles less than 100 nm, the line width W of the obtained metal fine wire can be further narrowed. It should be noted that, in the second embodiment, the "average primary particle size" refers to the particle size of one metal particle (so-called primary particle), and is distinguished from the particle size of the aggregate (so-called secondary particle) formed by the aggregation of multiple metal particles, that is, the average secondary particle size.

[0289] The metal particles may be in the form of metal oxides such as copper oxide, metal compounds, or core / shell particles having a copper core and a copper oxide shell, as long as they contain conductive metal atoms M. The form of the metal particles can be appropriately determined from the perspectives of dispersibility and sinterability.

[0290] The surfactant is not particularly limited, and examples thereof include silicone surfactants and fluorine-based surfactants. The use of such surfactants tends to improve the ink's applicability to the transfer medium (blanket) and the smoothness of the applied ink, resulting in a more uniform coating. It should be noted that the surfactant is preferably configured to disperse the metal component and to minimize residue residue during firing.

[0291] The dispersant is not particularly limited, and examples thereof include dispersants that non-covalently bond or interact with the metal component and dispersants that covalently bond with the metal component. Examples include dispersants having a phosphate group as a functional group that non-covalently bonds or interacts. The use of such dispersants tends to further improve the dispersibility of the metal component.

[0292] Furthermore, examples of solvents include alcohol solvents such as monohydric alcohols and polyhydric alcohols; alkyl ether solvents; hydrocarbon solvents; ketone solvents; ester solvents, etc. These can be used alone or in combination of one or more. Examples include the combined use of monohydric alcohols having less than 10 carbon atoms and polyhydric alcohols having less than 10 carbon atoms. By using such solvents, there is a tendency to further improve the coating properties of the ink on the transfer medium (blanket), the transfer properties of the ink from the transfer medium to the relief plate, the transfer properties of the ink from the transfer medium to the transparent substrate, and the dispersibility of the metal component. It should be noted that the solvent is preferably constructed in a manner that can disperse the metal component and is not likely to remain after firing.

[0293] 〔Firing process〕

[0294] The firing process is a process in which the metal component in the ink having a pattern transferred to the surface of the transparent substrate or the intermediate layer is fired to form a metal fine wire, thereby obtaining a conductive portion having a metal fine wire pattern identical to the pattern obtained by applying the ink. The firing process is not particularly limited as long as the metal component is welded to form a sintered film of the metal component. The firing can be carried out in, for example, a firing furnace, or using plasma, a heating catalyst, ultraviolet rays, vacuum ultraviolet rays, electron beams, infrared lamp annealing, flash lamp annealing, laser, etc. When the obtained sintered film is easily oxidized, it is preferably fired in a non-oxidizing atmosphere. In addition, when metal oxides and the like are difficult to be reduced using only a reducing agent that can be contained in the ink, it is preferably fired in a reducing atmosphere.

[0295] A non-oxidizing atmosphere refers to an atmosphere that does not contain oxidizing gases such as oxygen, and there are inert atmospheres and reducing atmospheres. Inert atmospheres refer to atmospheres that are filled with inert gases such as argon, helium, neon, and nitrogen. In addition, reducing atmospheres refer to atmospheres in which reducing gases such as hydrogen and carbon monoxide are present. These gases can be filled into a firing furnace, and the coating film (dispersion coating film) of the ink can be fired in the form of a closed system. In addition, the firing furnace can also be made into a circulation system, and the coating film can be fired while circulating these gases. When the coating film is fired in a non-oxidizing atmosphere, it is preferred that the firing furnace be temporarily vacuumed to remove the oxygen in the firing furnace, and replaced with a non-oxidizing gas. In addition, firing can be carried out in a pressurized atmosphere or in a reduced pressure atmosphere.

[0296] From the perspective of adjusting the ratio of oxygen atoms O contained in the metal thin wire interface by reducing the oxygen atoms O contained in the metal thin wire, sintering in a reducing atmosphere can be considered. Conversely, from the perspective of adjusting the ratio of oxygen atoms O contained in the metal thin wire interface by increasing the oxygen atoms O contained in the metal thin wire, sintering in a weakly reducing atmosphere or an inert atmosphere can be considered. Furthermore, under a predetermined atmosphere, the ratio of oxygen atoms O contained in the metal thin wire interface can also be adjusted by adjusting the sintering temperature and sintering time.

[0297] The firing temperature is not particularly limited, but is preferably 20°C or higher and 400°C or lower, more preferably 80°C or higher and 300°C or lower, further preferably 110°C or higher and 250°C or lower, and particularly preferably 160°C or higher and 200°C or lower. By setting the firing temperature to 400°C or lower, a substrate with low heat resistance can be used, which is preferred. In addition, by setting the firing temperature to 20°C or higher, there is a tendency for the formation of the sintered film to be fully carried out and the conductivity to become good, which is preferred. It should be noted that the resulting sintered film contains a conductive component derived from the metal component, and in addition, it may contain a non-conductive component depending on the components used in the ink and the firing temperature.

[0298] In addition, firing time is not particularly limited, is preferably more than 80 minutes and below 300 minutes, more preferably more than 100 minutes and below 250 minutes, further preferably more than 120 minutes and below 220 minutes.Be below 300 minutes by making firing time, can use the substrate with low thermotolerance, so preferably.In addition, be more than 150 minutes by making firing temperature, there is the formation that fully carries out sintered film, the good tendency that conductivity becomes, so preferably.

[0299] As described above, according to the second embodiment of the present invention, a conductive film exhibiting more excellent transparency, and a conductive film roll, electronic paper, a touch panel, and a flat panel display using the same can be provided.

[0300] <<Third embodiment>>

[0301] The third embodiment aims to provide a conductive film having both high conductivity and high adhesion between a transparent substrate and metal thin wires, and a conductive film roll, electronic paper, a touch panel, and a flat panel display using the same.

[0302] [Third embodiment: conductive film]

[0303] The conductive film of the third embodiment is characterized in that it is a conductive film having a transparent substrate and a conductive portion including a metal fine line pattern disposed on one or both surfaces of the transparent substrate. The metal fine line pattern is composed of metal fine lines, the metal fine lines including conductive metal atoms M and carbon atoms C, and in STEM-EDX analysis of a cross section of the metal fine lines perpendicular to the extending direction of the metal fine lines, when the thickness of the metal fine lines is denoted as T, the atomic % ratio C / M in a thickness region of 0.10T to 0.25T from the metal fine line interface on the transparent substrate side is 0.10～0.25 The ratio is 0.3 to 6.0, and the sheet resistance of the conductive thin film is 0.1 Ω / sq to 500 Ω / sq.

[0304] Figure 1 , a top view of a conductive film having a metal fine line pattern in a mesh pattern is shown as one embodiment of the conductive film of the third embodiment. The conductive film 10 of the third embodiment has a conductive portion 13 formed of a metal fine line pattern 12 on a transparent substrate 11.

[0305] In addition to forming the conductive portion 13 on the transparent substrate 11, an extraction electrode (not shown) for connecting to a controller or the like may also be formed depending on the intended use of the conductive film 10. It should be noted that the transparent substrate 11 may have a conductive portion 13 on one side or both sides, or may have a plurality of conductive portions 13 on one side. The conductive portion 13 is composed of a metal fine wire pattern 12 configured in a manner that enables it to be energized or charged (charged). When the conductive film 10 of the third embodiment is assembled into an electronic device, the conductive portion 13 functions as a transparent electrode for the screen portion of electronic paper, touch panels, flat-panel displays, and the like.

[0306] In such a conductive film, as the wire width of the metal wires decreases, the contact area with the transparent substrate decreases, and the metal wires are more likely to peel off from the transparent substrate due to bending, curling, or flexing of the conductive film.

[0307] In contrast, according to the third embodiment, the adhesion can be adjusted by making the metal wire interface such that carbon atoms are biased on the transparent substrate side of the metal wire cross section. Thus, from the viewpoint of transparency, the adhesion of the metal wire can be ensured even when the metal wire is thinned. In addition, in such metal wires, by making the biased presence of carbon atoms within a prescribed range, the adhesion can be ensured without compromising the conductivity. Furthermore, a conductive film using such metal wires can be produced by printing, and therefore, compared with a conductive film using ITO produced by vacuum evaporation or sputtering, it is also superior from the viewpoint of low cost in manufacturing and reduced environmental burden.

[0308] 〔Conductive part〕

[0309] The conductive portion is a metal fine wire pattern disposed on a transparent substrate and composed of metal fine wires. The metal fine wire pattern may be a regular pattern or an irregular pattern. In a third embodiment, the metal fine wires constituting the metal fine wire pattern may have a configuration such that, in a cross section of the metal fine wire orthogonal to the direction in which the metal fine wire extends, carbon atoms are disproportionately located at the metal fine wire interface on the transparent substrate side.

[0310] In the third embodiment, the existence of the partial weight is expressed as follows: in the STEM-EDX analysis of the cross section of the metal fine wire perpendicular to the extension direction of the metal fine wire, when the thickness of the metal fine wire is recorded as T, the atomic % ratio C / M in the thickness region of 0.10T to 0.25T from the metal fine wire interface on the transparent substrate side is used. 0.10～0.25 The atomic % ratio C / M in the third embodiment is represented by 0.10～0.25 The atomic % ratio C / M is 0.3 or more and 6.0 or less, preferably 0.4 or more and 5.0 or less. 0.10～0.25 When the atomic % ratio C / M is 0.3 or more, the adhesion of the metal thin wire to the transparent substrate is further improved. 0.10～0.25 When the ratio is 6.0 or less, not only the conductivity is further improved, but also the bonding between the conductive metal atoms M, more specifically, the bonding between the metal components becomes stronger, and the strength of the metal thin wire is improved.

[0311] The principle is not particularly limited, and for example, it can be considered as follows. When two components such as a transparent substrate and a metal wire with different mechanical properties such as rigidity and ductility are deformed by bending, curling, flexing, etc., as in the conductive film of the third embodiment, stress is concentrated on the interface thereof, and the metal wire may be peeled off due to repeated deformation. In this case, by making the carbon atoms predominantly present near the interface of the metal wire on the transparent substrate side, chemical bonds such as hydrogen bonds and covalent bonds are generated between the functional groups derived from carbon atoms at the interface of the metal wire and the functional groups on the surface of the transparent substrate, thereby further improving the adhesion. In addition, the carbon atoms in the metal wire become the cause of hindering electron conduction, but by forming a structure in which the carbon atoms predominantly exist near the interface of the metal wire on the transparent substrate side, good conductivity can also be exhibited at the same time.

[0312] From the same viewpoint as above, the atomic % ratio O / M in the thickness region of 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.10～0.25 It is preferably 0.05 or more, more preferably 0.06 or more, and even more preferably 0.07 or more. 0.10～0.25 When the ratio O / M is 0.05 or more, there is a tendency that the adhesion of the metal thin wire to the transparent substrate is further improved.0.10～0.25 It is preferably 1.10 or less, more preferably 1.00 or less, and further preferably 0.95 or less. 0.10～0.25 When the ratio is 1.10 or less, the electrical conductivity tends to be further improved.

[0313] In the third embodiment, the atomic % ratio C / M 0.10～0.25 and atomic % ratio O / M 0.10～0.25 It can be obtained by STEM-EDX analysis of the cross section of the metal wire orthogonal to the extension direction of the metal wire. Specifically, the metal wire is cut along a direction orthogonal to the extension direction of the metal wire, and a thin slice exposing the cross section of the metal wire is obtained as a measurement sample. At this time, the conductive film can be embedded in a support such as an epoxy resin as needed, and then a thin slice is formed. The method for forming the cross section of the metal wire is not particularly limited as long as it is a method that can suppress the damage caused to the cross section by the formation / processing of the cross section. Preferably, a processing method using an ion beam (such as a BIB (Broad Ion Beam) processing method, a FIB (Focused Ion Beam) processing method), precision mechanical grinding, an ultrathin slicer, etc. can be used.

[0314] Next, a scanning transmission electron microscope (STEM) is used to observe the measurement sample obtained by the above operation to obtain a STEM image of the cross section of the metal wire. At the same time, energy dispersive X-ray analysis (EDX) is used to perform elemental mapping of the cross section of the metal wire. Specifically, the EDX intensity of the K layer of the carbon atom C and the EDX intensity of the K layer of the conductive metal atom M are measured at each part of the cross section. This operation is performed on a thickness region of at least 0.10T to 0.25T from the metal wire interface on the transparent substrate side in the cross section of the metal wire, and the cumulative value of the EDX intensity of the K layer of the carbon atom C and the cumulative value of the EDX intensity of the K layer of the conductive metal atom M in the region are calculated, and the ratio of these cumulative values is obtained as the atomic % ratio C / M 0.10～0.25 . For atomic % ratio O / M 0.10～0.25 , can also be calculated by the same method.

[0315] It should be noted that the thickness T of the defined thickness region here refers to the maximum thickness from the metal wire interface on the transparent substrate side to the metal wire surface, which can be confirmed based on the STEM image of the metal wire cross section. Therefore, even in the case where the thickness of a specific portion of the same cross section of the metal wire varies due to surface roughness, etc., the maximum thickness in the cross section is thickness T. It should be noted that from the perspective of preventing oxidation and contamination of the metal wire cross section, the formation of the metal wire cross section and STEM-EDX analysis are preferably performed in an inert atmosphere such as argon or in a vacuum.

[0316] As above, by calculating the atomic % ratio C / M 0.10～0.25 , preferably further increase the atomic % ratio O / M 0.10～0 Adjusting the ratio of .25 to a specific range can maintain high conductivity while improving adhesion, and can prevent the metal wires from peeling off from the transparent substrate due to deformation such as bending, curling, and flexing of the conductive film. In addition, this allows the use of thin metal wires, thereby maintaining low visibility.

[0317] Atom % ratio C / M 0.10～0.25 and atomic % ratio O / M 0.10～0.25 There is no particular limitation on the values of , and their increase or decrease can be controlled by, for example, adjusting the firing conditions when forming the metal fine wires. The metal fine wires can be formed by forming a pattern on a transparent substrate using an ink containing a metal component and firing it to bond the metal components to each other. It can be considered that before the firing process, the metal component initially exists in a state of having an oxide, an oxide film, or coexisting with an organic matter such as a dispersant, but as the firing proceeds, oxygen, oxide films, organic matter, etc. are removed. It can generally be considered that the removal of oxygen, oxide films, and organic matter is easy to carry out on the gas-solid interface side of the metal fine wire (or the gas-liquid interface in the case of the ink state), and is relatively difficult to carry out inside the metal fine wire, that is, near the interface of the metal fine wire on the transparent substrate side. Therefore, by adjusting the energy during firing (such as heat, plasma, electron beam, irradiation energy of the light source), the firing time, and the reducing nature of the firing atmosphere to adjust the degree of removal of oxygen, oxide films, and organic matter, it is possible to adjust the atomic % ratio that is predominantly present near the interface of the metal fine wire on the transparent substrate side. Furthermore, by adjusting the types and contents of the surfactant, dispersant, and reducing agent contained in the ink, it is also possible to adjust the atomic % ratio of the surfactant, dispersant, and reducing agent that are concentrated near the interface of the metal thin wires on the transparent substrate side.

[0318] Furthermore, as described in the second embodiment, the metal thin wires constituting the metal thin wire pattern in the third embodiment may be configured to have a refractive index relatively close to that of the transparent substrate.

[0319] As described in the second embodiment, as an index of the refractive index, a predetermined ratio O / M of the atomic % of oxygen atoms O to the conductive metal atoms M in a cross section of the metal thin wire perpendicular to the extending direction of the metal thin wire is used.

[0320] Atom % ratio O / M in the second embodiment 0.10～0.90 It is 0.01 or more and 1.00 or less, preferably 0.02 or more and 0.80 or less, and more preferably 0.03 or more and 0.75 or less. 0.10～0.90 The more it increases, the higher the refractive index of the metal wire will be. The atomic % ratio O / M 0.10～0.90The more it decreases, the lower the refractive index of the metal wire will be. As a result, the refractive index of the metal wire approaches the refractive index of the transparent substrate, and the transparency is further improved. 0.10～0.90 The more it decreases, the more the proportion of oxides decreases, so there is a tendency for the conductivity to be further improved. 0.10～0.90 On the other hand, by making the atomic % ratio O / M 0.10～0.90 When the value is 1.00 or less, high conductivity can be exhibited while maintaining good transparency.

[0321] In addition, the partial presence and uniformity of oxygen atoms O can be expressed using the atomic % ratio O / M in a specific thickness region. For example, the atomic % ratio O / M in the thickness region from 0.75T to 0.90T from the metal thin wire interface on the transparent substrate side is expressed as the atomic % ratio O / M 0.75～0.90 When the atomic % ratio O / M 0.75～0.90 It is an indicator of the ratio of oxygen atoms O present in the region on the surface side of the metal thin wire. This atomic % ratio O / M 0.75～0.90 It is preferably 0.25 or less, more preferably 0.22 or less, and further preferably 0.18 or less. 0.75～0.90 It should be noted that in the second embodiment, T refers to the maximum thickness from the metal thin wire interface on the transparent substrate side to the metal thin wire surface, which can be measured using an electron microscope photograph.

[0322] Furthermore, the atomic % ratio O / M in the thickness region from 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is referred to as the atomic % ratio O / M 0.10～0.25 When the atomic % ratio O / M 0.10～0.25 It is an indicator of the ratio of oxygen atoms O present in the region on the interface side of the metal thin wire on the transparent substrate side. 0.10～0.25 It is preferably 0.05 or more, more preferably 0.06 or more, and even more preferably 0.07 or more. 0.10～0.25 When the ratio is 0.05 or more, the transparency tends to be further improved. 0.10～0.25 It is preferably 1.10 or less, more preferably 1.00 or less, and further preferably 0.95 or less. 0.10～0.25 When the ratio is 1.10 or less, the electrical conductivity tends to be further improved.

[0323] Atom % ratio O / M 0.10～0.90 , atomic % ratio O / M 0.75～0.90 and atomic % ratio O / M 0.10～0.25The determination method of the atomic % ratio O / M 0.10～0.90 , atomic % ratio O / M 0.75～0.90 , atomic % ratio O / M 0.10～0.25 The method of adjusting each value of will be described in detail in the second embodiment.

[0324] As above, by the atomic % ratio O / M 0.10～0.90 , preferably further increase the atomic % ratio O / M 0.75～0.90 , atomic % ratio O / M 0.10～0.25 By adjusting the content within a specific range, the transparency of the conductive film can be improved.

[0325] As described in the first embodiment, the metal thin wires constituting the metal thin wire pattern in the third embodiment have a Si / M atomic % ratio of 1:1 to 1:1 in order to improve conductivity and flexibility. 0.10～0.90 The atomic % ratio Si / M can be 0.001 or more and 0.070 or less. 0.10～0.90 The lower limit of Si is preferably 0.003 or more, more preferably 0.005 or more. 0.10～0.90 The upper limit value of is preferably 0.065 or less, more preferably 0.063 or less.

[0326] Furthermore, the atomic % ratio Si / M in the thickness region of 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.10～0.25 The lower limit of Si / M is preferably 0.001 or more, more preferably 0.003 or more, and further preferably 0.005 or more. 0.10～0.25 The upper limit of Si / M is preferably 0.070 or less, more preferably 0.065 or less, and further preferably 0.063 or less. In addition, the atomic % ratio Si / M in the thickness region of 0.75T to 0.90T from the metal thin wire interface on the transparent substrate side is 0.75～0.90 The lower limit of Si / M is preferably 0.001 or more, more preferably 0.003 or more, and further preferably 0.005 or more. 0.75～0.90 The upper limit of is preferably 0.070 or less, more preferably 0.065 or less, and further preferably 0.063 or less. Thus, there is a tendency that the conductive film is less likely to break even when bent in any direction.

[0327] The conductive metal atoms M preferably include at least one metal element selected from gold, silver, copper, and aluminum, preferably silver or copper, and particularly preferably relatively inexpensive copper. The use of such metal elements tends to improve the conductivity of the conductive film.

[0328] Furthermore, the metal wire contains the above-mentioned conductive metal atoms M, and may contain non-conductive components on the basis of containing conductive components that bear conductivity. In addition, as non-conductive components, there are no particular restrictions, and examples thereof include metal oxides, metal compounds, and organic compounds. It should be noted that as these non-conductive components, there are components derived from the components contained in the ink described later, and the components are metal oxides, metal compounds, and organic compounds that remain in the metal wire after firing among the components contained in the ink. The content ratio of the conductive component is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 70% by mass or more. The upper limit of the content ratio of the conductive component is not particularly limited, and is 100% by mass. In addition, the content ratio of the non-conductive component is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. The lower limit of the content ratio of the non-conductive component is not particularly limited, and is 0% by mass.

[0329] (Metallic fine line pattern)

[0330] The metal fine wire pattern can be designed according to the application of the target electronic device and is not particularly limited. For example, a grid pattern ( Figure 1 and 2 ), a line pattern is formed with a plurality of substantially parallel metal thin wires ( Figure 3 and 4 ). In addition, the metal fine line pattern can be a pattern formed by combining a grid pattern and a line pattern. The grid of the grid pattern can be Figure 1 A square or rectangle as shown, or Figure 2 In addition, the metal wires constituting the line pattern may be Figure 3 The straight line shown can also be Figure 4 Furthermore, the metal thin wires constituting the mesh pattern can also be formed into a curved line.

[0331] The line width W of the metal thin wires in the third embodiment refers to the line width of the metal thin wires 14 when the metal thin wires 14 are projected onto the surface of the transparent substrate 11 from the side of the transparent substrate 11 where the metal thin wire pattern 12 is arranged. Figure 15 Show Figure 1 Partial cross-sectional view of the conductive film III-III'. Figure 15 For example, in a metal wire 14 having a trapezoidal cross-section, the width of the surface of the metal wire 14 in contact with the transparent substrate 11 is the line width W. In addition, the thickness T of the metal wire refers to the maximum thickness when the surface roughness is taken into account, and the pitch P refers to the sum of the line width W and the distance between the metal wires.

[0332] (Line Width)

[0333] The line width W of the metal wire is preferably, for example, not less than 0.1 μm and not more than 5.0 μm, more preferably not less than 0.2 μm and not more than 4.0 μm, further preferably not less than 0.3 μm and not more than 3.0 μm, and further preferably not less than 0.4 μm and not more than 2.5 μm. By making the line width W of the metal wire not less than 0.1 μm, there is a tendency for the conductivity to be further improved. In addition, there is a tendency for the reduction in conductivity caused by oxidation, corrosion, etc. on the surface of the metal wire to be fully suppressed. Furthermore, when the aperture ratio is kept the same, the thinner the line width of the metal wire, the more the number of metal wires can be increased. As a result, the electric field distribution of the conductive film becomes more uniform, and electronic devices with higher resolution can be produced. In addition, even if a part of the metal wire is broken, the other metal wires can compensate for the resulting impact. On the other hand, by making the line width W of the metal wire not more than 5.0 μm, there is a tendency for the visibility of the metal wire to be further reduced and the transparency of the conductive film to be further improved.

[0334] The thickness T of the metal wire is preferably not less than 10 nm and not more than 1,000 nm. The lower limit of the thickness T is more preferably not less than 50 nm, and further preferably not less than 75 nm. By making the thickness T of the metal wire not less than 10 nm, there is a tendency for the conductivity to be further improved. In addition, there is a tendency for the reduction in conductivity caused by oxidation, corrosion, etc. on the surface of the metal wire to be fully suppressed. On the other hand, by making the thickness T of the metal wire not more than 1,000 nm, high transparency can be exhibited at a wide viewing angle.

[0335] (Aspect Ratio)

[0336] The aspect ratio, represented by the thickness T of the metal fine wire relative to the wire width W of the metal fine wire, is preferably greater than or equal to 0.05 and less than or equal to 1.00. The lower limit of the aspect ratio is more preferably greater than or equal to 0.08, and even more preferably greater than or equal to 0.10. By setting the aspect ratio to greater than or equal to 0.05, there is a tendency to further improve conductivity without reducing visible light transmittance.

[0337] (Pitch)

[0338] The pitch P of the metal fine wire pattern is preferably 5 μm or more, more preferably 50 μm or more, and further preferably 100 μm or more. By making the pitch P of the metal fine wire pattern 5 μm or more, good transmittance can be obtained. In addition, the pitch P of the metal fine wire pattern is preferably 1,000 μm or less, more preferably 500 μm or less, and further preferably 250 μm or less. By making the pitch P of the metal fine wire pattern 1,000 μm or less, there is a tendency to further improve the conductivity. It should be noted that when the shape of the metal fine wire pattern is a grid pattern, by making the pitch of the metal fine wire pattern with a line width of 1 μm 200 μm, the opening ratio can be made 99%.

[0339] It should be noted that the line width, aspect ratio and pitch of the metal fine wire pattern can be confirmed by observing the cross section of the conductive film using an electron microscope or the like. In addition, the line width and pitch of the metal fine wire pattern can also be observed using a laser microscope or an optical microscope. In addition, the pitch and the aperture ratio have a relationship as described below, so if one is known, the other can be calculated. In addition, as methods for adjusting the line width, aspect ratio and pitch of the metal fine wire pattern to the desired range, there can be listed: a method of adjusting the grooves of the plate used in the method for manufacturing the conductive film described below, a method of adjusting the average particle size of the metal particles in the ink, etc.

[0340] (Aperture ratio)

[0341] The lower limit of the aperture ratio of the metal fine wire pattern is preferably 60% or more, more preferably 70% or more, further preferably 80% or more, and particularly preferably 90% or more. By making the aperture ratio of the metal fine wire pattern greater than the above-mentioned specific value, there is a tendency for the transmittance of the conductive film to be further improved. In addition, the upper limit of the aperture ratio of the metal fine wire pattern is preferably less than 100%, more preferably less than 95%, further preferably less than 90%, further preferably less than 80%, further preferably less than 70%, and particularly preferably less than 60%. By making the aperture ratio of the metal fine wire pattern less than the above-mentioned specific value, there is a tendency for the conductivity of the conductive film to be further improved. The appropriate value of the aperture ratio of the metal fine wire pattern also varies depending on the shape of the metal fine wire pattern. In addition, the aperture ratio of the metal fine wire pattern can be appropriately combined with the above-mentioned upper limit and lower limit according to the required performance (transmittance and sheet resistance) of the target electronic device.

[0342] It should be noted that the "aperture ratio of the metal fine line pattern" can be calculated using the following formula for the area on the transparent substrate where the metal fine line pattern is formed. Figure 1 The range represented by S does not include edge portions where a metal fine line pattern is not formed.

[0343] Aperture ratio = (1-area occupied by metal fine line pattern / area of transparent substrate) × 100

[0344] The relationship between the aperture ratio and the pitch varies depending on the shape of the metal fine line pattern and can be calculated as follows. Figure 6 A schematic diagram is shown of a mesh pattern (a grid (lattice) pattern) having pattern elements 16. In the case of this mesh pattern, the aperture ratio and the pitch have the following relationship.

[0345] Aperture ratio = {area of the opening 15 / area of the pattern unit 16} × 100

[0346] ={((pitch P1 - line width W1) × (pitch P2 - line width W2)) / (pitch P1 × pitch P2)} × 100

[0347] also, Figure 7 A schematic diagram of a line pattern is shown. In the case of this line pattern, the aperture ratio and the pitch have the following relationship.

[0348] Aperture ratio = {(pitch P - line width W) / pitch P} × 100

[0349] (Sheet resistance)

[0350] The sheet resistance of the conductive film is 0.1Ω / sq or more and 500Ω / sq or less, preferably 0.1Ω / sq or more and 200Ω / sq or less, more preferably 0.1Ω / sq or more and 100Ω / sq or less, further preferably 0.1Ω / sq or more and 20Ω / sq or less, and even more preferably 0.1Ω / sq or more and 10Ω / sq or less. There is a tendency that the lower the sheet resistance, the more suppressed the power loss is. Therefore, by using a conductive film with low sheet resistance, electronic paper, touch panel and flat panel display with low power consumption can be obtained. The sheet resistance of the conductive film can be measured by the following method.

[0351] Figure 13 A three-dimensional diagram is shown to illustrate the method for measuring sheet resistance. First, a portion of a conductive film having a metal fine wire pattern disposed thereon is cut into a rectangular shape to obtain a measurement sample. Collecting portions for measuring sheet resistance, electrically connected to the metal fine wire pattern, are formed at both ends of the obtained measurement sample, and the resistance R (Ω) between the collecting portions is measured. The obtained resistance R (Ω) and the distance L (mm) between the collecting portions of the measurement sample and the length D (mm) in the depth direction can be used to calculate the sheet resistance R using the following formula: s (Ω / sq).

[0352] R s =R / L×D

[0353] The sheet resistance of the conductive thin film tends to decrease as the aspect ratio (thickness) of the metal thin wire increases. Alternatively, it can be adjusted by selecting the type of metal material constituting the metal thin wire.

[0354] There is a tendency that the lower the sheet resistance, the more power loss is suppressed. Therefore, electronic paper, touch panels, and flat-panel displays with low power consumption can be obtained.

[0355] (Visible light transmittance)

[0356] The visible light transmittance of the conductive film is preferably 80% to 100%, more preferably 90% to 100%. The visible light transmittance can be measured by calculating the transmittance in the visible light range (360 to 830 nm) from the total light transmittance according to JIS K 7361-1:1997.

[0357] There is a tendency to further increase the visible light transmittance of the conductive thin film by reducing the line width of the metal fine line pattern or increasing the aperture ratio.

[0358] (Haze)

[0359] The haze of the conductive film is preferably 0.01% to 5.00%. The upper limit of the haze is more preferably 3.00% or less, and even more preferably 1.00% or less. When the upper limit of the haze is 5.00% or less, the fogging of the conductive film in response to visible light can be sufficiently reduced. The haze herein can be measured in accordance with the haze standard of JIS K 7136:2000.

[0360] 〔Transparent substrate〕

[0361] The term "transparent" in the transparent substrate means that the visible light transmittance is preferably 80% or higher, more preferably 90% or higher, and even more preferably 95% or higher. The visible light transmittance can be measured in accordance with JIS K 7361-1:1997.

[0362] The material of the transparent substrate is not particularly limited, and examples thereof include transparent inorganic substrates such as glass; transparent organic substrates such as acrylates, methacrylates, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyetheretherketone, polysulfone, polyethersulfone, polyimide, and polyetherimide. Among them, polyethylene terephthalate, polyimide, or polyethylene naphthalate is preferred. By using polyethylene terephthalate, there is a tendency that the productivity (cost reduction effect) for manufacturing the conductive film is more excellent, and the adhesion between the transparent substrate and the metal wire is further improved. In addition, by using polyimide, there is a tendency that the heat resistance of the conductive film is further improved. Furthermore, by using polyethylene naphthalate and / or polyethylene terephthalate, there is a tendency for the adhesion between the transparent substrate and the metal thin wires to be further improved.

[0363] The transparent substrate may be formed of one material or may be a laminate of two or more materials. In addition, when the transparent substrate is a multilayer structure in which two or more materials are laminated, the transparent substrate may be a multilayer structure in which an organic substrate or an inorganic substrate is laminated on each other, or a multilayer structure in which an organic substrate and an inorganic substrate are laminated on each other.

[0364] The thickness of the transparent substrate is preferably 5 μm or more and 500 μm or less, and more preferably 10 μm or more and 100 μm or less.

[0365] Middle layer

[0366] The conductive film of the third embodiment may include an intermediate layer between the transparent substrate and the conductive portion. The intermediate layer can contribute to improving the adhesion between the transparent substrate and the metal thin wires of the conductive portion.

[0367] The components of the intermediate layer are not particularly limited, and examples thereof include silicon compounds such as (poly)silanes, (poly)silazanes, (poly)silothianes, (poly)siloxanes, silicon, silicon carbide, silicon oxide, silicon nitride, silicon chloride, silicate, zeolite, and silicide; aluminum compounds such as aluminum oxide; and magnesium compounds such as magnesium fluoride. Among these, at least one selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride is preferred. The use of such components tends to further improve the transparency and durability of the conductive film, and further enhances productivity (cost reduction) in the production of the conductive film.

[0368] The thickness of the intermediate layer is preferably from 0.01 μm to 500 μm, more preferably from 0.05 μm to 300 μm, and even more preferably from 0.10 μm to 200 μm. By setting the thickness of the intermediate layer to be at least 0.01 μm, adhesion between the intermediate layer and the metal wires is enhanced. If the thickness of the intermediate layer is 500 μm or less, flexibility of the transparent substrate can be ensured.

[0369] By laminating the intermediate layer on the transparent substrate, when the metal component in the ink is sintered by plasma or other sintering means, the transparent substrate in areas not covered by the metal fine line pattern can be prevented from being etched by plasma or other means.

[0370] Furthermore, in order to prevent disconnection of the metal fine wire pattern due to static electricity, the intermediate layer preferably has an antistatic function. In order to impart the antistatic function to the intermediate layer, the intermediate layer preferably contains at least one of a conductive inorganic oxide and a conductive organic compound.

[0371] The volume resistivity of the intermediate layer is preferably 100 Ωcm to 100,000 Ωcm, more preferably 1,000 Ωcm to 10,000 Ωcm, and even more preferably 2,000 Ωcm to 8,000 Ωcm. By setting the volume resistivity of the intermediate layer to 100,000 Ωcm or less, an antistatic function can be exhibited. Furthermore, by setting the volume resistivity of the intermediate layer to 100 Ωcm or greater, the intermediate layer can be suitably used in applications such as touch panels where high conductivity between metal fine line patterns is not preferred.

[0372] The volume resistivity can be adjusted by the content of the conductive inorganic oxide, conductive organic compound, etc. in the intermediate layer. For example, the intermediate layer contains silicon oxide (volume resistivity of 10 14 When using an organosilane compound as a conductive organic compound (e.g., a 100 Ω·cm or greater) and increasing the organosilane compound content, the volume resistivity can be reduced. On the other hand, increasing the silicon oxide content increases the volume resistivity, but due to its high plasma resistance, it can be formed into a thin film without compromising optical properties.

[0373] [Third embodiment: Method for producing a conductive thin film]

[0374] The method for producing the conductive film of the third embodiment is not particularly limited. Examples include a method comprising: a patterning step of forming a pattern on a transparent substrate using an ink containing a metal component; and a firing step of firing the pattern to form fine metal wires. Furthermore, the method for producing the conductive film of the third embodiment may include an intermediate layer forming step of forming an intermediate layer on the surface of the transparent substrate prior to the patterning step.

[0375] [Intermediate layer formation process]

[0376] The intermediate layer forming step is a step of forming an intermediate layer on the surface of a transparent substrate. The method for forming the intermediate layer is not particularly limited, and examples thereof include methods of forming a vapor-deposited film on the surface of a transparent substrate using vapor-phase film-forming methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD); and methods of forming a coating film by coating an intermediate layer-forming composition on the surface of a transparent substrate and drying the composition.

[0377] The composition for forming the intermediate layer contains the components exemplified as the components contained in the intermediate layer or their precursors, and contains a solvent, and may contain a surfactant, a dispersant, a binder, and the like as needed.

[0378] [Pattern Formation Process]

[0379] The pattern forming process is a process for forming a pattern using ink containing a metal component. The pattern forming process is not particularly limited as long as it involves a plate-based printing method using a plate with grooves having the desired metal fine line pattern. It may include the following steps: applying ink to the surface of a transfer medium; placing the ink-coated transfer medium surface opposite to the raised surface of a relief plate, pressing and contacting the surface to transfer the ink on the transfer medium surface to the raised surface of the relief plate; and placing the ink-coated transfer medium surface opposite to the surface of a transparent substrate, pressing and contacting the surface to transfer the ink remaining on the transfer medium surface to the surface of the transparent substrate. Note that if the transparent substrate has an intermediate layer, the ink is transferred to the surface of the intermediate layer.

[0380] (Ink)

[0381] The ink used in the pattern forming step comprises a solvent and a metal component containing conductive metal atoms M, and may also contain a surfactant, a dispersant, a reducing agent, etc. as needed. The metal component may be contained in the ink in the form of metal particles or in the form of a metal complex.

[0382] When metal particles are used, the average primary particle size is preferably less than 100 nm, more preferably less than 50 nm, and further preferably less than 30 nm. In addition, the lower limit of the average primary particle size of the metal particles is not particularly limited, and more than 1 nm can be listed. By making the average primary particle size of the metal particles less than 100 nm, the line width W of the obtained metal fine wire can be further narrowed. It should be noted that, in the third embodiment, the "average primary particle size" refers to the particle size of one metal particle (so-called primary particle), and is distinguished from the particle size of the aggregate (so-called secondary particle) formed by the aggregation of multiple metal particles, that is, the average secondary particle size.

[0383] The metal particles may be in the form of metal oxides such as copper oxide, metal compounds, or core / shell particles having a copper core and a copper oxide shell, as long as they contain conductive metal atoms M. The form of the metal particles can be appropriately determined from the perspectives of dispersibility and sinterability.

[0384] The surfactant is not particularly limited, and examples thereof include silicone surfactants and fluorine-based surfactants. The use of such surfactants tends to improve the ink's applicability to the transfer medium (blanket) and the smoothness of the applied ink, resulting in a more uniform coating. It should be noted that the surfactant is preferably configured to disperse the metal component and to minimize residue residue during firing.

[0385] The dispersant is not particularly limited, and examples thereof include dispersants that non-covalently bond or interact with the metal component and dispersants that covalently bond with the metal component. Examples include dispersants having a phosphate group as a functional group that non-covalently bonds or interacts. The use of such dispersants tends to further improve the dispersibility of the metal component.

[0386] Furthermore, examples of solvents include alcohol solvents such as monohydric alcohols and polyhydric alcohols; alkyl ether solvents; hydrocarbon solvents; ketone solvents; ester solvents, etc. These can be used alone or in combination of one or more. Examples include the combined use of monohydric alcohols having less than 10 carbon atoms and polyhydric alcohols having less than 10 carbon atoms. By using such solvents, there is a tendency to further improve the coating properties of the ink on the transfer medium (blanket), the transfer properties of the ink from the transfer medium to the relief plate, the transfer properties of the ink from the transfer medium to the transparent substrate, and the dispersibility of the metal component. It should be noted that the solvent is preferably constructed in a manner that can disperse the metal component and is not likely to remain after firing.

[0387] It should be noted that the content of the above components contained in the ink can be adjusted from the perspective of adjusting the carbon atoms C and oxygen atoms O in the metal thin wire. For example, by increasing the content of the above components or using a large amount of organic substances containing carbon atoms C and oxygen atoms O as the above components, the carbon atoms C and oxygen atoms O can be increased.

[0388] 〔Firing process〕

[0389] The firing process is a process of firing a pattern to form metal fine wires, thereby obtaining a conductive portion having a metal fine wire pattern identical to the pattern obtained by applying the ink. Firing is not particularly limited as long as it is a method in which the metal components are welded to form a sintered film of the metal component. Firing can be carried out in, for example, a firing furnace, or can be carried out using plasma, a heating catalyst, ultraviolet rays, vacuum ultraviolet rays, electron beams, infrared lamp annealing, flash lamp annealing, laser, etc. When the obtained sintered film is easily oxidized, it is preferably fired in a non-oxidizing atmosphere. In addition, when metal oxides and the like are difficult to be reduced using only a reducing agent that can be contained in the ink, it is preferably fired in a reducing atmosphere.

[0390] A non-oxidizing atmosphere refers to an atmosphere that does not contain oxidizing gases such as oxygen, and there are inert atmospheres and reducing atmospheres. Inert atmospheres refer to atmospheres that are filled with inert gases such as argon, helium, neon, and nitrogen. In addition, reducing atmospheres refer to atmospheres in which reducing gases such as hydrogen and carbon monoxide are present. These gases can be filled into a firing furnace, and the coating film (dispersion coating film) of the ink can be fired in the form of a closed system. In addition, the firing furnace can also be made into a circulation system, and the coating film can be fired while circulating these gases. When the coating film is fired in a non-oxidizing atmosphere, it is preferred that the firing furnace be temporarily vacuumed to remove the oxygen in the firing furnace, and replaced with a non-oxidizing gas. In addition, firing can be carried out in a pressurized atmosphere or in a reduced pressure atmosphere.

[0391] From the perspective of adjusting the proportion of oxygen atoms O contained in the interface of the metal wire by reducing the oxygen atoms O contained in the metal wire, it is possible to consider using a reducing atmosphere for firing. Conversely, from the perspective of adjusting the proportion of oxygen atoms O contained in the interface of the metal wire by increasing the oxygen atoms O contained in the metal wire, it is possible to consider using a weak reducing atmosphere or an inactive atmosphere for firing.

[0392] The firing temperature is not particularly limited, but is preferably 20°C or higher and 400°C or lower, more preferably 50°C or higher and 300°C or lower, further preferably 80°C or higher and 200°C or lower, and particularly preferably 90°C or higher and 130°C or lower. Setting the firing temperature to 400°C or lower allows the use of substrates with low heat resistance, which is preferred. Setting the firing temperature to 20°C or higher allows for the formation of a sintered film to be fully performed, resulting in a tendency for the conductivity to improve, which is preferred. It should be noted that the resulting sintered film contains a conductive component derived from the metal component, and in addition, may contain a non-conductive component depending on the components used in the ink and the firing temperature.

[0393] In addition, firing time is not particularly limited, is preferably more than 15 minutes and below 90 minutes, more preferably more than 20 minutes and below 80 minutes, further preferably more than 30 minutes and below 70 minutes.Be below 90 minutes by making firing time, can use the substrate with low thermotolerance, so preferably.In addition, be more than 15 minutes by making firing temperature, there is the formation that fully carries out sintered film, the good tendency that conductivity becomes, so preferably.

[0394] From the perspective of adjusting the proportion of carbon atoms C contained in the interface of the metal wire by reducing the carbon atoms C contained in the metal wire, it is possible to consider firing at a higher temperature for a long time. Conversely, from the perspective of adjusting the proportion of carbon atoms C contained in the interface of the metal wire by increasing the carbon atoms C contained in the metal wire, it is possible to consider firing at a lower temperature for a short time.

[0395] Among them, from the viewpoint of adjusting the carbon atoms C in the metal thin wires, heat, plasma, electron beams, and light sources are preferably used as energy during firing. It should be noted that these firing methods can be arbitrarily combined to perform multiple firings as needed.

[0396] According to the third embodiment of the present invention, a conductive film having both high conductivity and high adhesion between a transparent substrate and metal thin wires, and electronic paper, a touch panel, and a flat panel display using the conductive film can be provided.

[0397] Conductive film roll

[0398] The conductive film rolls of the first to third embodiments are formed by winding the conductive films of the first to third embodiments described above. The conductive film rolls may have a core at the center for winding the conductive film. The conductive film rolls of the first to third embodiments can be cut to an appropriate size for use in accordance with the intended application (e.g., electronic paper, touch panels, flat panel displays, etc.).

[0399] Electronic paper

[0400] The electronic paper according to the first to third embodiments is not particularly limited as long as it includes the above-described conductive thin film. Figure 8 A plan view showing one embodiment of electronic paper including the conductive film (mesh pattern) according to the first to third embodiments is shown. Figure 9 Partial cross-sectional views taken along the line V-V' of electronic paper according to the first to third embodiments are shown. Figure 10 Shown to indicate that Figure 8 A plan view of one embodiment of electronic paper having a conventional conductive film with a uniform aperture ratio and wide metal thin wire width.

[0401] like Figure 8 As shown in FIG. 1 , the electronic paper 20 is configured such that a metal fine line pattern 12 is arranged on a cup 21 and an electric field can be applied to the cup 21. Specifically, Figure 9 As shown, a cup 21 of the electronic paper 20 contains a charged black pigment 22 and a charged white pigment 23 . The behavior of the charged black pigment 22 and the charged white pigment 23 is controlled by the electric field between the bottom electrode 24 and the conductive film 10 .

[0402] At this time, if Figure 8 and Figure 10 As shown in the comparison, even with the same aperture ratio, when the metal wire pattern is thinner, more metal wires 14 cross directly above the cup 21, allowing the cup 21 to uniformly apply an electric field. Therefore, the electronic paper 20 including the conductive film 10 of the first to third embodiments can provide a higher-resolution image. It should be noted that the configuration of the electronic paper 20 of this embodiment is not limited to that described above.

[0403] Touch panel

[0404] The touch panels of the first to third embodiments are not particularly limited as long as they include the above-described conductive thin film. Figure 11 A perspective view showing one embodiment of a touch panel including the conductive film (line pattern) of the first to third embodiments is shown. In a capacitive touch panel 30, two conductive films 10 are located on the front and back surfaces of an insulator 31, facing each other with their line patterns intersecting. Furthermore, the conductive film 10 may include an extraction electrode 32. The extraction electrode 32 connects the fine metal wires 14 to a controller 33 (such as a CPU) that switches the power flow to the fine metal wires 14.

[0405] also, Figure 12 A perspective view is shown of another embodiment of a touch panel including the conductive films (line patterns) of the first to third embodiments. This touch panel 30 includes metal fine line patterns 12 on both surfaces of the conductive film 10 of the first to third embodiments, instead of having two conductive films 10 on the front and back surfaces of an insulator 31. Thus, two metal fine line patterns 12 are provided on the front and back surfaces of the insulator 31 (transparent substrate 11).

[0406] It should be noted that the touch panels of the first to third embodiments are not limited to the capacitive type, and may be of a resistive film type, a projected capacitive type, a surface capacitive type, or the like.

[0407] Flat panel display

[0408] The flat panel displays according to the first to third embodiments are not particularly limited as long as they include the above-described conductive thin film.

[0409] Example

[0410] Hereinafter, although an Example and a comparative example are shown and embodiment of this invention is demonstrated concretely, this invention is not limited to the following Example and comparative example at all.

[0411] <<Example A>>

[0412] Hereinafter, Example A and Comparative Example A related to the first embodiment will be described in detail.

[0413] 《Transparent Substrate A》

[0414] [Preparation of Transparent Substrate A1]

[0415] A polyethylene terephthalate (PET) transparent substrate was used as a substrate. An interlayer-forming composition containing silicon oxide nanoparticles and a conductive organosilane compound was applied thereto and dried to form an antistatic interlayer containing silicon oxide having a thickness of 150 nm and a volume resistivity of 5000 Ωcm. Transparent substrate A1 was obtained. It should be noted that transparent substrate A1 is a structure in which an interlayer is laminated on a transparent PET substrate.

[0416] [Preparation of Transparent Substrate A2]

[0417] The PET used to prepare the transparent substrate A1 was used as the transparent substrate A2.

[0418] Ink A

[0419] [Ink A1]

[0420] Ink A1 in which copper oxide nanoparticles are dispersed was prepared by mixing 20 parts by mass of copper oxide nanoparticles (copper oxide fine particles manufactured by CIK NANOTEC), 4 parts by mass of a dispersant (manufactured by BYKCHEMIE, product name: Disperbyk-145), 1 part by mass of a surfactant (manufactured by SEIMI CHEMICAL, product name: S-611), and 75 parts by mass of an organic solvent (n-butanol and 2-propylene glycol).

[0421] [Ink A2]

[0422] 20 parts by mass of cuprous oxide nanoparticles with a particle size of 21 nm, 4 parts by mass of a dispersant (product name: Disperbyk-145, manufactured by BYK CHEMIE), 1 part by mass of a surfactant (product name: S-611, manufactured by SEIMI CHEMICAL), and 75 parts by mass of ethanol were mixed to prepare ink A2 having a cuprous oxide nanoparticle content of 20% by mass.

[0423] [Ink A3]

[0424] Ink A3 was prepared by adding 5.0 parts by mass of organopolysiloxane to 100 parts by mass of ink A1.

[0425] <Example A1>

[0426] Manufacturing of Conductive Thin Films

[0427] First, ink A1 was applied to the surface of a transfer medium. The transfer medium surface coated with ink A1 was then placed against a plate with a grooved metal line pattern and pressed into contact, transferring a portion of the ink A1 from the transfer medium surface to the plate's raised surface. Subsequently, the transfer medium surface with the remaining ink A1 applied was placed against a transparent substrate A1 and pressed into contact, transferring the desired metal line pattern of ink A1 onto the transparent substrate A1. The metal line pattern of ink A1 (dispersion coating film) was then flash-lamped and fired at room temperature using a Pulseforge 1300 manufactured by Nova Centrix, resulting in a conductive thin film containing a grid pattern of metal lines with the line widths and thicknesses shown in Table 1.

[0428] 《Evaluation of Conductive Thin Films》

[0429] [Example A: Sheet Resistance]

[0430] The sheet resistance R of the obtained conductive film was measured by the following method. s0 (Ω / sq). First, a 100 mm square measurement sample was cut out from the portion of the conductive film where the metal fine line pattern was arranged. Then, a silver paste was applied to both ends of the surface of the obtained measurement sample in the width direction using a screen printing device and dried. Figure 13 A long current collector of 10 mm in width and 100 mm in depth was formed as shown. The resistance R (Ω) at both ends of the sample was measured by the two-terminal method, with the measuring terminals of an ohmmeter in contact. The sheet resistance R was calculated from the obtained resistance using the following formula: s0(Ω / sq). The results are shown in Table 1 below. It should be noted that the sheet resistance of a conductive film having a protective layer on its surface was measured by producing a conductive film in which the current collecting portion of a metal fine line pattern was exposed, while the remaining metal fine line patterns were covered by the protective layer. Specifically, the current collecting portion formed using the above method was masked, a protective layer was formed, and finally the mask was removed to produce a conductive film in which only the current collecting portion was exposed.

[0431] R s0 =R / L×D

[0432] L: 80 (mm): Distance between current collectors

[0433] D: 100 (mm): distance in the depth direction

[0434] [Example A: Visible Light Transmittance and Haze]

[0435] The visible light transmittance of the conductive film was measured by calculating the transmittance of visible light with a wavelength of 360 to 830 nm according to the total light transmittance of JIS K 7361-1:1997. Furthermore, the haze of the conductive film was measured according to JIS K 7136:2000. The results are shown in Table 1 below.

[0436] [Example A: STEM-EDX Analysis of a Metal Thin Wire Cross Section]

[0437] The resulting conductive film was embedded in an epoxy resin support and sliced using an ultramicrotome along the surface of the metal wires perpendicular to their extension direction, yielding 80 nm thick thin sections. The resulting thin sections served as measurement samples and were subjected to STEM-EDX analysis using electron beam irradiation under the following conditions.

[0438] STEM: Hitachi High-Technologies, Inc., scanning transmission electron microscope HD-2300A

[0439] EDX: EDAX, energy dispersive X-ray analyzer, GENESIS

[0440] Accelerating voltage: 200 kV

[0441] Measurement magnification: 25,000 times

[0442] Electron beam incident angle: 90°

[0443] X-ray extraction angle: 18°

[0444] Mapping elements: Cu, Ag, Si

[0445] Cumulative times: 200 times

[0446] dwell time: 200μsec.

[0447] Resolution: 256 × 200 pixels

[0448] First, the maximum thickness T from the metal wire interface on the transparent substrate side to the metal wire surface is calculated based on the STEM image of the cross section of the metal wire obtained by STEM. Next, the atomic % of Si atoms is calculated from the cumulative value of the EDX intensity of the K layer of silicon atoms Si in the thickness region of 0.10T to 0.90T from the metal wire interface on the transparent substrate side. The atomic % of M atoms is calculated from the cumulative value of the EDX intensity of the K layer of conductive metal atoms M other than silicon in the thickness region of 0.10T to 0.90T from the metal wire interface on the transparent substrate side, thereby calculating Si / M 0.10～0.90 Next, the atomic percentage of Si atoms is calculated from the cumulative value of the EDX intensity of the K layer of silicon atoms Si in the thickness region of 0.10T to 0.25T from the metal fine line interface on the transparent substrate side. The atomic percentage of M atoms is calculated from the cumulative value of the EDX intensity of the K layer of conductive metal atoms M other than silicon in the thickness region of 0.10T to 0.25T from the metal fine line interface on the transparent substrate side. Thus, Si / M 0.10～0.25 Next, the atomic percentage of Si atoms is calculated from the cumulative value of the EDX intensity of the K layer of silicon atoms Si in the thickness region of 0.75T to 0.90T from the metal fine line interface on the transparent substrate side. The atomic percentage of M atoms is calculated from the cumulative value of the EDX intensity of the K layer of conductive metal atoms M other than silicon in the thickness region of 0.75T to 0.90T from the metal fine line interface on the transparent substrate side. Thus, Si / M 0.75～0.90 .

[0449] [Example A: Flexibility]

[0450] To evaluate the flexibility of the conductive film, the sheet resistance change (%) was measured before and after a repeated bending test. The repeated bending test was conducted using a conductive film for measuring sheet resistance using an Imoto Seisakusho (IMC-1304) bending tester, according to JIS C 5016:1994, under the following conditions. It should be noted that a lack of flexibility leads to a greater change in sheet resistance due to, for example, breakage of the metal wires, while excellent flexibility results in a smaller change in sheet resistance.

[0451] Bending radius: 5mm

[0452] Test stroke: 20mm

[0453] Bending speed: 90rpm

[0454] Bending times: 10,000 times

[0455] Next, the sheet resistance R of the conductive film after the repeated bending test was measured. s1 (Ω / sq), and the sheet resistance change rate was calculated using the following formula.

[0456] (Sheet resistance change rate) = R s1 / R s0 ×100

[0457] <Example A2>

[0458] Using a plate having grooves with a metal fine line pattern and a transfer medium impregnated with the inks and liquid organopolysiloxane listed in Table 1, a dispersion coating film with a grid pattern was formed on a transparent substrate of the types listed in Table 1. The dispersion coating film was then fired at room temperature using a Nova Centrix Pulseforge 1300 by flash lamp annealing to produce a conductive film comprising metal fine lines in a grid pattern with the line widths and thicknesses listed in Table 1. Various properties of the resulting conductive film are shown in Table 1.

[0459] <Example A3>

[0460] A conductive film comprising fine metal lines having a grid pattern with the line widths and thicknesses shown in Table 1 was obtained in the same manner as in Example A1, except that Ink A2 was used and plasma annealing was used instead of flash lamp annealing for firing and reduction. Table 1 shows various properties of the resulting conductive film.

[0461] <Examples A4 to A6 and Comparative Examples A1 to A2>

[0462] Using a plate having grooves with a fine metal line pattern and the inks listed in Table 1, a dispersion coating film with a grid pattern was formed on a transparent substrate of the type shown in Table 1. The dispersion coating film was then fired at room temperature using a Pulseforge 1300 manufactured by Nova Centrix, using flash lamp annealing. This yielded a conductive film comprising fine metal lines in a grid pattern with the line widths and thicknesses shown in Table 1. Various properties of the resulting conductive film are shown in Table 1.

[0463] [Table 1]

[0464]

[0465] It can be seen from Examples A1 to A6 and Comparative Examples A1 to A2 that: in the STEM-EDX analysis of the cross-section of the metal wire orthogonal to the extension direction of the metal wire, by making the atomic % ratio Si / M of the aforementioned silicon atoms Si relative to the conductive metal atoms M greater than 0.001 and less than 0.070, a conductive film can be obtained that fully maintains transparency (i.e., low visibility achieved by a small line width) and has excellent conductivity (i.e., low sheet resistance) and flexibility.

[0466] <<Example A'>>

[0467] Hereinafter, Example A' and Comparative Example A' related to the first embodiment will be described in detail.

[0468] 《Transparent Substrate A'》

[0469] [Preparation of Transparent Substrate A'1]

[0470] A 50 nm thick interlayer containing silicon oxide was formed on a polyethylene terephthalate (PET) transparent substrate by sputtering to obtain a transparent substrate A'1. It should be noted that the transparent substrate A'1 is a PET transparent substrate with an interlayer laminated thereon.

[0471] [Preparation of Transparent Substrate A'2]

[0472] A transparent substrate A'2 was obtained by coating a composition for forming an intermediate layer containing dispersed silicon oxide nanoparticles on a PET transparent substrate and drying the composition. This composition formed an intermediate layer containing silicon oxide having an antistatic function, a thickness of 150 nm, and a volume resistivity of 5000 Ωcm. It should be noted that transparent substrate A'2 was a structure in which an intermediate layer was laminated on a transparent PET substrate.

[0473] [Preparation of Transparent Substrate A'3]

[0474] Transparent substrate A'3 with an intermediate layer was prepared in the same manner as transparent substrate A'2, except that polyethylene naphthalate (PEN) was used instead of PET as the organic substrate. It should be noted that transparent substrate A'3 has an intermediate layer laminated on PEN as the transparent substrate.

[0475] [Preparation of Transparent Substrate A'4]

[0476] The PET used to prepare the transparent substrate A'1 was used as the transparent substrate A'4.

[0477] Ink A'

[0478] [Ink A'1]

[0479] 20 parts by mass of copper oxide nanoparticles (copper oxide fine particles manufactured by CIK NANOTEC), 4 parts by mass of a dispersant (manufactured by BYKCHEMIE, product name: Disperbyk-145), 1 part by mass of a surfactant (manufactured by SEIMI CHEMICAL, product name: S-611), and 75 parts by mass of an organic solvent (n-butanol and 2-propylene glycol) were mixed to prepare ink A'1 in which copper oxide nanoparticles were dispersed.

[0480] [Ink A'2]

[0481] To 100 parts by mass of silver nano-ink (RAGT-29) manufactured by DIC Corporation, 50 parts by mass of ethanol was added to prepare ink A'2.

[0482] <Example A'1>

[0483] Manufacturing of Conductive Thin Films

[0484] First, ink A'1 is applied to the surface of a transfer medium. Next, the transfer medium surface coated with ink A'1 is placed opposite a plate having grooves with a metal fine line pattern, and pressed and brought into contact with the plate, thereby transferring a portion of the ink A'1 on the transfer medium surface to the raised surface of the plate. Subsequently, the transfer medium surface coated with the remaining ink A'1 is placed opposite a transparent substrate A'1, and pressed and brought into contact with the plate, thereby transferring the desired metal fine line pattern of ink A'1 onto the transparent substrate A'1. Next, the metal fine line pattern of ink A'1 (dispersion coating film) is fired at room temperature using a Pulseforge 1300 manufactured by NovaCentrix by flash lamp annealing to obtain a conductive film comprising a grid pattern of metal fine lines with the line widths shown in Table 2.

[0485] 《Evaluation of Conductive Thin Films》

[0486] The sheet resistance, visible light transmittance, haze, STEM-EDX analysis of the metal thin wire cross section, and flexibility measurement of Example A' were performed using the same methods as those described in Example A.

[0487] <Examples A'2, A'4 to A'7 and Comparative Examples A'1 and A'2>

[0488] Using a plate having grooves with a fine metal line pattern and the inks listed in Table 2, a dispersion coating film with a grid pattern was formed on a transparent substrate of the types shown in Table 2. The dispersion coating film was then fired at room temperature using a Pulseforge 1300 manufactured by Nova Centrix, using flash lamp annealing. This yielded a conductive film comprising fine metal lines in a grid pattern with the line widths shown in Table 2. Various properties of the resulting conductive film are shown in Table 2.

[0489] <Example A'3>

[0490] Using a plate having grooves with a metal fine line pattern and a transfer medium impregnated with the inks and liquid organopolysiloxane listed in Table 2, a dispersion coating film with a grid pattern was formed on a transparent substrate of the types listed in Table 2. The dispersion coating film was then flash-lamped and fired at room temperature using a Pulseforge 1300 manufactured by Nova Centrix, resulting in a conductive film comprising metal fine lines in a grid pattern with the line widths listed in Table 2. Various properties of the resulting conductive film are shown in Table 2.

[0491] [Table 2]

[0492]

[0493] It can be seen from Examples A'1 to A'7 and Comparative Examples A'1 to A'2 that: in the STEM-EDX analysis of the cross-section of the metal wire orthogonal to the extension direction of the metal wire, by making the atomic % ratio Si / M of the aforementioned silicon atoms Si relative to the conductive metal atoms M greater than 0.001 and less than 0.070, a conductive film can be obtained that fully maintains transparency (i.e., low visibility achieved by a small line width) and has excellent conductivity (i.e., low sheet resistance) and flexibility.

[0494] <<Example B>>

[0495] Hereinafter, Example B and Comparative Example B related to the second embodiment will be described in detail.

[0496] Transparent Substrate B

[0497] [Preparation of transparent substrate B1]

[0498] Polyethylene terephthalate (PET) was used as a transparent substrate, and an intermediate layer-forming composition containing silicon oxide nanoparticles and a conductive organosilane compound was coated thereon and dried to form an intermediate layer containing silicon oxide with an antistatic function, a thickness of 150 nm, and a volume resistivity of 5000 Ωcm, thereby obtaining a transparent substrate B1.

[0499] Ink B

[0500] [Ink B1]

[0501] Ink B1 in which copper oxide nanoparticles are dispersed was prepared by mixing 20 parts by mass of copper oxide nanoparticles (copper oxide microparticles manufactured by CIK NANOTEC), 4 parts by mass of a dispersant (manufactured by BYKCHEMIE, product name: Disperbyk-145), 1 part by mass of a surfactant (manufactured by SEIMI CHEMICAL, product name: S-611), and 75 parts by mass of an organic solvent (n-butanol and 2-propylene glycol).

[0502] [Ink B2]

[0503] 20 parts by mass of commercially available silver oxide nanoparticles, 5 parts by mass of a dispersant (hydroxypropyl cellulose), and 75 parts by mass of an organic solvent (sec-butanol) were mixed to prepare ink B2 in which silver oxide nanoparticles were dispersed.

[0504] <Example B1>

[0505] Manufacturing of Conductive Thin Films

[0506] First, ink B1 is applied to the surface of a transfer medium. The transfer medium surface coated with ink B1 is then placed against a plate with a grooved metal line pattern and pressed into contact, transferring a portion of the ink B1 from the transfer medium surface to the plate's raised surfaces. The transfer medium surface, still coated with the remaining ink B1, is then placed against a transparent substrate B1 and pressed into contact, transferring the desired pattern of ink B1 to the transparent substrate B1. The ink B1 pattern is then fired in a commercially available infrared oven under the following conditions to promote the reduction of copper oxide on the surface of the metal lines. This results in a conductive film with a 1μm-wide grid pattern of metal lines, in which oxygen atoms (O) are predominantly present at the interface with the transparent substrate B1.

[0507] Heat source: infrared lamp

[0508] Irradiation temperature: 180°C

[0509] Irradiation time: 220 minutes

[0510] Environment: Nitrogen atmosphere containing hydrogen

[0511] 《Evaluation of Conductive Thin Films》

[0512] [Example B: Sheet Resistance]

[0513] The sheet resistance R of the obtained conductive film was measured by the following method. s0(Ω / sq). First, a 100 mm square measurement sample was cut out from the portion of the conductive film where the metal fine line pattern was arranged. Then, a silver paste was applied to both ends of the surface of the obtained measurement sample in the width direction using a screen printing device and dried. Figure 13 A long current collecting section with a width of 10 mm and a depth of 100 mm was formed as shown. Next, the resistance R (Ω) between the current collecting sections at both ends of the sample was measured by the two-terminal method of contacting the measuring terminals of an ohmmeter. The sheet resistance R was calculated from the obtained resistance using the following formula: s0 (Ω / sq). It should be noted that the sheet resistance of a conductive film with a protective layer on its surface was measured by producing a conductive film in which the current collecting portion of a metal fine line pattern was exposed, while the remaining metal fine line patterns were covered by the protective layer. Specifically, the current collecting portion formed using the above method was masked, a protective layer was formed, and finally the mask was removed to produce a conductive film in which only the current collecting portion was exposed. The results are shown in Table 3 below.

[0514] R s0 =R / L×D

[0515] L: 80 (mm): Distance between current collectors

[0516] D: 100 (mm): distance in the depth direction

[0517] [Example B: Visible Light Transmittance and Haze]

[0518] The visible light transmittance of the conductive film was measured by calculating the transmittance of visible light with a wavelength of 360 to 830 nm according to the total light transmittance of JIS K 7361-1:1997. Furthermore, the haze of the conductive film was measured according to JIS K 7136:2000. The results are shown in Table 3 below.

[0519] [Example B: STEM-EDX Analysis of Metal Thin Wire Cross Section]

[0520] The resulting conductive film was embedded in an epoxy resin support and sliced using an ultramicrotome along a plane perpendicular to the direction in which the metal wires extended, yielding 80 nm thick thin sections. The resulting thin sections served as measurement samples and were subjected to STEM-EDX analysis using electron beam irradiation under the following conditions.

[0521] STEM: Hitachi High-Technologies, Inc., scanning transmission electron microscope HD-2300A

[0522] EDX: EDAX, energy dispersive X-ray analyzer, GENESIS

[0523] Accelerating voltage: 200 kV

[0524] Measurement magnification: 25,000 times

[0525] Electron beam incident angle: 90°

[0526] X-ray extraction angle: 18°

[0527] Mapping elements: Cu, Ag, O

[0528] Cumulative times: 200 times

[0529] dwell time: 200μsec.

[0530] Resolution: 256 × 200 pixels

[0531] The sample obtained by the above operation was observed using STEM to obtain a STEM image of the cross section of the metal wire. Simultaneously, elemental mapping of the cross section of the metal wire was performed using energy dispersive X-ray analysis (EDX). Specifically, the EDX intensity of the K layer of the oxygen atoms O and the EDX intensity of the K layer of the conductive metal atoms M were measured at each location in the cross section, and this operation was repeated for the entire cross section of the metal wire.

[0532] On the other hand, the maximum thickness T from the metal wire interface on the transparent substrate side to the metal wire surface is calculated based on the STEM image. The cumulative value of the EDX intensity of the K layer of the oxygen atoms O and the cumulative value of the EDX intensity of the K layer of the conductive metal atoms M in the thickness region of 0.10T to 0.90T from the metal wire interface on the transparent substrate side are calculated, and the ratio of these cumulative values is obtained as the atomic % ratio O / M 0.10～0.90 In addition, for the atomic % ratio O / M 0.75～0.90 , atomic % ratio O / M 0.10～0.25 , in the thickness area as the object, the same method is used to calculate.

[0533] <Examples B2 to B10 and Comparative Examples B1 to B3>

[0534] Conductive thin films were prepared and evaluated in the same manner as in Example B1 except that the transparent substrate, ink, line width, firing conditions, etc. were changed as shown in Table 3. The results are shown in Table 3 below.

[0535] [Table 3]

[0536]

[0537] It can be seen from Examples B1 to B10 and Comparative Examples B1 to B3 that: in the STEM-EDX analysis of the cross-section of the metal wire orthogonal to the extension direction of the metal wire, by adjusting the atomic % ratio O / M of the conductive metal atoms M and the oxygen atoms O to the range of 0.01 to 1.00, a conductive film having both high transparency (i.e., small line width, high transmittance and low haze) and high conductivity can be obtained.

[0538] <<Example B'>>

[0539] Hereinafter, Example B' and Comparative Example B' related to the second embodiment will be described in detail.

[0540] Transparent Substrate B'

[0541] [Preparation of Transparent Substrate B'1]

[0542] A transparent substrate B'1 was obtained by coating a composition for forming an intermediate layer containing dispersed silicon oxide nanoparticles on a polyethylene terephthalate (PET) transparent substrate and drying the composition to form an intermediate layer containing silicon oxide with a thickness of 150 nm and a volume resistivity of 5000 Ωcm.

[0543] Ink B'

[0544] [Ink B'1]

[0545] 20 parts by mass of copper oxide nanoparticles (copper oxide fine particles manufactured by CIK NANOTEC), 4 parts by mass of a dispersant (manufactured by BYKCHEMIE, product name: Disperbyk-145), 1 part by mass of a surfactant (manufactured by SEIMI CHEMICAL, product name: S-611), and 75 parts by mass of an organic solvent (n-butanol and 2-propylene glycol) were mixed to prepare ink B'1 in which copper oxide nanoparticles were dispersed.

[0546] [Ink B'2]

[0547] 20 parts by mass of commercially available silver oxide nanoparticles, 5 parts by mass of a dispersant (hydroxypropyl cellulose), and 75 parts by mass of an organic solvent (sec-butyl alcohol) were mixed to prepare ink B'2 in which silver oxide nanoparticles were dispersed.

[0548] <Example B'1>

[0549] Manufacturing of Conductive Thin Films

[0550] First, ink B'1 is applied to the surface of a transfer medium. Next, the transfer medium surface coated with ink B'1 is placed against a plate with grooves having a fine metal line pattern, pressed and brought into contact, causing a portion of the ink B'1 on the transfer medium surface to transfer to the raised surface of the plate. Subsequently, the transfer medium surface coated with the remaining ink B'1 is placed against a transparent substrate B'1 and pressed and brought into contact, transferring the desired fine metal line pattern of ink B'1 onto the transparent substrate B'1. Next, the pattern of ink B'1 is fired in a commercially available infrared oven under the following conditions to promote the reduction of copper oxide on the surface side of the fine metal lines. This results in a conductive film having a grid pattern of fine metal lines with a line width of 1 μm and a predominant presence of oxygen atoms O at the interface with the transparent substrate B'1.

[0551] Heat source: infrared lamp

[0552] Irradiation temperature: 180°C

[0553] Irradiation time: 220 minutes

[0554] Environment: Nitrogen atmosphere containing hydrogen

[0555] 《Evaluation of Conductive Thin Films》

[0556] The sheet resistance, visible light transmittance, haze, and STEM-EDX analysis of the metal thin wire cross section of Example B' were measured by the same method as described in Example B.

[0557] <Examples B'2 to B'10 and Comparative Examples B'1 to B'2>

[0558] Conductive thin films were prepared and evaluated in the same manner as in Example B'1 except that the transparent substrate, ink, line width, firing conditions, etc. were changed as shown in Table 4. The results are shown in Table 4 below.

[0559] [Table 4]

[0560]

[0561] It can be seen from Examples B'1 to B'10 and Comparative Examples B'1 to B'2 that: in the STEM-EDX analysis of the cross-section of the metal wire orthogonal to the extension direction of the metal wire, by adjusting the atomic % ratio O / M of the conductive metal atoms M and the oxygen atoms O to the range of 0.01 to 1.00, a conductive film having both high transparency (i.e., small line width, high transmittance and low haze) and high conductivity can be obtained.

[0562] <<Example C>>

[0563] Hereinafter, Example C and Comparative Example C related to the third embodiment will be described in detail.

[0564] Transparent Substrate C

[0565] [Preparation of transparent substrate C1]

[0566] Polyethylene terephthalate (PET) was used as a transparent substrate, and an intermediate layer-forming composition containing silicon oxide nanoparticles and a conductive organosilane compound was coated thereon and dried to form an intermediate layer containing silicon oxide having an antistatic function, a thickness of 150 nm, and a volume resistivity of 5000 Ωcm, thereby obtaining transparent substrate C1.

[0567] [Preparation of transparent substrate C2]

[0568] A transparent substrate C2 was obtained by the same method as the method for preparing the transparent substrate C1, except that polyethylene naphthalate (PEN) was used as the transparent substrate instead of PET.

[0569] Ink C

[0570] [Ink C1]

[0571] 20 parts by mass of copper oxide nanoparticles (copper oxide fine particles manufactured by CIK NANOTEC), 4 parts by mass of a dispersant (manufactured by BYKCHEMIE, product name: Disperbyk-145), 1 part by mass of a surfactant (manufactured by SEIMI CHEMICAL, product name: S-611), and 75 parts by mass of an organic solvent (n-butanol and 2-propylene glycol) were mixed to prepare ink C1 in which copper oxide nanoparticles were dispersed.

[0572] [Ink C2]

[0573] To 100 parts by mass of silver nano-ink (RAGT-29) manufactured by DIC Corporation, 50 parts by mass of ethanol was added to prepare ink C2.

[0574] <Example C1>

[0575] Manufacturing of Conductive Thin Films

[0576] First, ink C1 is applied to the surface of a transfer medium. The transfer medium surface coated with ink C1 is then placed against a plate with a grooved metal line pattern and pressed into contact, transferring some of the ink from the transfer medium surface to the plate's raised surfaces. The transfer medium surface, still coated with the remaining ink C1, is then placed against a transparent substrate C1 and pressed into contact, transferring the desired metal line pattern of ink C1 onto the transparent substrate C1. The ink C1 pattern is then heated and fired in a reducing atmosphere under the following conditions, yielding a conductive thin film with a 1μm-wide mesh pattern of metal lines.

[0577] Environment: Helium-hydrogen atmosphere

[0578] Heating temperature: 100°C

[0579] Heating time: 60 minutes

[0580] 《Evaluation of Conductive Thin Films》

[0581] [Example C: Sheet Resistance]

[0582] The sheet resistance R of the obtained conductive film was measured by the following method. s0 (Ω / sq). First, a 100 mm square measurement sample was cut out from the portion of the conductive film where the metal fine line pattern was arranged. Then, a silver paste was applied to both ends of the surface of the obtained measurement sample in the width direction using a screen printing device and dried. Figure 13 A long current collecting section with a width of 10 mm and a depth of 100 mm was formed as shown. Next, the resistance R (Ω) between the current collecting sections at both ends of the sample was measured by the two-terminal method of contacting the measuring terminals of an ohmmeter. The sheet resistance R was calculated from the obtained resistance using the following formula: s0 (Ω / sq). It should be noted that the sheet resistance of a conductive film with a protective layer on its surface was measured by fabricating a conductive film in which the current collecting portion of a metal fine line pattern was exposed, while the remaining metal fine line patterns were covered by the protective layer. Specifically, the current collecting portion formed using the above method was masked, a protective layer was formed, and finally the mask was removed, thereby fabricating a conductive film in which only the current collecting portion was exposed. The results are shown in Table 5 below.

[0583] R s0 =R / L×D

[0584] L: 80 (mm): Distance between current collectors

[0585] D: 100 (mm): Depth of the measurement sample

[0586] [Example C: Visible Light Transmittance and Haze]

[0587] The visible light transmittance of the conductive film was measured by calculating the transmittance of visible light with a wavelength of 360 to 830 nm according to the total light transmittance of JIS K 7361-1:1997. Furthermore, the haze of the conductive film was measured according to JIS K 7136:2000. The results are shown in Table 5 below.

[0588] [Example C: STEM-EDX Analysis of Metal Thin Wire Cross Section]

[0589] Using a focused ion beam (FIB), the resulting conductive film was sliced into thin sections with a thickness of 200 nm or less, encompassing a cross section perpendicular to the direction of extension of the metal wires. The resulting thin sections were mounted on the tip of a silicon sample stage and used as measurement samples for STEM-EDX measurements under the following conditions.

[0590] STEM: Hitachi High-Technologies, Inc., scanning transmission electron microscope HD-2300A

[0591] EDX: EDAX, energy dispersive X-ray analyzer, GENESIS

[0592] Accelerating voltage: 200 kV

[0593] Measurement magnification: 25,000 times

[0594] Electron beam incident angle: 90°

[0595] X-ray extraction angle: 18°

[0596] Mapping elements: Cu, Ag, C, O

[0597] Cumulative times: 200 times

[0598] dwell time: 200μsec.

[0599] Resolution: 256 × 200 pixels

[0600] Next, the sample obtained by the above operation was observed using STEM to obtain a STEM image of the cross section of the metal wire. Simultaneously, elemental mapping of the cross section of the metal wire was performed using energy dispersive X-ray analysis (EDX). Specifically, the EDX intensity of the K layer of the carbon atoms C and the EDX intensity of the K layer of the conductive metal atoms M were measured at each location in the cross section, and this operation was repeated for the entire cross section of the metal wire.

[0601] On the other hand, the maximum thickness T from the metal wire interface on the transparent substrate side to the metal wire is calculated based on the STEM image. The cumulative value of the EDX intensity of the K layer of carbon atoms C and the cumulative value of the EDX intensity of the K layer of conductive metal atoms M in the thickness region of 0.10T to 0.25T from the metal wire interface on the transparent substrate side are calculated. The ratio of these cumulative values is obtained as the atomic % ratio C / M 0.10～0.25 The atomic % ratio of oxygen atoms O to conductive metal atoms M is O / M 0.10～0.25 , was also calculated by the same method. The results are shown in Table 5 below.

[0602] [Example C: Adhesion]

[0603] The 180° peel test method was used to evaluate the adhesion of the metal wires to the transparent substrate of the obtained conductive film. Specifically, KAPTON Adhesive Tape 650S manufactured by TERAOKA was affixed to the metal wire portion (conductive portion) of the obtained conductive film, and one end was peeled off from the conductive film, and the tape was peeled off while being folded back 180°. The surface of the transparent substrate after the tape was peeled off was observed, and the case where the metal wires remained on the transparent substrate was judged to have good adhesion. It should be noted that the case of good adhesion was recorded as A, and the case where a portion of the metal wires were observed to be peeled off was recorded as B. The results are shown in Table 5 below.

[0604] <Examples C2 to C6 and Comparative Examples C1 to C8>

[0605] A conductive film was produced by the same procedures as in Example C1, except that the transparent substrate, ink, and firing conditions were changed as shown in Table 5. These conditions are shown in Table 5. The results of the evaluation of the produced conductive film are also shown in Table 5.

[0606] [Table 5]

[0607]

[0608] It can be seen from Examples C1 to C6 and Comparative Examples C1 to C8 that by adjusting the atomic % ratio of conductive metal atoms M to carbon atoms C in the cross-section of the metal wire to a specific range, a conductive film can be obtained that maintains high transparency (i.e., small line width) while having high conductivity and high adhesion between the transparent substrate and the metal wire.

[0609] <<Example C'>>

[0610] Hereinafter, Example C' and Comparative Example C' related to the third embodiment will be described in detail.

[0611] Transparent Substrate C'

[0612] [Preparation of Transparent Substrate C'1]

[0613] Polyethylene terephthalate (PET) was used as a transparent substrate, and a silicon oxide layer having a thickness of 50 nm was formed as an intermediate layer on the PET by sputtering to obtain a transparent substrate C'1.

[0614] [Preparation of Transparent Substrate C'2]

[0615] A transparent substrate C'2 was obtained by the same method as the method for preparing the transparent substrate C'1, except that polyethylene naphthalate (PEN) was used as the transparent substrate instead of PET.

[0616] Ink C'

[0617] [Ink C'1]

[0618] Ink C'1 in which copper oxide nanoparticles are dispersed was prepared by mixing 20 parts by mass of copper oxide nanoparticles (copper oxide fine particles manufactured by CIK NANOTEC), 4 parts by mass of a dispersant (product name: Disperbyk-145 manufactured by BYKCHEMIE), 1 part by mass of a surfactant (product name: S-611 manufactured by SEIMI CHEMICAL), and 75 parts by mass of an organic solvent (n-butanol and 2-propylene glycol).

[0619] [Ink C'2]

[0620] To 100 parts by mass of silver nano-ink (RAGT-29) manufactured by DIC Corporation, 50 parts by mass of ethanol was added to prepare ink C'2.

[0621] <Example C'1>

[0622] Manufacturing of Conductive Thin Films

[0623] First, ink C'1 is applied to the surface of a transfer medium. The transfer medium surface coated with ink C'1 is then placed against a plate with a grooved metal line pattern and pressed into contact, transferring some of the ink from the transfer medium surface to the plate's raised surfaces. The transfer medium surface, still coated with the remaining ink C'1, is then placed against a transparent substrate C'1 and pressed into contact, transferring the desired metal line pattern of ink C'1 onto the transparent substrate C'1. The ink C'1 pattern is then heated and fired in a reducing atmosphere under the following conditions, yielding a conductive thin film with a 1μm-wide mesh pattern of metal lines.

[0624] Environment: Helium-hydrogen atmosphere

[0625] Heating temperature: 100°C

[0626] Heating time: 60 minutes

[0627] 《Evaluation of Conductive Thin Films》

[0628] The sheet resistance, visible light transmittance, haze, STEM-EDX analysis of the metal wire cross section, and adhesion measurement of Example C' were performed by the same methods as those described in Example C.

[0629] <Example C'2 and Comparative Examples C'1 to C'4>

[0630] A conductive film was produced by the same procedures as in Example C1, except that the transparent substrate, ink, and firing conditions were modified as shown in Table 6. The conditions are shown in Table 6. The results of the evaluation of the produced conductive film are also shown in Table 6.

[0631] [Table 6]

[0632]

[0633] It can be seen from Examples C'1 to C'2 and Comparative Examples C'1 to C'4 that by adjusting the atomic % ratio of conductive metal atoms M to carbon atoms C in the cross-section of the metal wire to a specific range, a conductive film can be obtained that maintains high transparency (i.e., small line width) while having high conductivity and high adhesion between the transparent substrate and the metal wire.

[0634] <<Example D>>

[0635] Hereinafter, Example D and Comparative Example D related to the second embodiment and the third embodiment will be described in detail.

[0636] Transparent Substrate D

[0637] [Preparation of transparent substrate D1]

[0638] A transparent substrate D1 was obtained by coating a composition for forming an intermediate layer containing silicon oxide nanoparticles and a conductive organosilane compound on a PET transparent substrate and drying the composition. This composition formed an intermediate layer containing silicon oxide having an antistatic function, a thickness of 150 nm, and a volume resistivity of 5000 Ωcm. It should be noted that transparent substrate D1 is a structure in which an intermediate layer is laminated on a transparent PET substrate.

[0639] Ink D

[0640] [Ink D1]

[0641] 20 parts by mass of cuprous oxide nanoparticles having a particle size of 21 nm, 4 parts by mass of a dispersant (product name: Disperbyk-145, manufactured by BYK CHEMIE), 1 part by mass of a surfactant (product name: S-611, manufactured by SEIMI CHEMICAL), and 75 parts by mass of ethanol were mixed to prepare ink D1 having a cuprous oxide nanoparticle content of 20% by mass.

[0642] <Example D1>

[0643] Preparation of Conductive Thin Films

[0644] First, ink D1 was applied to the surface of a transfer medium. The ink-coated surface was then placed against a plate with a grooved metal line pattern and pressed into contact, transferring some of the ink from the transfer medium to the plate's raised surfaces. The remaining ink was then placed against a transparent substrate and pressed into contact, transferring the desired metal line pattern of ink D1 to the transparent substrate. The ink D1 pattern was then reduced using a plasma sintering device under the conditions listed in Table 7, yielding a conductive film with a 1μm-wide mesh pattern of metal lines.

[0645] 《Evaluation of Conductive Thin Films》

[0646] [Example D: Sheet Resistance]

[0647] The sheet resistance R of the obtained conductive film was measured by the following method. s0 (Ω / sq). First, a 100 mm square measurement sample was cut out from the portion of the conductive film where the metal fine line pattern was arranged. Then, a silver paste was applied to both ends of the surface of the obtained measurement sample in the width direction using a screen printing device and dried. Figure 13 A long current collecting section with a width of 10 mm and a depth of 100 mm was formed as shown. Next, the resistance R (Ω) between the current collecting sections at both ends of the sample was measured by the two-terminal method of contacting the measuring terminals of an ohmmeter. The sheet resistance R was calculated from the obtained resistance using the following formula: s0 (Ω / sq). It should be noted that the sheet resistance of a conductive film with a protective layer on its surface was measured by producing a conductive film in which the current collecting portion of a metal fine line pattern was exposed, while the remaining metal fine line patterns were covered by the protective layer. Specifically, the current collecting portion formed using the above method was masked, a protective layer was formed, and finally the mask was removed to produce a conductive film in which only the current collecting portion was exposed. The results are shown in Table 7 below.

[0648] R s0 =R / L×D

[0649] L: 80 (mm): Distance between current collectors

[0650] D: 100 (mm): Depth of the measurement sample

[0651] [Example D: Visible Light Transmittance and Haze]

[0652] The visible light transmittance of the conductive film was measured by calculating the transmittance of visible light with a wavelength of 360 to 830 nm according to the total light transmittance of JIS K 7361-1:1997. Furthermore, the haze of the conductive film was measured according to JIS K 7136:2000. The results are shown in Table 7 below.

[0653] [Example D: STEM-EDX Analysis of Metal Thin Wire Cross Section]

[0654] Using a focused ion beam (FIB), the resulting conductive film was sliced into thin sections with a thickness of 200 nm or less, encompassing a cross section perpendicular to the direction of extension of the metal wires. The resulting thin sections were mounted on the tip of a silicon sample stage and used as measurement samples for STEM-EDX measurements under the following conditions.

[0655] STEM: Hitachi High-Technologies, Inc., scanning transmission electron microscope HD-2300A

[0656] EDX: EDAX, energy dispersive X-ray analyzer, GENESIS

[0657] Accelerating voltage: 200 kV

[0658] Measurement magnification: 25,000 times

[0659] Electron beam incident angle: 90°

[0660] X-ray extraction angle: 18°

[0661] Mapping elements: Cu, C, O

[0662] Cumulative times: 200 times

[0663] dwell time: 200μsec.

[0664] Resolution: 256 × 200 pixels

[0665] Next, the sample obtained by the above operation is observed using STEM to obtain a STEM image of the cross section of the metal wire. Simultaneously, elemental mapping of the cross section of the metal wire is performed using energy dispersive X-ray analysis (EDX). Specifically, the EDX intensity of the K layer of carbon atoms C, the EDX intensity of the K layer of oxygen atoms O, and the EDX intensity of the K layer of conductive metal atoms M are measured at each location in the cross section. This operation is performed on the entire cross section of the metal wire.

[0666] On the other hand, the maximum thickness T from the metal wire interface on the transparent substrate side to the metal wire is calculated based on the STEM image. The cumulative value of the EDX intensity of the K layer of carbon atoms C and the cumulative value of the EDX intensity of the K layer of conductive metal atoms M in the thickness region of 0.10T to 0.25T from the metal wire interface on the transparent substrate side are calculated. The ratio of these cumulative values is obtained as the atomic % ratio C / M 0.10～0.25 Similarly, the cumulative EDX intensity of the K layer of oxygen atoms O and the cumulative EDX intensity of the K layer of conductive metal atoms M in the thickness region of 0.10T to 0.90T from the metal fine wire interface on the transparent substrate side are calculated, and the ratio of these cumulative values is obtained as the atomic % ratio O / M 0.10～0.90 In addition, for the atomic % ratio O / M 0.75～0.90 , atomic % ratio O / M 0.10～0.25 The calculation was performed in the same manner in the target thickness region. The results are shown in Table 7 below.

[0667] [Example D: Adhesion]

[0668] The 180° peel test method was used to evaluate the adhesion of the metal wires to the transparent substrate of the resulting conductive film. Specifically, KAPTON Adhesive Tape 650S manufactured by TERAOKA was affixed to the metal wire portion (conductive portion) of the resulting conductive film. One end was peeled off from the conductive film, and the tape was peeled off while being folded 180°. The surface of the transparent substrate after the tape was peeled was observed, and the case where no peeling occurred was judged as A, the case where peeling of some metal wires was observed was judged as B, and the case where all metal wires were peeled was judged as C. The results are shown in Table 7 below.

[0669] <Examples D2 to D13 and Comparative Examples D1 to D8>

[0670] Conductive thin films were prepared and evaluated in the same manner as in Example D1 except that the transparent substrate, ink, line width, and firing conditions were changed as shown in Table 7. The results are shown in Table 7 below.

[0671] [Table 7]

[0672]

[0673] From Examples D1 to D13 and Comparative Examples D1 to D8, it can be seen that in the STEM-EDX analysis of the cross section of the metal thin wire perpendicular to the extending direction of the metal thin wire, the atomic % ratio C / M of the conductive metal atoms M to the oxygen atoms C is used to determine the conductivity of the metal thin wire. 0.10～0.25 The atomic % ratio of the conductive metal atoms M to the oxygen atoms O is adjusted to be within the range of 0.3 to 6.0. 0.10～0.90 By adjusting the ratio to a range of 0.01 to 1.00, a conductive film can be obtained that realizes low visibility due to thinning of the lines while achieving low sheet resistance, high transmittance, low haze, and good adhesion.

[0674] This application is based on Japanese patent applications (Japanese Patent Application Nos. 2018-142225, 2018-142051, and 2018-142045) filed with the Japan Patent Office on July 30, 2018, the contents of which are incorporated herein by reference.

[0675] Industrial applicability

[0676] The conductive film of the present invention can be suitably used as a transparent electrode for electronic paper, touch panels, flat panel displays, and the like, and has industrial applicability.

[0677] Description of Reference Numerals

[0678] 10…Conductive film

[0679] 11…Transparent substrate

[0680] 12…Metallic fine line pattern

[0681] 13…Conductive part

[0682] 14…thin metal wire

[0683] 15…Opening

[0684] 16…Pattern unit

[0685] 20…E-paper

[0686] 21...cups

[0687] 22…black pigment

[0688] 23…white pigment

[0689] 24…Bottom electrode

[0690] 30…Touch panel

[0691] 31…Insulator

[0692] 32…Remove the electrodes

[0693] 33…Controller

Claims

1. A conductive film comprising a transparent substrate and a conductive portion comprising a metal fine line pattern disposed on one or both surfaces of the transparent substrate, wherein: The metal fine line pattern is composed of metal fine lines, The metal thin wire contains conductive metal atoms M and silicon atoms Si. In the STEM-EDX analysis of the cross section of the metal fine wire perpendicular to the extending direction of the metal fine wire, when the maximum thickness of the metal fine wire is recorded as T, the atomic % ratio Si of the silicon atoms Si to the conductive metal atoms M in the thickness region of 0.10T to 0.90T from the metal fine wire interface on the transparent substrate side is Si / M 0.10～0.90 The atomic % ratio Si / M in the thickness region of 0.10T to 0.25T from the metal thin wire interface on the transparent substrate side is 0.001 or more and 0.070 or less. 0.10～0.25 The atomic % ratio Si / M in the thickness region of 0.75T to 0.90T from the metal thin wire interface on the transparent substrate side is 0.001 or more and 0.070 or less. 0.75～0.90 is 0.001 or more and 0.070 or less, The conductive metal atoms M include at least one metal element selected from the group consisting of gold, silver, and copper. The line width of the metal thin wire is greater than or equal to 0.1 μm and less than or equal to 5.0 μm.

2. The conductive film according to claim 1, wherein The atomic % ratio Si / M 0.10～0.90 It is 0.003 or more and 0.065 or less.

3. The conductive film according to claim 1, wherein The atomic % ratio Si / M 0.10～0.90 It is 0.005 or more and 0.063 or less.

4. The conductive film according to claim 1, wherein The atomic % ratio Si / M 0.10～0.25 It is 0.003 or more and 0.065 or less.

5. The conductive film according to claim 1, wherein The atomic % ratio Si / M 0.10～0.25 It is 0.005 or more and 0.063 or less. The conductive film according to claim 1 , wherein The atomic % ratio Si / M 0.75～0.90 It is 0.003 or more and 0.065 or less.

7. The conductive film according to claim 1, wherein The atomic % ratio Si / M 0.75～0.90 It is 0.005 or more and 0.063 or less.

8. The conductive film according to any one of claims 1 to 5, wherein An intermediate layer is provided between the transparent substrate and the conductive portion.

9. The conductive film according to claim 8, wherein The intermediate layer includes at least one selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride.

10. The conductive film according to any one of claims 1 to 5, wherein The aspect ratio of the thin metal wire is greater than or equal to 0.05 and less than or equal to 1.

00.

11. The conductive film according to any one of claims 1 to 5, wherein The conductive film has a sheet resistance of 0.1 Ω / sq or more and 1,000 Ω / sq or less.

12. The conductive film according to any one of claims 1 to 5, wherein The conductive film has a visible light transmittance of 80% or more and 100% or less.

13. The conductive film according to any one of claims 1 to 5, wherein The conductive film has a haze of 0.01% or more and 5.00% or less.

14. The conductive film according to any one of claims 1 to 5, wherein The opening ratio of the metal fine line pattern is greater than or equal to 80% and less than 100%.

15. The conductive film according to any one of claims 1 to 5, wherein The metal fine line pattern is a grid pattern.

16. The conductive film according to any one of claims 1 to 5, wherein The metal fine line pattern is a line pattern. 17 . A conductive film roll, comprising: a conductive film according to claim 1 ; and a conductive film roll wound up. 18 . Electronic paper comprising the conductive film according to claim 1 . 19 . A touch panel comprising the conductive film according to claim 1 . 20 . A flat panel display comprising the conductive film according to claim 1 .

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