Transparent conductive layer and transparent conductive sheet

Abstract

The transparent conductive layer (3) has a first main surface (5) and a second main surface (6) facing the first main surface (5) in the thickness direction. The transparent conductive layer (3) has a first grain boundary (7) in which both end edges (23) when viewed in cross-section are open to the first main surface (5) and an intermediate region (25) between the two end edges (23) does not come into contact with the second main surface (6), and a first crystal grain (31) that is divided by the first grain boundary (7) and faces only the first main surface (5). The transparent conductive layer (3) contains noble gas atoms having an atomic number greater than that of argon atoms.

Description

Technology Field

[0001] The present invention relates to a transparent conductive layer and a transparent conductive sheet. Background Technology

[0002] Conventionally, a transparent conductive sheet having a crystalline transparent conductive layer is known.

[0003] For example, a light-transmitting conductive film having a light-transmitting conductive layer having a plurality of crystal grains has been proposed (for example, see Patent Document 1 below).

[0004] In the light-transmitting conductive layer described in Patent Document 1, grain boundaries dividing the aforementioned plurality of crystal grains exist, and grain boundaries extending from the upper surface to the lower surface of the light-transmitting conductive layer.

[0005] In addition, the light-transmitting conductive layer of Patent Document 1 is formed into a wiring pattern by etching. Prior art literature

[0006] Japanese Patent Publication No. 2018-41059 The problem to be solved

[0007] A light-transmitting conductive layer may be etched for reasons such as forming a wiring pattern or design. Recently, a high etching rate is required for the light-transmitting conductive layer to improve the productivity of the etching process. However, the light-transmitting conductive layer described in Patent Document 1 has a problem in that it cannot satisfy the above requirements.

[0008] In addition, such a light-transmitting conductive layer requires low resistance.

[0009] The present invention provides a transparent conductive layer and a transparent conductive sheet having low resistance and a high etching rate. means of solving the problem

[0010] The present invention [1] is a transparent conductive layer having a first main surface and a second main surface facing the first main surface in the thickness direction, a grain boundary in which both end edges are open to the first main surface when viewed in cross-section and an intermediate region between the two end edges does not contact the second main surface, and a first crystal grain that is divided by the grain boundary and faces only the first main surface and contains a noble gas atom having an atomic number greater than that of an argon atom.

[0011] The present invention [2] includes a transparent conductive layer described in [1], comprising a region that is a single layer extending in a plane direction orthogonal to the thickness direction.

[0012] The present invention [3] comprises a transparent conductive layer described in [1] or [2], further having a second grain boundary that is open on the side connecting one end edge of the first main body and one end edge of the second main body.

[0013] The present invention [4] includes a transparent conductive layer described in any one of claims [1] to [3], wherein the material of the transparent conductive layer is a tin-containing oxide.

[0014] The present invention [5] comprises a transparent conductive sheet having a transparent conductive layer described in any one of claims [1] to [4] and a substrate layer located on the second main side of the transparent conductive layer. Effects of the invention

[0015] The transparent conductive layer of the present invention has a grain boundary in which both end edges are open to the first main surface when viewed in cross-section, and an intermediate region between the two end edges does not come into contact with the second main surface, and a first crystal grain that is divided by the grain boundary and faces only the first main surface.

[0016] In this transparent conductive layer, when an etching solution comes into contact with the first surface, the etching solution easily penetrates into the grain boundaries from the two end edges. Consequently, the first crystal grains separated by these grain boundaries are easily exfoliated. As a result, the etching rate of the transparent conductive layer is high.

[0017] Furthermore, this transparent conductive layer contains noble gas atoms with an atomic number greater than that of argon atoms. Specifically, when the transparent conductive layer is manufactured by the sputtering method, atoms originating from the sputtering gas are introduced into the transparent conductive layer. These atoms originating from the sputtering gas inhibit the crystallization of the transparent conductive layer. As a result, the resistivity of the transparent conductive layer increases.

[0018] Meanwhile, this transparent conductive layer is obtained by using a noble gas with an atomic number greater than that of argon as the sputtering gas. Since noble gases with atomic numbers greater than that of argon have a larger atomic weight, they can suppress the introduction of atoms originating from noble gases with atomic numbers greater than that of argon into the transparent conductive layer. In other words, this transparent conductive layer contains atoms originating from noble gases with atomic numbers greater than that of argon, but as mentioned above, their amount is suppressed. Therefore, it is possible to suppress the inhibition of crystallization of the transparent conductive layer by atoms originating from noble gases with atomic numbers greater than that of argon. As a result, the resistivity of the transparent conductive layer can be lowered.

[0019] The transparent conductive sheet of the present invention comprises a transparent conductive layer of the present invention. Therefore, it has low resistance and also has a high etching rate. Brief explanation of the drawing

[0020] FIG. 1 is a schematic diagram showing one embodiment of the transparent conductive layer and transparent conductive sheet of the present invention. FIG. 2 shows a cross-sectional view of a transparent conductive layer in a transparent conductive sheet shown in FIG. 1. FIG. 3 is a schematic diagram illustrating an embodiment of a method for manufacturing a transparent conductive layer and a transparent conductive sheet according to the present invention. FIG. 3A illustrates a process of preparing a transparent substrate in a first process. FIG. 3B illustrates a process of placing a hard coat layer on one side in the thickness direction of the transparent substrate in the first process. FIG. 3C illustrates a second process of placing a transparent conductive layer on one side in the thickness direction of the substrate layer. FIG. 3D illustrates a third process of heating the transparent conductive layer. Figure 4 is a graph showing the relationship between the resistivity of an amorphous transparent conductive layer and the amount of oxygen introduced. FIG. 5 shows a schematic diagram of a modified example of the transparent conductive layer of the present invention (a modified example in which a fourth crystal grain is divided by two third grain boundaries). FIG. 6 shows a schematic diagram of a modified example of a transparent conductive layer of the present invention (a modified example including a fifth crystal grain that does not face any of the first main surface, the second main surface, or the side surface). FIG. 7 shows a schematic diagram of a modified example of the transparent conductive layer of the present invention (a modified example in which the first grain boundary does not include a branching point). FIG. 8 shows a schematic diagram of a modified example of the transparent conductive sheet of the present invention (a modified example having a first transparent conductive layer that does not contain noble gas atoms). Specific details for implementing the invention

[0021] An embodiment of the transparent conductive layer and transparent conductive sheet of the present invention will be described with reference to FIG. 1 and FIG. 2. In FIG. 2, a plurality of crystal grains (4) (described later) are clearly shown, and in order to distinguish between the first grain boundary (7) (described later) to the third grain boundary (9) (described later) and the lead line and virtual line segment (dashed line), the plurality of crystal grains (4) are depicted in grays of different concentrations.

[0022] Transparent conductive sheet

[0023] As shown in FIG. 1, this transparent conductive sheet (1) has a predetermined thickness and has a sheet shape extending in a plane direction orthogonal to the thickness direction. This transparent conductive sheet (1) has a substrate layer (2) and a transparent conductive layer (3) arranged in sequence toward one side of the thickness direction. Specifically, the transparent conductive sheet (1) has a substrate layer (2) and a transparent conductive layer (3) disposed on one side of the thickness direction of the substrate layer (2).

[0024] <Source Class>

[0025] The substrate layer (2) is a transparent substrate for securing the mechanical strength of the transparent conductive sheet (1). The substrate layer (2) extends in the plane direction. The substrate layer (2) has a first substrate surface (21) and a second substrate surface (22). The first substrate surface (21) is a flat surface. The second substrate surface (22) is spaced apart and positioned opposite the first substrate surface (21) in the thickness direction. Additionally, the substrate layer (2) is located on the side of the second substrate surface (6) (described later) of the transparent conductive layer (3). The second substrate surface (22) is parallel to the first substrate surface (21).

[0026] In addition, the flat surface does not matter whether the first main surface (21) of the substrate layer (2) and the second main surface (22) of the substrate layer (2) are approximately parallel planes. For example, fine irregularities and undulations that are not observable are allowed.

[0027] The substrate layer (2) is equipped with a transparent substrate (41) and a functional layer (42).

[0028] Specifically, the substrate layer (2) comprises a transparent substrate (41) and a functional layer (42) in sequence toward one side in the thickness direction. Specifically, the substrate layer (2) comprises a transparent substrate (41) and a functional layer (42) disposed on one side in the thickness direction of the transparent substrate (41).

[0029] <Transparent Entry>

[0030] The transparent substrate (41) has a film shape.

[0031] Examples of materials for the transparent substrate (41) include olefin resin, polyester resin, (meth)acrylic resin (acrylic resin and / or methacrylic resin), polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, and polystyrene resin. Examples of olefin resins include polyethylene, polypropylene, and cycloolefin polymers. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of (meth)acrylic resins include polymethacrylate. As for the material of the transparent substrate (41), in terms of transparency and moisture permeability, polyester resin is preferably used, and more preferably polyethylene terephthalate (PET).

[0032] The transparent substrate (41) has transparency. Specifically, the total light transmittance (JIS K 7375-2008) of the transparent substrate (41) is, for example, 60% or more, preferably 80% or more, more preferably 85% or more.

[0033] The thickness of the transparent substrate (41) is, for example, 1 μm or more, preferably 10 μm or more, more preferably 30 μm or more, and, for example, 1000 μm or less, preferably 500 μm or less, more preferably 250 μm or less, even more preferably 200 μm or less, particularly preferably 100 μm or less, most preferably 60 μm or less.

[0034] Functional layer

[0035] The functional layer (42) is disposed on one side in the thickness direction of the transparent substrate (41).

[0036] The functional layer (42) has a film shape.

[0037] As for the functional layer (42), for example, a hard coat layer can be used.

[0038] In this case, the substrate layer (2) is provided with a transparent substrate (41) and a hard coat layer in sequence facing one side in the thickness direction.

[0039] In the following description, the case where the functional layer (42) is a hard coat layer is described.

[0040] The hard coat layer is a protective layer to prevent scratches from occurring on the transparent conductive sheet (1).

[0041] The hard coat layer is formed, for example, from a hard coat composition.

[0042] The hard coat composition contains a resin and, if necessary, particles. In short, the hard coat layer contains a resin and, if necessary, particles.

[0043] Examples of resins include thermoplastic resins and curable resins. Examples of thermoplastic resins include polyolefin resins.

[0044] Examples of curable resins include active energy beam curable resins that are cured by irradiation with active energy beams (e.g., ultraviolet and electron beams), and thermosetting resins that are cured by heating. Preferably, examples of curable resins include active energy beam curable resins.

[0045] Examples of active energy beam curable resins include (meth)acrylic UV-curable resins, urethane resins, melamine resins, alkyd resins, siloxane-based polymers, and organic silane condensates. Preferably, (meth)acrylic UV-curable resins are examples of active energy beam curable resins.

[0046] In addition, the resin may contain a reactive diluent as described in, for example, Japanese Patent Publication No. 2008-88309. Specifically, the resin may contain a polyfunctional (meth)acrylate.

[0047] The resin can be used alone or in combination with two or more types.

[0048] Examples of particles include metal oxide microparticles and organic microparticles. Examples of materials for metal oxide microparticles include silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. Examples of materials for organic microparticles include polymethyl methacrylate, silicon, polystyrene, polyurethane, acrylic-styrene copolymer, benzoguanamine, melamine, and polycarbonate.

[0049] The particles can be used alone or in combination of two or more types.

[0050] In addition, the hard coat composition may, if necessary, incorporate a thixotropy-importing agent, a photopolymerization initiator, a filler (e.g., organic clay), and a leveling agent in appropriate proportions. In addition, the hard coat composition may be diluted with a known solvent.

[0051] In addition, to form a hard coat layer, a diluted solution of the hard coat composition is applied to one side of the thickness direction of the transparent substrate (41), as described in detail later, and is heated and dried as needed. After drying, the hard coat composition is cured, for example, by irradiation with an active energy beam.

[0052] Thus, a hard coat layer is formed.

[0053] The thickness of the hard coat layer is, for example, 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more, and, for example, 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less.

[0054] Transparent Challenge Layer

[0055] The transparent conductive layer (3) is disposed on one side in the thickness direction of the substrate layer (2). Specifically, the transparent conductive layer (3) is in contact with the entire surface of the first main surface (21) of the substrate sheet (2). The transparent conductive layer (3) has a predetermined thickness and preferably includes a region that is a single layer extending in a plane direction orthogonal to the thickness direction, and more preferably is a single layer extending in a plane direction orthogonal to the thickness direction. Specifically, preferably, the transparent conductive layer (3) includes a region that is not a plurality of layers stacked in the thickness direction, and more preferably, the transparent conductive layer (3) is not a plurality of layers stacked in the thickness direction. More specifically, as a plurality of transparent conductive layers divided along the plane direction, it is preferable that a plurality of transparent conductive layers including a boundary parallel to the first main surface (21) of the substrate layer (2) are not included in the transparent conductive layer of the present invention.

[0056] The transparent conductive layer (3) has a first main surface (5) and a second main surface (6) that face each other in the thickness direction.

[0057] The first main surface (5) is exposed in one direction in the thickness direction. The first main surface (5) is a flat surface.

[0058] The second main surface (6) is spaced apart and positioned oppositely on the other side in the thickness direction of the first main surface (5). The second main surface (6) is a flat surface parallel to the first main surface (21). In this embodiment, the second main surface (6) contacts the substrate first main surface (21).

[0059] In addition, the flat surface does not matter whether the first surface (5) and the second surface (6) are approximately parallel planes. For example, fine irregularities and undulations that are not observable are allowed.

[0060] As shown in FIG. 2, the side (55) connects the perimeter end edge of the first main body (5) and the perimeter end edge of the second main body (6). When viewed in cross-section, the side (55) has a one side (56) connecting one end edge of the first main body (5) and one end edge of the second main body (6), and a other side (not shown) connecting the other end edge of the first main body (5) and the other end edge of the second main body (6).

[0061] This transparent conductive layer (3) is crystalline. Preferably, the transparent conductive layer (3) does not include amorphous regions in the plane direction and includes only crystalline regions. Additionally, a transparent conductive layer that includes amorphous regions is identified, for example, by observing the crystal grains in the plane direction of the transparent conductive layer using TEM.

[0062] In the case where the transparent conductive layer (3) is crystalline, for example, the transparent conductive layer (3) is immersed in a 5 mass% aqueous hydrochloric acid solution for 15 minutes, then washed and dried, and the resistance between two terminals is measured at a distance of about 15 mm on the first main surface (5), and the resistance between two terminals is 10 kΩ or less. On the other hand, if the resistance between two terminals is greater than 10 kΩ, the transparent conductive layer (3) is amorphous.

[0063] The transparent conductive layer (3) has a plurality of crystal grains (4). The crystal grains (4) are sometimes referred to as grains. The crystal grains (4) include first crystal grains (31) separated by a first grain boundary (7) as an example of a grain boundary.

[0064] The first crystal grain (31) does not face the second main surface (6) and the side surface (55), but faces the first main surface (5). In short, the first crystal grain (31) faces only the first main surface (5).

[0065] The first grain boundary (7) includes two end edges (23). Additionally, the first grain boundary (7) is open to the first main surface (5). In the first grain boundary (7), the intermediate region (25) between the two end edges (23) does not come into contact with the second main surface (6) and the side surface (55). The first grain boundary (7) has a roughly U-shape that is open toward one side in the thickness direction when viewed in cross-section. Also, the first grain boundary (7) has a path that extends from one end edge (23) toward the other side in the thickness direction, proceeds in the width direction (an example of a direction perpendicular to the thickness direction) in the middle of the thickness direction, and then returns to the other end edge (23) toward one side in the thickness direction. Additionally, the first grain boundary (7) may have a path that proceeds from the edge (23) toward the other side in the thickness direction, and then, in the middle of the thickness direction, turns around and returns to the other edge (23) toward the side in the thickness direction.

[0066] Also, although not shown, the first crystal grain (31) may be formed in multiple places in the transparent conductive layer (3). In this case, the respective end edges (23) of adjacent transparent conductive layers (3) may be common.

[0067] Also, in this embodiment, the intermediate region (25) of the first grain boundary (7) includes the first branch point (26) and the second branch point (27).

[0068] Starting from the first branching point (26), the second grain boundary (8) branches off from the first grain boundary (7). Also, the second grain boundary (8) has one edge included in the intermediate region (25), and the other edge is open to one side (56) (side (55)). Then, the second grain (32) is divided by the second grain boundary (8) and the part extending from the first edge (23) of the first grain boundary (7) to the middle part of the intermediate region (25).

[0069] The second crystal grain (32) does not face the second main surface (6), but faces the first main surface (5) and one side surface (56). In short, the second crystal grain (32) faces only the first main surface (5) and one side surface (56).

[0070] Also, starting from the second branching point (27), the third grain boundary (9) branches off from the first grain boundary (7). The third grain boundary (9) has one edge included in the intermediate region (25), and the other edge open to the second main surface (6). Then, the third grain (33) is divided by the third grain boundary (9), the intermediate region (25) of the first grain boundary (7), and the second grain boundary (8).

[0071] The third crystal grain (33) does not face the first main surface (5), but faces the second main surface (6) and one side surface (56). In short, the third crystal grain (33) faces only the second main surface (6) and one side surface (56).

[0072] In addition, the transparent conductive layer (3) may include a fourth crystal grain (44) facing both sides of the first main surface (5) and the second main surface (6).

[0073] The transparent conductive layer (3) may be a crystalline layer containing a first crystal grain (31), and the ratio of the first crystal grain (31) to other crystal grains such as a second crystal grain (32), a third crystal grain (33), and a fourth crystal grain (44) is arbitrary.

[0074] The first grain boundary (7), the second grain boundary (8), and the third grain boundary can be formed by adjusting, for example, the temperature of the substrate layer (2) during sputtering, the pressure of the film formation, the magnetic field strength of the target surface, and the thickness of the transparent conductive layer (3).

[0075] The transparent conductive layer (3) contains a material and a trace amount of a noble gas atom having an atomic number greater than that of an argon atom (hereinafter referred to as the first noble gas atom). The transparent conductive layer (3) is preferably composed of a material and a trace amount of the first noble gas atom. Specifically, in the transparent conductive layer (3), a trace amount of the first noble gas atom exists in the material matrix.

[0076] The material is not particularly limited. Examples of materials include metal oxides containing at least one metal selected from the group consisting of In, Sn, Zn, Ga, Sb, Nb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, and W.

[0077] Specifically, examples of metal oxides include tin-containing oxides, indium-zinc composite oxides (IZO), indium-gallium-zinc composite oxides (IGZO), and indium-gallium composite oxides (IGO). Examples of tin-containing oxides include indium-tin composite oxides (ITO) and antimony-tin composite oxides (ATO). Preferably, tin-containing oxides are metal oxides. If the material is a tin-containing oxide, it has excellent transparency and electrical conductivity.

[0078] The content of tin oxide (SnO2) in the transparent conductive layer (3) (tin-containing oxide) is not particularly limited, for example, 0.5 mass% or more, preferably 3 mass% or more, more preferably 6 mass% or more, and for example, less than 50 mass%, preferably 25 mass% or less, more preferably 15 mass% or less.

[0079] The first noble gas atom may be, for example, a krypton atom and a xenon atom, preferably a krypton atom.

[0080] The first noble gas atom originates from the first noble gas as a sputtering gas described later. In other words, although described in detail later, in the sputtering method, the first noble gas atom originating from the first noble gas as a sputtering gas (described later) is introduced into the transparent conductive layer (3).

[0081] The content of the first noble gas atom in the transparent conductive layer (3) is, for example, 1.0 atomic% or less, more preferably 0.7 atomic% or less, even more preferably 0.5 atomic% or less, particularly preferably 0.3 atomic% or less, most preferably 0.2 atomic% or less, furthermore less than 0.1 atomic%, and for example 0.0001 atomic% or more.

[0082] The content of the first noble gas atom can be measured, for example, by Rutherford backscattering spectroscopy. Also, the presence of the first noble gas atom can be confirmed, for example, by fluorescence X-ray analysis. In the case where the content of the first noble gas atom in the transparent conductive layer (3) is excessively low (specifically, when the content of the first noble gas atom is not above the detection limit value (lower limit) of Rutherford backscattering analysis), the content of the first noble gas atom may not be quantified by Rutherford backscattering analysis. However, in the present invention, even in such a case, if the presence of the first noble gas atom is identified by fluorescence X-ray analysis, the content of the first noble gas atom is determined to be at least 0.0001 atomic% or more.

[0083] The thickness of the transparent conductive layer (3) is, for example, 40 nm or more, preferably 60 nm or more, more preferably 70 nm or more, even more preferably 100 nm or more, particularly preferably 120 nm or more, most preferably 140 nm or more in terms of moisture permeability, and in terms of thinning, for example 1000 nm or less, preferably 500 nm or less, more preferably less than 300 nm, even more preferably less than 200 nm, particularly preferably less than 150 nm, most preferably 148 nm or less. The method for determining the thickness of the transparent conductive layer (3) will be described in detail in the following examples.

[0084] The ratio of the length between two end edges (23) when viewed in cross-section to the thickness of the transparent conductive layer (3) (the average length when there are multiple first crystal grains (31)) is, for example, 0.1 or more, preferably 0.25 or more, and, for example, 20 or less, preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. If the above ratio exceeds the above lower limit and falls below the above upper limit, the etching speed of the transparent conductive layer (3) can be increased.

[0085] The maximum crystal grain size in the plurality of crystal grains (4) is not particularly limited, for example, 500 nm or less, preferably 400 nm or less, more preferably 350 nm or less, even more preferably 300 nm or less, particularly preferably 250 nm or less, most preferably 200 nm or less, and also, for example, 1 nm or more, preferably 10 nm or more. If the maximum crystal grain size in the plurality of crystal grains (4) is less than or equal to the upper limit mentioned above, the amount of the first grain boundary (7) per unit area in the first main surface (5) of the transparent conductive layer (3) can be increased, and thus, the etching speed can be increased.

[0086] The surface resistance of the transparent conductive layer (3) is, for example, 200 Ω / □ or less, preferably 50 Ω / □ or less, more preferably 30 Ω / □ or less, even more preferably 20 Ω / □ or less, particularly preferably 15 Ω / □ or less, and also, for example, greater than 0 Ω / □.

[0087] The resistivity of the transparent conductive layer (3) is, for example, 2.2×10 -4 Ω·cm or less, preferably 1.8×10⁻⁶ -4 Ω·cm or less, more preferably 1.6×10⁻⁶ -4 Ω·cm or less, more preferably 1.0×10⁻⁶ -4It is Ω·cm or less. In addition, the above resistivity value is, for example, 0.1×10⁻⁶ -4 Ω·cm or more, preferably 0.5×10⁻⁶ -4 Ω·cm or more, more preferably 1.0×10⁻⁶ -4 Ω·cm or more, more preferably 1.01×10⁻⁶ -4 It is greater than Ω·cm. The resistivity value can be obtained by multiplying the thickness of the transparent conductive layer (3) by the value of the surface resistance.

[0088] Method for manufacturing a transparent conductive layer and a transparent conductive sheet

[0089] A method for manufacturing a transparent conductive layer (3) and a transparent conductive sheet (1) is described with reference to FIG. 3.

[0090] A method for manufacturing a transparent conductive layer (3) and a transparent conductive sheet (1) comprises a first step of preparing a substrate layer (2), a second step of placing a transparent conductive layer (3) on one side in the thickness direction of the substrate layer (2), and a third step of heating the transparent conductive layer (3). In addition, in this manufacturing method, each layer is arranged in sequence, for example, in a roll-to-roll manner.

[0091] <Process 1>

[0092] In the first process, a substrate layer (2) is prepared.

[0093] In order to prepare the substrate layer (2), as shown in FIG. 3A, a transparent substrate (3) is first prepared.

[0094] Next, as shown in FIG. 3B, a diluted solution of the hard coat composition is applied to one side in the thickness direction of the transparent substrate (41), and after drying, the hard coat composition is cured by ultraviolet irradiation or heating. In this way, a hard coat layer (functional layer (42)) is formed on one side in the thickness direction of the transparent substrate (41). In this way, the substrate layer (2) is prepared.

[0095] <Process 2>

[0096] In the second process, as shown in FIG. 3C, a transparent conductive layer (3) is placed on one side in the thickness direction of the substrate layer (2).

[0097] Specifically, in a sputtering apparatus, sputtering is performed in the presence of a sputtering gas while facing one side of the thickness direction of the substrate layer (2) toward a target made of the material of the transparent conductive layer (3). Also, in the sputtering, the substrate layer (2) is in close contact along the circumferential direction of the film-forming roll. In addition, at this time, in addition to the sputtering gas, for example, a reactive gas (e.g., oxygen) may be present.

[0098] The sputtering gas is a noble gas having an atomic number greater than that of an argon atom (hereinafter referred to as the first noble gas). Examples of the first noble gas include krypton gas and xenon gas, and preferably krypton gas.

[0099] The partial pressure of the sputtering gas in the sputtering apparatus is, for example, 0.05 Pa or more, preferably 0.1 Pa or more, and also, for example, 10 Pa or less, preferably 5 Pa or less, more preferably 1 Pa or less.

[0100] As shown in FIG. 4, the amount of reactive gas introduced can be estimated by the surface resistance of the amorphous transparent conductive layer (3). Specifically, since the film quality (surface resistance) of the amorphous transparent conductive layer (3) changes depending on the amount of reactive gas introduced into the amorphous transparent conductive layer (3), the amount of reactive gas introduced can be adjusted according to the desired surface resistance of the amorphous transparent conductive layer (3). In addition, in order to obtain a crystal film transparent conductive layer (3) by heating the amorphous transparent conductive layer (3), it is preferable to obtain the amorphous transparent conductive layer (3) by adjusting the amount of reactive gas introduced within the range of area X in FIG. 4.

[0101] Specifically, the resistivity of the amorphous transparent conductive layer (3) is, for example, 8.0×10 -4 Ω·cm or less, preferably 7.0×10⁻⁶ -4 Ω·cm or less, also, for example, 2.0×10⁻⁶ -4 Ω·cm or more, preferably 4.0×10⁻⁶ -4 Ω·cm or more, more preferably 5.0×10⁻⁶ -4 A reactive gas is introduced to make the Ω·cm or higher.

[0102] The pressure within the sputtering apparatus is substantially the sum of the partial pressures of the sputtering gas and the reactive gas.

[0103] The power source may be any of, for example, a DC power source, an AC power source, an MF power source, and an RF power source. It may also be a combination of these.

[0104] The value of the discharge output for the long side of the target is, for example, 0.1 W / mm or more, preferably 0.5 W / mm or more, more preferably 1 W / mm or more, even more preferably 5 W / mm or more, and also, for example, 30 W / mm or less, preferably 15 W / mm or less. In addition, the direction of the long side of the target is, for example, a direction orthogonal to the conveying direction (TD direction) in a roll-to-roll sputtering apparatus.

[0105] The horizontal magnetic field strength on the target surface is, for example, 10 mT or more, preferably 60 mT or more, and also, for example, 300 mT or less. By setting the horizontal magnetic field strength on the target surface to the above range, the amount of the first noble gas atom in the transparent conductive layer (3) can be reduced, thereby enabling the production of a transparent conductive layer (3) with excellent low resistivity.

[0106] Then, the material of the transparent conductive layer (3) ejected from the target by sputtering is deposited on the substrate layer (2). At this time, since thermal energy is generated, preferably, when forming the transparent conductive layer (3), the transparent conductive layer (3) is cooled by cooling the substrate layer (2) with a film-forming roll to suppress crystallization of the transparent conductive layer (3).

[0107] In detail, the temperature of the film-forming roll (and furthermore, the temperature of the substrate layer (2)) is, for example, -50°C or higher, preferably -20°C or higher, more preferably -10°C or higher, and also, for example, 30°C or lower, preferably 20°C or lower, more preferably 15°C or lower, even more preferably 10°C or lower, and particularly preferably 5°C or lower. Within the above temperature range, the substrate layer (2) can be sufficiently cooled, and thus crystal growth during the formation of the transparent conductive layer (3) (especially crystal growth in the thickness direction of the transparent conductive layer (3)) can be suppressed, so that the first crystal grain is easily obtained in the transparent conductive layer (3) after undergoing the third process described later.

[0108] Thus, an amorphous transparent conductive layer (3) is placed on one side in the thickness direction of the substrate layer (2).

[0109] Also, as mentioned above, since the first noble gas is used as the sputtering gas, the first noble gas atoms originating from the first noble gas are introduced into the transparent conductive layer (3).

[0110] <Process 3>

[0111] In the third process, the amorphous transparent conductive layer (3) is heated. For example, the amorphous transparent conductive layer (3) is heated by a heating device (e.g., an infrared heater and a hot air oven).

[0112] The heating temperature is, for example, 80°C or higher, preferably 110°C or higher, and also, for example, less than 200°C, preferably 180°C or lower. In addition, the heating time is, for example, 1 minute or more, preferably 10 minutes or more, more preferably 30 minutes or more, and also, for example, 24 hours or less, preferably 4 hours or less, more preferably 2 hours or less.

[0113] Thus, as shown in Fig. 3D, the amorphous transparent conductive layer (3) is crystallized to form a crystalline transparent conductive layer (3).

[0114] Thus, a transparent conductive layer (3) is obtained, and a transparent conductive sheet (1) having a substrate layer (2) and a transparent conductive layer (3) in sequence is obtained.

[0115] After that, the transparent conductive layer (3) may be patterned. Patterning is performed, for example, by etching.

[0116] When the transparent conductive layer (3) is patterned, the transparent conductive layer (3) has a pattern shape. If the transparent conductive layer (3) has a pattern shape, the pattern shape can be freely designed.

[0117] Articles with a transparent conductive sheet attached and articles with a transparent conductive layer attached

[0118] A transparent conductive sheet (1) can be placed on one side in the thickness direction of the part to obtain an article with a transparent conductive sheet attached.

[0119] An article with a transparent conductive sheet attached comprises a component and a transparent conductive sheet (1) in sequence facing one side in the thickness direction. Specifically, an article with a transparent conductive sheet attached comprises a component, a substrate layer (2), and a transparent conductive layer (3) in sequence facing one side in the thickness direction.

[0120] The articles are not particularly limited and may include, for example, components, parts, and devices. More specifically, components may include, for example, dimming elements and photoelectric conversion elements. Dimming elements may include, for example, current-driven dimming elements and electric field-driven dimming elements. Current-driven dimming elements may include, for example, electrochromic (EC) dimming elements. Electric field-driven dimming elements may include, for example, PDLC (polymer dispersed liquid crystal) dimming elements, PNLC (polymer network liquid crystal) dimming elements, and SPD (suspended particle device) dimming elements. Photoelectric conversion elements may include, for example, solar cells. Solar cells may include, for example, organic thin-film solar cells, perovskite solar cells, and dye-sensitized solar cells. Parts may include, for example, electromagnetic shielding parts, heat wire control parts, heater parts, lighting, and antenna parts. Devices may include, for example, touch sensor devices and image display devices.

[0121] An article with a transparent conductive sheet attached is obtained, for example, by bonding a component and a substrate layer (2) of the transparent conductive sheet (1) through a fixing functional layer.

[0122] Examples of fixing functional layers include adhesive layers and adhesive layers.

[0123] As for the fixing functional layer, any material having transparency can be used without any particular material restrictions. The fixing functional layer is preferably formed of a resin. Examples of resins include acrylic resin, silicone resin, polyester resin, polyurethane resin, polyamide resin, polyvinyl ether resin, vinyl acetate / vinyl chloride copolymer, modified polyolefin resin, epoxy resin, fluoropolymer, natural rubber, and synthetic rubber. In particular, acrylic resin is preferably selected as the resin from the view that it has excellent optical transparency, exhibits adhesive properties such as suitable wettability, cohesiveness, and adhesion, and also has excellent weather resistance and heat resistance.

[0124] In order to suppress corrosion and migration of the transparent conductive layer (3), known corrosion inhibitors and migration inhibitors (e.g., materials disclosed in Japanese Patent Publication No. 2015-022397) may be added to the adhesive functional layer (resin forming the adhesive functional layer). In addition, in order to suppress deterioration of the article with the transparent conductive sheet attached during outdoor use, known ultraviolet absorbers may be added to the adhesive functional layer (resin forming the adhesive functional layer). Examples of ultraviolet absorbers include benzophenone-based compounds, benzotriazole-based compounds, salicylic acid-based compounds, oxalate anilide-based compounds, cyanoacrylate-based compounds, and triazine-based compounds.

[0125] In addition, a cover layer may be placed on the upper surface of the transparent conductive layer (3) in an article to which a transparent conductive sheet is attached.

[0126] The cover layer is a layer that covers the transparent conductive layer (3), and can improve the reliability of the transparent conductive layer (3) and suppress functional deterioration caused by scratches.

[0127] The cover layer is preferably a dielectric. The cover layer is formed from a mixture of a resin and an inorganic material. Examples of resins include the resins exemplified in the fixing functional layer. The inorganic material is composed of a composition containing, for example, inorganic oxides such as silicon oxide, titanium oxide, niobium oxide, aluminum oxide, zirconium dioxide, and calcium oxide, and fluorides such as magnesium fluoride.

[0128] In addition, a corrosion inhibitor, a migration inhibitor, and a UV absorber may be added to the cover layer (a mixture of resin and inorganic materials) in the same way as the adhesive functional layer described above.

[0129] In addition, by bonding the transparent conductive layer (3) of the transparent conductive sheet (1) to the parts through a fixing functional layer, an article with a transparent conductive sheet attached can be obtained.

[0130] In addition, a transparent conductive layer (3) can be placed on one side in the thickness direction of the part to obtain an article with a transparent conductive layer attached.

[0131] An article with a transparent conductive layer attached comprises a component and a transparent conductive layer (3) in sequence facing one side in the thickness direction.

[0132] An article with a transparent conductive layer attached is obtained by placing a transparent conductive layer (3) on one side of the thickness direction of a part by a sputtering method, or by transferring a transparent conductive layer (3) from a transparent conductive sheet (1) on one side of the thickness direction of a part.

[0133] In addition, the component and the transparent conductive layer (3) may be bonded together through the adhesive functional layer.

[0134] In addition, a cover layer may be placed on the upper surface of the transparent conductive layer (3) in an article with a transparent conductive layer attached.

[0135] <Effect of operation of one embodiment>

[0136] In this transparent conductive layer (3), when an etching solution comes into contact with the first main surface (5), the etching solution is likely to penetrate into the first grain boundary (7) from the two end edges (23). Because of this, the first crystal grain (31) separated by the first grain boundary (7) is easily etched. Specifically, since both end edges (23) of the first grain boundary (7) separating the first crystal grain (31) face the first main surface (5), when the etching solution penetrates into the first grain boundary (7), the etching solution from both end edges (23) merges in the intermediate region (25). The first crystal grain (31) is not supported by the third crystal grain (33) facing the second main surface (6), for example, and is easily etched (including missing or detached) from the transparent conductive layer (3). As a result, the etching rate of the transparent conductive layer (3) is high in this transparent conductive sheet (1).

[0137] Also, in this transparent conductive layer (3), when an etching solution comes into contact with one side (56), the etching solution is likely to penetrate into the second grain boundary (8). Because of this, the second crystal grain (32) separated by the second grain boundary (8) is easily easily peeled off. As a result, in this transparent conductive sheet (1), the etching rate of the transparent conductive layer (3) is even higher.

[0138] Meanwhile, if the transparent conductive layer (3) has a first grain boundary (7) and a first crystal grain (31), the resistivity tends to increase in terms of carrier mobility.

[0139] However, the transparent conductive layer (3) contains atoms (first noble gas atoms) derived from the sputtering gas. Because of this, even if the transparent conductive layer (3) has first grain boundaries (7) and second grain boundaries (8), the resistivity of the transparent conductive layer (3) can be lowered.

[0140] More specifically, when a transparent conductive layer (3) is manufactured by a sputtering method, atoms originating from the sputtering gas are introduced into the transparent conductive layer (3). Such atoms originating from the sputtering gas inhibit the crystallization of the transparent conductive layer (3). As a result, the resistivity of the transparent conductive layer (3) increases.

[0141] Meanwhile, the transparent conductive layer (3) is obtained by using a first noble gas as the sputtering gas. Since the first noble gas has a larger atomic weight than argon, it is possible to suppress the introduction of atoms originating from the first noble gas (first noble gas atoms) into the transparent conductive layer (3). In short, this transparent conductive layer (3) contains atoms originating from the first noble gas (first noble gas atoms), but as described above, the amount is suppressed. Therefore, it is possible to suppress the inhibition of crystallization of the transparent conductive layer (3) by the first noble gas atoms. As a result, the resistivity of the transparent conductive layer (3) can be lowered.

[0142] From the above, the transparent conductive layer (3) can have low resistivity and also high etching speed.

[0143] And, the transparent conductive sheet (1), touch sensor, light-diffusing element, photoelectric conversion element, heat wire control member, antenna, electromagnetic shield member and image display device having such a transparent conductive layer (3) can have low resistivity and also high etching speed.

[0144] <Example of Variation>

[0145] In each of the following variations, the same reference numerals are assigned to components and processes identical to those in the above-described embodiment, and their detailed descriptions are omitted. Furthermore, each variation may exhibit the same functional effects as the embodiment, except as not specified otherwise. Additionally, the embodiment and its variations may be appropriately combined.

[0146] Additionally, as shown in FIG. 5, the transparent conductive layer (3) may be provided with two third grain boundaries (9) at the other end edge that are open to the second main surface (6), and a fourth grain (34) separated by an intermediate region (25) of the first grain boundary (7). The intermediate region (25) includes two second branching points (27).

[0147] The fourth crystal grain (34) does not face the side surface (56) and the first main surface (5), but only the second main surface (6).

[0148] Additionally, as shown in FIG. 6, it may include a fifth crystal grain (57) that does not face any of the first main surface (5), the second main surface (6), or the side surface (55).

[0149] As shown in FIG. 7, the transparent conductive layer (3) does not have the aforementioned third crystal grain (33) and fourth crystal grain (34) (see FIG. 2), and in short, has only crystal grains (4) that do not face the second main surface (6). In this case, the intermediate region (25) does not include the first branching point (26) and the second branching point (27) (see FIG. 2).

[0150] Preferably, as in one embodiment, the intermediate region (25) includes a second branch point (27), and the transparent conductive layer (3) includes a fourth crystal grain (34). Thus, when the etching solution penetrates from the second branch point (27) into the fourth crystal grain (34) and reaches the second main surface (6), the defect of the fourth crystal grain (34) is promoted. Therefore, the etching speed can be increased even further.

[0151] In the above description, the transparent conductive sheet (1) comprises a substrate layer (2) and a transparent conductive layer (3) in sequence facing one side in the thickness direction. Also, in such a transparent conductive sheet (1), the transparent conductive layer (3) contains a first noble gas atom.

[0152] Meanwhile, the transparent conductive sheet (1) may additionally have a transparent conductive layer that does not contain a first noble gas atom (hereinafter referred to as the first noble gas atom-free transparent conductive layer (43)).

[0153] Specifically, as shown in FIG. 8, the transparent conductive sheet (1) comprises a substrate layer (2), a transparent conductive layer (3), and a first transparent conductive layer (43) that does not contain noble gas atoms, arranged in order toward one side in the thickness direction. More specifically, the transparent conductive sheet (1) comprises a substrate layer (2), a transparent conductive layer (3) disposed on one side in the thickness direction of the substrate layer (2), and a first transparent conductive layer (43) that does not contain noble gas atoms disposed on one side in the thickness direction of the transparent conductive layer (3).

[0154] The first noble gas atom-free transparent conductive layer (43) does not contain the first noble gas atom and contains the above material (specifically, the same material as the material contained in the transparent conductive layer (3)) and a trace amount of noble gas atoms having an atomic number less than or equal to that of an argon atom (hereinafter referred to as the second noble gas atom). The first noble gas atom-free transparent conductive layer (43) is preferably composed of the above material and a trace amount of the second noble gas atom. Specifically, in the first noble gas atom-free transparent conductive layer (43), a trace amount of the second noble gas atom exists in the material matrix.

[0155] The second noble gas atom may be, for example, an argon atom, a neon atom, and a helium atom, preferably an argon atom.

[0156] The second noble gas atom originates from the second noble gas as a sputtering gas described later. In other words, although described in detail later, in the sputtering method, the second noble gas atom originating from the second noble gas (described later) as a sputtering gas is introduced into the first noble gas atom-free transparent conductive layer (43).

[0157] Since the second noble gas atom has a smaller atomic weight than the first noble gas atom, the content of the second noble gas atom in the transparent conductive layer (3) is greater than the content of the first noble gas atom. Therefore, the content of the second noble gas atom in the transparent conductive layer (43) that does not contain the first noble gas atom is, specifically, 2.0 atomic% or less, preferably 1.0 atomic% or less, more preferably 0.7 atomic% or less, particularly preferably 0.5 atomic% or less, most preferably 0.3 atomic% or less, furthermore 0.2 atomic% or less, and, for example, 0.0001 atomic% or more.

[0158] The method for confirming the content of the second noble gas atom and the method for confirming the existence of the second noble gas atom are identical to the method for confirming the content of the first noble gas atom and the method for confirming the existence of the first noble gas atom described above.

[0159] The thickness of the first transparent conductive layer (43) that does not contain noble gas atoms is, for example, 1 nm or more, preferably 10 nm or more, more preferably 30 nm or more, even more preferably 70 nm or more, and, for example, 500 nm or less, preferably less than 300 nm, more preferably less than 200 nm, even more preferably less than 150 nm, particularly preferably less than 100 nm. The method for determining the thickness of the first transparent conductive layer (43) that does not contain noble gas atoms is the same as the method for determining the thickness of the transparent conductive layer (3).

[0160] And, in order to place the first noble gas atom-free transparent conductive layer (43) on one side in the thickness direction of the transparent conductive layer (3), in the second process, after placing the transparent conductive layer (3) on one side in the thickness direction of the substrate layer (2), the first noble gas atom-free transparent conductive layer (43) is placed on one side in the thickness direction of the transparent conductive layer (3).

[0161] Specifically, in a sputtering apparatus, sputtering is performed in the presence of a sputtering gas while facing one side in the thickness direction of the transparent conductive layer (3) to a target made of the material of the first noble gas atom-free transparent conductive layer (43). Also, in the sputtering, the transparent conductive layer (3) (specifically, the substrate layer (2) having the transparent conductive layer (3)) is in close contact along the circumferential direction of the film-forming roll. In addition, at this time, in addition to the sputtering gas, for example, a reactive gas (e.g., oxygen) may be present.

[0162] The sputtering gas is a noble gas having an atomic number less than or equal to that of an argon atom (hereinafter referred to as the second noble gas). Examples of the second noble gas include argon gas, neon gas, and helium gas, and preferably argon gas.

[0163] The partial pressure of the sputtering gas in the sputtering device, the amount of reactive gas introduced, the power supply, and the value of the discharge output for the long side of the target are the same as the sputtering conditions when the transparent conductive layer (3) described above is placed.

[0164] Then, the material of the first non-noble gas atom transparent conductive layer (43) that is ejected from the target by sputtering is deposited on the transparent conductive layer (3). At this time, since thermal energy is generated, when the first non-noble gas atom transparent conductive layer (43) is formed, the first non-noble gas atom transparent conductive layer (43) is cooled by cooling the transparent conductive layer (3) by a forming roll, thereby suppressing the crystallization of the first non-noble gas atom transparent conductive layer (43).

[0165] In detail, the temperature of the film-forming roll is the same as the temperature of the film-forming roll in the sputtering process when placing the transparent conductive layer (3) described above.

[0166] Thus, an amorphous first non-noble gas atom transparent conductive layer (43) is placed on one side in the thickness direction of the transparent conductive layer (3).

[0167] Also, as mentioned above, since a second noble gas is used as a sputtering gas, a second noble gas atom originating from the second noble gas is introduced into a transparent conductive layer (43) that does not contain a first noble gas atom.

[0168] Thus, a transparent conductive layer (43) that does not contain a first noble gas atom is obtained, and a transparent conductive sheet (1) having a substrate layer (2), a transparent conductive layer (3), and a transparent conductive layer (43) that does not contain a first noble gas atom is obtained in order.

[0169] Also, in FIG. 8, the transparent conductive sheet (1) is provided with a substrate layer (2), a transparent conductive layer (3), and a first transparent conductive layer (43) that does not contain noble gas atoms in order toward one side in the thickness direction. Meanwhile, although not shown, the transparent conductive sheet (1) may be provided with a substrate layer (2), a first transparent conductive layer (43) that does not contain noble gas atoms, and a transparent conductive layer (3) in order toward one side in the thickness direction.

[0170] In the above description, the case where the functional layer (42) is a hard coat layer was described, but the functional layer (42) may also be an optical adjustment layer.

[0171] The optical adjustment layer is a layer that adjusts the optical properties (e.g., refractive index) of the transparent conductive sheet (1) in order to suppress pattern visibility of the transparent conductive layer (3) or suppress reflection at the interface within the transparent conductive sheet (1) while ensuring excellent transparency of the transparent conductive sheet (1).

[0172] The optical adjustment layer is formed, for example, from an optical adjustment composition.

[0173] The optical adjustment composition contains, for example, a resin and particles. Examples of resins include the resins exemplified in the hard coat composition. Examples of particles include the particles exemplified in the hard coat composition. The optical adjustment composition may be a resin alone or an inorganic alone. Examples of resins exemplified in the hard coat composition. In addition, examples of inorganic materials include metalloid oxides and / or metal oxides such as silicon oxide, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. It is not necessary to specify whether the metalloid oxides and / or metal oxides are stoichiometric in composition.

[0174] The thickness of the optical adjustment layer is, for example, 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and also, for example, 200 nm or less, preferably 100 nm or less. The thickness of the optical adjustment layer can be calculated, for example, based on the wavelength of the interference spectrum observed using an instantaneous multiphotometric system. In addition, the thickness may be determined by observing the cross-section of the optical adjustment layer using FE-TEM.

[0175] Also, as a functional layer (42), a hard coat layer and an optical adjustment layer may be used in combination (a multilayer including a hard coat layer and an optical adjustment layer).

[0176] Also, in the above description, the substrate layer (2) is provided with a transparent substrate (41) and a functional layer (42) in sequence facing one side in the thickness direction. However, the substrate layer (2) may be made of a transparent substrate (41) without a functional layer (42).

[0177] Also, in the above description, the transparent conductive layer (3) contains a material and a first noble gas atom, but may also contain a second noble gas atom together with these.

[0178] In the case where the transparent conductive layer (3) contains a second noble gas atom, the second noble gas is used together with the first noble gas as a sputtering gas in the second process.

[0179] Thus, along with the first noble gas atoms originating from the first noble gas, the second noble gas atoms originating from the second noble gas are introduced into the transparent conductive layer (3).

[0180] The content of the second noble gas atom is, specifically, 2.0 atomic% or less, preferably 1.0 atomic% or less, more preferably 0.7 atomic% or less, particularly preferably 0.5 atomic% or less, most preferably 0.3 atomic% or less, furthermore 0.2 atomic% or less, and for example, 0.0001 atomic% or more.

[0181] As described above, the transparent conductive layer (3) may contain a second noble gas atom, but preferably, the transparent conductive layer (3) does not contain a second noble gas atom. In short, preferably, the transparent conductive layer (3) is composed of a material and a first noble gas atom.

[0182] Examples

[0183] The present invention will be explained more specifically below by presenting examples and comparative examples. Furthermore, the present invention is not limited in any way to examples and comparative examples. Also, specific numerical values ​​such as mixing ratios (content ratios), physical property values, and parameters used in the description below may be replaced with the upper limit (a numerical value defined as “less than” or “less than”) or lower limit (a numerical value defined as “greater than” or “greater than”) of the corresponding mixing ratios (content ratios), physical property values, parameters, etc. described in the “forms for carrying out the invention” above.

[0184] 1. Manufacture of transparent conductive layer and transparent conductive sheet

[0185] Example 1

[0186] <Process 1>

[0187] A hard coat composition (UV-curable resin containing acrylic resin) was applied to one side in the thickness direction of a long PET film (thickness 50 μm, manufactured by Toray Corporation) used as a transparent substrate to form a coating film. Next, the coating film was cured by UV irradiation. In this way, a hard coat layer (thickness 2 μm) was formed. By this, a substrate layer was prepared.

[0188] <Process 2>

[0189] Next, an amorphous transparent conductive layer with a thickness of 150 nm was deposited on one side in the thickness direction of the substrate layer (hard coat layer) by reactive sputtering. In the reactive sputtering method, a sputtering device (DC magnetron sputtering device) capable of performing a film deposition process in a roll-to-roll manner was used.

[0190] Specifically, a sintered body of indium oxide and tin oxide (tin oxide concentration of 10 mass%) was used as the target. A DC power source was used to apply voltage to the target. The horizontal magnetic field strength on the target was set to 90 mT. In the sputtering apparatus, the substrate layer was adhered along the circumferential direction of the deposition roll. The temperature of the deposition roll (temperature of the substrate layer) was set to -8 ℃. In addition, the achievable vacuum level in the deposition chamber equipped with the sputter deposition apparatus was 0.8 × 10⁻⁶ -4 After vacuuming the sputtering apparatus until Pa was reached, krypton as a sputtering gas and oxygen as a reactive gas were introduced into the apparatus, and the atmospheric pressure inside the apparatus was set to 0.2 Pa. The ratio of the amount of oxygen introduced to the total amount of krypton and oxygen introduced into the sputtering apparatus was approximately 2.5 flow%. As shown in Fig. 4, the amount of oxygen introduced falls within region X of the resistivity-oxygen introduction curve, where the resistivity of the amorphous transparent conductive layer is 6.5 × 10⁻⁶. -4 The resistivity-oxygen introduction curve shown in Fig. 4 can be prepared by first investigating the dependence of the resistivity of an amorphous transparent conductive layer on the amount of oxygen introduced when the amorphous transparent conductive layer is formed by reactive sputtering under conditions other than the amount of oxygen introduced.

[0191] <Process 3>

[0192] An amorphous transparent conductive layer was crystallized by heating in a hot air oven. The heating temperature was set to 165°C, and the heating time was set to 1 hour.

[0193] Thus, a transparent conductive sheet was obtained having a substrate layer and a transparent conductive layer in sequence, together with a transparent conductive layer.

[0194] Example 2

[0195] A transparent conductive layer and a transparent conductive sheet were prepared in the same order as in Example 1.

[0196] However, the second process was modified as follows.

[0197] <Process 2>

[0198] By reactive sputtering, an amorphous transparent conductive layer with a thickness of 50 nm was deposited on one side in the thickness direction of the substrate layer (hard coat layer). In the reactive sputtering method, a sputtering deposition apparatus (DC magnetron sputtering apparatus) capable of performing a film deposition process in a roll-to-roll manner was used.

[0199] Specifically, a sintered body of indium oxide and tin oxide (tin oxide concentration of 10 mass%) was used as the target. A DC power source was used to apply voltage to the target. The horizontal magnetic field strength on the target was set to 90 mT. The film deposition temperature was set to -5 ℃. In addition, the achievable vacuum level in the film deposition chamber equipped with the sputter film deposition apparatus was 0.8 × 10⁻⁶ -4 After vacuuming the inside of the sputtering film deposition apparatus until Pa was reached, krypton as a sputtering gas and oxygen as a reactive gas were introduced into the apparatus, and the atmospheric pressure inside the apparatus was set to 0.2 Pa. The amount of oxygen introduced into the deposition chamber was such that the resistivity of the formed film was 6.5 × 10⁻⁶ -4 It was adjusted to Ω·cm.

[0200] Next, by reactive sputtering, a first amorphous transparent conductive layer (43) with a thickness of 80 nm, which does not contain noble gas atoms, was placed on one side in the thickness direction of the transparent conductive layer.

[0201] The conditions of the reactive sputtering method are the same as the conditions when an amorphous transparent conductive layer is placed on one side in the thickness direction of the substrate layer (hard coat layer) by the reactive sputtering method described above.

[0202] However, the sputtering gas was changed to argon gas. In addition, after introducing oxygen as a reactive gas with the sputtering gas, the pressure inside the film deposition chamber was changed to 0.4 Pa.

[0203] Thus, a transparent conductive sheet was obtained having, in order, a substrate layer, a transparent conductive layer (thickness 50 nm), and a first transparent conductive layer (thickness 80 nm) that does not contain noble gas atoms, together with a transparent conductive layer.

[0204] Example 3

[0205] A transparent conductive sheet was obtained together with a transparent conductive layer using the same method as in Example 1.

[0206] However, in the second process, the sputtering gas was changed to a mixed gas of krypton and argon (90 volume% krypton, 10 volume% argon).

[0207] Comparative Example 1

[0208] A transparent conductive sheet was obtained together with a transparent conductive layer using the same method as in Example 1.

[0209] However, in the second process, the sputtering gas was changed to argon gas. In addition, in the second process, after introducing oxygen as a reactive gas with the sputtering gas, the pressure inside the film deposition chamber was changed to 0.4 Pa.

[0210] Comparative Example 2

[0211] A transparent conductive sheet was obtained together with a transparent conductive layer using the same method as in Example 1.

[0212] However, in the second process, the pressure inside the film deposition chamber was changed to 0.4 Pa after introducing the sputtering gas and oxygen as a reactive gas. In addition, in the third process, the temperature of the film deposition roll (temperature of the substrate layer) was changed to 50 ℃. In addition, the thickness of the transparent conductive layer was changed to 30 nm.

[0213] 2. Evaluation

[0214] [Thickness of transparent conductive layer]

[0215] The thickness of the transparent conductive layer in Example 1, Example 3, and Comparative Examples 1 and 2 was measured by FE-TEM observation (cross-sectional observation). Specifically, first, samples for cross-sectional observation of the transparent conductive layer in Example 1 and Comparative Examples 1 and 2 were prepared by the FIB microsampling method. For the FIB microsampling method, a FIB device (product name "FB2200", manufactured by Hitachi) was used, and the acceleration voltage was set to 10 kV. Next, the thickness of the transparent conductive layer in the cross-sectional observation samples was measured by FE-TEM observation. For the FE-TEM observation, a FE-TEM device (product name "JEM-2800", manufactured by JEOL) was used, and the acceleration voltage was set to 200 kV. The respective thicknesses are shown in Table 1.

[0216] In Example 2, the thickness of the transparent conductive layer was determined by preparing a cross-sectional observation sample from an intermediate product before placing the first noble gas atom-free transparent conductive layer on one side in the thickness direction of the transparent conductive layer. Then, this cross-sectional observation sample was measured by FE-TEM observation. In this way, the thickness of the transparent conductive layer was determined. Additionally, the thickness of the first noble gas atom-free transparent conductive layer was determined by measuring the total thickness of the transparent conductive layer and the first noble gas atom-free transparent conductive layer by FE-TEM observation, and subtracting the thickness of the transparent conductive layer from the total thickness.

[0217] [Confirmation of Krypton Atoms in Transparent Conductive Layer]

[0218] The fact that the transparent conductive layer in Examples 1, 2, 3 and Comparative Example 2 contains krypton atoms was confirmed as follows. First, using a scanning fluorescence X-ray analyzer (product name "ZSX Primus IV", manufactured by Rigaku Co., Ltd.), fluorescence X-ray analysis measurements were repeated five times under the following measurement conditions, and the average value of each scanning angle was calculated to create an X-ray spectrum. Then, by confirming that a peak appeared near a scanning angle of 28.2° in the created X-ray spectrum, it was confirmed that the transparent conductive layer contains krypton atoms.

[0219] <Measurement Conditions>

[0220] Spectrum ; Kr-KA

[0221] Measured diameter: 30 mm

[0222] Atmosphere: Vacuum

[0223] Target: Rh

[0224] Tube voltage: 50 kV

[0225] Tube current: 60 mA

[0226] Primary filter: Ni40

[0227] Scan angle (deg): 27.0 ~ 29.5

[0228] Step (deg): 0.020

[0229] Speed ​​(deg / min): 0.75

[0230] Attenuator : 1 / 1

[0231] Slit : S2

[0232] Spectroscopic crystal: LiF (200)

[0233] Detector: SC

[0234] PHA : 100 ∼ 300

[0235] [Confirmation of Argon Atoms in Transparent Conductive Layer]

[0236] By Rutherford backscatter spectroscopy (RBS), it was confirmed that argon atoms were contained in the first noble gas atom-free transparent conductive layer of Examples 2 and 3, and in the transparent conductive layer of Comparative Example 1. More specifically, four elements—In + Sn (since it is difficult to measure In and Sn separately in Rutherford backscatter spectroscopy, they were evaluated as the sum of the two elements), O, and Ar—were measured as detection elements to confirm the presence of argon atoms in the transparent conductive layer. The apparatus used and measurement conditions are as follows.

[0237] <Usage Device>

[0238] Pelletron 3SDH (manufactured by National Electrostatics Corporation)

[0239] <Measurement Conditions>

[0240] Incident ion: 4He ++

[0241] Incident energy: 2300 keV

[0242] Angle of incidence: 0 deg

[0243] Scattering angle: 160 degrees

[0244] Sample current: 6 nA

[0245] Beam diameter: 2 mmφ

[0246] In-plane rotation: None

[0247] Irradiation dose: 75 μC

[0248] [Presence or absence of first grain boundary, second grain boundary, and first crystal grain]

[0249] After cross-sectionally adjusting the transparent conductive sheets of each example and each comparative example using the FIB microsampling method, FE-TEM observation was performed on the cross-section of each transparent conductive layer to observe the presence or absence of the first grain boundary, the second grain boundary, and the first crystal grain. In addition, the magnification was set so that a specific crystal grain could be observed. The presence or absence of the first grain boundary, the second grain boundary, and the first crystal grain is shown in Table 1.

[0250] In addition, in Example 1, Example 2 and Comparative Example 1, a second grain, a third grain, and a fourth grain were observed along with a first grain boundary, a second grain boundary, and a first grain.

[0251] The device and measurement conditions are as follows.

[0252] FIB device; Hitachi FB2200, acceleration voltage: 10 kV

[0253] FE-TEM device: JEM-2800 manufactured by JEOL, acceleration voltage: 200 kV

[0254] [Resistivity]

[0255] The surface resistance of the transparent conductive layer of each example and each comparative example was measured at four terminals. The resistivity value was calculated by multiplying the obtained surface resistance by the thickness of the transparent conductive layer. The resistivity values ​​were evaluated based on the following criteria. The results are shown in Table 1.

[0256] ○ : Resistivity is 1.6×10 -4 It was less than Ω·cm.

[0257] △ : Resistivity is 1.7×10 -4 Ω·cm or greater, 2.2×10⁻⁶ -4 It was less than Ω·cm.

[0258] × : Resistivity is 2.2×10 -4 It exceeded Ω·cm.

[0259] [Etching rate of transparent conductive layer]

[0260] A transparent conductive sheet of each example and comparative example was immersed in hydrochloric acid at a concentration of 7 mass% and 35°C, then washed and dried, and the resistance between terminals over a distance of 15 mm was measured using a tester (the measurement cycle by the tester was set to every 15 seconds). In this specification, the time when the resistance between terminals over a distance of 15 mm exceeded 50 kΩ or was insulated after immersion, washing, and drying in hydrochloric acid was set as the time when the etching of the transparent conductive layer (3) was completed, and the time required to etch the transparent conductive layer by 1 nm (etching rate (seconds / nm)) was calculated by dividing that time by the total thickness of the transparent conductive layer, and an evaluation was performed according to the following criteria.

[0261] ○ : The etching time per unit thickness was 12 (sec / nm) or more to 20 (sec / nm) or less.

[0262] △ : The etching time per unit thickness was less than 12 (sec / nm).

[0263] × : The etching time per unit thickness was greater than 20 (sec / nm).

[0264]

[0265] Furthermore, although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be interpreted restrictively. Variations of the present invention that are obvious to those skilled in the art are included in the claims set forth below.

[0266] Industrial applicability

[0267] The transparent conductive layer and transparent conductive sheet of the present invention are preferably used, for example, in an electromagnetic shielding member, a heating wire control member, a heater member, a lighting member, an antenna member, a touch sensor device, and an image display device. Explanation of the symbols

[0268] 1 : Transparent conductive sheet 2 : Base layer 3: Transparent conductive layer 4 : Grain 5: The first week 6: The second week 8: Second grain boundary 9: Single edge 25 : Intermediate area 31: First crystal grain 55 : Side 56 : One side

Claims

Claim 1 A transparent conductive layer having a first main surface and a second main surface facing the first main surface in the thickness direction, a grain boundary in which both end edges are open to the first main surface when viewed in cross-section and an intermediate region between the two end edges does not contact the second main surface, and a first crystal grain separated by the grain boundary and facing only the first main surface, containing noble gas atoms having an atomic number greater than that of argon atoms, and having a thickness of less than 300 nm. Claim 2 A transparent conductive layer according to claim 1, comprising a region that is a single layer extending in a plane direction orthogonal to the thickness direction. Claim 3 A transparent conductive layer according to claim 1, further characterized by having a second grain boundary that is open on the side connecting the end edge of the first main surface and the end edge of the second main surface. Claim 4 A transparent conductive layer according to claim 1, wherein the material of the transparent conductive layer is a tin-containing oxide. Claim 5 A transparent conductive sheet comprising a transparent conductive layer described in any one of claims 1 to 4 and a substrate layer located on the second main side of the transparent conductive layer.

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