Light-transmitting conductive sheet

Abstract

To provide an optically transparent conductive sheet that offers low resistivity while exhibiting superior bendability.SOLUTION: An optically transparent conductive sheet 1 includes a substrate layer 2 and an optically transparent conductive layer 3, which are sequentially provided toward one side in the thickness direction. The optically transparent conductive layer 3 includes a first region 31 and a second region 32, sequentially provided toward one side in the thickness direction. The main domain of the first region 31 is crystalline and the main domain of the second region 32 is amorphous.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a light-transmitting conductive sheet. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a light-transmitting conductive sheet is known which includes a substrate and a light-transmitting conductive layer in that order. Such a light-transmitting conductive sheet is suitably used in various devices (for example, a touch sensor).

[0003] As such a light-transmitting conductive sheet, for example, a light-transmitting conductive sheet has been proposed which includes a resin layer and a light-transmitting conductive layer, in that order, toward one side in the thickness direction, and the light-transmitting conductive layer includes a first region which is amorphous and a second region which is crystalline, in that order, toward one side in the thickness direction (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 241118 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, the light-transmitting conductive layer is required to have a lower resistivity. In order to reduce the resistivity, it has been considered to increase the thickness of the light-transmitting conductive layer, but when the thickness of the light-transmitting conductive layer is increased, there is a problem that the flexibility is reduced.

[0006] The present invention provides a light-transmitting conductive sheet that has low resistivity and excellent flexibility. [Means for solving the problem]

[0007] The present invention [1] is a light-transmitting conductive sheet comprising a base layer and a light-transmitting conductive layer, in that order toward one side in a thickness direction, the light-transmitting conductive layer comprising a first region and a second region, in that order toward one side in the thickness direction, a main region of the first region being crystalline, and a main region of the second region being amorphous.

[0008] The present invention [2] includes the optically transparent conductive sheet according to the above [1], wherein the second region has a thickness greater than the thickness of the first region. Effect of the Invention

[0009] The light-transmitting conductive sheet of the present invention includes a base layer and a light-transmitting conductive layer, which are arranged in this order toward one side in the thickness direction. In addition, in this light-transmitting conductive sheet, the light-transmitting conductive layer includes a first region whose main region is crystalline and a second region whose main region is amorphous, which are arranged in this order toward one side in the thickness direction. Therefore, the sheet has low resistivity and excellent flexibility. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 shows one embodiment of the light-transmitting conductive sheet of the present invention. [Diagram 2] 2A to 2D show one embodiment of a method for producing a light-transmitting conductive sheet. FIG. 2A shows a first step of preparing a substrate. FIG. 2B shows a first step of arranging a cured resin layer on one surface in the thickness direction of the substrate. FIG. 2C shows a third step of arranging a first region on one surface in the thickness direction of the substrate layer. FIG. 2D shows a fourth step of arranging a second region on one surface in the thickness direction of the first region in the second step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] One embodiment of the light-transmitting conductive sheet of the present invention will be described with reference to FIG.

[0012] In FIG. 1, the up-down direction of the paper is the up-down direction (thickness direction). The upper side of the paper is the top side (one side in the thickness direction). The lower side of the paper is the bottom side (the other side in the thickness direction). The left-right direction and the depth direction of the paper are surface directions perpendicular to the up-down direction. Specifically, they follow the directional arrows in each figure.

[0013] The light-transmitting conductive sheet 1 has a film shape (including a sheet shape) having a predetermined thickness. The light-transmitting conductive sheet 1 extends in a plane direction perpendicular to the thickness direction. The light-transmitting conductive sheet 1 has a flat upper surface and a flat lower surface. The light-transmitting conductive sheet 1 is preferably flexible.

[0014] 1, the light-transmitting conductive sheet 1 includes a base layer 2 and a light-transmitting conductive layer 3 disposed on one side in the thickness direction of the base layer 2. Specifically, the light-transmitting conductive sheet 1 includes a base layer 2 and a light-transmitting conductive layer 3 disposed directly on the upper surface (one side in the thickness direction) of the base layer 2. The light-transmitting conductive sheet 1 preferably includes the base layer 2 and the light-transmitting conductive layer 3.

[0015] The light-transmitting conductive sheet 1 has a thickness of, for example, 400 μm or less, preferably 200 μm or less, and for example, 1 μm or more, preferably 5 μm or more.

[0016] <Base material layer> The base material layer 2 has a film shape. The base material layer 2 is preferably flexible. The base material layer 2 is disposed on the entire lower surface of the light-transmitting conductive layer 3 so as to contact the lower surface of the light-transmitting conductive layer 3. The base material layer 2 is the bottom layer of the light-transmitting conductive sheet 1.

[0017] The substrate layer 2 includes a substrate 11 and a cured resin layer 12 disposed on one side of the substrate 11 in the thickness direction.

[0018] [Base material] The substrate 11 is disposed over the entire lower surface of the cured resin layer 12 so as to be in contact with the lower surface of the cured resin layer 12. The substrate 11 is the bottom layer of the light-transmitting conductive sheet 1.

[0019] Examples of the substrate 11 include a polymer film and glass. From the viewpoint of flexibility, the substrate 11 is preferably a polymer film.

[0020] Examples of materials for the polymer film include polyester resin, (meth)acrylic resin, olefin resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, and polystyrene resin. Examples of polyester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of (meth)acrylic resin include polymethyl methacrylate. Examples of olefin resin include polyethylene, polypropylene, and cycloolefin polymer. Examples of cellulose resin include triacetyl cellulose.

[0021] As the material of the polymer film, preferably, a polyester resin is used, and more preferably, polyethylene terephthalate is used.

[0022] The thickness of the substrate 11 is, for example, 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and for example, 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less.

[0023] The thickness of the substrate 11 can be measured using a dial gauge (manufactured by PEACOCK, "DG-205").

[0024] Moreover, the substrate 11 preferably has transparency. Specifically, the total light transmittance (JIS K 7375-2008) of the substrate layer 2 is, for example, 80% or more, or preferably 85% or more.

[0025] [Cured resin layer] The cured resin layer 12 is disposed over the entire lower surface of the light-transmitting conductive layer 3 so as to be in contact with the lower surface of the light-transmitting conductive layer 3 .

[0026] A dielectric layer can be used as the cured resin layer 12. In the following description, a case in which the cured resin layer 12 is a dielectric layer will be described in detail.

[0027] The dielectric layer is a layer for providing insulation between the substrate 11 and the light-transmitting conductive layer 3 .

[0028] The dielectric layer may be a cured product of a dielectric layer composition (for example, a melamine resin, an alkyd resin, or an organic silane condensate).

[0029] The dielectric layer has a thickness of, for example, 10 nm or more, preferably 30 nm or more, and for example, 100 nm or less, preferably 50 nm or less.

[0030] The dielectric layer, which will be described in detail later, is formed by applying a dielectric layer composition to one surface in the thickness direction of the substrate 11, and drying and curing it as necessary.

[0031] <Light-transparent conductive layer> The light-transmitting conductive layer 3 has a film shape. The light-transmitting conductive layer 3 is disposed over the entire upper surface of the base material layer 2 so as to be in contact with the upper surface of the base material layer 2. The light-transmitting conductive layer 3 is the uppermost layer of the light-transmitting conductive sheet 1.

[0032] Examples of materials for the light-transmitting conductive layer 3 include conductive oxides. Examples of conductive oxides include metal oxides containing at least one metal or metalloid selected from the group consisting of In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, and W. If necessary, the metal oxide may be doped with a metal atom or metalloid atom shown in the above group.

[0033] Examples of the conductive oxide include metal oxides, such as indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium gallium oxide (IGO), indium tin oxide (ITO), and antimony tin oxide (ATO).

[0034] From the viewpoint of improving transparency and electrical conductivity, the conductive oxide is preferably indium tin oxide (ITO). In the following description, the case where the material of the light-transmitting conductive layer 3 is indium tin oxide (ITO) will be described in detail.

[0035] In indium tin composite oxide (ITO), the concentration of tin oxide is, for example, 0.1 mass % or more, preferably 1 mass % or more, for example, 30 mass % or less.

[0036] The light-transmitting conductive layer 3 includes a first region 21 and a second region 22 arranged in this order toward one side in the thickness direction.

[0037] [First area] The first region 21 is the other thickness-wise side portion of the light-transmitting conductive layer 3. The first region 21 includes the other thickness-wise surface of the light-transmitting conductive layer 3. The first region 21 is formed across the entire surface of the light-transmitting conductive layer 3.

[0038] The main region of the first region 21 is crystalline. More specifically, the first region 21 includes a region that is crystalline as a main region in a cross-sectional view. Specifically, examples of the form of such a first region 21 include a form in which all the regions in the first region 21 are crystalline in a cross-sectional view, and a form in which the main region of the first region 21 is crystalline and the remaining small region is amorphous in a cross-sectional view.

[0039] The crystallinity of the first region 21 is confirmed by observing a cross-sectional TEM image. In addition, by observing the presence or absence of lattice fringes and the proportion of the region in which lattice fringes are confirmed by high-magnification cross-sectional TEM observation, it is possible to identify that the first region 21 is crystalline and / or that the region is mainly crystalline. In addition, when the first region 21 is crystalline, for example, the first region 21 is immersed in a 5% by mass hydrochloric acid aqueous solution for 15 minutes, washed with water and dried, and the two-terminal resistance is measured over a distance of about 15 mm on the surface of the first region 21, and the two-terminal resistance is 10 kΩ or less.

[0040] In addition, in a cross-sectional view, the area ratio of the main region in the first region 21 (the area ratio of the crystalline material) is, for example, 0.7 or more, preferably 0.8 or more, more preferably 0.9 or more, and is, for example, 1 or less.

[0041] The thickness of the first region 21 is preferably thinner than the thickness of the second region 22 described later, and is, for example, 1 nm or more, preferably 10 nm or more, more preferably 20 nm or more, and for example, 70 nm or less, preferably 50 nm or less, more preferably 30 nm or less.

[0042] The ratio of the thickness of the first region 21 to the thickness of the light-transmitting conductive layer 3 is, for example, 0.10 or more, preferably 0.15 or more, and for example, 0.40 or less, preferably 0.20 or less, more preferably 0.17 or less.

[0043] If the ratio is within the above range, it is possible to improve the flexibility while maintaining a low resistivity.

[0044] The method for measuring the thickness of the first region 21 will be described in detail in the examples described later.

[0045] The first region 21 includes a third region 31 and a fourth region 32 arranged in this order toward one side in the thickness direction. The third region 31 and the fourth region 32 are formed over the entire surface of the light-transmitting conductive layer 3.

[0046] The third region 31 and the fourth region 32 differ from each other in, for example, the ratio of the amount of tin oxide to the total amount of indium oxide (In2O3) and tin oxide (SnO2) in ITO (tin oxide content ratio). From the viewpoint of reducing resistance, the tin oxide content ratio of the third region 31 is preferably higher than the tin oxide content ratio of the fourth region 32.

[0047] The tin oxide content in the third region 31 is, for example, 5 mass% or more, preferably 7 mass% or more, more preferably 9 mass% or more, and for example, 15 mass% or less, preferably 12 mass% or less. The tin oxide content in the fourth region 32 is, for example, 1 mass% or more, preferably 2 mass% or more, and for example, less than 5 mass%, preferably 4 mass% or less.

[0048] The third region 31 has a thickness of, for example, 0.5 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and for example, 35 nm or less, preferably 25 nm or less, more preferably 15 nm or less.

[0049] The proportion of the thickness of the third region 31 to the thickness of the first region 21 is, for example, 20% or more, preferably 40% or more, and for example, 80% or less, preferably 60% or less.

[0050] The thickness of the fourth region 32 is, for example, 0.5 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and for example, 35 nm or less, preferably 25 nm or less, more preferably 15 nm or less.

[0051] The proportion of the thickness of the fourth region 32 to the thickness of the first region 21 is, for example, 20% or more, preferably 40% or more, and for example, 80% or less, preferably 60% or less.

[0052] [Second area] The second region 22 is a portion on one side in the thickness direction of the light-transmitting conductive layer 3. The second region 22 includes one surface in the thickness direction of the light-transmitting conductive layer 3. The second region 22 is continuous with one side in the thickness direction of the first region 21. The second region 22 is formed across the entire surface of the light-transmitting conductive layer 3.

[0053] The main region of the second region 22 is amorphous. Specifically, the second region 22 includes a region that is amorphous as a main region in a cross-sectional view. Specifically, examples of the form of the second region 22 include a form in which all the regions in the second region 22 are amorphous in a cross-sectional view, and a form in which the main region of the second region 22 is amorphous and the remaining small region is crystalline in a cross-sectional view.

[0054] The amorphous nature of the second region 22 is confirmed by observing a cross-sectional TEM image. In addition, by observing the presence or absence of lattice fringes and the proportion of the region in which lattice fringes are confirmed by high-magnification cross-sectional TEM observation, it is possible to identify that the second region 22 is amorphous and / or that the region is mainly amorphous. In addition, when the second region 22 is amorphous, for example, the second region 22 is immersed in a 5% by mass hydrochloric acid aqueous solution for 15 minutes, washed with water and dried, and the two-terminal resistance is measured over a distance of about 15 mm on the surface of the second region 22, and the two-terminal resistance exceeds 10 kΩ.

[0055] In addition, in a cross-sectional view, the area ratio of the main region in the second region 22 (amorphous area ratio) is, for example, 0.6 or more, preferably 0.8 or more, more preferably 0.9 or more, and is, for example, 1 or less.

[0056] From the viewpoint of flexibility, the thickness of the second region 22 is preferably thicker than the thickness of the first region 21, for example, more than 70 nm, preferably 80 nm or more, more preferably 90 nm or more, and even more preferably 100 nm or more, and from the viewpoint of low resistivity, for example, 150 nm or less, preferably 110 nm or less.

[0057] The ratio of the thickness of the second region 22 to the thickness of the light-transmitting conductive layer 3 is, for example, 0.60 or more, preferably 0.80 or more, more preferably 0.83 or more, and for example, 0.90 or less, preferably 0.85 or less.

[0058] If the ratio is within the above range, it is possible to improve the flexibility while maintaining a low resistivity.

[0059] The method for measuring the thickness of the second region 22 will be described in detail in the examples described below.

[0060] If the thickness of the second region 22 is greater than the thickness of the first region, the flexibility can be further improved.

[0061] The ratio of the thickness of the second region 22 to the thickness of the first region 21 is, for example, more than 1, preferably 2.0 or more, more preferably 4.0 or more, even more preferably 4.5 or more, and for example, 150 or less, preferably 100 or less, more preferably 10 or less, even more preferably 5.0 or less.

[0062] If the ratio is within the above range, it is possible to improve the flexibility while maintaining a low resistivity.

[0063] [Physical properties of light-transmitting conductive layer] The thickness of the light-transmitting conductive layer 3 is the sum of the first region 21 and the second region 22, and from the viewpoint of low resistance, is, for example, 100 nm or more, preferably 110 nm or more, more preferably 125 nm or more, and for example, 200 nm or less, preferably 150 nm or less.

[0064] The total light transmittance (JIS K 7375-2008) of the light transmissible conductive layer 3 is, for example, 60% or more, preferably 80% or more, more preferably 85% or more, and for example, 100% or less.

[0065] The surface resistance of the light-transmitting conductive layer 3 is, for example, 40 Ω / □ or less, preferably 35 Ω / □ or less, and for example, more than 0 Ω / □. The surface resistance can be measured by a four-terminal method in accordance with JIS K7194.

[0066] The resistivity of the light-transmitting conductive layer 3 is, for example, 2.8×10 -4 Ωcm or less, more preferably 2.5×10 -4 Ωcm or less, for example, greater than 0 Ωcm, preferably 0.1×10 -4 Ωcm or more, more preferably 1.0×10 -4 The resistivity is calculated by multiplying the surface resistance by the thickness.

[0067] <Method for producing light-transmitting conductive sheet> A method for producing the light-transmitting conductive sheet 1 will be described with reference to FIGS. 2A to 2D.

[0068] The method for producing the light-transmitting conductive sheet 1 includes a first step of preparing a base layer 2, and a second step of disposing a light-transmitting conductive layer 3 on one surface in the thickness direction of the base layer 2 by a sputtering method. In this method, each layer is disposed in order, for example, by a roll-to-roll method. In such a case, the conveying speed is, for example, 1.0 m / min or more and, for example, 20.0 m / min or less.

[0069] [1st step] In the first step, the base layer 2 is prepared.

[0070] To prepare the base layer 2, a base material 11 is prepared as shown in FIG. 2A.

[0071] Next, as shown in FIG. 2B, a cured resin layer 12 (dielectric layer) is disposed on one surface of the base material 11 in the thickness direction.

[0072] To dispose the cured resin layer 12 (dielectric layer) on one surface in the thickness direction of the substrate 11, a dielectric layer composition is applied to one surface in the thickness direction of the substrate 11, and dried and cured as necessary. In this way, the cured resin layer 12 (dielectric layer) is disposed on one surface in the thickness direction of the substrate 11, and the substrate layer 2 is prepared.

[0073] [Second process] In the second step, the light-transmitting conductive layer 3 is disposed on one surface of the base layer 2 in the thickness direction by sputtering.

[0074] Specifically, the second step includes a third step of arranging the first region 21 on one surface of the base layer 2 in the thickness direction, and a fourth step of arranging the second region 22 on one surface of the first region 21 in the thickness direction.

[0075] (3rd step) 2C, in the third step, the first region 21 is disposed by sputtering on one surface in the thickness direction of the base layer 2. Specifically, the third region 31 and the fourth region 32 are disposed in this order by sputtering on one surface in the thickness direction of the base layer 2, and then the third region 31 and the fourth region 32 are crystallized.

[0076] Before the third region 31 and the fourth region 32 are sequentially disposed on one surface in the thickness direction of the base layer 2 by a sputtering method, the one surface in the thickness direction of the base layer 2 is subjected to a surface treatment, if necessary.

[0077] Examples of the surface treatment include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, and saponification treatment.

[0078] Next, in the sputtering method, the material for the third region 31 and the material for the fourth region 32 are placed as targets in this order along the transport direction of the base material layer 2 in each of two vacuum chambers arranged along the transport direction of the base material layer 2. The targets are placed so as to face the base material layer 2. In the sputtering method, the base material layer 2 is in close contact with the film-forming roll along the circumferential direction.

[0079] Next, a sputtering gas is supplied and a voltage is applied from a power source to accelerate the gas ions and irradiate the target, thereby ejecting the target material from the target surface. The target material is then deposited on the surface (one surface in the thickness direction) of the base layer 2, and the third region 31 and the fourth region 32 are arranged in this order.

[0080] Examples of the sputtering gas include an inert gas (e.g., krypton gas, argon gas) and oxygen gas. As the sputtering gas, preferably, an inert gas and an oxygen gas are used in combination. As the inert gas, preferably, krypton gas is used. When krypton gas is used as the inert gas, the first region 21 (the third region 31 and the fourth region 32) contains krypton atoms.

[0081] The amount of oxygen gas introduced is, for example, 1.0 flow % or more, preferably 1.5 flow % or more, and for example, 5.0 flow % or less, preferably 2.0 flow % or less, based on the total amount of inert gas and oxygen gas.

[0082] The pressure during sputtering is, for example, 0.1 Pa or more, preferably 0.2 Pa or more, and for example, 2.0 Pa or less.

[0083] The power source may be, for example, a DC power source, an AC power source, an MF power source, or an RF power source, or may be a combination of these.

[0084] The discharge output is, for example, 1.0 kW or more, preferably 10.0 kW or more, and for example, 20 kW or less.

[0085] The horizontal magnetic field strength of the target is, for example, 10 mT or more, preferably 60 mT or more, and for example, 200 mT or less, preferably 100 mT or less.

[0086] The temperature of the film-forming roll is, for example, 20° C. or lower, preferably 10° C. or lower, more preferably 0° C. or lower, and for example, −50° C. or higher, preferably −25° C. or higher.

[0087] Next, the third region 31 and the fourth region 32 are crystallized.

[0088] To crystallize the third region 31 and the fourth region 32, the third region 31 and the fourth region 32 are heated. Specifically, after sputtering, the third region 31 and the fourth region 32 are heated using a heating roll.

[0089] As for the heating conditions, the heating temperature is, for example, 120° C. or more, preferably 150° C. or more, and for example, 250° C. or less, preferably 200° C. or less; and the heating time is, for example, 30 seconds or more, and for example, 120 seconds or less.

[0090] As a result, the third region 31 and the fourth region 32 are crystallized to obtain the first region 21. In this manner, the first region 21 is disposed on one surface of the base layer 2 in the thickness direction.

[0091] (4th step) In a fourth step, as shown in FIG. 2D, the second region 22 is disposed on one surface of the first region 21 in the thickness direction by a sputtering method.

[0092] Next, in the sputtering method, a target (material of the second region 22) and the first region 21 are placed facing each other in a vacuum chamber. Next, sputtering gas is supplied and a voltage is applied from a power source to accelerate gas ions and irradiate the target, thereby ejecting the target material from the target surface. Then, the target material is deposited on the surface (one surface in the thickness direction) of the first region 21 to form the second region 22. In addition, in the sputtering, the base layer 2 is in close contact with the film-forming roll along the circumferential direction.

[0093] Examples of the sputtering gas include an inert gas (e.g., krypton gas, argon gas) and oxygen gas. The inert gas is preferably argon gas. When argon gas is used as the inert gas, the second region 22 contains argon atoms.

[0094] The amount of oxygen gas introduced is, for example, 0.05 flow % or more, preferably 0.1 flow % or more, and for example, 2.0 flow % or less, preferably 1.0 flow % or less, based on the total amount of inert gas and oxygen gas.

[0095] The pressure during sputtering is, for example, 0.1 Pa or more, preferably 0.2 Pa or more, and for example, 2.0 Pa or less.

[0096] The power source may be, for example, a DC power source, an AC power source, an MF power source, or an RF power source, or may be a combination of these.

[0097] The discharge output is, for example, 1.0 kW or more, preferably 10.0 kW or more, and for example, 20 kW or less.

[0098] The horizontal magnetic field strength of the target is, for example, 10 mT or more, and, for example, 200 mT or less, preferably 100 mT or less, and more preferably 40 mT or less.

[0099] The temperature of the film-forming roll is, for example, 20° C. or lower, preferably 10° C. or lower, more preferably 0° C. or lower, and for example, −50° C. or higher, preferably −25° C. or higher.

[0100] As a result, the second region 22 is disposed on one surface in the thickness direction of the first region 21. In this manner, the light-transmitting conductive sheet 1 is obtained.

[0101] <Action and effect> The light-transmitting conductive sheet 1 includes a base layer 2 and a light-transmitting conductive layer 3, which are arranged in this order toward one side in the thickness direction. In addition, in this light-transmitting conductive sheet 1, the light-transmitting conductive layer 3 includes a first region 21 whose main region is crystalline and a second region 22 whose main region is amorphous, which are arranged in this order toward one side in the thickness direction. Therefore, the sheet has excellent flexibility while having low resistivity.

[0102] More specifically, the light-transmitting conductive layer 3 is required to have a lower resistivity, but increasing the thickness of the light-transmitting conductive layer 3 from the viewpoint of lowering the resistivity causes a problem of reduced flexibility.

[0103] On the other hand, in this light transmissible conductive sheet 1, the first regions 21 and the second regions 22 are arranged in a predetermined order, and therefore the sheet has excellent flexibility while having low resistivity.

[0104] <Modification> In the modified example, the same reference numerals are used for the same components and steps as those in the first embodiment, and detailed descriptions thereof will be omitted. In addition, the modified example can achieve the same effects as those in the first embodiment, unless otherwise specified. Furthermore, the first embodiment and its modified example can be appropriately combined.

[0105] In the above description, the cured resin layer 12 is a dielectric layer, but the cured resin layer 12 may be a hard coat layer.

[0106] The hard coat layer is an abrasion protection layer for preventing the light-transmitting conductive layer 3 from being scratched.

[0107] An example of the hard coat layer is a cured product of a hard coat composition (such as an acrylic resin or a urethane resin) described in JP-A-2016-179686.

[0108] The hard coat layer is formed by applying a hard coat composition to one surface in the thickness direction of the substrate 11, and drying and curing the composition as necessary.

[0109] The thickness of the hard coat layer is, for example, 0.1 μm or more, preferably 0.5 μm or more, and for example, 10 μm or less, preferably 5 μm or less.

[0110] In the above description, the base layer 2 includes the base material 11 and the cured resin layer 12. However, the base layer 2 may include only the base material 11 without including the cured resin layer 12.

[0111] In the above description, the first region 21 includes the third region 31 and the fourth region 32 in order toward one side in the thickness direction, but the first region 21 may include only one of the third region 31 and the fourth region 32. Preferably, the first region 21 includes the third region 31 and the fourth region 32 in order toward one side in the thickness direction. EXAMPLES

[0112] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited to the examples and comparative examples. The specific numerical values ​​of the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numerical values ​​defined as "less than or equal to" or "less than") or lower limit values ​​(numerical values ​​defined as "more than or equal to" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention".

[0113] <Production of light-transmitting conductive sheet> Example 1 [1st step] A long PET film (thickness: 50 μm, manufactured by Toray Industries, Inc.) was prepared as a substrate.

[0114] Next, a dielectric layer composition (a thermosetting resin (refractive index of light n=1.54) of melamine resin: alkyd resin: organic silane condensate in a weight ratio of 2:2:1) was applied to one surface of the substrate in the thickness direction and cured to form a dielectric layer (thickness: 35 nm). Thus, the substrate layer was prepared.

[0115] [Second process] The first region was disposed on one surface of the base layer in the thickness direction by reactive sputtering. In the reactive sputtering, a sputtering deposition apparatus (DC magnetron sputtering apparatus) capable of performing a deposition process by a roll-to-roll method was used.

[0116] (3rd step) Specifically, first, an amorphous third region was disposed on one surface in the thickness direction of the base layer.

[0117] Specifically, a sintered body of indium oxide and tin oxide (tin oxide concentration: 10% by mass) was used as the target. A DC power supply was used as the power source for applying a voltage to the target. The horizontal magnetic field strength on the target was 90 mT. In the sputtering device, the base material layer was brought into close contact with the film-forming roll along the circumferential direction. The temperature of the film-forming roll was set to -5°C. The ultimate vacuum in the film-forming chamber of the sputtering film-forming device was 0.9 x 10 -4 After evacuating the inside of the sputtering deposition apparatus until the pressure reached 0.2 Pa, krypton as a sputtering gas and oxygen as a reactive gas were introduced into the sputtering deposition apparatus, and the pressure inside the sputtering deposition 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 deposition apparatus was approximately 1.8 flow %. As a result, an amorphous third region (11 nm) was disposed on one surface in the thickness direction of the base layer.

[0118] Next, an amorphous fourth region was disposed on one surface in the thickness direction of the third region.

[0119] Specifically, a sintered body of indium oxide and tin oxide (tin oxide concentration: 3% by mass) was used as the target. A DC power supply was used as the power supply for applying a voltage to the target. The horizontal magnetic field strength on the target was 90 mT. In the sputtering device, the base layer was adhered to the film-forming roll along the circumferential direction. The temperature of the film-forming roll was -5°C. Krypton as the sputtering gas and oxygen as the reactive gas were introduced, and the air pressure in the sputtering film-forming device was 0.2 Pa. The ratio of the amount of oxygen introduced to the total amount of krypton and oxygen introduced into the sputtering film-forming device was about 1.8 flow rate %. As a result, an amorphous fourth region (11 nm) was arranged on one surface in the thickness direction of the third region.

[0120] Next, the base layer having the third and fourth regions was brought into contact with a heating roll in a vacuum heating device. This caused the third and fourth regions to crystallize. The heating temperature was 160°C, and the heating time was 1 minute. This resulted in the first region being disposed on one surface in the thickness direction of the base layer.

[0121] (4th step) An amorphous second region was disposed on one surface in the thickness direction of the first region.

[0122] Specifically, a sintered body of indium oxide and tin oxide (tin oxide concentration: 12% by mass) was used as the target. A DC power supply was used as the power source for applying a voltage to the target. The horizontal magnetic field strength on the target was 30 mT. In the sputtering device, the base material layer was brought into close contact with the film-forming roll along the circumferential direction. The temperature of the film-forming roll was set to -5°C. The ultimate vacuum in the film-forming chamber of the sputtering film-forming device was 0.9×10 -4After evacuating the inside of the sputtering deposition apparatus until the pressure reached 0.2 Pa, argon as a sputtering gas and oxygen as a reactive gas were introduced into the sputtering deposition apparatus, and the pressure inside the sputtering deposition apparatus was set to 0.2 Pa. The ratio of the amount of oxygen introduced to the total amount of argon and oxygen introduced into the sputtering deposition apparatus was approximately 0.1 flow rate %. As a result, an amorphous second region (108 nm) was disposed on one surface in the thickness direction of the first region. In this manner, a light-transmitting conductive sheet was manufactured.

[0123] Example 2 A light-transmitting conductive sheet was produced according to the same procedure as in Example 1. However, the thickness of the second region was changed.

[0124] Comparative Example 1 A light-transmitting conductive sheet was manufactured based on the same procedure as in Example 1. However, the third step was not performed. In the fourth step, the ratio of the amount of oxygen introduced to the total amount of argon and oxygen introduced into the sputtering deposition device was set to about 2.4% by flow rate, and the thickness of the second region was changed.

[0125] Comparative Example 2 A light-transmitting conductive sheet was produced according to the same procedure as in Example 1, except that the fourth step was not carried out.

[0126] Comparative Example 3 A light-transmitting conductive sheet was manufactured according to the same procedure as in Example 1. However, in the third step, an amorphous third region (120 nm) and an amorphous fourth region (10 nm) were arranged in this order, and then crystallized. In addition, the fourth step was not performed.

[0127] Comparative Example 4 A light-transmitting conductive sheet was produced based on the same procedure as in Example 1. However, in the second step, the fourth step was carried out before the third step. In addition, the thicknesses of the first and second regions were changed based on the description in Table 1.

[0128] <Evaluation> [Thickness of light-transmitting conductive layer] The thickness of the light-transmitting conductive layer (each region) of each Example and Comparative Example was measured by FE-TEM observation. Specifically, first, a cross-sectional observation sample of the light-transmitting conductive layer of each Example and Comparative Example was prepared by FIB microsampling. In the FIB microsampling method, a FIB device (trade name "FB2200", manufactured by Hitachi) was used, and the acceleration voltage was set to 10 kV. Next, the thickness of the light-transmitting conductive layer in the cross-sectional observation sample was measured by FE-TEM observation. In the FE-TEM observation, a FE-TEM device (trade name "JEM-2800", manufactured by JEOL) was used, and the acceleration voltage was set to 200 kV.

[0129] The thickness of the fourth region was calculated by subtracting the thickness of the third region from the thickness of the first region (the sum of the thickness of the third region and the thickness of the fourth region). The thickness of the second region was calculated by subtracting the thickness of the first region from the total thickness of the light-transmitting conductive layer. The results are shown in Table 1.

[0130] [Resistance value] The resistance value (R0) of the light-transmitting conductive layer of each Example and Comparative Example was measured by the four-terminal method. The resistance value less than 50Ω was recorded as a real number, and the resistance value of 50Ω or more was recorded as 50Ω or more. The results are shown in Table 1.

[0131] [Flexibility] The light-transmitting conductive sheets of each Example and Comparative Example were evaluated for their flexibility. Specifically, the light-transmitting conductive sheets of each Example and Comparative Example were cut to a width of 10 mm and a length of 150 mm to prepare samples. Then, the samples were placed on the mandrel so that the light-transmitting conductive layer was on the outside and the other surface of the substrate in the thickness direction was in contact with the mandrel. Then, both ends of the light-transmitting conductive sheet in the longitudinal direction were fastened with clips, and a weight of 1000 g was attached to the center of the clips. That is, a load of 100 g / mm was applied downward relative to the width of the light-transmitting conductive sheet to fold the light-transmitting conductive sheet. This folded state was maintained for 10 seconds.

[0132] In this bent state, the bent portion was painted with a marker, and then the bent portion was released and the marker was observed under a microscope. In this test method, the diameter of the mandrel was changed from large to small in 1 mm increments, and the smallest diameter at which no cracks were observed under the microscope in the marker-painted portion was recorded in Table 1. The smaller this value, the better the bending resistance. The results are shown in Table 1.

[0133] In the above test, the mandrel diameter was changed from large to small in increments of 1 mm, and the sample was changed for each change. In other words, in the above test, each sample was bent once, and each time it was bent, a different sample (a different sample manufactured under the same conditions) was used.

[0134] [Table 1] [Explanation of symbols]

[0135] 1. Light-transmitting conductive sheet 2 Base material layer 31 First area 32 Second area

Claims

[Claim 1] A base layer and a light-transmitting conductive layer are provided in this order toward one side in a thickness direction, the light-transmitting conductive layer includes a first region and a second region in this order toward one side in a thickness direction, a major region of the first region is crystalline; a major portion of the second region is amorphous; a ratio of a thickness of the first region to a thickness of the light-transmitting conductive layer is 0.10 or more and 0.40 or less; a ratio of a thickness of the second region to a thickness of the light-transmitting conductive layer is 0.60 or more and 0.90 or less; The substrate layer is a light-transmitting conductive sheet having a substrate and a cured resin layer in that order toward one side in the thickness direction.

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