Conductive film for dimming

Abstract

The invention relates to a conductive film for dimming. A conductive film (1) for dimming is provided with a base material (2), a blackened layer (3), and an inorganic layer (4) in this order toward one side in the thickness direction, and the inorganic layer (4) is provided with a first transparent conductive layer (41), a metal layer (42), and a second transparent conductive layer (43) in this order toward one side in the thickness direction.

Description

Technical Field

[0001] The present invention relates to a conductive film for light adjustment. Background Art

[0002] Conventionally, a light-adjusting conductive film is known, comprising: a substrate; and an inorganic layer, wherein one surface of the substrate in the thickness direction includes a metal layer. Such light-adjusting conductive films are used in applications such as automobile sunroofs. From a design perspective, automobile sunroofs are preferably black. Therefore, light-adjusting conductive films for such applications are adjusted to have an appropriate transmittance for light in the visible light range.

[0003] As such a light-adjusting conductive film, a light-adjusting conductive film having a blackened layer disposed on one surface in the thickness direction of an inorganic layer (the surface of the substrate opposite to the inorganic layer) has been proposed (for example, see Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2019 / 163897 Pamphlet

[0007] Depending on the application, the conductive film for light control is required to have excellent reflectivity with respect to light in a high wavelength region from the viewpoint of heat shielding properties.

[0008] In this regard, increasing the thickness of the metal layer within the inorganic layer is being studied to adjust the transmittance of the light-adjusting conductive film in the visible light range. However, the increased thickness of the metal layer in such a light-adjusting conductive film excessively reduces its resistance, potentially causing short circuits.

[0009] On the other hand, the light-adjusting conductive film described in Patent Document 1 includes a blackened layer on one surface of the inorganic layer in the thickness direction. This allows for adjustment of the transmittance of light in the visible light range, but high-wavelength light is absorbed by the blackened layer before being reflected by the metal layer within the inorganic layer. As a result, sufficient reflectivity for high-wavelength light cannot be achieved, leading to a disadvantageous reduction in thermal insulation properties. Summary of the Invention

[0010] The present invention provides a conductive film for light control, which suppresses excessive reduction in resistance value, has excellent transmittance to light in the visible light region, and has excellent reflectance to light in the high wavelength region.

[0011] The present invention [1] includes a conductive film for light adjustment, wherein the film comprises, in order toward one side in the thickness direction: a substrate, a blackened layer, and an inorganic layer, and the inorganic layer comprises, in order toward one side in the thickness direction: a first transparent conductive layer, a metal layer, and a second transparent conductive layer.

[0012] The present invention [2] includes the light control conductive film described in [1], further comprising a metal oxide layer between the substrate and the blackening layer.

[0013] The present invention [3] includes the light-adjusting conductive film described in [2], wherein the metal oxide layer is an indium tin composite oxide layer.

[0014] The present invention [4] includes the conductive film for light control according to [2] or [3], wherein the thickness of the metal oxide layer is 1 nm or more and less than 40 nm.

[0015] The present invention [5] includes the light-adjusting conductive film according to any one of [1] to [4], wherein the first transparent conductive layer and the second transparent conductive layer are indium tin composite oxide layers, and the metal layer is a silver alloy layer.

[0016] The present invention [6] includes the conductive film for light control according to any one of [1] to [5], wherein the blackened layer contains a metal and a metal oxide.

[0017] The present invention [7] includes the conductive film for light control according to any one of [1] to [6], wherein the blackened layer contains copper, copper oxide, and indium oxide.

[0018] The present invention [8] includes the light control conductive film according to any one of [1] to [7], wherein the thickness of the blackened layer is 1 nm or more and less than 40 nm.

[0019] The present invention [9] includes the conductive film for light control according to any one of [1] to [8], wherein the film has a visible light transmittance of 30% to 80% and a resistance of 6Ω / □ to 15Ω / □.

[0020] The present invention

[10] comprises the conductive film for light control according to any one of [1] to [9], wherein the solar reflectance is 33% or more.

[0021] Effects of the Invention

[0022] The light-adjustable conductive film of the present invention comprises, in order along one side in the thickness direction, a substrate, a blackened layer, and an inorganic layer. The inorganic layer comprises, in order along one side in the thickness direction, a first transparent conductive layer, a metal layer, and a second transparent conductive layer. This suppresses excessive decreases in resistance, exhibits excellent transmittance for light in the visible light range, and exhibits excellent reflectance for light in the high-wavelength range. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A cross-sectional view showing a first embodiment of the light control conductive film of the present invention.

[0024] Figure 2 A cross-sectional view showing a second embodiment of the light control conductive film of the present invention.

[0025] Figure 3A 、 Figure 3B Indicates Figure 1 The present invention relates to a method for producing a light control conductive film with a protective film, in which a light control conductive film is laminated to a protective film. Figure 3A Indicates the process of preparing a substrate with a protective film. Figure 3B This step shows the process of forming a blackened layer and an inorganic layer on a substrate with a protective film.

[0026] Figures 4A to 4C Indicates Figure 2 The present invention relates to a method for producing a light control conductive film with a protective film, in which a light control conductive film is laminated to a protective film. Figure 4A Indicates the process of preparing a substrate with a protective film. Figure 4B It represents the process of forming a metal oxide layer on a substrate with a protective film. Figure 4C This shows the process of forming a blackened layer and an inorganic layer on the metal oxide layer.

[0027] Description of Reference Numerals

[0028] 1: conductive film for light adjustment; 2: substrate; 3: blackened layer; 4: inorganic layer; 41: first transparent conductive layer; 42: metal layer; 43: second transparent conductive layer. DETAILED DESCRIPTION

[0029] 1. First Implementation

[0030] Reference Figure 1 , a first embodiment of the light control conductive film of the present invention is described.

[0031] The light-adjusting conductive film 1 is in the form of a film (including a sheet) having a predetermined thickness. Furthermore, the light-adjusting conductive film 1 extends in a planar direction perpendicular to the thickness direction, and the light-adjusting conductive film 1 has a flat surface (top surface) and a flat surface (bottom surface) in the thickness direction.

[0032] The light-adjusting conductive film 1 comprises, in order, a substrate 2, a blackened layer 3, and an inorganic layer 4, in the thickness direction. That is, the light-adjusting conductive film 1 comprises: a blackened layer 3 disposed on one side of the substrate 2 in the thickness direction; and an inorganic layer 4 disposed on one side of the blackened layer 3 in the thickness direction. Specifically, Figure 1As shown, the light-adjustable conductive film 1 of the first embodiment comprises: a substrate 2; a blackened layer 3 disposed on one side of the substrate 2 in the thickness direction; and an inorganic layer 4 disposed on one side of the blackened layer 3 in the thickness direction. It should be noted that the light-adjustable conductive film 1 may also include a protective film 23 and an adhesive layer 24 on the other side of the substrate 2 in the thickness direction (see FIG. Figure 3B The protective film 23 and the adhesive layer 24 are peeled off from the light control conductive film 1 at a predetermined time.

[0033] If the light-adjusting conductive film 1 has the above-described layer structure, the transmittance of light in the visible light range through the blackened layer 3 (visible light transmittance) is excellent. Moreover, before the high-wavelength light is absorbed by the blackened layer 3, the high-wavelength light can be reflected by the metal layer 42 (described later) included in the inorganic layer 4. In other words, the reflectivity of light in the high-wavelength range (solar reflectivity) is excellent. As a result, the thermal insulation properties are excellent. It should be noted that the excellent visible light transmittance means that the visible light transmittance is adjusted to an appropriate range.

[0034] <Base material>

[0035] Substrate 2 supports the light-adjusting conductive film 1. Substrate 2 is the bottom layer of the light-adjusting conductive film 1. Substrate 2 is not particularly limited as long as it is a substrate commonly used for light-adjusting conductive films. Substrate 2 includes, for example, a transparent substrate 21 and a cured resin layer 22 disposed on both sides of the transparent substrate 21 in the thickness direction.

[0036] The transparent substrate 21 has a film shape (including a sheet shape) and is, for example, a flexible polymer film.

[0037] As the material of the transparent substrate 21, for example, cellulose resin, polyester resin, (meth) acrylic resin (acrylic resin and / or methacrylic resin), olefin resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, polystyrene resin, norbornene resin and polyvinyl alcohol resin can be listed. As polyester resin, for example, polyethylene terephthalate (PET), polybutylene terephthalate and polyethylene naphthalate can be listed. As olefin resin, for example, polyethylene, polypropylene and cycloolefin polymer (COP) can be listed. As cellulose resin, for example, cellulose triacetate (TAC) can be listed. From the viewpoints of transparency, heat resistance, mechanical strength, etc., the transparent substrate 21 can preferably include a polyester film. More preferably, a polyethylene terephthalate film can be listed. The material of the transparent substrate 21 can be used alone or in combination of two or more.

[0038] The visible light transmittance (JIS K-7105) of the transparent substrate 21 is, for example, 80% or more, preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more, and is, for example, 100% or less. It should be noted that visible light transmittance has the same meaning as total light transmittance (hereinafter the same).

[0039] From the viewpoint of strength and handleability, the thickness of the transparent substrate 21 is, for example, 10 μm or more, preferably 30 μm or more, more preferably 40 μm or more, and, for example, 300 μm or less, preferably 150 μm or less, more preferably 80 μm or less.

[0040] The thickness of the transparent base material 21 can be measured using, for example, a film thickness meter.

[0041] The cured resin layer 22 is a layer that improves the mechanical properties of the light control conductive film 1. The cured resin layer 22 is in contact with both surfaces of the transparent base material 21 in the thickness direction, for example.

[0042] Examples of the cured resin layer 22 include a hard coat layer and an anti-blocking layer. A hard coat layer is preferred. The hard coat layer, for example, prevents scratches on the exposed surface of the light-adjusting conductive film 1. The anti-blocking layer imparts anti-blocking properties to the surfaces of multiple light-adjusting conductive films 1 that are in contact with each other, for example, when the light-adjusting conductive films 1 are stacked in the thickness direction.

[0043] The cured resin layer 22 is, for example, a cured product of a curable resin composition. Specifically, the cured resin layer 22 can be formed by applying a curable resin composition to both surfaces of the transparent substrate 21 in the thickness direction, drying it as needed, and then curing it.

[0044] The curable resin composition contains a curable resin. Examples of curable resins include polyester resins, acrylic urethane resins, acrylic resins (excluding acrylic urethane resins), urethane resins (excluding acrylic urethane resins), amide resins, silicone resins, epoxy resins, and melamine resins. Curable resins may be used alone or in combination of two or more. Examples of curable resin compositions include ultraviolet-curable resin compositions and thermosetting resin compositions.

[0045] The curable resin composition may contain fine particles from the viewpoint of adjusting the hardness, surface roughness, refractive index, and imparting anti-glare properties to the cured resin layer 22. Examples of the fine particles include inorganic particles (eg, silica) and organic particles.

[0046] Furthermore, the curable resin composition may contain additives such as a photopolymerization initiator, a solvent (eg, ethyl acetate, toluene), a leveling agent, a thixotropic agent, and an antistatic agent.

[0047] The thickness of the cured resin layer 22 is, for example, 0.1 μm or greater, preferably 0.5 μm or greater, more preferably 1 μm or greater, and for example, 15 μm or less, preferably 10 μm or less, more preferably 5 μm or less. It should be noted that the thickness of the cured resin layer 22 refers to the thickness of the cured resin layer 22 formed on either one surface in the thickness direction or the other surface in the thickness direction of the transparent substrate 21, and does not refer to the total thickness.

[0048] When the thickness of the cured resin layer 22 is greater than or equal to the lower limit, the cured resin layer 22 can be easily formed and the function of the cured resin layer 22 can be fully exhibited. When the thickness of the cured resin layer 22 is less than or equal to the upper limit, the light-adjusting conductive film 1 can be made thinner.

[0049] From the perspective of improving the adhesion with the blackening layer 3 or the metal oxide layer 5, the surface on one side of the thickness direction of the substrate 2 (the contact surface of the cured resin layer 22 with the blackening layer 3 or the metal oxide layer 5 described later) can also be subjected to surface modification treatments such as corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, saponification treatment, and treatment using a coupling agent.

[0050] The visible light transmittance (JIS K-7105) of the substrate 2 is, for example, 80% or more, preferably 85% or more, more preferably 88% or more, further preferably 90% or more, and for example, 100% or less.

[0051] From the viewpoint of strength and handleability, the thickness of the substrate 2 is, for example, 10 μm or more, preferably 30 μm or more, more preferably 40 μm or more, and, for example, 300 μm or less, preferably 150 μm or less, more preferably 80 μm or less.

[0052] <Blackened layer>

[0053] The blackened layer 3 is disposed on one side in the thickness direction of the substrate 2. In the first embodiment, the blackened layer 3 is in contact with one surface of the substrate 2 in the thickness direction.

[0054] The blackened layer 3 has high light absorption. In other words, the blackened layer 3 can adjust the visible light transmittance to an appropriate range.

[0055] The blackened layer 3 may contain, for example, an inorganic substance or an organic substance. From the viewpoint of light resistance, it is preferably composed of an inorganic substance and does not contain an organic substance. It is more preferably composed of an inorganic substance.

[0056] When an organic substance is included, the blackened layer 3 may include, for example, a thermoplastic resin and a colorant. The thermoplastic resin is not particularly limited. The colorant is not particularly limited as long as it is a black colorant, and an example thereof is carbon black.

[0057] In the case of not containing organic matter, the blackened layer 3 contains, for example, a metal (elemental metal) and a metal compound, preferably an elemental metal and a metal oxide. The blackened layer 3 may contain multiple elemental metals or multiple metal compounds.

[0058] A metal compound is a compound of a metal and a non-metal. Examples of metal compounds include metal oxides, metal nitrides, and metal carbides. Metal oxides are preferred. Examples of the metal (first metal) in the metal compound include indium (In), copper (Cu), molybdenum (Mo), and iron (Fe). The first metal is preferably at least one selected from the group consisting of In, Cu, Mo, and Fe. In and Cu are more preferred. That is, examples of metal compounds include indium oxide and copper oxide. In addition, the first metal can be used alone or in combination of two or more. It should be noted that copper oxide includes copper (I) oxide and copper (II) oxide.

[0059] Examples of the elemental metal (second metal) include In, Cu, Mo, and Fe. The second metal is preferably at least one selected from the group consisting of In, Cu, Mo, and Fe. More preferably, Cu is used. The second metal may be the same as or different from the first metal. Furthermore, the second metal may be used alone or in combination of two or more.

[0060] The proportion of the metal compound in the blackened layer 3 is, for example, 70 mass % or more, preferably 80 mass % or more, more preferably 85 mass % or more, and, for example, 99 mass % or less, preferably 95 mass % or less, more preferably 90 mass % or less.

[0061] The proportion of the elemental metal in the blackened layer 3 is, for example, 1 mass % or more, preferably 5 mass % or more, more preferably 10 mass % or more, and for example, 30 mass % or less, preferably 20 mass % or less, more preferably 15 mass % or less.

[0062] When the ratio of the metal compound and the ratio of the elemental metal in the blackened layer 3 are within the above ranges, the visible light transmittance is excellent.

[0063] The blackened layer 3 more preferably contains copper, copper oxide, and indium oxide. It should be noted that the blackened layer 3 may also contain trace amounts of other metal compounds. Examples of trace amounts of other metal compounds include copper hydroxide.

[0064] When the blackened layer 3 contains the above-mentioned elemental metal and metal compound, the visible light transmittance is excellent.

[0065] When the blackened layer 3 includes indium oxide, the ratio of In in the blackened layer 3 is, for example, 40 atomic % or more, preferably 50 atomic % or more, and, for example, 90 atomic % or less, preferably 80 atomic % or less.

[0066] When the ratio of In in the blackened layer 3 is within the above range, the content of the inorganic substance (for example, copper) having high light absorption properties can be sufficiently ensured.

[0067] When the blackened layer 3 contains copper and / or copper oxide, the proportion of Cu in the blackened layer 3 is, for example, 10 atomic % or more, preferably 20 atomic % or more, and, for example, 60 atomic % or less, preferably 50 atomic % or less.

[0068] When the ratio of Cu in the blackened layer 3 is within the above range, the visible light transmittance is excellent.

[0069] When the blackened layer 3 contains copper (elemental metal) and copper oxide, the proportion of Cu as the elemental metal in the total amount of copper (elemental metal) and copper oxide is, for example, greater than 50 atomic %, preferably greater than 60 atomic %, and, for example, less than 90 atomic %, preferably less than 80 atomic %.

[0070] When the blackened layer 3 contains copper (elemental metal) and copper oxide, the proportion of Cu in copper oxide in the total amount of copper (elemental metal) and copper oxide is, for example, 10 atomic % or more, preferably 20 atomic % or more, and, for example, 50 atomic % or less, preferably 40 atomic % or less.

[0071] When the blackened layer 3 contains copper oxide, the ratio of Cu in copper (I) oxide in the total amount of copper (elemental metal) and copper oxide is, for example, 5 atomic % or more, preferably 10 atomic % or more, and, for example, 40 atomic % or less, preferably 30 atomic % or less.

[0072] When the blackened layer 3 contains copper oxide, the ratio of Cu in copper (II) oxide in the total amount of copper (elemental metal) and copper oxide is, for example, 3 atomic % or more, preferably 6 atomic % or more, and, for example, 40 atomic % or less, preferably 30 atomic % or less.

[0073] When the ratio of Cu as a single metal and the ratio of Cu in copper oxide (the ratio of Cu in copper (I) oxide and the ratio of Cu in copper (II) oxide) in the total amount of copper (single metal) and copper oxide are within the above ranges, the visible light transmittance is excellent.

[0074] The thickness of the blackened layer 3 is, for example, 1 nm to 40 nm, preferably 3 nm to 38 nm, more preferably 5 nm to 35 nm, and further preferably 10 nm to 35 nm.

[0075] The thickness of the blackened layer 3 is, for example, 1 nm or more, preferably 3 nm or more, more preferably 5 nm or more, further preferably 10 nm or more, and is, for example, less than 40 nm, preferably 38 nm or less, more preferably 35 nm or less.

[0076] If the thickness of the blackened layer 3 is greater than or equal to the above lower limit, the visible light transmittance is excellent. In addition, if the thickness of the blackened layer 3 is less than or equal to the above upper limit, the adhesion to the substrate 2 or the metal oxide layer 5 described later is excellent, and an excessive decrease in the visible light transmittance can be suppressed.

[0077] The visible light transmittance (JIS K-7105) of the blackened layer 3 is, for example, 35% or more, and for example, 90% or less.

[0078] The light transmittance (Y value) of the blackened layer 3 at wavelengths of 380 nm to 780 nm in the CIE-XYZ colorimetric system is, for example, 0.001% to 0.1%, preferably 0.005% to 0.05%, and more preferably 0.01% to 0.03%. The light transmittance can be measured, for example, using a spectrophotometer (product name: U-4100, manufactured by Hitachi High-Tech Science Co., Ltd.).

[0079] <Inorganic layer>

[0080] The inorganic layer 4 is disposed on one side in the thickness direction of the blackened layer 3. Preferably, the inorganic layer 4 is disposed on one surface in the thickness direction of the blackened layer 3. In other words, the inorganic layer 4 is preferably in contact with one surface in the thickness direction of the blackened layer 3.

[0081] The inorganic layer 4 comprises, in order, a first transparent conductive layer 41, a metal layer 42, and a second transparent conductive layer 43, arranged along one side in the thickness direction. Specifically, the inorganic layer 4 comprises the first transparent conductive layer 41; the metal layer 42 disposed on one side of the first transparent conductive layer 41 in the thickness direction; and the second transparent conductive layer 43 disposed on one side of the metal layer 42 in the thickness direction.

[0082] The inorganic layer 4 is, for example, a layer formed by a dry coating method (dry coating layer). Examples of dry coating layers include sputtering layers formed by sputtering and vapor-deposited layers formed by vapor deposition. A sputtering layer is preferred. Specifically, the first transparent conductive layer 41, the metal layer 42, and the second transparent conductive layer 43 are preferably sputtered layers.

[0083] [First transparent conductive layer]

[0084] The first transparent conductive layer 41 is disposed on one side in the thickness direction of the blackened layer 3. Preferably, it is disposed on one surface in the thickness direction of the blackened layer 3. In other words, the first transparent conductive layer 41 is preferably in contact with one surface in the thickness direction of the blackened layer 3.

[0085] Since the first transparent conductive layer 41 is disposed on one surface of the blackened layer 3 in the thickness direction, the metal layer 42 is not in direct contact with the blackened layer 3, and discoloration of the metal layer 42 can be suppressed. As a result, the visible light transmittance is excellent.

[0086] Examples of the first transparent conductive layer 41 include metal layers and metal oxide layers. A metal oxide layer is preferred. Examples of metals forming the metal oxide of the first transparent conductive layer 41 include indium (In), zinc (Zn), tin (Sn), magnesium (Mg), nickel (Ni), cobalt (Co), and chromium (Cr). An indium tin composite oxide layer (ITO layer) is more preferred as the first transparent conductive layer 41.

[0087] When the first transparent conductive layer 41 is an ITO layer, the ratio of tin oxide in the ITO layer to the total content of indium oxide (In2O3) and tin oxide (SnO2) is, for example, 1.0 mass% or more, preferably 5.0 mass% or more, more preferably 10.0 mass% or more, and, for example, 20.0 mass% or less, preferably 18.0 mass% or less, more preferably 15.0 mass% or less.

[0088] When the ratio of tin oxide to the total content of indium oxide and tin oxide in the ITO layer is within the above range, the resistance value can be appropriately reduced.

[0089] The thickness of the first transparent conductive layer 41 is, for example, 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more, and is, for example, 200 nm or less, preferably 100 nm or less, more preferably 50 nm or less.

[0090] When the thickness of the first transparent conductive layer 41 is greater than or equal to the lower limit, the resistance value can be appropriately reduced. Furthermore, when the thickness of the first transparent conductive layer 41 is less than or equal to the upper limit, the first transparent conductive layer 41 has excellent adhesion to the blackened layer 3, allowing the thickness of the light-adjusting conductive film 1 to be reduced.

[0091] [Metal layer]

[0092] The metal layer 42 is disposed on one side in the thickness direction of the first transparent conductive layer 41. Preferably, the metal layer 42 is disposed on one surface in the thickness direction of the first transparent conductive layer 41. In other words, the metal layer 42 is preferably in contact with one surface in the thickness direction of the first transparent conductive layer 41.

[0093] The metal layer 42 is formed of, for example, a metal having light reflectivity (excellent solar reflectivity).

[0094] Examples of metals forming the metal layer 42 include aluminum (Al), silver (Ag), titanium (Ti), and alloys thereof. From the perspective of excellent reflectivity for visible light, Al, Ag, and alloys thereof are preferred. More preferred are Ag and silver alloys. Specifically, examples of the metal layer 42 include silver layers and silver alloy layers.

[0095] The thickness of the metal layer 42 is, for example, 1 nm to 30 nm, preferably 3 nm to 20 nm, more preferably 5 nm to 15 nm, and even more preferably 5 nm to 10 nm.

[0096] The thickness of the metal layer 42 is, for example, 1 nm or more, preferably 3 nm or more, more preferably 5 nm or more, and is, for example, 30 nm or less, preferably 20 nm or less, more preferably 15 nm or less, further preferably 10 nm or less.

[0097] When the thickness of the metal layer 42 is equal to or greater than the lower limit, the solar reflectance is excellent. Furthermore, when the thickness of the metal layer 42 is equal to or less than the upper limit, an excessive decrease in the resistance value can be suppressed.

[0098] [Second transparent conductive layer]

[0099] The second transparent conductive layer 43 is disposed on one side in the thickness direction of the metal layer 42, for example. Preferably, the second transparent conductive layer 43 is disposed on one surface in the thickness direction of the metal layer 42. In other words, the second transparent conductive layer 43 is in contact with one surface in the thickness direction of the metal layer 42.

[0100] Examples of the second transparent conductive layer 43 include metal layers, metal oxide layers, and metal nitride layers. A metal oxide layer is preferred. Examples of the metal oxide forming the second transparent conductive layer 43 include indium (In), zinc (Zn), tin (Sn), magnesium (Mg), nickel (Ni), cobalt (Co), and chromium (Cr). The second transparent conductive layer 43 is preferably an ITO layer.

[0101] When the second transparent conductive layer 43 is an ITO layer, the ratio of tin oxide in the ITO layer to the total content of indium oxide (In2O3) and tin oxide (SnO2) is, for example, 1.0 mass% or more, preferably 5.0 mass% or more, more preferably 10.0 mass% or more, and, for example, 20.0 mass% or less, preferably 18.0 mass% or less, more preferably 15.0 mass% or less.

[0102] When the ratio of tin oxide to the total content of indium oxide and tin oxide in the ITO layer is within the above range, the resistance value can be appropriately reduced.

[0103] The thickness of the second transparent conductive layer 43 is, for example, 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more, and is, for example, 200 nm or less, preferably 100 nm or less, more preferably 50 nm or less.

[0104] If the thickness of the second transparent conductive layer 43 is greater than or equal to the lower limit, the resistance value can be appropriately reduced. Furthermore, if the thickness of the second transparent conductive layer 43 is less than or equal to the upper limit, the second transparent conductive layer 43 has excellent adhesion to the metal layer 42, allowing the thickness of the light-adjusting conductive film 1 to be reduced.

[0105] The total thickness of the inorganic layer 4 (the thickness of the inorganic layer 4) is, for example, 30 nm or more, preferably 50 nm or more, more preferably 70 nm or more, and is, for example, 500 nm or less, preferably 300 nm or less, more preferably 200 nm or less, and further preferably 100 nm or less.

[0106] When the thickness of the inorganic layer 4 is equal to or greater than the lower limit, the resistance value can be appropriately reduced. Furthermore, when the thickness of the inorganic layer 4 is equal to or less than the upper limit, the light control conductive film 1 can be thinned.

[0107] The visible light transmittance (JIS K-7105) of the inorganic layer 4 is, for example, 70% or more, and for example, 99% or less.

[0108] The ratio of the thickness of the metal layer 42 in the inorganic layer 4 is, for example, 3% or more, preferably 5% or more, more preferably 8% or more, and for example, 17% or less, preferably 13% or less, more preferably 11% or less.

[0109] When the ratio of the thickness of the metal layer 42 in the inorganic layer 4 is greater than or equal to the lower limit, the solar reflectance is excellent. Furthermore, when the ratio of the thickness of the metal layer 42 in the inorganic layer 4 is less than or equal to the upper limit, an excessive decrease in resistance can be suppressed.

[0110] The ratio of the thickness of the blackened layer 3 to the thickness of the inorganic layer 4 (the thickness of the blackened layer 3 / the thickness of the inorganic layer 4) is, for example, greater than 0.01, preferably greater than 0.03, more preferably greater than 0.05, and, for example, less than 0.5, preferably less than 0.4, more preferably less than 0.2, and further preferably less than 0.1.

[0111] When the ratio of the thickness of the blackened layer 3 to the thickness of the inorganic layer 4 is within the above range, the visible light transmittance is excellent.

[0112] From the viewpoint of strength and handleability, the thickness of the light-adjusting conductive film 1 is, for example, 100 μm or more, preferably 130 μm or more, more preferably 150 μm or more, and, for example, 800 μm or less, preferably 500 μm or less, more preferably 300 μm or less.

[0113] The electrical resistance (surface resistance) of the light control conductive film 1 is, for example, 6 Ω / □ to 15 Ω / □, preferably 8 Ω / □ to 14 Ω / □, and more preferably 10 Ω / □ to 13 Ω / □.

[0114] The resistance value (surface resistance) of the light-adjusting conductive film 1 is, for example, 6Ω / □ or more, preferably 8Ω / □ or more, more preferably 10Ω / □ or more, and is, for example, 15Ω / □ or less, preferably 14Ω / □ or less, more preferably 13Ω / □ or less.

[0115] When the resistance value (surface resistance) of the conductive film 1 for light control is greater than or equal to the lower limit, the risk of short circuit etc. can be suppressed. When the resistance value (surface resistance) of the conductive film 1 for light control is less than or equal to the upper limit, the conductive property is excellent.

[0116] The resistance value (surface resistance) of the conductive film 1 for light control can be measured by a four-probe method in accordance with JIS K 7194 (1994). Specific examples will be described later.

[0117] The resistance value (surface resistance) of the light-adjusting conductive film 1 can be adjusted by the thickness and material of the blackened layer 3 , the total thickness and material of the inorganic layer 4 , the thickness of each layer constituting the inorganic layer 4 , and the like.

[0118] The visible light transmittance of the light control conductive film 1 is, for example, 20% to 85%, preferably 30% to 80%, and more preferably 30% to 70%.

[0119] The visible light transmittance of the light control conductive film 1 is, for example, 20% or more, preferably 30% or more, and for example, 85% or less, preferably 80% or less, and more preferably 70% or less.

[0120] When the visible light transmittance of the light control conductive film 1 is within the above-mentioned range, a sufficient light control function (contrast difference between the light shielding mode and the transmission mode) can be ensured.

[0121] The visible light transmittance of the conductive film 1 for light control can be measured using a haze meter in accordance with JIS K 7375 (2008). Specific examples will be described later.

[0122] The visible light transmittance of the light-adjusting conductive film 1 can be adjusted by the thickness and material of the blackened layer 3 , the total thickness and material of the inorganic layer 4 , the thickness of each layer constituting the inorganic layer 4 , etc. In particular, the visible light transmittance can be adjusted by the thickness and material of the blackened layer 3 .

[0123] The solar reflectance of the light control conductive film 1 is, for example, 33% or more, preferably 34% or more, and more preferably 35% or more.

[0124] The solar reflectance of the conductive film 1 for light control can be determined by the following formula (1) with reference to ISO 13837. λ It represents spectral reflectance and can be measured using a spectrophotometer. Specifically, it is shown in the examples described below.

[0125]

[0126] Re: Solar reflectivity (%)

[0127] R λ : Spectral reflectance (%)

[0128] E′ λ(n) : Standard solar spectrum distribution

[0129] The solar reflectance of the light-controlling conductive film 1 can be adjusted by the total thickness and material of the inorganic layer 4 , the thickness of each layer constituting the inorganic layer 4 , etc. In particular, it can be adjusted by the thickness of the metal layer 42 .

[0130] The change rate of visible light transmittance of the light control conductive film 1 in a high temperature and high humidity environment is, for example, 15% or less, preferably 10% or less, more preferably 5% or less, further preferably 3% or less, and particularly preferably 1% or less.

[0131] When the rate of change in visible light transmittance of the light control conductive film 1 under a high-temperature and high-humidity environment is equal to or less than the above upper limit, the reliability is excellent.

[0132] The rate of change in the visible light transmittance of the light control conductive film 1 under a high-temperature and high-humidity environment can be determined by a method described in Examples below.

[0133] The rate of change of the visible light transmittance of the dimming conductive film 1 under a high temperature and high humidity environment can be adjusted by the thickness and material of the blackened layer 3, the total thickness and material of the inorganic layer 4, the thickness of each layer constituting the inorganic layer 4, the thickness and composition of the metal oxide layer 5 described later, etc.

[0134] 2. Second Implementation

[0135] Reference Figure 2A second embodiment of the light control conductive film of the present invention will be described. However, the same configuration as in the first embodiment will be omitted.

[0136] The light-adjusting conductive film 1 comprises, in order from one side in the thickness direction, a substrate 2, a blackened layer 3, and an inorganic layer 4, and further comprises a metal oxide layer 5 between the substrate 2 and the blackened layer 3. In other words, the light-adjusting conductive film 1 comprises: a substrate 2; a metal oxide layer 5 disposed on one side in the thickness direction of the substrate 2; a blackened layer 3 disposed on one side in the thickness direction of the metal oxide layer 5; and an inorganic layer 4 disposed on one side in the thickness direction of the blackened layer 3. Specifically, Figure 2 As shown, the light-adjustable conductive film 1 of the second embodiment includes: a substrate 2; a metal oxide layer 5 disposed on one side of the substrate 2 in the thickness direction; a blackened layer 3 disposed on one side of the metal oxide layer 5 in the thickness direction; and an inorganic layer 4 disposed on one side of the blackened layer 3 in the thickness direction. It should be noted that the light-adjustable conductive film 1 may also include a protective film 23 and an adhesive layer 24 on the other side of the substrate 2 in the thickness direction (see FIG. Figure 4C The protective film 23 and the adhesive layer 24 are peeled off from the light control conductive film 1 at a predetermined time.

[0137] If the conductive film 1 for dimming has the above-mentioned layer structure, the visible light transmittance can be adjusted by the black layer 3, and before the light in the high wavelength region is absorbed by the black layer 3, the light in the high wavelength region can be reflected by the metal layer 42 possessed by the inorganic layer 4. That is, the solar reflectivity is excellent. As a result, the heat insulation property is excellent. In addition, the conductive film 1 for dimming further includes a metal oxide layer 5 between the substrate 2 and the black layer 3. Therefore, the change in visible light transmittance under high temperature and high humidity environments can be further suppressed. Specifically, the metal oxide layer 5 can suppress the increase in visible light transmittance of the black layer caused by the influence of degassing from the substrate 2 under high temperature and high humidity environments (in detail, the increase in the proportion of copper (II) oxide in the copper atoms contained in the black layer). As a result, the reliability is further excellent.

[0138] <Metal oxide layer>

[0139] The metal oxide layer 5 is disposed between the substrate 2 and the blackened layer 3. That is, the metal oxide layer 5 is preferably in contact with one surface of the substrate 2 in the thickness direction and in contact with the other surface of the blackened layer 3 in the thickness direction.

[0140] The metal oxide layer 5 is formed, for example, by a dry coating method (dry coating layer). Examples of the dry coating layer include a sputtering layer formed by a sputtering method and a vapor deposition layer formed by a vapor deposition method. Preferably, a sputtering layer is used.

[0141] Examples of the metal oxide layer 5 include metal layers and metal oxide layers. A metal oxide layer is preferred. Examples of the metal oxide forming the metal oxide layer 5 include indium (In), zinc (Zn), tin (Sn), magnesium (Mg), nickel (Ni), cobalt (Co), and chromium (Cr). The metal oxide layer 5 is more preferably an indium tin composite oxide layer (ITO layer).

[0142] When the metal oxide layer 5 is an ITO layer, the ratio of tin oxide in the ITO layer to the total content of indium oxide (In2O3) and tin oxide (SnO2) is, for example, 1.0 mass% or more, preferably 5.0 mass% or more, more preferably 10.0 mass% or more, and, for example, 20.0 mass% or less, preferably 18.0 mass% or less, more preferably 15.0 mass% or less.

[0143] When the ratio of tin oxide to the total content of indium oxide and tin oxide in the ITO layer is within the above range, the resistance value can be appropriately reduced.

[0144] The thickness of the metal oxide layer 5 is preferably thinner than the first transparent conductive layer 41 and the second transparent conductive layer 43 described above.

[0145] The thickness of the metal oxide layer 5 is, for example, 0.5 nm to 80 nm, preferably 1 nm to 40 nm, more preferably 2 nm to 20 nm, and further preferably 3 nm to 10 nm.

[0146] The thickness of the metal oxide layer 5 is, for example, 0.5 nm or more, preferably 1 nm or more, more preferably 2 nm or more, further preferably 3 nm or more, and, for example, 80 nm or less, preferably less than 40 nm, more preferably 20 nm or less, further preferably 10 nm or less, and particularly preferably 6 nm or less.

[0147] When the thickness of the metal oxide layer 5 is greater than or equal to the lower limit, changes in visible light transmittance in high-temperature and high-humidity environments can be suppressed. Consequently, reliability is further improved. Furthermore, when the thickness of the metal oxide layer 5 is less than or equal to the upper limit, the metal oxide layer 5 exhibits excellent adhesion to the substrate 2, enabling the thickness of the light-adjusting conductive film 1 to be reduced.

[0148] The above-mentioned conductive film for light control 1 is preferably used for a sunroof of a car or the like.

[0149] 3. Method for manufacturing a conductive film for light adjustment

[0150] <Method for Manufacturing Light Control Conductive Film According to First Embodiment>

[0151] Reference Figure 3A-3BNext, a method for producing the light control conductive film 1 according to the first embodiment will be described. The light control conductive film 1 is produced, for example, in the roll-to-roll method as follows.

[0152] Figure 3A It indicates the process of preparing a substrate with a protective film (preparation process), Figure 3B This shows a step of forming the blackened layer 3 and the inorganic layer 4 on the substrate with a protective film (lamination step).

[0153] (Preparation process)

[0154] like Figure 3A Specifically, a transparent substrate 21 is first prepared, and a curable resin composition is applied to both sides of the transparent substrate 21 in the thickness direction, dried as needed, and then cured to form a cured resin layer 22. In this way, the substrate 2 is obtained.

[0155] Next, a protective film 23 is laminated to the other thickness-direction surface of the substrate 2. Specifically, one thickness-direction surface of the single-sided adhesive protective film is laminated to the other thickness-direction surface of the substrate 2. It should be noted that the single-sided adhesive protective film comprises: a protective film 23; and an adhesive layer 24 located on one thickness-direction surface of the protective film 23. Lamination of the substrate 2 and the single-sided adhesive protective film is performed using, for example, a roll-to-roll laminating apparatus.

[0156] [Protective film]

[0157] The protective film 23 is a film for preventing damage to the light control conductive film 1. The protective film 23 is peeled off from the light control conductive film 1 together with the adhesive layer 24 at a predetermined timing.

[0158] The protective film 23 has a film shape (including a sheet shape) and is, for example, a flexible polymer film.

[0159] Examples of materials for the protective film 23 include the same materials as those for the transparent substrate 21. From the viewpoints of transparency, heat resistance, mechanical strength, etc., the protective film 23 is preferably a polyester film, and more preferably a polyethylene terephthalate film.

[0160] From the viewpoint of strength and handleability, the thickness of the protective film 23 is thicker than that of the transparent substrate 21 , and is, for example, 50 μm or more, preferably 100 μm or more, and, for example, 500 μm or less, preferably 300 μm or less.

[0161] The thickness of the protective film 23 can be measured using, for example, a film thickness meter.

[0162] [Adhesive layer]

[0163] The adhesive layer 24 is a layer that bonds the base material 2 and the protective film 23. That is, the adhesive layer 24 is in contact with one surface of the protective film 23 in the thickness direction and is in contact with the other surface of the base material 2 in the thickness direction.

[0164] The adhesive layer 24 is, for example, a layer made of an adhesive, and is formed by applying the adhesive to one surface in the thickness direction of the protective film 23. The adhesive is not particularly limited as long as it is an adhesive commonly used for light-adjustable conductive films and can be peeled off the protective film 23 at a predetermined time. For example, an acrylic adhesive can be used.

[0165] From the viewpoint of ensuring adhesiveness, the thickness of the adhesive layer 24 is, for example, 5 μm or more, preferably 10 μm or more, and, for example, 50 μm or less, preferably 40 μm or less.

[0166] By bonding the other thickness-direction surface of the substrate 2 to one thickness-direction surface of the single-sided adhesive protective film (one thickness-direction surface of the adhesive layer 24 ), a substrate with a protective film can be obtained.

[0167] (Lamination process)

[0168] Then, if Figure 3B As shown, a blackened layer 3 and an inorganic layer 4 are formed on one side of the thickness direction of the substrate with a protective film (one side of the thickness direction of the substrate 2). Specifically, the blackened layer 3 is formed on one side of the thickness direction of the substrate with a protective film, and then the inorganic layer 4 is formed on one side of the thickness direction of the blackened layer 3. It should be noted that the inorganic layer 4 is sequentially formed with a first transparent conductive layer 41, a metal layer 42, and a second transparent conductive layer 43 toward one side of the thickness direction.

[0169] The blackened layer 3 and the inorganic layer 4 are formed, for example, by a dry coating method. Examples of dry coating methods include sputtering and vapor deposition. Sputtering is preferred. Examples of sputtering methods include diode sputtering, ECR (electron cyclotron resonance) sputtering, magnetron sputtering, and ion beam sputtering. Magnetron sputtering is preferred.

[0170] In the sputtering method, for example, a sputtering film forming device is used. The sputtering film forming device can implement the film forming process in a roll-to-roll manner. In the process of forming the blackened layer and the inorganic layer (lamination process), a long substrate with a protective film is used as a working film, which travels from a take-off roller to a take-up roller, and the materials of the above-mentioned blackened layer 3 and inorganic layer 4 are sequentially formed on one side of the thickness direction of the substrate with the protective film. The travel speed of the working film is, for example, 0.5 m / min to 10.0 m / min.

[0171] It should be noted that in the sputtering method, a sputtering film forming device with one film forming chamber can be used, or a sputtering film forming device with multiple film forming chambers sequentially arranged along the path of travel of the working film can be used. In the case of continuously forming the blackened layer 3 and the inorganic layer 4, it is preferred to use a sputtering film forming device with multiple film forming chambers sequentially arranged along the path of travel of the working film. By setting the series of processes for forming the blackened layer 3 and the inorganic layer 4 as a path line, the working film is not exposed to the atmosphere during the process. Therefore, the adhesion between the layers can be improved.

[0172] Specifically, in the sputtering method, a sputtering gas (inert gas) is introduced into each film-forming chamber of a sputtering film-forming apparatus under vacuum conditions, and a negative voltage is applied to a target disposed on a cathode within each film-forming chamber. This generates a glow discharge, ionizing gas atoms. These gas ions collide with the target surface at high speed, ejecting target material from the target surface, which is then deposited sequentially onto the substrate 2.

[0173] Examples of sputtering gases include argon, krypton, xenon, and mixed gases thereof, preferably argon. Furthermore, a reactive gas (e.g., oxygen) may also be used in combination. It should be noted that when a reactive gas is used in combination, the amount of the reactive gas introduced is set to satisfy the partial pressure of the reactive gas described later.

[0174] The gas pressure in the film formation chamber during film formation by sputtering (sputtering film formation) (the gas pressure in the film formation chamber when sputtering gas or sputtering gas and reactive gas are introduced) is, for example, 0.02 Pa to 1 Pa, and preferably 0.1 Pa to 0.6 Pa.

[0175] When a reactive gas is used in combination, the partial pressure of the reactive gas in the film forming chamber is, for example, 1.0×10 －4 Pa~1.0×10 －2 Pa.

[0176] Examples of a power source for applying a voltage to a target include a DC power source, an AC power source, an MF power source, and an RF power source. Preferably, a DC power source is used.

[0177] The film formation temperature during sputtering (temperature of the working film during film formation) is, for example, 100° C. or lower, preferably 50° C. or lower, more preferably 0° C. or lower, further preferably -5° C. or lower, and for example, -20° C. or higher.

[0178] As materials for the target disposed on the cathode in the film forming chamber, the materials of the above-mentioned blackening layer 3 and the inorganic layer 4 can be listed. Specifically, as target materials for forming the blackening layer 3, for example, metals and metal oxides can be listed, and preferably copper and indium oxide can be listed. As target materials for forming the first transparent conductive layer 41 and the second transparent conductive layer 43, for example, metal oxides can be listed, and preferably indium tin oxide (ITO) can be listed. As target materials for forming the metal layer 42, for example, metals with light reflectivity (excellent solar reflectivity) can be listed, and preferably silver and silver alloys can be listed. It should be noted that if copper is used as a target material for forming the blackening layer 3 in the form of a single metal, part of the copper of the single metal becomes copper oxide during and / or after film formation.

[0179] As described above, a conductive film for light control with a protective film, in which the protective film 23 is bonded to the conductive film for light control 1 of the first embodiment, is obtained.

[0180] The protective film 23 is peeled off from the light control conductive film 1 at a predetermined time together with the adhesive layer 24. Specifically, the protective film 23 and the adhesive layer 24 are peeled off immediately before the light control conductive film 1 is used.

[0181] <Method for Manufacturing Light Control Conductive Film According to Second Embodiment>

[0182] Reference Figures 4A to 4C Next, a method for producing the light control conductive film 1 according to the second embodiment will be described. The light control conductive film 1 is produced, for example, in the roll-to-roll method as follows.

[0183] Figure 4A It indicates the process of preparing a substrate with a protective film (preparation process), Figure 4B represents a step of forming a metal oxide layer 5 on a substrate with a protective film (metal oxide layer forming step), Figure 4C This shows a step of forming the blackened layer 3 and the inorganic layer 4 on the metal oxide layer 5 (lamination step).

[0184] (Preparation process)

[0185] like Figure 4A Specifically, the preparation process is the same as that of the method for producing the light control conductive film 1 according to the first embodiment described above.

[0186] (Metal Oxide Layer Formation Step)

[0187] Next, a metal oxide layer forming step is performed after the preparation step and before the lamination step. Figure 4B As shown, a metal oxide layer 5 is formed on one surface in the thickness direction of the substrate with a protective film.

[0188] The metal oxide layer 5 is formed, for example, by a dry coating method. Examples of dry coating methods include sputtering and vapor deposition. A preferred method is sputtering. Examples of sputtering methods include the same sputtering method as that used in the lamination step of the method for producing the light-adjusting conductive film 1 according to the first embodiment described above. A preferred method is magnetron sputtering.

[0189] In the sputtering method, for example, using a sputtering film-forming apparatus, the same sequence and conditions as those in the lamination step in the method for manufacturing the light-adjusting conductive film 1 according to the first embodiment can be used. It should be noted that the material of the target disposed on the cathode within the film-forming chamber can be the material of the metal oxide layer 5 described above. Specifically, the target material for forming the metal oxide layer 5 can be, for example, a metal oxide, preferably indium tin oxide (ITO).

[0190] It should be noted that the metal oxide layer 5 can be formed using a sputtering film forming apparatus with a single film forming chamber, or a sputtering film forming apparatus with multiple film forming chambers sequentially arranged along the path of travel of the working film. In the case of continuously forming the metal oxide layer 5, the blackened layer 3, and the inorganic layer 4, it is preferred to use a sputtering film forming apparatus with multiple film forming chambers sequentially arranged along the path of travel of the working film. By setting the series of processes for forming the metal oxide layer 5, the blackened layer 3, and the inorganic layer 4 as a single path line, the working film is not exposed to the atmosphere during the process. Therefore, the adhesion between the layers can be improved.

[0191] (Lamination process)

[0192] like Figure 4C As shown, the blackened layer 3 is formed on one surface in the thickness direction of the metal oxide layer 5, and the inorganic layer 4 is formed on one surface in the thickness direction of the blackened layer 3. Specifically, the lamination step is the same as the method for producing the light-adjusting conductive film 1 of the first embodiment described above.

[0193] As described above, a conductive film for light control with a protective film, in which the protective film 23 is bonded to the conductive film for light control 1 according to the second embodiment, is obtained.

[0194] The protective film 23 is peeled off from the light control conductive film 1 at a predetermined time together with the adhesive layer 24. Specifically, the protective film 23 and the adhesive layer 24 are peeled off immediately before the light control conductive film 1 is used.

[0195] (Effect)

[0196] The light-adjustable conductive film of the present invention comprises, in order along one side in the thickness direction, a substrate, a blackened layer, and an inorganic layer. The inorganic layer comprises, in order along one side in the thickness direction, a first transparent conductive layer, a metal layer, and a second transparent conductive layer. This suppresses excessive decreases in resistance, exhibits excellent transmittance for light in the visible light range, and exhibits excellent reflectance for light in the high-wavelength range.

[0197] Example

[0198] The present invention will be further specifically described below with reference to Examples and Comparative Examples. It should be noted that the present invention is not limited to any Examples and Comparative Examples. In addition, the specific numerical values ​​of the mixing ratio (containing ratio), physical property values, parameters, etc. used in the following descriptions may be replaced by the upper limit (defined as "below", "less than") or the lower limit (defined as "above", "greater than") of the corresponding recordings of the mixing ratio (containing ratio), physical property values, parameters, etc. described in the above-mentioned "Specific Embodiments".

[0199] Example 1

[0200] (Preparation process)

[0201] Prepare a substrate having a curable resin layer with a thickness of 2 μm on both sides of a polyethylene terephthalate (PET) film (thickness: 50 μm, manufactured by Toray) as a transparent substrate in the thickness direction. In addition, prepare a single-sided adhesive protective film (thickness: 145 μm, manufactured by Nitto Denko Corporation). It should be noted that the single-sided adhesive protective film has: a protective film (thickness: 125 μm, PET film); and an adhesive layer (thickness: 20 μm), formed on one side of the thickness direction of the protective film, and formed by an acrylic adhesive. Then, the substrate and the single-sided adhesive protective film are set in a roll-to-roll laminating device, and the surface of the substrate on the other side in the thickness direction is bonded to the surface of the single-sided adhesive protective film on one side in the thickness direction (the surface of the adhesive layer on one side in the thickness direction). In this way, a substrate with a protective film is produced.

[0202] (Lamination process)

[0203] Next, a blackened layer and an inorganic layer (a first transparent conductive layer, a metal layer, and a second transparent conductive layer) are formed on one side of the thickness direction of the substrate with a protective film (the surface on one side of the thickness direction of the substrate) by a sputtering method. In the sputtering method, a roll-to-roll sputtering film-forming device (DC magnetron sputtering film-forming device) is used. The sputtering film-forming device includes: a withdrawal chamber, a plurality of film-forming chambers, and a winding chamber. The withdrawal chamber includes a withdrawal roller. A roll of the above-mentioned substrate serving as a working film is provided on the withdrawal roller. The winding chamber includes a winding roller capable of winding up the working film. In the plurality of film-forming chambers, the working film can be moved from the withdrawal chamber to the winding chamber by a roll-to-roll method, and each layer can be formed into a film.

[0204] Specifically, the working film (substrate) was drawn out of the draw-out chamber. Next, an 8nm thick blackened layer, a 40nm thick first transparent conductive layer, an 8nm thick metal layer, and a 40nm thick second transparent conductive layer were sequentially formed. The working film (single-sided adhesive protective film / substrate / blackened layer / first transparent conductive layer / metal layer / second transparent conductive layer) was then wound onto a take-up roll in the take-up chamber. Details of the sputtering conditions for each layer are described below.

[0205] During the formation of the black layer, after the sputtering film forming apparatus was evacuated, argon (Ar) as a sputtering gas and oxygen as a reactive gas were introduced into the film forming chamber to set the pressure in the film forming chamber to 0.2 Pa. It should be noted that the partial pressure of oxygen was approximately 7.0×10 －4 Pa. A sintered body of indium oxide (In2O3) and copper (Cu) (manufactured by Mitsui Kinzoku Co., Ltd.) was used as a target. A DC power supply was used as the power source for applying voltage to the target. The film formation temperature (the temperature of the substrate on which the blackened layer was laminated) was set to -8°C. The type of power supply and film formation temperature were the same for the formation of the first transparent conductive layer, the metal layer, and the second transparent conductive layer.

[0206] During the deposition of the first transparent conductive layer, the sputtering film deposition apparatus was evacuated, and then Ar as a sputtering gas and oxygen as a reactive gas were introduced into the deposition chamber to set the pressure in the deposition chamber to 0.2 Pa. The partial pressure of oxygen was approximately 5.0×10 －3 Pa. In addition, a sintered body of indium oxide and tin oxide (tin oxide concentration: 12.5 mass %) was used as a target.

[0207] During the deposition of the metal layer, the sputtering apparatus was evacuated, and Ar was introduced into the deposition chamber as a sputtering gas to set the pressure in the deposition chamber to 0.3 Pa. A silver alloy (product number: No. 317, manufactured by Mitsubishi Materials Corporation) was used as a target.

[0208] During the deposition of the second transparent conductive layer, the sputtering film deposition apparatus was evacuated, and then Ar as a sputtering gas and oxygen as a reactive gas were introduced into the deposition chamber to set the pressure in the deposition chamber to 0.2 Pa. The partial pressure of oxygen was approximately 5.0×10 －3 Pa. In addition, a sintered body of indium oxide and tin oxide (tin oxide concentration: 12.5 mass %) was used as a target.

[0209] A light-adjustable conductive film with a protective film was prepared as described above, and the single-sided adhesive protective film was peeled off to obtain the light-adjustable conductive film of Example 1. The light-adjustable conductive film of Example 1 comprises, in order from one side in the thickness direction, a substrate (thickness: 54 μm), a blackened layer (thickness: 8 nm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 8 nm), and a second transparent conductive layer (ITO layer, thickness: 40 nm). It should be noted that for the following evaluations, the light-adjustable conductive film was used after the single-sided adhesive protective film was peeled off (the same applies hereinafter).

[0210] Example 2

[0211] A light-adjustable conductive film according to Example 2 was produced in the same manner as the light-adjustable conductive film according to Example 1, except that the thickness of the blackened layer was set to 32 nm. Specifically, the light-adjustable conductive film according to Example 2 comprises, in this order, the following components, along one side in the thickness direction: a substrate (thickness: 54 μm), a blackened layer (thickness: 32 nm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 8 nm), and a second transparent conductive layer (ITO layer, thickness: 40 nm).

[0212] Comparative Example 1

[0213] A light-adjustable conductive film of Comparative Example 1 was produced in the same manner as the light-adjustable conductive film of Example 1, except that a blackened layer was not formed. Specifically, an inorganic layer (specifically, a first transparent conductive layer) was formed on one side of the substrate in the thickness direction. The light-adjustable conductive film of Comparative Example 1 comprises, in this order, a substrate (thickness: 54 μm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 8 nm), and a second transparent conductive layer (ITO layer, thickness: 40 nm) along one side in the thickness direction.

[0214] Comparative Example 2

[0215] A light-adjustable conductive film of Comparative Example 2 was produced in the same manner as the light-adjustable conductive film of Comparative Example 1, except that the thickness of the silver alloy layer was set to 18 nm. The light-adjustable conductive film of Comparative Example 2 comprises, in this order, a substrate (thickness: 54 μm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 18 nm), and a second transparent conductive layer (ITO layer, thickness: 40 nm) along one side in the thickness direction.

[0216] Comparative Example 3

[0217] A light-adjustable conductive film of Comparative Example 3 was produced in the same manner as the light-adjustable conductive film of Comparative Example 1, except that the thickness of the silver alloy layer was set to 30 nm. The light-adjustable conductive film of Comparative Example 3 comprises, in this order, a substrate (thickness: 54 μm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 30 nm), and a second transparent conductive layer (ITO layer, thickness: 40 nm) along one side in the thickness direction.

[0218] Comparative Example 4

[0219] A light-adjusting conductive film of Comparative Example 4 was produced in the same manner as the light-adjusting conductive film of Comparative Example 1, except that a blackening layer having a thickness of 6 nm was formed on one side of the thickness direction of the second transparent conductive layer. It should be noted that the conditions for forming the blackening layer are the same as those described above. That is, an inorganic layer (specifically, a first transparent conductive layer) is formed on one side of the thickness direction of the substrate, and a blackening layer is formed on one side of the thickness direction of the inorganic layer (specifically, a second transparent conductive layer). The light-adjusting conductive film of Comparative Example 4 comprises, in order, toward one side in the thickness direction: a substrate (thickness: 54 μm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 8 nm), a second transparent conductive layer (ITO layer, thickness: 40 nm), and a blackening layer (thickness: 6 nm).

[0220] Comparative Example 5

[0221] A light-adjustable conductive film of Comparative Example 5 was produced in the same manner as the light-adjustable conductive film of Comparative Example 4, except that the thickness of the blackened layer was set to 32 nm. Specifically, the light-adjustable conductive film of Comparative Example 5 comprises, in this order, a substrate (thickness: 54 μm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 8 nm), a second transparent conductive layer (ITO layer, thickness: 40 nm), and a blackened layer (thickness: 32 nm) toward one side in the thickness direction.

[0222] Example 3

[0223] The light-adjustable conductive film of Example 3 was produced in the same manner as the light-adjustable conductive film of Example 1, except for the following. After the preparation step and before the lamination step, a 4 nm thick metal oxide layer was formed on one side of the thickness direction of the substrate with the protective film (one side of the thickness direction of the substrate) by sputtering. Specifically, the same roll-to-roll sputtering film-forming apparatus as used in the lamination step was used. Details of the sputtering conditions for the metal oxide layer are described below.

[0224] After the sputtering film forming apparatus was evacuated, Ar as a sputtering gas and oxygen as a reactive gas were introduced into the film forming chamber to set the pressure in the film forming chamber to 0.2 Pa. The partial pressure of oxygen was about 5.0×10 －3 Pa. Furthermore, a sintered body of indium oxide and tin oxide (tin oxide concentration: 12.5 mass %) was used as a target. A DC power supply was used as a power source for applying voltage to the target. The film formation temperature (the temperature of the protective film-bearing substrate on which the metal oxide layer was laminated) was set to -8°C.

[0225] In this way, a metal oxide layer is formed on one side of the thickness direction of the substrate with a protective film. Then, the above-mentioned lamination step is performed. It should be noted that the metal oxide layer formation step and the lamination step are performed continuously.

[0226] That is, the dimming conductive film of Example 3 comprises, in order toward one side in the thickness direction: a substrate (thickness: 54 μm), a metal oxide layer (ITO layer, thickness: 4 nm), a blackening layer (thickness: 32 nm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 8 nm) and a second transparent conductive layer (ITO layer, thickness: 40 nm).

[0227] Example 4

[0228] A light-adjustable conductive film of Example 4 was produced in the same manner as the light-adjustable conductive film of Example 3, except that the thickness of the metal oxide layer was set to 8 nm. Specifically, the light-adjustable conductive film of Example 4 comprises, in this order, the following components, along one side in the thickness direction: a substrate (thickness: 54 μm), a metal oxide layer (ITO layer, thickness: 8 nm), a blackened layer (thickness: 32 nm), a first transparent conductive layer (ITO layer, thickness: 40 nm), a metal layer (silver alloy layer, thickness: 8 nm), and a second transparent conductive layer (ITO layer, thickness: 40 nm).

[0229] <Evaluation>

[0230] [Resistance value]

[0231] The electrical resistance (surface resistance) of the light control conductive films of Examples 1 and 2 and each comparative example was measured using the four-terminal method in accordance with JIS K 7194 (1994) and evaluated according to the following criteria. The results are shown in Table 1. For the light control conductive films of Examples 3 and 4, only the measurement results are shown in Table 2.

[0232] {Benchmark}

[0233] A: 6Ω / □ or more.

[0234] B: Less than 6Ω / □.

[0235] [Visible light transmittance (total light transmittance)]

[0236] The visible light transmittance of the light control conductive films of Examples 1 and 2 and each comparative example was measured using a haze meter (product name: HZ-V3, manufactured by Suga Test Co., Ltd.) in accordance with JIS K 7375 (2008) and evaluated according to the criteria shown below. The results are shown in Table 1. For the light control conductive films of Examples 3 and 4, only the measurement results are shown in Table 2.

[0237] {Benchmark}

[0238] A: 30% or more and 70% or less.

[0239] B: More than 70% and 80% or less.

[0240] C: less than 30% or greater than 80%.

[0241] [Solar reflectivity]

[0242] With reference to ISO 13837, the solar reflectance Re of the conductive films for light control of Examples 1 and 2 and each comparative example was determined by the above formula (1) and evaluated according to the following criteria. The results are shown in Table 1. λ The measurement was performed using a spectrophotometer (product name: U4100, manufactured by Hitachi High Technologies).

[0243] {Benchmark}

[0244] A: More than 35%.

[0245] B: 33% or more and less than 35%.

[0246] C: less than 33%.

[0247] [Reliability evaluation]

[0248] The conductive films for dimming of Examples 1, 3, and 4 were cut into 5 cm squares. In addition, an object was prepared by bonding OCA (Optical Clear Adhesive) (product name: LUCIACS CS9861UAS, manufactured by Nitto Denko Corporation) to a 5 cm square glass plate (thickness 1.3 mm). Samples were prepared by bonding each 5 cm square conductive film for dimming so that one side in the thickness direction (the side in the thickness direction of the second transparent conductive layer) faced the OCA. Next, the initial visible light transmittance of the sample (initial visible light transmittance) was measured. The measured sample was placed in an oven at 85°C and 85% RH for 240 hours, and the visible light transmittance of the sample after 240 hours (visible light transmittance after 240 hours) was measured. The rate of change (%) was calculated by the following formula and evaluated according to the criteria shown below. The results are shown in Table 2.

[0249] Change rate (%) = |(visible light transmittance after 240 hours) - (initial visible light transmittance) | / (initial visible light transmittance) × 100

[0250] {Benchmark}

[0251] A: Less than 3%.

[0252] B: 3% or more and 15% or less.

[0253] C: greater than 15%.

[0254] [Table 1]

[0255]

[0256] [Table 2]

[0257]

[0258] It should be noted that the above invention is provided in the form of exemplary embodiments of the present invention, but this is merely an example and is not to be construed as limiting. Modifications of the present invention that are obvious to those skilled in the art are encompassed by the claims.

[0259] Industrial applicability

[0260] The light control conductive film 1 of the present invention is preferably used for a sunroof of a car or the like.

Claims

1. A conductive film for light control, wherein: The substrate, the blackened layer and the inorganic layer are sequentially provided on one side in the thickness direction. The inorganic layer includes, in order toward one side in the thickness direction, a first transparent conductive layer, a metal layer, and a second transparent conductive layer.

2. The light-adjusting conductive film according to claim 1, wherein A metal oxide layer is further provided between the substrate and the blackened layer.

3. The light-adjusting conductive film according to claim 2, wherein The metal oxide layer is an indium tin composite oxide layer.

4. The light-adjusting conductive film according to claim 2, wherein The thickness of the metal oxide layer is greater than or equal to 1 nm and less than 40 nm. 5 . The light control conductive film according to claim 1 , wherein: The first transparent conductive layer and the second transparent conductive layer are indium tin composite oxide layers, The metal layer is a silver alloy layer. 6 . The light control conductive film according to claim 1 , wherein: The blackened layer contains metal and metal oxide.

7. The light-adjusting conductive film according to claim 6, wherein The blackened layer includes copper, copper oxide and indium oxide.

8. The light control conductive film according to any one of claims 1 to 4, wherein The thickness of the blackened layer is greater than 1 nm and less than 40 nm.

9. The light control conductive film according to any one of claims 1 to 4, wherein Visible light transmittance is 30% or more and 80% or less, The resistance value is 6Ω / □ or more and 15Ω / □ or less.

10. The light control conductive film according to any one of claims 1 to 4, wherein The solar reflectivity is over 33%.

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