Conductive film for light control

Abstract

To provide a conductive film for light control capable of preventing the resistance value from becoming excessively low and having excellent transmittance for visible light and high reflectance for light in the long wavelength region.SOLUTION: A conductive film 1 for light control comprises, in order toward one side in the thickness direction, a substrate 2, a blackening layer 3, and an inorganic layer 4, the inorganic layer 4 comprising, in order toward one side in the thickness direction, a first transparent conductive layer 41, a metal layer 42, and a second transparent conductive layer 43.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light-control conductive film. [Background technology]

[0002] Conventionally, a light-control conductive film has been known that includes a substrate and an inorganic layer including a metal layer on one surface of the substrate in the thickness direction. Such a light-control conductive film is used for automobile sunroofs, etc. From the viewpoint of design, black sunroofs are preferred for automobile sunroofs. Therefore, the light-control conductive film used for such applications is adjusted to have an appropriate transmittance for light in the visible light region.

[0003] As such a light-control conductive film, one has been proposed in which a blackening layer is disposed on one surface of the inorganic layer in the thickness direction (the surface opposite the substrate with respect to the inorganic layer) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 163897 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] Depending on the application, the light control conductive film is required to have excellent reflectance for light in the long wavelength region from the viewpoint of heat shielding properties.

[0006] In this regard, in order to adjust the transmittance of the light-controlling conductive film for light in the visible light region, it has been considered to increase the thickness of the metal layer in the inorganic layer, but in such a light-controlling conductive film, the thick metal layer excessively reduces the resistance value, which may cause a short circuit.

[0007] On the other hand, the light-control conductive film described in Patent Document 1 has a blackening layer on one thickness-wise surface of the inorganic layer. This allows for adjustment of the transmittance for light in the visible light range, but before the light in the high-wavelength range is reflected by the metal layer in the inorganic layer, the light in the high-wavelength range is absorbed by the blackening layer. As a result, sufficient reflectance cannot be obtained for light in the high-wavelength range, resulting in a problem of reduced heat-shielding properties.

[0008] The present invention aims to provide a light-control conductive film that prevents the resistance value from being excessively low, has excellent transmittance for light in the visible light region, and has excellent reflectance for light in the long wavelength region. [Means for solving the problem]

[0009] The present invention [1] includes a light-control conductive film having a substrate, a blackening layer, and an inorganic layer, in that order toward one side in the thickness direction, and the inorganic layer has a first transparent conductive layer, a metal layer, and a second transparent conductive layer, in that order toward one side in the thickness direction.

[0010] The present invention [2] includes the light-control conductive film according to [1], further comprising a metal oxide layer between the substrate and the blackening layer.

[0011] The present invention [3] includes the light-control conductive film according to [2], in which the metal oxide layer is an indium tin composite oxide layer.

[0012] The present invention [4] includes the light-control conductive film according to [2] or [3], wherein the thickness of the metal oxide layer is 1 nm or more and less than 40 nm.

[0013] The present invention [5] includes the light-control conductive film according to any one of [1] to [4], in which 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.

[0014] The present invention [6] includes the light-control conductive film according to any one of [1] to [5], wherein the blackening layer contains a metal and a metal oxide.

[0015] The present invention [7] includes the light-control conductive film according to any one of [1] to [6], wherein the blackening layer contains copper, copper oxide, and indium oxide.

[0016] The present invention [8] includes the light-control conductive film according to any one of [1] to [7], wherein the thickness of the blackening layer is 1 nm or more and less than 40 nm.

[0017] The present invention [9] includes the light-control conductive film according to any one of [1] to [8], which has a visible light transmittance of 30% or more and 80% or less, and a resistance value of 6 Ω / □ or more and 15 Ω / □ or less.

[0018] The present invention

[10] includes the light control conductive film according to any one of [1] to [9], which has a solar reflectance of 33% or more. [Effects of the Invention]

[0019] The light-control conductive film of the present invention includes a substrate, a blackening layer, and an inorganic layer, arranged in this order toward one side in the thickness direction, and the inorganic layer includes a first transparent conductive layer, a metal layer, and a second transparent conductive layer, arranged in this order toward one side in the thickness direction, thereby preventing an excessive decrease in resistance, and providing excellent transmittance for light in the visible light range and excellent reflectance for light in the long wavelength range. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 shows a cross-sectional view of a first embodiment of the light control conductive film of the present invention. [Figure 2] FIG. 2 shows a cross-sectional view of a second embodiment of the light control conductive film of the present invention. [Figure 3]Fig. 3 shows a method for producing a light-control conductive film with a protective film in which a protective film is bonded to the light-control conductive film shown in Fig. 1. Fig. 3A shows a step of preparing a substrate with a protective film, and Fig. 3B shows a step of forming a blackening layer and an inorganic layer on the substrate with a protective film. [Figure 4] Fig. 4 shows a method for producing a light-control conductive film with a protective film in which a protective film is bonded to the light-control conductive film shown in Fig. 2. Fig. 4A shows a step of preparing a substrate with a protective film, Fig. 4B shows a step of forming a metal oxide layer on the substrate with the protective film, and Fig. 4C shows a step of forming a blackening layer and an inorganic layer on the metal oxide layer. DETAILED DESCRIPTION OF THE INVENTION

[0021] 1. First embodiment A first embodiment of the light control conductive film of the present invention will be described with reference to FIG.

[0022] The light control conductive film 1 is in the form of a film (including a sheet) having a predetermined thickness. The light control conductive film 1 extends in a plane direction perpendicular to the thickness direction, and one surface (upper surface) and the other surface (lower surface) in the thickness direction of the light control conductive film 1 are flat.

[0023] The light-modulating conductive film 1 includes a substrate 2, a blackening layer 3, and an inorganic layer 4, arranged in this order toward one side in the thickness direction. That is, the light-modulating conductive film 1 includes the blackening layer 3 disposed on one side in the thickness direction of the substrate 2, and the inorganic layer 4 disposed on one side in the thickness direction of the blackening layer 3. Specifically, as shown in FIG. 1 , the light-modulating conductive film 1 of the first embodiment includes the substrate 2, the blackening layer 3 disposed on one surface in the thickness direction of the substrate 2, and the inorganic layer 4 disposed on one surface in the thickness direction of the blackening layer 3. The light-modulating conductive film 1 may also include a protective film 23 and an adhesive layer 24 (see FIG. 3B ) on the other side in the thickness direction of the substrate 2. The protective film 23 and the adhesive layer 24 are peeled off from the light-modulating conductive film 1 at a predetermined timing.

[0024] If the light-control conductive film 1 has the layer structure described above, the blackening layer 3 provides excellent transmittance for light in the visible light region (visible light transmittance), and furthermore, the metal layer 42 (described below) of the inorganic layer 4 can reflect light in the high wavelength region before it is absorbed by the blackening layer 3. In other words, the film has excellent reflectance for light in the high wavelength region (solar reflectance). As a result, the film has excellent heat-shielding properties. Note that excellent visible light transmittance means that the visible light transmittance is adjusted to an appropriate range.

[0025] <Base material> The substrate 2 supports the light-control conductive film 1. The substrate 2 is the bottom layer of the light-control conductive film 1. There are no particular limitations on the substrate 2, as long as it is a substrate that is commonly used for light-control conductive films. The substrate 2 includes, for example, a transparent substrate 21 and cured resin layers 22 disposed on both sides of the transparent substrate 21 in the thickness direction.

[0026] The transparent substrate 21 has a film shape (including a sheet shape) and is, for example, a flexible polymer film.

[0027] Examples of materials for the transparent substrate 21 include 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. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include polyethylene, polypropylene, and cycloolefin polymer (COP). Examples of cellulose resins include triacetyl cellulose (TAC). From the viewpoints of transparency, heat resistance, mechanical strength, and the like, the transparent substrate 21 is preferably a polyester film. More preferably, it is a polyethylene terephthalate film. The materials for the transparent substrate 21 can be used alone or in combination.

[0028] The transparent substrate 21 has a visible light transmittance (JISK-7105) of, for example, 80% or more, preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more, and for example, 100% or less. Note that visible light transmittance is synonymous with total light transmittance (the same applies hereinafter).

[0029] From the viewpoint of strength and ease of handling, 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.

[0030] The thickness of the transparent substrate 21 can be measured using, for example, a film thickness meter.

[0031] 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 substrate 21 in the thickness direction, for example.

[0032] 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, makes the exposed surface of the light control conductive film 1 less susceptible to scratches. The anti-blocking layer imparts anti-blocking properties to the surfaces of the light control conductive films 1 that are in contact with each other, for example, when the light control conductive films 1 are stacked in the thickness direction.

[0033] 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 in the thickness direction of the transparent substrate 21, drying the composition as necessary, and then curing the composition.

[0034] The curable resin composition contains a curable resin. Examples of the curable resin include polyester resin, acrylic urethane resin, acrylic resin (excluding acrylic urethane resin), urethane resin (excluding acrylic urethane resin), amide resin, silicone resin, epoxy resin, and melamine resin. The curable resin can be used alone or in combination of two or more. Examples of the curable resin composition include ultraviolet-curable resin compositions and thermosetting resin compositions.

[0035] The curable resin composition may contain fine particles from the viewpoint of adjusting the hardness, surface roughness, refractive index, and anti-glare properties of the cured resin layer 22. Examples of the fine particles include inorganic particles (e.g., silica) and organic particles.

[0036] The curable resin composition may also contain additives such as a photopolymerization initiator, a solvent (for example, ethyl acetate, toluene), a leveling agent, a thixotropic agent, and an antistatic agent.

[0037] The thickness of the cured resin layer 22 is, for example, 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more, and for example, 15 μm or less, preferably 10 μm or less, more preferably 5 μm or less. The thickness of the cured resin layer 22 refers to the thickness of the cured resin layer 22 formed on either one surface or the other surface in the thickness direction of the transparent substrate 21, and is not the total thickness.

[0038] When the thickness of the cured resin layer 22 is equal to or greater than the above-mentioned 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 equal to or less than the above-mentioned upper limit, the light control conductive film 1 can be made thinner.

[0039] One surface in the thickness direction of the substrate 2 (the surface of the cured resin layer 22 that comes into contact with the blackened layer 3 or the metal oxide layer 5 described later) may be subjected to a surface modification treatment such as corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, saponification treatment, or treatment with a coupling agent, in order to improve adhesion to the blackened layer 3 or the metal oxide layer 5.

[0040] The visible light transmittance (JISK-7105) of the substrate 2 is, for example, 80% or more, preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more, and for example, 100% or less.

[0041] From the viewpoint of strength and ease of handling, 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.

[0042] <Blackened layer> The blackening layer 3 is disposed on one side in the thickness direction of the substrate 2. In the first embodiment, the blackening layer 3 contacts one surface of the substrate 2 in the thickness direction.

[0043] The blackening layer 3 has high light absorption properties, that is, the blackening layer 3 can adjust the visible light transmittance to an appropriate range.

[0044] The blackening layer 3 may contain, for example, an inorganic substance and may also contain an organic substance. From the viewpoint of light resistance, it preferably contains an inorganic substance and does not contain an organic substance. More preferably, it is made of an inorganic substance.

[0045] When an organic substance is contained, the blackening layer 3 contains, 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 examples thereof include carbon black.

[0046] When the blackening layer 3 does not contain an organic substance, it contains, for example, a metal (elementary metal) and a metal compound. Preferably, it contains an elemental metal and a metal oxide. The blackening layer 3 may contain multiple elemental metals or multiple metal compounds.

[0047] A metal compound is a compound of a metal and a nonmetal. 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. More preferably, it is In and Cu. That is, examples of metal compounds include indium oxide and copper oxide. The first metal can be used alone or in combination of two or more. Examples of copper oxide include copper(I) oxide and copper(II) oxide.

[0048] Examples of elemental metals (second metals) 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, it is Cu. The second metal may be the same as or different from the first metal. The second metals can be used alone or in combination of two or more.

[0049] The proportion of metal compounds in the blackened layer 3 is, for example, 70% by mass or more, preferably 80% by mass or more, more preferably 85% by mass or more, and for example, 99% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less.

[0050] 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.

[0051] When the proportion of the metal compound and the proportion of the elemental metal in the blackened layer 3 are within the above ranges, the visible light transmittance is excellent.

[0052] More preferably, the blackened layer 3 contains copper, copper oxide, and indium oxide. The blackened layer 3 may contain a trace amount of other metal compounds. Examples of the trace amount of other metal compounds include copper hydroxide.

[0053] If the blackened layer 3 contains the above-mentioned elemental metal and metal compound, it will have excellent visible light transmittance.

[0054] When the blackening layer 3 contains indium oxide, the proportion of In in the blackening layer 3 is, for example, 40 atomic % or more, or preferably 50 atomic % or more, and for example, 90 atomic % or less, or preferably 80 atomic % or less.

[0055] If the proportion of In in the blackened layer 3 is within the above range, the content of inorganic substances (for example, copper) with high light absorption properties can be sufficiently ensured.

[0056] 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.

[0057] If the proportion of Cu in the blackened layer 3 is within the above range, the visible light transmittance is excellent.

[0058] When the blackened layer 3 contains copper (elementary metal) and copper oxide, the proportion of the elemental metal Cu in the total amount of copper (elementary metal) and copper oxide is, for example, 50 atomic % or more, preferably 60 atomic % or more, and for example, 90 atomic % or less, preferably 80 atomic % or less.

[0059] When the blackened layer 3 contains copper (single metal) and copper oxide, the proportion of Cu in the copper oxide in the total amount of copper (single 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.

[0060] When the blackened layer 3 contains copper oxide, the proportion of Cu in copper (I) oxide in the total amount of copper (element 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.

[0061] When the blackened layer 3 contains copper oxide, the proportion of Cu in copper (II) oxide in the total amount of copper (element 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.

[0062] When the proportion of Cu in the elemental metal and the proportion of Cu in the copper oxide (the proportion of Cu in copper(I) oxide and the proportion of Cu in copper(II) oxide) in the total amount of copper (elemental metal) and copper oxide are within the above ranges, the visible light transmittance is excellent.

[0063] The thickness of the blackening layer 3 is, for example, 1 nm to 40 nm, preferably 3 nm to 38 nm, more preferably 5 nm to 35 nm, and still more preferably 10 nm to 35 nm.

[0064] The thickness of the blackening layer 3 is, for example, 1 nm or more, preferably 3 nm or more, more preferably 5 nm or more, and even more preferably 10 nm or more, and for example, less than 40 nm, preferably 38 nm or less, and more preferably 35 nm or less.

[0065] When the thickness of the blackened layer 3 is equal to or greater than the above lower limit, the visible light transmittance is excellent. When the thickness of the blackened layer 3 is equal to or less than 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 visible light transmittance can be prevented.

[0066] The visible light transmittance (JISK-7105) of the blackened layer 3 is, for example, 35% or more and, for example, 90% or less.

[0067] The luminous transmittance (Y value) of the blackened layer 3 in the wavelength range of 380 nm to 780 nm in the CIE-XYZ color system is, for example, 0.001% to 0.1%, preferably 0.005% to 0.05%, and more preferably 0.01% to 0.03%. The luminous transmittance can be measured, for example, by a spectrophotometer (product name: U-4100, manufactured by Hitachi High-Tech Science Corporation).

[0068] <Inorganic layer> The inorganic layer 4 is disposed on one thickness-wise side of the blackening layer 3. Preferably, it is disposed on one thickness-wise surface of the blackening layer 3. In other words, the inorganic layer 4 is preferably in contact with one thickness-wise surface of the blackening layer 3.

[0069] The inorganic layer 4 includes, in order toward one side in the thickness direction, a first transparent conductive layer 41, a metal layer 42, and a second transparent conductive layer 43. That is, the inorganic layer 4 includes the first transparent conductive layer 41, the metal layer 42 disposed on one surface in the thickness direction of the first transparent conductive layer 41, and the second transparent conductive layer 43 disposed on one surface in the thickness direction of the metal layer 42.

[0070] The inorganic layer 4 is, for example, a layer formed by a dry coating method (dry coating layer). Examples of dry coating layers include a sputtered layer formed by a sputtering method and a vapor deposition layer formed by a vapor deposition method. A sputtered layer is preferred. That is, the first transparent conductive layer 41, the metal layer 42, and the second transparent conductive layer 43 are preferably sputtered layers.

[0071] [First transparent conductive layer] The first transparent conductive layer 41 is disposed on one side in the thickness direction of the blackening layer 3. Preferably, it is disposed on one surface in the thickness direction of the blackening layer 3. In other words, the first transparent conductive layer 41 is preferably in contact with one surface in the thickness direction of the blackening layer 3.

[0072] By disposing the first transparent conductive layer 41 on one surface in the thickness direction of the blackening layer 3, the metal layer 42 and the blackening layer 3 do not come into direct contact with each other, thereby suppressing discoloration of the metal layer 42. As a result, the visible light transmittance is excellent.

[0073] Examples of the first transparent conductive layer 41 include a metal layer and a metal oxide layer. A metal oxide layer is preferred. Examples of metals in the metal oxides that form the first transparent conductive layer 41 include indium (In), zinc (Zn), tin (Sn), magnesium (Mg), nickel (Ni), cobalt (Co), and chromium (Cr). A more preferred example of the first transparent conductive layer 41 is an indium tin composite oxide layer (ITO layer).

[0074] When the first transparent conductive layer 41 is an ITO layer, the ratio of tin oxide to the total content of indium oxide (In2O3) and tin oxide (SnO2) in the ITO layer 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.

[0075] If 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.

[0076] 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 for example, 200 nm or less, preferably 100 nm or less, more preferably 50 nm or less.

[0077] When the thickness of the first transparent conductive layer 41 is equal to or greater than the above-mentioned lower limit, the resistance value can be appropriately reduced. When the thickness of the first transparent conductive layer 41 is equal to or less than the above-mentioned upper limit, the adhesion of the first transparent conductive layer 41 to the blackening layer 3 is excellent, and the light-control conductive film 1 can be made thinner.

[0078] [Metal layer] 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.

[0079] The metal layer 42 is formed from, for example, a metal that has light reflectivity (excellent solar reflectance).

[0080] Examples of metals that form the metal layer 42 include aluminum (Al), silver (Ag), titanium (Ti), and alloys thereof. From the viewpoint of good optical reflectivity for visible light, Al, Ag, and alloys thereof are preferred. Ag and silver alloys are more preferred. That is, examples of the metal layer 42 include a silver layer and a silver alloy layer.

[0081] 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 still more preferably 5 nm to 10 nm.

[0082] 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 for example, 30 nm or less, preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less.

[0083] When the thickness of the metal layer 42 is equal to or greater than the above lower limit, the solar reflectance is excellent. When the thickness of the metal layer 42 is equal to or less than the above upper limit, the resistance value can be prevented from becoming excessively low.

[0084] [Second transparent conductive layer] The second transparent conductive layer 43 is disposed, for example, on one thickness-wise side of the metal layer 42. Preferably, it is disposed on one thickness-wise surface of the metal layer 42. In other words, the second transparent conductive layer 43 contacts one thickness-wise surface of the metal layer 42.

[0085] Examples of the second transparent conductive layer 43 include a metal layer, a metal oxide layer, and a metal nitride layer. A metal oxide layer is preferred. Examples of metals in the metal oxides that form the second transparent conductive layer 43 include indium (In), zinc (Zn), tin (Sn), magnesium (Mg), nickel (Ni), cobalt (Co), and chromium (Cr). A preferred example of the second transparent conductive layer 43 is an ITO layer.

[0086] When the second transparent conductive layer 43 is an ITO layer, the ratio of tin oxide to the total content of indium oxide (In2O3) and tin oxide (SnO2) in the ITO layer 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.

[0087] If 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.

[0088] The second transparent conductive layer 43 has a thickness of, for example, 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more, and for example, 200 nm or less, preferably 100 nm or less, more preferably 50 nm or less.

[0089] When the thickness of the second transparent conductive layer 43 is equal to or greater than the above lower limit, the resistance can be appropriately reduced. When the thickness of the second transparent conductive layer 43 is equal to or less than the above upper limit, the adhesion of the second transparent conductive layer 43 to the metal layer 42 is excellent, and the light control conductive film 1 can be made thinner.

[0090] The total thickness of the inorganic layer 4 (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 for example, 500 nm or less, preferably 300 nm or less, more preferably 200 nm or less, and even more preferably 100 nm or less.

[0091] When the thickness of the inorganic layer 4 is equal to or greater than the above lower limit, the resistance value can be appropriately reduced. When the thickness of the inorganic layer 4 is equal to or less than the above upper limit, the light-control conductive film 1 can be made thinner.

[0092] The visible light transmittance (JISK-7105) of the inorganic layer 4 is, for example, 70% or more and, for example, 99% or less.

[0093] The thickness ratio of the metal layer 42 to 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.

[0094] When the ratio of the thickness of the metal layer 42 to the inorganic layer 4 is equal to or greater than the above lower limit, the solar reflectance is excellent. When the ratio of the thickness of the metal layer 42 to the inorganic layer 4 is equal to or less than the above upper limit, the resistance value can be prevented from becoming excessively low.

[0095] The thickness ratio of the blackening layer 3 to the thickness of the inorganic layer 4 (thickness of the blackening layer 3 / thickness of the inorganic layer 4) is, for example, 0.01 or more, preferably 0.03 or more, more preferably 0.05 or more, and for example, 0.5 or less, preferably 0.4 or less, more preferably 0.2 or less, and even more preferably 0.1 or less.

[0096] When the ratio of the thickness of the blackening layer 3 to the thickness of the inorganic layer 4 is within the above range, the visible light transmittance is excellent.

[0097] From the viewpoints of strength and ease of handling, the thickness of the light control 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.

[0098] The resistance value (surface resistance) of the light control conductive film 1 is, for example, 6Ω / □ to 15Ω / □, preferably 8Ω / □ to 14Ω / □, and more preferably 10Ω / □ to 13Ω / □.

[0099] The resistance value (surface resistance) of the light-control conductive film 1 is, for example, 6 Ω / □ or more, preferably 8 Ω / □ or more, more preferably 10 Ω / □ or more, and for example, 15 Ω / □ or less, preferably 14 Ω / □ or less, more preferably 13 Ω / □ or less.

[0100] If the resistance value (surface resistance) of the light-control conductive film 1 is equal to or greater than the above lower limit, the risk of short circuiting can be reduced. If the resistance value (surface resistance) of the light-control conductive film 1 is equal to or less than the above upper limit, the conductive film 1 has excellent conductivity.

[0101] The resistance value (surface resistance) of the light-control conductive film 1 can be measured by a four-terminal method in accordance with JIS K 7194 (1994), as will be specifically shown in the examples below.

[0102] The resistance value (surface resistance) of the light-control conductive film 1 can be adjusted by the thickness and material of the blackening 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.

[0103] 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%.

[0104] 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, more preferably 70% or less.

[0105] If the visible light transmittance of the light control conductive film 1 is within the above range, the light control function (difference in contrast between the light blocking mode and the transmission mode) can be sufficiently ensured.

[0106] The visible light transmittance of the light control conductive film 1 can be measured using a haze meter in accordance with JIS K 7375 (2008), as specifically described in the examples below.

[0107] The visible light transmittance of the light-control conductive film 1 can be adjusted by the thickness and material of the blackening layer 3, the total thickness and material of the inorganic layer 4, and the thickness of each layer constituting the inorganic layer 4. In particular, the visible light transmittance can be adjusted by the thickness and material of the blackening layer 3.

[0108] The solar reflectance of the light control conductive film 1 is, for example, 33% or more, preferably 34% or more, or more preferably 35% or more.

[0109] The solar reflectance of the light control conductive film 1 can be calculated by the following formula (1) with reference to ISO13837: R λ indicates spectral reflectance, which can be measured using a spectrophotometer. Specific examples will be described later.

number

[0110] The solar reflectance of the light-control conductive film 1 can be adjusted by the total thickness of the inorganic layer 4, the material thereof, 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.

[0111] The rate of change in visible light transmittance of the light control conductive film 1 under high temperature and high humidity conditions is, for example, 15% or less, preferably 10% or less, more preferably 5% or less, even more preferably 3% or less, and particularly preferably 1% or less.

[0112] When the rate of change in visible light transmittance in the light control conductive film 1 under high temperature and high humidity conditions is equal to or less than the upper limit, the film has excellent reliability.

[0113] The rate of change in visible light transmittance of the light-control conductive film 1 under a high-temperature and high-humidity environment can be determined by the method shown in the examples described later.

[0114] The rate of change in visible light transmittance of the light-control conductive film 1 under a high-temperature, high-humidity environment can be adjusted by the thickness and material of the blackening layer 3, the total thickness and material of the inorganic layer 4, the thickness of each layer constituting the inorganic layer 4, and the thickness and configuration of the metal oxide layer 5 described below.

[0115] 2. Second embodiment A second embodiment of the light control conductive film of the present invention will be described with reference to Fig. 2. Note that the same configuration as in the first embodiment will be omitted.

[0116] The light-control conductive film 1 includes a substrate 2, a blackening layer 3, and an inorganic layer 4, arranged in this order toward one side in the thickness direction. The light-control conductive film 1 further includes a metal oxide layer 5 between the substrate 2 and the blackening layer 3. That is, the light-control conductive film 1 includes the metal oxide layer 5 disposed on one side of the substrate 2 in the thickness direction, the blackening layer 3 disposed on one side of the metal oxide layer 5 in the thickness direction, and the inorganic layer 4 disposed on one side of the blackening layer 3 in the thickness direction. Specifically, as shown in FIG. 2 , the light-control conductive film 1 of the second embodiment includes the substrate 2, the metal oxide layer 5 disposed on one surface of the substrate 2 in the thickness direction, the blackening layer 3 disposed on one surface of the metal oxide layer 5 in the thickness direction, and the inorganic layer 4 disposed on one surface of the blackening layer 3 in the thickness direction. The light-control conductive film 1 may also include a protective film 23 and an adhesive layer 24 (see FIG. 4C ) on the other side of the substrate 2 in the thickness direction. The protective film 23 and the adhesive layer 24 are peeled off from the light-control conductive film 1 at a predetermined timing.

[0117] When the light-control conductive film 1 has the layer structure described above, the visible light transmittance can be adjusted by the blackening layer 3, and further, the metal layer 42 of the inorganic layer 4 can reflect light in the long wavelength region before it is absorbed by the blackening layer 3. In other words, the light-control conductive film 1 has excellent solar reflectance. As a result, the light-control conductive film 1 has excellent heat-shielding properties. In addition, the light-control conductive film 1 further includes a metal oxide layer 5 between the substrate 2 and the blackening layer 3. This further suppresses changes in visible light transmittance in high-temperature, high-humidity environments. Specifically, the metal oxide layer 5 can suppress an increase in the visible light transmittance of the blackening layer (more specifically, an increase in the proportion of copper(II) oxide among the copper atoms contained in the blackening layer) due to the influence of outgassing from the substrate 2 in high-temperature, high-humidity environments. As a result, the light-control conductive film 1 has even better reliability.

[0118] <Metal oxide layer> The metal oxide layer 5 is disposed between the substrate 2 and the blackening layer 3. That is, the metal oxide layer 5 preferably contacts one surface of the substrate 2 in the thickness direction and the other surface of the blackening layer 3 in the thickness direction.

[0119] The metal oxide layer 5 is, for example, a layer formed by a dry coating method (dry coating layer). Examples of the dry coating layer include a sputtered layer formed by a sputtering method and a vapor deposition layer formed by a vapor deposition method. A sputtered layer is preferred.

[0120] Examples of the metal oxide layer 5 include a metal layer and a metal oxide layer. A metal oxide layer is preferred. Examples of metals in the metal oxides that form the metal oxide layer 5 include indium (In), zinc (Zn), tin (Sn), magnesium (Mg), nickel (Ni), cobalt (Co), and chromium (Cr). A more preferred example of the metal oxide layer 5 is an indium tin composite oxide layer (ITO layer).

[0121] When the metal oxide layer 5 is an ITO layer, the ratio of tin oxide to the total content of indium oxide (In2O3) and tin oxide (SnO2) in the ITO layer 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.

[0122] If 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.

[0123] 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.

[0124] 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 still more preferably 3 nm to 10 nm.

[0125] 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, even more preferably 3 nm or more, and for example, 80 nm or less, preferably less than 40 nm, more preferably 20 nm or less, even more preferably 10 nm or less, and particularly preferably 6 nm or less.

[0126] When the thickness of the metal oxide layer 5 is equal to or greater than the above lower limit, the change in visible light transmittance in a high-temperature, high-humidity environment can be suppressed. As a result, reliability is further improved. Furthermore, when the thickness of the metal oxide layer 5 is equal to or less than the above upper limit, the adhesion of the metal oxide layer 5 to the substrate 2 is excellent, and the light-control conductive film 1 can be made thinner.

[0127] The light control conductive film 1 is suitable for use in automobile sunroofs and the like.

[0128] 3. Manufacturing method of light-control conductive film <Method for manufacturing the light control conductive film of the first embodiment> 3A to 3B, a method for producing the light control conductive film 1 of the first embodiment will be described. The light control conductive film 1 is produced, for example, by a roll-to-roll method as follows.

[0129] FIG. 3A shows a step of preparing a substrate with a protective film (preparation step), and FIG. 3B shows a step of forming a blackening layer 3 and an inorganic layer 4 on the substrate with a protective film (lamination step).

[0130] (Preparation process) As shown in Fig. 3A, a substrate with a protective film is prepared. Specifically, first, a transparent substrate 21 is prepared, and a curable resin composition is applied to both surfaces of the transparent substrate 21 in the thickness direction, and then dried as necessary and cured to form a cured resin layer 22. In this manner, the substrate 2 is obtained.

[0131] Next, the protective film 23 is bonded to the other thickness-wise surface of the substrate 2. Specifically, one thickness-wise surface of the single-sided adhesive protective film is bonded to the other thickness-wise surface of the substrate 2. The single-sided adhesive protective film includes the protective film 23 and an adhesive layer 24 on one thickness-wise surface of the protective film 23. For example, a roll-to-roll laminating device is used to bond the substrate 2 and the single-sided adhesive protective film.

[0132] [Protection film] The protective film 23 is a film for preventing scratches on the light control conductive film 1. The protective film 23 is peeled off together with the adhesive layer 24 from the light control conductive film 1 at a predetermined timing.

[0133] The protective film 23 has a film shape (including a sheet shape) and is, for example, a flexible polymer film.

[0134] 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, and the like, the protective film 23 is preferably a polyester film, more preferably a polyethylene terephthalate film.

[0135] From the viewpoints of strength and ease of handling, the thickness of the protective film 23 is thicker than the thickness of the transparent substrate 21, for example, 50 μm or more, preferably 100 μm or more, and for example, 500 μm or less, preferably 300 μm or less.

[0136] The thickness of the protective film 23 can be measured using, for example, a film thickness meter.

[0137] [Adhesive layer] The adhesive layer 24 is a layer that bonds the base material 2 and the protective film 23. That is, the adhesive layer 24 contacts one surface of the protective film 23 in the thickness direction and contacts the other surface of the base material 2 in the thickness direction.

[0138] The adhesive layer 24 is, for example, a layer made of an adhesive, and is formed by applying an adhesive to one surface in the thickness direction of the protective film 23. The adhesive is not particularly limited as long as it is commonly used in light-control conductive films and allows the protective film 23 to be peeled off at a predetermined timing, and examples thereof include acrylic adhesives.

[0139] In order to ensure adhesiveness, the adhesive layer 24 has a thickness of, for example, 5 μm or more, or preferably 10 μm or more, and for example, 50 μm or less, or preferably 40 μm or less.

[0140] The other thickness-wise surface of the substrate 2 is bonded to one thickness-wise surface of the single-sided adhesive protective film (one thickness-wise surface of the adhesive layer 24), thereby obtaining a substrate with a protective film.

[0141] (Lamination process) 3B, a blackening layer 3 and an inorganic layer 4 are formed on one surface in the thickness direction of the substrate with the protective film (one surface in the thickness direction of the substrate 2). Specifically, the blackening layer 3 is formed on one surface in the thickness direction of the substrate with the protective film, and then the inorganic layer 4 is formed on one surface in the thickness direction of the blackening layer 3. The inorganic layer 4 is formed by forming 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.

[0142] The blackening 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 dipole sputtering, ECR (electron cyclotron resonance) sputtering, magnetron sputtering, and ion beam sputtering. Magnetron sputtering is preferred.

[0143] In the sputtering method, for example, a sputtering deposition apparatus is used. The sputtering deposition apparatus can perform the deposition process using a roll-to-roll method. In the blackening layer and inorganic layer formation process, a long substrate with a protective film is used as a work film and is run from a pay-out roll to a take-up roll, while the materials for the blackening layer 3 and inorganic layer 4 are sequentially formed on one side of the substrate with the protective film in the thickness direction. The running speed of the work film is, for example, 0.5 m / min to 10.0 m / min.

[0144] The sputtering method may use a sputtering deposition apparatus with a single deposition chamber, or a sputtering deposition apparatus with multiple deposition chambers arranged in sequence along the workpiece film's travel path. When the blackening layer 3 and inorganic layer 4 are sequentially deposited, a sputtering deposition apparatus with multiple deposition chambers arranged in sequence along the workpiece film's travel path is preferably used. By performing the entire process of forming the blackening layer 3 and inorganic layer 4 on a single path, the workpiece film is not exposed to the atmosphere during the process. This improves adhesion between each layer.

[0145] Specifically, in the sputtering method, a sputtering gas (inert gas) is introduced into each deposition chamber of the sputter deposition apparatus under vacuum conditions, while a negative voltage is applied to a target placed on a cathode in each deposition chamber. This generates a glow discharge, ionizing the gas atoms, causing these gas ions to collide with the target surface at high speed, ejecting target material from the target surface, and the ejected target material is then deposited in sequence on the substrate 2.

[0146] Examples of sputtering gases include argon, krypton, xenon, and mixed gases thereof, preferably argon. A reactive gas (e.g., oxygen) can also be used in combination. When a reactive gas is used in combination, the amount of the gas introduced is set to satisfy the partial pressure of the reactive gas described below.

[0147] The pressure in the film formation chamber during film formation by sputtering (sputter film formation) (the pressure in the film formation chamber when the sputtering gas, or the sputtering gas and reactive gas are introduced) is, for example, 0.02 Pa to 1 Pa, preferably 0.1 Pa to 0.6 Pa.

[0148] When a reactive gas is used in combination, the partial pressure of the reactive gas in the deposition chamber is, for example, 1.0×10 -4 Pa~1.0×10 -2 It is Pa.

[0149] Examples of the power source for applying a voltage to the target include a DC power source, an AC power source, an MF power source, and an RF power source, and preferably a DC power source.

[0150] The film formation temperature during sputtering (temperature of the work film during film formation) is, for example, 100°C or less, preferably 50°C or less, more preferably 0°C or less, even more preferably -5°C or less, and, for example, -20°C or more.

[0151] Examples of target materials disposed on the cathode in the film formation chamber include the materials for the blackening layer 3 and inorganic layer 4 described above. Specifically, examples of target materials for forming the blackening layer 3 include metals and metal oxides, preferably copper and indium oxide. Examples of target materials for forming the first transparent conductive layer 41 and the second transparent conductive layer 43 include metal oxides, preferably indium tin oxide (ITO). Examples of target materials for forming the metal layer 42 include metals with optical reflectivity (excellent solar reflectance), preferably silver and silver alloys. Note that if copper is used as the elemental metal for the target material for forming the blackening layer 3, a portion of the copper elemental metal will become copper oxide during and / or after film formation.

[0152] In this manner, a light control conductive film with a protective film is obtained in which the protective film 23 is attached to the light control conductive film 1 of the first embodiment.

[0153] The protective film 23 is peeled off together with the adhesive layer 24 from the light-control conductive film 1 at a predetermined timing. Specifically, the protective film 23 and the adhesive layer 24 are peeled off immediately before the light-control conductive film 1 is used.

[0154] <Method for manufacturing the light control conductive film according to the second embodiment> 4A to 4C, a method for producing the light control conductive film 1 of the second embodiment will be described. The light control conductive film 1 is produced, for example, by a roll-to-roll method as follows.

[0155] Figure 4A shows a process of preparing a substrate with a protective film (preparation process), Figure 4B shows a process of forming a metal oxide layer 5 on the substrate with a protective film (metal oxide layer formation process), and Figure 4C shows a process of forming a blackening layer 3 and an inorganic layer 4 on the metal oxide layer 5 (lamination process).

[0156] (Preparation process) 4A, a substrate with a protective film is prepared, specifically in the same manner as the preparation step in the method for producing the light-control conductive film 1 of the first embodiment.

[0157] (Metal oxide layer process) Next, after the preparation step and before the lamination step, a metal oxide layer forming step is carried out. Specifically, as shown in Fig. 4B, a metal oxide layer 5 is formed on one surface in the thickness direction of the substrate with the protective film.

[0158] The metal oxide layer 5 is formed by, for example, a dry coating method. Examples of dry coating methods include sputtering and vapor deposition. Preferably, sputtering is used. Examples of sputtering methods include the same methods as those used in the lamination step in the manufacturing method of the light control conductive film 1 of the first embodiment. Preferably, magnetron sputtering is used.

[0159] In the sputtering method, for example, a sputtering film-forming apparatus is used, and the same procedures and conditions as those in the lamination step in the manufacturing method for the light-control conductive film 1 of the first embodiment can be used. Note that examples of the material of the target placed on the cathode in the film-forming chamber include the above-mentioned material of the metal oxide layer 5. Specifically, examples of the target material for forming the metal oxide layer 5 include metal oxides, and preferably indium tin oxide (ITO).

[0160] The metal oxide layer 5 may be formed using a sputtering deposition apparatus with a single deposition chamber, or a sputtering deposition apparatus with multiple deposition chambers arranged in sequence along the workpiece film's travel path. When the metal oxide layer 5, blackened layer 3, and inorganic layer 4 are sequentially deposited, a sputtering deposition apparatus with multiple deposition chambers arranged in sequence along the workpiece film's travel path is preferably used. By performing the series of processes of forming the metal oxide layer 5, blackened layer 3, and inorganic layer 4 on a single path, the workpiece film is not exposed to the atmosphere during the process. This improves adhesion between each layer.

[0161] (Lamination process) 4C, a blackening layer 3 is formed on one thickness-wise surface of the metal oxide layer 5, and an inorganic layer 4 is formed on one thickness-wise surface of the blackening layer 3. Specifically, this is the same as the lamination step in the method for producing the light-control conductive film 1 of the first embodiment.

[0162] In this manner, a light control conductive film with a protective film is obtained in which the protective film 23 is attached to the light control conductive film 1 of the second embodiment.

[0163] The protective film 23 is peeled off together with the adhesive layer 24 from the light-control conductive film 1 at a predetermined timing. Specifically, the protective film 23 and the adhesive layer 24 are peeled off immediately before the light-control conductive film 1 is used.

[0164] (Action and effect) The light-control conductive film of the present invention includes a substrate, a blackening layer, and an inorganic layer, arranged in this order toward one side in the thickness direction, and the inorganic layer includes a first transparent conductive layer, a metal layer, and a second transparent conductive layer, arranged in this order toward one side in the thickness direction, thereby preventing an excessive decrease in resistance, and providing excellent transmittance for light in the visible light range and excellent reflectance for light in the long wavelength range. [Example]

[0165] The present invention will be described in more detail below with reference to examples and comparative examples. It should be noted that the present invention is not limited to these examples and comparative examples. The specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be substituted with the upper limit (a numerical value defined as "equal to or less than") or lower limit (a numerical value defined as "equal to or more than" or "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the "Description of the Invention" above.

[0166] Example 1 (Preparation process) A substrate was prepared, which included a 2 μm-thick curable resin layer on both thickness-wise sides of a polyethylene terephthalate (PET) film (thickness: 50 μm, manufactured by Toray Industries, Inc.) as a transparent substrate. A single-sided adhesive protective film (thickness: 145 μm, manufactured by Nitto Denko Corporation) was also prepared. The single-sided adhesive protective film included a protective film (thickness: 125 μm, PET film) and an adhesive layer (thickness: 20 μm) made of an acrylic adhesive formed on one thickness-wise side of the protective film. The substrate and the single-sided adhesive protective film were then placed in a roll-to-roll laminating device, and the other thickness-wise side of the substrate was bonded to one thickness-wise side of the single-sided adhesive protective film (one thickness-wise side of the adhesive layer). In this manner, a substrate with a protective film was produced.

[0167] (Lamination process) Next, a blackening layer and an inorganic layer (a first transparent conductive layer, a metal layer, and a second transparent conductive layer) were formed by sputtering on one thickness-wise surface of the substrate with the protective film (one thickness-wise surface of the substrate). A roll-to-roll sputtering deposition apparatus (DC magnetron sputtering deposition apparatus) was used for the sputtering. This sputtering deposition apparatus includes a payout chamber, multiple deposition chambers, and a take-up chamber. The payout chamber includes a payout roller. A roll of the above-mentioned substrate was set on the payout roller as a work film. The take-up chamber includes a take-up roller capable of taking up the work film. In the multiple deposition chambers, each layer can be deposited while the work film is run from the payout chamber to the take-up chamber using a roll-to-roll method.

[0168] Specifically, the workpiece film (substrate) was unwound from the unwinding chamber, and then an 8 nm thick blackening layer, a 40 nm thick first transparent conductive layer, an 8 nm thick metal layer, and a 40 nm thick second transparent conductive layer were sequentially deposited.The workpiece film (single-sided adhesive protective film / substrate / blackening layer / first transparent conductive layer / metal layer / second transparent conductive layer) was then wound up on the winding roller in the winding chamber.Details of the sputtering conditions for each layer are shown below.

[0169] In forming the blackening layer, the inside of the sputtering film-forming apparatus was evacuated, and then argon (Ar) as a sputtering gas and oxygen as a reactive gas were introduced into the film-forming chamber, and the pressure inside the film-forming chamber was set to 0.2 Pa. The partial pressure of oxygen was about 7.0 × 10 -4 The pressure was 100 Pa. A sintered body of indium oxide (In2O3) and copper (Cu) (manufactured by Mitsui Kinzoku Co., Ltd.) was used as the 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 blackening layer is laminated) was -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.

[0170] In forming the first transparent conductive layer, the sputtering apparatus was evacuated, and then Ar as a sputtering gas and oxygen as a reactive gas were introduced into the chamber, and the pressure in the chamber was set to 0.2 Pa. The partial pressure of oxygen was about 5.0 × 10 -3 The density was Pa. As the target, a sintered body of indium oxide and tin oxide (tin oxide concentration: 12.5 mass %) was used.

[0171] In forming the metal layer, the sputtering deposition apparatus was evacuated, and then Ar was introduced into the deposition chamber as a sputtering gas, and the pressure in the deposition chamber was set to 0.3 Pa. A silver alloy (product number: No. 317, manufactured by Mitsubishi Materials Corporation) was used as the target.

[0172] In forming the second transparent conductive layer, the sputtering apparatus was evacuated, and then Ar as a sputtering gas and oxygen as a reactive gas were introduced into the chamber, and the pressure in the chamber was set to 0.2 Pa. The partial pressure of oxygen was about 5.0 × 10 -3 The density was Pa. As the target, a sintered body of indium oxide and tin oxide (tin oxide concentration: 12.5 mass %) was used.

[0173] A light-control conductive film with a protective film was produced as described above, and the one-sided adhesive protective film was peeled off to obtain the light-control conductive film of Example 1. The light-control conductive film of Example 1 comprises, in order toward 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). Note that, for each of the following evaluations, the light-control conductive film after peeling off the one-sided adhesive protective film was used (the same applies hereinafter).

[0174] Example 2 Except for the fact that the thickness of the blackening layer was set to 32 nm, the light control conductive film of Example 2 was produced in the same manner as the light control conductive film of Example 1. That is, the light control conductive film of Example 2 includes, in order toward one side in the thickness direction, a substrate (thickness: 54 μm), 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).

[0175] Comparative Example 1 The light-modulating conductive film of Comparative Example 1 was produced in the same manner as the light-modulating conductive film of Example 1, except that no blackening layer was formed. That is, an inorganic layer (specifically, a first transparent conductive layer) was formed on one thickness-wise surface of the substrate. The light-modulating conductive film of Comparative Example 1 includes, in order toward one thickness-wise side, 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).

[0176] Comparative Example 2 Except for the fact that the thickness of the silver alloy layer was set to 18 nm, the light-control conductive film of Comparative Example 2 was produced in the same manner as the light-control conductive film of Comparative Example 1. The light-control conductive film of Comparative Example 2 includes, 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: 18 nm), and a second transparent conductive layer (ITO layer, thickness: 40 nm).

[0177] Comparative Example 3 Except for the fact that the thickness of the silver alloy layer was set to 30 nm, the light-control conductive film of Comparative Example 3 was produced in the same manner as the light-control conductive film of Comparative Example 1. The light-control conductive film of Comparative Example 3 includes, 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: 30 nm), and a second transparent conductive layer (ITO layer, thickness: 40 nm).

[0178] Comparative Example 4 The light-modulating conductive film of Comparative Example 4 was produced in the same manner as the light-modulating conductive film of Comparative Example 1, except that a 6-nm-thick blackened layer was formed on one thickness-wise surface of the second transparent conductive layer. The conditions for forming the blackened layer were the same as those described above. That is, an inorganic layer (specifically, the first transparent conductive layer) was formed on one thickness-wise surface of the substrate, and a blackened layer was formed on one thickness-wise surface of the inorganic layer (specifically, the second transparent conductive layer). The light-modulating conductive film of Comparative Example 4 includes, in order toward one thickness-wise side, 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: 6 nm).

[0179] Comparative Example 5 Except for the fact that the thickness of the blackening layer was set to 32 nm, the light-control conductive film of Comparative Example 5 was produced in the same manner as the light-control conductive film of Comparative Example 4. That is, the light-control conductive film of Comparative Example 5 includes, 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: 32 nm).

[0180] Example 3 The light-control conductive film of Example 3 was produced in the same manner as the light-control conductive film of Example 1, except for the following: After the preparation step and before the lamination step, a metal oxide layer having a thickness of 4 nm was formed by sputtering on one surface in the thickness direction of the substrate with the protective film (one surface in the thickness direction of the substrate). Specifically, the same roll-to-roll sputtering deposition apparatus as in the lamination step was used. The details of the sputtering conditions for the metal oxide layer are shown below.

[0181] After evacuating the inside of the sputtering film-forming apparatus, Ar as a sputtering gas and oxygen as a reactive gas were introduced into the film-forming chamber, and the pressure inside the film-forming chamber was set to 0.2 Pa. The partial pressure of oxygen was about 5.0 × 10 -3The deposition temperature was -8°C. A sintered body of indium oxide and tin oxide (tin oxide concentration: 12.5% ​​by mass) was used as the target. A DC power supply was used as the power source for applying voltage to the target. The deposition temperature (the temperature of the substrate with the protective film on which the metal oxide layer is laminated) was -8°C.

[0182] In this way, a metal oxide layer was formed on one surface in the thickness direction of the substrate with the protective film. Thereafter, the lamination step described above was carried out. Note that the metal oxide layer forming step and the lamination step were carried out continuously.

[0183] That is, the light-control 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).

[0184] Example 4 Except for the fact that the thickness of the metal oxide layer was 8 nm, the light control conductive film of Example 4 was produced in the same manner as the light control conductive film of Example 3. That is, the light control conductive film of Example 4 includes, in order toward 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).

[0185] <Evaluation> [Resistance value] The resistance values ​​(surface resistance) of the light-control conductive films of Examples 1 and 2 and each comparative example were measured by 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. {standard} ○: 6Ω / □ or more ×: Less than 6Ω / □

[0186] [Visible light transmittance (total light transmittance)] 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 Instruments Co., Ltd.) in accordance with JIS K 7375 (2008) 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. {standard} ◎: 30% or more, 70% or less ○: More than 70%, less than 80% ×: Less than 30% or more than 80%

[0187] [Solar reflectance] The solar reflectance Re of the light control conductive films of Examples 1 and 2 and each comparative example was calculated by the above formula (1) with reference to ISO13837, and evaluated according to the following criteria. The results are shown in Table 1. λ was measured using a spectrophotometer (product name: U4100, manufactured by Hitachi High-Technologies Corporation). {standard} ◎: 35% or more ○: 33% or more, less than 35% ×: Less than 33%

[0188] [Reliability evaluation] The light-control conductive films of Examples 1, 3, and 4 were cut into 5 cm square pieces. Furthermore, a 5 cm square glass plate (thickness: 1.3 mm) was prepared by laminating an OCA (Optical Clear Adhesive) (product name: LUCIACS CS9861UAS, manufactured by Nitto Denko Corporation). Each 5 cm square light-control conductive film was laminated so that one thickness-wise side (one thickness-wise side of the second transparent conductive layer) faced the OCA, to prepare a sample. The initial visible light transmittance (initial visible light transmittance) of the sample was then 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 using the following formula and evaluated according to the following criteria. The results are shown in Table 2. Change rate (%) = |(visible light transmittance after 240 hours) - (initial visible light transmittance)| / (initial visible light transmittance) {standard} ○: Less than 3% △: 3% or more, 15% or less ×: Exceeding 15%

[0189] [Table 1]

[0190] [Table 2] [Explanation of symbols]

[0191] 1. Light-control conductive film 2 Base material 3 Blackened layer 4 Inorganic layer 41 First transparent conductive layer 42 Metal layer 43 Second transparent conductive layer

Claims

1. a substrate, a blackening layer, and an inorganic layer in this order toward one side in a thickness direction; The light-control conductive film, wherein the inorganic layer includes a first transparent conductive layer, a metal layer, and a second transparent conductive layer in this order toward one side in the thickness direction.

2. The light-control conductive film according to claim 1 , further comprising a metal oxide layer between the substrate and the blackening layer.

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

4. The light-control conductive film according to claim 2 , wherein the metal oxide layer has a thickness of 1 nm or more and less than 40 nm.

5. the first transparent conductive layer and the second transparent conductive layer are indium tin composite oxide layers, The light-control conductive film according to any one of claims 1 to 4, wherein the metal layer is a silver alloy layer.

6. The light-control conductive film according to any one of claims 1 to 4, wherein the blackening layer contains a metal and a metal oxide.

7. The light-control conductive film according to claim 6 , wherein the blackening layer contains 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 blackening layer is 1 nm or more and less than 40 nm.

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

10. The light-control conductive film according to any one of claims 1 to 4, having a solar reflectance of 33% or more.

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