Dimming film

Abstract

This dimming film (X) is provided with a base film (10), an electrode layer (20), a dimming layer (30), and an electrode layer (40) in this order in the thickness direction (H). The electrode layer (20) is an indium-tin composite oxide layer having a tin oxide ratio of 11% by mass or more. The electrode layer (20) has a carrier number of 10 * 1015 cm <-2 > or more.

Description

Technical Field

[0001] The invention relates to a dimming film. Background Art

[0002] A dimming film is known for being applied to window glass in buildings, vehicles, and the like. The dimming film includes a dimming portion and a transparent base film supporting the dimming portion. The dimming portion includes, for example, a transparent conductive layer, a dimming layer, and a transparent conductive layer in this order in the thickness direction. The dimming layer is sandwiched between two transparent conductive layers. The dimming layer is formed from an electrochromic (EC) material. EC materials are, for example, materials that can reversibly change between a colored non-transparent state and a colorless transparent state through electrochemical oxidation-reduction. Each transparent conductive layer is an electrode layer. By turning the voltage between the electrodes (transparent conductive layers) on and off, the dimming layer switches, for example, between a non-transparent state (light-blocking state) and a transparent state (non-light-blocking state). In a window glass to which such a dimming film is applied, the transmittance of light, such as visible light, through the window glass with the dimming film is switched by turning the voltage between the electrodes on and off (transmittance conversion control). Technology related to such a dimming film is described, for example, in Patent Document 1 below.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-101206 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] From the viewpoints of improving comfort and reducing cooling loads in buildings and vehicles, light-control films are required to have heat shielding properties against sunlight.

[0008] On the other hand, regarding the dimming film, the present inventors have obtained the following insights. The electrode (transparent conductive layer) contains free electrons as carriers that have significant reflectivity to heat rays in sunlight (electromagnetic waves such as near-infrared rays that transmit heat by radiation). In the dimming film, such electrodes are provided over the entire surface of the dimming layer. That is, the area occupied by the electrodes in the surface direction of the dimming film is large. In such a dimming film, by adjusting the number of carriers in the electrode, the heat insulation properties of the film against sunlight can be efficiently controlled. The present invention is based on such insights.

[0009] The present invention provides a light-adjusting film suitable for achieving good heat shielding properties against sunlight.

[0010] Solutions for solving problems

[0011] The present invention [1] includes a dimming film, which comprises a substrate film, a first electrode layer, a dimming layer, and a second electrode layer in the thickness direction, wherein the first electrode layer is an indium tin composite oxide layer with a tin oxide ratio of 11% by mass or more, and the first electrode layer has a 10×10 15 cm －2 The number of carriers above.

[0012] The present invention [2] includes the light-adjusting film described in [1] above, wherein the second electrode layer is an indium tin composite oxide layer having a tin oxide ratio of 11% by mass or more.

[0013] The present invention [3] includes the light-adjusting film described in [1] or [2] above, wherein the base film has a near-infrared absorbing layer and / or a near-infrared reflecting layer.

[0014] The present invention [4] includes the light-adjusting film according to any one of [1] to [3] above, wherein the average transmittance at a wavelength of 800 nm to 1300 nm is 50% or less.

[0015] Effects of the Invention

[0016] As described above, the light-adjusting film of the present invention comprises a base film, a first electrode layer, a light-adjusting layer and a second electrode layer in the order of thickness direction. The first electrode layer is an indium tin composite oxide layer with a tin oxide ratio of 11% by mass or more, and has a 10×10 15 cm －2 Such a dimming film is suitable for ensuring the number of free electrons (carriers) per unit area when viewed from above the first electrode layer. The greater the number of free electrons per unit area of ​​the first electrode layer, the higher the reflectivity of the first electrode layer to heat rays in sunlight. The higher the reflectivity of the first electrode layer to heat rays, the higher the shielding (heat insulation) of the dimming film with such a first electrode layer against heat rays. Therefore, the dimming film of the present invention is suitable for achieving good heat insulation against sunlight. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic cross-sectional view of one embodiment of the light-adjusting film of the present invention.

[0018] Figure 2 shows Figure 1 Part of the steps in one example of a method for producing a light-adjusting film is shown. Figure 2A Indicates the base film preparation process, Figure 2B 1 represents a transparent conductive layer forming step, Figure 2C represents the crystallization process, Figure 2D It shows the dimming layer forming process.

[0019] Figure 3 shows Figure 2D The bonding step follows the steps shown. DETAILED DESCRIPTION

[0020] The dimming film X, which is one embodiment of the present invention, comprises, in order along the thickness direction H, a base film 10 (first base film), an electrode layer 20 (first electrode layer), a dimming layer 30, an electrode layer 40 (second electrode layer), and a base film 50 (second base film). The base film 10 has a first surface 10a and a second surface 10b opposite the first surface 10a. The electrode layer 20 is disposed on the first surface 10a. The electrode layer 20 and the first surface 10a are in contact with each other. The dimming layer 30 is disposed on the electrode layer 20. The dimming layer 30 and the electrode layer 20 are in contact with each other. The electrode layer 40 is disposed on the dimming layer 30. The electrode layer 40 and the dimming layer 30 are in contact with each other. The base film 50 is disposed on the electrode layer 40. The base film 50 has a first surface 50a on the electrode layer 40 side and a second surface 50b opposite the first surface 50a. The electrode layer 40 and the first surface 50a are in contact with each other. Furthermore, the light-adjusting film X has a sheet shape that expands in a direction perpendicular to the thickness direction H (surface direction).

[0021] In the light-adjusting film X, the base film 10 and the electrode layer 20 form a base film Y1 with electrodes.

[0022] In this embodiment, the base film 10 includes a resin film 11 and a cured resin layer 12 in this order in the thickness direction H. The cured resin layer 12 is in contact with the resin film 11. The cured resin layer 12 forms the first surface 10a of the base film 10.

[0023] The resin film 11 is a base material that ensures the strength of the dimming film X. In addition, the resin film 11 is a flexible and transparent resin film. Examples of the material of the resin film 11 include polyester resins, polyolefin resins, acrylic resins, polycarbonate resins, polyethersulfone resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, cellulose resins, and polystyrene resins. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include polyethylene, polypropylene, and cycloolefin polymers. Examples of acrylic resins include polymethacrylate. From the viewpoint of transparency and strength, the material of the resin film 11 is preferably a polyester resin, and more preferably PET.

[0024] The surface of the resin film 11 on the side of the cured resin layer 12 may be subjected to a surface modification treatment. Examples of the surface modification treatment include corona treatment, plasma treatment, ozone treatment, primer treatment, glow treatment, and coupling agent treatment (the same applies to the surface modification treatment related to the resin film 51 described later).

[0025] To ensure the strength of the light-adjusting film X, the thickness of the resin film 11 is preferably 10 μm or greater, more preferably 20 μm or greater, and even more preferably 30 μm or greater. To ensure the handleability of the resin film 11 in a roll-to-roll process, the thickness of the resin film 11 is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. To achieve a balance between the strength and handleability of the light-adjusting film X, the thickness of the resin film 11 is preferably 10 to 300 μm, more preferably 20 to 200 μm, and even more preferably 30 to 150 μm.

[0026] To ensure the required transparency of the light-adjusting film X, the visible light transmittance of the resin film 11 is preferably 70% or higher, more preferably 80% or higher, and even more preferably 85% or higher. For example, the visible light transmittance of the resin film 11 is 100% or lower. The visible light transmittance is the transmittance within the wavelength range of 380 nm to 780 nm.

[0027] In this embodiment, the cured resin layer 12 is an optical adjustment layer (refractive index adjustment layer) for optimizing the optical characteristics of the light-adjusting film X. The cured resin layer 12 may have a transparent conductive layer forming step ( Figure 2B ) in the substrate film 10. In the present embodiment, the cured resin layer 12 is a cured product of a first resin composition of a curable type. The first resin composition contains a resin. Examples of the resin include: melamine resin, alkyd resin, organosilane condensate, polyester resin, acrylic urethane resin, acrylic resin (excluding acrylic urethane resin), urethane resin (excluding acrylic urethane resin), amide resin, silicone resin, and epoxy resin. These resins can be used alone or in combination of two or more. From the perspective of ensuring the adhesion of the electrode layer 20 to the substrate film 10, the resin in the first resin composition is preferably selected from at least one of the group consisting of melamine resin, alkyd resin, and organosilane condensate. In addition, the first resin composition can be a UV-curable resin composition or a thermosetting resin composition.

[0028] From the perspective of optimizing the light transmission characteristics of the dimming film X, the thickness of the cured resin layer 12 is preferably 5 nm or more, more preferably 10 nm or more, even more preferably 20 nm or more, and even more preferably 30 nm or more. From the perspective of thinning the dimming film X, the thickness of the cured resin layer 12 is preferably 1000 nm or less, more preferably 100 nm or less, even more preferably 50 nm or less, and even more preferably 40 nm or less. From the perspective of achieving both the light transmission characteristics of the dimming film X and thinning, the thickness of the cured resin layer 12 is preferably 5 to 1000 nm, more preferably 10 to 100 nm, even more preferably 20 to 50 nm, and even more preferably 30 to 40 nm.

[0029] The base film 10 may have another cured resin layer on the side opposite to the cured resin layer 12 with respect to the resin film 11. Examples of the other cured resin layer include a hard coat layer and an anti-blocking layer. Figure 1 In FIG. 1 , another cured resin layer in the base film 10 is indicated by a virtual line as a cured resin layer 13 .

[0030] The other cured resin layer is, for example, a cured product of a curable second resin composition. The second resin composition contains a resin. Examples of the resin 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. These resins can be used alone or in combination of two or more. The second resin composition can be a UV-curable resin composition or a thermosetting resin composition.

[0031] The second resin composition may contain particles. Examples of the particles include inorganic oxide particles and organic particles. Examples of materials for the inorganic oxide particles include silica, alumina, titania, zirconium oxide, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. Examples of materials for the organic particles include polymethyl methacrylate, polystyrene, polyurethane, acrylic acid / styrene copolymers, benzoguanamine, melamine, and polycarbonate. The particles are preferably inorganic oxide particles, and more preferably at least one selected from the group consisting of silica particles and zirconium oxide particles.

[0032] From the perspective of ensuring the functions of other cured resin layers, the thickness of the cured resin layer is preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more. From the perspective of reducing the thickness of the dimming film X, the thickness of the cured resin layer is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less. From the perspective of balancing the functions of the cured resin layer and reducing the thickness of the dimming film X, the thickness of the cured resin layer is preferably 0.5 to 10 μm, more preferably 1 to 5 μm, and even more preferably 2 to 3 μm.

[0033] From the perspective of ensuring the operability of the dimming film X, the thickness of the base film 10 is preferably 10 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, and even more preferably 60 μm or more. From the perspective of thinning the dimming film X, the thickness of the base film 10 is preferably 500 μm or less, more preferably 300 μm or less, even more preferably 200 μm or less, and even more preferably 150 μm or less. From the perspective of achieving both the operability and thinning of the dimming film X, the thickness of the base film 10 is preferably 10 to 500 μm, more preferably 30 to 300 μm, even more preferably 50 to 200 μm, and even more preferably 60 to 150 μm.

[0034] From the perspective of ensuring the transparency required for the light-adjusting film X, the visible light transmittance of the base film 10 is preferably 70% or higher, more preferably 80% or higher, and even more preferably 85% or higher. The visible light transmittance of the base film 10 is, for example, 100% or lower.

[0035] The substrate film 10 preferably includes a near-infrared absorbing layer and / or a near-infrared reflecting layer (each layer is not shown). The near-infrared absorbing layer is a layer that exhibits significant absorption of near-infrared rays (wavelength 700 nm to 2500 nm). The near-infrared reflecting layer is a layer that exhibits significant reflection of near-infrared rays (wavelength 700 nm to 2500 nm).

[0036] The near-infrared absorbing layer can be arranged between the resin film 11 and the cured resin layer 12, or it can be arranged on the opposite side of the resin film 11 from the cured resin layer 12. The resin film 11 can be a near-infrared absorbing layer, or it can have a multilayer structure including a near-infrared absorbing layer. The near-infrared absorbing layer includes, for example, a near-infrared absorber and a binder resin. Examples of near-infrared absorbers include inorganic near-infrared absorbers and organic near-infrared absorbers. Examples of inorganic near-infrared absorbers include CFM composite oxide particles and tungsten oxide particles. CFM composite oxide refers to a composite oxide of copper, iron, and manganese. Examples of the material of the binder resin include the materials described above for the resin film 11.

[0037] The near-infrared reflective layer can be arranged between the resin film 11 and the cured resin layer 12, or it can be arranged on the opposite side of the resin film 11 to the cured resin layer 12. The resin film 11 can be a near-infrared reflective layer, or it can have a multilayer structure including a near-infrared reflective layer. The near-infrared reflective layer has, for example, a multilayer structure including a plurality of resin thin layers having different optical properties, preferably a multilayer structure in which first and second resin thin layers having different optical properties are alternately arranged in the thickness direction H. As optical properties, for example, the in-plane average refractive index can be listed. The difference in the in-plane average refractive index between the first resin thin layer and the second resin thin layer is preferably 0.01 or more, more preferably 0.03 or more, and preferably 0.15 or less, more preferably 0.12 or less. The number of stacked resin thin layers forming the multilayer structure is, for example, 20 or more, and for example, 700 or less. As the material of the resin thin layer, for example, the materials described above for the resin film 11 can be listed.

[0038] The electrode layer 20 is a layer having both light transmittance and electrical conductivity. Such an electrode layer 20 is formed of a transparent conductive material. In other words, the electrode layer 20 is a transparent conductive layer.

[0039] The electrode layer 20 is formed of indium tin oxide (ITO), which is a transparent conductive material. That is, the electrode layer 20 is an indium tin oxide layer. ITO may contain a metal or semimetal other than In and Sn in an amount smaller than the content of In and Sn respectively.

[0040] From the perspective of appropriately suppressing the crystallization step ( Figure 2C ) in the transparent conductive layer and the viewpoint of ensuring the number of carriers of the electrode layer 20, the ratio of the tin oxide content in ITO to the total content of indium oxide (In2O3) and tin oxide (SnO2) (tin oxide ratio) is 11% by mass or more, preferably 12% by mass or more, and more preferably 12.5% ​​by mass or more. From the viewpoint of low resistance of the electrode layer 20, the tin oxide ratio is preferably 18% by mass or less, more preferably 16% by mass or less, and further preferably 14% by mass or less. From the viewpoint of taking into account both ensuring the above-mentioned number of carriers and the above-mentioned low resistance, the tin oxide ratio is preferably 11 to 18% by mass, more preferably 12 to 16% by mass, and further preferably 12.5 to 14% by mass.

[0041] The tin oxide ratio in ITO can be identified, for example, as follows. First, the presence ratio of indium atoms (In) and tin atoms (Sn) in ITO, the object of measurement, is determined by X-ray photoelectron spectroscopy. Based on the presence ratios of In and Sn in ITO, the ratio of the number of Sn atoms in ITO to the number of In atoms is determined. Thus, the tin oxide ratio in ITO is obtained. In addition, the tin oxide ratio in ITO can also be determined based on the tin oxide (SnO2) content ratio of the ITO target used in sputtering film formation.

[0042] The electrode layer 20 is preferably a crystalline film. The electrode layer 20 is preferably a crystalline film from the viewpoint of reducing the resistance of the electrode layer 20 and also from the viewpoint of achieving good infrared reflection characteristics in the electrode layer 20 and the light-adjusting film X.

[0043] Whether the electrode layer formed of a conductive oxide (electrode layer 20 and electrode layer 40 in the dimming film X) is a crystalline film can be determined, for example, by the following method. First, the electrode layer is immersed in 5% by mass hydrochloric acid at 20°C for 15 minutes. Next, the electrode layer is washed with water and dried. Next, the resistance between a pair of terminals separated by a distance of 15 mm (inter-terminal resistance) is measured on the exposed surface of the electrode layer. In this measurement, if the inter-terminal resistance is 10 kΩ or less, the electrode layer can be determined to be a crystalline film.

[0044] From the viewpoint of ensuring the heat insulation property in the electrode layer 20, the number of carriers (number of free electrons) in the top view (plane direction) of the electrode layer 20 is 10×10 15 cm －2 Above, preferably 12×10 15 cm －2 More than 14×10 15 cm －2 More preferably, 14.5×10 15 cm －2 The carrier number represents the number of carriers (free electrons) per unit area (1 square centimeter) of the electrode layer 20 when viewed from above. From the perspective of ensuring the visible light transmittance of the electrode layer 20, the carrier number (free electron number) of the electrode layer 20 when viewed from above is preferably 100×10 15 cm －2 Below, more preferably 60×10 15 cm －2 Below, more preferably 40×10 15 cm －2 Below, more preferably 20×10 15 cm －2From the perspective of ensuring both the heat insulation and visible light transmittance of the electrode layer 20, the number of carriers in the electrode layer 20 is preferably 10×10 15 ~100×10 15 cm －2 , more preferably 12×10 15 ~60×10 15 cm －2 , more preferably 14×10 15 ~40×10 15 cm －2 , and more preferably 14.5×10 15 ~20×10 15 cm －2 Methods for adjusting the number of carriers in the electrode layer 20 include, for example, adjusting the composition of the electrode layer 20, adjusting the thickness of the electrode layer 20, and the transparent conductive layer forming step described later ( Figure 2B ) in the film formation temperature. Adjustment of the composition of the electrode layer 20 includes adjustment of the composition of the target used in sputtering film formation during the transparent conductive layer formation step and adjustment of the ratio of oxygen introduction. The method for measuring the number of carriers in the electrode layer is described later in the Examples.

[0045] From the perspective of ensuring the number of carriers in the electrode layer 20, the thickness of the electrode layer 20 is preferably 50 nm or more, more preferably 80 nm or more, further preferably 100 nm or more, and further preferably 120 nm or more. From the perspective of reducing the resistance of the electrode layer 20, it is also preferred that the electrode layer 20 is thick. From the perspective of ensuring the bending resistance of the electrode layer 20 (suppressing the breakage of the electrode layer 20 when bent), the thickness of the electrode layer 20 is preferably 300 nm or less, more preferably 200 nm or less, further preferably 170 nm or less, and further preferably 140 nm or less. From the perspective of ensuring the number of carriers in the electrode layer 20, reducing the resistance, and bending resistance, the thickness of the electrode layer 20 is preferably 50 to 300 nm, more preferably 80 to 200 nm, further preferably 100 to 170 nm, and further preferably 120 to 140 nm.

[0046] From the viewpoint of reducing the resistance of the electrode layer 20, the resistivity of the electrode layer 20 is preferably 2.5×10 －4 Ω·cm or less, more preferably 2.3×10 －4 Ω·cm or less, more preferably 2.1×10 －4 Ω·cm or less, more preferably 2.0×10 －4 Ω·cm or less. In addition, the resistivity of the electrode layer 20 is preferably 0.1×10 －4 Ω·cm or more, more preferably 0.5×10 －4Ω·cm or more, more preferably 1.0×10 －4 Ω·cm or more. The method for measuring the resistivity of the electrode layer is as described later in the examples. As a method for adjusting the resistivity, for example, the following method can be cited: Figure 2B ) in the sputtering film formation process. Examples of such conditions include the temperature of the substrate on which the film is formed (the base film 10 in this embodiment), the amount of oxygen introduced into the film formation chamber, the gas pressure in the film formation chamber, and the horizontal magnetic field strength on the target.

[0047] In the case where the electrode layer 20 is an amorphous film crystallized by heating, the resistivity of the electrode layer 20 is preferably 4.5×10 －4 Ω·cm or more, preferably 4.8×10 －4 Ω·cm or more, more preferably 5.0×10 －4 Ω·cm or more, more preferably 5.2×10 －4 Ω·cm or more, preferably 15×10 －4 Ω·cm or less, more preferably 13×10 －4 Ω·cm or less, more preferably 11×10 －4 Ω·cm or less, more preferably 9.0×10 －4 Ω·cm or less, and more preferably 8.0×10 －4 Ω·cm or less.

[0048] From the perspective of ensuring the required transparency of the light-adjusting film X, the visible light transmittance of the electrode layer 20 is, for example, 50% or more, preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more. Furthermore, the visible light transmittance of the electrode layer 20 is, for example, 100% or less.

[0049] From the viewpoint of reducing the resistance (low resistivity) of the electrode layer 20, the content of the rare gas atoms in the electrode layer 20 is preferably 0.3 atomic % or less, more preferably 0.2 atomic % or less, further preferably 0.1 atomic % or less, and for example, 0.0001 atomic % or more. Examples of the rare gas atoms include argon (Ar), krypton (Kr), and xenon (Xe). The rare gas atoms are derived, for example, from the transparent conductive layer formation step ( Figure 2B) (when sputtering gas is mixed). Examples of methods for identifying the content ratio of rare gas atoms in the electrode layer 20 include fluorescent X-ray analysis and Rutherford backscattering spectroscopy (RBS) (the same applies to the method for identifying the content ratio of rare gas atoms in the electrode layer 40 described later).

[0050] The dimming layer 30 is formed, for example, from a material that can reversibly change between a colored, non-transparent state (light-blocking state) and a transparent state (non-light-blocking state) through the action of an electric current or an electric field. Examples of the dimming layer 30 include an electrochromic (EC) dimming layer, a dimming layer comprising polymer dispersed liquid crystal (PDLC), a dimming layer comprising polymer network liquid crystal (PNLC), and an SPD (suspended particle device) dimming layer.

[0051] The EC dimming layer is formed from an EC material. EC materials are materials that can reversibly change between a colored, non-transparent state (light-blocking state) and a transparent state (non-light-blocking state) through electrochemical oxidation-reduction. Examples of EC materials include inorganic EC materials and organic EC materials. Examples of inorganic EC materials include tungsten oxide, vanadium oxide, molybdenum oxide, iridium oxide, rhodium oxide, and indium nitride. Examples of organic EC materials include polyaniline, viologen, and tungsten oxide clusters.

[0052] Polymer-dispersed liquid crystals have a structure in which the liquid crystals undergo phase separation within the polymer. Polymer-network liquid crystals have a structure in which the liquid crystals are dispersed within the polymer network, with the liquid crystals in the polymer network forming a continuous phase. Examples of liquid crystal compounds include nematic liquid crystal compounds, smectic liquid crystal compounds, and cholesteric liquid crystal compounds. Examples of nematic liquid crystal compounds include biphenyl compounds, phenyl benzoate compounds, cyclohexylbenzene compounds, azoxybenzene compounds, azobenzene compounds, azomethine compounds, terphenyl compounds, biphenyl benzoate compounds, cyclohexylbiphenyl compounds, phenylpyridine compounds, cyclohexylpyrimidine compounds, and cholesterol compounds.

[0053] To ensure a large difference in visible light transmittance between the opaque and transparent states of the light-adjusting film X, the thickness of the light-adjusting layer 30 is preferably 1 μm or greater, more preferably 5 μm or greater, and even more preferably 10 μm or greater. To achieve both thinness and high transmittance in the transparent state of the light-adjusting film X, the thickness of the light-adjusting layer 30 is preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less. To achieve a balance between the aforementioned visible light transmittance difference and the aforementioned thinness and high transmittance of the light-adjusting film X, the thickness of the light-adjusting layer 30 is preferably 1 to 200 μm, more preferably 5 to 100 μm, and even more preferably 10 to 80 μm.

[0054] In the light-adjusting film X, the base film 50 and the electrode layer 40 form a base film Y2 with an electrode.

[0055] In this embodiment, the base film 50 includes a resin film 51 and a cured resin layer 52 in this order in the thickness direction H. The cured resin layer 52 is in contact with the resin film 51. The cured resin layer 52 forms the first surface 50a of the base film 50.

[0056] The resin film 51 is a base material that ensures the strength of the light-adjusting film X. Furthermore, the resin film 51 is a flexible, transparent resin film. Examples of materials for the resin film 51 include the materials described above for the resin film 11. The surface of the resin film 51 facing the cured resin layer 52 may be surface-modified. The preferred thickness and visible light transmittance of the resin film 51 are the same as those described above for the resin film 11.

[0057] In this embodiment, the cured resin layer 52 is an optical adjustment layer (refractive index adjustment layer) for optimizing the optical properties of the light-adjusting film X. The cured resin layer 52 may have the function of blocking moisture and organic gases generated by the resin film 51 during the transparent conductive layer formation process. In this embodiment, the cured resin layer 52 is a cured product of a curable third resin composition. The third resin composition contains a resin. As the resin of the third resin composition, for example, the resins described above with respect to the first resin composition can be cited. In addition, the third resin composition may be a UV-curable resin composition or a thermosetting resin composition.

[0058] From the perspective of optimizing the light transmission characteristics of the dimming film X, the thickness of the cured resin layer 52 is preferably 5 nm or greater, more preferably 10 nm or greater, even more preferably 20 nm or greater, and even more preferably 30 nm or greater. From the perspective of reducing the thickness of the dimming film X, the thickness of the cured resin layer 52 is preferably 1000 nm or less, more preferably 100 nm or less, even more preferably 50 nm or less, and even more preferably 40 nm or less. From the perspective of achieving both the light transmission characteristics of the dimming film X and reducing the thickness, the thickness of the cured resin layer 52 is preferably 5 to 1000 nm, more preferably 10 to 100 nm, even more preferably 20 to 50 nm, and even more preferably 30 to 40 nm.

[0059] The base film 50 is the same as the base film described above with respect to the base film 10, and may have other cured resin layers (such as a hard coating layer and an anti-blocking layer) on the side opposite to the cured resin layer 52 with respect to the resin film 51. Figure 1 In FIG. 5 , another cured resin layer in the base film 50 is indicated by a virtual line as a cured resin layer 53 .

[0060] From the perspective of ensuring the transparency required for the light-adjusting film X, the visible light transmittance of the base film 50 is preferably 70% or higher, more preferably 80% or higher, and even more preferably 85% or higher. The visible light transmittance of the base film 50 is, for example, 100% or lower.

[0061] The base film 50 preferably includes a near-infrared ray absorption layer and / or a near-infrared ray reflection layer (each layer is not shown in the figure).

[0062] In the base film 50, the near-infrared absorbing layer can be positioned between the resin film 51 and the cured resin layer 52, or on the side of the resin film 51 opposite the cured resin layer 52. The resin film 51 can be a near-infrared absorbing layer, or it can have a multilayer structure including a near-infrared absorbing layer. The near-infrared absorbing layer, for example, includes a near-infrared absorber and a binder resin. Examples of the near-infrared absorber include those described above with respect to the base film 10. Examples of the binder resin include those described above with respect to the resin film 11.

[0063] In the base film 50, the near-infrared reflective layer may be disposed between the resin film 51 and the cured resin layer 52, or may be disposed on the side of the resin film 51 opposite to the cured resin layer 52. The resin film 51 may be a near-infrared reflective layer or may have a multilayer structure including a near-infrared reflective layer. Examples of the near-infrared reflective layer include the near-infrared reflective layer described above with respect to the base film 10.

[0064] The electrode layer 40 is a layer having both light transmittance and electrical conductivity. The electrode layer 40 is formed of a transparent conductive material. That is, the electrode layer 40 is a transparent conductive layer. Examples of transparent conductive materials include conductive oxides containing indium and conductive oxides containing antimony. Examples of conductive oxides containing indium include indium tin composite oxide (ITO), indium zinc composite oxide (IZO), indium gallium composite oxide (IGO), and indium gallium zinc composite oxide (IGZO). Examples of conductive oxides containing antimony include antimony tin composite oxide (ATO). From the perspective of achieving high transparency and good electrical conductivity, the transparent conductive material is preferably a conductive oxide containing indium, more preferably ITO. That is, the electrode layer 40 is preferably a conductive oxide layer containing indium, more preferably an ITO layer. The ITO may contain a metal or semimetal other than In and Sn in an amount less than the content of In and Sn respectively.

[0065] When the electrode layer 40 is formed of ITO, from the perspective of appropriately suppressing the growth of grains in the transparent conductive layer in the crystallization process described later and ensuring the number of carriers in the electrode layer 40, the ratio of the tin oxide content in ITO to the total content of indium oxide (In2O3) and tin oxide (SnO2) (tin oxide ratio) is preferably 11% by mass or more, more preferably 12% by mass or more, and further preferably 12.5% ​​by mass or more. The tin oxide ratio in the electrode layer 40 may also be less than 11% by mass. From the perspective of reducing the resistance of the electrode layer 40, the tin oxide ratio in the electrode layer 40 is preferably 18% by mass or less, more preferably 16% by mass or less, and further preferably 14% by mass or less. From the perspective of ensuring both the above-mentioned number of carriers and the above-mentioned low resistance, the tin oxide ratio in the electrode layer 40 is preferably 11 to 18% by mass, more preferably 12 to 16% by mass, and further preferably 12.5 to 14% by mass.

[0066] The electrode layer 40 is preferably a crystalline film. The electrode layer 40 is preferably a crystalline film from the viewpoint of reducing the resistance of the electrode layer 40 and also from the viewpoint of achieving good infrared reflection characteristics in the electrode layer 40 and the light-adjusting film X.

[0067] From the viewpoint of ensuring the heat insulation property in the electrode layer 40, the number of carriers (number of free electrons) in the top view (plane direction) of the electrode layer 40 is preferably 10×10 15 cm －2 More than 12×10 15 cm －2 More preferably, 14×10 15 cm －2 More preferably, 14.5×10 15 cm －2The number of carriers in the electrode layer 40 when viewed from above may be less than 10×10 15 cm －2 From the perspective of ensuring the visible light transmittance of the electrode layer 40, the number of carriers (number of free electrons) in the electrode layer 40 when viewed from above is preferably 100×10 15 cm －2 Below, more preferably 60×10 15 cm －2 Below, more preferably 40×10 15 cm －2 Below, more preferably 20×10 15 cm －2 From the perspective of ensuring both the heat insulation and visible light transmittance of the electrode layer 40, the number of carriers in the electrode layer 40 is preferably 10×10 15 ~100×10 15 cm －2 , more preferably 12×10 15 ~60×10 15 cm －2 , more preferably 14×10 15 ~40×10 15 cm －2 , and more preferably 14.5×10 15 ~20×10 15 cm －2 The method for adjusting the number of carriers in the electrode layer 40 is the same as the method described above as the method for adjusting the number of carriers in the electrode layer 20 .

[0068] From the perspective of ensuring the number of carriers in the electrode layer 40, the thickness of the electrode layer 40 is preferably 50 nm or more, more preferably 80 nm or more, further preferably 100 nm or more, and further preferably 120 nm or more. From the perspective of reducing the resistance of the electrode layer 40, it is also preferred that the electrode layer 40 is thick. From the perspective of ensuring the bending resistance of the electrode layer 40 (suppressing the breakage of the electrode layer 40 during bending), the thickness of the electrode layer 40 is preferably 300 nm or less, more preferably 200 nm or less, further preferably 170 nm or less, and further preferably 140 nm or less. From the perspective of ensuring the number of carriers in the electrode layer 40, reducing the resistance, and bending resistance, the thickness of the electrode layer 40 is preferably 50 to 300 nm, more preferably 80 to 200 nm, further preferably 100 to 170 nm, and further preferably 120 to 140 nm.

[0069] From the perspective of ensuring the required transparency of the light-adjusting film X, the visible light transmittance of the electrode layer 40 is, for example, 50% or more, preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more. Furthermore, the visible light transmittance of the electrode layer 40 is, for example, 100% or less.

[0070] From the viewpoint of reducing the resistance (low resistivity) of the electrode layer 40, the content of the rare gas atoms in the electrode layer 40 is preferably 0.3 atomic % or less, more preferably 0.2 atomic % or less, further preferably 0.1 atomic % or less, and for example, 0.0001 atomic % or more. Examples of the rare gas atoms include argon (Ar), krypton (Kr), and xenon (Xe). The rare gas atoms are derived, for example, from the transparent conductive layer formation step ( Figure 2B ) is the sputtering gas used (in the case where sputtering gas is mixed).

[0071] To ensure the transparency of the light-adjusting film X, the visible light transmittance (in a transparent state) of the light-adjusting film X is preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more. The visible light transmittance of the base film 10 is, for example, 100% or less.

[0072] From the perspective of ensuring good heat shielding against sunlight in the dimming film X, the average transmittance of the dimming film X at a wavelength of 800 nm to 1300 nm is preferably 50% or less, more preferably 40% or less, and even more preferably 30% or less. The average transmittance of the dimming film X is, for example, 0% or greater, and preferably 10% or greater. The dimming film X preferably has this average transmittance (wavelength 800 nm to 1300 nm) in either the opaque or transparent state, and more preferably has this average transmittance (wavelength 800 nm to 1300 nm) in both the opaque and transparent states.

[0073] The light-adjusting film X is produced, for example, as follows.

[0074] First, if Figure 2AAs shown, a base film 10 is prepared. The base film 10 can be produced by forming a cured resin layer 12 on a resin film 11. The cured resin layer 12 can be formed by applying the above-mentioned first resin composition on the resin film 11 to form a coating film and then curing the coating film. In the case where the first resin composition contains a thermosetting resin, the coating film is cured by heating. In the case where the first resin composition contains an ultraviolet curing resin, the coating film is cured by ultraviolet irradiation. The exposed surface of the cured resin layer 12 formed on the resin film 11 is subjected to surface modification treatment as needed. In the case of performing plasma treatment as the surface modification treatment, argon gas is used as an inert gas, for example. In addition, the discharge power in the plasma treatment is, for example, 10 W or more, and in addition, for example, 5000 W or less. In addition, the above-mentioned other cured resin layer 13 ( Figure 1 ).

[0075] Then, if Figure 2B As shown, an amorphous transparent conductive layer 20' is formed on the base film 10 (transparent conductive layer forming step). Specifically, a transparent conductive material is formed on the cured resin layer 12 in the base film 10 by sputtering to form the transparent conductive layer 20'.

[0076] In the sputtering method, it is preferable to use a sputtering film-forming apparatus capable of performing a roll-to-roll film-forming process. In the production of the light-adjusting film X, when a roll-to-roll sputtering film-forming apparatus is used, a long substrate film 10 is fed from a delivery roll to a take-up roll provided by the apparatus, and a material is formed on the substrate film 10 to form the transparent conductive layer 20'. Furthermore, the sputtering method can be used with a single film-forming chamber or with multiple film-forming chambers arranged sequentially along the path of the substrate film 10.

[0077] In the sputtering method, specifically, a sputtering gas (inert gas) is introduced into a 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 in the film forming chamber. This generates a glow discharge, ionizes gas atoms, and causes the gas ions to collide with the target surface at high speed, ejecting the target material from the target surface, and depositing the ejected target material on the substrate film 10. As a target material, for example, a sintered body of the conductive oxide described above for the electrode layer 20 is used. Examples of the sputtering gas include rare gas atoms. Examples of rare gas atoms include argon (Ar), krypton (Kr), and xenon (Xe).

[0078] The sputtering method is preferably a reactive sputtering method. In the reactive sputtering method, for example, a sputtering gas (inert gas) and oxygen as a reactive gas are introduced into the film forming chamber. From the viewpoint of ensuring the number of carriers of the electrode layer 20, the ratio of the amount of oxygen introduced into the film forming chamber in the reactive sputtering method to the total amount of sputtering gas and oxygen introduced is preferably 1.5 flow% or more, more preferably 2.0 flow% or more, and further preferably 2.2 flow% or more. From the viewpoint of ensuring good crystallinity of the electrode layer 20, the ratio of the amount of oxygen introduced is preferably 3.2 flow% or less, more preferably 3.0 flow% or less, and further preferably 2.8 flow% or less. From the viewpoint of taking into account both the number of carriers and the crystallinity of the electrode layer 20, the ratio of the amount of oxygen introduced is preferably 1.5-3.2 flow%, more preferably 2.0-3.0 flow%, and further preferably 2.2-2.8 flow%.

[0079] The gas pressure in the film forming chamber in film formation by sputtering (sputtering film formation) is, for example, 0.02 Pa or more, preferably 0.1 Pa or more, more preferably 0.2 Pa or more, and is, for example, 1 Pa or less, preferably 0.7 Pa or less, more preferably 0.5 Pa or less.

[0080] From the perspective of appropriately forming an amorphous transparent conductive layer capable of undergoing crystal growth in the subsequent crystallization step, the film formation temperature during sputtering (the temperature of the substrate film 10 during sputtering) is preferably 50°C or lower, more preferably 30°C or lower, even more preferably 10°C or lower, even more preferably 0°C or lower, and even more preferably -5°C or lower. The film formation temperature is, for example, -30°C or higher or -20°C or higher.

[0081] Examples of power sources for applying voltage to the target include DC power supplies, AC power supplies, MF power supplies, and RF power supplies. A DC power supply and an RF power supply may also be used in combination. The absolute value of the discharge voltage during sputtering is, for example, 50 V or greater, and, for example, 500 V or less. The horizontal magnetic field intensity on the target is, for example, 10 mT or greater, and, for example, 100 mT or less.

[0082] Then, if Figure 2C As shown, the transparent conductive layer 20' ( Figure 2B ) is crystallized to form the electrode layer 20 (crystalline transparent conductive layer) (crystallization step).

[0083] Thus, a substrate film Y1 with an electrode is produced. As a heating unit, for example, an infrared heater and an oven (heat medium heating oven, hot air heating oven) can be listed. From the viewpoint of ensuring a high crystallization rate, the heating temperature is preferably 100°C or higher, more preferably 120°C or higher. From the viewpoint of suppressing the influence of heating on the substrate film 10, the heating temperature is preferably 200°C or lower, more preferably 170°C or lower, and further preferably 150°C or lower. The heating time is, for example, less than 600 minutes, preferably less than 120 minutes, more preferably 90 minutes or less, further preferably 60 minutes or less, and, for example, more than 1 minute, preferably more than 5 minutes.

[0084] Then, if Figure 2D As shown, the dimming layer 30 is formed on the electrode layer 20. When an inorganic EC material is used as the material for forming the dimming layer 30, the inorganic EC material is formed into a film on the electrode layer 20 by, for example, dry coating. Sputtering is preferred as the dry coating method. When an organic EC material is used as the material for forming the dimming layer 30, the organic EC material is formed into a film on the electrode layer 20 by, for example, wet coating.

[0085] On the other hand, a base film Y2 with an electrode (base film 50, electrode layer 40) is produced. Specifically, the method for producing the base film Y1 with an electrode ( Figures 2A to 2C )same.

[0086] Then, if Figure 3A and Figure 3B As shown, the base film Y1 with electrodes and the base film Y2 with electrodes are integrated with the light-adjusting layer 30. Specifically, the base films Y1 and Y2 with electrodes and the light-adjusting layer 30 are integrated so that the light-adjusting layer 30 is sandwiched between the base films Y1 and Y2 with electrodes.

[0087] As described above, a dimming film X can be manufactured. In the dimming film X, the dimming layer 30 switches between a non-transparent state (light-blocking state) and a transparent state (non-light-blocking state) by switching the voltage between the electrode layers 20 and 40. Such a dimming film X is, for example, a dimming film installed on window glass in buildings and vehicles. In window glass coated with the dimming film X, the transmittance of light, such as visible light, through the window glass coated with the dimming film X is switched by switching the voltage between the electrode layers 20 and 40.

[0088] As for the light-adjusting film X, as described above, the electrode layer 20 is an indium tin composite oxide layer with a tin oxide ratio of 11% by mass or more, and has a 10×10 15 cm －2The number of carriers is greater than or equal to 1. Such a dimming film X is suitable for ensuring the number of free electrons (carriers) per unit area when viewed from above the electrode layer 20. The greater the number of free electrons in the electrode layer 20, the higher the reflectivity of the electrode layer 20 to heat rays in sunlight, and therefore, the higher the heat insulation of the dimming film X. Therefore, the dimming film X is suitable for achieving good heat insulation against sunlight. Such a dimming film X is suitable as a dimming film for outdoor use. Examples of dimming films for outdoor use include dimming films for sunroofs of private cars and the like, and dimming films for windows of buildings such as houses and buildings.

[0089] As for the light-adjusting film X, as described above, it is preferable that the electrode layer 40 is an indium tin composite oxide layer with a tin oxide ratio of 11% by mass or more, and has a 10×10 15 cm －2 The light-adjusting film X includes the electrode layer 40 in addition to the electrode layer 20 , which contributes to achieving good heat shielding properties against sunlight in the light-adjusting film.

[0090] Example

[0091] The present invention will be described in detail below with reference to the following examples. However, the present invention is not limited to the examples. In addition, the specific numerical values ​​of the following amounts (contents), physical properties, parameters, etc. may be replaced by the upper limits (defined as "below" or "less than") or lower limits (defined as "above" or "greater than") of the amounts (contents), physical properties, parameters, etc. corresponding to these amounts (contents), physical properties, parameters, etc. described in the above-mentioned "Detailed Description of the Invention".

[0092] [Example 1]

[0093] First, a roll of polyethylene terephthalate (PET) film (thickness 100 μm, manufactured by Mitsubishi Chemical Corporation) as a long resin film is prepared. Then, a thermosetting resin composition C1 is applied to one side (first side) of the PET film to form a coating film. The resin composition C1 contains 100 parts by mass of melamine resin, 100 parts by mass of alkyd resin and 50 parts by mass of organosilane condensate. Then, the coating film on the PET film is heated to thermally cure it. The heating temperature is set to 185°C. The heating time is set to 1 minute. Thus, a first cured resin layer with a thickness of 35 nm is formed as an optical adjustment layer. Then, an ultraviolet curing resin composition C2 is applied to the other side (second side) of the PET film to form a coating film. Then, the coating film is cured by ultraviolet irradiation. Thus, a second cured resin layer with a thickness of 2 μm is formed as a hard coat (HC) layer. As described above, a base film (first cured resin layer / base film / second cured resin layer) is produced.

[0094] Next, a 125nm thick amorphous transparent conductive layer was formed on the first cured resin layer in the substrate film using a reactive sputtering method (transparent conductive layer formation step). A roll-to-roll sputtering film-forming apparatus (DC magnetron sputtering film-forming apparatus) was used for this step. The apparatus includes a film-forming chamber capable of carrying out the film-forming process while feeding the working film in a roll-to-roll manner. The sputtering film-forming conditions in this step are as follows.

[0095] During sputtering film formation, the sputtering film formation device is evacuated until the ultimate vacuum degree in the film formation chamber reaches 0.5×10 －4 Pa, argon (Ar) as a sputtering gas (inert gas) and oxygen as a reactive gas are introduced into the film forming chamber, and the gas pressure in the film forming chamber is set to 0.3 Pa. The ratio of the amount of oxygen introduced into the film forming chamber to the total amount of argon and oxygen introduced is set to 2.4 flow%. In addition, as a target (first target), a sintered body of indium oxide and tin oxide (ITO with a tin oxide ratio of 12.5% ​​by mass) is used. As a power supply for applying voltage to the target, a DC power supply is used. The horizontal magnetic field intensity on the target is set to 90mT. The film forming temperature (the temperature of the base film to be laminated with the transparent conductive layer) is set to -8°C. The resistivity of the formed transparent conductive layer (amorphous) is 6.5×10 －4 Ω·cm.

[0096] Next, the amorphous transparent conductive layer was crystallized by heating in a hot air oven (crystallization step). The heating temperature was set to 150°C and the heating time was set to 2 hours. Thus, a crystalline transparent conductive layer with a thickness of 125 nm was formed as an electrode layer. The resistivity of the formed transparent conductive layer was 1.7×10 －4 Ω·cm.

[0097] As described above, a roll of a film with an electrode layer is produced. The film with an electrode layer includes a base film (second cured resin layer / resin film / first cured resin layer) and an electrode layer on the base film.

[0098] Next, two sheets of electrode-layered film were cut from the roll. Next, an adhesive (LUCIACS CS9861UA, manufactured by Nitto Denko Corporation) was applied to the electrode layer of one of the electrode-layered films (the first electrode-layered film) to form a 25 μm thick adhesive layer, serving as the pseudo-light-modulating layer. Next, the electrode layer side of the other electrode-layered film (the second electrode-layered film) was attached to the adhesive layer. In other words, the two electrode-layered films were bonded together via the adhesive layer.

[0099] As described above, a laminated film of Example 1 was produced. This laminated film is an analog dimming film having a laminated structure similar to a dimming film (this film has an analog morphology and does not have a dimming function). Specifically, the laminated film of Example 1 comprises, in the thickness direction, a first base film, a first electrode layer with a thickness of 125 nm, an analog dimming layer, a second electrode layer with a thickness of 125 nm, and a second base film.

[0100] [Comparative Example 1]

[0101] A laminated film of Comparative Example 1 was produced in the same manner as the laminated film of Example 1 except for the following matters.

[0102] In the reactive sputtering process for forming the transparent conductive layer, a second target was used instead of the first target, and the ratio of the oxygen introduced into the film forming chamber to the total amount of argon and oxygen introduced was set to 3.4% by mass. The second target was a sintered body of indium oxide and tin oxide, and was ITO with a tin oxide ratio of 10.0% by mass. In addition, the crystallization process was not performed. The resistivity of the formed transparent conductive layer was 4.8×10 －4 Ω·cm.

[0103] [Comparative Example 2]

[0104] A laminated film of Comparative Example 2 was produced in the same manner as the laminated film of Example 1 except for the following matters.

[0105] In the transparent conductive layer formation process, a first layer of an amorphous transparent conductive layer (thickness 11 nm) is formed on the first cured resin layer in the substrate film by reactive sputtering, and then a second layer of an amorphous transparent conductive layer (thickness 11 nm) is formed on the first layer. In this process, a roll-to-roll sputtering film forming device (DC magnetron sputtering film forming device) is used. The device is equipped with a first film forming chamber and a second film forming chamber that can advance the working film in a roll-to-roll manner and perform the film forming process. The resistivity of the transparent conductive layer formed by heating in the crystallization process (at 150°C for 2 hours) is 3.1×10 －4 Ω·cm.

[0106] The sputtering film forming conditions in the first film forming chamber were the same as those in Example 1, except for the following: The film forming temperature was set to 80° C. instead of −8° C. As the target, the second target (ITO with a tin oxide ratio of 10% by mass) was used instead of the first target.

[0107] The sputtering film formation conditions in the second film formation chamber were the same as those described above for the sputtering film formation in Example 1, with the following exceptions. The film formation temperature was set to 80°C instead of -8°C. A third target was used instead of the first target. The third target was a sintered compact of indium oxide and tin oxide, and was ITO with a tin oxide ratio of 3% by mass.

[0108] The laminated film of Comparative Example 2 includes, in order of thickness, a first base film, a first electrode layer with a thickness of 22 nm, an analog light-adjusting layer, a second electrode layer with a thickness of 22 nm, and a second base film.

[0109] <Thickness of electrode layer>

[0110] The thickness of the electrode layer of the film with an electrode layer obtained during the production process of each laminated film in the examples and comparative examples was measured by observation using a field emission transmission electron microscope (FE-TEM observation). Specifically, first, a sample (first sample) for cross-sectional observation of each electrode layer in the examples and comparative examples was produced by FIB (Focused Ion Beam) processing (FIB microsampling method). In the FIB microsampling method, a FIB device (product name "FB2200", manufactured by HITACHI) was used, and the acceleration voltage was set to 10 kV. Next, the cross-section of the electrode layer in the first sample was observed using FE-TEM, and the thickness of the electrode layer was measured in the observed image. In the observation, a FE-TEM device (product name "JEM-2800", manufactured by JEOL) was used, and the acceleration voltage was set to 200 kV.

[0111] The thickness of the first layer of the electrode layer (transparent conductive layer) in Comparative Example 2 was measured by FE-TEM observation of a cross-sectional sample prepared from an intermediate product before forming the second layer on the first layer. The thickness of the second layer of the electrode layer (transparent conductive layer) in Comparative Example 2 was determined by subtracting the thickness of the first layer from the total thickness of the electrode layer in Comparative Example 2.

[0112] Resistivity

[0113] The resistivity of the electrode layer (transparent conductive layer) of the electrode-layer-bearing film obtained during the production of each laminated film in the Examples and Comparative Examples was determined as follows. First, the surface resistance of the electrode layer was measured using the four-probe method in accordance with JIS K7194 (1994). Next, the resistivity (Ω·cm) of the electrode layer (transparent conductive layer) was determined by multiplying the surface resistance value by the thickness of the electrode layer.

[0114] Number of carriers

[0115] The number of carriers (cm2) in the electrode layer of the film with an electrode layer obtained in the process of producing each laminated film of Examples and Comparative Examples was measured using a Hall effect measuring device (product name "HL5500PC", manufactured by BIO-RAD). －2 The measurement results are shown in Table 1.

[0116] Transmittance, Reflectance

[0117] For each laminated film of the embodiment and the comparative example, the direct transmittance of sunlight (Te) and the direct reflectance of sunlight (Re) in the wavelength range of 300nm to 2500nm were measured using a spectrophotometer U-4100 (manufactured by HITACHI Corporation). In this measurement, the measurement interval was set to 5nm. The measurement results are shown in Table 1. Sunlight refers to radiation in the wavelength range of 300nm to 2500nm. The direct transmittance of sunlight (Te) is calculated based on the product and sum of the provisions of the spectral transmittance and the spectral solar illuminance included in the formula, and is calculated using a spectrophotometer. The direct reflectance of sunlight (Re) is calculated based on the product and sum of the provisions of the spectral reflectance and the spectral solar illuminance included in the formula, and is calculated using a spectrophotometer.

[0118] Total Solar Transmittance

[0119] The total solar transmittance of each laminated film of the Examples and Comparative Examples was determined. Specifically, the total solar transmittance of the laminated film was determined using the following equations (1) to (3) based on ISO 13837:2021. In equation (1), Tts represents the total solar transmittance, which is an indicator of thermal insulation properties.

[0120] Tts=Te+Qi (1)

[0121] Qi=Ae×{hi / (hi+he)} (2)

[0122] Ae=100-Te-Re (3)

[0123] For each laminated film of the embodiment and comparative example, formulas (1) to (3) are as follows. Tts represents the total ratio (%) of the energy passing through the sample when the total energy of the light irradiating the sample (irradiation light) is set to 100%. Te represents the energy of the light (transmitted light) that transmits the sample in the irradiation light. As Te, the direct transmittance of sunlight obtained in the above measurement is used. Qi represents the secondary heat flow rate through the sample, which is calculated by formula (2). The smaller the value, the less likely the sample is to transfer heat and the higher the thermal insulation. In formula (2), Ae represents the energy absorbed by the sample in the energy of the irradiation light on the sample in the ratio, which is calculated by formula (3). hi is a parameter that represents the ease with which heat in the sample is transferred in the same direction as the light passing direction. As hi, 8W / (m 2 ·K). he is a parameter that indicates how easily heat in a sample is transferred in the direction opposite to the direction in which light passes. As he, 21W / (m 2 In formula (3), Re represents the energy of light reflected by the sample (reflected light) in proportion to the light irradiating the sample. The direct sunlight reflectance obtained in the above measurement is used as Re.

[0124] [Table 1]

[0125]

[0126] 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.

[0127] Industrial applicability

[0128] The light-adjusting film of the present invention is suitable as a light-adjusting film facing outdoors, such as a light-adjusting film for sunroofs of cars and the like, and a light-adjusting film for windows of buildings and the like.

[0129] Description of Reference Numerals

[0130] X: dimming film; H: thickness direction; Y1, Y2: substrate film with electrodes; 10, 50: substrate film; 11, 51: resin film; 12, 52: cured resin layer; 20: electrode layer (first electrode layer); 30: dimming layer; 40: electrode layer (second electrode layer).

Claims

1. A dimming film comprising a base film, a first electrode layer, a dimming layer, and a second electrode layer in this order in the thickness direction. The first electrode layer is an indium tin composite oxide layer having a tin oxide ratio of 11% by mass or more. The first electrode layer has a 10×10 15 cm －2 The number of carriers above.

2. The dimming film according to claim 1, wherein: The second electrode layer is an indium tin composite oxide layer having a tin oxide ratio of 11% by mass or more.

3. The dimming film according to claim 1, wherein: The base film has a near-infrared ray absorption layer and / or a near-infrared ray reflection layer.

4. The light-adjusting film according to any one of claims 1 to 3, wherein: The average transmittance at a wavelength of 800 nm to 1300 nm is 50% or less.

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