Electrochromic element and spectacle lens

Abstract

The purpose of the present invention is to provide an electrochromic element in which reflection at a boundary between an electrode layer and a substrate is suppressed, and wear comfort and other characteristics are not compromised, and to provide a spectacle lens that uses the electrochromic element. This electrochromic element (10) is characterized by having substrates (1, 2) and an electrochromic film (3) which is positioned overlapping the substrates, the electrochromic film having electrode layers (4, 5) and an electrochromic layer (6), and the luminous reflectance of interfaces (11, 12) with the substrate sides of the electrode layers being 1.0% or less. Preferably, the electrode layers are transparent electrode layers comprising ITO, and the luminous reflectance of the interface of the ITO with the substrate side is 1.0% or less.

Description

Technical Field

[0001] The present invention relates to an electrochromic element capable of reversibly controlling electrochromism by electricity, and a spectacle lens using the same.

Background Art

[0002] An electrochromic element that utilizes the electrochromism phenomenon in which a reversible oxidation-reduction reaction occurs by applying a voltage to reversibly change the color is used, for example, as a spectacle lens. The electrochromic element has a configuration in which an electrochromic film having an electrode layer and an electrochromic layer is disposed on the surface of a substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described in Patent Documents 1 and 2, a transparent electrode layer made of ITO or the like is generally used for the electrode layer. However, the refractive index of the transparent electrode layer is higher than that of other material layers in the electrochromic film, and strong reflection occurs at the interface between the electrode layer and the substrate. For this reason, for example, when an electrochromic element with strong reflection is used as a spectacle lens, it has caused deterioration in the wearing feeling.

[0005] The present invention is for solving the above problems, and an object thereof is to provide an electrochromic element that suppresses reflection at the interface between the electrode layer and the substrate and does not impair the wearing feeling or the like, and a spectacle lens using the same.

Means for Solving the Problems

[0006] The electrochromic device according to the present invention has a substrate and an electrochromic film disposed on the substrate. The electrochromic film has an electrode layer and an electrochromic layer, and has a layer structure of a second substrate / a second electrode layer / an oxide layer / an electrolyte layer / a reduction layer / a first electrode layer / a first substrate. The first substrate is a polycarbonate substrate, the first electrode layer is a transparent electrode having a film thickness of 123.5 nm or more and 136.5 nm or less, and / or the second substrate is a polycarbonate substrate, and the second electrode layer is a transparent electrode having a film thickness of 120.5 nm or more and 138 nm or less. The refractive indices of the first electrode layer and the second electrode layer are higher than those of the first substrate, the second substrate, the oxide layer, the electrolyte layer, and the reduction layer, and the refractive indices of the oxide layer, the electrolyte layer, and the reduction layer are 1.4 or more and 1.7 or less. The visual reflectance of the first interface between the first electrode layer and the first substrate and the second interface between the second electrode layer and the second substrate is each 1.0% or less.

[0007] In the present invention, the electrode layer is a transparent electrode layer made of ITO, and the visual reflectance of the interface between ITO and the substrate side is preferably 1.0% or less.

[0010] The electrochromic device according to the present invention has a substrate and an electrochromic film disposed on the substrate. The electrochromic film has an electrode layer and an electrochromic layer, and has a layer structure of a second substrate / a second electrode layer / an oxide layer / an electrolyte layer / a reduction layer / a first electrode layer / a first substrate. The first substrate is a plastic substrate having a refractive index of 1.5, the first electrode layer is a transparent electrode having a film thickness of 125 nm or more and 135 nm or less, and / or the second substrate is a plastic substrate having a refractive index of 1.5, and the second electrode layer is a transparent electrode having a film thickness of 124.5 nm or more and 134 nm or less. The refractive indices of the first electrode layer and the second electrode layer are higher than those of the first substrate, the second substrate, the oxide layer, the electrolyte layer, and the reduction layer, and the refractive indices of the oxide layer, the electrolyte layer, and the reduction layer are 1.4 or more and 1.7 or less. The visual reflectance of the first interface between the first electrode layer and the first substrate and the second interface between the second electrode layer and the second substrate is each 1.0% or less.

[0011] The electrochromic element in the present invention has a substrate and an electrochromic film disposed on the substrate. The electrochromic film has an electrode layer and an electrochromic layer, and has a layer structure including a second substrate / a second electrode layer / an oxide layer / an electrolyte layer / a reduction layer / a first electrode layer / a first substrate. The first substrate is a plastic substrate with a refractive index of 1.7. The first electrode layer is a transparent electrode with a film thickness of 125.5 nm or more and 134.5 nm or less, and / or the second substrate is a plastic substrate with a refractive index of 1.7. The second electrode layer is a transparent electrode with a film thickness of 118 nm or more and 140 nm. The refractive indices of the first electrode layer and the second electrode layer are higher than those of the first substrate, the second substrate, the oxide layer, the electrolyte layer, and the reduction layer, and the refractive indices of the oxide layer, the electrolyte layer, and the reduction layer are 1.4 or more and 1.7 or less. The visual reflectance of the first interface between the first electrode layer and the first substrate and the second interface between the second electrode layer and the second substrate are each 1.0% or less.

[0012] In the present invention, an antireflection layer may be provided between the substrate and the electrochromic film.

[0013] The spectacle lens in the present invention is the electrochromic element described above, and the substrate is a lens substrate.

Advantages of the Invention

[0014] According to the electrochromic element of the present invention and the spectacle lens using the same, the visual reflectance of the interface between the electrode layer and the substrate can be controlled to 1.0% or less, and excellent wearing comfort, usability, visibility, etc. can be obtained.

Brief Description of the Drawings

[0015]

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Figure 12

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail.

[0017] <Conventional problems in electrochromic elements and the outline of the present embodiment> An electrochromic element is an element that utilizes an electrochromism phenomenon in which a reversible oxidation-reduction reaction occurs by applying a voltage to both electrodes, and the color changes reversibly. For example, an electrochromic element can be used as a lens for glasses, and can function as sunglasses in a bright place and as clear lenses in a dark place. It is possible to perform a switch operation or automatically adjust to an optimal brightness.

[0018] An electrochromic element has a substrate and an electrochromic film disposed on top of the substrate. Although the layer structure of the electrochromic film is not limited, it includes at least an electrode layer and an electrochromic layer. The electrode layer is in contact with the substrate or is disposed on the substrate surface via a functional layer such as an antireflection layer.

[0019] The characteristics required for the electrode layer include being transparent, having a high transmittance, and being excellent in conductivity. In order to satisfy such characteristics, the electrode layer is a transparent electrode layer, and in particular, ITO (Indium Tin Oxide) is preferably used.

[0020] By the way, among electrochromic films, it has been found that strong reflection occurs at the interface between the transparent electrode layer and the substrate side because the refractive index of the transparent electrode layer is higher than that of other material layers. Regarding reflection, the visual reflectance can be used as an index, and this visual reflectance has conventionally been a high value of about 3% to 5%.

[0021] When having such a high visual reflectance, for example, when an electrochromic element is used as a lens for glasses, the strong reflection has been a cause of deterioration in the wearing feeling.

[0022] Therefore, as a result of intensive research, the present inventor has found that, for example, by adjusting the film thickness of the electrode layer, the apparent reflectance can be made sufficiently lower than the conventional level. That is, in the electrochromic element of the present embodiment, it is possible to control the apparent reflectance at the interface between the electrode layer and the substrate side to 1.0% or less. Hereinafter, the layer configuration of the electrochromic element in the present embodiment will be specifically described.

[0023] <Electrochromic Element 10 in the First Embodiment> FIG. 1 is a schematic cross-sectional view of an electrochromic element 10 in the first embodiment of the present invention.

[0024] The electrochromic element 10 includes a pair of first substrate 1 and second substrate 2, and an electrochromic film 3 sandwiched between the first substrate 1 and the second substrate 2.

[0025] The electrochromic film 3 includes a pair of first electrode layer 4 and second electrode layer 5, and an electrochromic layer 6 provided between the first electrode layer 4 and the second electrode layer 5. Further, the electrochromic layer 6 includes a reduction layer 7 disposed on the first electrode layer 4 side, an oxidation layer 8 disposed on the second electrode layer 5 side, and an electrolyte layer 9 provided between the reduction layer 7 and the oxidation layer 8.

[0026] As shown in FIG. 1, the first electrode layer 4 is in contact with the first substrate 1, and the interface between the first electrode layer 4 and the first substrate 1 is referred to as the "first interface 11". Also, the second electrode layer 5 is in contact with the second substrate 2, and the interface between the second electrode layer 5 and the second substrate 2 is referred to as the "second interface 12".

[0027] [Features of the Electrochromic Element 10 in the First Embodiment] In the electrochromic element 10 shown in FIG. 1, the apparent reflectance of the first interface 11 and the second interface 12 is 1.0% or less, respectively. The apparent reflectance Rv is measured according to JIS T 7334:2011.

[0028] In the first embodiment, each of the substrates 1 and 2 is formed of a polycarbonate (PC) substrate. The thickness of the polycarbonate substrate is not limited, but is about several hundred μm. Also, each of the electrode layers 4 and 5 is formed of ITO. The refractive index of the polycarbonate substrate is about 1.55, and the refractive index of ITO is about 2.0. Also, the refractive indices of the reduction layer 7, the oxidation layer 8, and the electrolyte layer 9 are less than 2.0, specifically, about 1.4 to 1.7. Thus, the refractive index of ITO is the largest among those of the electrochromic film 3.

[0029] As shown in the experiment described later, when the film thickness of ITO is 100 nm, the apparent reflectance becomes as high as about 3% to 5% at both the first interface 11 and the second interface 12.

[0030] Therefore, in the electrochromic element 10 of the first embodiment, the film thickness of ITO is set to be greater than 100 nm. Since the film thicknesses of the electrode layers 4 and 5 are increased in this direction, excellent electrical characteristics can be maintained.

[0031] In the first embodiment, the film thickness of the first electrode layer 4, that is, ITO on the side of the reduction layer 7, is preferably 123.5 nm or more and 136.5 nm or less. Thereby, the apparent reflectance of the first interface 11 can be suppressed to 1.0% or less.

[0032] Also, in the first embodiment, the film thickness of the second electrode layer 5, that is, ITO on the side of the oxidation layer 8, is preferably 120.5 nm or more and 138 nm or less. Thereby, the apparent reflectance of the second interface 12 can be suppressed to 1.0% or less.

[0033] [Electrochromic layer 6] Existing materials can be used for the reduction layer 7, oxidation layer 8, and electrolyte layer 9 that constitute the electrochromic layer 6.

[0034] The reduction layer 7 is a layer that develops color with a reduction reaction. Existing reducing electrochromic compounds can be used for the reduction layer 7. Without being limited by whether they are organic or inorganic, for example, azobenzene-based, anthraquinone-based, diarylethene-based, dihydropyran-based, dipyridine-based, styryl-based, styrylspiropyran-based, spirooxazine-based, spiropthiopyran-based, thioindigo-based, tetrathiafulvalene-based, terephthalic acid-based, triphenylmethane-based, triphenylamine-based, naphthopyran-based, viologen-based, pyrazoline-based, phenazine-based, phenylenediamine-based, phenoxazine-based, phenothiazine-based, phthalocyanine-based, fluoran-based, fulgide-based, benzopyran-based, metallocene-based, tungsten oxide, molybdenum oxide, iridium oxide, titanium oxide, etc. can be mentioned.

[0035] The oxidation layer 8 is a layer that develops color with an oxidation reaction. Existing oxidizing electrochromic compounds can be used for the oxidation layer 8. Without being limited by whether they are organic or inorganic, for example, it can be selected from a composition containing a radical polymerizable compound having a triarylamine, Prussian blue type complex, nickel oxide, iridium oxide, etc.

[0036] The electrolyte layer 9 has electronic insulation and ion conductivity, and is preferably transparent. The electrolyte layer 9 may be a solid electrolyte, gel-like, liquid-like, etc. It is preferably gel-like in order to maintain high ion conductivity. Without being limited, for example, existing electrolyte materials such as inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, and acids can be used.

[0037] In addition, for the film thickness of each material layer constituting the electrochromic layer 6, existing values that effectively exhibit the electrochromism phenomenon can be selected. Specifically, for example, materials and film thicknesses described in US2019 / 184694, Patent No. 6623507, Japanese Patent Application Laid-Open No. 2018-132718, etc. can be appropriately selected and used. Further, the refractive index of the materials described in the above publications, etc. can be confirmed on the Cheimcal Book website (https: / / www.chemicalbook.com / ProductIndex_JP.aspx), etc.

[0038] <The electrochromic element 20 in the second embodiment> In the electrochromic element 20 shown in FIG. 2, substrates 21 and 22 made of materials different from those in FIG. 1 are arranged at both ends of the electrochromic film 3 shown in FIG. 1.

[0039] Each of the substrates 21 and 22 is made of glass or a plastic lens. Other than polycarbonate resin, resins such as acrylic resin, polyethylene resin, polyvinyl chloride resin, polyester resin, epoxy resin, melamine resin, phenol resin, polyurethane resin, and polyimide resin can be used.

[0040] For example, in the electrochromic element 20 shown in FIG. 2, a diethylene glycol bisallyl carbonate-based lens (refractive index = 1.5; manufactured by HOYA Corporation, "HL") or a polysulfide-based plastic lens (refractive index = 1.7; manufactured by HOYA Corporation, "EYRY") can be used for each of the substrates 21 and 22.

[0041] Also in the electrochromic element 20 shown in FIG. 2, the visual reflectance of the first interface 23 between the first substrate 21 and the first electrode layer 4 and the second interface 24 between the second substrate 22 and the second electrode layer 5 is 1.0% or less, respectively.

[0042] In this embodiment, by adjusting the film thicknesses of the first electrode layer 4 and the second electrode layer 5, it is possible to control the apparent reflectance of the first interface 23 and the second interface 24 to be 1.0% or less.

[0043] For example, when using a lens substrate with a refractive index of 1.5 (the "HL" manufactured by the above-mentioned Hoya Corporation) for each of the substrates 21 and 22, the film thickness of the ITO (the first electrode layer 4) on the reduction layer 7 side is preferably 125 nm or more and 135 nm or less. Also, the film thickness of the ITO (the second electrode layer 5) on the oxidation layer 8 side is preferably 124.5 nm or more and 134 nm or less. Thereby, the apparent reflectances of the first interface 23 and the second interface 24 can be suppressed to 1.0% or less, respectively.

[0044] Also, when using a lens substrate with a refractive index of 1.7 (the "EYRY" manufactured by the above-mentioned Hoya Corporation) for each of the substrates 21 and 22, the film thickness of the ITO (the first electrode layer 4) on the reduction layer 7 side is preferably 125.5 nm or more and 134.5 nm or less. Also, the film thickness of the ITO (the second electrode layer 5) on the oxidation layer 8 side is preferably 118 nm or more and 140 nm or less. Thereby, the apparent reflectances of the first interface 23 and the second interface 24 can be suppressed to 1.0% or less, respectively.

[0045] Here, the refractive index of each substrate applied to the electrochromic element is usually about 1.5 to 1.7. Based on the film thicknesses of each ITO described with reference to FIGS. 1 and 2 above, when using a substrate with a refractive index of about 1.5 to 1.7, by adjusting the film thickness of the ITO on the reduction layer side within the range of about 123.5 nm to 136.5 nm, preferably 125 nm to 135 nm, more preferably 125.5 nm to 134.5 nm, the apparent reflectance of the first interface can be suppressed to 1.0% or less. Also, by adjusting the film thickness of the ITO on the oxidation layer side within the range of about 118 nm to 140 nm, preferably 120.5 nm to 138 nm, more preferably 124.5 nm to 134 nm, the apparent reflectance of the second interface can be suppressed to 1.0% or less.

[0046] <Electrochromic Element 30 in the Third Embodiment> In the electrochromic element 30 shown in Fig. 3, substrates 1 and 2 are disposed at both ends of the electrochromic film 3 shown in Fig. 1 via antireflection layers (AR coats) 31 and 32. Each of the antireflection layers 31 and 32 is in contact with both the electrochromic film 3 and the substrates 1 and 2. Each of the antireflection layers 31 and 32 is preferably an inorganic multilayer film in which a high refractive index layer and a low refractive index layer are alternately laminated. Although the material of the high refractive index layer is not limited, for example, it is ZrO2, TiO2, TaO2, NbO2, etc., and in particular, ZrO2 is preferable. Also, although the material of the low refractive index layer is not limited, it is formed of a single layer of SiO2 or a mixed layer containing SiO2, and is preferably a single layer of SiO2. Although not limited, the total number of the high refractive index layer and the low refractive index layer is about 2 to 10 layers.

[0047] Also in the electrochromic element 30 in Fig. 3, similar to the electrochromic elements 10 and 20 shown in Figs. 1 and 2, the visual reflectance of the first interface 33 between the first electrode layer 4 and the first substrate 1 side (corresponding to the interface between the first electrode layer 4 and the antireflection layer 31) and the second interface 34 between the second electrode layer 5 and the second substrate 2 side (corresponding to the interface between the second electrode layer 5 and the antireflection layer 32) is 1.0% or less, respectively.

[0048] In Fig. 3, by adjusting the film configuration of each of the antireflection layers 31 and 32 with respect to the film thickness of each of the electrode layers (ITO) 4 and 5, the visual reflectance can be controlled to 1.0% or less. That is, while forming the electrode layers 4 and 5 with a film thickness at which the electrochromic phenomenon is appropriately exhibited, the film configuration of the antireflection layers 31 and 32 can be adjusted so that the visual reflectance becomes 1.0% or less.

[0049] <Use> Although the use of the electrochromic element of the present embodiment is not limited, it can be preferably applied to dimming spectacle lenses. In the spectacle lens, the first substrate and the second substrate are lens substrates, or the second substrate on the oxide layer side is a lens substrate, and the first substrate 1 functions as a protective layer (hard coat layer). In the present embodiment, the visual reflectance of the first interface and the second interface can be made 1.0% or less respectively. When used as a spectacle lens, reflection can be effectively suppressed and the wearing feeling can be enhanced.

[0050] The electrochromic element of the present embodiment may be applied to other than spectacle lenses. For example, an electrochromic dimming device, an anti-glare mirror, etc. Even when applied to these uses, since the visual reflectance can be made 1.0% or less, excellent wearing feeling, usability, or visibility can be obtained.

[0051] <In addition> In each of the above embodiments, the same material is used for the first substrate on the reduction layer 7 side and the second substrate on the oxide layer 8 side, but substrates of different materials may be used. For example, a polycarbonate substrate can be used for the first substrate, and a lens substrate with a refractive index of 1.5 can be used for the second substrate. In such a case, by forming with the film thickness of each ITO with respect to the substrate materials listed above, the visual reflectance of each interface can be suppressed to 1.0% or less. Further, the substrate may be disposed on only one side of the electrochromic element. That is, in such a case, a substrate is disposed on one side of the electrochromic element, but on the other side, the substrate is not present and the electrode layer is exposed.

[0052] Further, the electrochromic film 3 only needs to have at least one electrode layer and an electrochromic layer 6. Even in this case, the visual reflectance of the interface between the substrate and the electrode layer is controlled to 1.0% or less.

[0053] In addition, in each of the above embodiments, ITO is used as the electrode layer, but a transparent electrode layer other than ITO may also be used. For example, FTO (Fluorine-doped Tin Oxide), ATO (Antimony doped Tin Oxide), etc. can be used as the transparent electrode layer. FTO and ATO have refractive indices approximately the same as that of ITO. By applying the film thickness of ITO described in each of the above embodiments to the film thickness of each electrode layer, the visual reflectance of the first interface and the second interface can be controlled to be 1.0% or less.

[0054] The electrochromic element in this embodiment may be flat or curved. Regardless of the shape of the electrochromic element, a visual reflectance of 1.0% or less can be obtained.

Example

[0055] Hereinafter, this embodiment will be described more specifically using examples and comparative examples. <Experiment using the film configuration of the electrochromic element 10 of the first embodiment> The laminated structure of the electrochromic element shown in FIG. 1 was configured with a substrate film thickness of 300 μm, a reduction layer film thickness of 3 μm, an oxidation layer film thickness of 1.5 μm, and an electrolyte layer film thickness of 50 μm. The electrode layer had the film thicknesses shown in Table 1 and Table 2.

[0056] A polycarbonate substrate (refractive index = 1.59) was used for the substrate, and ITO (refractive index = 2.1) was used for the electrode layer. Also, although not limited, a viologen-based compound (refractive index = 1.45) was used for the reduction layer, a triarylamine compound (refractive index = 1.64) was used for the oxidation layer, and an organic gel substance (a mixture of a plurality of organic salts and a polymer, refractive index = 1.50) was used for the electrolyte layer.

[0057] The film thickness of ITO on the reduction layer side was changed to 100 nm, 123.5 nm, 130 nm, and 136.5 nm, and the film thickness of ITO on the oxidation layer side was changed to 100 nm, 120.5 nm, 130 nm, and 138 nm.

[0058] In the experiment, using a spectroscopic reflectometer USPM manufactured by Olympus Corporation, the spectroscopic reflection spectra of the interfaces between each PC substrate and each ITO at wavelengths from 380 nm to 780 nm were measured. The experimental results are shown in FIGS. 4 and 5. FIG. 4 shows the spectroscopic reflection characteristics of the first interface measured by varying the ITO film thickness on the reduction layer side, and FIG. 5 shows the spectroscopic reflection characteristics of the second interface measured by varying the ITO film thickness on the oxidation layer side.

[0059] As shown in FIGS. 4 and 5, it was found that as the ITO film thickness was increased from 100 nm, the spectroscopic reflection spectrum shifted to the longer wavelength side. That is, as shown in FIGS. 4 and 5, when the ITO film thickness is 100 nm, the wavelength at which the spectroscopic reflectance becomes 0% is about 450 nm, and the spectroscopic reflectance in the wavelength band of about 550 nm to 580 nm is as high as about 4%. However, when the ITO film thickness is increased, it was found that the peak at which the spectroscopic reflectance becomes 0% can be shifted in the wavelength band of about 530 nm to 580 nm.

[0060] Next, the apparent reflectances of the first interface and the second interface were calculated according to JIS T 7334:2011 using the spectroscopic reflectances measured in FIGS. 4 and 5. The experimental results are shown in Tables 1 and 2.

[0061] [Table 1]

[0062] [Table 2]

[0063] Table 1 shows the relationship between the ITO film thickness on the reduction layer side and the apparent reflectance of the first interface. Table 2 shows the relationship between the ITO film thickness on the oxidation layer side and the apparent reflectance of the second interface.

[0064] As shown in Table 1, it was found that when the film thickness of ITO on the reduction layer side was 100 nm, the apparent reflectance of the first interface became 4.61, which was very large. On the other hand, when the film thickness of ITO was set to be 123.5 nm or more and 136.5 nm or less, it was found that the apparent reflectance of the first interface could be suppressed to 1.0% or less.

[0065] Also, as shown in Table 2, it was found that when the film thickness of ITO on the oxidation layer side was 100 nm, the apparent reflectance of the second interface became 3.66, which was very large. On the other hand, when the film thickness of ITO was set to be 120.5 nm or more and 138 nm or less, it was found that the apparent reflectance of the second interface could be suppressed to 1.0% or less.

[0066] <Experiment using the film structure of the electrochromic element 20 of the second embodiment> The laminated structure of the electrochromic element shown in FIG. 2 was configured with a substrate film thickness of 300 μm, a reduction layer film thickness of 3 μm, an oxidation layer film thickness of 1.5 μm, and an electrolyte layer film thickness of 50 μm. The film thickness of the electrode layer was the film thickness described in Tables 3 to 6. As the substrate, “1.5 substrate” or “1.7 substrate” was used. The “1.5 substrate” is a diethylene glycol bisallyl carbonate-based lens (refractive index = 1.5; “HL” manufactured by HOYA Corporation). The “1.7 substrate” is a polysulfide-based plastic lens (refractive index = 1.7; “EYRY” manufactured by HOYA Corporation).

[0067] ITO (refractive index = 2.1) was used for the electrode layer. Although not limited, a viologen-based compound was used for the reduction layer, a triarylamine compound was used for the oxidation layer, and an organic gel substance (a mixture of a plurality of organic salts and a polymer) was used for the electrolyte layer.

[0068] In the experiment, the film thickness of ITO on the reduction layer side of the electrochromic element using the 1.5 substrate was changed to 100 nm, 125 nm, 130 nm, and 135 nm, and the film thickness of ITO on the oxidation layer side was changed to 100 nm, 124.5 nm, 129 nm, and 134 nm.

[0069] The spectral reflectance spectrum was measured by the method described above. The experimental results are shown in FIGS. 6 and 7. FIG. 6 shows the spectral reflectance characteristics of the first interface measured by varying the ITO film thickness on the reduction layer side, and FIG. 7 shows the spectral reflectance characteristics of the second interface measured by varying the ITO film thickness on the oxidation layer side.

[0070] As shown in FIGS. 6 and 7, when the ITO film thickness was 100 nm, the spectral reflectance became 0% at a wavelength of about 450 nm, and the spectral reflectance was 4% or more in the wavelength band of 530 nm to 580 nm. On the other hand, when the ITO film thickness was about 125 nm to 135 nm, it was found that the peak at which the spectral reflectance became 0% could be shifted to the wavelength band of about 530 nm to 580 nm.

[0071] Next, the apparent reflectance of the first interface and the second interface was calculated according to JIS T 7334:2011 using the spectral reflectance measured in FIGS. 6 and 7. The experimental results are shown in Tables 3 and 4.

[0072] Table 3 shows the relationship between the ITO film thickness on the reduction layer side in the electrochromic device using a 1.5 substrate and the apparent reflectance of the first interface. Table 4 shows the relationship between the ITO film thickness on the oxidation layer side in the electrochromic device using a 1.5 substrate and the apparent reflectance of the second interface.

[0073]

Table 3

[0074]

Table 4

[0075] As shown in Table 3, when the ITO film thickness on the reduction layer side was 100 nm, the apparent reflectance of the first interface was found to be 5.44, which was very large. On the other hand, when the ITO film thickness was set to 125 nm or more and 135 nm or less, it was found that the apparent reflectance of the first interface could be suppressed to 1.0% or less.

[0076] Also, as shown in Table 4, when the film thickness of ITO on the oxide layer side is 100 nm, the apparent reflectance of the second interface becomes 4.48, which is found to be very large. On the other hand, when the film thickness of ITO is set to be 124.5 nm or more and 134 nm or less, it is found that the apparent reflectance of the second interface can be suppressed to 1.0% or less.

[0077] Next, in the experiment, the film thickness of ITO on the reduction layer side of the electrochromic element using Substrate 1.7 was changed to 100 nm, 125.5 nm, 130 nm, and 134.5 nm, and the film thickness of ITO on the oxide layer side was changed to 100 nm, 118 nm, 130 nm, and 140 nm.

[0078] The spectral reflectance spectrum was measured by the method described above. The experimental results are shown in FIGS. 8 and 9. FIG. 8 shows the spectral reflection characteristics of the first interface measured by varying the ITO film thickness on the reduction layer side, and FIG. 9 shows the spectral reflection characteristics of the second interface measured by varying the ITO film thickness on the oxide layer side.

[0079] As shown in FIGS. 8 and 9, when the ITO film thickness is 100 nm, the spectral reflectance is about 0.5% or less at a wavelength of about 450 nm, and in the wavelength band of 530 m to 580 nm, the spectral reflectance is 3% or more. On the other hand, when the ITO film thickness is about 120 nm to 140 nm, it is found that the lowest peak (0.5% or less) of the spectral reflectance can be shifted to the wavelength band of about 530 nm to 580 nm.

[0080] Next, the apparent reflectances of the first interface and the second interface were calculated according to JIS T 7334:2011 using the spectral reflectances measured in FIGS. 8 and 9. The experimental results are shown in Tables 5 and 6.

[0081] Table 5 shows the relationship between the film thickness of ITO on the reduction layer side and the apparent reflectance of the first interface in the electrochromic device using a 1.7 substrate. Table 6 shows the relationship between the film thickness of ITO on the oxidation layer side and the apparent reflectance of the second interface in the electrochromic device using a 1.7 substrate.

[0082]

Table 5

[0083]

Table 6

[0084] As shown in Table 5, when the film thickness of ITO on the reduction layer side is 100 nm, the apparent reflectance of the first interface becomes 3.87, which is found to be very large. On the other hand, when the film thickness of ITO is set to be 125.5 nm or more and 134.5 nm or less, it is found that the apparent reflectance of the first interface can be suppressed to 1.0% or less.

[0085] Also, as shown in Table 6, when the ITO film thickness on the oxidation layer side is 100 nm, the apparent reflectance of the second interface becomes 2.93, which is found to be very large. On the other hand, when the film thickness of ITO is set to be 118 nm or more and 140 nm or less, it is found that the apparent reflectance of the second interface can be suppressed to 1.0% or less.

[0086] <Experiment using the film structure of the electrochromic device 20 of the third embodiment> The laminated structure of the electrochromic device shown in FIG. 3 was laminated with the film thicknesses shown in Table 7 below.

[0087]

Table 7

[0088] Table 7 shows the film structure of the entire third electrochromic element 30. The material compositions and film thicknesses of the respective material layers constituting the AR layer, and the film thickness of the electrode layer are shown in Tables 8 and 9.

[0089] Note that a polycarbonate substrate was used for each substrate, and ITO was used for each electrode layer. Also, although not limited, a viologen-based compound was used for the reduction layer, a triarylamine compound was used for the oxidation layer, and an organic gel substance (a mixture of a plurality of organic salts and a polymer) was used for the electrolyte layer. The refractive indices of the substrate, electrode layer, reduction layer, oxidation layer, and electrolyte layer are the same as those in the first embodiment.

[0090] In the experiment, the film thickness of ITO on the reduction layer side was changed to 100 nm (Example 1), 123.5 nm (Example 2), 130 nm (Example 3), and 136.5 nm (Example 4), and the film thickness of ITO on the oxidation layer side was changed to 100 nm (Example 5), 120 nm (Example 6), 130 nm (Example 7), and 138 nm (Example 8).

[0091] FIG. 10 shows the spectroscopic reflection characteristics of a form without an antireflection layer (comparative example) and a form provided with an antireflection layer (Examples 1 and 5) in an electrochromic element in which the film thickness of ITO on the reduction layer side and the film thickness of ITO on the oxidation layer side are each fixed at 100 nm. As shown in FIG. 10, in Comparative Example 1, the wavelength at which the spectroscopic reflectance becomes 0% is about 430 nm to 450 nm, and it was found that the spectroscopic reflectance becomes 3% or more at wavelengths of 530 nm to 580 nm. On the other hand, in Examples 1 and 5, it was found that the wavelength at which the spectroscopic reflectance becomes 0% shifts to about 530 nm to 580 nm.

[0092] FIG. 11 shows the spectroscopic reflection characteristics of the first interface in Examples 1 to 4 measured by variously changing the ITO film thickness on the reduction layer side, and FIG. 12 shows the spectroscopic reflection characteristics of the second interface in Examples 5 to 8 measured by variously changing the ITO film thickness on the oxidation layer side.

[0093] As shown in FIGS. 11 and 12, in the electrochromic elements of Examples 1 to 8 having an antireflection layer, it was found that regardless of the film thickness of ITO, the spectral reflectance at wavelengths of 530 nm to 580 nm could be very low. That is, as can be seen from FIGS. 11 and 12, the film configuration of the antireflection layer was appropriately adjusted according to the film thickness of ITO so that the spectral reflectance became almost 0% over the wavelength band of 530 nm to 580 nm.

[0094] Next, the visual reflectance of the first interface and the second interface was calculated according to JIS T 7334:2011 using the spectral reflectance measured in FIGS. 11 and 12. The experimental results are shown in Tables 8 and 9.

[0095]

Table 8

[0096]

Table 9

[0097] As shown in Table 8, in the configuration having an antireflection layer on the reduction layer side, by appropriately adjusting the film configuration of the antireflection layer with respect to the film thickness of ITO, the visual reflectance of the first interface could be suppressed to 1.0% or less, preferably 0.75% or less. Although not limited, the film thickness of ITO can be adjusted in the range of 100 nm to 136.5 nm. When the film thickness of ITO is in the range of 100 nm to 136.5 nm, the film configuration of the antireflection layer is a laminated structure of SiO2 and ZrO2, and the film thickness of SiO2 in contact with the first substrate (PC) is formed to be the thickest in the antireflection layer. Specifically, it is 140 nm or more and 200 m or less. Also, the film thickness of ZrO2 is thinner than that of SiO2 and is about 2 nm to 30 m. The total number of antireflection layers is two or three. When it is three layers, the film thickness of SiO2 in contact with the first electrode layer (ITO) is formed to be about 10 nm to 60 nm.

[0098] Also, in the configuration having an antireflection layer on the oxide layer side shown in Table 9, by adjusting the film configuration of the antireflection layer with respect to the film thickness of ITO, the visual reflectance of the second interface could be suppressed to 1.0% or less, preferably 0.45% or less. Although not limited, the film thickness of ITO can be adjusted in the range of 100 nm to 138 nm. When the film thickness of ITO is in the range of 100 nm to 138 nm, the film configuration of the antireflection layer is a laminated structure of SiO2 and ZrO2, and the film thickness of SiO2 in contact with the first substrate (PC) is formed to be the thickest in the antireflection layer. Specifically, it is 50 nm or more and 100 m or less. The film thickness of ZrO2 is thinner than that of SiO2 and is about 5 nm to 30 m. The total number of antireflection layers is preferably 3 or 4 layers.

Industrial Applicability

[0099] The electrochromic element of the present invention can suppress the visual reflectance to 1.0% or less. Since the reflection can be suppressed low in this way, when the electrochromic element is used as a lens for, for example, dimming glasses, excellent wearability can be obtained.

Explanation of Symbols

[0100] This application is based on Japanese Patent Application No. 2020-176814 filed on October 21, 2020. All of this content is incorporated herein.

Claims

1. a substrate, an electrochromic film disposed on top of the substrate, and having, the electrochromic film has an electrode layer and an electrochromic layer, a layer structure having a second substrate / a second electrode layer / an oxide layer / an electrolyte layer / a reduction layer / a first electrode layer / a first substrate, the first substrate is a polycarbonate substrate, and the first electrode layer is a transparent electrode having a film thickness of 123.5 nm or more and 136.5 nm or less, and / or, the second substrate is a polycarbonate substrate, and the second electrode layer is a transparent electrode having a film thickness of 120.5 nm or more and 138 nm or less, the refractive indices of the first electrode layer and the second electrode layer are higher than the refractive indices of the first substrate, the second substrate, the oxide layer, the electrolyte layer, and the reduction layer, and the refractive indices of the oxide layer, the electrolyte layer, and the reduction layer are 1.4 or more and 1.7 or less, an electrochromic device, characterized in that the visual reflectance of the first interface between the first electrode layer and the first substrate and the second interface between the second electrode layer and the second substrate is 1.0% or less, respectively.

2. a substrate, an electrochromic film disposed on top of the substrate, and having, the electrochromic film has an electrode layer and an electrochromic layer, a layer structure having a second substrate / a second electrode layer / an oxide layer / an electrolyte layer / a reduction layer / a first electrode layer / a first substrate, the first substrate is a plastic substrate having a refractive index of 1.5, and the first electrode layer is a transparent electrode having a film thickness of 125 nm or more and 135 nm or less, and / or, the second substrate is a plastic substrate having a refractive index of 1.5, and the second electrode layer is a transparent electrode having a film thickness of 124.5 nm or more and 134 nm or less, the refractive indices of the first electrode layer and the second electrode layer are higher than the refractive indices of the first substrate, the second substrate, the oxide layer, the electrolyte layer, and the reduction layer, and the refractive indices of the oxide layer, the electrolyte layer, and the reduction layer are 1.4 or more and 1.7 or less, an electrochromic device, characterized in that the visual reflectance of the first interface between the first electrode layer and the first substrate and the second interface between the second electrode layer and the second substrate is 1.0% or less, respectively.

3. a substrate, an electrochromic film disposed on top of the substrate, and having, The electrochromic film has an electrode layer and an electrochromic layer. It has a layer structure including a second substrate / a second electrode layer / an oxide layer / an electrolyte layer / a reduction layer / a first electrode layer / a first substrate. The first substrate is a plastic substrate with a refractive index of 1.7, and the first electrode layer is a transparent electrode with a film thickness of 125.5 nm or more and 134.5 nm or less. And / or The second substrate is a plastic substrate with a refractive index of 1.7, and the second electrode layer is a transparent electrode with a film thickness of 118 nm or more and 140 nm. The refractive indices of the first electrode layer and the second electrode layer are higher than those of the first substrate, the second substrate, the oxide layer, the electrolyte layer, and the reduction layer, and the refractive indices of the oxide layer, the electrolyte layer, and the reduction layer are 1.4 or more and 1.7 or less. An electrochromic device, characterized in that the visual reflectance of a first interface between the first electrode layer and the first substrate and a second interface between the second electrode layer and the second substrate is 1.0% or less, respectively.

4. The electrode layer is a transparent electrode layer made of ITO, and the visual reflectance of the interface between the ITO and the substrate side is 1.0% or less. The electrochromic device according to any one of claims 1 to 3.

5. The electrochromic device according to any one of claims 1 to 4, characterized in that an antireflection layer is provided between the substrate and the electrochromic film.

6. An electrochromic device according to any one of claims 1 to 5, wherein the substrate is a lens substrate, and a spectacle lens characterized by this.

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