Electrochromic element and ophthalmic lens

Abstract

The present application aims to provide an electrochromic element that suppresses reflection at the interface between an electrode layer and a substrate, and does not impair the wearing feeling, and an eyeglass lens using the electrochromic element. The electrochromic element (10) of the present application has a substrate (1, 2) and an electrochromic film (3) disposed in superposition with the substrate, the electrochromic film having an electrode layer (4, 5) and an electrochromic layer (6), the light reflectance at the interface (11, 12) between the electrode layer and the substrate side being 1.0% or less. It is preferable that the electrode layer be a transparent electrode layer formed of ITO, and the light reflectance at the interface between the ITO and the substrate side be 1.0% or less.

Description

Technical Field

[0001] The present invention relates to an electrochromic element capable of reversibly controlling color rendering and decolorization by electricity, and an eyeglass lens using the electrochromic element. Background Technology

[0002] Electrochromic elements, which utilize the electrochromic phenomenon of reversible oxidation-reduction reactions that occur when voltage is applied, causing reversible color changes, can be used, for example, as lenses for eyeglasses. An electrochromic element is constructed by depositing an electrochromic film having an electrode layer and an electrochromic layer on the surface of a substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-111389

[0006] Patent Document 2: Japanese Patent Application Publication No. 2013-101309 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] As described in Patent Documents 1 and 2, the electrode layer is generally a transparent electrode layer formed of ITO, etc. However, the refractive index of the transparent electrode layer is higher than that of other material layers in the electrochromic film, resulting in strong reflection at the interface between the electrode layer and the substrate. Therefore, for example, if a highly reflective electrochromic element is used as a lens for eyeglasses, it will lead to a decrease in wearing comfort.

[0009] The present invention addresses the above-mentioned problems and aims to provide an electrochromic element that suppresses reflection at the interface between the electrode layer and the substrate without compromising wearing comfort, and an eyeglass lens using the electrochromic element.

[0010] Problem Solving Methods

[0011] The electrochromic element of the present invention includes: a substrate and an electrochromic film disposed in superposition with the substrate, the electrochromic film having an electrode layer and an electrochromic layer, and the light reflectance of the interface between the electrode layer and the substrate side is 1.0% or less.

[0012] In this invention, it is preferred that the electrode layer is a transparent electrode layer formed of ITO, and the light reflectance of the interface between ITO and the substrate side is 1.0% or less.

[0013] In this invention, the electrochromic element preferably has a layer structure of second substrate / second electrode layer / oxide layer / electrolyte layer / reduction layer / first electrode layer / first substrate, and the light 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.

[0014] In this invention, it is preferred that the first substrate is a polycarbonate substrate and the first electrode layer is a transparent electrode with 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 with a film thickness of 120.5 nm or more and 138 nm or less.

[0015] In this invention, it is preferred that the first substrate is a plastic substrate with a refractive index of 1.5, and the first electrode layer is a transparent electrode with a film thickness of 125 nm or more and 135 nm or less, and / or the second substrate is a plastic substrate with a refractive index of 1.5, and the second electrode layer is a transparent electrode with a film thickness of 124.5 nm or more and 134 nm or less.

[0016] In this invention, it is preferred that 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 or less.

[0017] In this invention, an anti-reflective layer may be provided between the substrate and the electrochromic film.

[0018] The eyeglass lens of the present invention is the electrochromic element described above, and the substrate is a lens substrate.

[0019] The effects of the invention

[0020] The electrochromic element of the present invention, and the eyeglass lens using the electrochromic element, can control the light reflectance of the interface between the electrode layer and the substrate side to be less than 1.0%, thereby achieving excellent wearing comfort, usability, or visual recognition. Attached Figure Description

[0021] Figure 1 This is a cross-sectional schematic diagram of the electrochromic element in the first embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional schematic diagram of the electrochromic element in the second embodiment of the present invention.

[0023] Figure 3This is a cross-sectional schematic diagram of the electrochromic element in the third embodiment of the present invention.

[0024] Figure 4 This demonstrates the use of a PC substrate. Figure 1 The graph shows the spectral reflectance characteristics of the first interface when the thickness of the first electrode layer changes due to the electrochromic element.

[0025] Figure 5 This demonstrates the use of a PC substrate. Figure 1 The graph shows the spectral reflectance characteristics of the second interface when the thickness of the second electrode layer changes due to the electrochromic element.

[0026] Figure 6 This demonstrates the use of a 1.5mm substrate. Figure 2 The graph shows the spectral reflectance characteristics of the first interface when the thickness of the first electrode layer changes due to the electrochromic element.

[0027] Figure 7 This demonstrates the use of a 1.5mm substrate. Figure 2 The graph shows the spectral reflectance characteristics of the second interface when the thickness of the second electrode layer changes due to the electrochromic element.

[0028] Figure 8 This demonstrates the use of a 1.7-inch substrate. Figure 2 The graph shows the spectral reflectance characteristics of the first interface when the thickness of the first electrode layer changes due to the electrochromic element.

[0029] Figure 9 This demonstrates the use of a 1.7-inch substrate. Figure 2 The graph shows the spectral reflectance characteristics of the second interface when the thickness of the second electrode layer changes due to the electrochromic element.

[0030] Figure 10 It uses a material with an anti-reflective layer. Figure 3 The graph shows the spectral reflectance characteristics of the first and second interfaces of the electrochromic element (example) and the electrochromic element without an anti-reflection layer (comparative example) when the first electrode layer and the second electrode layer are fixed at 100 nm.

[0031] Figure 11 This demonstrates the use of a material with an anti-reflective layer. Figure 3 The graph shows the spectral reflectance characteristics of the first interface when the thickness of the first electrode layer changes due to the electrochromic element.

[0032] Figure 12 This demonstrates the use of a material with an anti-reflective layer. Figure 3 The graph shows the spectral reflectance characteristics of the second interface when the thickness of the second electrode layer changes due to the electrochromic element. Detailed Implementation

[0033] The specific embodiments of the present invention (hereinafter referred to as "this embodiment") will be described in detail below.

[0034] <An overview of existing problems in electrochromic elements and this embodiment>

[0035] Electrochromic elements are devices that utilize the electrochromic phenomenon, where a reversible oxidation-reduction reaction occurs when a voltage is applied to two electrodes, causing a reversible change in color. For example, electrochromic elements can be used as lenses for eyeglasses; in bright light, they can function as sunglasses, and in dark light, they can function as clear lenses. They can be operated by switching on and off to automatically adjust to the optimal brightness.

[0036] An electrochromic element has: a substrate and an electrochromic film disposed in superimposed on the substrate. Although the layer composition of the electrochromic film is not limited, it has at least an electrode layer and an electrochromic layer, wherein the electrode layer is in contact with the substrate or disposed on the surface of the substrate through a functional layer such as an anti-reflective layer.

[0037] The required characteristics of the electrode layer include transparency, high transmittance, and excellent conductivity. To meet these requirements, the electrode layer is a transparent electrode layer, and ITO (Indium Tin Oxide) is particularly preferred.

[0038] However, it is known that in electrochromic films, the refractive index of the transparent electrode layer is higher than that of other material layers, resulting in strong reflection at the interface between the transparent electrode layer and the substrate. The light reflectance can be used as an indicator of reflection, and this reflectance has historically been as high as 3% to 5%.

[0039] If the light reflectance is so high, for example, when an electrochromic element is used as a lens for eyeglasses, the strong reflection will cause a decrease in the wearing comfort.

[0040] Therefore, through in-depth research, the inventors discovered that, for example, by adjusting the film thickness of the electrode layer, the light reflectance can be made sufficiently low compared to conventional methods. That is, in the electrochromic element of this embodiment, the light reflectance at the interface between the electrode layer and the substrate can be controlled to 1.0% or less. The layer structure of the electrochromic element in this embodiment will now be described in detail.

[0041] <Electrochromic element 10 in the first embodiment>

[0042] Figure 1 This is a cross-sectional schematic diagram of the electrochromic element 10 according to the first embodiment of the present invention.

[0043] The electrochromic element 10 is composed of a pair of first substrates 1 and second substrates 2, and an electrochromic film 3 sandwiched between the first substrates 1 and the second substrates 2.

[0044] The electrochromic film 3 has a pair of first electrode layers 4 and second electrode layers 5, and an electrochromic layer 6 disposed between the first electrode layer 4 and the second electrode layer 5. Furthermore, the electrochromic layer 6 is composed of a reduction layer 7 disposed on the side of the first electrode layer 4, an oxide layer 8 disposed on the side of the second electrode layer 5, and an electrolyte layer 9 disposed between the reduction layer 7 and the oxide layer 8.

[0045] like Figure 1 As shown, the first electrode layer 4 is connected to the first substrate 1, and the interface between the first electrode layer 4 and the first substrate 1 is referred to as "first interface 11". In addition, the second electrode layer 5 is connected to the second substrate 2, and the interface between the second electrode layer 5 and the second substrate 2 is referred to as "second interface 12".

[0046] [Features of the electrochromic element 10 in the first embodiment]

[0047] exist Figure 1 In the electrochromic element 10 shown, the light reflectance of the first interface 11 and the second interface 12 is 1.0% or less. The light reflectance Rv is measured according to JIS T 7334:2011.

[0048] In the first embodiment, each substrate 1 and 2 is formed of a polycarbonate (PC) substrate. It should be noted that the thickness of the polycarbonate substrate is not limited, but is approximately several hundred μm. Furthermore, each electrode layer 4 and 5 is formed of ITO. The refractive index of the polycarbonate substrate is approximately 1.55, and the refractive index of ITO is approximately 2.0. Additionally, the refractive indices of the reduction layer 7, oxide layer 8, and electrolyte layer 9 are less than 2.0, specifically approximately 1.4 to 1.7. Thus, the refractive index of ITO is the highest in the electrochromic film 3.

[0049] As shown in the experiment described later, if the thickness of the ITO film is set to 100 nm, the light reflectance of both the first interface 11 and the second interface 12 increases by about 3% to 5%.

[0050] Therefore, in the electrochromic element 10 of the first embodiment, the thickness of the ITO film is set to be thicker than 100 nm. It should be noted that since the direction of increasing the film thickness of the electrode layers 4 and 5 is the direction of maintaining excellent electrical properties.

[0051] In the first embodiment, the thickness of the ITO film on the first electrode layer 4, i.e., the reduction layer 7 side, is preferably 123.5 nm or more and 136.5 nm or less. This allows the light reflectance of the first interface 11 to be suppressed to 1.0% or less.

[0052] Furthermore, in the first embodiment, the thickness of the ITO film on the second electrode layer 5, i.e., the oxide layer 8 side, is preferably 120.5 nm or more and 138 nm or less. This allows the light reflectance of the second interface 12 to be suppressed to 1.0% or less.

[0053] [Electrochromic layer 6]

[0054] The reduction layer 7, oxide layer 8, and electrolyte layer 9 that constitute the electrochromic layer 6 can be made of existing materials.

[0055] The reducing layer 7 is the layer that develops color during the reduction reaction. Existing reducing electrochromic compounds can be used for reducing layer 7. There are no limitations on whether the compound is organic or inorganic; examples include: azobenzenes, anthraquinones, diarylethylenes, dihydroprene, bipyridines, styryl compounds, styrylspiropyrans, and spiropyrans. Azides, spirothianoides, indigo sulfide, tetrathiofulvalene, terephthalic acid, triphenylmethane, triphenylamine, naphthylpyran, violacein, pyrazoline, phenazine, phenylenediamine, phenanthrene Azides, phenothiazines, phthalocyanines, fluorenes, succinic anhydrides, benzopyrans, metallocenes, tungsten oxide, molybdenum oxide, iridium oxide, titanium oxide, etc.

[0056] Oxide layer 8 is a layer that develops color in conjunction with an oxidation reaction. Oxide layer 8 can be made from existing oxidative electrochromic compounds. There are no limitations on whether the compound is organic or inorganic; for example, it can be selected from compositions containing radical polymerizable compounds having a triarylamine, Prussian blue complexes, nickel oxide, iridium oxide, etc.

[0057] The electrolyte layer 9 possesses electronic insulation and ionic conductivity, and is preferably transparent. The electrolyte layer 9 can be a solid electrolyte, a gel, a liquid, etc. To maintain high ionic conductivity, a gel-like form is preferred. While not limited, existing electrolyte materials such as inorganic ionic salts (alkali metal salts, alkaline earth metal salts, etc.), quaternary ammonium salts, and acids can be used.

[0058] It should be noted that the film thickness of each material layer constituting the electrochromic layer 6 can be selected from existing values ​​that effectively utilize the electrochromic phenomenon. Specifically, materials and film thicknesses can be appropriately selected from those described in US2019 / 184694, Japanese Patent No. 6623507, or Japanese Unexamined Patent Application Publication No. 2018-132718. Furthermore, the refractive index of the materials described in the aforementioned publications can be confirmed on the Chemical Book website (https: / / www.chemicalbook.com / ProductIndex_JP.aspx), etc.

[0059] <Electrochromic element 20 in the second embodiment>

[0060] exist Figure 2 In the electrochromic element 20 shown, in Figure 1 The electrochromic film 3 shown has electrodes at both ends that are connected to the electrode. Figure 1 Substrates 21 and 22 made of different materials.

[0061] Each substrate 21 and 22 is made of glass or plastic lens. In addition to polycarbonate resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, polyester resin, epoxy resin, melamine resin, phenolic resin, polyurethane resin, polyimide resin, and other resins can also be used.

[0062] For example, in Figure 2 In the electrochromic element 20 shown, each substrate 21 and 22 can be made of diethylene glycol dielyl carbonate (refractive index = 1.5; manufactured by HOYA Corporation, "HL") or polysulfide plastic (refractive index = 1.7; manufactured by HOYA Corporation, "EYRY").

[0063] exist Figure 2 Similarly, in the electrochromic element 20 shown, the light 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 are both less than 1.0%.

[0064] In this embodiment, by adjusting the film thickness of the first electrode layer 4 and the second electrode layer 5, the light reflectance of the first interface 23 and the second interface 24 can be controlled to be below 1.0%.

[0065] For example, when each substrate 21 and 22 uses a lens substrate with a refractive index of 1.5 (the aforementioned "HL" manufactured by HOYA Corporation), the film thickness of the ITO (first electrode layer 4) on the reduction layer 7 side is preferably 125 nm or more and 135 nm or less. Furthermore, the film thickness of the ITO (second electrode layer 5) on the oxide layer 8 side is preferably 124.5 nm or more and 134 nm or less. As a result, the light reflectance of both the first interface 23 and the second interface 24 can be suppressed to 1.0% or less.

[0066] Furthermore, when each substrate 21 and 22 uses a lens substrate with a refractive index of 1.7 (the aforementioned "EYRY" manufactured by HOYA Corporation), the film thickness of ITO (first electrode layer 4) on the reduction layer 7 side is preferably 125.5 nm or more and 134.5 nm or less. Additionally, the film thickness of ITO (second electrode layer 5) on the oxide layer 8 side is preferably 118 nm or more and 140 nm or less. As a result, the light reflectance of both the first interface 23 and the second interface 24 can be suppressed to 1.0% or less.

[0067] Here, the refractive index of each substrate used in electrochromic elements is typically around 1.5 to 1.7. Based on the above usage... Figure 1 , Figure 2 The ITO film thicknesses described herein, when using a substrate with a refractive index of approximately 1.5 to 1.7, allow for the suppression of the light reflectance at the first interface to be below 1.0% by adjusting the ITO film thickness on the reduction layer side within the range of approximately 123.5 nm to 136.5 nm, preferably 125 nm to 135 nm, and more preferably 125.5 nm to 134.5 nm. Furthermore, by adjusting the ITO film thickness on the oxide layer side within the range of approximately 118 nm to 140 nm, preferably 120.5 nm to 138 nm, and more preferably 124.5 nm to 134 nm, the light reflectance at the second interface can be suppressed to below 1.0%.

[0068] <Electrochromic element 30 in the third embodiment>

[0069] exist Figure 3 In the electrochromic element 30 shown, in Figure 1 The electrochromic film 3 shown has substrates 1 and 2 disposed at both ends separated by antireflective layers (AR coatings) 31 and 32. Each antireflective layer 31 and 32 is in contact with both the electrochromic film 3 and the substrates 1 and 2. Each antireflective layer 31 and 32 is preferably an inorganic multilayer film formed by alternating layers of high-refractive-index and low-refractive-index layers. The material of the high-refractive-index layer is not limited, and can be, for example, ZrO2, TiO2, TaO2, NbO2, etc., with ZrO2 being particularly preferred. Furthermore, the material of the low-refractive-index layer is not limited, and can be formed from a single layer of SiO2 or a mixed layer containing SiO2, with a single layer of SiO2 being preferred. Although not limited, the total number of high-refractive-index and low-refractive-index layers is approximately 2 to 10 layers.

[0070] exist Figure 3 Electrochromotropic pigment 30 is also associated with Figure 1 and Figure 2 Similarly, the light reflectance of the electrochromic elements 10 and 20 shown is less than 1.0% at the first interface 33 (equivalent to the interface between the first electrode layer 4 and the anti-reflection layer 31) on the first substrate 1 side and the second interface 34 (equivalent to the interface between the second electrode layer 5 and the anti-reflection layer 32) on the second substrate 2 side.

[0071] exist Figure 3In this process, regarding the film thickness of each electrode layer (ITO) 4 and 5, by adjusting the film composition of each antireflective layer 31 and 32, the light reflectance can be controlled to below 1.0%. That is, by adjusting the film composition of the antireflective layers 31 and 32, each electrode layer 4 and 5 can be formed with a film thickness that is suitable for the electrochromic phenomenon, and the light reflectance is made to below 1.0%.

[0072] <Uses>

[0073] The application of the electrochromic element in this embodiment is not limited, and it can preferably be applied to light-adjustable eyeglass lenses. In eyeglass lenses, 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 coating). In this embodiment, the light reflectance of the first interface and the second interface can be set to 1.0% or less, which can effectively suppress reflection when used as an eyeglass lens, thereby improving the wearing comfort.

[0074] The electrochromic element of this embodiment can also be applied to applications other than eyeglass lenses. For example, it can be used in electrochromic dimming devices, anti-glare lenses, etc. When applied to these applications, the light reflectance can be set to 1.0% or less, thus achieving excellent wearing comfort, usability, or visual visibility.

[0075] <Other>

[0076] In the embodiments described above, the first substrate on the reduction layer 7 side and the second substrate on the oxide layer 8 side use the same material, but substrates made of different materials can also be used. For example, the first substrate can be a polycarbonate substrate, and the second substrate can be a lens substrate with a refractive index of 1.5. In this case, by forming a film with the same ITO thickness as the materials listed above for the substrates, the light reflectance at each interface can be suppressed to below 1.0%. Furthermore, the substrate can be disposed only on one side of the electrochromic element. That is, in this case, the substrate is disposed on one side of the electrochromic element, and the electrode layer is exposed on the other side without a substrate.

[0077] In addition, the electrochromic film 3 can have at least one electrode layer and an electrochromic layer 6. In this case, the light reflectance at the interface between the substrate and the electrode layer is controlled to be less than 1.0%.

[0078] Furthermore, in the embodiments described above, ITO was used as the electrode layer, but other transparent electrode layers besides ITO can also be used. For example, FTO (fluorine-doped tin oxide) and ATO (antimony-doped tin oxide) can be used as transparent electrode layers. FTO and ATO have a refractive index that is substantially the same as that of ITO. By applying the ITO film thickness described in the embodiments above to the film thickness of each electrode layer, the light reflectance of the first interface and the second interface can be controlled to be 1.0% or less.

[0079] The electrochromic element in this embodiment can be either flat or curved. Regardless of the shape of the electrochromic element, a light reflectance of less than 1.0% can be obtained.

[0080] Example

[0081] The following describes this embodiment in more detail using examples and comparative examples.

[0082] <Experiment using the film structure of the electrochromic element 10 of the first embodiment>

[0083] It is constituted in the following manner Figure 1 The layered structure of the electrochromic element shown is as follows: the substrate thickness is set to 300 μm, the reduction layer thickness is set to 3 μm, the oxide layer thickness is set to 1.5 μm, and the electrolyte layer thickness is set to 50 μm. The electrode layers are set to the thicknesses recorded in Tables 1 and 2.

[0084] The substrate used is a polycarbonate substrate (refractive index = 1.59), and the electrode layer uses ITO (refractive index = 2.1). In addition, although there are no restrictions, the reduction layer uses a violet alkaloid compound (refractive index = 1.45), the oxide layer uses a triarylamine compound (refractive index = 1.64), and the electrolyte layer uses an organic gel-like material (a mixture of multiple organic salts and polymers, refractive index = 1.50).

[0085] The thickness of the ITO film on the reduced layer side was changed to 100nm, 123.5nm, 130nm, and 136.5nm, and the thickness of the ITO film on the oxide layer side was changed to 100nm, 120.5nm, 130nm, and 138nm.

[0086] In the experiment, the spectrophotometric reflectance spectra of the interfaces between each PC substrate and each ITO substrate in the wavelength range of 380 nm to 780 nm were measured using an Olympus USPM spectrophotometer. The experimental results are shown below. Figure 4 , Figure 5 . Figure 4The spectral reflectance characteristics of the first interface were measured by varying the thickness of the ITO film on the reduced layer side. Figure 5 It is the spectral reflectance characteristics of the second interface measured by varying the thickness of the ITO film on the oxide layer side.

[0087] It can be known that... Figure 4 , Figure 5 Therefore, when the ITO film thickness is increased from 100 nm, the spectroscopic reflectance spectrum shifts towards higher wavelengths. That is, as... Figure 4 , Figure 5 As shown, when the ITO film thickness is 100nm, the wavelength at which the spectral reflectance becomes 0% is around 450nm, and the spectral reflectance in the wavelength band of around 550nm to 580nm increases to around 4%. However, if the ITO film thickness is increased, the peak at which the spectral reflectance becomes 0% can shift to the wavelength band of around 530nm to 580nm.

[0088] Next, use in Figure 4 , Figure 5 The spectral reflectance was measured, and the light reflectance ratios of the first and second interfaces were calculated according to JIS T 7334:2011. The experimental results are shown in Tables 1 and 2.

[0089] [Table 1]

[0090] Light reflectance ITO 100nm 4.61 ITO 123.5nm 0.99 ITO 130nm 0.78 ITO 136.5nm 0.98

[0091] [Table 2]

[0092] Light reflectance ITO 100nm 3.66 ITO 120.5nm 0.96 ITO 130nm 0.66 ITO 138nm 0.96

[0093] Table 1 shows the relationship between the ITO film thickness on the reduced layer side and the light reflectance of the first interface. Table 2 shows the relationship between the ITO film thickness on the oxide layer side and the light reflectance of the second interface.

[0094] As shown in Table 1, it can be seen that when the ITO film thickness on the reduction layer side is 100 nm, the light reflectance of the first interface becomes 4.61, which is very large. On the other hand, it can be seen that when the ITO film thickness is set to 123.5 nm or more and 136.5 nm or less, the light reflectance of the first interface can be suppressed to below 1.0%.

[0095] Furthermore, as shown in Table 2, it can be seen that when the ITO film thickness on the oxide layer side is 100 nm, the light reflectance of the second interface becomes 3.66, which is very high. On the other hand, it can be seen that if the ITO film thickness is set to 120.5 nm or more and 138 nm or less, the light reflectance of the second interface can be suppressed to below 1.0%.

[0096] <Experiment using the film structure of the electrochromic element 20 according to the second embodiment>

[0097] It is constituted in the following manner Figure 2 The layered structure of the electrochromic element shown is as follows: the substrate thickness is 300 μm, the reduction layer thickness is 3 μm, the oxide layer thickness is 1.5 μm, and the electrolyte layer thickness is 50 μm. The electrode layer thickness is set as described in Tables 3 to 6. The substrate used is either a "1.5 substrate" or a "1.7 substrate". "1.5 substrate" refers to a diethylene glycol dielyl carbonate lens (refractive index = 1.5; manufactured by HOYA Co., Ltd., "HL"). "1.7 substrate" refers to a polysulfide plastic lens (refractive index = 1.7; manufactured by HOYA Co., Ltd., "EYRY").

[0098] The electrode layer uses ITO (refractive index = 2.1). In addition, although there are no restrictions, the reduction layer uses a violet alkaloid compound, the oxide layer uses a triarylamine compound, and the electrolyte layer uses an organic gel-like material (a mixture of multiple organic salts and polymers).

[0099] In the experiment, the ITO film thickness on the reduction layer side of the electrochromic element using a 1.5mm substrate was changed to 100nm, 125nm, 130nm, and 135nm, and the ITO film thickness on the oxide layer side was changed to 100nm, 124.5nm, 129nm, and 134nm.

[0100] The spectrophotometric reflectance spectrum was determined using the method described above. The experimental results are shown below. Figure 6 , Figure 7 . Figure 6 The spectral reflectance characteristics of the first interface were measured by varying the thickness of the ITO film on the reduced layer side. Figure 7 It is the spectral reflectance characteristics of the second interface measured by varying the thickness of the ITO film on the oxide layer side.

[0101] like Figure 6 , Figure 7 As shown, when the ITO film thickness is 100 nm, the spectral reflectance becomes 0% at around 450 nm, and the spectral reflectance is above 4% in the wavelength band of 530 nm to 580 nm. On the other hand, it can be seen that if the ITO film thickness is set to about 125 nm to 135 nm, the peak of 0% spectral reflectance can be shifted to the wavelength band of about 530 nm to 580 nm.

[0102] Next, use in Figure 6 , Figure 7 The spectral reflectance was measured, and the light reflectance ratios of the first and second interfaces were calculated according to JIS T 7334:2011. The experimental results are shown in Tables 3 and 4.

[0103] Table 3 shows the relationship between the ITO film thickness on the reduction layer side and the light reflectance of the first interface in an electrochromic element using a 1.5mm substrate. Table 4 shows the relationship between the ITO film thickness on the oxide layer side and the light reflectance of the second interface in an electrochromic element using a 1.5mm substrate.

[0104] [Table 3]

[0105] Light reflectance ITO 100nm 5.44 ITO 125nm 0.99 ITO 130nm 0.84 ITO 135nm 0.99

[0106] [Table 4]

[0107] Light reflectance ITO 100nm 4.48 ITO 124.5nm 0.98 ITO 129nm 0.87 ITO 134nm 0.99

[0108] As shown in Table 3, when the ITO film thickness on the reduced layer side is 100 nm, the light reflectance at the first interface becomes 5.44, which is very high. Conversely, if the ITO film thickness is set to be above 125 nm and below 135 nm, the light reflectance at the first interface can be suppressed to below 1.0%.

[0109] Furthermore, as shown in Table 4, it can be seen that when the ITO film thickness on the oxide layer side is 100 nm, the light reflectance of the second interface becomes 4.48, which is very high. In contrast, it can be seen that when the ITO film thickness is set to 124.5 nm or more and 134 nm or less, the light reflectance of the second interface can be suppressed to below 1.0%.

[0110] Next, in the experiment, the thickness of the ITO film on the reduction layer side of the electrochromic element using a 1.7 substrate was changed to 100nm, 125.5nm, 130nm, and 134.5nm, and the thickness of the ITO film on the oxide layer side was changed to 100nm, 118nm, 130nm, and 140nm.

[0111] The spectrophotometric reflectance spectrum was determined using the method described above. The experimental results are shown below. Figure 8 , Figure 9 . Figure 8 The spectral reflectance characteristics of the first interface were measured by varying the thickness of the ITO film on the reduced layer side. Figure 9 It is the spectral reflectance characteristics of the second interface measured by varying the thickness of the ITO film on the oxide layer side.

[0112] like Figure 8 , Figure 9As shown, when the ITO film thickness is 100 nm, the spectral reflectance is less than 0.5% at around 450 nm, and more than 3% in the wavelength band of 530 nm to 580 nm. On the other hand, if the ITO film thickness is set to approximately 120 nm to 140 nm, the lowest peak of spectral reflectance (less than 0.5%) can be shifted to the wavelength band of approximately 530 nm to 580 nm.

[0113] Next, use in Figure 8 , Figure 9 The spectral reflectance was measured, and the light reflectance ratios of the first and second interfaces were calculated according to JIS T 7334:2011. The experimental results are shown in Tables 5 and 6.

[0114] Table 5 shows the relationship between the ITO film thickness on the reduction layer side and the light reflectance of the first interface in an electrochromic element using a 1.7 substrate. Table 6 shows the relationship between the ITO film thickness on the oxide layer side and the light reflectance of the second interface in an electrochromic element using a 1.7 substrate.

[0115] [Table 5]

[0116] Light reflectance ITO 100nm 3.87 ITO 125.5nm 0.99 ITO 130nm 0.92 ITO 134.5nm 0.99

[0117] [Table 6]

[0118] Light reflectance ITO 100nm 2.93 ITO 118nm 1.00 ITO 130nm 0.62 ITO 140nm 0.98

[0119] As shown in Table 5, it can be seen that when the ITO film thickness on the reduced layer side is 100 nm, the light reflectance of the first interface becomes 3.87, which is very high. In contrast, it can be seen that if the ITO film thickness is set to be above 125.5 nm and below 134.5 nm, the light reflectance of the first interface can be suppressed to below 1.0%.

[0120] Furthermore, as shown in Table 6, it can be seen that when the ITO film thickness on the oxide layer side is 100 nm, the light reflectance at the second interface becomes 2.93, which is very high. In contrast, if the ITO film thickness is set to 118 nm or more and 140 nm or less, the light reflectance at the second interface can be suppressed to below 1.0%.

[0121] <Experiment using the film structure of the electrochromic element 20 according to the third embodiment>

[0122] The film thicknesses were stacked according to the values ​​shown in Table 7 below. Figure 3 The layered structure of the electrochromic element is shown.

[0123] [Table 7]

[0124] Overall composition

[0125] Film thickness [μm] Substrate (PC) 300～ First AR layer Recorded in Table 8 Electrode layer (ITO) Recorded in Table 8 Restoration layer 3 Electrolyte layer 50 Oxide layer 1.5 Electrode layer (ITO) Recorded in Table 9 Second AR layer Recorded in Table 9 Substrate (PC) 300～

[0126] Table 7 shows the overall film structure of the third electrochromic element 30, and Tables 8 and 9 show the material structure and film thickness of each material layer constituting the AR layer, and the film thickness of the electrode layer.

[0127] It should be noted that each substrate uses a polycarbonate substrate, and each electrode layer uses ITO. Additionally, while not limited, the reduction layer uses a violet alkaloid compound, the oxide layer uses a triarylamine compound, and the electrolyte layer uses an organic gel-like material (a mixture of multiple organic salts and polymers). The refractive indices of the substrate, electrode layer, reduction layer, oxide layer, and electrolyte layer are the same as in the first embodiment.

[0128] In the experiment, the thickness of the ITO film on the reduced 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 thickness of the ITO film on the oxide layer side was changed to 100 nm (Example 5), 120 nm (Example 6), 130 nm (Example 7), and 138 nm (Example 8).

[0129] Figure 10 The spectral reflectance characteristics of electrochromic elements with fixed ITO film thicknesses of 100 nm on both the reduction layer and oxide layer sides are compared: one without an antireflection layer (comparative example), and the other with an antireflection layer (Examples 1 and 5). Figure 10 As shown, in Comparative Example 1, the wavelength at which the spectral reflectance is 0% is approximately 430 nm to 450 nm, and at wavelengths of 530 nm to 580 nm, the spectral reflectance increases to more than 3%. On the other hand, in Examples 1 and 5, the wavelength at which the spectral reflectance is 0% shifts to approximately 530 nm to 580 nm.

[0130] Figure 11 The spectral reflectance characteristics of the first interface in Examples 1 to 4 were measured by varying the thickness of the ITO film on the reduced layer side. Figure 12 The spectral reflectance characteristics of the second interface in Examples 5 to 8 were measured by varying the thickness of the ITO film on the oxide layer side.

[0131] like Figure 11 , Figure 12 As shown, in the electrochromic elements of Examples 1 to 8 with anti-reflective layers, regardless of the ITO film thickness, the spectral reflectance at wavelengths of 530 nm to 580 nm can be suppressed to a very low level. That is, according to Figure 11 , Figure 12It can be seen that the antireflective layer composition was appropriately adjusted in accordance with the ITO film thickness, so that the spectral reflectivity in the 530nm to 580nm wavelength band was almost 0%.

[0132] Next, use in Figure 11 , Figure 12 The spectral reflectance was measured, and the light reflectance ratios of the first and second interfaces were calculated according to JIS T 7334:2011. The experimental results are shown in Tables 8 and 9.

[0133] [Table 8]

[0134]

[0135] [Table 9]

[0136]

[0137] As shown in Table 8, in the configuration with an antireflective layer on the reduction layer side, by adjusting the film structure of the antireflective layer relative to the ITO film thickness, the light reflectance of the first interface can be suppressed to 1.0% or less, preferably 0.75% or less. While not limited, the ITO film thickness can be adjusted within the range of 100 nm to 136.5 nm. When the ITO film thickness is set to the range of 100 nm to 136.5 nm, the antireflective layer is configured as a stacked structure of SiO2 and ZrO2, with the SiO2 film thickness in contact with the first substrate (PC) being the thickest in the antireflective layer. Specifically, it is set to 140 nm or more and 200 nm or less. Furthermore, the ZrO2 film thickness is made thinner than the SiO2 film, approximately 2 nm to 30 nm. The total number of antireflective layers is set to 2 or 3 layers; when 3 layers are set, the SiO2 film thickness in contact with the first electrode layer (ITO) is approximately 10 nm to 60 nm.

[0138] Furthermore, in the configuration with an anti-reflective layer on the oxide layer side shown in Table 9, by adjusting the film structure of the anti-reflective layer for the ITO film thickness, the light reflectance of the second interface can be suppressed to 1.0% or less, preferably 0.45% or less. While not limited, the ITO film thickness can be adjusted within the range of 100 nm to 138 nm. When the ITO film thickness is set to the range of 100 nm to 138 nm, the anti-reflective layer is configured as a stacked structure of SiO2 and ZrO2, with the SiO2 film thickness in contact with the first substrate (PC) being the thickest in the anti-reflective layer. Specifically, it is set to 50 nm or more and 100 nm or less. The ZrO2 film thickness is thinner than the SiO2 film, set to approximately 5 nm to 30 nm. The total number of anti-reflective layers is preferably 3 or 4 layers.

[0139] Industrial applicability

[0140] The electrochromic element of the present invention can suppress the light reflectance to below 1.0%. This allows for a low level of reflection suppression, thus providing excellent wearability if the electrochromic element is used, for example, as a lens for dimming glasses.

[0141] This application is based on Japanese Special Application 2020-176814, filed on October 21, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. An electrochromic element having: a substrate, and an electrochromic film disposed in superposition with the substrate, the electrochromic film having an electrode layer and an electrochromic layer, the electrochromic element having a layer structure of a second substrate, a second electrode layer, an oxidized layer, an electrolyte layer, a reduced layer, a first electrode layer, a first substrate; the first substrate being a polycarbonate substrate, the first electrode layer being a transparent electrode having a film thickness of 123.5 nm or more and 136.5 nm or less, and / or the second substrate being a polycarbonate substrate, the second electrode layer being a transparent electrode having a film thickness of 120.5 nm or more and 138 nm or less; the refractive index of the first electrode layer and the second electrode layer being higher than the refractive index of the first substrate, the second substrate, the oxidized layer, the electrolyte layer, and the reduced layer, the refractive index of the oxidized layer, the electrolyte layer, and the reduced layer being 1.4 or more and 1.7 or less, the light reflectance of a first interface of the first electrode layer and the first substrate, and a second interface of the second electrode layer and the second substrate being 1.0% or less, respectively.

2. An electrochromic element having: a substrate, and an electrochromic film disposed in superposition with the substrate, the electrochromic film having an electrode layer and an electrochromic layer, the electrochromic element having a layer structure of a second substrate, a second electrode layer, an oxidized layer, an electrolyte layer, a reduced layer, a first electrode layer, a first substrate; the first substrate being a plastic substrate having a refractive index of 1.5, the first electrode layer being a transparent electrode having a film thickness of 125 nm or more and 135 nm or less, and / or the second substrate being a plastic substrate having a refractive index of 1.5, the second electrode layer being a transparent electrode having a film thickness of 124.5 nm or more and 134 nm or less; the refractive index of the first electrode layer and the second electrode layer being higher than the refractive index of the first substrate, the second substrate, the oxidized layer, the electrolyte layer, and the reduced layer, the refractive index of the oxidized layer, the electrolyte layer, and the reduced layer being 1.4 or more and 1.7 or less, the light reflectance of a first interface of the first electrode layer and the first substrate, and a second interface of the second electrode layer and the second substrate being 1.0% or less, respectively.

3. An electrochromic element having: a substrate, and an electrochromic film disposed in superposition with the substrate, the electrochromic film having an electrode layer and an electrochromic layer, the electrochromic element having a layer structure of a second substrate, a second electrode layer, an oxidized layer, an electrolyte layer, a reduced layer, a first electrode layer, a first substrate; the first substrate being a plastic substrate having a refractive index of 1.7, the first electrode layer being a transparent electrode having a film thickness of 125.5 nm or more and 134.5 nm or less, and / or the second substrate being a plastic substrate having a refractive index of 1.7, the second electrode layer being a transparent electrode having a film thickness of 118 nm or more and 140 nm or less; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The refractive index of the first electrode layer and the second electrode layer is higher than the refractive index of the first substrate, the second substrate, the oxidation layer, the electrolyte layer, and the reduction layer, and the refractive index of the oxidation layer, the electrolyte layer, and the reduction layer is 1.4 or more and 1.7 or less, The light 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.

4. The electrochromic element according to any one of claims 1 to 3, wherein The electrode layer is a transparent electrode layer formed of ITO, and the light reflectance of the interface with the substrate side is 1.0% or less.

5. The electrochromic element according to any one of claims 1 to 3, wherein A reflection preventing layer is provided between the substrate and the electrochromic film.

6. The electrochromic element according to claim 4, wherein A reflection preventing layer is provided between the substrate and the electrochromic film.

7. A spectacle lens which is the electrochromic element according to any one of claims 1 to 6, and the substrate is a lens substrate.

Images