JP2004325717A - Electrochromic element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which has a high contrast and good visibility when an electrochromic element is used for a display device and a dimming device which has more diverse dimming property when the electrochromic element is used as a dimming material. <P>SOLUTION: At least two or more display elements in such structure that a 1st substrate and a 2nd substrate are arranged so that their electrode layers face each other across an electrochromic layer and an electrolyte layer are laminated to constitute an elctrochromic element. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrochromic device used as a display device or a light control material.
[0002]
[Prior art]
A conventional electrochromic device includes a first electrode film (cathode) made of a transparent material such as tin oxide on a transparent material substrate such as glass, an insulating intermediate layer, an electrochromic layer made of tungsten oxide or molybdenum oxide, and a gold film. A structure in which a second electrode film (anode) is sequentially laminated (for example, see Patent Document 1), or a display substrate and a substrate in which a transparent electrode and an electrochromic layer made of tungsten oxide, molybdenum oxide, or the like are formed on a transparent substrate This structure has a structure in which a counter substrate on which a counter electrode is formed is interposed with a spacer, and an electrolytic layer made of an electrolytic solution or a solid electrolyte is provided between the substrates (for example, see Patent Document 2).
[0003]
[Patent Document 1]
JP-B-52-46098 (pages 3-5)
[0004]
[Patent Document 2]
JP-A-59-113422 (page 1-2)
[0005]
[Problems to be solved by the invention]
However, when an electrochromic element having a single electrochromic layer is used for, for example, a display device, the single layer has a small color, and therefore, it has been considered to increase the thickness of the electrochromic layer in order to obtain a dark color. However, when the electrochromic layer is made thicker, it takes time for the electrochromic layer to be completely colored, resulting in a problem such as a reduction in display speed. In addition, when used as a light modulating material, in addition to the above-mentioned problems of the display device, in a single layer, coloring is limited to one type, and a range in which light transmittance can be changed is limited. However, it was impossible to completely block the light by reflecting visible light. For these reasons, the electrochromic element has not been widely applied as a display device or a light control material.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. When used in a display device, the present invention provides a display device having a high response speed, high contrast, and high visibility. It is an object of the present invention to provide a light control device having more various light control properties when used as a light material.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the electrochromic device of the present invention has a first substrate on which a first electrode layer is formed, a second substrate on which a second electrode layer is formed, and a first electrode layer. An electrochromic layer formed on one of the electrode layers of the second electrode layer and electrically changing light transmittance in the visible light region, and an electrolyte layer, the first electrode layer and the second At least two or more display elements having a structure in which the first substrate and the second substrate are arranged so that the two electrode layers face each other with the electrolyte layer interposed therebetween are stacked. Alternatively, a first element constituted by providing an electrochromic layer and an electrolyte layer between the electrode layer of the upper substrate and one electrode layer of the intermediate substrate, and the other electrode of the electrode layer of the lower substrate and the intermediate substrate A second element constituted by providing an electrochromic layer and an electrolyte layer between the layers was provided.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the electrochromic device of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic partial cross-sectional view of an embodiment having a configuration in which two electrochromic elements are stacked. As shown in the figure, the electrochromic device 1 is configured such that an electrochromic layer 4 and an electrolyte layer 5 are provided between an upper substrate 2A on which an electrode layer 3 is formed and a lower substrate 2B. Are stacked in two elements.
[0009]
Here, as a method of forming the electrolyte layer 5, a solid electrolyte is formed by overlapping, or a liquid or gel electrolyte layer is filled in a gap formed by opposing the electrochromic layer 4 and the lower substrate 2B. And other methods are possible. For the upper substrate 2A and the lower substrate 2B, a material having a light-transmitting property and having at least a non-conductive surface is used. For example, glass, acrylic resin, styrene resin, polycarbonate resin, polymethylpentene resin, methyl methacrylate / styrene copolymer resin, or the like can be used.
[0010]
As the electrode layer 3, a transparent conductive film, for example, indium-tin oxide (ITO), fluorine-tin oxide (FTO), zinc oxide, tin oxide, a transparent conductive polymer, or the like can be used. As the electrochromic layer 4, molybdenum oxide, iridium oxide, vanadium oxide, tungsten oxide, nickel oxide, nickel magnesium alloy, viologen, pyrazoline, phenylenediamine, phenazine, phenoxazine, phenothiazine, polythiophene, polyaniline, polypyrrole, metal phthalocyanine, tetra Thiafulvalene, ferrocene, and derivatives thereof can be used. Any one of these materials may be used for all the electrochromic layers 4, or a different material may be used for each of the electrochromic layers 4. When a different material is used for each electrochromic layer 4, it is possible to make different colors appear by selecting a layer to be colored. When a material (for example, a nickel magnesium alloy) having a substantially uniform reflectance in a visible light region in a colored state is used for the electrochromic layer 4, it is possible to completely block visible light. . The electrode layer 3 and the electrochromic layer 4 may be formed on the entire surface of the substrate, patterned in accordance with display contents, or patterned in a matrix.
[0011]
As the electrolyte layer 5, any of a liquid electrolyte, a gel electrolyte, and a solid electrolyte can be used. As the liquid electrolyte, for example, a solution in which a supporting electrolyte such as a salt, an acid, or an alkali is dissolved in a solvent can be used. The solvent in this case is not particularly limited as long as it can dissolve the supporting electrolyte, but a solvent showing a polarity is particularly preferable. Specifically, water, methanol, ethanol, propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, acetonitrile, γ-butyrolactone, sulfolane, 1,3-dioxane, N, N-dimethylformamide, 1,2-dimethoxyethane And organic polar solvents of tetrahydrofuran, and these can be used alone or as a mixture. The salts used as the supporting electrolyte are not particularly limited, and examples thereof include various alkali metal salts, inorganic ionic salts of alkaline earth metal salts, quaternary ammonium salts, cyclic quaternary ammonium salts, and quaternary phosphonium salts. Specifically, LiClO4, LiSCN, LiBF4, LiAsF6, LiCF3SO3, LiPF6, LiI, NaI, NaSCN, NaClO4, NaBF4, NaAsF6, KSCN, and alkali metal salts of Li, Na, K of KCl; (CH3) 4NBF4, ( The quaternary ammonium salt and cyclic quaternary ammonium salt of (C2H5) 4NBF4, (n-C4H9) 4NBF4, (C2H5) 4NBr, (C2H5) 4NClO4 and (n-C4H9) 4NClO4, and mixtures thereof. The acids used as the supporting electrolyte are not particularly limited, and inorganic acids and organic acids can be used, and include sulfuric acid, hydrochloric acid, phosphoric acids, sulfonic acids and carboxylic acids. The alkalis as the supporting electrolyte are not particularly limited, and include sodium hydroxide, potassium hydroxide, and lithium hydroxide.
[0012]
As the gel electrolyte, a viscous liquid obtained by further adding a polymer or a gelling agent to the above-mentioned liquid electrolyte, or a gel electrolyte can be used. The polymer is not particularly limited, and examples thereof include polyacrylonitrile, carboxymethylcellulose, polyvinyl chloride, polyethylene oxide, polyurethane, polyacrylate, polymethacrylate, polyamide, polyacrylamide, cellulose, polyester, polypropylene oxide and Nafion (registered trademark). Can be The gelling agent is not particularly limited, and examples thereof include oxyethylene methacrylate, oxyethylene acrylate, urethane acrylate, acrylamide and agar. The gel electrolyte is prepared by mixing a monomer as a precursor of a polymer or a precursor of a gelling agent with a liquid electrolyte, injecting the mixture into the gap between the electrochromic layer 4 and the lower substrate 2A, and then polymerizing or gelling. Thereby, it can be formed between the opposing electrochromic layer 4 and the lower substrate 2A.
[0013]
The solid electrolyte is not particularly limited as long as it is a solid at room temperature and has ionic conductivity. Specific examples thereof include polyethylene oxide, a polymer of oxyethylene methacrylate, Nafion (registered trademark) and polystyrene sulfonic acid. Is raised. It is also preferable to use a solid polymer electrolyte.
[0014]
FIG. 2 is a schematic partial cross-sectional view showing an embodiment in which two electrochromic layers are formed. As shown in the drawing, the electrochromic element 1 has an intermediate substrate 6 having an electrochromic layer 4 and an electrode layer 3 formed on both surfaces thereof, between an upper substrate 2A having an electrode layer 3 formed thereon and a lower substrate 2B, and an electrolyte. A layer 5 is provided.
[0015]
FIG. 3 is a schematic partial sectional view showing an example of a configuration in which three electrochromic layers are formed. As shown in the figure, an electrochromic element 1 has intermediate substrates 6A and 6B each having an electrochromic layer 4 and an electrode layer 3 formed on both surfaces between an upper substrate 2A and a lower substrate 2B each having an electrode layer 3 formed thereon. And an electrolyte layer 5. Similarly, the number of intermediate substrates can be increased, and the number of electrochromic layers can be any number.
[0016]
FIG. 4 is a schematic diagram illustrating a control method of the electrochromic device 1. In the electrochromic element 1, the control circuit 7 can independently control the coloration and decoloration of the electrochromic layer 4. Therefore, it is possible to control the coloring and decoloring of each electrochromic layer 4 simultaneously or separately.
[0017]
【The invention's effect】
According to the present invention, when used as a display device, since there are two or more electrochromic layers, it is possible to express a plurality of colors by selecting materials having different color tones as the electrochromic layers. If a material having the same color tone at the time of coloring is selected, a high response speed and a high contrast can be obtained at the same time. In addition, when lamination is performed using an intermediate substrate having electrode layers formed on both surfaces, a reduction in thickness can be realized. When used as a light modulating material, in addition to the effect obtained when the device is used as a display device, one layer of the electrochromic layer is made of a material having a substantially uniform reflectance in the visible light region, so that it is stepped by coloring. In addition, since it becomes easy to completely control the visible light transmittance as well as to completely block the visible light, it is possible to provide a light control device having more various light control properties.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view schematically illustrating a configuration of an electrochromic device of the present invention. FIG. 2 is a partial cross-sectional view schematically illustrating a configuration of an electrochromic device of the present invention. FIG. FIG. 4 is a schematic cross-sectional view schematically showing the configuration of the electrochromic device of the present invention.
DESCRIPTION OF SYMBOLS 1 Electrochromic element 2A Upper substrate 2B Lower substrate 3 Electrode layer 4 Electrochromic layer 5 Electrolyte layer 6A First intermediate substrate 6B Second intermediate substrate 7 Control circuit

Claims (6)

A first substrate on which a first electrode layer is formed, a second substrate on which a second electrode layer is formed, and any one of the first electrode layer and the second electrode layer An electrochromic layer formed on top and electrically changing light transmittance in a visible light region, and an electrolyte layer,
At least two or more display elements having a structure in which the first substrate and the second substrate are arranged such that the first electrode layer and the second electrode layer face each other with the electrolyte layer interposed therebetween An electrochromic device characterized by being performed. An upper substrate on which an electrode layer made of a conductive material is formed,
A lower substrate on which an electrode layer made of a conductive material is formed,
At least one intermediate substrate having an electrode layer made of a conductive material formed on both surfaces,
A first electrode layer formed by providing an electrochromic layer and an electrolyte layer capable of electrically changing light transmittance in a visible light region between an electrode layer of the upper substrate and an electrode layer of the intermediate substrate. Of the element,
A second electrode layer formed by providing an electrochromic layer and an electrolyte layer capable of electrically changing light transmittance in a visible light region between the electrode layer of the lower substrate and the electrode layer of the intermediate substrate. Of the element,
An electrochromic device comprising: The electrochromic device according to claim 2, wherein the electrochromic layer of the first device and the electrochromic layer of the second device are made of different materials. The electrochromic device according to claim 2, wherein the electrochromic layer of the first device and the electrochromic layer of the second device are colored in different colors. The electrochromic device according to any one of claims 2 to 4, wherein a pixel pattern formed by the first element and a pixel pattern formed by the outer second element are the same. 4. The method according to claim 3, wherein one of the electrochromic layer of the first element and the electrochromic layer of the second element is made of a material having a substantially uniform reflectance in a visible light region. Electrochromic device.

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